KAS IV: a 3-ketoacyl-ACP synthase from Cuphea sp. is a medium chain specific condensing enzyme.

PubMed

Dehesh, K; Edwards, P; Fillatti, J; Slabaugh, M; Byrne, J

1998-08-01

cDNA clones encoding a novel 3-ketoacyl-ACP synthase (KAS) have been isolated from Cuphea. The amino acid sequence of this enzyme is different from the previously characterized classes of KASs, designated KAS I and III, and similar to those designated as KAS II. To define the acyl chain specificity of this enzyme, we generated transgenic Brassica plants over-expressing the cDNA encoded protein in a seed specific manner. Expression of this enzyme in transgenic Brassica seeds which normally do not produce medium chain fatty acids does not result in any detectable modification of the fatty acid profile. However, co-expression of the Cuphea KAS with medium chain specific thioesterases, capable of production of either 12:0 or 8:0/10:0 fatty acids in seed oil, strongly enhances the levels of these medium chain fatty acids as compared with seed oil of plants expressing the thioesterases alone. By contrast, co-expression of the Cuphea KAS along with an 18:0/18.1-ACP thioesterase does not result in any detectable modification of the fatty acids. These data indicate that the Cuphea KAS reported here has a different acyl-chain specificity to the previously characterized KAS I, II and III. Therefore, we designate this enzyme KAS IV, a medium chain specific condensing enzyme.

A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Junwei; Zhang, Huan; Fang, Liurong

Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferasemore » by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis.« less

Immune responses and protective efficacy of the gene vaccine expressing Ag85B and ESAT6 fusion protein from Mycobacterium tuberculosis.

PubMed

Chang-hong, Shi; Xiao-wu, Wang; Hai, Zhang; Ting-fen, Zhang; Li-Mei, Wang; Zhi-kai, Xu

2008-04-01

Genetic immunity is a new promising approach for the development of novel tuberculosis vaccines. In this study, it is shown that DNA vaccines expressing the fusion protein of antigen 85B (Ag85B) and early secreted antigenic target 6-kDa antigen (ESAT6) can induce high levels of specific IgG2a antibody subtype in the mice. With the prolongation of postimmunization time, the levels of IgG2a antibody decrease gradually. Although a high-level specific IgG2a antibody subtype is also elicited by classical BCG, the ratio of antibody subtypes IgG2a to IgG1 changes 4 weeks after immunization, and IgG1 is gradually shifted to the main antibody subtype. DNA vaccines also elicit cellular immunity as shown by specific spleen lymphocytes proliferation to Ag85B or ESAT6 protein and the production of high levels of IFN-gamma and IL-2, which is similar to that elicited by BCG. Vaccination of mice with DNA vaccines expressing the fusion protein Ag85B-ESAT6 results in a significant level of protection against the subsequent high-dose challenge with virulent Mycobacterium tuberculosis (MTB) H37Rv. Dramatic reduction in the number of MTB colony-forming units in the spleens and lungs is observed. Pathological examination showed that recombinant plasmid and BCG groups have only minor damage and organizational structures that are kept relatively complete, while in the control group, spleens and lungs are damaged seriously. Therefore, although the reducing degree of mycobacterial loads in the organ of mice immunized with recombinant plasmid is not more than that of BCG, through the analysis of pathological changes, we may conclude that the protective effect provided by DNA vaccine expressing the Ag85B-ESAT6 fusion protein is equivalent to that afforded by the classical BCG.

The application of anti-ESAT-6 monoclonal antibody fluorescent probe in ex vivo near-infrared fluorescence imaging in mice with pulmonary tuberculosis.

PubMed

Feng, Feng; Zhang, Haoling; Zhu, Zhaoqin; Li, Cong; Shi, Yuxin; Zhang, Zhiyong

2014-09-01

Here, we aimed to assess the feasibility of anti-ESAT-6 monoclonal antibody (mAb) coupling with IR783 and rhodamine fluorescent probe in the detection of ESAT-6 expression in tuberculosis tissue of mice using near-infrared fluorescence imaging. IR783 and rhodamine were conjugated to the anti-ESAT-6 mAb or IgG. Mice in the experimental group were injected with fluorescence-labeled mAb probe, and mice in the control group were injected with fluorescence-labeled non-specific IgG antibody. Twenty-four hours later, the lung tissue of mice was examined using ex vivo near-infrared fluorescence imaging. In addition, the contrast-to-noise ratio (CNR) was calculated by measuring the signal intensities of the pulmonary lesions, normal lung tissue and background noise. The frozen lung tissue section was examined under fluorescence microscopy and compared with hemoxylin and eosin (HE) staining. The ex vivo near-infrared fluorescence imaging showed that the fluorescence signal in the lung tuberculosis lesions in the experimental group was significantly enhanced, whereas there was only a weak fluorescence signal or even no fluorescence signal in the control group. CNR values were 64.40 ± 7.02 (n = 6) and 8.75 ± 3.87 (n = 6), respectively (t = 17.01, p < 0.001). The fluorescence accumulation distribution detected under fluorescence microscopy was consistent with HE staining of the tuberculosis region. In conclusion, anti-ESAT-6 mAb fluorescent probe could target and be applied in specific ex vivo imaging of mice tuberculosis, and may be of further use in tuberculosis in living mice. Copyright © 2013 John Wiley & Sons, Ltd.

Signal Regulatory Protein alpha (SIRPalpha)+ Cells in the Adaptive Response to ESAT-6/CFP-10 Protein of Tuberculous Mycobacteria

USDA-ARS?s Scientific Manuscript database

Early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10(CFP-10) are co-secreted proteins of Mycobacterium tuberculosis complex mycobacteria (includes M. bovis, the zoonotic agent of bovine tuberculosis) involved in phagolysosome escape of the bacillus and, potentially, in the eff...

User's guide for the Nimbus 7 ERB Solar Analysis Tape (ESAT)

NASA Technical Reports Server (NTRS)

Hickey, J. R.; Major, E. R.; Kyle, H. L.

1984-01-01

Five years of Nimbus 7 ERB solar data is available in compact form on a single ERB solar analysis tape (ESAT). The period covered is November 16, 1978 through October 31, 1983. The Nimbus 7 satellite performs just under 14 orbits a day and the ERB solar telescope observe the Sun once per orbit as the satellite passes + or - near the south pole. The data were carefully calibrated and screened. Mean orbital and daily values are given for the total solar irradiance plus selected spectral intervals. In addition, selected solar activity indicators are on the tape. The ERB experiment, the solar data calibration and screening procedures, the solar activity indicators, and the tape format are described briefly.

Recombinant ESAT-6-CFP10 Fusion Protein Induction of Th1/Th2 Cytokines and FoxP3 Expressing Treg Cells in Pulmonary TB.

PubMed

Jackson-Sillah, Dolly; Cliff, Jacqueline M; Mensah, Gloria Ivy; Dickson, Emmanuel; Sowah, Sandra; Tetteh, John K A; Addo, Kwasi K; Ottenhoff, Tom H M; Bothamley, Graham; Dockrell, Hazel M

2013-01-01

Early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) are Mycobacterium tuberculosis (Mtb)-specific antigens that are secreted by actively metabolising bacteria and contribute to the virulence of the bacteria. Their ability to induce Treg and Th2 responses, particularly during the first two weeks of treatment, has not been comprehensively examined to date. The purpose of this work was to characterise Th1, Th2 and Treg responses to rESAT-6-CFP10 fusion protein in TB patients before and during the intensive phase of treatment and in healthy M.bovis BCG vaccinated donors. Forty-six newly diagnosed, HIV-negative, smear-positive pulmonary TB patients and 20 healthy donors were recruited in the UK and Ghana. Their peripheral blood mononuclear cells (PBMC) were used in ex vivo ELISPOT and in vitro cultures to identify immunological parameters of interest. The study confirmed that protective immune responses to rESAT-6-CFP10 are impaired in active TB but improved during treatment: circulating antigen-specific IL-4-producing T-cells were increased in untreated TB but declined by two weeks of treatment while the circulating antigen-specific IFN-γ producing T cells which showed a transient rise at one week of treatment, persisted at baseline levels at two months of treatment. In vitro T cell proliferation and IFN-γ production were reduced, while IL-4 and CD4(+)FoxP3(+)CD25(hi) cell expression were increased in response to rESAT-6-CFP10 fusion protein in untreated TB. These responses were reversed during early treatment of TB. These observations support further investigations into the possible utility of these parameters as markers of active disease and favourable treatment outcomes.

Recombinant ESAT-6-CFP10 Fusion Protein Induction of Th1/Th2 Cytokines and FoxP3 Expressing Treg Cells in Pulmonary TB

PubMed Central

Jackson-Sillah, Dolly; Cliff, Jacqueline M.; Mensah, Gloria Ivy; Dickson, Emmanuel; Sowah, Sandra; Tetteh, John K A.; Addo, Kwasi K.; Ottenhoff, Tom H. M.; Bothamley, Graham; Dockrell, Hazel M.

2013-01-01

Background Early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) are Mycobacterium tuberculosis (Mtb)–specific antigens that are secreted by actively metabolising bacteria and contribute to the virulence of the bacteria. Their ability to induce Treg and Th2 responses, particularly during the first two weeks of treatment, has not been comprehensively examined to date. The purpose of this work was to characterise Th1, Th2 and Treg responses to rESAT-6-CFP10 fusion protein in TB patients before and during the intensive phase of treatment and in healthy M.bovis BCG vaccinated donors. Methods Forty-six newly diagnosed, HIV-negative, smear-positive pulmonary TB patients and 20 healthy donors were recruited in the UK and Ghana. Their peripheral blood mononuclear cells (PBMC) were used in ex vivo ELISPOT and in vitro cultures to identify immunological parameters of interest. Results The study confirmed that protective immune responses to rESAT-6-CFP10 are impaired in active TB but improved during treatment: circulating antigen-specific IL-4-producing T-cells were increased in untreated TB but declined by two weeks of treatment while the circulating antigen-specific IFN-γ producing T cells which showed a transient rise at one week of treatment, persisted at baseline levels at two months of treatment. In vitro T cell proliferation and IFN-γ production were reduced, while IL-4 and CD4+FoxP3+CD25hi cell expression were increased in response to rESAT-6-CFP10 fusion protein in untreated TB. These responses were reversed during early treatment of TB. Conclusions These observations support further investigations into the possible utility of these parameters as markers of active disease and favourable treatment outcomes. PMID:23826366

ESAT-6–dependent cytosolic pattern recognition drives noncognate tuberculosis control in vivo

PubMed Central

Zedler, Ulrike; Stäber, Manuela; Perdomo, Carolina; Dorhoi, Anca

2016-01-01

IFN-γ is a critical mediator of host defense against Mycobacterium tuberculosis (Mtb) infection. Antigen-specific CD4+ T cells have long been regarded as the main producer of IFN-γ in tuberculosis (TB), and CD4+ T cell immunity is the main target of current TB vaccine candidates. However, given the recent failures of such a TB vaccine candidate in clinical trials, strategies to harness CD4-independent mechanisms of protection should be included in future vaccine design. Here, we have reported that noncognate IFN-γ production by Mtb antigen–independent memory CD8+ T cells and NK cells is protective during Mtb infection and evaluated the mechanistic regulation of IFN-γ production by these cells in vivo. Transfer of arenavirus- or protein-specific CD8+ T cells or NK cells reduced the mortality and morbidity rates of mice highly susceptible to TB in an IFN-γ–dependent manner. Secretion of IFN-γ by these cell populations required IL-18, sensing of mycobacterial viability, Mtb protein 6-kDa early secretory antigenic target–mediated (ESAT-6–mediated) cytosolic contact, and activation of NLR family pyrin domain–containing protein 3 (NLRP3) inflammasomes in CD11c+ cell subsets. Neutralization of IL-18 abrogated protection in susceptible recipient mice that had received noncognate cells. Moreover, improved Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine–induced protection was lost in the absence of ESAT-6–dependent cytosolic contact. Our findings provide a comprehensive mechanistic framework for antigen-independent IFN-γ secretion in response to Mtb with critical implications for future intervention strategies against TB. PMID:27111234

The recombinant fusion protein CFP10-ESAT6-dIFN has protective effect against tuberculosis in guinea pigs.

PubMed

Permyakova, Natalya V; Belavin, Pavel A; Pirozhkova, Dariya S; Ufimtseva, Elena G; Rozov, Sergey M; Mursalimov, Sergey R; Sidorchuk, Yuriy V; Uvarova, Elena A; Zagorskaya, Alla A; Marenkova, Tatiana V; Bannikova, Svetlana V; Demidov, Evgeniy A; Starostin, Konstantin V; Kravchenko, Marionella A; Vakhrusheva, Diana V; Berdnikov, Roman B; Eremeeva, Natalya I; Skornyakov, Sergey N; Peltek, Sergey E; Deineko, Elena V

2018-03-01

Development of effective vaccine candidates against tuberculosis (TB) is currently the most important challenge in the prevention of this disease since the BCG vaccine fails to guarantee a lifelong protection, while any other approved vaccine with better efficiency is still absent. The protective effect of the recombinant fusion protein CFP10-ESAT6-dIFN produced in a prokaryotic expression system (Escherichia coli) has been assessed in a guinea pig model of acute TB. The tested antigen comprises the Mycobacterium tuberculosis (Mtb) proteins ESAT6 and CFP10 as well as modified human γ-interferon (dIFN) for boosting the immune response. Double intradermal immunization of guinea pigs with the tested fusion protein (2 × 0.5 µg) induces a protective effect against subsequent Mtb infection. The immunized guinea pigs do not develop the symptoms of acute TB and their body weight gain was five times more as compared with the non-immunized infected guinea pigs. The animal group immunized with this dose of antigen displays the minimum morphological changes in the internal organs and insignificant inflammatory lesions in the liver tissue, which complies with a decrease in the bacterial load in the spleen and average Mtb counts in macrophages.

Sarcoidosis Th17 Cells are ESAT-6 Antigen Specific but Demonstrate Reduced IFN-γ Expression

PubMed Central

Richmond, Bradley W.; Ploetze, Kristen; Isom, Joan; Chambers-Harris, Isfahan; Braun, Nicole A.; Taylor, Thyneice; Abraham, Susamma; Mageto, Yolanda; Culver, Dan A.; Oswald-Richter, Kyra A.; Drake, Wonder P.

2013-01-01

Rationale Sarcoidosis is a granulomatous disease of unknown etiology. Many patients with sarcoidosis demonstrate antigen-specific immunity to mycobacterial virulence factors. Th-17 cells are crucial to the immune response in granulomatous inflammation, and have recently been shown to be present in greater numbers in the peripheral blood and bronchoalveolar lavage (BAL) fluid (BALF) of sarcoidosis patients than healthy controls. It is unclear whether Th-17 cells in sarcoidosis are specific for mycobacterial antigens, or whether they have similar functionality to control Th-17 cells. Methods Flow cytometry was used to determine the numbers of Th-17 cells present in the peripheral blood and BALF of patients with sarcoidosis, the percentage of Th-17 cells that were specific to the mycobacterial virulence factor ESAT-6, and as well as to assess IFN-γ expression in Th-17 cells following polyclonal stimulation. Results Patients with sarcoidosis had greater numbers of Th-17 cells in the peripheral blood and BALF than controls and produced significantly more extracellular IL-17A (p=0.03 and p=0.02, respectively). ESAT-6 specific Th-17 cells were present in both peripheral blood and BALF of sarcoidosis patients (p<0.001 and p=0.03, respectively). After polyclonal stimulation, Th-17 cells from sarcoidosis patients produced less IFN-γ than healthy controls. Conclusions Patients with sarcoidosis have mycobacterial antigen-specific Th-17 cells peripherally and in sites of active sarcoidosis involvement. Despite the Th1 immunophenotype of sarcoidosis immunology, the Th-17 cells have reduced IFN-γ expression, compared to healthy controls. This reduction in immunity may contribute to sarcoidosis pathogenesis. PMID:23073617

Serodiagnostic potential of immuno-PCR using a cocktail of mycobacterial antigen 85B, ESAT-6 and cord factor in tuberculosis patients.

PubMed

Singh, Netrapal; Sreenivas, Vishnubhatla; Sheoran, Abhishek; Sharma, Suman; Gupta, Krishna B; Khuller, Gopal K; Mehta, Promod K

2016-01-01

A novel indirect immuno-polymerase chain reaction (I-PCR) assay was developed for the detection of circulating anti-Ag85B (antigen 85B, Rv1886c), anti-ESAT-6 (early secretory antigenic target-6, Rv3875) and anti-cord factor (trehalose 6,6'-dimycolate) antibodies from the sera samples of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients and the results were compared with an analogous enzyme-linked immunosorbent assay (ELISA). We covalently attached the amino-modified reporter DNA to the dithiothreitol (DTT)-reduced anti-human IgG antibody through a chemical linker succinimidyl 4-[N-maleimidomethyl]-cyclohexane-1-carboxylate (SMCC). The detection of cocktail of anti-Ag85B, anti-ESAT-6 and anti-cord factor antibodies was found to be superior to the detection of individual antibodies. The sensitivities of 89.5% and 77.5% with I-PCR and 70.8% and 65% with ELISA were observed in smear-positive and smear-negative PTB cases, respectively with high specificity (90.9%). On the other hand, a sensitivity of 77.5% with I-PCR and 65% with ELISA was observed in EBTB cases. The detection of cocktail of antibodies by I-PCR is likely to improve the utility of existing algorithms for TB diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Structural Basis for the Recognition of Mycolic Acid Precursors by KasA, a Condensing Enzyme and Drug Target from Mycobacterium Tuberculosis *

PubMed Central

Schiebel, Johannes; Kapilashrami, Kanishk; Fekete, Agnes; Bommineni, Gopal R.; Schaefer, Christin M.; Mueller, Martin J.; Tonge, Peter J.; Kisker, Caroline

2013-01-01

The survival of Mycobacterium tuberculosis depends on mycolic acids, very long α-alkyl-β-hydroxy fatty acids comprising 60–90 carbon atoms. However, despite considerable efforts, little is known about how enzymes involved in mycolic acid biosynthesis recognize and bind their hydrophobic fatty acyl substrates. The condensing enzyme KasA is pivotal for the synthesis of very long (C38–42) fatty acids, the precursors of mycolic acids. To probe the mechanism of substrate and inhibitor recognition by KasA, we determined the structure of this protein in complex with a mycobacterial phospholipid and with several thiolactomycin derivatives that were designed as substrate analogs. Our structures provide consecutive snapshots along the reaction coordinate for the enzyme-catalyzed reaction and support an induced fit mechanism in which a wide cavity is established through the concerted opening of three gatekeeping residues and several α-helices. The stepwise characterization of the binding process provides mechanistic insights into the induced fit recognition in this system and serves as an excellent foundation for the development of high affinity KasA inhibitors. PMID:24108128

Molecular and eco-physiological characterization of arsenic (As)-transforming Achromobacter sp. KAs 3-5T from As-contaminated groundwater of West Bengal, India.

PubMed

Mohapatra, Balaram; Satyanarayana, Tulasi; Sar, Pinaki

2018-05-02

Molecular and eco-physiological characterization of arsenic (As)-transforming and hydrocarbon-utilizing Achromobacter type strain KAs 3-5 T has been investigated in order to gain an insight into As-geomicrobiology in the contaminated groundwater. The bacterium is isolated from As-rich groundwater of West Bengal, India. Comparative 16S rRNA gene sequence phylogenetic analysis confirmed that the strain KAs 3-5 T is closely related to Achromobacter mucicolens LMG 26685 T (99.17%) and Achromobacter animicus LMG 26690 T (99.17%), thus affiliated to the genus Achromobacter. Strain KAs 3-5 T is nonflagellated, mesophilic, facultative anaerobe, having a broad metabolic repertoire of using various sugars, sugar-/fatty acids, hydrocarbons as principal carbon substrates, and O 2 , NO 3 - , NO 2 - , and Fe 3+ as terminal electron acceptors. Growth with hydrocarbons led to cellular aggregation and adherence of the cells to the hydrocarbon particles confirmed through electron microscopic observations. The strain KAs 3-5 T showed high As resistance (MIC of 5 mM for As 3+ , 25 mM for As 5+ ) and reductive transformation of As 5+ under aerobic conditions while utilizing both sugars and hydrocarbons. Molecular taxonomy specified a high genomic GC content (65.5 mol %), ubiquinone 8 (UQ-8) as respiratory quinone, spermidine as predominant polyamine in the bacterium. The differential presence of C 12:0 , C 14:0 2-OH, C 18:1 ω7c, and C 14:0 iso 3-OH/ C 16:1 iso fatty acids, phosphatidylglycerol (PG), phosphatidylcholine (PC), two unknown phospholipid (PL1, PL2) as polar lipids, low DNA-DNA relatedness (33.0-41.0%) with the Achromobacter members, and unique metabolic capacities clearly indicated the distinct genomic and physiological properties of strain KAs 3-5 T among known species of the genus Achromobacter. These findings lead to improve our understanding on metabolic flexibility of bacteria residing in As-contaminated groundwater and As-bacteria interactions within oligotrophic

SRTM Colored and Shaded Topography: Haro and Kas Hills, India

NASA Image and Video Library

2001-04-12

On January 26, 2001, the Kachchh region in western India suffered the most deadly earthquake in India's history. This shaded topography view of landforms northeast of the city of Bhuj depicts geologic structures that are of interest in the study the tectonic processes that may have led to that earthquake. However, preliminary field studies indicate that these structures are composed of Mesozoic rocks that are overlain by younger rocks showing little deformation. Thus these structures may be old, not actively growing, and not directly related to the recent earthquake. The Haro Hills are on the left and the Kas Hills are on the right. The Haro Hills are an "anticline," which is an upwardly convex elongated fold of layered rocks. In this view, the anticline is distinctly ringed by an erosion resistant layer of sandstone. The east-west orientation of the anticline may relate to the crustal compression that has occurred during India's northward movement toward, and collision with, Asia. In contrast, the largest of the Kas Hills appears to be a tilted (to the south) and faulted (on the north) block of layered rocks. Also seen here, the linear feature trending toward the southwest from the image center is an erosion-resistant "dike," which is an igneous intrusion into older "host" rocks along a fault plane or other crack. These features are simple examples of how shaded topography can provide a direct input to geologic studies. In this image, colors show the elevation as measured by the Shuttle Radar Topography Mission (SRTM). Colors range from green at the lowest elevations, through yellow and red, to purple at the highest elevations. Elevations here range from near sea level to about 300 meters (about 1000 feet). Shading has been added, with illumination from the north (image top). http://photojournal.jpl.nasa.gov/catalog/PIA03300

Bioelectrochemical Detection of Mycobacterium tuberculosis ESAT-6 in an Antibody-Based Biomicrosystem

PubMed Central

Sepulveda, Danna; Varela, Andres; Del Portillo, Patricia

2017-01-01

Bioelectrochemical sensing of Mycobacterium tuberculosis through electro-immunosensors is a promising technique to detect relevant analytes. In general, immunosensors require the formation of organic assemblies by the adsorption of molecular constituents. Moreover, they depend on the correct immobilization of the bio-recognition element in the biosensor. These procedures cannot be easily monitored without the use of invasive methods. In this work, an impedance analysis technique was used, as a non-invasive method, to measure and differentiate the manufacturing stages of the sensors. Biomicrosystems were fabricated through physical vapor deposition (PVD) of 80 nm Au nanolayers on 35 µm copper surfaces. Later, the surface was modified through thiolation methods generating a self-assembled-monolayer (SAM) with 20 mM 4-aminothiophenol (4-ATP) on which a polyclonal antibody (pAb) was covalently attached. Using impedance analysis, every step of the electro-immunosensor fabrication protocol was characterized using 40 independent replicas. Results showed that, compared to the negative controls, distilled water, and 0.5 µg/mL HSA, a maximum variation of 171% between each replica was achieved when compared to samples containing 0.5 µg/mL of ESAT-6 M. tuberculosis immunodominant protein. Therefore, this development validates a non-invasive method to electrically monitor the assembly process of electro-immunosensors and a tool for its further measure for detection of relevant antigens. PMID:28937645

Measuring smoking knowledge, attitudes and services (S-KAS) among clients in addiction treatment

PubMed Central

Guydish, Joseph; Tajima, Barbara; Chan, Mable; Delucchi, Kevin L.; Ziedonis, Douglas

2010-01-01

Background Addiction treatment programs are increasingly working to address prevalent and comorbid tobacco dependence in their service populations. However at present there are few published measurement tools, with known psychometric properties, that can be used to assess client-level constructs related to tobacco dependence in addiction treatment settings. Following on previous work that developed a staff-level survey instrument, this report describes the development and measurement characteristics of the Smoking Knowledge, Attitudes and Services (S-KAS) for use with clients in addiction treatment settings. Method 250 clients enrolled in residential drug abuse treatment programs were surveyed. Summary statistics were used to characterize both the participants and their responses, and exploratory factor analysis (EFA) was used to examine the underlying factor structure. Results Examination of the rotated factor pattern indicated that the latent structure was formed by one Knowledge factor, one Attitude factor, and two “service” factors reflecting Program Services and Clinician Services related to tobacco dependence. Standardized Cronbach’s alpha coefficients for the four scales were, respectively, .57, .75, .82 and .82. Conclusions The proposed scales have reasonably good psychometric characteristics, although the knowledge scale leaves room for improvement, and will allow researchers to quantify client knowledge, attitudes and services regarding tobacco dependence treatment. Researchers, program administrators, and clinicians may find the S-KAS useful in changing organizational culture and clinical practices related to tobacco addiction, help in program evaluation studies, and in tracking and improving client motivation. PMID:21055884

Influence of ESAT-6 secretion system 1 (RD1) of Mycobacterium tuberculosis on the interaction between mycobacteria and the host immune system.

PubMed

Majlessi, Laleh; Brodin, Priscille; Brosch, Roland; Rojas, Marie-Jésus; Khun, Huot; Huerre, Michel; Cole, Stewart T; Leclerc, Claude

2005-03-15

The chromosomal locus encoding the early secreted antigenic target, 6 kDa (ESAT-6) secretion system 1 of Mycobacterium tuberculosis, also referred to as "region of difference 1 (RD1)," is absent from Mycobacterium bovis bacillus Calmette-Guerin (BCG). In this study, using low-dose aerosol infection in mice, we demonstrate that BCG complemented with RD1 (BCG::RD1) displays markedly increased virulence which albeit does not attain that of M. tuberculosis H37Rv. Nevertheless, phenotypic and functional analyses of immune cells at the site of infection show that the capacity of BCG::RD1 to initiate recruitment/activation of immune cells is comparable to that of fully virulent H37Rv. Indeed, in contrast to the parental BCG, BCG::RD1 mimics H37Rv and induces substantial influx of activated (CD44highCD45RB(-)CD62L(-)) or effector (CD45RB(-)CD27(-)) T cells and of activated CD11c(+)CD11bhigh cells to the lungs of aerosol-infected mice. For the first time, using in vivo analysis of transcriptome of inflammatory cytokines and chemokines of lung interstitial CD11c+ cells, we show that in a low-dose aerosol infection model, BCG::RD1 triggered an activation/inflammation program comparable to that induced by H37Rv while parental BCG, due to its overattenuation, did not initiate the activation program in lung interstitial CD11c+ cells. Thus, products encoded by the ESAT-6 secretion system 1 of M. tuberculosis profoundly modify the interaction between mycobacteria and the host innate and adaptive immune system. These modifications can explain the previously described improved protective capacity of BCG::RD1 vaccine candidate against M. tuberculosis challenge.

Specificity of the Tuberculin Skin Test Is Modified by Use of a Protein Cocktail Containing ESAT-6 and CFP-10 in Cattle Naturally Infected with Mycobacterium bovis

PubMed Central

Flores-Villalva, S.; Suárez-Güemes, F.; Espitia, C.; Whelan, A. O.; Vordermeier, M.

2012-01-01

The mycobacterial immunodominant ESAT-6 and CFP-10 antigens are strongly recognizable in tuberculosis-infected cattle, and they do not elicit a response in cattle without infection. In addition, they are absent in most environmental mycobacterial species, and therefore, their use can be an alternative to purified protein derivative (PPD) tuberculin in the development of a more specific skin diagnostic test in cattle. The aim of the current study was to assess the potential of an ESAT-6 and CFP-10 (E6-C10) protein cocktail in a skin test format in naturally tuberculosis-infected and paratuberculosis-infected cattle. We also included MPB83 as a third component in one of the protein cocktail preparations. The protein cocktail was tested at different dose concentrations (5, 10, and 15 μg per protein). The best skin response to the E6-C10 protein cocktail was obtained with 10 μg. Subsequently, this concentration was tested in 2 herds with high and low bovine tuberculosis prevalence, the latter with paratuberculosis coinfection. Our data show that the E6-C10 cocktail allows identification of an important proportion of animals that PPDB is not able to recognize, especially in low-prevalence herds. The protein cocktail did not induce reactions in tuberculosis-free cattle or in paratuberculosis-infected cattle. Addition of MPB83 to the protein cocktail did not make any difference in the skin reaction. PMID:22419675

Specificity of the tuberculin skin test is modified by use of a protein cocktail containing ESAT-6 and CFP-10 in cattle naturally infected with Mycobacterium bovis.

PubMed

Flores-Villalva, S; Suárez-Güemes, F; Espitia, C; Whelan, A O; Vordermeier, M; Gutiérrez-Pabello, J A

2012-05-01

The mycobacterial immunodominant ESAT-6 and CFP-10 antigens are strongly recognizable in tuberculosis-infected cattle, and they do not elicit a response in cattle without infection. In addition, they are absent in most environmental mycobacterial species, and therefore, their use can be an alternative to purified protein derivative (PPD) tuberculin in the development of a more specific skin diagnostic test in cattle. The aim of the current study was to assess the potential of an ESAT-6 and CFP-10 (E6-C10) protein cocktail in a skin test format in naturally tuberculosis-infected and paratuberculosis-infected cattle. We also included MPB83 as a third component in one of the protein cocktail preparations. The protein cocktail was tested at different dose concentrations (5, 10, and 15 μg per protein). The best skin response to the E6-C10 protein cocktail was obtained with 10 μg. Subsequently, this concentration was tested in 2 herds with high and low bovine tuberculosis prevalence, the latter with paratuberculosis coinfection. Our data show that the E6-C10 cocktail allows identification of an important proportion of animals that PPDB is not able to recognize, especially in low-prevalence herds. The protein cocktail did not induce reactions in tuberculosis-free cattle or in paratuberculosis-infected cattle. Addition of MPB83 to the protein cocktail did not make any difference in the skin reaction.

Effect of Ayurveda Medications (Kasīsa Bhasma and Dhātrī Avaleha) on Iron Deficiency Anaemia: A Randomized Controlled Study

PubMed Central

Tubaki, Basavaraj Ramappa; Benni, Jyoti Mahadev; Rao, Niranjan; Prasad, Uchangi Nagaraja Rao

2016-01-01

Background: This paper explores the role that Ayurveda can play in the management of Iron Deficiency Anaemia, a major nutritional deficiency disorder affecting people across the globe. Methodology: Forty (40) patients suffering from Iron deficiency anaemia as per WHO guidelines, between the age group of 20 to 60 yrs of either sex participated in the study. Study was a randomized, controlled, open label clinical study. Patients were randomly divided into two groups: Group D (n = 20) received Dhārī avaleha 10 g twice a day after food. Group K (n = 20) received capsules Kasīsa bhasma 125 mg thrice a day. Both interventions were administered for 30 days and the subjects were followed up for next 30 days with placebo capsules to assess the sustainability of the effects. Assessments were done at baseline, 30th and 60th days. Primary outcome measure was hemoglobin estimation (Hb) and secondary outcome measures were the other hematological parameters such as Red blood cell (RBC) indices, total RBC count, Packed Cell volume (PCV) and Peripheral Blood smear study. Results: Both interventions produced significant improvements (P < 0.001). Kasīsa bhasma was better compared to dhātrī avaleha in terms of primary (P < 0.0001) and secondary outcomes. Comparison of outcomes from base line – 30th day, base line – 60th day and 30th – 60th day showed significant (P < 0.0001) improvement in both the groups in parameters such as haemoglobin, MCV and MCH. Hence improvements sustained during placebo intervened sustainability period also. Conclusions: Study effectively shows that Kasīsa bhasma is better then Dhātrī avaleha. Improvements by both interventions were sustained even during the sustainability period. PMID:28182020

Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model

PubMed Central

Cervantes-Villagrana, Alberto R.; Hernández-Pando, Rogelio; Biragyn, Arya; Castañeda-Delgado, Julio; Bodogai, Monica; Martínez-Fierro, Margarita; Sada, Eduardo; Trujillo, Valentin; Enciso-Moreno, Antonio; Rivas-Santiago, Bruno

2018-01-01

The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0–89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. PMID:23196205

Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model.

PubMed

Cervantes-Villagrana, Alberto R; Hernández-Pando, Rogelio; Biragyn, Arya; Castañeda-Delgado, Julio; Bodogai, Monica; Martínez-Fierro, Margarita; Sada, Eduardo; Trujillo, Valentin; Enciso-Moreno, Antonio; Rivas-Santiago, Bruno

2013-01-11

The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. Copyright © 2012 Elsevier Ltd. All rights reserved.

SRTM Colored and Shaded Topography: Haro and Kas Hills, India

NASA Technical Reports Server (NTRS)

2001-01-01

On January 26, 2001, the Kachchh region in western India suffered the most deadly earthquake in India's history. This shaded topography view of landforms northeast of the city of Bhuj depicts geologic structures that are of interest in the study the tectonic processes that may have led to that earthquake. However, preliminary field studies indicate that these structures are composed of Mesozoic rocks that are overlain by younger rocks showing little deformation. Thus these structures may be old, not actively growing, and not directly related to the recent earthquake.

The Haro Hills are on the left and the Kas Hills are on the right. The Haro Hills are an 'anticline,' which is an upwardly convex elongated fold of layered rocks. In this view, the anticline is distinctly ringed by an erosion resistant layer of sandstone. The east-west orientation of the anticline may relate to the crustal compression that has occurred during India's northward movement toward, and collision with, Asia. In contrast, the largest of the Kas Hills appears to be a tilted (to the south) and faulted (on the north) block of layered rocks. Also seen here, the linear feature trending toward the southwest from the image center is an erosion-resistant 'dike,' which is an igneous intrusion into older 'host' rocks along a fault plane or other crack. These features are simple examples of how shaded topography can provide a direct input to geologic studies.

In this image, colors show the elevation as measured by the Shuttle Radar Topography Mission (SRTM). Colors range from green at the lowest elevations, through yellow and red, to purple at the highest elevations. Elevations here range from near sea level to about 300 meters (about 1000 feet). Shading has been added, with illumination from the north (image top).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Hu, E-mail: austhudong@126.com; Medical Inspection Center, Anhui University of Science and Technology, Huainan; Jing, Wu, E-mail: wujing8008@126.com

In recent years, increasing studies have found that pathogenic Mycobacterium tuberculosis (Mtb) inhibits autophagy, which mediates the anti-mycobacterial response, but the mechanism is not clear. We previously reported that secretory acid phosphatase (SapM) of Mtb can negatively regulate autophagy flux. Recently, another virulence factor of Mtb, early secretory antigenic target 6 (ESAT6), has been found to be involved in inhibiting autophagy, but the mechanism remains unclear. In this study, we show that ESAT6 hampers autophagy flux to boost bacillus Calmette-Guerin (BCG) proliferation and reveals a mechanism by which ESAT6 blocks autophagosome-lysosome fusion in a mammalian target of rapamycin (MTOR)-dependent manner.more » In both Raw264.7 cells and primary macrophages derived from the murine abdominal cavity (ACM), ESAT6 repressed autophagy flux by interfering with the autophagosome-lysosome fusion, which resulted in an increased load of BCG. Impaired degradation of LC3Ⅱ and SQSTM1 by ESAT6 was related to the upregulated activity of MTOR. Contrarily, inhibiting MTOR with Torin1 removed the ESAT6-induced autophagy block and lysosome dysfunction. Furthermore, in both Raw264.7 and ACM cells, MTOR inhibition significantly suppressed the survival of BCG. In conclusion, our study highlights how ESAT6 blocks autophagy and promotes BCG survival in a way that activates MTOR. - Highlights: • A mechanism for disruping autophagy flux induced by ESAT6. • ESAT6-inhibited autophagy is MTOR-dependent. • ESAT6-boosted BCG is MTOR-dependent.« less

Early Secreted Antigenic Target of 6 kDa of Mycobacterium tuberculosis Stimulates Macrophage Chemoattractant Protein-1 Production by Macrophages and Its Regulation by p38 Mitogen-Activated Protein Kinases and Interleukin-4.

PubMed

Ma, J; Jung, B-G; Yi, N; Samten, B

2016-07-01

Early secreted antigenic target of 6 kDa (ESAT-6), the major virulence factor of Mycobacterium tuberculosis, affects host immunity and the formation of granulomas likely through inflammatory cytokines. To understand its role in this regard further, we investigated the effect of ESAT-6 on macrophages by determining the production of macrophage chemoattractant protein (MCP)-1, a major chemokine associated with tuberculosis pathogenesis, by murine bone marrow-derived macrophages (BMDMs) and its regulation by protein kinases and cytokines. The results revealed that ESAT-6, but not Ag85A and culture filtrate protein 10 kDa (CFP10), induced MCP-1 production by BMDMs dose and time dependently. Inhibition of p38 but not other mitogen-activated protein kinases (MAPK) and PI3K further enhanced ESAT-6-induced MCP-1 production by BMDMs. Inhibition of p38 MAPK enhanced ESAT-6-induced MCP-1 mRNA accumulation without affecting mRNA stability. ESAT-6 also induced TNF-α from BMDMs and MCP-1 from mouse lung epithelial cells, and these were suppressed by p38 MAPK inhibition, implying cytokine- and cell-specific effect of p38 MAPK inhibition on ESAT-6-induced MCP-1 by macrophages. Pretreatment of BMDMs with IL-4, but not other cytokines (IL-2, IL-10, TNF-α, IFN-γ and IL-1α) further elevated ESAT-6-stimulated MCP-1 production although IL-4 did not induce MCP-1 without ESAT-6. Both p38 MAPK inhibitor and IL-4 did not show additive effect on ESAT-6-induced MCP-1 protein level despite such effect on MCP-1 mRNA level was evident. In conclusion, these results indicate a specific role for both p38 MAPK and IL-4 in ESAT-6-induced MCP-1 production by macrophages and suggest a pathway with significance in tuberculosis pathogenesis. © 2016 The Foundation for the Scandinavian Journal of Immunology.

Site Area Boundaries

EPA Pesticide Factsheets

This dataset consists of site boundaries from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times and were combined into one region-wide layer. Thus far the sources include:1. California Gulch (Irrigated Meadows) - ESAT Contractor.2. Manning Canyon - U.S. EPA Region 8; ESAT Contractor.3. Rapid City Small Arms Range - U.S. EPA Region 8; ESAT Contractor.4. Animas River/Cement Creek - U.S. EPA Region 8; ESAT Contractor.5. Monticello Mill Tailings (USDOE) - USDOE; ESAT Contractor.6. Pinon Canyon - USDOD.7. Rock Flats Industrial Park - U.S. EPA Region 8.8. Bountiful/Woods Cross - U.S. EPA Region 8.9. Lincoln Park - U.S. EPA Region 8.10. Marshall Landfill - U.S. EPA Region 8.11. U.S. Magnesium - Pacific Western Technologies Inc.

Induction of cytotoxic T lymphocyte response against Mycobacterial antigen using domain I of anthrax edema factor as antigen delivery system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandra, Subhash; Kaur, Manpreet; Midha, Shuchi

2007-05-25

We have investigated the efficiency of N-terminal 1-260 residues of Edema factor (EFn) as a delivery system for ESAT-6, an antigenic protein of Mycobacterium tuberculosis H{sub 37}R{sub v}, into the cytosol of mammalian cells. The EFn.ESAT-6 recombinant protein was obtained by genetic fusion of EFn and ESAT-6 DNA. Our data shows that in the presence of PA, EFn.ESAT-6 fusion protein is internalized into the cytosol of antigen presenting cells, and the splenocytes produced both Th1 and Th2 cytokines in vitro. Further, EFn.ESAT-6 elicited effective cytotoxicT lymphocyte (CTL) response in an in vitro CTL assay. This study for the first timemore » demonstrates that EFn can be used as a vehicle to deliver heterologous proteins of therapeutic importance.« less

Mycobacteria-specific cytokine responses as correlates of treatment response in active and latent tuberculosis.

PubMed

Clifford, Vanessa; Tebruegge, Marc; Zufferey, Christel; Germano, Susie; Forbes, Ben; Cosentino, Lucy; McBryde, Emma; Eisen, Damon; Robins-Browne, Roy; Street, Alan; Denholm, Justin; Curtis, Nigel

2017-08-01

A biomarker indicating successful tuberculosis (TB) therapy would assist in determining appropriate length of treatment. This study aimed to determine changes in mycobacteria-specific antigen-induced cytokine biomarkers in patients receiving therapy for latent or active TB, to identify biomarkers potentially correlating with treatment success. A total of 33 adults with active TB and 36 with latent TB were followed longitudinally over therapy. Whole blood stimulation assays using mycobacteria-specific antigens (CFP-10, ESAT-6, PPD) were done on samples obtained at 0, 1, 3, 6 and 9 months. Cytokine responses (IFN-γ, IL-1ra, IL-2, IL-10, IL-13, IP-10, MIP-1β, and TNF-α) in supernatants were measured by Luminex xMAP immunoassay. In active TB cases, median IL-1ra (with CFP-10 and with PPD stimulation), IP-10 (CFP-10, ESAT-6), MIP-1β (ESAT-6, PPD), and TNF-α (ESAT-6) responses declined significantly over the course of therapy. In latent TB cases, median IL-1ra (CFP-10, ESAT-6, PPD), IL-2 (CFP-10, ESAT-6), and IP-10 (CFP-10, ESAT-6) responses declined significantly. Mycobacteria-specific cytokine responses change significantly over the course of therapy, and their kinetics in active TB differ from those observed in latent TB. In particular, mycobacteria-specific IL-1ra responses are potential correlates of successful therapy in both active and latent TB. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Characterization of culture filtrate proteins Rv1197 and Rv1198 of ESAT-6 family from Mycobacterium tuberculosis H37Rv.

PubMed

Pandey, Himanshu; Tripathi, Sarita; Srivastava, Kanchan; Tripathi, Dinesh K; Srivastava, Mrigank; Kant, Surya; Srivastava, Kishore K; Arora, Ashish

2017-02-01

We have characterized two immunogenic proteins, Rv1197 and Rv1198, of the Esx-5 system of the ESAT-6 family of Mycobacterium tuberculosis H37Rv. The complex formation between Rv1197 and Rv1198 was characterized by biophysical techniques. The reactivity of serum from TB patients towards these proteins was characterized by ELISA. Lymphocyte proliferation and cytokine induction were followed in restimulated splenocytes from immunized mice by using MTT assay and CBA flowcytometry, respectively. Rv1197 and Rv1198 strongly interact to form a heterodimeric complex under reducing conditions, which is characterized by a dissociation constant of 97×10 -9 M and melting temperature, Tm, of 50.5°C. Strong humoral responses to Rv1197, Rv1198, CFP-10 and MoaC1 (Rv3111) antigens were found in Indian patients with active pulmonary tuberculosis (n=44), in comparison to non-infected healthy individuals (n=20). The seroreactivity to Rv1198 was characterized by a sensitivity of 75% and specificity of 90%. In BALB/c mice, immunization with Rv1198-FIA induced a pro-inflammatory response with elevated levels of TNF and IL-6, along with low induction of IFN-γ, IL-2 and IL-10, but no induction of IL-4. Rv1197 and Rv1198 form a stable complex, which is regulated by the redox state of Rv1198. Rv1198 is immunogenic with highly specific seroreactivity towards TB patients' serum. Rv1198 elicits a pro-inflammatory recall response in immunized mice. This study characterizes the interaction of Rv1197 and Rv1198, and establishes the immunogenic nature of Rv1198. Copyright © 2016 Elsevier B.V. All rights reserved.

Bacterial polyester inclusions engineered to display vaccine candidate antigens for use as a novel class of safe and efficient vaccine delivery agents.

PubMed

Parlane, Natalie A; Wedlock, D Neil; Buddle, Bryce M; Rehm, Bernd H A

2009-12-01

Bioengineered bacterial polyester inclusions have the potential to be used as a vaccine delivery system. The biopolyester beads were engineered to display a fusion protein of the polyester synthase PhaC and the two key antigens involved in immune response to the infectious agent that causes tuberculosis, Mycobacterium tuberculosis, notably antigen 85A (Ag85A) and the 6-kDa early secreted antigenic target (ESAT-6) from Mycobacterium tuberculosis. Polyester beads displaying the respective fusion protein at a high density were successfully produced (henceforth called Ag85A-ESAT-6 beads) by recombinant Escherichia coli. The ability of the Ag85A-ESAT-6 beads to enhance mouse immunity to the displayed antigens was investigated. The beads were not toxic to the animals, as determined by weight gain and absence of lesions at the inoculation site in immunized animals. In vivo injection of the Ag85A-ESAT-6 beads in mice induced significant humoral and cell-mediated immune responses to both Ag85A and ESAT-6. Vaccination with Ag85A-ESAT-6 beads was efficient at stimulating immunity on their own, and this ability was enhanced by administration of the beads in an oil-in-water emulsion. In addition, vaccination with the Ag85A-ESAT-6 beads induced significantly stronger humoral and cell-mediated immune responses than vaccination with an equivalent dose of the fusion protein Ag85A-ESAT-6 alone. The immune response induced by the beads was of a mixed Th1/Th2 nature, as assessed from the induction of the cytokine gamma interferon (Th1 immune response) and increased levels of immunoglobulin G1 (Th2 immune response). Hence, engineered biopolyester beads displaying foreign antigens represent a new class of versatile, safe, and biocompatible vaccines.

Assessment of a Protein Cocktail-Based Skin Test for Bovine Tuberculosis in a Double-Blind Field Test in Cattle

PubMed Central

Xin, Ting; Jia, Hong; Ding, Jiabo; Li, Pingjun; Yang, Hongjun; Hou, Shaohua; Yuan, Weifeng; Guo, Xiaoyu; Wang, Haichun; Liang, Qianqian; Li, Ming

2013-01-01

Bovine tuberculosis (bTB) is a worldwide zoonosis caused mainly by Mycobacterium bovis. The traditional diagnostic method used often is the tuberculin skin test, which uses bovine purified protein derivatives (PPD-B). However, it is difficult to maintain uniformity of PPD-B from batch to batch, and it shares common antigens with nonpathogenic environmental mycobacteria. To overcome these problems, M. bovis-specific antigens that showed good T cell stimulation, such as CFP-10, ESAT-6, Rv3615c, etc., have been used in the skin test, but there have been no large-scale clinical studies on these antigens. In this study, two combinations (CFP-10/ESAT-6/TB10.4 protein cocktail and CFP-10/ESAT-6/Rv3872/MPT63 protein cocktail) were developed and used as stimuli in the skin test. Cattle were double-blind tested to assess the efficiency of the protein cocktail-based skin tests. The results showed that the CFP-10/ESAT-6/TB10.4 protein cocktail-based skin test can differentiate TB-infected cattle from Mycobacterium avium-infected ones and that it shows a high degree of agreement with the traditional tuberculin skin test (κ = 0.8536) and gamma interferon (IFN-γ) release assay (κ = 0.8154). Compared to the tuberculin skin test, the relative sensitivity and relative specificity of the CFP-10/ESAT-6/TB10.4-based skin test were 87% and 97%, respectively., The relative sensitivity and relative specificity of the CFP-10/ESAT-6/TB10.4-based skin test were 93% and 92%, respectively, on comparison with the IFN-γ release assay. The correlation between the increases in skin thickness observed after the inoculation of stimuli was high (PPD-B versus CFP-10/ESAT-6/TB10.4, Spearman r of 0.8435). The correlation between the optical density at 450 nm (OD450) obtained after blood stimulation with PPD-B and the increase in skin thickness observed after inoculation of the CFP-10/ESAT-6/TB10.4 protein cocktail was high (Spearman r = 0.7335). Therefore, the CFP-10/ESAT-6/TB10.4-based skin test

Examining Users' E-Satisfaction in the Usage of Social Networking Sites; Contribution from Utilitarian and Hedonic Information Systems

NASA Astrophysics Data System (ADS)

Ariff, Mohd Shoki Md; Shan, Tay Kai; Zakuan, Norhayati; Ishak, Nawawi; Ridzuan Wahi, Mohd

2014-06-01

E-satisfaction (eSAT) is an important success factor of online service providers such as social networking sites (SNSs). The utilitarian and hedonic information systems are crucial in determining users' eSAT of SNSs, especially among young users. The utilitarian aspect of an information system is productivity-oriented which aims to enhance the users' task performance, and it is important in measuring eSAT of SNSs. In this study, the original constructs of Perceived Ease of Use (PEOU) and Perceived Usefulness (PU) of TAM of utilitarian information system was first developed in this research framework. The use of SNSs, such as Facebook, is pleasure-oriented, in which self-fulfilling values to the users are important in determining users' satisfaction towards the SNSs. Therefore, Perceived Enjoyment (PE) of hedonic information system is added to the framework. Thus, the research framework of this study includes both utilitarian (PEOU and PU) and hedonic (PE) aspects of information systems to determine Malaysian young users' eSAT in the usage of Facebook, a social networking site. In this framework, the effects of PEOU, PU and PE on eSAT in the usage of Facebook are examined among Facebook's users in the age of 18 - 24 years old. The effects of PEOU on PU and PE are also examined. Online questionnaire survey was employed and a total of 384 sets of questionnaires were gathered from users of Facebook. The results indicated that PEOU has positive effects on PU and PE in the context of Facebook. In addition, PEOU, PU and PE are also found to have positive effects on eSAT. PE of hedonic information system exerted higher effect on eSAT, compared to PEOU and PU of utilitarian information system, highlighting the importance of pleasure orientation in the usage of Facebook of SNSs. Managerial and theoretical implications of the study are discussed in term of measuring and enhancing users' eSAT in the usage of SNSs, particularly Facebook.

A Novel ESAT-6 Secretion System-Secreted Protein EsxX of Community-Associated Staphylococcus aureus Lineage ST398 Contributes to Immune Evasion and Virulence.

PubMed

Dai, Yingxin; Wang, Yanan; Liu, Qian; Gao, Qianqian; Lu, Huiying; Meng, Hongwei; Qin, Juanxiu; Hu, Mo; Li, Min

2017-01-01

The ESAT-6 secretion system (ESS) has been reported to contribute to the virulence and pathogenicity of several Staphylococcus aureus strains such as USA300 and Newman. However, the role of the ESS in community-associated S. aureus (CA-SA) lineage ST398 in China is not well understood. By comparing the ess locus of ST398 with the published S. aureus sequence in the NCBI database, we found one gene in the ess locus encoding a novel WXG superfamily protein that is highly conserved only in ST398. LC-MS/MS and Western blot analysis revealed that this protein is a novel secreted protein controlled by the ST398 ESS, and we named the protein EsxX. Although EsxX was not under the control of the accessory gene regulator like many other virulence factors and had no influence on several phenotypes of ST398, such as growth, hemolysis, and biofilm formation, it showed important impacts on immune evasion and virulence in ST398. An esxX deletion mutant led to significantly reduced resistance to neutrophil killing and decreased virulence in murine skin and blood infection models, indicating its essential contribution to the evasion of innate host defense and virulence to support the pathogenesis of ST398 infections. The function of this novel secreted protein EsxX might help us better understand the role of the ESS in the virulence and epidemic success of the CA-SA lineage ST398.

CFP-10 from Mycobacterium tuberculosis Selectively Activates Human Neutrophils through a Pertussis Toxin-Sensitive Chemotactic Receptor

PubMed Central

Björnsdottir, Halla; Winther, Malene; Christenson, Karin; Oprea, Tudor; Karlsson, Anna; Forsman, Huamei; Dahlgren, Claes; Bylund, Johan

2014-01-01

Upon infection with Mycobacterium tuberculosis, neutrophils are massively recruited to the lungs, but the role of these cells in combating the infection is poorly understood. Through a type VII secretion system, M. tuberculosis releases a heterodimeric protein complex, containing a 6-kDa early secreted antigenic target (ESAT-6) and a 10-kDa culture filtrate protein (CFP-10), that is essential for virulence. Whereas the ESAT-6 component possesses multiple virulence-related activities, no direct biological activity of CFP-10 has been shown, and CFP-10 has been described as a chaperone protein for ESAT-6. We here show that the ESAT-6:CFP-10 complex induces a transient release of Ca2+ from intracellular stores in human neutrophils. Surprisingly, CFP-10 rather than ESAT-6 was responsible for triggering the Ca2+ response, in a pertussis toxin-sensitive manner, suggesting the involvement of a G-protein-coupled receptor. In line with this, the response was accompanied by neutrophil chemotaxis and activation of the superoxide-producing NADPH-oxidase. Neutrophils were unique among leukocytes in responding to CFP-10, as monocytes and lymphocytes failed to produce a Ca2+ signal upon stimulation with the M. tuberculosis protein. Hence, CFP-10 may contribute specifically to neutrophil recruitment and activation during M. tuberculosis infection, representing a novel biological role for CFP-10 in the ESAT-6:CFP-10 complex, beyond the previously described chaperone function. PMID:25332123

Low Cost Tuberculosis Vaccine Antigens in Capsules: Expression in Chloroplasts, Bio-Encapsulation, Stability and Functional Evaluation In Vitro

PubMed Central

Yang, Xiangdong; Lloyd, Bethany; Daniell, Henry

2013-01-01

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading fatal infectious diseases. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, three candidate antigens, ESAT-6 (6kDa early secretory antigenic target) and Mtb72F (a fusion polyprotein from two TB antigens, Mtb32 and Mtb39) fused with cholera toxin B-subunit (CTB) and LipY (a cell wall protein) were expressed in tobacco and/or lettuce chloroplasts to facilitate bioencapsulation/oral delivery. Site-specific transgene integration into the chloroplast genome was confirmed by Southern blot analysis. In transplastomic leaves, CTB fusion proteins existed in soluble monomeric or multimeric forms of expected sizes and their expression levels varied depending upon the developmental stage and time of leaf harvest, with the highest-level of accumulation in mature leaves harvested at 6PM. The CTB-ESAT6 and CTB-Mtb72F expression levels reached up to 7.5% and 1.2% of total soluble protein respectively in mature tobacco leaves. Transplastomic CTB-ESAT6 lettuce plants accumulated up to 0.75% of total leaf protein. Western blot analysis of lyophilized lettuce leaves stored at room temperature for up to six months showed that the CTB-ESAT6 fusion protein was stable and preserved proper folding, disulfide bonds and assembly into pentamers for prolonged periods. Also, antigen concentration per gram of leaf tissue was increased 22 fold after lyophilization. Hemolysis assay with purified CTB-ESAT6 protein showed partial hemolysis of red blood cells and confirmed functionality of the ESAT-6 antigen. GM1-binding assay demonstrated that the CTB-ESAT6 fusion protein formed pentamers to bind with the GM1-ganglioside receptor. The expression of functional Mycobacterium tuberculosis antigens in transplastomic plants should facilitate development of a cost-effective and orally deliverable TB booster vaccine with potential for long

Diagnostic accuracy of intracellular mycobacterium tuberculosis detection for tuberculous meningitis.

PubMed

Feng, Guo-dong; Shi, Ming; Ma, Lei; Chen, Ping; Wang, Bing-ju; Zhang, Min; Chang, Xiao-lin; Su, Xiu-chu; Yang, Yi-ning; Fan, Xin-hong; Dai, Wen; Liu, Ting-ting; He, Ying; Bian, Ting; Duan, Li-xin; Li, Jin-ge; Hao, Xiao-ke; Liu, Jia-yun; Xue, Xin; Song, Yun-zhang; Wu, Hai-qin; Niu, Guo-qiang; Zhang, Li; Han, Cui-juan; Lin, Hong; Lin, Zhi-hui; Liu, Jian-jun; Jian, Qian; Zhang, Jin-she; Tian, Ye; Zhou, Bai-yu; Wang, Jing; Xue, Chang-hu; Han, Xiao-fang; Wang, Jian-feng; Wang, Shou-lian; Thwaites, Guy E; Zhao, Gang

2014-02-15

Early diagnosis and treatment of tuberculous meningitis saves lives, but current laboratory diagnostic tests lack sensitivity. We investigated whether the detection of intracellular bacteria by a modified Ziehl-Neelsen stain and early secretory antigen target (ESAT)-6 in cerebrospinal fluid leukocytes improves tuberculous meningitis diagnosis. Cerebrospinal fluid specimens from patients with suspected tuberculous meningitis were stained by conventional Ziehl-Neelsen stain, a modified Ziehl-Neelsen stain involving cytospin slides with Triton processing, and an ESAT-6 immunocytochemical stain. Acid-fast bacteria and ESAT-6-expressing leukocytes were detected by microscopy. All tests were performed prospectively in a central laboratory by experienced technicians masked to the patients' final diagnosis. Two hundred and eighty patients with suspected tuberculous meningitis were enrolled. Thirty-seven had Mycobacterium tuberculosis cultured from cerebrospinal fluid; 40 had a microbiologically confirmed alternative diagnosis; the rest had probable or possible tuberculous meningitis according to published criteria. Against a clinical diagnostic gold standard the sensitivity of conventional Ziehl-Neelsen stain was 3.3% (95% confidence interval, 1.6-6.7%), compared with 82.9% (95% confidence interval, 77.4-87.3%) for modified Ziehl-Neelsen stain and 75.1% (95% confidence interval, 68.8-80.6%) for ESAT-6 immunostain. Intracellular bacteria were seen in 87.8% of the slides positive by the modified Ziehl-Neelsen stain. The specificity of modified Ziehl-Neelsen and ESAT-6 stain was 85.0% (95% confidence interval, 69.4-93.8%) and 90.0% (95% confidence interval, 75.4-96.7%), respectively. Enhanced bacterial detection by simple modification of the Ziehl-Neelsen stain and an ESAT-6 intracellular stain improve the laboratory diagnosis of tuberculous meningitis.

[Immunobiologic characteristics of a recombinant Listeria monocytogenes expressing Mycobacterium tuberculosis antigens].

PubMed

Yin, Yuelan; Zhao, Dan; Kang, Meiqin; Tan, Weijun; Lian, Kai; Hu, Maozhi; Chen, Xiang; Pan, Zhiming; Jiao, Xin'an

2013-12-04

Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis complex. Hence, novel vaccines against TB are urgently needed and important to the public health. Immunobiologic characteristics of a recombinant attenuated Listeria monocytogenes strain LMdeltahly: :Ag85b-esat-6 was evaluated. LMdeltahly: :Ag85b-esat-6 had lost the hemolytic activity. It was completely cleared from the livers and spleens of mice 5 days after inoculation via intravenous route. Furthermore, the LD50 of the recombinant strain increased by 4 Logs comparing to that of the parent strain. Histopathology reveals no obvious pathological changes following administration of the recombinant strain to mice, indicating its safety. In addition, the potential protective immune response was evaluated on C57BL/6 mice via intravenous immunization route. The results indicate that the antigen delivered by the recombination LM could induce Th1 type immune response and elicit strong cytotoxic lymphocyte effect against Ag85B-ESAT-6. Thus, LMdeltahly::Ag85b-esat-6 had high safety to mice, and could be used as a novel vaccines candidate for preventing tuberculosis.

APC targeting enhances immunogenicity of a novel multistage Fc-fusion tuberculosis vaccine in mice.

PubMed

Soleimanpour, Saman; Farsiani, Hadi; Mosavat, Arman; Ghazvini, Kiarash; Eydgahi, Mohammad Reza Akbari; Sankian, Mojtaba; Sadeghian, Hamid; Meshkat, Zahra; Rezaee, Seyed Abdolrahim

2015-12-01

Numerous studies have demonstrated that targeting immunogens to FcγR on antigen-presenting cells (APCs) can selectively uptake and increase cellular immunity in vitro and in vivo. Therefore, the present study was conducted to evaluate immunogenicity of a novel multistage tuberculosis vaccine, a combination of an early and a dormant immunogenic protein, ESAT6 and HspX, fused to Fcγ2a fragment of mouse IgG2a to target all forms of tuberculosis. Codon-optimized genes consisting of ESAT6, a linker, and HspX fused either to mouse Fcγ2a (ESAT6:HspX:mFcγ2a) or 6× His-tag (ESAT6:HspX:His) were synthesized. The resulting proteins were then produced in Pichia pastoris. The fusion proteins were separately emulsified in dimethyldioctadecylammonium bromide(DDA)-trehalose-6,6-dibehenate(TDB) adjuvant, and their immunogenicity with and without bacille Calmette-Guérin (BCG) was assessed in C57BL/6 mice. Th1, Th2, Th17, and T-reg cytokine patterns were evaluated using the ELISA method. Both multistage vaccines induced very strong IL-12 and IFN-γ secretion from splenic cells; the Fc-tagged subunit vaccine induced a more effective Th1 immune response (IFN-γ, 910 pg/mL, and IL-12, 854 pg/mL) with a very low increase in IL-17 (∼0.1 pg/mL) and IL-4 (37 pg/mL) and a mild increase in TGF-β (543 pg/mL) compared to the BCG or ESAT6:HspX:His primed and boosted groups. The production of IFN-γ to ESAT6:HspX:Fcγ2a was very consistent and showed an increasing trend for IL-12 compared to the BCG or ESAT6:HspX:His primed and boosted groups. Fcγ2a used as a delivery vehicle supported the idea of selective uptake, inducing cross-presentation and forming a proper anti-tuberculosis response in context of Th1/Th2 and Th17/T-reg balances, which is important for protection and prevention of damage.

MprAB regulates the espA operon in Mycobacterium tuberculosis and modulates ESX-1 function and host cytokine response.

PubMed

Pang, Xiuhua; Samten, Buka; Cao, Guangxiang; Wang, Xisheng; Tvinnereim, Amy R; Chen, Xiu-Lan; Howard, Susan T

2013-01-01

The ESX-1 secretion system exports the immunomodulatory protein ESAT-6 and other proteins important in the pathogenesis of Mycobacterium tuberculosis. Components and substrates of ESX-1 are encoded at several loci, but the regulation of the encoding genes is only partially understood. In this study, we investigated the role of the MprAB two-component system in the regulation of ESX-1 activity. We determined that MprAB directly regulates the espA gene cluster, a locus necessary for ESX-1 function. Transcript mapping determined that the five genes in the cluster form an operon with two transcriptional start points, and several MprA binding sites were detected in the espA promoter. Expression analyses and promoter constructs indicated that MprAB represses the espA operon. However, the MprAB mutant Rv-D981 secreted lower levels of EspA, ESAT-6, and the ESX-1 substrate EspB than control strains. Secretion of CFP10, which is normally cosecreted with ESAT-6, was similar in Rv-D981 and control strains, further demonstrating aberrant ESX-1 activity in the mutant. ESAT-6 induces proinflammatory cytokines, and macrophages infected with Rv-D981 elicited lower levels of interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α), consistent with the reduced levels of ESAT-6. These findings indicate that MprAB modulates ESX-1 function and reveal a new role for MprAB in host-pathogen interactions.

The role of beta-ketoacyl-acyl carrier protein synthase III in the condensation steps of fatty acid biosynthesis in sunflower.

PubMed

González-Mellado, Damián; von Wettstein-Knowles, Penny; Garcés, Rafael; Martínez-Force, Enrique

2010-05-01

The beta-ketoacyl-acyl carrier protein synthase III (KAS III; EC 2.3.1.180) is a condensing enzyme catalyzing the initial step of fatty acid biosynthesis using acetyl-CoA as primer. To determine the mechanisms involved in the biosynthesis of fatty acids in sunflower (Helianthus annuus L.) developing seeds, a cDNA coding for HaKAS III (EF514400) was isolated, cloned and sequenced. Its protein sequence is as much as 72% identical to other KAS III-like ones such as those from Perilla frutescens, Jatropha curcas, Ricinus communis or Cuphea hookeriana. Phylogenetic study of the HaKAS III homologous proteins infers its origin from cyanobacterial ancestors. A genomic DNA gel blot analysis revealed that HaKAS III is a single copy gene. Expression levels of this gene, examined by Q-PCR, revealed higher levels in developing seeds storing oil than in leaves, stems, roots or seedling cotyledons. Heterologous expression of HaKAS III in Escherichia coli altered their fatty acid content and composition implying an interaction of HaKAS III with the bacterial FAS complex. Testing purified HaKAS III recombinant protein by adding to a reconstituted E. coli FAS system lacking condensation activity revealed a novel substrate specificity. In contrast to all hitherto characterized plant KAS IIIs, the activities of which are limited to the first cycles of intraplastidial fatty acid biosynthesis yielding C6 chains, HaKAS III participates in at least four cycles resulting in C10 chains.

Evaluation of Mycobacterium tuberculosis Early Secreted Antigenic Target 6 Recombinant Protein as a Diagnostic Marker in Skin Test.

PubMed

Moradi, Jale; Mosavari, Nader; Ebrahimi, Mahmoud; Arefpajohi, Reza; Tebianian, Majid

2015-02-01

Tuberculosis (TB) is the leading infectious disease in the developing world. Delayed-type hypersensitivity skin test diagnoses TB using tuberculin purified protein derivative (PPD), but this test is incapable of distinguishing Mycobacterium tuberculosis (MTB) infection from bacillus Calmette-Guérin (BCG) vaccination or an infection caused by nontuberculous mycobacteria (NTM). This study was performed to evaluate the use of recombinant early secretory antigenic target 6 (rESAT-6), a secretory protein found only in MTB, Mycobacterium bovis, and few other mycobacterial species, as a skin marker for MTB in guinea pigs. We prepared recombinant MTB ESAT-6 and evaluated its use as a specific antigen for MTB in guinea pigs. Our results show that the purified MTB rESAT-6 antigen is capable of inducing a positive reaction only in guinea pigs sensitized to MTB. No such reaction was observed in the animals sensitized to M. bovis, BCG vaccination, or NTM (Mycobacterium avium). Our study results confirm that the ESAT-6 antigen is more specific to MTB infection than PPD and could be used in more specific skin tests for detection of MTB in large animals and in humans.

The Role of ESX-1 in Mycobacterium tuberculosis Pathogenesis.

PubMed

Wong, Ka-Wing

2017-05-01

In this article, we have described several cellular pathological effects caused by the Mycobacterium tuberculosis ESX-1. The effects include induction of necrosis, NOD2 signaling, type I interferon production, and autophagy. We then attempted to suggest that these pathological effects are mediated by the cytosolic access of M. tuberculosis -derived materials as a result of the phagosome-disrupting activity of the major ESX-1 substrate ESAT-6. Such activity of ESAT-6 is most likely due to its pore-forming activity at the membrane. The amyloidogenic characteristic of ESAT-6 is reviewed here as a potential mechanism of membrane pore formation. In addition to ESAT-6, the ESX-1 substrate EspB interferes with membrane-mediated innate immune mechanisms such as efferocytosis and autophagy, most likely through its ability to bind phospholipids. Overall, the M. tuberculosis ESX-1 secretion system appears to be a specialized system for the deployment of host membrane-targeting proteins, whose primary function is to interrupt key steps in innate immune mechanisms against pathogens. Inhibitors that block the ESX-1 system or block host factors critical for ESX-1 toxicity have been identified and should represent attractive potential new antituberculosis drugs.

Beta-ketoacyl-acyl carrier protein synthase IV: a key enzyme for regulation of medium-chain fatty acid synthesis in Cuphea lanceolata seeds.

PubMed

Schütt, Burkhardt Siegfried; Abbadi, Amine; Loddenkötter, Brigitte; Brummel, Monika; Spener, Friedrich

2002-09-01

With the aim of elucidating the mechanisms involved in the biosynthesis of medium-chain fatty acids in Cuphea lanceolata Ait., a crop accumulating up to 90% decanoic acid in seed triacylglycerols, cDNA clones of a beta-ketoacyl-acyl carrier protein (ACP) synthase IV (clKAS IV, EC 2.3.1.41) were isolated from C. lanceolata seed embryos. The amino acid sequence deduced from clKAS IV cDNA showed 80% identity to other plant KAS II-type enzymes, 55% identity towards plant KAS I and over 90% towards other Cuphea KAS IV-type sequences. Recombinant clKAS IV was functionally overexpressed in Escherichia coli, and substrate specificity of purified enzyme showed strong preference for elongation of short-chain and medium-chain acyl-ACPs (C4- to C10-ACP) with nearly equal activity. Further elongation steps were catalysed with distinctly less activity. Moreover, short- and medium-chain acyl-ACPs exerted a chain-length-specific and concentration-dependent substrate inhibition of clKAS IV. Based on these findings a regulatory mechanism for medium-chain fatty acid synthesis in C. lanceolata is presented.

Beta-ketoacyl-acyl carrier protein synthase III from pea (Pisum sativum L.): properties, inhibition by a novel thiolactomycin analogue and isolation of a cDNA clone encoding the enzyme.

PubMed

Jones, A Lesley; Gane, Andy M; Herbert, Derek; Willey, David L; Rutter, Andrew J; Kille, Peter; Dancer, Jane E; Harwood, John L

2003-03-01

A beta-ketoacyl-acyl carrier protein (ACP) synthase III (KAS III; short-chain condensing enzyme) has been partly purified from pea leaves. The enzyme, which had acetyl-CoA:ACP acyltransferase (ACAT) activity, was resolved from a second, specific, ACAT protein. The KAS III enzyme had a derived molecular mass of 42 kDa (from its cDNA sequence) and operated as a dimer. Its enzymological characteristics were similar to those of two other plant KAS III enzymes except for its inhibition by thiolactomycin. A derivative of thiolactomycin containing a longer (C8 saturated) hydrophobic side-chain (compound 332) was a more effective inhibitor of pea KAS III and showed competitive inhibition towards malonyl-ACP whereas thiolactomycin showed uncompetitive characteristics at high concentrations. This difference may be due to the better fit of compound 332 into a hydrophobic pocket at the active site. A full-length cDNA for the pea KAS III was isolated. This was expressed in Escherichia coli as a fusion protein with glutathione S-transferase in order to facilitate subsequent purification. Demonstrated activity in preparations from E. coli confirmed that the cDNA encoded a KAS III enzyme. Furthermore, the expressed KAS III had ACAT activity, showing that the latter was inherent. The derived amino acid sequence of the pea cDNA showed 81-87% similarity to that for other plant dicotyledon KAS IIIs, somewhat less for Allium porrum (leek, 71%) and for Porphyra spp. (62%), Synechocystis spp. (65%) and various bacteria (42-65%). The pea KAS III exhibited four areas of homology, three of which were around the active-site Cys(123), His(323) and Asn(353). In addition, a stretch of 23 amino acids (residues 207-229 in the pea KAS III) was almost completely conserved in the plant KAS IIIs. Modelling this stretch showed they belonged to a peptide fragment that fitted over the active site and contained segments suggested to be involved in substrate binding and in conformational changes during

Groups of adjacent contour segments for object detection.

PubMed

Ferrari, V; Fevrier, L; Jurie, F; Schmid, C

2008-01-01

We present a family of scale-invariant local shape features formed by chains of k connected, roughly straight contour segments (kAS), and their use for object class detection. kAS are able to cleanly encode pure fragments of an object boundary, without including nearby clutter. Moreover, they offer an attractive compromise between information content and repeatability, and encompass a wide variety of local shape structures. We also define a translation and scale invariant descriptor encoding the geometric configuration of the segments within a kAS, making kAS easy to reuse in other frameworks, for example as a replacement or addition to interest points. Software for detecting and describing kAS is released on lear.inrialpes.fr/software. We demonstrate the high performance of kAS within a simple but powerful sliding-window object detection scheme. Through extensive evaluations, involving eight diverse object classes and more than 1400 images, we 1) study the evolution of performance as the degree of feature complexity k varies and determine the best degree; 2) show that kAS substantially outperform interest points for detecting shape-based classes; 3) compare our object detector to the recent, state-of-the-art system by Dalal and Triggs [4].

Spectrum of antibody profiles in tuberculous elephants, cervids, and cattle.

PubMed

Lyashchenko, Konstantin P; Gortázar, Christian; Miller, Michele A; Waters, W Ray

2018-02-01

Using multi-antigen print immunoassay and DPP ® VetTB Assay approved in the United States for testing captive cervids and elephants, we analyzed antibody recognition of MPB83 and CFP10/ESAT-6 antigens in Asian elephants (Elephas maximus) infected with Mycobacterium tuberculosis and in white-tailed deer (Odocoileus virginianus), fallow deer (Dama dama), elk (Cervus elaphus), and cattle (Bos taurus) infected with Mycobacterium bovis. Serum IgG reactivity to MPB83 was found in the vast majority of tuberculous cattle and cervid species among which white-tailed deer and elk also showed significant CFP10/ESAT-6 recognition rates with added serodiagnostic value. In contrast, the infected elephants developed antibody responses mainly to CFP10/ESAT-6 with MPB83 reactivity being relatively low. The findings demonstrate distinct patterns of predominant antigen recognition by different animal hosts in tuberculosis. Copyright © 2017 Elsevier B.V. All rights reserved.

A Three-Hybrid System to Probe In Vivo Protein-Protein Interactions: Application to the Essential Proteins of the RD1 Complex of M. tuberculosis

PubMed Central

Bhalla, Kuhulika; Ghosh, Anamika; Kumar, Krishan; Kumar, Sushil; Ranganathan, Anand

2011-01-01

Background Protein-protein interactions play a crucial role in enabling a pathogen to survive within a host. In many cases the interactions involve a complex of proteins rather than just two given proteins. This is especially true for pathogens like M. tuberculosis that are able to successfully survive the inhospitable environment of the macrophage. Studying such interactions in detail may help in developing small molecules that either disrupt or augment the interactions. Here, we describe the development of an E. coli based bacterial three-hybrid system that can be used effectively to study ternary protein complexes. Methodology/Principal Findings The protein-protein interactions involved in M. tuberculosis pathogenesis have been used as a model for the validation of the three-hybrid system. Using the M. tuberculosis RD1 encoded proteins CFP10, ESAT6 and Rv3871 for our proof-of-concept studies, we show that the interaction between the proteins CFP10 and Rv3871 is strengthened and stabilized in the presence of ESAT6, the known heterodimeric partner of CFP10. Isolating peptide candidates that can disrupt crucial protein-protein interactions is another application that the system offers. We demonstrate this by using CFP10 protein as a disruptor of a previously established interaction between ESAT6 and a small peptide HCL1; at the same time we also show that CFP10 is not able to disrupt the strong interaction between ESAT6 and another peptide SL3. Conclusions/Significance The validation of the three-hybrid system paves the way for finding new peptides that are stronger binders of ESAT6 compared even to its natural partner CFP10. Additionally, we believe that the system offers an opportunity to study tri-protein complexes and also perform a screening of protein/peptide binders to known interacting proteins so as to elucidate novel tri-protein complexes. PMID:22087330

Surprisingly high specificity of the PPD skin test for M. tuberculosis infection from recent exposure in The Gambia.

PubMed

Hill, Philip C; Brookes, Roger H; Fox, Annette; Jackson-Sillah, Dolly; Lugos, Moses D; Jeffries, David J; Donkor, Simon A; Adegbola, Richard A; McAdam, Keith P W J

2006-12-20

Options for intervention against Mycobacterium tuberculosis infection are limited by the diagnostic tools available. The Purified Protein Derivative (PPD) skin test is thought to be non-specific, especially in tropical settings. We compared the PPD skin test with an ELISPOT test in The Gambia. Household contacts over six months of age of sputum smear positive TB cases and community controls were recruited. They underwent a PPD skin test and an ELISPOT test for the T cell response to PPD and ESAT-6/CFP10 antigens. Responsiveness to M. tuberculosis exposure was analysed according to sleeping proximity to an index case using logistic regression. 615 household contacts and 105 community controls were recruited. All three tests assessed increased significantly in positivity with increasing M. tuberculosis exposure, the PPD skin test most dramatically (OR 15.7; 95% CI 6.6-35.3). While the PPD skin test positivity continued to trend downwards in the community with increasing distance from a known case (61.9% to 14.3%), the PPD and ESAT-6/CFP-10 ELISPOT positivity did not. The PPD skin test was more in agreement with ESAT-6/CFP-10 ELISPOT (75%, p = 0.01) than the PPD ELISPOT (53%, p<0.0001). With increasing M. tuberculosis exposure, the proportion of ESAT-6/CFP-10 positive contacts who were PPD skin test positive increased (p<0.0001), and the proportion of ESAT-6/CFP-10 negative contacts that were PPD skin test negative decreased (p<0.0001); the converse did not occur. The PPD skin test has surprisingly high specificity for M. tuberculosis infection from recent exposure in The Gambia. In this setting, anti-tuberculous prophylaxis in PPD skin test positive individuals should be revisited.

Insights from computational analysis of full-length β-ketoacyl-[ACP] synthase-II cDNA isolated from American and African oil palms

PubMed Central

Bhore, Subhash J.; Cha, Thye S.; Amelia, Kassim; Shah, Farida H.

2014-01-01

Background: Palm oil derived from fruits (mesocarp) of African oil palm (Elaeis guineensis Jacq. Tenera) and American oil palm (E. oleifera) is important for food industry. Due to high yield, Elaeis guineensis (Tenera) is cultivated on commercial scale, though its oil contains high (~54%) level of saturated fatty acids. The rate-limiting activity of beta-ketoacyl-[ACP] synthase-II (KAS-II) is considered mainly responsible for the high (44%) level of palmitic acid (C16:0) in the oil obtained from E. guineensis. Objective: The objective of this study was to annotate KAS-II cDNA isolated from American and African oil palms. Materials and Methods: The full-length E. oleifera KAS-II (EoKAS-II) cDNA clone was isolated using random method of gene isolation. Whereas, the E. guineensis KAS-II (EgTKAS-II) cDNA was isolated using reverse transcriptase polymerase chain reaction (RT-PCR) technique; and missing ends were obtained by employing 5’and 3’ RACE technique. Results: The results show that EoKAS-II and EgTKAS-II open reading frames (ORFs) are of 1689 and 1721 bp in length, respectively. Further analysis of the both EoKAS-II and EgTKAS-II predicted protein illustrates that they contains conserved domains for ‘KAS-I and II’, ‘elongating’ condensing enzymes, ‘condensing enzymes super-family’, and ‘3-oxoacyl-[ACP] synthase II’. The predicted protein sequences shows 95% similarity with each other. Consecutively, the three active sites (Cys, His, and His) were identified in both proteins. However, difference in positions of two active Histidine (His) residues was noticed. Conclusion: These insights may serve as the foundation in understanding the variable activity of KAS-II in American and African oil palms; and cDNA clones could be useful in the genetic engineering of oil palms. PMID:24678202

A single membrane-bound enzyme catalyzes the conversion of 2,5-diketo-d-gluconate to 4-keto-d-arabonate in d-glucose oxidative fermentation by Gluconobacter oxydans NBRC 3292.

PubMed

Tazoe, Masaaki; Oishi, Hiromi; Kobayashi, Setsuko; Hoshino, Tatsuo

2016-08-01

4-Keto-d-arabonate synthase (4KAS), which converts 2,5-diketo-d-gluconate (DKGA) to 4-keto-d-arabonate (4KA) in d-glucose oxidative fermentation by some acetic acid bacteria, was solubilized from the Gluconobacter oxydans NBRC 3292 cytoplasmic membrane, and purified in an electrophoretically homogenous state. A single membrane-bound enzyme was found to catalyze the conversion from DKGA to 4KA. The 92-kDa 4KAS was a homodimeric protein not requiring O2 or a cofactor for the conversion, but was stimulated by Mn(2+). N-terminal amino acid sequencing of 4KAS, followed by gene homology search indicated a 1,197-bp open reading frame (ORF), corresponding to the GLS_c04240 locus, GenBank accession No. CP004373, encoding a 398-amino acid protein with a calculated molecular weight of 42,818 Da. An Escherichia coli transformant with the 4kas plasmid exhibited 4KAS activity. Furthermore, overexpressed recombinant 4KAS was purified in an electrophoretically homogenous state and had the same molecular size as the natural enzyme.

Overexpression of 3-Ketoacyl-Acyl-Carrier Protein Synthase IIIs in Plants Reduces the Rate of Lipid Synthesis1

PubMed Central

Dehesh, Katayoon; Tai, Heeyoung; Edwards, Patricia; Byrne, James; Jaworski, Jan G.

2001-01-01

A cDNA coding for 3-ketoacyl-acyl-carrier protein (ACP) synthase III (KAS III) from spinach (Spinacia oleracea; So KAS III) was used to isolate two closely related KAS III clones (Ch KAS III-1 and Ch KAS III-2) from Cuphea hookeriana. Both Ch KAS IIIs are expressed constitutively in all tissues examined. An increase in the levels of 16:0 was observed in tobacco (Nicotiana tabacum, WT-SR) leaves overexpressing So KAS III when under the control of the cauliflower mosaic virus-35S promoter and in Arabidopsis and rapeseed (Brassica napus) seeds overexpressing either of the Ch KAS IIIs driven by napin. These data indicate that this enzyme has a universal role in fatty acid biosynthesis, irrespective of the plant species from which it is derived or the tissue in which it is expressed. The transgenic rapeseed seeds also contained lower levels of oil as compared with the wild-type levels. In addition, the rate of lipid synthesis in transgenic rapeseed seeds was notably slower than that of the wild-type seeds. The results of the measurements of the levels of the acyl-ACP intermediates as well as any changes in levels of other fatty acid synthase enzymes suggest that malonyl-ACP, the carbon donor utilized by all the 3- ketoacyl-ACP synthases, is limiting in the transgenic plants. This further suggests that malonyl-coenzyme A is a potential limiting factor impacting the final oil content as well as further extension of 16:0. PMID:11161065

Overexpression of 3-ketoacyl-acyl-carrier protein synthase IIIs in plants reduces the rate of lipid synthesis.

PubMed

Dehesh, K; Tai, H; Edwards, P; Byrne, J; Jaworski, J G

2001-02-01

A cDNA coding for 3-ketoacyl-acyl-carrier protein (ACP) synthase III (KAS III) from spinach (Spinacia oleracea; So KAS III) was used to isolate two closely related KAS III clones (Ch KAS III-1 and Ch KAS III-2) from Cuphea hookeriana. Both Ch KAS IIIs are expressed constitutively in all tissues examined. An increase in the levels of 16:0 was observed in tobacco (Nicotiana tabacum, WT-SR) leaves overexpressing So KAS III when under the control of the cauliflower mosaic virus-35S promoter and in Arabidopsis and rapeseed (Brassica napus) seeds overexpressing either of the Ch KAS IIIs driven by napin. These data indicate that this enzyme has a universal role in fatty acid biosynthesis, irrespective of the plant species from which it is derived or the tissue in which it is expressed. The transgenic rapeseed seeds also contained lower levels of oil as compared with the wild-type levels. In addition, the rate of lipid synthesis in transgenic rapeseed seeds was notably slower than that of the wild-type seeds. The results of the measurements of the levels of the acyl-ACP intermediates as well as any changes in levels of other fatty acid synthase enzymes suggest that malonyl-ACP, the carbon donor utilized by all the 3- ketoacyl-ACP synthases, is limiting in the transgenic plants. This further suggests that malonyl-coenzyme A is a potential limiting factor impacting the final oil content as well as further extension of 16:0.

Absolute calibration technique for broadband ultrasonic transducers

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H. (Inventor)

1994-01-01

Calibrating an ultrasonic transducer can be performed with a reduced number of calculations and testing. A wide-band pulser is connected to an ultrasonic transducer under test to generate ultrasonic waves in a liquid. A single frequency is transmitted to the electrostatic acoustic transducer (ESAT) and the voltage change produced is monitored. Then a broadband ultrasonic pulse is generated by the ultrasonic transducer and received by the ESAT. The output of the ESAT is amplified and input to a digitized oscilloscope for fast Fourier transform. The resulting plot is normalized with the monitored signal from the single frequency pulse. The plot is then corrected for characteristics of the membrane and diffraction effects. The transfer function of the final plot is determined. The transfer function gives the final sensitivity of the ultrasonic transducer as a function of frequency. The advantage of the system is the speed of calibrating the transducer by a reduced number of measurements and removal of the membrane and diffraction effects.

A Cuphea beta-ketoacyl-ACP synthase shifts the synthesis of fatty acids towards shorter chains in Arabidopsis seeds expressing Cuphea FatB thioesterases.

PubMed

Leonard, J M; Knapp, S J; Slabaugh, M B

1998-03-01

Acyl-acyl carrier protein (ACP) thioesterases with specificities on medium chain substrates (C8-C14) are requisite enzymes in plants that produce 8:0, 10:0, 12:0 and 14:0 seed oils, but they may not be the sole enzymatic determinants of chain length. The contribution to chain length regulation of a beta-ketoacyl-ACP synthase, Cw KAS A1, derived from Cuphea wrightii, a species that accumulates 30% 10:0 and 54% 12:0 in seed oils, was investigated. Expression of Cw KAS A1 in Arabidopsis seeds reduced 16:0 from 8.2 to 6.2 mol%, suggesting a KAS II-type activity. In the presence of the KAS I inhibitor cerulenin, however, transgenic seed extracts extended 6:0- and 8:0-ACP at a rate four- to fivefold greater than extracts from untransformed plants, whereas no difference was observed in extension of 14:0- and 16:0-ACP. The effect of KAS A1 on seed oils was tested by combining it with the C. wrightii medium chain-specific thioesterases, Cw FatB1 and Cw FatB2, in crosses of transformed plants. Fatty acid synthesis thesis shifted towards shorter chains in progeny expressing both classes of enzymes. KasA1/FatB1 homozygotes produced threefold more 12:0 than the FatB1 parent while 14:0 and 16:0 were reduced by one-third and one-half, respectively. F2 progeny expressing KasA1 and FatB2 produced twofold more 10:0 and 1.4-fold more 12:0 than the FatB2 parent, and the double-transgenic progeny produced one-quarter less 14:0 and one-half less 16:0 than the FatB2 parent. It is hypothesized that the shift towards production of shorter chains resulted from increased pools of medium chain acyl-ACP resulting from KAS A1 activity. The combined activities of KAS A1 and FatB thioesterases appear to determine the C. wrightii phenotype.

Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

PubMed

Moguche, Albanus O; Musvosvi, Munyaradzi; Penn-Nicholson, Adam; Plumlee, Courtney R; Mearns, Helen; Geldenhuys, Hennie; Smit, Erica; Abrahams, Deborah; Rozot, Virginie; Dintwe, One; Hoff, Søren T; Kromann, Ingrid; Ruhwald, Morten; Bang, Peter; Larson, Ryan P; Shafiani, Shahin; Ma, Shuyi; Sherman, David R; Sette, Alessandro; Lindestam Arlehamn, Cecilia S; McKinney, Denise M; Maecker, Holden; Hanekom, Willem A; Hatherill, Mark; Andersen, Peter; Scriba, Thomas J; Urdahl, Kevin B

2017-06-14

CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection. Copyright © 2017 Elsevier Inc. All rights reserved.

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic Acid (C75), an Inhibitor of Fatty-acid Synthase, Suppresses the Mitochondrial Fatty Acid Synthesis Pathway and Impairs Mitochondrial Function*

PubMed Central

Chen, Cong; Han, Xiao; Zou, Xuan; Li, Yuan; Yang, Liang; Cao, Ke; Xu, Jie; Long, Jiangang; Liu, Jiankang; Feng, Zhihui

2014-01-01

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid (C75) is a synthetic fatty-acid synthase (FASN) inhibitor with potential therapeutic effects in several cancer models. Human mitochondrial β-ketoacyl-acyl carrier protein synthase (HsmtKAS) is a key enzyme in the newly discovered mitochondrial fatty acid synthesis pathway that can produce the substrate for lipoic acid (LA) synthesis. HsmtKAS shares conserved catalytic domains with FASN, which are responsible for binding to C75. In our study, we explored the possible effect of C75 on HsmtKAS and mitochondrial function. C75 treatment decreased LA content, impaired mitochondrial function, increased reactive oxygen species content, and reduced cell viability. HsmtKAS but not FASN knockdown had an effect that was similar to C75 treatment. In addition, an LA supplement efficiently inhibited C75-induced mitochondrial dysfunction and oxidative stress. Overexpression of HsmtKAS showed cellular protection against low dose C75 addition, whereas there was no protective effect upon high dose C75 addition. In summary, the mitochondrial fatty acid synthesis pathway has a vital role in mitochondrial function. Besides FASN, C75 might also inhibit HsmtKAS, thereby reducing LA production, impairing mitochondrial function, and potentially having toxic effects. LA supplements sufficiently ameliorated the toxicity of C75, showing that a combination of C75 and LA may be a reliable cancer treatment. PMID:24784139

Condensing enzymes from Cuphea wrightii associated with medium chain fatty acid biosynthesis.

PubMed

Slabaugh, M B; Leonard, J M; Knapp, S J

1998-03-01

Seed oils of most Cuphea species contain > 90% medium chain (C8-C14) fatty acids. Thioesterases with specificity for these substrates are important determinants of the medium chain phenotype. The role of condensing enzymes, however, has not been investigated. cDNA clones encoding beta-ketoacyl-acyl carrier protein (ACP) synthase (KAS) were isolated from C. wrightii, a C10/C12-producing species. Deduced amino acid sequences of four unique clones were approximately 60% identical to plant KAS I sequences and approximately 75% identical to a distinct class of KAS sequences recently identified in castor and barley. A 46 kDa protein that was observed only in developing and mature seed was detected using antiserum directed against recombinant Cuphea KAS protein. The 46 kDa protein was abundant in developing seeds of six medium chain-producing Cuphea species but barely detected in one long chain-producing species. A 48 kDa protein identified immunologically as KAS I was expressed in both medium and long chain-producing Cuphea species and was detected in all tissues tested. In in vitro assays, extracts from C. wrightii and C. viscosissima developing embryos were unable to extend fatty acid chains beyond C10 following treatment with 10 microns cerulenin, a potent inhibitor of KAS I. However, a C. viscosissima mutant, cpr-1, whose seed oils are deficient in caprate relative to wild type, was impaired in extension of C8 to C10 in this assay and Western analysis revealed a specific deficiency in 46 kDa KAS in cpr-1 embryos. These results implicate cerulenin-resistant condensing activity in production of medium chain fatty acids in Cuphea.

Effect of a multi-level education intervention model on knowledge and attitudes of accidental injuries in rural children in Zunyi, Southwest China.

PubMed

Cao, Bo-Ling; Shi, Xiu-Quan; Qi, Yong-Hong; Hui, Ya; Yang, Hua-Jun; Shi, Shang-Peng; Luo, Li-Rong; Zhang, Hong; Wang, Xin; Yang, Ying-Ping

2015-04-08

To explore the effect of a school-family-individual (SFI) multi-level education intervention model on knowledge and attitudes about accidental injuries among school-aged children to improve injury prevention strategies and reduce the incidence of pediatric injuries. The random sample of rural school-aged children were recruited by using a multistage, stratified, cluster sampling method in Zunyi, Southwest China from 2012 to 2014, and 2342 children were randomly divided into intervention and control groups. Then children answered a baseline survey to collect knowledge and attitude scores (KAS) of accidental injuries. In the intervention group, children, their parents/guardians and the school received a SFI multi-level education intervention, which included a children's injury-prevention poster at schools, an open letter about security instruction for parents/guardians and multiple-media health education (Microsoft PowerPoint lectures, videos, handbooks, etc.) to children. Children in the control group were given only handbook education. After 16 months, children answered a follow-up survey to collect data on accidental injury types and accidental injury-related KAS for comparing the intervention and control groups and baseline and follow-up data. The distribution of gender was not significantly different while age was different between the baseline and follow-up survey. At baseline, the mean KAS was lower for the intervention than control group (15.37 ± 3.40 and 18.35 ± 5.01; p < 0.001). At follow-up, the mean KAS was higher for the intervention than control group (21.16 ± 3.05 and 20.02 ± 3.40; p < 0.001). The increase in KAS in the intervention and control groups was significant (p < 0.001; KAS: 5.79 vs. 1.67) and suggested that children's injury-related KAS improved in the intervention group. Moreover, the KAS between the groups differed for most subtypes of incidental injuries (based on International Classification of Diseases 10, ICD-10) (p < 0.05). Before

Role of M Cells in Human Mucosal Immunity to Mycobacterium tuberculosis

PubMed Central

Nair, Vidhya; Khan, Haaris; Mitchell, Ron; Shiloh, Michael U

2017-01-01

Abstract Background Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is a bacterial pathogen that infects roughly one-third of the worldÕs population and causes 1–2 million deaths per year. The current paradigm is that phagocytosis of Mtb by patrolling alveolar macrophages initiates Mtb infection. While this model can account for pulmonary TB, it does not adequately explain the occurrence of extrapulmonary forms of TB that manifest in the absence of obvious lung involvement, such as tuberculous cervical lymphadenitis, also known as scrofula. We hypothesized that specialized epithelial cells called microfold cells (M cells) may be an alternate portal of entry for Mtb. Previously we demonstrated that Mtb is able to transcytose across an epithelial barrier in an M cell dependent manner and that M cell mediated transcytosis is vital for Mtb pathogenesis in a mouse model of tuberculosis. Methods We used an in vitro M-cell mediated translocation assay and a Mtb mutant lacking a key virulence factor, ESAT6. We used biochemistry and genetics to identify a novel receptor for ESAT6. We also developed a novel explanted human adenoid Mtb infection model to study mucosal immunity. Results We now demonstrate that the Mtb virulence factor ESAT6 is necessary and sufficient to mediate binding and transcytosis by M cells in vitro and in vivo, and that uptake of Mtb by M cells requires a unique cell surface ESAT6 receptor. We developed a novel explanted human adenoid model of M cell biology and demonstrate rapid Mtb transcytosis by primary human tissue within 60–120 minutes. Using flow cytometry we find that Mtb is first ingested by M cells and then after transcytosis, by tissue resident antigen-presenting cells. Explanted adenoids from 10 independent donors display a wide range of Mtb uptake. Conclusion We conclude that Mtb ESAT6 is necessary for Mtb uptake by M-cells and that binding and transcytosis require a host receptor. Because explanted

Diversion of phagosome trafficking by pathogenic Rhodococcus equi depends on mycolic acid chain length

PubMed Central

Sydor, Tobias; Bargen, Kristine; Hsu, Fong-Fu; Huth, Gitta; Holst, Otto; Wohlmann, Jens; Becken, Ulrike; Dykstra, Tobias; Söhl, Kristina; Lindner, Buko; Prescott, John F; Schaible, Ulrich E; Utermöhlen, Olaf; Haas, Albert

2013-01-01

Rhodococcus equi is a close relative of Mycobacterium spp. and a facultative intracellular pathogen which arrests phagosome maturation in macrophages before the late endocytic stage. We have screened a transposon mutant library of R. equi for mutants with decreased capability to prevent phagolysosome formation. This screen yielded a mutant in the gene for β-ketoacyl-(acyl carrier protein)-synthase A (KasA), a key enzyme of the long-chain mycolic acid synthesizing FAS-II system. The longest kasA mutant mycolic acid chains were 10 carbon units shorter than those of wild-type bacteria. Coating of non-pathogenic E. coli with purified wild-type trehalose dimycolate reduced phagolysosome formation substantially which was not the case with shorter kasA mutant-derived trehalose dimycolate. The mutant was moderately attenuated in macrophages and in a mouse infection model, but was fully cytotoxic.Whereas loss of KasA is lethal in mycobacteria, R. equi kasA mutant multiplication in broth was normal proving that long-chain mycolic acid compounds are not necessarily required for cellular integrity and viability of the bacteria that typically produce them. This study demonstrates a central role of mycolic acid chain length in diversion of trafficking by R. equi. PMID:23078612

Diversion of phagosome trafficking by pathogenic Rhodococcus equi depends on mycolic acid chain length.

PubMed

Sydor, Tobias; von Bargen, Kristine; Hsu, Fong-Fu; Huth, Gitta; Holst, Otto; Wohlmann, Jens; Becken, Ulrike; Dykstra, Tobias; Söhl, Kristina; Lindner, Buko; Prescott, John F; Schaible, Ulrich E; Utermöhlen, Olaf; Haas, Albert

2013-03-01

Rhodococcus equi is a close relative of Mycobacterium spp. and a facultative intracellular pathogen which arrests phagosome maturation in macrophages before the late endocytic stage. We have screened a transposon mutant library of R. equi for mutants with decreased capability to prevent phagolysosome formation. This screen yielded a mutant in the gene for β-ketoacyl-(acyl carrier protein)-synthase A (KasA), a key enzyme of the long-chain mycolic acid synthesizing FAS-II system. The longest kasA mutant mycolic acid chains were 10 carbon units shorter than those of wild-type bacteria. Coating of non-pathogenic E. coli with purified wild-type trehalose dimycolate reduced phagolysosome formation substantially which was not the case with shorter kasA mutant-derived trehalose dimycolate. The mutant was moderately attenuated in macrophages and in a mouse infection model, but was fully cytotoxic.Whereas loss of KasA is lethal in mycobacteria, R. equi kasA mutant multiplication in broth was normal proving that long-chain mycolic acid compounds are not necessarily required for cellular integrity and viability of the bacteria that typically produce them. This study demonstrates a central role of mycolic acid chain length in diversion of trafficking by R. equi. © 2012 Blackwell Publishing Ltd.

Friends, Depressive Symptoms, and Life Satisfaction Among Older Korean Americans.

PubMed

Roh, Soonhee; Lee, Yeon-Shim; Lee, Kyoung Hag; Shibusawa, Tazuko; Yoo, Grace J

2015-08-01

This study examined the interactive effects of social network support and depressive symptoms on life satisfaction among older Korean Americans (KAs). Using data from a sample of 200 elders in a large metropolitan area (M age = 72.50, SD = 5.15), hierarchical regression analysis was used to examine the interaction between social network support and depressive symptoms on life satisfaction among older KAs. After controlling for demographic variables, both social network support and depressive symptoms were identified as predictors for life satisfaction. Interaction effects indicated strong associations between higher social network support specifically from friends and lower depressive symptoms with higher levels of life satisfaction. Findings highlight the important role that friends play in terms of social network support for the mental health of older KAs, and the need for geriatric practitioners to monitor and assess the quality of social network support-including friendships-when working with older KAs.

The Influences of Immigration on Health Information Seeking Behaviors among Korean Americans and Native Koreans

ERIC Educational Resources Information Center

Oh, Kyeung Mi; Zhou, Qiuping; Kreps, Gary; Kim, Wonsun

2014-01-01

Korean Americans (KAs) have low screening rates for cancer and are often not well informed about their chronic diseases. Reduced access to health-related information is one reason for gaps in knowledge and the widening health disparities among minority populations. However, little research exists about KAs' health information seeking behaviors.…

Knockout of the regulatory site of 3-ketoacyl-ACP synthase III enhances short- and medium-chain acyl-ACP synthesis.

PubMed

Abbadi, A; Brummel, M; Spener, F

2000-10-01

3-ketoacyl-acyl carrier protein synthase (KAS) III catalyses the first condensing step of the fatty acid synthase (FAS) type II reaction in plants and bacteria, using acetyl CoA and malonyl-acyl carrier protein (ACP) as substrates. Enzymatic characterization of recombinant KAS III from Cuphea wrightii embryo shows that this enzyme is strongly inhibited by medium-chain acyl-ACP end products of the FAS reaction, i.e. inhibition by lauroyl-ACP was uncompetitive towards acetyl CoA and non-competitive with regard to malonyl-ACP. This indicated a distinct attachment site for regulatory acyl-ACPs. Based on alignment of primary structures of various KAS IIIs and 3-ketoacyl CoA synthases, we suspected the motif G290NTSAAS296 to be responsible for binding of regulatory acyl-ACPs. Deletion of the tetrapeptide G290NTS293 led to a change of secondary structure and complete loss of KAS III condensing activity. Exchange of asparagine291 to aspartate, alanine294 to serine and alanine295 to proline, however, produced mutant enzymes with slightly reduced condensing activity, yet with insensitivity towards acyl-ACPs. To assess the potential of unregulated KAS III as tool in oil production, we designed in vitro experiments employing FAS preparations from medium-chain fatty acid-producing Cuphea lanceolata seeds and long-chain fatty acid-producing rape seeds, each supplemented with a fivefold excess of the N291D KAS III mutant. High amounts of short-chain acyl-ACPs in the case of C. lanceolata, and of medium-chain acyl-ACPs in the case of rape seed preparations, were obtained. This approach targets regulation and offers new possibilities to derive transgenic or non-transgenic plants for production of seed oils with new qualities.

Role of apamin-sensitive small conductance calcium-activated potassium currents in long-term cardiac memory in rabbits.

PubMed

Yin, Dechun; Chen, Mu; Yang, Na; Wu, Adonis Z; Xu, Dongzhu; Tsai, Wei-Chung; Yuan, Yuan; Tian, Zhipeng; Chan, Yi-Hsin; Shen, Changyu; Chen, Zhenhui; Lin, Shien-Fong; Weiss, James N; Chen, Peng-Sheng; Everett, Thomas H

2018-05-01

Apamin-sensitive small conductance calcium-activated K current (I KAS ) is up-regulated during ventricular pacing and masks short-term cardiac memory (CM). The purpose of this study was to determine the role of I KAS in long-term CM. CM was created with 3-5 weeks of ventricular pacing and defined by a flat or inverted T wave off pacing. Epicardial optical mapping was performed in both paced and normal ventricles. Action potential duration (APD 80 ) was determined during right atrial pacing. Ventricular stability was tested before and after I KAS blockade. Four paced hearts and 4 normal hearts were used for western blotting and histology. There were no significant differences in either echocardiographic parameters or fibrosis levels between groups. Apamin induced more APD 80 prolongation in CM than in normal ventricles (mean [95% confidence interval]: 9.6% [8.8%-10.5%] vs 3.1% [1.9%-4.3%]; P <.001). Apamin significantly lengthened APD 80 in the CM model at late activation sites, indicating significant I KAS up-regulation at those sites. The CM model also had altered Ca 2+ handling, with the 50% Ca 2+ transient duration and amplitude increased at distal sites compared to a proximal site (near the pacing site). After apamin, the CM model had increased ventricular fibrillation (VF) inducibility (paced vs control: 33/40 (82.5%) vs 7/20 (35%); P <.001) and longer VF durations (124 vs 26 seconds; P <.001). Chronic ventricular pacing increases Ca 2+ transients at late activation sites, which activates I KAS to maintain repolarization reserve. I KAS blockade increases VF vulnerability in chronically paced rabbit ventricles. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Development of Solar Powered Feeding Scheme for Wireless Sensor Networks in low Solar Density Conditions / Bezvadu Sensoru Tīklu Elektroapgādes Sistēmas Izstrāde, Kas Izmanto Saules Paneļus Un Darbojas Pazeminātas Saules Radiācijas Apstākļos

NASA Astrophysics Data System (ADS)

Kondratjevs, K.; Zabasta, A.; Selmanovs-Pless, V.

2015-08-01

In the recent years, there has been significant research focus on the safety and reliability of data harvesting and optimal energy consuming by wireless sensor network nodes. If external electrical power fails, the node needs to be able to send notifications to the utility demanding the use of backup energy strategies. The authors of the research offer an approach that can help to use PV panels as an alternative power source for WSN nodes in particular irradiation conditions. Survey and testing of the main types of PV panels offered on the market in conditions closed to real ones, in which WSN nodes are maintained, have been implemented. Based on the test results, maximum power control module parameters can be calculated in order to achieve the best effectiveness of the power control system for a selected type of PV panel or panel group. The novelty of the research is an approach that includes an original test bed design for PV testing, PV testing method and selection of design and MPP control module parameters, which ensure maximum effectiveness of WSN node power feeding. Pēdējos gados vairāki pētījumi ir veltīti problēmām, kas ir saistītas ar enerģijas patēriņa mazināšanu un efektīvu izmantošanu bezvadu sensoru tīklu mezglos. Kad sensors mezgls ir izsmēlis enerģijas krājumu, tas vairs nefunkcionē un atslēdzas no kopēja tīkla, kas var būtiski ietekmēt visa tīkla veiktspēju. Šī pētījuma mērķis ir izveidot barošanas vadības moduli, lai nodrošinātu stabilu elektroapgādes spriegumu autonomi strādājošiem radio signāla atkārtotājiem, sensoriem vai vārtejām, kas darbojas bezvadu sensoru tīklos. Pētījuma ietvaros izstrādāta metode saules paneļu kvalitatīvai salīdzināšanai starp tehnoloģijām vai savā starpā, izvērtējot to atbilstību mērķa pielietojumam. Izstrādātā metode sniedz iespēju veikt kontrolētus testus pie variējošiem, simulētiem gaismas apstākļiem, ļauj prognozēt enerģijas resursus

Why do we have the kidney allocation system we have today? A history of the 2014 kidney allocation system.

PubMed

Stegall, Mark D; Stock, Peter G; Andreoni, Kenneth; Friedewald, John J; Leichtman, Alan B

2017-01-01

"Those who do not know the past are destined to repeat it". The current system for the allocation of deceased donor kidneys that was implemented in December 2014 (termed the kidney allocation system (KAS)) was the culmination of a decade-long process. Thus, many people involved in transplantation today may not be aware of the underlying concepts and early debates that resulted in KAS. Others who were involved might not remember the details (or have chosen to forget). The goal of this manuscript is to outline the history of the process in order to shed light on why KAS has its current format. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

The coordination of allocation: Logistics of kidney organ allocation to highly sensitized patients.

PubMed

Lunz, John; Hinsdale, Lisa; King, Casey; Pastush, Robin; Buenvenida, Magnolia; Harmon, Michael

2017-01-01

Since implementation, the new UNOS OPTN kidney allocation system (KAS) has drastically expanded the pool of available kidneys to candidates that may have previously waited extended periods for an organ offer. This is particularly true for highly sensitized patients. The changes to the KAS have had ramifications throughout the transplant process, including for organ procurement organizations (OPO) and local transplant hospital call centers. Here, we will examine the impact of the new KAS on the organ donation process and highlight the necessary interactions between the OPO and transplant centers to best match donor kidneys and highly sensitized recipients. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Assessing progress and outcome of early intensive behavioral intervention for toddlers with autism.

PubMed

MacDonald, Rebecca; Parry-Cruwys, Diana; Dupere, Sally; Ahearn, William

2014-12-01

Intensive behavioral intervention for young children diagnosed with autism can produce large gains in social, cognitive, and language development. Although several studies have identified behaviors that are possible indicators of best outcome, changes in performance are typically measured using norm-referenced standardized scores referencing overall functioning level rather than via repeated observational measures of autism-specific deficits (i.e., social behavior). In the current study, 83 children with autism (CWA), aged 1, 2 and 3 years, and 58 same-aged typically developing children (TDC) were directly observed in the areas of cognitive skills, joint attention (JA), play, and stereotypic behavior using a measure called the Early Skills Assessment Tool (ESAT; MacDonald et al., 2006). CWA were assessed at entry into an EIBI program and again after 1 year of treatment. Changes in performance were compared pre- and post-treatment as well as to the normative data by age. Results indicate significant gains on the ESAT across all age groups with the greatest gains seen in the children who entered treatment prior to their second birthday. Increases were seen on direct measures of JA, play, imitation and language while decreases were seen in stereotypy regardless of level of performance at entry into EIBI. The ESAT, a direct measurement tool, served as a sensitive tool to measure changes in autism symptomatology following EIBI treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reversion and conversion of Mycobacterium tuberculosis IFN-gamma ELISpot results during anti-tuberculous treatment in HIV-infected children.

PubMed

Connell, Tom G; Davies, Mary-Ann; Johannisen, Christine; Wood, Kathryn; Pienaar, Sandy; Wilkinson, Katalin A; Wilkinson, Robert J; Zar, Heather J; Beatty, David; Nicol, Mark P; Curtis, Nigel; Eley, Brian

2010-05-27

Recent interest has focused on the potential use of serial interferon gamma (IFN-gamma) release assay (IGRA) measurements to assess the response to anti-tuberculous (TB) treatment. The kinetics of IFN-gamma responses to Mycobacterium tuberculosis (MTB) antigens in HIV-infected children during treatment have not however been previously investigated. IFN-gamma responses to the MTB antigens, ESAT-6, CFP-10 and PPD were measured by an enzyme-linked immunospot assay (IFN-gamma ELISpot) at presentation and at one, two and six months after starting anti-tuberculous treatment in HIV-infected children with definite or probable TB. Responses at different time points were compared using a Mann-Whitney U test with paired data analysed using the Wilcoxon signed rank test. A Fisher's exact or Chi-squared test was used to compare proportions when test results were analysed as dichotomous outcomes. Of 102 children with suspected TB, 22 (21%) had definite TB and 24 (23%) probable TB. At least one follow up IFN-gamma ELISpot assay result was available for 31 (67%) of the 46 children. In children with definite or probable TB in whom the IFN-gamma ELISpot assay result was positive at presentation, anti-tuberculous treatment was accompanied by a significant decrease in both the magnitude of the IFN-gamma response to individual or combined MTB-specific antigens (ESAT-6 median 110 SFCs/106 PBMC (IQR 65-305) at presentation vs. 15 (10-115) at six months, p = 0.04; CFP-10 177 (48-508) vs. 20 (5-165), p = 0.004, ESAT-6 or CFP-10 median 250 SFCs/106 PBMC (IQR 94-508) vs. 25 (10-165), p = 0.004) and in the proportion of children with a positive IFN-gamma ELISpot assay (Fisher's exact test: ESAT-6 15/0 vs 5/11, p = 0.0002, CFP-10 22/0 vs 8/17, p = 0.0001, ESAT-6 or CFP-10 22/0 vs. 9/17, p= 0.002). However almost half of the children had a positive IFN-gamma ELISpot assay after six months of anti-tuberculous treatment. In addition, there was conversion of the IFN-gamma ELISpot assay result

Eruptive Keratoacanthomas Associated With Pembrolizumab Therapy

PubMed Central

Freites-Martinez, Azael; Kwong, Bernice Y.; Rieger, Kerri E.; Coit, Daniel G.; Colevas, A. Dimitrios; Lacouture, Mario E.

2017-01-01

IMPORTANCE To our knowledge, there have been no previous reports of eruptive keratoacanthomas (KAs) in patients receiving pembrolizumab. OBJECTIVE To report the cases of 3 consecutive patients with pembrolizumab-induced eruptive KAs and their management. DESIGN, SETTING, AND PARTICIPANTS Case report study of 3 patients from 2 centers with pembrolizumab-treated cancer who all developed eruptive KAs. INTERVENTIONS All 3 patients had AK treatment with clobetasol ointment and intralesional triamcinolone; 2 patients also underwent open superficial cryosurgery. RESULTS Three consecutive patients with cancer, 2 men and 1 woman (median age, 83 years; range 77–91 years), experienced pembrolizumab-associated eruptive KAs. All patients presented with a sudden onset of multiple lesions on sun-exposed areas of their extremities after a median of 13 months (range, 4–18 months) of pembrolizumab therapy. On lesional biopsy, a lichenoid infiltrate was observed in the underlying dermis, predominantly composed of CD3+ T cells, scattered CD20+ B cells, and relatively few PD-1+ (programmed cell death 1–positive) T cells, an immunophenotypic pattern also observed in other cases of anti–PD-1–induced lichenoid dermatitis. Patients were treated with clobetasol ointment and intralesional triamcinolone, alone or in combination with open superficial cryosurgery. All KAs resolved in all patients, and no new lesions occurred during close follow-up. Pembrolizumab treatment was continued without disruption in all 3 cases, and all patients had complete responses of their primary cancers. CONCLUSIONS AND RELEVANCE Pembrolizumab is used in advanced melanoma, advanced non–small-cell lung cancer, and in head and neck cancer. A variety of dermatologic immune-related adverse events including maculopapular eruption, lichenoid reactions, pruritus, and vitiligo have been described. This case series demonstrates that pembrolizumab therapy may also be associated with eruptive KAs with

Type-1 polarised dendritic cells are a potent immunogen against Mycobacterium tuberculosis.

PubMed

Satake, Y; Nakamura, Y; Kono, M; Hozumi, H; Nagata, T; Tsujimura, K; Enomoto, N; Fujisawa, T; Inui, N; Fujiyama, T; Tokura, Y; Matsui, T; Yokomura, K; Shirai, M; Hayakawa, H; Suda, T

2017-05-01

Application of immunotherapy using dendritic cells (DCs) is considered an effective treatment strategy against persistent Mycobacterium tuberculosis infection. With the goal of developing improved therapeutic vaccination strategies for patients with tuberculosis (TB), we tested the ability of ex vivo-generated DCs to induce an effective TB antigen-specific type-1 immune response. Monocyte-derived DCs from TB patients were induced to mature using a 'standard' cytokine cocktail (interleukin [IL] 1β, tumour necrosis factor alpha [TNF-α], IL-6 and prostaglandin E2) or a type 1-polarised DC (DC1) cocktail (IL-1β, TNF-α, interferon [IFN] α, IFN-γ and polyinosinic:polycytidylic acid), and were loaded with the established TB antigen 6-kDa early secretory antigenic target protein (ESAT-6). Although DC1s from TB patients expressed the same levels of multiple co-stimulatory molecules (CD83, CD86, CD80 and CD40) as the standard DCs (sDCs), DC1s secreted substantially higher levels of IL-12p70. Furthermore, when DCs pulsed with or without ESAT-6 were cultured with lymphocytes from the same patients, DC1s induced much higher numbers of ESAT-6-specific IFN-γ-producing T-cells than sDCs, as manifested by their superior induction of natural killer cell activation and antigen-independent suppression of regulatory T-cells. TB antigen-loaded DC1s are potent inducers of antigen-specific T-cells, which could be used to develop improved immunotherapies of TB.

The kidney allocation score: methodological problems, moral concerns and unintended consequences.

PubMed

Hippen, B

2009-07-01

The growing disparity between the demand for and supply of kidneys for transplantation has generated interest in alternative systems of allocating kidneys from deceased donors. This personal viewpoint focuses attention on the Kidney Allocation Score (KAS) proposal promulgated by the UNOS/OPTN Kidney Committee. I identify several methodological and moral flaws in the proposed system, concluding that any iteration of the KAS proposal should be met with more skepticism than sanguinity.

AFOSR PRET: Homeostatic & Circadian Regulation of Wakefulness During Jet Lag and Sleep Deprivation: Effect of Wake-Promoting Countermeasures

DTIC Science & Technology

2005-05-31

Behavioral Monitor 42 Samuel Rikoon Behavioral Monitor Jenna Rimberg Behavioral Monitor Elizabeth Rossin Behavioral Monitor Luz- Adriana Samper Behavioral...reviews, dissertations supported in whole or in Part by the Center 2000 (n = 2) Journal articles, chapters, reviews, dissertations Kas , M.J.H., and D.M...2001. Dinges, D.F.: Stress, fatigue, and behavioral energy. Nutrition Reviews, 59(1): S30-S32, 2001. Kas , M.J.H., and D.M. Edgar. Scheduled

Audit of Endotracheal Tube Suction in a Pediatric Intensive Care Unit.

PubMed

Davies, Kylie; Bulsara, Max K; Ramelet, Anne-Sylvie; Monterosso, Leanne

2017-02-01

We report outcomes of a clinical audit examining criteria used in clinical practice to rationalize endotracheal tube (ETT) suction, and the extent these matched criteria in the Endotracheal Suction Assessment Tool(ESAT)©. A retrospective audit of patient notes ( N = 292) and analyses of criteria documented by pediatric intensive care nurses to rationalize ETT suction were undertaken. The median number of documented respiratory and ventilation status criteria per ETT suction event that matched the ESAT© criteria was 2 [Interquartile Range (IQR) 1-6]. All criteria listed within the ESAT© were documented within the reviewed notes. A direct link was established between criteria used for current clinical practice of ETT suction and the ESAT©. The ESAT©, therefore, reflects documented clinical decision making and could be used as both a clinical and educational guide for inexperienced pediatric critical care nurses. Modification to the ESAT © requires "preparation for extubation" to be added.

The role of social support and social networks in health information-seeking behavior among Korean Americans: a qualitative study.

PubMed

Kim, Wonsun; Kreps, Gary L; Shin, Cha-Nam

2015-04-28

This study used social network theory to explore the role of social support and social networks in health information-seeking behavior among Korean American (KA) adults. A descriptive qualitative study using a web-based online survey was conducted from January 2013 to April 2013 in the U.S. The survey included open-ended questions about health information-seeking experiences in personal social networks and their importance in KA adults. Themes emerging from a constant comparative analysis of the narrative comments by 129 of the 202 respondents were analyzed. The sample consisted of 129 KA adults, 64.7% female, with a mean age of 33.2 (SD = 7.7). Friends, church members, and family members were the important network connections for KAs to obtain health information. KAs looked for a broad range of health information from social network members, from recommendations and reviews of hospitals/doctors to specific diseases or health conditions. These social networks were regarded as important for KAs because there were no language barriers, social network members had experiences similar to those of other KAs, they felt a sense of belonging with those in their networks, the network connections promoted increased understanding of different health care systems of the U.S. system, and communication with these network connections helped enhance feelings of being physically and mentally healthy. This study demonstrates the important role that social support and personal social networks perform in the dissemination of health information for a large ethnic population, KAs, who confront distinct cultural challenges when seeking health information in the U.S. Data from this study also illustrate the cultural factors that influence health information acquisition and access to social support for ethnic minorities. This study provides practical insights for professionals in health information services, namely, that social networks can be employed as a channel for disseminating

NLR mutations suppressing immune hybrid incompatibility and their effects on disease resistance.

PubMed

Atanasov, Kostadin Evgeniev; Liu, Changxin; Erban, Alexander; Kopka, Joachim; Parker, Jane E; Alcázar, Rubén

2018-05-23

Genetic divergence between populations can lead to reproductive isolation. Hybrid incompatibilities (HI) represent intermediate points along a continuum towards speciation. In plants, genetic variation in disease resistance (R) genes underlies several cases of HI. The progeny of a cross between Arabidopsis (Arabidopsis thaliana) accessions Landsberg (Ler, Poland) and Kashmir-2 (Kas-2, central Asia) exhibits immune-related HI. This incompatibility is due to a genetic interaction between a cluster of eight TNL (TOLL/INTERLEUKIN1 RECEPTOR- NUCLEOTIDE BINDING - LEUCINE RICH REPEAT) RPP1 (RECOGNITION OF PERONOSPORA PARASITICA 1)- like genes (R1- R8) from Ler and central Asian alleles of a Strubbelig-family receptor-like kinase (SRF3) from Kas-2. In characterizing mutants altered in Ler/Kas-2 HI, we mapped multiple mutations to the RPP1-like Ler locus. Analysis of these suppressor of Ler/Kas-2 incompatibility (sulki) mutants reveals complex, additive and epistatic interactions underlying RPP1-like Ler locus activity. The effects of these mutations were measured on basal defense, global gene expression, primary metabolism, and disease resistance to a local Hyaloperonospora arabidopsidis isolate (Hpa Gw) collected from Gorzów (Gw), where the Landsberg accession originated. Gene expression sectors and metabolic hallmarks identified for HI are both dependent and independent of RPP1-like Ler members. We establish that mutations suppressing immune-related Ler/Kas-2 HI do not compromise resistance to Hpa Gw. QTL mapping analysis of Hpa Gw resistance point to RPP7 as the causal locus. This work provides insight into the complex genetic architecture of the RPP1-like Ler locus and immune-related HI in Arabidopsis and into the contributions of RPP1-like genes to HI and defense. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

Reaction mechanism of recombinant 3-oxoacyl-(acyl-carrier-protein) synthase III from Cuphea wrightii embryo, a fatty acid synthase type II condensing enzyme.

PubMed

Abbadi, A; Brummel, M; Schütt, B S; Slabaugh, M B; Schuch, R; Spener, F

2000-01-01

A unique feature of fatty acid synthase (FAS) type II of higher plants and bacteria is 3-oxoacyl-[acyl-carrier-protein (ACP)] synthase III (KAS III), which catalyses the committing condensing reaction. Working with KAS IIIs from Cuphea seeds we obtained kinetic evidence that KAS III catalysis follows a Ping-Pong mechanism and that these enzymes have substrate-binding sites for acetyl-CoA and malonyl-ACP. It was the aim of the present study to identify these binding sites and to elucidate the catalytic mechanism of recombinant Cuphea wrightii KAS III, which we expressed in Escherichia coli. We engineered mutants, which allowed us to dissect the condensing reaction into three stages, i.e. formation of acyl-enzyme, decarboxylation of malonyl-ACP, and final Claisen condensation. Incubation of recombinant enzyme with [1-(14)C]acetyl-CoA-labelled Cys(111), and the replacement of this residue by Ala and Ser resulted in loss of overall condensing activity. The Cys(111)Ser mutant, however, still was able to bind acetyl-CoA and to catalyse subsequent binding and decarboxylation of malonyl-ACP to acetyl-ACP. We replaced His(261) with Ala and Arg and found that the former lost activity, whereas the latter retained overall condensing activity, which indicated a general-base action of His(261). Double mutants Cys(111)Ser/His(261)Ala and Cys(111)Ser/His(261)Arg were not able to catalyse overall condensation, but the double mutant containing Arg induced decarboxylation of [2-(14)C]malonyl-ACP, a reaction indicating the role of His(261) in general-acid catalysis. Finally, alanine scanning revealed the involvement of Arg(150) and Arg(306) in KAS III catalysis. The results offer for the first time a detailed mechanism for a condensing reaction catalysed by a FAS type II condensing enzyme.

Reaction mechanism of recombinant 3-oxoacyl-(acyl-carrier-protein) synthase III from Cuphea wrightii embryo, a fatty acid synthase type II condensing enzyme.

PubMed Central

Abbadi, A; Brummel, M; Schütt, B S; Slabaugh, M B; Schuch, R; Spener, F

2000-01-01

A unique feature of fatty acid synthase (FAS) type II of higher plants and bacteria is 3-oxoacyl-[acyl-carrier-protein (ACP)] synthase III (KAS III), which catalyses the committing condensing reaction. Working with KAS IIIs from Cuphea seeds we obtained kinetic evidence that KAS III catalysis follows a Ping-Pong mechanism and that these enzymes have substrate-binding sites for acetyl-CoA and malonyl-ACP. It was the aim of the present study to identify these binding sites and to elucidate the catalytic mechanism of recombinant Cuphea wrightii KAS III, which we expressed in Escherichia coli. We engineered mutants, which allowed us to dissect the condensing reaction into three stages, i.e. formation of acyl-enzyme, decarboxylation of malonyl-ACP, and final Claisen condensation. Incubation of recombinant enzyme with [1-(14)C]acetyl-CoA-labelled Cys(111), and the replacement of this residue by Ala and Ser resulted in loss of overall condensing activity. The Cys(111)Ser mutant, however, still was able to bind acetyl-CoA and to catalyse subsequent binding and decarboxylation of malonyl-ACP to acetyl-ACP. We replaced His(261) with Ala and Arg and found that the former lost activity, whereas the latter retained overall condensing activity, which indicated a general-base action of His(261). Double mutants Cys(111)Ser/His(261)Ala and Cys(111)Ser/His(261)Arg were not able to catalyse overall condensation, but the double mutant containing Arg induced decarboxylation of [2-(14)C]malonyl-ACP, a reaction indicating the role of His(261) in general-acid catalysis. Finally, alanine scanning revealed the involvement of Arg(150) and Arg(306) in KAS III catalysis. The results offer for the first time a detailed mechanism for a condensing reaction catalysed by a FAS type II condensing enzyme. PMID:10600651

Clinico-morphological features of BRAF inhibition-induced proliferative skin lesions in cancer patients.

PubMed

Belum, Viswanath Reddy; Rosen, Alyx C; Jaimes, Natalia; Dranitsaris, George; Pulitzer, Melissa P; Busam, Klaus J; Marghoob, Ashfaq A; Carvajal, Richard D; Chapman, Paul B; Lacouture, Mario E

2015-01-01

The use of BRAF inhibitors may lead to the development of cutaneous toxicities such as rashes, photosensitivity, alopecia, palmoplantar erythrodysesthesia, and proliferative skin lesions, including keratoacanthomas (KAs) and cutaneous squamous cell carcinomas (cuSCCs). The latter are noteworthy for their potential to exhibit malignant features, and they may necessitate invasive treatment. Their prompt identification is of primary importance for directing supportive care efforts and maintaining dose intensity while minimizing the morbidity associated with supportive care interventions. Because such lesions are less familiar to oncologists, this study was designed to characterize their clinico-morphological features, which have not been hitherto described. The clinical and dermoscopic characteristics and risk factors of new-onset proliferative skin lesions (benign verrucous lesions and KAs/cuSCCs) developing after the initiation of treatment with vemurafenib, dabrafenib, and XL281 were analyzed; the histopathological diagnoses were ascertained. The majority of the lesions were benign verrucous lesions (78%, n = 87), whereas KAs/cuSCCs represented 22% (n = 25). The median times to biopsy for the initial verrucous lesions and KAs/cuSCCs were 4.8 and 10.5 weeks, respectively. The clinico-morphological features significant for KAs/cuSCCs included a larger size (P < .001), a nodular appearance (P < .001), a central keratin plug (P < .001), a central ulceration or crust (P = .04), an adherent scale (P = .02), an erythematous halo (P = .03), and a scaly ring (collarette; P < .001) at the periphery. Our findings represent the first detailed description of the clinico-morphological characteristics that permit distinction between the benign and malignant skin lesions induced by BRAF inhibitors. They are valuable for the recognition of lesions that require intervention and/or a dermatology referral versus those that permit provisional

Colorectal Cancer Screening among Korean Americans in Chicago: Does It Matter Whether They had the Screening in Korea or the US?

PubMed

Lee, Shin Young

2018-05-26

Background: Colorectal cancer (CRC) is one of the most common cancers in Korean Americans (KAs) and CRC screening can detect CRC early and may reduce the incidence of CRC by leading to removal of precancerous polyps. Many KAs in the US leave the country, primarily to travel to Korea, for health screening. The aim of this study was to (a) assess CRC screening rates, including fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy and (b) explore factors related to these tests among KAs by location of CRC screening. Methods: Descriptive and correlational research design with cross-sectional surveys was used with 210 KAs. Socio-demographics (age, gender, years in the US, marital status, education, employment, household income, and proficiency in spoken English), access to health care (health insurance and usual source of health care), and location of CRC screening utilization (Korea, the US, or both Korea and US) were measured and analyzed using descriptive statistics and multinominal logistic regression. Results: Out of 133 KA participants who had had lifetime CRC screening (i.e., had ever had FOBT, flexible sigmoidoscopy, or colonoscopy), 19% had visited Korea and undergone CRC screening in their lifetimes. Among socio-demographic factors and access to health care factors, having a usual source of health care in the US (OR=8.45) was significantly associated with having undergone lifetime CRC screening in the US. Having health insurance in the US and having had lifetime CRC screening in the US were marginally significant (OR=2.54). Conclusion: Access to health care in the US is important for KAs to have CRC screening in the US. As medical tourism has been increasing globally, the location of CRC screening utilization must be considered in research on cancer screening to determine correlates of CRC screening.

Correlates of hepatitis B virus health-related behaviors of Korean Americans: a situation-specific nursing theory.

PubMed

Lee, Haeok; Fawcett, Jacqueline; Yang, Jin Hyang; Hann, Hie-Won

2012-12-01

The purpose of this article is to explain the evolution of a situation-specific theory developed to enhance understanding of health-related behaviors of Korean Americans (KAs) who have or are at risk for a chronic hepatitis B virus (HBV) infection. The situation-specific theory evolved from an integration of the Network Episode Model, studies of health-related behaviors of people with HBV infection, and our studies of and practice experiences with Asian American individuals with HBV infection. The major concepts of the theory are sociocultural context, social network, individual-level factors, illness experience, and health-related behaviors. The major propositions of the theory are that sociocultural context, social network, and individual-level factors influence the illness experience, and that sociocultural context, social network, individual-level factors, and the illness experience influence health-related behaviors of KAs who have or are at risk for HBV infection. This situation-specific theory represents a translation of abstract concepts into clinical reality. The theory is an explanation of correlates of health-related HBV behaviors of KAs. The next step is to develop and test the effectiveness of a nursing intervention designed to promote behaviors that will enhance the health of KAs who have or are at risk for HBV infection, and that takes into account sociocultural context, social network, individual-level factors, and illness experience. © 2012 Sigma Theta Tau International.

Synthesis, molecular modeling and biological evaluation of PSB as targeted antibiotics.

PubMed

Cheng, Kui; Zheng, Qing-Zhong; Hou, Jin; Zhou, Yang; Liu, Chang-Hong; Zhao, Jing; Zhu, Hai-Liang

2010-04-01

We described here the design, synthesis, molecular modeling, and biological evaluation of a series of peptide and Schiff bases (PSB) small molecules, inhibitors of Escherichia coli beta-Ketoacyl-acyl carrier protein synthase III (ecKAS III). The initial lead compound was reported by us previously, we continued to carry out structure-activity relationship studies and optimize the lead structure to potent inhibitors in this research. The results demonstrated that both N-(2-(3,5-dichloro-2-hydroxybenzylideneamino)propyl)-2-hydroxybenzamide (1f) and 2-hydroxy-N-(2-(2-hydroxy-5-iodobenzylideneamino)propyl)-4-methylbenzamide (3e) posses good ecKAS III inhibitory activity and well binding affinities by bonding Gly152/Gly209 of ecKAS III and fit into the mouth of the substrate tunnel, and can be as potential antibiotics agent, displaying minimal inhibitory concentration values in the range 0.20-3.13microg/mL and 0.39-3.13microg/mL against various bacteria. Copyright 2010 Elsevier Ltd. All rights reserved.

Transgenic carrot expressing fusion protein comprising M. tuberculosis antigens induces immune response in mice.

PubMed

Permyakova, Natalia V; Zagorskaya, Alla A; Belavin, Pavel A; Uvarova, Elena A; Nosareva, Olesya V; Nesterov, Andrey E; Novikovskaya, Anna A; Zav'yalov, Evgeniy L; Moshkin, Mikhail P; Deineko, Elena V

2015-01-01

Tuberculosis remains one of the major infectious diseases, which continues to pose a major global health problem. Transgenic plants may serve as bioreactors to produce heterologous proteins including antibodies, antigens, and hormones. In the present study, a genetic construct has been designed that comprises the Mycobacterium tuberculosis genes cfp10, esat6 and dIFN gene, which encode deltaferon, a recombinant analog of the human γ-interferon designed for expression in plant tissues. This construct was transferred to the carrot (Daucus carota L.) genome by Agrobacterium-mediated transformation. This study demonstrates that the fusion protein CFP10-ESAT6-dIFN is synthesized in the transgenic carrot storage roots. The protein is able to induce both humoral and cell-mediated immune responses in laboratory animals (mice) when administered either orally or by injection. It should be emphasized that M. tuberculosis antigens contained in the fusion protein have no cytotoxic effect on peripheral blood mononuclear cells.

Targeted Delivery of Carbon Nanotubes to Cancer Cells

DTIC Science & Technology

2009-09-01

Taylor S, Li HP, Fernando KAS, Qu LW, Wang W, Gu LR, Zhou B, Sun YP. Advances toward bioapplications of carbon nanotubes. J Mater Chem. 14: 527...respectively. For car- boxylated-CNTs and RFB4-coupled CNTs, 20 ll of the dispersion was spun cast on to freshly cleaved mica at 3500 rpm for 30 sec...Lin Y, Taylor S, Li HP, Fernando KAS, Qu LW, Wang W, Gu LR, Zhou B, Sun YP. Advances toward bioapplications of carbon nano- tubes. J Mater Chem

Measuring and monitoring equity in access to deceased donor kidney transplantation.

PubMed

Stewart, D E; Wilk, A R; Toll, A E; Harper, A M; Lehman, R R; Robinson, A M; Noreen, S A; Edwards, E B; Klassen, D K

2018-05-07

The Organ Procurement and Transplantation Network monitors progress toward strategic goals such as increasing the number of transplants and improving waitlisted patient, living donor, and transplant recipient outcomes. However, a methodology for assessing system performance in providing equity in access to transplants was lacking. We present a novel approach for quantifying the degree of disparity in access to deceased donor kidney transplants among waitlisted patients and determine which factors are most associated with disparities. A Poisson rate regression model was built for each of 29 quarterly, period-prevalent cohorts (January 1, 2010-March 31, 2017; 5 years pre-kidney allocation system [KAS], 2 years post-KAS) of active kidney waiting list registrations. Inequity was quantified as the outlier-robust standard deviation (SD w ) of predicted transplant rates (log scale) among registrations, after "discounting" for intentional, policy-induced disparities (eg, pediatric priority) by holding such factors constant. The overall SD w declined by 40% after KAS implementation, suggesting substantially increased equity. Risk-adjusted, factor-specific disparities were measured with the SD w after holding all other factors constant. Disparities associated with calculated panel-reactive antibodies decreased sharply. Donor service area was the factor most associated with access disparities post-KAS. This methodology will help the transplant community evaluate tradeoffs between equity and utility-centric goals when considering new policies and help monitor equity in access as policies change. © 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.

Electrostatics of cysteine residues in proteins: Parameterization and validation of a simple model

PubMed Central

Salsbury, Freddie R.; Poole, Leslie B.; Fetrow, Jacquelyn S.

2013-01-01

One of the most popular and simple models for the calculation of pKas from a protein structure is the semi-macroscopic electrostatic model MEAD. This model requires empirical parameters for each residue to calculate pKas. Analysis of current, widely used empirical parameters for cysteine residues showed that they did not reproduce expected cysteine pKas; thus, we set out to identify parameters consistent with the CHARMM27 force field that capture both the behavior of typical cysteines in proteins and the behavior of cysteines which have perturbed pKas. The new parameters were validated in three ways: (1) calculation across a large set of typical cysteines in proteins (where the calculations are expected to reproduce expected ensemble behavior); (2) calculation across a set of perturbed cysteines in proteins (where the calculations are expected to reproduce the shifted ensemble behavior); and (3) comparison to experimentally determined pKa values (where the calculation should reproduce the pKa within experimental error). Both the general behavior of cysteines in proteins and the perturbed pKa in some proteins can be predicted reasonably well using the newly determined empirical parameters within the MEAD model for protein electrostatics. This study provides the first general analysis of the electrostatics of cysteines in proteins, with specific attention paid to capturing both the behavior of typical cysteines in a protein and the behavior of cysteines whose pKa should be shifted, and validation of force field parameters for cysteine residues. PMID:22777874

Knowledge and abilities catalog for nuclear power plant operators: Boiling water reactors, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-08-01

The Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Boiling-Water Reactors (BWRs) (NUREG-1123, Revision 1) provides the basis for the development of content-valid licensing examinations for reactor operators (ROs) and senior reactor operators (SROs). The examinations developed using the BWR Catalog along with the Operator Licensing Examiner Standards (NUREG-1021) and the Examiner`s Handbook for Developing Operator Licensing Written Examinations (NUREG/BR-0122), will cover the topics listed under Title 10, Code of Federal Regulations, Part 55 (10 CFR 55). The BWR Catalog contains approximately 7,000 knowledge and ability (K/A) statements for ROs and SROs at BWRs. The catalog is organized intomore » six major sections: Organization of the Catalog, Generic Knowledge and Ability Statements, Plant Systems grouped by Safety Functions, Emergency and Abnormal Plant Evolutions, Components, and Theory. Revision 1 to the BWR Catalog represents a modification in form and content of the original catalog. The K/As were linked to their applicable 10 CFR 55 item numbers. SRO level K/As were identified by 10 CFR 55.43 item numbers. The plant-wide generic and system generic K/As were combined in one section with approximately one hundred new K/As. Component Cooling Water and Instrument Air Systems were added to the Systems Section. Finally, High Containment Hydrogen Concentration and Plant Fire On Site evolutions added to the Emergency and Abnormal Plant Evolutions section.« less

An arsenate-reducing and alkane-metabolizing novel bacterium, Rhizobium arsenicireducens sp. nov., isolated from arsenic-rich groundwater.

PubMed

Mohapatra, Balaram; Sarkar, Angana; Joshi, Swati; Chatterjee, Atrayee; Kazy, Sufia Khannam; Maiti, Mrinal Kumar; Satyanarayana, Tulasi; Sar, Pinaki

2017-03-01

A novel arsenic (As)-resistant, arsenate-respiring, alkane-metabolizing bacterium KAs 5-22 T , isolated from As-rich groundwater of West Bengal was characterized by physiological and genomic properties. Cells of strain KAs 5-22 T were Gram-stain-negative, rod-shaped, motile, and facultative anaerobic. Growth occurred at optimum of pH 6.0-7.0, temperature 30 °C. 16S rRNA gene affiliated the strain KAs 5-22 T to the genus Rhizobium showing maximum similarity (98.4 %) with the type strain of Rhizobium naphthalenivorans TSY03b T followed by (98.0 % similarity) Rhizobium selenitireducens B1 T . The genomic G + C content was 59.4 mol%, and DNA-DNA relatedness with its closest phylogenetic neighbors was 50.2 %. Chemotaxonomy indicated UQ-10 as the major quinone; phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol as major polar lipids; C 16:0 , C 17:0 , 2-OH C 10:0 , 3-OH C 16:0 , and unresolved C 18:1 ɷ7C/ɷ9C as predominant fatty acids. The cells were found to reduce O 2 , As 5+ , NO 3 - , SO 4 2- and Fe 3+ as alternate electron acceptors. The strain's ability to metabolize dodecane or other alkanes as sole carbon source using As 5+ as terminal electron acceptor was supported by the presence of genes encoding benzyl succinate synthase (bssA like) and molybdopterin-binding site (mopB) of As 5+ respiratory reductase (arrA). Differential phenotypic, chemotaxonomic, genotypic as well as physiological properties revealed that the strain KAs 5-22 T is separated from its nearest recognized Rhizobium species. On the basis of the data presented, strain KAs 5-22 T is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium arsenicireducens sp. nov. is proposed as type strain (=LMG 28795 T =MTCC 12115 T ).

[How can rehabilitation and the psychiatric sector complement each other?].

PubMed

Dandoy, Stéphanie

2014-01-01

The specific experience of the ESAT in Aubervilliers enables us to measure the benefit which a real partnership between the medico-social team and the area psychiatric team could have. This complementary approach favours a topological separation between a place of support and a place of work and facilitates the individual's personal reconstruction.

Metagenomic Analysis of the Sponge Discodermia Reveals the Production of the Cyanobacterial Natural Product Kasumigamide by 'Entotheonella'.

PubMed

Nakashima, Yu; Egami, Yoko; Kimura, Miki; Wakimoto, Toshiyuki; Abe, Ikuro

2016-01-01

Sponge metagenomes are a useful platform to mine cryptic biosynthetic gene clusters responsible for production of natural products involved in the sponge-microbe association. Since numerous sponge-derived bioactive metabolites are biosynthesized by the symbiotic bacteria, this strategy may concurrently reveal sponge-symbiont produced compounds. Accordingly, a metagenomic analysis of the Japanese marine sponge Discodermia calyx has resulted in the identification of a hybrid type I polyketide synthase-nonribosomal peptide synthetase gene (kas). Bioinformatic analysis of the gene product suggested its involvement in the biosynthesis of kasumigamide, a tetrapeptide originally isolated from freshwater free-living cyanobacterium Microcystis aeruginosa NIES-87. Subsequent investigation of the sponge metabolic profile revealed the presence of kasumigamide in the sponge extract. The kasumigamide producing bacterium was identified as an 'Entotheonella' sp. Moreover, an in silico analysis of kas gene homologs uncovered the presence of kas family genes in two additional bacteria from different phyla. The production of kasumigamide by distantly related multiple bacterial strains implicates horizontal gene transfer and raises the potential for a wider distribution across other bacterial groups.

Carbonic anhydrase activators: activation of the archaeal beta-class (Cab) and gamma-class (Cam) carbonic anhydrases with amino acids and amines.

PubMed

Innocenti, Alessio; Zimmerman, Sabrina A; Scozzafava, Andrea; Ferry, James G; Supuran, Claudiu T

2008-12-01

Activation of the archaeal beta-class (Cab) and gamma-class (Cam) carbonic anhydrases (CAs, EC 4.2.1.1) with a series of natural and non-natural amino acids and aromatic/heterocyclic amines has been investigated. Cab, Zn-Cam and Co-Cam showed an activation profile with natural, L- and D-amino acids very different of those of the alpha-class enzymes CA I, II and III. Most of these compounds showed medium efficacy as archaeal CA activators, except for D-Phe and L-Tyr which were effective Cab activators (K(A)s of 10.3-10.5 microM), 2-pyridylmethylamine and 1-(2-aminoethyl)-piperazine which effectively activated Zn-Cam (K(A)s of 10.1-11.4 microM) and serotonin, L-adrenaline and 2-pyridylmethylamine which were the best Co-Cam activators (K(A)s of 0.97-8.9 microM). We prove here that the activation mechanisms of the alpha-, beta-, and gamma-class CAs are similar, although the activation profiles with various compounds differ dramatically between these diverse enzymes.

Acidity of edge surface sites of montmorillonite and kaolinite

NASA Astrophysics Data System (ADS)

Liu, Xiandong; Lu, Xiancai; Sprik, Michiel; Cheng, Jun; Meijer, Evert Jan; Wang, Rucheng

2013-09-01

Acid-base chemistry of clay minerals is central to their interfacial properties, but up to now a quantitative understanding on the surface acidity is still lacking. In this study, with first principles molecular dynamics (FPMD) based vertical energy gap technique, we calculate the acidity constants of surface groups on (0 1 0)-type edges of montmorillonite and kaolinite, which are representatives of 2:1 and 1:1-type clay minerals, respectively. It shows that tbnd Si-OH and tbnd Al-OH2OH groups of kaolinite have pKas of 6.9 and 5.7 and those of montmorillonite have pKas of 7.0 and 8.3, respectively. For each mineral, the calculated pKas are consistent with the experimental ranges derived from fittings of titration curves, indicating that tbnd Si-OH and tbnd Al-OH2OH groups are the major acidic sites responsible to pH-dependent experimental observations. The effect of Mg substitution in montmorillonite is investigated and it is found that Mg substitution increases the pKas of the neighboring tbnd Si-OH and tbnd Si-OH2 groups by 2-3 pKa units. Furthermore, our calculation shows that the pKa of edge tbnd Mg-(OH2)2 is as high as 13.2, indicating the protonated state dominates under common pH. Together with previous adsorption experiments, our derived acidity constants suggest that tbnd Si-O- and tbnd Al-(OH)2 groups are the most probable edge sites for complexing heavy metal cations.

Multi-Object Filtering for Space Situational Awareness

DTIC Science & Technology

2014-06-01

labelling such as the labelled multi- Bernoulli filter [27]. 3.2 Filter derivation: key modelling assumptions Ouf of the general filtering framework [14...radiation pressure in the canon- ball model has been taken into account, leading to the following acceleration: arad = −Fp · C A m E c AEarth |r− rSun| esatSun

Effect of skin test on serum antibody responses to Mycobacterium bovis infection in cattle

USDA-ARS?s Scientific Manuscript database

Recently, several serologic tests designed to detect immunodominant antibodies to M. bovis antigens (e.g., MPB83, MPB70, ESAT-6, and CFP10) have emerged for potential use with samples from cattle. Of these, a commercial ELISA to MPB83/MPB70 (M. bovis antibody ELISA) has gained approval for use in ca...

Exosomes derived from tumor cells genetically modified to express Mycobacterium tuberculosis antigen: a novel vaccine for cancer therapy.

PubMed

Koyama, Yoshiyuki; Ito, Tomoko; Hasegawa, Aya; Eriguchi, Masazumi; Inaba, Toshio; Ushigusa, Takahiro; Sugiura, Kikuya

2016-11-01

To examine the potential of exosomes derived from the tumor cells, which had been genetically modified to express a Mycobacterium tuberculosis antigen, as a cancer vaccine aimed at overcoming the weak immunogenicity of tumor antigens. We transfected B16 melanoma cells with a plasmid encoding the M. tuberculosis antigen, early secretory antigenic target-6 (ESAT-6). The secreted exosomes bearing both tumor-associated antigens and the pathogenic antigen (or their epitopes) were collected. When the exosomes were injected into foot pads of mice, they significantly (p < 0.05) evoked cellular immunity against both ESAT-6, and B16 tumor cells. Intra-tumoral injection of the exosomes significantly suppressed (p < 0.001) tumor growth in syngeneic B16 tumor-bearing mice, while the exosomes derived from the non-transfected B16 cells showed no effect on tumor growth, although both exosomes should have similar tumor antigens. Exosomes bearing both tumor antigens and the M. tuberculosis antigen (or their epitopes) have a high potential as a candidate for cancer vaccine to overcome the immune escape by tumor cells.

Thermal stability of self-assembled peptide vaccine materials.

PubMed

Sun, Tao; Han, Huifang; Hudalla, Gregory A; Wen, Yi; Pompano, Rebecca R; Collier, Joel H

2016-01-01

The majority of current vaccines depend on a continuous "cold chain" of storage and handling between 2 and 8°C. Vaccines experiencing temperature excursions outside this range can suffer from reduced potency. This thermal sensitivity results in significant losses of vaccine material each year and risks the administration of vaccines with diminished protective ability, issues that are heightened in the developing world. Here, using peptide self-assemblies based on the fibril-forming peptide Q11 and containing the epitopes OVA323-339 from ovalbumin or ESAT651-70 from Mycobacterium tuberculosis, the chemical, conformational, and immunological stability of supramolecular peptide materials were investigated. It was expected that these materials would exhibit advantageous thermal stability owing to their adjuvant-free and fully synthetic construction. Neither chemical nor conformational changes were observed for either peptide when stored at 45°C for 7days. ESAT651-70-Q11 was strongly immunogenic whether it was stored as a dry powder or as aqueous nanofibers, showing undiminished immunogenicity even when stored as long as six months at 45°C. This result was in contrast to ESAT651-70 conjugated to a protein carrier and adjuvanted with alum, which demonstrated marked thermal sensitivity in these conditions. Antibody titers and affinities were undiminished in mice for OVA323-339-Q11 if it was stored as assembled nanofibers, yet some diminishment was observed for material stored as a dry powder. The OVA study was done in a different mouse strain and with a different prime/boost regimen, and so it should not be compared directly with the study for the ESAT epitope. This work indicates that peptide self-assemblies can possess attractive thermal stability properties in the context of vaccine development. Almost all current vaccines must be maintained within a tight and refrigerated temperature range, usually between 2 and 8°C. This presents significant challenges for their

Geomorphology and age of the Marocche di Dro rock avalanches (Trentino, Italy)

NASA Astrophysics Data System (ADS)

Ivy-Ochs, S.; Martin, S.; Campedel, P.; Hippe, K.; Alfimov, V.; Vockenhuber, C.; Andreotti, E.; Carugati, G.; Pasqual, D.; Rigo, M.; Viganò, A.

2017-08-01

The Marocche di Dro deposits in the lower Sarca Valley are some of the most distinctive rock avalanche deposits of the Alps. We use geomorphology and cosmogenic 36Cl exposure dating of boulders to divide the Marocche di Dro deposits into two rock avalanche bodies; the Marocca Principale to the north and the Kas to the south. The deposits were previously undated and had been mapped as up to five different events. The largest event Marocca Principale, which comprises an estimated 1000 106 m3 of predominantly Rotzo Formation limestones, occurred 5300 ± 860 yr ago. The release area is located mainly in the alcove between Mt. Casale and Mt. Granzoline, but likely extends all the way to Mt. Brento. The Kas event took place 1080 ± 160 yr ago with detachment below Mt. Brento. The Kas debris, with an estimated volume of 300 106 m3, buried the southern third of the Marocca Principale deposit. Kas presents a barren, stark landscape dominated by house-sized Tovel Member Rotzo Formation boulders bearing distinctive chert lenses. Both the extreme relief of the rock wall (more than 1300 m) and the tectonic setting predispose the range front to massive failure. For the two events, initially translational movement likely quickly evolved into complex failure and massive collapse. Run-out across the valley of several kilometers and run-up on the opposite slope of hundreds of meters followed. A summary of all dated and large historical landslides in the Alps underlines the periods of enhanced slope activity discussed in the literature: 10-9 kyr, 5-3 kyr, and 2-1 kyr, the latter especially for the Southern Alps. No deposits of the first temporal cluster are found at Marocche di Dro. The age of Marocca Principale at 5300 ± 860 yr suggests occurrence during the second period. Failure may have been related to the shift to wetter, colder climate at the transition from the middle to the late Holocene. Nevertheless, a seismic trigger cannot be ruled out. For the Kas rock avalanche at 1080

Improved training tolerance by supplementation with α-Keto acids in untrained young adults: a randomized, double blind, placebo-controlled trial

PubMed Central

2012-01-01

Background Exercise causes a variety of physiological and metabolic changes that can in turn reduce exercise tolerance. One of the potential mechanisms responsible for fatigue is “exercise-induced hyperammonemia”. Previous studies have shown that supplementation with amino acids can increase training tolerance. The α-keto acids are biochemical analogs of amino acids and can be converted to amino acids through transamination, thus reducing the cellular ammonia level. This double blind, placebo-controlled study was designed to investigate the effects of α-keto acid supplementation (KAS) on training tolerance, training effect, and stress-recovery state. Methods Thirty-three untrained young male adults underwent four weeks of training (5 sessions/week; 30 minutes running at the individual anaerobic threshold followed by 3 x 3 minute sprints/each session). Throughout the 4 weeks of training and one week of recovery, subjects took α-ketoglutarate (AKG group, 0.2 g/kg/d, n = 9), branched-chain keto acids (BCKA group, 0.2 g/kg/d, n = 12) or isocaloric placebo (control group, n = 12) daily. Results The 4th week training volume, maximum power output and muscle torque were higher in the AKG group (175 ± 42 min, 412 ± 49 Watts and 293 ± 58 Newton meters, respectively, P<0.05) and the BCKA group (158 ± 35, 390 ± 29 and 273 ± 47, P<0.05) than in the control group (92 ± 70, 381 ± 67 and 233 ± 43). The general stress and emotional exhaustion as assessed by the rest-stress-questionnaire-sport after the 3rd week of training increased significantly in the control group (P<0.05), but not in the KAS groups. Conclusions Under KAS, subjects could bear a higher training volume and reach a higher power output and peak muscle torque, accompanied by a better stress-recovery-state. Thus, KAS improves exercise tolerance and training effects along with a better stress-recovery state. Whether the improved training tolerance

Comparative analysis of complete orthologous centromeres from two subspecies of rice reveals rapid variation of centromere organization and structure.

PubMed

Wu, Jianzhong; Fujisawa, Masaki; Tian, Zhixi; Yamagata, Harumi; Kamiya, Kozue; Shibata, Michie; Hosokawa, Satomi; Ito, Yukiyo; Hamada, Masao; Katagiri, Satoshi; Kurita, Kanako; Yamamoto, Mayu; Kikuta, Ari; Machita, Kayo; Karasawa, Wataru; Kanamori, Hiroyuki; Namiki, Nobukazu; Mizuno, Hiroshi; Ma, Jianxin; Sasaki, Takuji; Matsumoto, Takashi

2009-12-01

Centromeres are sites for assembly of the chromosomal structures that mediate faithful segregation at mitosis and meiosis. This function is conserved across species, but the DNA components that are involved in kinetochore formation differ greatly, even between closely related species. To shed light on the nature, evolutionary timing and evolutionary dynamics of rice centromeres, we decoded a 2.25-Mb DNA sequence covering the centromeric region of chromosome 8 of an indica rice variety, 'Kasalath' (Kas-Cen8). Analysis of repetitive sequences in Kas-Cen8 led to the identification of 222 long terminal repeat (LTR)-retrotransposon elements and 584 CentO satellite monomers, which account for 59.2% of the region. A comparison of the Kas-Cen8 sequence with that of japonica rice 'Nipponbare' (Nip-Cen8) revealed that about 66.8% of the Kas-Cen8 sequence was collinear with that of Nip-Cen8. Although the 27 putative genes are conserved between the two subspecies, only 55.4% of the total LTR-retrotransposon elements in 'Kasalath' had orthologs in 'Nipponbare', thus reflecting recent proliferation of a considerable number of LTR-retrotransposons since the divergence of two rice subspecies of indica and japonica within Oryza sativa. Comparative analysis of the subfamilies, time of insertion, and organization patterns of inserted LTR-retrotransposons between the two Cen8 regions revealed variations between 'Kasalath' and 'Nipponbare' in the preferential accumulation of CRR elements, and the expansion of CentO satellite repeats within the core domain of Cen8. Together, the results provide insights into the recent proliferation of LTR-retrotransposons, and the rapid expansion of CentO satellite repeats, underlying the dynamic variation and plasticity of plant centromeres.

Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay.

PubMed

Lakshmipriya, Thangavel; Gopinath, Subash C B; Tang, Thean-Hock

2016-01-01

Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.

Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay

PubMed Central

Lakshmipriya, Thangavel; Gopinath, Subash C. B.; Tang, Thean-Hock

2016-01-01

Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors. PMID:26954237

A tuberculosis vaccine based on phosphoantigens and fusion proteins induces distinct gammadelta and alphabeta T cell responses in primates.

PubMed

Cendron, Delphine; Ingoure, Sophie; Martino, Angelo; Casetti, Rita; Horand, Françoise; Romagné, François; Sicard, Hélène; Fournié, Jean-Jacques; Poccia, Fabrizio

2007-02-01

Phosphoantigens are mycobacterial non-peptide antigens that might enhance the immunogenicity of current subunit candidate vaccines for tuberculosis. However, their testing requires monkeys, the only animal models suitable for gammadelta T cell responses to mycobacteria. Thus here, the immunogenicity of 6-kDa early secretory antigenic target-mycolyl transferase complex antigen 85B (ESAT-6-Ag85B) (H-1 hybrid) fusion protein associated or not to a synthetic phosphoantigen was compared by a prime-boost regimen of two groups of eight cynomolgus. Although phosphoantigen activated immediately a strong release of systemic Th1 cytokines (IL-2, IL-6, IFN-gamma, TNF-alpha), it further anergized blood gammadelta T lymphocytes selectively. By contrast, the hybrid H-1 induced only memory alphabeta T cell responses, regardless of phosphoantigen. These latter essentially comprised cytotoxic T lymphocytes specific for Ag85B (on average + 430 cells/million PBMC) and few IFN-gamma-secreting cells (+ 40 cells/million PBMC, equally specific for ESAT-6 and for Ag85B). Hence, in macaques, a prime-boost with the H-1/phosphoantigen subunit combination induces two waves of immune responses, successively by gammadelta T and alphabeta T lymphocytes.

Granzyme B as a diagnostic marker of tuberculosis in patients with and without HIV coinfection.

PubMed

Sarkar, Pronoti; Mitra, Soumik; Pant, Priyannk; Kotwal, Aarti; Kakati, Barnali; Masih, Victor; Sindhwani, Girish; Biswas, Debasis

2016-05-01

Immunodiagnostic tests for tuberculosis (TB) are based on the estimation of interferon γ (IFN-γ) or IFN-γ-secreting CD4(+) T cells following ex vivo stimulation with ESAT6 and CFP-10. Sensitivity of these tests is likely to be compromised in CD4(+) T-cell-depleted situations, like HIV-TB coinfection. CD4(+) and CD8(+) T cells, isolated from 3 groups, viz., HIV-negative patients with active TB, HIV-TB coinfected patients, and healthy household contacts (HHCs) were cocultivated with autologous dendritic cells, and the cytokine response to rESAT6 stimulation was compared between groups in supernatants. While CD4(+) T-cell stimulation yielded significantly elevated levels of IFN-γ and interleukin 4 in HIV-negative TB patients, compared to HHCs, the levels of both these cytokines were nondiscriminatory between HIV-positive TB patients and HHCs. However, CD8(+) T-cell stimulation yielded significantly elevated granzyme B titers in both groups of patients, irrespective of HIV coinfection status. Hence, contrary to IFN-γ, granzyme B might be a useful diagnostic marker for Mycobacterium tuberculosis infection particularly in HIV coinfected patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Small Hydropower in Latvia and Intellectualization of its Operating Systems / Par Mazo HIDROENERĢĒTIKU LATVIJĀ un TĀS Staciju VADĪBAS SISTĒMAS INTELEKTUALIZĀCIJU

NASA Astrophysics Data System (ADS)

Mahnitko, A.; Gerhards, J.; Linkevics, O.; Varfolomejeva, R.; Umbrasko, I.

2013-12-01

The authors estimate the potential for power generation from water resources of small and medium-sized rivers, which are abundant in Latvia. They propose the algorithm for optimal operation of a small-scale hydropower plant (SHPP) at the chosen optimality criterion in view of the plant's participation in the market. The choice of SHPP optimization algorithm is made based on two mathematical programming methods - dynamic and generalized reduced gradient ones. Approbation of the algorithm is illustrated by an example of optimized SHPP operation. Darbā analizētas tradicionālo un pieejamo vietējo atjaunojamo energoresursu - mazo un vidējo upju hidroresursa izmantošanas iespējas Latvijas enerģētikā. Tiek sniegts faktiskais materiāls šajā jautājumā, kas iegūts, balstoties uz oficiālos avotos publicētiem citu autoru iepriekš veiktajiem pētījumiem. Tiek atzīmēts, ka teritoriju, kas atrodas mazo upju tuvumā un nav ietvertas centralizētās elektroapgādes sistēmā, saimnieciskā apgūšana rada apstākļus patērētāju stimulēšanai izmantot autonomus vietējos energoresursus, ieskaitot hidroenerģiju, izmantojošas mazas jaudas energoiekārtas. Atjaunojamās enerģijas tehnoloģiju un iekārtu pastāvīga attīstība un pilnveidošanās veicinās mazo upju plūsmas izmantošanas elektroenerģijas ražošanas efektivitātes paaugstināšanos. Mūsdienu enerģētikas attīstības koncepcija, kas balstīta uz viedo tīklu (smart grids) izveidi, ļauj paaugstināt mazās hidroenerģētikas darbības efektivitāti, integrējot to elektroenerģētiskajā sistēmā. Mazo hidroelektrostaciju (MHES) darbības vadības sistēmas intelektualizācijas pamatā jābūt kompleksam algoritmam un programmām, kas ļauj tiešsaistes (online) režīmā nodrošināt izdevīgu MHES darbības grafiku (režīmu) maksimālā ienākuma gūšanai, balstoties uz zināmu elektroenerģijas cenas prognozi attiecīgajam laika periodam (diennaktij). MHES darbības optimiz

MAGMA: A Liquid Software Approach to Fault Tolerance, Computer Network Security, and Survivable Networking

DTIC Science & Technology

2001-12-01

and Lieutenant Namik Kaplan , Turkish Navy. Maj Tiefert’s thesis, “Modeling Control Channel Dynamics of SAAM using NS Network Simulation”, helped lay...DEC99] Deconinck , Dr. ir. Geert, Fault Tolerant Systems, ESAT / Division ACCA , Katholieke Universiteit Leuven, October 1999. [FRE00] Freed...Systems”, Addison-Wesley, 1989. [KAP99] Kaplan , Namik, “Prototyping of an Active and Lightweight Router,” March 1999 [KAT99] Kati, Effraim

Affinity study on bovine serum albumin's peptides to amphiphilic gold nanoparticles: A test of epitopes and non-epitopes

NASA Astrophysics Data System (ADS)

Yuan, Ming; Li, Wanrong; Yang, Mingming; Huang, Xiufeng; Bai, Zhijun; Liu, Yushuang; Cai, Weijun; Wang, Yuqin; Zhang, Feng

2017-09-01

It is an inevitable event that nanoparticles (NPs) will encounter proteins/peptides in nano-medicine, so it has been significant to know their interaction mechanism before in vivo applications. Previously, a 105-amino-acid sequence had been reported as the binding site between bovine serum albumin (BSA) and amphiphilic polymer coated gold nanoparticles (AP-AuNPs) along with a mortise-tenon joint hypothesis. This article tested the affinity difference between two epitope peptide sequences such as: LGEYGFQNALIVR (S1), DAFLGSFLYEYSR (S2) and one non-epitope peptide sequence as: FDEHVKLVNELTEF (S3). With the photoluminescent amino acid residues, the fluorescence quenching method based on the nanometal surface energy transfer (NSET) principle was able to study the thermodynamics of the current binding system. The binding constants (Ka) were determined and followed the order as: Ka-S1 > Ka-S2 >> Ka-S3. Moreover, Hill constants indicated that cooperativity only presented in the interactions of AP-AuNP with either S1 or S2, but not for S3. Moreover, gel electrophoresis, surface plasmon resonance, atomic force microscopy and three dimensional fluorescence microscopy were all also used to comprehensively analyse the binding interaction mechanism. These results further provided useful information to better understand the mortise-tenon joint, which might find applications to nanofabrication and biomedicine.

Structural and chemical requirements for hydroxychlorobiphenyls to uncouple rat liver mitochondria and potentiation of uncoupling with aroclor 1254.

PubMed

Ebner, K V; Braselton, W E

1987-01-01

Rat hepatic mitochondrial permeability and succinate + valinomycin-dependent swelling were studied in the presence of hydroxy derivatives of polychlorinated biphenyls (PCBOHs), Aroclor 1254 (ARO) and combinations of both. PCBOHs with two or more chlorines and pKas greater than 8.0 (PCBOH I) induced passive swelling in a potassium acetate-sucrose medium (pH 7.2), maximally stimulated succinate respiration, and suppressed ADP-stimulated H+ uptake. Mono- and certain dichlorinated biphenylols with similar high pKas (PCBOH II) were ineffective. Para-hydroxy PCBs with chlorines substituted in the 3,5 positions and with pKas near 6.8 (PCBOH III) inhibited succinate + valinomycin swelling and ADP-stimulated H+ and oxygen uptake. The efficacy of both PCBOH I and III derivatives required the presence of a hydroxyl moiety and increased directly with the degree of chlorination. Coplanarity was not a determining factor for PCBOH I compounds. ARO activated succinate + valinomycin swelling at low concentrations (3-25 nmol/mg protein) but inhibited at higher concentrations (greater than 40 nmol/mg). Activating concentrations of ARO potentiated the influence of PCBOHs on mitochondria. The uncoupling effects of the PCBOHs and ARO involved permeability changes of the inner membrane, respiratory inhibition, or combinations of both.

Korean American women's perceptions about physical examinations and cancer screening services offered in Korea: the influences of medical tourism on Korean Americans.

PubMed

Oh, Kyeung Mi; Jun, Jungmi; Zhou, Qiuping; Kreps, Gary

2014-04-01

Cancer is the leading cause of death for Korean-Americans (KAs), while cancer screening rates among KAs have been consistently low. Seven semi-structured focus group interviews with 34 KA women aged 40 or older in the Washington, DC metropolitan area were conducted to explore the perceptions of KA women about seeking physical examinations and cancer screening services in Korea. Data were analyzed using a framework approach. Informants positively perceived the use of health screening services in Korea in comparison to seeking such services in the US. Decision-making factors included cost benefits, high quality services, and more convenient screening procedures in Korea. These benefits outweighed the risks of delaying health care and travelling a vast distance with incurring additional travel costs. Motivations to seek these services in Korea included opportunities to visit their homeland and to enjoy comfortable communication with their native language. The increase of available information about Korean medical services due to the industry's aggressive marketing/PR was identified as a facilitator. Most informants did not recognize possible negative health outcomes of obtaining services in Korea such as inappropriate follow up care if having abnormal findings. Educational programs are needed to educate KAs about the benefits and risks of getting the services in Korea and proper follow up care in the US. Health care providers need to know the different cancer risks and screening needs for this population.

Development of a Gene Expression Assay for the Diagnosis of Mycobacterium bovis Infection in African Lions (Panthera leo).

PubMed

Olivier, T T; Viljoen, I M; Hofmeyr, J; Hausler, G A; Goosen, W J; Tordiffe, A S W; Buss, P; Loxton, A G; Warren, R M; Miller, M A; van Helden, P D; Parsons, S D C

2017-06-01

Mycobacterium bovis infection, the cause of bovine tuberculosis (BTB), is endemic in wildlife in the Kruger National Park (KNP), South Africa. In lions, a high infection prevalence and BTB mortalities have been documented in the KNP; however, the ecological consequences of this disease are currently unknown. Sensitive assays for the detection of this infection in this species are therefore required. Blood from M. bovis-exposed, M. bovis-unexposed, M. tuberculosis-exposed and M. bovis-infected lions was incubated in QuantiFERON ® -TB Gold (QFT) tubes containing either saline or ESAT-6/CFP-10 peptides. Using qPCR, selected reference genes were evaluated for expression stability in these samples and selected target genes were evaluated as markers of antigen-dependent immune activation. The abundance of monokine induced by gamma interferon (MIG/CXCL9) mRNA, measured in relation to that of YWHAZ, was used as a marker of ESAT-6/CFP-10 sensitization. The gene expression assay results were compared between lion groups, and lenient and stringent diagnostic cut-off values were calculated. This CXCL9 gene expression assay combines a highly specific stimulation platform with a sensitive diagnostic marker that allows for discrimination between M. bovis-infected and M. bovis-uninfected lions. © 2015 Blackwell Verlag GmbH.

Carbonic anhydrase activators. Activation of isoforms I, II, IV, VA, VII, and XIV with L- and D-phenylalanine and crystallographic analysis of their adducts with isozyme II: stereospecific recognition within the active site of an enzyme and its consequences for the drug design.

PubMed

Temperini, Claudia; Scozzafava, Andrea; Vullo, Daniela; Supuran, Claudiu T

2006-05-18

Activation of six human brain carbonic anhydrases (hCAs, EC 4.2.1.1), hCA I, II, IV, VA, VII, and XIV, with l-/d-phenylalanine was investigated kinetically and by X-ray crystallography. l-Phe was a potent activator of isozymes I, II, and XIV (K(A)s of 13-240 nM), a weaker activator of hCA VA and VII (K(A)s of 9.8-10.9 microM), and a quite inefficient hCA IV activator (K(A) of 52 microM). d-Phe showed good hCA II activatory properties (K(A) of 35 nM), being a moderate hCA VA, VII, and XIV (K(A)s of 4.6-9.7 microM) and a weak hCA I and IV activator (K(A)s of 63-86 microM). X-ray crystallography of the hCA II-l-Phe/d-Phe adducts showed the activators to be anchored at the entrance of the active site, participating in numerous bonds and hydrophobic interactions with amino acid residues His64, Thr200, Trp5, and Pro201. This is the first study showing different binding modes of stereoisomeric activators within the hCA II active site, with consequences for overall proton transfer processes (rate-determining for the catalytic cycle). It also points out differences of activation efficiency between various isozymes with structurally related activators, exploitable for designing alternative proton transfer pathways. CA activators may lead to the design of pharmacologically useful derivatives for the enhancement of synaptic efficacy, which may represent a conceptually new approach for the treatment of Alzheimer's disease, aging, and other conditions in which spatial learning and memory therapy must be enhanced. As the blood and brain concentrations of l-Phe are quite variable (30-73 microM), activity of some brain CAs may strongly be influenced by the level of activator(s) present in such tissues.

Live Attenuated Salmonella Vaccines Displaying Regulated Delayed Lysis and Delayed Antigen Synthesis To Confer Protection against Mycobacterium tuberculosis

PubMed Central

Juárez-Rodríguez, María Dolores; Yang, Jiseon; Kader, Rebin; Alamuri, Praveen; Curtiss, Roy

2012-01-01

Live recombinant attenuated Salmonella vaccine (RASV) strains have great potential to induce protective immunity against Mycobacterium tuberculosis by delivering M. tuberculosis antigens. Recently, we reported that, in orally immunized mice, RASV strains delivering the M. tuberculosis early secreted antigenic target 6-kDa (ESAT-6) protein and culture filtrate protein 10 (CFP-10) antigens via the Salmonella type III secretion system (SopE amino-terminal region residues 1 to 80 with two copies of ESAT-6 and one copy of CFP-10 [SopENt80-E2C]) afforded protection against aerosol challenge with M. tuberculosis. Here, we constructed and evaluated an improved Salmonella vaccine against M. tuberculosis. We constructed translational fusions for the synthesis of two copies of ESAT-6 plus CFP-10 fused to the OmpC signal sequence (OmpCSS-E2C) and amino acids 44 to 338 of antigen 85A (Ag85A294) flanked by the signal sequence (SS) and C-terminal peptide (CT) of β-lactamase (BlaSS-Ag85A294-BlaCT) to enable delivery via the Salmonella type II secretion system. The genes expressing these proteins were cloned as an operon transcribed from Ptrc into isogenic Asd+/MurA+ pYA3681 lysis vector derivatives with different replication origins (pBR, p15A, pSC101), resulting in pYA4890, pYA4891, and pYA4892 for SopENt80-E2C/Ag85A294 synthesis and pYA4893 and pYA4894 for OmpCSS-E2C/Ag85A294 synthesis. Mice orally immunized with the RASV χ11021 strain engineered to display regulated delayed lysis and regulated delayed antigen synthesis in vivo and harboring pYA4891, pYA4893, or pYA4894 elicited significantly greater humoral and cellular immune responses, and the RASV χ11021 strain afforded a greater degree of protection against M. tuberculosis aerosol challenge in mice than RASVs harboring any other Asd+/MurA+ lysis plasmid and immunization with M. bovis BCG, demonstrating that RASV strains displaying regulated delayed lysis with delayed antigen synthesis resulted in highly immunogenic

Decarboxylation of malonyl-(acyl carrier protein) by 3-oxoacyl-(acyl carrier protein) synthases in plant fatty acid biosynthesis.

PubMed Central

Winter, E; Brummel, M; Schuch, R; Spener, F

1997-01-01

In order to identify regulatory steps in fatty acid biosynthesis, the influence of intermediate 3-oxoacyl-(acyl carrier proteins) (3-oxoacyl-ACPs) and end-product acyl-ACPs of the fatty acid synthase reaction on the condensation reaction was investigated in vitro, using total fatty acid synthase preparations and purified 3-oxoacyl-ACP synthases (KASs; EC 2.3.1.41) from Cuphea lanceolata seeds. KAS I and II in the fatty acid synthase preparations were assayed for the elongation of octanoyl- and hexadecanoyl-ACP respectively, and the accumulation of the corresponding condensation product 3-oxoacyl-ACP was studied by modulating the content of the reducing equivalentS NADH and NADPH. Complete omission of reducing equivalents resulted with either KAS in the abnormal synthesis of acetyl-ACP from malonyl-ACP by a decarboxylation reaction. Supplementation with NADPH or NADH, separately or in combination with recombinant 3-oxoacyl-ACP reductase (EC 1.1.1.100), led to a decrease in the amount of acetyl-ACP and a simultaneous increase in elongation products. This demonstrates that the accumulation of 3-oxoacyl-ACP inhibits the condensation reaction on the one hand, and induces the decarboxylation of malonyl-ACP on the other. By carrying out similar experiments with purified enzymes, this decarboxylation was attributed to the action of KAS. Our data point to a regulatory mechanism for the degradation of malonyl-ACP in plants which is activated by the accumulation of the fatty acid synthase intermediate 3-oxoacyl-ACP. PMID:9020860

Decarboxylation of malonyl-(acyl carrier protein) by 3-oxoacyl-(acyl carrier protein) synthases in plant fatty acid biosynthesis.

PubMed

Winter, E; Brummel, M; Schuch, R; Spener, F

1997-01-15

In order to identify regulatory steps in fatty acid biosynthesis, the influence of intermediate 3-oxoacyl-(acyl carrier proteins) (3-oxoacyl-ACPs) and end-product acyl-ACPs of the fatty acid synthase reaction on the condensation reaction was investigated in vitro, using total fatty acid synthase preparations and purified 3-oxoacyl-ACP synthases (KASs; EC 2.3.1.41) from Cuphea lanceolata seeds. KAS I and II in the fatty acid synthase preparations were assayed for the elongation of octanoyl- and hexadecanoyl-ACP respectively, and the accumulation of the corresponding condensation product 3-oxoacyl-ACP was studied by modulating the content of the reducing equivalentS NADH and NADPH. Complete omission of reducing equivalents resulted with either KAS in the abnormal synthesis of acetyl-ACP from malonyl-ACP by a decarboxylation reaction. Supplementation with NADPH or NADH, separately or in combination with recombinant 3-oxoacyl-ACP reductase (EC 1.1.1.100), led to a decrease in the amount of acetyl-ACP and a simultaneous increase in elongation products. This demonstrates that the accumulation of 3-oxoacyl-ACP inhibits the condensation reaction on the one hand, and induces the decarboxylation of malonyl-ACP on the other. By carrying out similar experiments with purified enzymes, this decarboxylation was attributed to the action of KAS. Our data point to a regulatory mechanism for the degradation of malonyl-ACP in plants which is activated by the accumulation of the fatty acid synthase intermediate 3-oxoacyl-ACP.

Expansion of Pathogen-Specific Mono- and Multifunctional Th1 and Th17 Cells in Multi-Focal Tuberculous Lymphadenitis

PubMed Central

Kumar, Nathella Pavan; Sridhar, Rathinam; Banurekha, Vaithilingam V.; Nair, Dina; Jawahar, Mohideen S.; Nutman, Thomas B.; Babu, Subash

2013-01-01

Background Th1 and Th17 responses are known to play an important role in immunity to pulmonary tuberculosis (PTB), although little is known about their role in extrapulmonary forms of tuberculosis (TB). Methods To identify the role of Th1, Th17, and Th22 cells in multi-focal TB lymphadenitis (TBL), we examined mycobacteria–specific immune responses in the whole blood of individuals with PTB (n = 20) and compared them with those with TBL (n = 25). Results Elevated frequencies of CD4+ T cells expressing IFN- γ, TNF-α, and IL-2 were present in individuals with TBL compared with those with PTB at baseline and in response to ESAT-6 and CFP-10. Similarly, increased frequencies of CD4+ T cells expressing IL-17A, IL-17F, and IFN-γ were also present in individuals with TBL at baseline and following ESAT-6 and CFP-10 stimulation although no significant difference in frequency of Th22 cells was observed. Finally, frequencies of Th1 (but not Th17) cells exhibited a significantly negative correlation with natural regulatory T cell frequencies at baseline. Conclusions Multi-focal TB lymphadenitis is therefore characterized by elevated frequencies of Th1 and Th17 cells, indicating that Th1 and Th17 responses in TB disease are probably correlates of disease severity rather than of protective immunity. PMID:23451159

The ASCENT (Allocation System Changes for Equity in Kidney Transplantation) Study: a Randomized Effectiveness-Implementation Study to Improve Kidney Transplant Waitlisting and Reduce Racial Disparity.

PubMed

Patzer, Rachel E; Smith, Kayla; Basu, Mohua; Gander, Jennifer; Mohan, Sumit; Escoffery, Cam; Plantinga, Laura; Melanson, Taylor; Kalloo, Sean; Green, Gary; Berlin, Alex; Renville, Gary; Browne, Teri; Turgeon, Nicole; Caponi, Susan; Zhang, Rebecca; Pastan, Stephen

2017-05-01

The United Network for Organ Sharing (UNOS) implemented a new Kidney Allocation System (KAS) in December 2014 that is expected to substantially reduce racial disparities in kidney transplantation among waitlisted patients. However, not all dialysis facility clinical providers and end stage renal disease (ESRD) patients are aware of how the policy change could improve access to transplant. We describe the ASCENT (Allocation System Changes for Equity in KidNey Transplantation) study, a randomized controlled effectiveness-implementation study designed to test the effectiveness of a multicomponent intervention to improve access to the early steps of kidney transplantation among dialysis facilities across the United States. The multicomponent intervention consists of an educational webinar for dialysis medical directors, an educational video for patients and an educational video for dialysis staff, and a dialysis-facility specific transplant performance feedback report. Materials will be developed by a multidisciplinary dissemination advisory board and will undergo formative testing in dialysis facilities across the United States. This study is estimated to enroll ~600 U.S. dialysis facilities with low waitlisting in all 18 ESRD Networks. The co-primary outcomes include change in waitlisting, and waitlist disparity at 1 year; secondary outcomes include changes in facility medical director knowledge about KAS, staff training regarding KAS, patient education regarding transplant, and a medical director's intent to refer patients for transplant evaluation. The results from the ASCENT study will demonstrate the feasibility and effectiveness of a multicomponent intervention designed to increase access to the deceased-donor kidney waitlist and reduce racial disparities in waitlisting.

HBV-related health behaviors in a socio-cultural context: perspectives from Khmers and Koreans.

PubMed

Lee, Haeok; Kiang, Peter; Chea, Phala; Peou, Sonith; Tang, Shirley S; Yang, Jinhwang; Fawcett, Jacqueline; Hann, Hie-Won

2014-05-01

The aim of this study is to explore factors influencing health and health care within the sociocultural context of Cambodian Americans (CAs or Khmers) and Korean Americans (KA) and to examine intergroup similarities and differences between CAs and KAs, focusing on hepatitis B virus (HBV) and liver cancer prevention behaviors. The study used a qualitative design guided by the revised Network Episode Model (NEM) and informed by ethnographic analysis. Focus group interviews with key informants among CA community health leaders (CHLs, n=14) and individual interviews with key informants of KA CHLs (n=9) were audiotaped and transcribed. Three categories that influenced HBV and liver cancer prevention emerged from both CAs and KAs: the socio-cultural, individual, and behavioral. Four additional subcategories (sub-themes) of sociocultural were identified as socio-history, socio-medicine, socio-linguistic, and socio-health resources. Both CAs and KAs, however, have low levels of knowledge and significant misunderstandings about HBV infection. The study identifies and compares the social-cultural determinant for HBV and liver cancer and highlights the factors of education, intercultural communication, and interactions within socio-cultural contexts of CA and KA subgroups. In general, conceptual overlaps are apparent between Khmers (from now on, the terms, CA and Khmer, will be used interchangeably) and Koreans except for the sub-theme of socio-history. However, differences in concept-specific attributes point to the need to account for differing conceptualizations and implications of specific ethnic groups' sociocultural contexts, and to design contextually-relevant outreach and educational interventions for targeted AAPI subgroups. Copyright © 2014 Elsevier Inc. All rights reserved.

HBV-Related Health Behaviors in a Socio-Cultural Context: Perspectives from Khmers and Koreans

PubMed Central

Lee, Haeok; Kiang, Peter; Chea, Phala; Peou, Sonith; Tang, Shirley S.; Yang, JinHwang; Fawcett, Jacqueline; Hann, Hie-Won

2014-01-01

Purpose To explore factors influencing health and health care within the sociocultural context of Cambodian Americans (CAs or Khmers) and Korean Americans (KA) and to examine intergroup similarities and differences between CAs and KAs, focusing on hepatitis B virus (HBV) and liver cancer prevention behaviors. Methods The study used a qualitative design guided by the revised Network Episode Model (NEM) and informed by ethnographic analysis. Focus group interviews with key informants among CA community health leaders (CHLs, n=14) and individual interviews with key informants of KA CHLs (n=9) were audiotaped and transcribed. Results Three categories that influenced HBV and liver cancer prevention emerged from both CAs and KAs: the socio-cultural, individual, and behavioral. Four additional sub-categories (sub-themes) of sociocultural were identified as socio-history, socio-medicine, socio-linguistic, and socio-health resources. Both CAs and KAs, however, have low levels of knowledge and significant misunderstandings about HBV infection. Conclusions The study identifies and compares the social-cultural determinant for HBV and liver cancer and highlights the factors of education, intercultural communication, and interactions within socio-cultural contexts of CA and KA subgroups. In general, conceptual overlaps are apparent between Khmers (from now on, the terms, CA and Khmer, will be used interchangeably) and Koreans except for the sub-theme of socio-history. However, differences in concept-specific attributes point to the need to account for differing conceptualizations and implications of specific ethnic groups’ sociocultural contexts, and to design contextually-relevant outreach and educational interventions for targeted AAPI subgroups. PMID:24355416

Unmet Needs for Social Support and Effects on Diabetes Self-care Activities in Korean Americans With Type 2 Diabetes

PubMed Central

Song, Youngshin; Song, Hee-Jung; Han, Hae-Ra; Park, So-Youn; Nam, Soohyun; Kim, Miyong T.

2013-01-01

Objective The purpose of this study was (1) to characterize the primary sources of social support and the extent of unmet needs for support (defined as the gap between social support needs and the receipt of social support) in a sample of Korean Americans (KAs) with type 2 diabetes and (2) to examine the effect of unmet needs for support on their self-care activities. Methods Baseline data obtained from a community-based intervention trial were used for this study of 83 middle-aged KAs with type 2 diabetes. Study design and data analysis were guided by social cognitive theory. The key variables were dictated the order of the variables in multivariate regression analysis. Results Our findings indicated that for diabetic KAs, the primary source of social support differed according to gender. Unmet needs for support were significantly associated with self-care activities, but the amount of support needs and of social support received were not. Multivariate analysis also confirmed that unmet needs for social support are a significant strong predictor of inadequate type 2 diabetes self-care activities, after controlling for other covariates. The hierarchical regression model explained about 30% of total variance in self-care activities. Conclusions The findings highlight the importance of considering unmet needs for social support when addressing self-care activities in type 2 diabetes patients. Future interventions should focus on filling gaps in social support and tailoring approaches according to key determinants, such as gender or education level, to improve self-care activities in the context of type 2 diabetes care. PMID:22222514

Use of natural variation reveals core genes in the transcriptome of iron-deficient Arabidopsis thaliana roots

PubMed Central

Stein, Ricardo J.; Waters, Brian M.

2012-01-01

Iron (Fe) is an essential mineral micronutrient for plants and animals. Plants respond to Fe deficiency by increasing root uptake capacity. Identification of gene networks for Fe uptake and homeostasis could result in improved crop growth and nutritional value. Previous studies have used microarrays to identify a large number of genes regulated by Fe deficiency in roots of three Arabidopsis ecotypes. However, a large proportion of these genes may be involved in secondary or genotype-influenced responses rather than in a universal role in Fe uptake or homeostasis. Here we show that a small percentage of the Fe deficiency transcriptome of two contrasting ecotypes, Kas-1 and Tsu-1, was shared with other ecotypes. Kas-1 and Tsu-1 had different timing and magnitude of ferric reductase activity upon Fe withdrawal, and different categories of overrepresented Fe-regulated genes. To gain insights into universal responses of Arabidopsis to Fe deficiency, the Kas-1 and Tsu-1 transcriptomes were compared with those of Col-0, Ler, and C24. In early Fe deficiency (24–48 h), no Fe-downregulated genes and only 10 upregulated genes were found in all ecotypes, and only 20 Fe-downregulated and 58 upregulated genes were found in at least three of the five ecotypes. Supernode gene networks were constructed to visualize conserved Fe homeostasis responses. Contrasting gene expression highlighted different responses to Fe deficiency between ecotypes. This study demonstrates the use of natural variation to identify central Fe-deficiency-regulated genes in plants, and identified genes with potential new roles in signalling during Fe deficiency. PMID:22039296

Workshop on Scientific Analysis and Policy in Network Security

DTIC Science & Technology

2010-09-10

IBBT Dcpt. Electrical Engineering-ESAT/COSlC. Kasteelpark Arenberg 10 Bus 2446, B-3001 Leuven. Belgium bart.preneelflesat.kuleuven.be Abstract. This...Bouissou1,3 1 Electricity de France R&D, 1 avenue du General de Gaulle, 92141 Clamart, France 2 Institut Telecom, Telecom ParisTech, 46 rue Barrault...for any x G Aj1; /, !,_0(x) is a probability distribution on AQ, such that if x G S{i then £jeS, (/’.^(.OXj) = L illul if x e Dii > then £j

Risk factors for increased immune reconstitution in response to Mycobacterium tuberculosis antigens in tuberculosis HIV-infected, antiretroviral-naïve patients.

PubMed

da Silva, Tatiana Pereira; Giacoia-Gripp, Carmem Beatriz Wagner; Schmaltz, Carolina A; Sant'Anna, Flavia Marinho; Saad, Maria Helena; Matos, Juliana Arruda de; de Lima E Silva, Julio Castro Alves; Rolla, Valeria Cavalcanti; Morgado, Mariza Gonçalves

2017-09-06

Little is known regarding the restoration of the specific immune response after combined antiretroviral therapy (cART) and anti-tuberculosis (TB) therapy introduction among TB-HIV patients. In this study, we examined the immune response of TB-HIV patients to Mycobacterium tuberculosis (Mtb) antigens to evaluate the response dynamics to different antigens over time. Moreover, we also evaluated the influence of two different doses of efavirenz and the factors associated with immune reconstitution. This is a longitudinal study nested in a clinical trial, where cART was initiated during the baseline visit (D0), which occurred 30 ± 10 days after the introduction of anti-TB therapy. Follow-up visits were performed at 30, 60, 90 and 180 days after cART initiation. The production of IFN-γ upon in vitro stimulation with Mtb antigens purified protein derivative (PPD), ESAT-6 and 38 kDa/CFP-10 using ELISpot was examined at baseline and follow-up visits. Sixty-one patients, all ART-naïve, were selected and included in the immune reconstitution analysis; seven (11.5%) developed Immune Reconstitution Inflammatory Syndrome (IRIS). The Mtb specific immune response was higher for the PPD antigen followed by 38 kDa/CFP-10 and increased in the first 60 days after cART initiation. In multivariate analysis, the variables independently associated with increased IFN-γ production in response to PPD antigen were CD4 + T cell counts <200 cells/mm 3 at baseline, age, site of tuberculosis, 800 mg efavirenz dose and follow-up CD4 + T cell counts. Moreover, the factors associated with the production of IFN-γ in response to 38 kDa/CFP-10 were detectable HIV viral load (VL) and CD4 + T cell counts at follow-up visits of ≥200 cells/mm 3 . These findings highlight the differences in immune response according to the specificity of the Mtb antigen, which contributes to a better understanding of TB-HIV immunopathogenesis. IFN-γ production elicited by PPD and 38 kDa/CFP-10 antigens

Evaluation of a New IFN-γ Release Assay for Rapid Diagnosis of Active Tuberculosis in a High-Incidence Setting.

PubMed

Li, Gen; Li, Feng; Zhao, Hui-Min; Wen, Han-Li; Li, Hai-Cong; Li, Chun-Ling; Ji, Ping; Xu, Peng; Wu, Kang; Hu, Zhi-Dong; Lu, Shui-Hua; Lowrie, Douglas B; Lv, Jian-Xin; Fan, Xiao-Yong

2017-01-01

Blood-based interferon-gamma (IFN-γ) release assays (IGRAs) have been proven to be useful in the diagnosis of Mycobacterium tuberculosis ( Mtb ) infection. However, IGRAs have not been recommended for clinical practice in most low-income settings due to cost-intensive limitations and shortage of clinical data available. The established T-SPOT. TB assay containing Mtb -specific antigens ESAT-6 and CFP10 are widely used for immunodiagonsis of Mtb infection, but the high cost is one of the restricting factors against its clinical application in the developing countries. More recently, a cost-saving IGRA assay, TS-SPOT, was approved in China. This new assay contains an additional antigen Rv3615c. Rv3615c contains broadly recognized CD4 + and CD8 + epitopes, and T-cell responses to Rv3615c are as specific for Mtb infection as the responses to ESAT-6 and CFP10 in both Mtb -infected humans and M. bovis -infected cattle. Therefore, we assessed the likely effect of inclusion of Rv3615c as stimulus besides ESAT-6 and CFP10 in an IGRA assay and evaluated the performance of TS-SPOT for diagnosis of Mtb infection and active TB compared with T-SPOT. TB . We tested 155 active TB patients, 90 non-TB lung disease patients, and 55 healthy individuals. The results presented an improved positive rate for diagnosis of active TB and Mtb infection, that could be attributable to inclusion of Rv3615c in the mixture of stimulatory antigens. The diagnostic efficiency of TS-SPOT assay for active TB was as follows: sensitivity 80.00%, specificity 83.45%, positive predictive value (PPV) 83.78%, negative predictive value (NPV) 83.45%, positive likelihood ratio (LR+) 4.83, and negative likelihood ratio (LR-) 0.24. The results were similar to those of T-SPOT. TB , with an excellent agreement (κ = 0.91, 95% CI: 0.85-0.95) being observed between these two assays. The sensitivities of the TS-SPOT assay varied for patients with different forms of active TB, with the highest sensitivity for patients

Cytokine response to selected MTB antigens in Ghanaian TB patients, before and at 2 weeks of anti-TB therapy is characterized by high expression of IFN-γ and Granzyme B and inter- individual variation.

PubMed

Mensah, Gloria Ivy; Addo, Kennedy Kwasi; Tetteh, John Amissah; Sowah, Sandra; Loescher, Thomas; Geldmacher, Christof; Jackson-Sillah, Dolly

2014-09-10

There has been a long held belief that patients with drug-susceptible TB are non-infectious after two weeks of therapy. Recent microbiological and epidemiological evidence has challenged this dogma, however, the nature of the Mtb-specific cellular immune response during this period has not been adequately investigated. This knowledge could be exploited in the development of immunological biomarkers of early treatment response. Cellular response to four Mtb infection phase-dependent antigens, ESAT-6/CFP-10 fusion protein and three DosR encoded proteins (Rv1733c, Rv2029c, Rv2628) were evaluated in a Ghanaian TB cohort (n=20) before and after 2 weeks of anti TB therapy. After 6-days in vitro stimulation, Peripheral blood mononuclear cell (PBMC) culture supernatant was harvested and the concentration of IFN-γ, Granzyme B, IL-10, IL-17, sIL2Rα and TNF-α were determined in a 6-plex Luminex assay. Frequencies of IFN-γ + CD4 and CD8 T cells were also determined in an intracellular cytokine assay. All antigens induced higher levels of IFN-γ, followed by Granzyme B, TNF-α and IL-17 and low levels of IL-10 and sIL-2R-α in PBMC before treatment and after 2 weeks of treatment. Median cytokine levels of IFN-γ, Granzyme B, IL-17 and sIL-2R-α increased during week two, but it was significant for only Rv1733-specific production of Granzyme B (P = 0. 013). The median frequency of antigen specific IFN-γ + CD4 T cells increased at week two; however, only the increase in the ESAT-6/CFP-10-specific response was significant (P = 0. 0008). In contrast, the median frequency of ESAT-6/CFP-10- specific IFN-γ + CD8 T cell responses declined during week two (P = 0. 0024). Additionally, wide inter-individual variation with three distinct patterns were observed; increase in all cytokine levels, decrease in all cytokine levels and fluctuating cytokine levels after 2 weeks of treatment. The second week of effective chemotherapy was characterized by a general increase in cytokine

Kinetic analyses and pyrolytic behavior of Para grass (Urochloa mutica) for its bioenergy potential.

PubMed

Ahmad, Muhammad Sajjad; Mehmood, Muhammad Aamer; Al Ayed, Omar S; Ye, Guangbin; Luo, Huibo; Ibrahim, Muhammad; Rashid, Umer; Arbi Nehdi, Imededdine; Qadir, Ghulam

2017-01-01

The biomass of Urochloa mutica was subjected to thermal degradation analyses to understand its pyrolytic behavior for bioenergy production. Thermal degradation experiments were performed at three different heating rates, 10, 30 and 50°Cmin -1 using simultaneous thermogravimetric-differential scanning calorimetric analyzer, under an inert environment. The kinetic analyses were performed using isoconversional models of Kissenger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The high heating value was calculated as 15.04MJmol -1 . The activation energy (E) values were shown to be ranging from 103 through 233 kJmol -1 . Pre-exponential factors (A) indicated the reaction to follow first order kinetics. Gibbs free energy (ΔG) was measured to be ranging from 169 to 173kJmol -1 and 168 to 172kJmol -1 , calculated by KAS and FWO methods, respectively. We have shown that Para grass biomass has considerable bioenergy potential comparable to established bioenergy crops such as switchgrass and miscanthus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbonic anhydrase activators: Activation of the β-carbonic anhydrase from Malassezia globosa with amines and amino acids.

PubMed

Vullo, Daniela; Del Prete, Sonia; Capasso, Clemente; Supuran, Claudiu T

2016-03-01

The β-carbonic anhydrase (CA, EC 4.2.1.1) from the dandruff producing fungus Malassezia globosa, MgCA, was investigated for its activation with amines and amino acids. MgCA was weakly activated by amino acids such as L-/D-His, L-Phe, D-DOPA, D-Trp, L-/D-Tyr and by the amine serotonin (KAs of 12.5-29.3μM) but more effectively activated by d-Phe, l-DOPA, l-Trp, histamine, dopamine, pyridyl-alkylamines, and 4-(2-aminoethyl)-morpholine, with KAs of 5.82-10.9μM. The best activators were l-adrenaline and 1-(2-aminoethyl)piperazine, with activation constants of 0.72-0.81μM. This study may help a better understanding of the activation mechanisms of β-CAs from pathogenic fungi as well as the design of tighter binding ligands for this enzyme which is a drug target for novel types of anti-dandruff agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of co-combustion characteristics of sewage sludge and coffee grounds mixtures using thermogravimetric analysis coupled to artificial neural networks modeling.

PubMed

Chen, Jiacong; Liu, Jingyong; He, Yao; Huang, Limao; Sun, Shuiyu; Sun, Jian; Chang, KenLin; Kuo, Jiahong; Huang, Shaosong; Ning, Xunan

2017-02-01

Artificial neural network (ANN) modeling was applied to thermal data obtained by non-isothermal thermogravimetric analysis (TGA) from room temperature to 1000°C at three different heating rates in air to predict the TG curves of sewage sludge (SS) and coffee grounds (CG) mixtures. A good agreement between experimental and predicted data verified the accuracy of the ANN approach. The results of co-combustion showed that there were interactions between SS and CG, and the impacts were mostly positive. With the addition of CG, the mass loss rate and the reactivity of SS were increased while charring was reduced. Measured activation energies (E a ) determined by the Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) methods deviated by <5%. The average value of E a (166.8kJ/mol by KAS and 168.8kJ/mol by OFW, respectively) was the lowest when the fraction of CG in the mixture was 40%. Copyright © 2016 Elsevier Ltd. All rights reserved.

High frequencies of circulating IFN-gamma-secreting CD8 cytotoxic T cells specific for a novel MHC class I-restricted Mycobacterium tuberculosis epitope in M. tuberculosis-infected subjects without disease.

PubMed

Pathan, A A; Wilkinson, K A; Wilkinson, R J; Latif, M; McShane, H; Pasvol, G; Hill, A V; Lalvani, A

2000-09-01

MHC class I-restricted CD8 cytotoxic T lymphocytes (CTL) are essential for protective immunity to Mycobacterium tuberculosis in animal models but their role in humans remains unclear. We therefore studied subjects who had successfully contained M. tuberculosis infection in vivo, i.e. exposed healthy household contacts and individuals with inactive self-healed pulmonary tuberculosis. Using the ELISPOT assay for IFN-gamma, we screened peptides from ESAT-6, a secreted antigen that is highly specific for M. tuberculosis. We identified a novel nonamer epitope: unstimulated peripheral blood-derived CD8 T cells displayed peptide-specific IFN-gamma release ex vivo while CD8 T cell lines and clones exhibited HLA-A68.02-restricted cytolytic activity and recognized endogenously processed antigen. The frequency of CD8 CTL specific for this single M. tuberculosis epitope, 1/2500 peripheral blood lymphocytes, was equivalent to the combined frequency of all IFN-gamma-secreting purified protein derivative-reactive T cells ex vivo. This highly focused CTL response was maintained in an asymptomatic contact over 2 years and is the most potent antigen-specific antimycobacterial CD8 CTL response hitherto described. Thus, human M. tuberculosis-specific CD8 CTL are not necessarily associated with active disease per se. Rather, our results are consistent with a protective role for these ESAT-6-specific CD8 T cells in the long-term control of M. tuberculosis in vivo in humans.

ReLiance: a machine learning and literature-based prioritization of receptor—ligand pairings

PubMed Central

Iacucci, Ernesto; Tranchevent, Léon-Charles; Popovic, Dusan; Pavlopoulos, Georgios A.; De Moor, Bart; Schneider, Reinhard; Moreau, Yves

2012-01-01

Motivation: The prediction of receptor—ligand pairings is an important area of research as intercellular communications are mediated by the successful interaction of these key proteins. As the exhaustive assaying of receptor—ligand pairs is impractical, a computational approach to predict pairings is necessary. We propose a workflow to carry out this interaction prediction task, using a text mining approach in conjunction with a state of the art prediction method, as well as a widely accessible and comprehensive dataset. Among several modern classifiers, random forests have been found to be the best at this prediction task. The training of this classifier was carried out using an experimentally validated dataset of Database of Ligand-Receptor Partners (DLRP) receptor—ligand pairs. New examples, co-cited with the training receptors and ligands, are then classified using the trained classifier. After applying our method, we find that we are able to successfully predict receptor—ligand pairs within the GPCR family with a balanced accuracy of 0.96. Upon further inspection, we find several supported interactions that were not present in the Database of Interacting Proteins (DIPdatabase). We have measured the balanced accuracy of our method resulting in high quality predictions stored in the available database ReLiance. Availability: http://homes.esat.kuleuven.be/~bioiuser/ReLianceDB/index.php Contact: yves.moreau@esat.kuleuven.be; ernesto.iacucci@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22962483

Psychometrics of Shared Decision Making and Communication as Patient Centered Measures for Two Language Groups

PubMed Central

Alvarez, Kiara; Wang, Ye; Alegria, Margarita; Ault-Brutus, Andrea; Ramanayake, Natasha; Yeh, Yi-Hui; Jeffries, Julia R.; Shrout, Patrick E.

2017-01-01

Shared decision-making (SDM) and effective patient-provider communication are key and interrelated elements of patient-centered care that impact health and behavioral health outcomes. Measurement of SDM and communication from the patient’s perspective is necessary in order to ensure that health care systems and individual providers are responsive to patient views. However, there is a void of research addressing the psychometric properties of these measures with diverse patients, including non-English speakers, and in the context of behavioral health encounters. This study evaluated the psychometric properties of two patient-centered outcome measures, the Shared Decision Making Questionnaire-9 (SDM-Q) and the Kim Alliance Scale-Communication Subscale (KAS-CM), in a sample of 239 English and Spanish-speaking behavioral health patients. One dominant factor was found for each scale and this structure was used to examine whether there was measurement invariance across the two language groups. One SDM-Q item was inconsistent with the configural invariance comparison and was removed. The remaining SDM-Q items exhibited strong invariance, meaning that item loadings and item means were similar across the two groups. The KAS-CM items had limited variability, with most respondents indicating high communication levels, and the invariance analysis was done on binary versions of the items. These had metric invariance (loadings the same over groups) but several items violated the strong invariance test. In both groups, the SDM-Q had high internal consistency, whereas the KAS-CM was only adequate. These findings help interpret results for individual patients, taking into account cultural and linguistic differences in how patients perceive SDM and patient-provider communication. PMID:27537002

Psychometrics of shared decision making and communication as patient centered measures for two language groups.

PubMed

Alvarez, Kiara; Wang, Ye; Alegria, Margarita; Ault-Brutus, Andrea; Ramanayake, Natasha; Yeh, Yi-Hui; Jeffries, Julia R; Shrout, Patrick E

2016-09-01

Shared decision making (SDM) and effective patient-provider communication are key and interrelated elements of patient-centered care that impact health and behavioral health outcomes. Measurement of SDM and communication from the patient's perspective is necessary in order to ensure that health care systems and individual providers are responsive to patient views. However, there is a void of research addressing the psychometric properties of these measures with diverse patients, including non-English speakers, and in the context of behavioral health encounters. This study evaluated the psychometric properties of 2 patient-centered outcome measures, the Shared Decision-Making Questionnaire-9 (SDM-Q) and the Kim Alliance Scale-Communication subscale (KAS-CM), in a sample of 239 English and Spanish-speaking behavioral health patients. One dominant factor was found for each scale and this structure was used to examine whether there was measurement invariance across the 2 language groups. One SDM-Q item was inconsistent with the configural invariance comparison and was removed. The remaining SDM-Q items exhibited strong invariance, meaning that item loadings and item means were similar across the 2 groups. The KAS-CM items had limited variability, with most respondents indicating high communication levels, and the invariance analysis was done on binary versions of the items. These had metric invariance (loadings the same over groups) but several items violated the strong invariance test. In both groups, the SDM-Q had high internal consistency, whereas the KAS-CM was only adequate. These findings help interpret results for individual patients, taking into account cultural and linguistic differences in how patients perceive SDM and patient-provider communication. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Preoperative Patellofemoral Chondromalacia is Not a Contraindication for Fixed-Bearing Medial Unicompartmental Knee Arthroplasty.

PubMed

Adams, Alexander J; Kazarian, Gregory S; Lonner, Jess H

2017-06-01

Patellofemoral chondromalacia (PFCM) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA), but there is limited data assessing PFCM's impact on the results of fixed-bearing UKA. Our objective was to assess the impact of medial patellar and/or medial trochlear PFCM on overall and patellofemoral-specific 2-year outcomes after fixed-bearing medial UKA. Intraoperative notes defined the presence and location of PFCM during fixed bearing medial UKA. Outcome measures included the New Knee Society Score (NKSS), Kneeling Ability Score (KAS) and Forgotten Joint Score (FJS-12). Thirty-one knees with PFCM (PFCM group), and 52 knees without PFCM (N-PFCM group) were included for analysis. Mann-Whitney U tests assessed the statistical significance of observed differences, and a Bonferroni correction was applied, adjusting threshold for significance to P = .005. At minimum follow-up of 2 years, no statistical differences were detected between the N-PFCM and PFCM groups in the postoperative NKSS (159 vs 157, P = .731), preoperative to postoperative NKSS change (P = .447), FJS-12 (70.5 vs 67.6, P = .471), or KAS (71% vs 65%, P = .217). Patients with isolated patellar chondromalacia (n = 13) demonstrated trends toward worse outcomes according to NKSS (147, P = .198), FJS-12 (58, P = .094), and KAS (46%, P = .018), but were statistically insignificant. No failures occurred in either group. Functional outcomes of fixed-bearing medial UKA are not adversely impacted by the presence of PFCM involving the medial patellar facet and/or medial or central trochlea. Further follow-up is needed to determine longer-term implications of fixed-bearing medial UKA in patients with PFCM. Copyright © 2017 Elsevier Inc. All rights reserved.

Rutile solubility and titanium coordination in silicate melts

NASA Astrophysics Data System (ADS)

Dickinson, James E., Jr.; Hess, Paul C.

1985-11-01

The solubility of rutile has been determined in a series of compositions in the K 2O-Al 2O 3-SiO 2 system ( K ∗ = K 2O /(K 2O + Al 2O 3) = 0.38-0.90), and the CaO-Al 2O 3-SiO 2 system ( C ∗ = CaO/(CaO + Al 2O 3) = 0.47-0.59 ). Isothermal results in the KAS system at 1325°C, 1400°C, and 1475°C show rutile solubility to be a strong function of the K ∗ ratio. For example, at 1475°C the amount of TiO 2 required for rutile saturation varies from 9.5 wt% ( K ∗ = 0.38 ) to 11.5 wt% ( K ∗ = 0.48 ) to 41.2 wt% ( K ∗ = 0.90 ). In the CAS system at 1475°C, rutile solubility is not a strong function of C ∗. The amount of TiO 2 required for saturation varies from 14 wt% ( C ∗ = 0.48 ) to 16.2 wt% ( C ∗ = 0.59 ). The solubility changes in KAS melts are interpreted to be due to the formation of strong complexes between Ti and K + in excess of that needed to charge balance Al 3+. The suggested stoichiometry of this complex is K 2Ti 2O 5 or K 2Ti 3O 7. In CAS melts, the data suggest that Ca 2+ in excess of A1 3+ is not as effective at complexing with Ti as is K +. The greater solubility of rutile in CAS melts when C ∗ is less than 0.54 compared to KAS melts of equal K ∗ ratio results primarily from competition between Ti and Al for complexing cations (Ca vs. K). TiK β x-ray emission spectra of KAS glasses ( K ∗ = 0.43-0.60 ) with 7 mole% added TiO 2, rutile, and Ba 2TiO 4, demonstrate that the average Ti-O bond length in these glasses is equal to that of rutile rather than Ba 2TiO 4, implying that Ti in these compositions is 6-fold rather than 4-fold coordinated. Re-examination of published spectroscopic data in light of these results and the solubility data, suggests that the 6-fold coordination polyhedron of Ti is highly distorted, with at least one Ti-O bond grossly undersatisfied in terms of Pauling's rules.

10 CFR 26.29 - Training.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Training. 26.29 Section 26.29 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Program Elements § 26.29 Training. (a) Training content. Licensees and other entities shall ensure that the individuals who are subject to this subpart have the following KAs...

10 CFR 26.29 - Training.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Training. 26.29 Section 26.29 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Program Elements § 26.29 Training. (a) Training content. Licensees and other entities shall ensure that the individuals who are subject to this subpart have the following KAs...

10 CFR 26.29 - Training.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Training. 26.29 Section 26.29 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Program Elements § 26.29 Training. (a) Training content. Licensees and other entities shall ensure that the individuals who are subject to this subpart have the following KAs...

10 CFR 26.29 - Training.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Training. 26.29 Section 26.29 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Program Elements § 26.29 Training. (a) Training content. Licensees and other entities shall ensure that the individuals who are subject to this subpart have the following KAs...

10 CFR 26.29 - Training.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Training. 26.29 Section 26.29 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Program Elements § 26.29 Training. (a) Training content. Licensees and other entities shall ensure that the individuals who are subject to this subpart have the following KAs...

Population Genetics Study of Isoniazid Resistance Mutations and Evolution of Multidrug-Resistant Mycobacterium tuberculosis†

PubMed Central

Hazbón, Manzour Hernando; Brimacombe, Michael; Bobadilla del Valle, Miriam; Cavatore, Magali; Guerrero, Marta Inírida; Varma-Basil, Mandira; Billman-Jacobe, Helen; Lavender, Caroline; Fyfe, Janet; García-García, Lourdes; León, Clara Inés; Bose, Mridula; Chaves, Fernando; Murray, Megan; Eisenach, Kathleen D.; Sifuentes-Osornio, José; Cave, M. Donald; Ponce de León, Alfredo; Alland, David

2006-01-01

The molecular basis for isoniazid resistance in Mycobacterium tuberculosis is complex. Putative isoniazid resistance mutations have been identified in katG, ahpC, inhA, kasA, and ndh. However, small sample sizes and related potential biases in sample selection have precluded the development of statistically valid and significant population genetic analyses of clinical isoniazid resistance. We present the first large-scale analysis of 240 alleles previously associated with isoniazid resistance in a diverse set of 608 isoniazid-susceptible and 403 isoniazid-resistant clinical M. tuberculosis isolates. We detected 12 mutant alleles in isoniazid-susceptible isolates, suggesting that these alleles are not involved in isoniazid resistance. However, mutations in katG, ahpC, and inhA were strongly associated with isoniazid resistance, while kasA mutations were associated with isoniazid susceptibility. Remarkably, the distribution of isoniazid resistance-associated mutations was different in isoniazid-monoresistant isolates from that in multidrug-resistant isolates, with significantly fewer isoniazid resistance mutations in the isoniazid-monoresistant group. Mutations in katG315 were significantly more common in the multidrug-resistant isolates. Conversely, mutations in the inhA promoter were significantly more common in isoniazid-monoresistant isolates. We tested for interactions among mutations and resistance to different drugs. Mutations in katG, ahpC, and inhA were associated with rifampin resistance, but only katG315 mutations were associated with ethambutol resistance. There was also a significant inverse association between katG315 mutations and mutations in ahpC or inhA and between mutations in kasA and mutations in ahpC. Our results suggest that isoniazid resistance and the evolution of multidrug-resistant strains are complex dynamic processes that may be influenced by interactions between genes and drug-resistant phenotypes. PMID:16870753

Dihydrolipoamide dehydrogenase-Lpd (Rv0462)-specific T cell recall responses are higher in healthy household contacts of TB: a novel immunodominant antigen from M. tuberculosis.

PubMed

Devasundaram, Santhi; Raja, Alamelu

2017-07-01

The partial effectiveness against pulmonary tuberculosis (PTB), displayed by the existing tuberculosis (TB) vaccine, bacillus Calmette-Guérin (BCG), highlights the need for novel vaccines to replace or improve BCG. In TB immunology, antigen-specific cellular immune response is frequently considered indispensable. Latency-associated antigens are intriguing as targets for TB vaccine development. The mycobacterial protein, dihydrolipoamide dehydrogenase (Lpd; Rv0462), the third enzyme of the pyruvate dehydrogenase (PDH) complex, facilitates Mycobacterium tuberculosis to resist host reactive nitrogen intermediates. Multicolor flow cytometry analysis of whole-blood cultures showed higher Lpd-specific Th1 recall response (IFN-γ, TNF-α, and IL-2; P = 0.0006) and memory CD4 + and CD8 + T cells (CCR7 + CD45RA - and CCR7 - CD45RA - ) in healthy household contacts (HHC) of TB ( P < 0.0001), which is comparable with or higher than the standard antigens, ESAT-6 and CFP-10. The frequency of Lpd-specific multifunctional T cells was higher in HHC compared with PTB patients. However, there is no significant statistical correlation. Regulatory T cell (T reg ) analysis of HHCs and active TB patients demonstrated very low Lpd-specific CD4 + T regs relative to ESAT-6 and CFP-10. Our study demonstrates that the Lpd antigen induces a strong cellular immune response in healthy mycobacteria-infected individuals. In consideration of this population having demonstrated immunologic protection against active TB disease development, our data are encouraging about the possible use of Lpd as a target for further TB subunit vaccine development. © Society for Leukocyte Biology.

Evaluation of the Uniform Field Distortions Produced by a Toroidal Dielectric Body / Novērtējums Viendabīga Elektriskā Lauka Izkropļojumiem, Kurus Rada Toroīda Formas Dielektrisks Ķermenis

NASA Astrophysics Data System (ADS)

Krasnitsky, Y. A.; Popov, A. E.; Kalnacs, A.

2015-08-01

Distortions of the structure of a uniform electric field when a dielectric body with a toroidal shape is placed in it are considered in the quasi-static approximation. The rate of distortion is proposed to estimate through the effective permittivity of toroid determined by solving the corresponding boundary value problem. Some numerical estimates obtained using specially developed software in the language of Matlab are given. Darbā apskatīts kvazi-statisks tuvinājums viendabīga elektriskā lauka izkropļojumiem gadījumos, kad tajā tiek ievietots dielektrisks toroīda formas ķermenis. Izkropļojumu apmēru tiek piedāvāts novērtēt ar toroīda efektīvo caurlaidību, kas tiek noteikta, atrisinot atbilstošo robežvērtību uzdevumu. Tiek doti skaitliski novērtējumi, kas iegūti, lietojot speciāli valodā Matlab izstrādātu programmatūru.

Pyrolysis of Musa balbisiana flower petal using thermogravimetric studies.

PubMed

Sriram, Aswin; Swaminathan, Ganapathiraman

2018-05-11

In the present study, thermogravimetric analysis of Musa balbisiana flower petal was carried out to study the degradation behaviour and the kinetics in the pyrolytic reaction. The pyrolysis was carried out in the temperature range of 35-900 °C at different heating rates of 5, 10 and 20 °C/min. The kinetics was investigated using different models like Kissinger-Akahira-Sunose (KAS), Flynn-Ozawa-Wall (FOW), Friedman and Broido's plot. The average E a values determined by KAS, FOW and Friedman methods were 137.94, 136.76 and 133.36 kJ/mol respectively. Coats-Redfern method was utilized to determine the pre-exponential factors and the reaction order of the pyrolysis. For the conversion rates 0.1 and 0.2, both Valensi and Ginstling diffusion models were found out to be appropriate for the solid state reaction mechanism. The HHV of Musa balbisiana flower petal was 16.35 MJ/kg, suggested as a potential bio-feedstock energy source from agro-waste. Copyright © 2018. Published by Elsevier Ltd.

Characteristics and kinetics study of simultaneous pyrolysis of microalgae Chlorella vulgaris, wood and polypropylene through TGA.

PubMed

Azizi, Kolsoom; Keshavarz Moraveji, Mostafa; Abedini Najafabadi, Hamed

2017-11-01

Thermal decomposition behavior and kinetics of microalgae Chlorella vulgaris, wood and polypropylene were investigated using thermogravimetric analysis (TGA). Experiments were carried out at heating rates of 10, 20 and 40°C/min from ambient temperature to 600°C. The results show that pyrolysis process of C. vulgaris and wood can be divided into three stages while pyrolysis of polypropylene occurs almost totally in one step. It is shown that wood can delay the pyrolysis of microalgae while microalgae can accelerate the pyrolysis of wood. The existence of polymer during the pyrolysis of microalgae or wood will lead to two divided groups of peaks in DTG curve of mixtures. The results showed that interaction is inhibitive rather than synergistic during the decomposition process of materials. Kinetics of process is studied by the Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The average E values obtained from FWO and KAS methods were 131.228 and 142.678kJ/mol, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

PubMed

Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

2015-07-01

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Limitations of Using IL-17A and IFN-γ-Induced Protein 10 to Detect Bovine Tuberculosis

PubMed Central

Xin, Ting; Gao, Xintao; Yang, Hongjun; Li, Pingjun; Liang, Qianqian; Hou, Shaohua; Sui, Xiukun; Guo, Xiaoyu; Yuan, Weifeng; Zhu, Hongfei; Ding, Jiabo; Jia, Hong

2018-01-01

Bovine tuberculosis (bTB) is primarily caused by infection with Mycobacterium bovis, which belongs to the Mycobacterium tuberculosis complex. The airborne route is considered the most common for transmission of M. bovis, and more than 15% of cattle with bTB shed the Mycobacterium, which can be detect by nested PCR to amplify mycobacterial mpb70 from a nasal swab from a cow. To screen for cytokines fostering early and accurate detection of bTB, peripheral blood mononuclear cells were isolated from naturally M. bovis-infected, experimentally M. bovis 68002-infected, and uninfected cattle, then these cells were stimulated by PPD-B, CFP-10-ESAT-6 (CE), or phosphate-buffered saline (PBS) for 6 h. The levels of interferon gamma (IFN-γ), IFN-γ-induced protein 10 (IP-10), IL-6, IL-12, IL-17A, and tumor necrosis factor alpha mRNA were measured using real-time PCR. To explore the cytokines associated with different periods of M. bovis infection, cattle were divided into three groups: PCR-positive, PCR-negative, and uninfected using the tuberculin skin test, CFP-10/ESAT-6/TB10.4 protein cocktail-based skin test, IFN-γ release assay (IGRA), CFP-10/ESAT-6 (CE)-based IGRA, and nested PCR. The expression of IP-10, IL-17A, and IFN-γ proteins induced by PPD-B, CE, or PBS was detected by ELISA. The results showed that levels of PPD-B-stimulated IL-17A and IP-10 (mRNA and protein), and CE-induced IP-10 (mRNA and protein) were significantly higher in cattle naturally or experimentally infected with M. bovis than in those that were uninfected. The levels of PPD-B- or CE-induced IL-17A and IP-10 (protein) could be used to differentiate M. bovis-infected calves from uninfected ones for 6 to 30 weeks post-infection, whereas PPD-B- and CE-induced IP-10 and IL-17A mRNA expression could be used to differentiate M. bovis-infected calves from uninfected ones between 6 and 58 weeks post-infection. However, CE-induced IL-17A (protein) was not a reliable indicator of M. bovis infection

CTC Sentinel. Volume 5, Issue 3

DTIC Science & Technology

2012-03-01

planning or execution of the July 22 attacks.” 9 to his mother’s home to upload the movie trailer on YouTube. He claims that he wrote the last message...Dahdah (whose real name is Imad Eddin Barakat Yar- kas) became the cell leader in 1995 once Saleh moved to Peshawar to help in al-Qa`ida’s reception of

Citizen Airman Magazine > Home

Science.gov Websites

Past Issues Social Media Twitter Logo Youth aviation event sparks new energy - https://t.co/TJG3nKAs4D ! Just getting things setup! Facebook 76 Like Us Twitter 278 Follow Us YouTube Blog RSS Air Force Social Media Guide (PDF) USAF Social Media Sites About AFRC AFR Mission Briefing Mission Briefing AFR Snapshot

The multistage vaccine H56 boosts the effects of BCG to protect cynomolgus macaques against active tuberculosis and reactivation of latent Mycobacterium tuberculosis infection

PubMed Central

Lin, Philana Ling; Dietrich, Jes; Tan, Esterlina; Abalos, Rodolfo M.; Burgos, Jasmin; Bigbee, Carolyn; Bigbee, Matthew; Milk, Leslie; Gideon, Hannah P.; Rodgers, Mark; Cochran, Catherine; Guinn, Kristi M.; Sherman, David R.; Klein, Edwin; Janssen, Christopher; Flynn, JoAnne L.; Andersen, Peter

2011-01-01

It is estimated that one-third of the world’s population is infected with Mycobacterium tuberculosis. Infection typically remains latent, but it can reactivate to cause clinical disease. The only vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG), is largely ineffective, and ways to enhance its efficacy are being developed. Of note, the candidate booster vaccines currently under clinical development have been designed to improve BCG efficacy but not prevent reactivation of latent infection. Here, we demonstrate that administering a multistage vaccine that we term H56 in the adjuvant IC31 as a boost to vaccination with BCG delays and reduces clinical disease in cynomolgus macaques challenged with M. tuberculosis and prevents reactivation of latent infection. H56 contains Ag85B and ESAT-6, which are two of the M. tuberculosis antigens secreted in the acute phase of infection, and the nutrient stress–induced antigen Rv2660c. Boosting with H56/IC31 resulted in efficient containment of M. tuberculosis infection and reduced rates of clinical disease, as measured by clinical parameters, inflammatory markers, and improved survival of the animals compared with BCG alone. Boosted animals showed reduced pulmonary pathology and extrapulmonary dissemination, and protection correlated with a strong recall response against ESAT-6 and Rv2660c. Importantly, BCG/H56-vaccinated monkeys did not reactivate latent infection after treatment with anti-TNF antibody. Our results indicate that H56/IC31 boosting is able to control late-stage infection with M. tuberculosis and contain latent tuberculosis, providing a rationale for the clinical development of H56. PMID:22133873

Computational Tools for Interpreting Ion Channel pH-Dependence.

PubMed

Sazanavets, Ivan; Warwicker, Jim

2015-01-01

Activity in many biological systems is mediated by pH, involving proton titratable groups with pKas in the relevant pH range. Experimental analysis of pH-dependence in proteins focusses on particular sidechains, often with mutagenesis of histidine, due to its pKa near to neutral pH. The key question for algorithms that predict pKas is whether they are sufficiently accurate to effectively narrow the search for molecular determinants of pH-dependence. Through analysis of inwardly rectifying potassium (Kir) channels and acid-sensing ion channels (ASICs), mutational effects on pH-dependence are probed, distinguishing between groups described as pH-coupled or pH-sensor. Whereas mutation can lead to a shift in transition pH between open and closed forms for either type of group, only for pH-sensor groups does mutation modulate the amplitude of the transition. It is shown that a hybrid Finite Difference Poisson-Boltzmann (FDPB) - Debye-Hückel continuum electrostatic model can filter mutation candidates, providing enrichment for key pH-coupled and pH-sensor residues in both ASICs and Kir channels, in comparison with application of FDPB alone.

Computational Tools for Interpreting Ion Channel pH-Dependence

PubMed Central

Sazanavets, Ivan; Warwicker, Jim

2015-01-01

Activity in many biological systems is mediated by pH, involving proton titratable groups with pKas in the relevant pH range. Experimental analysis of pH-dependence in proteins focusses on particular sidechains, often with mutagenesis of histidine, due to its pKa near to neutral pH. The key question for algorithms that predict pKas is whether they are sufficiently accurate to effectively narrow the search for molecular determinants of pH-dependence. Through analysis of inwardly rectifying potassium (Kir) channels and acid-sensing ion channels (ASICs), mutational effects on pH-dependence are probed, distinguishing between groups described as pH-coupled or pH-sensor. Whereas mutation can lead to a shift in transition pH between open and closed forms for either type of group, only for pH-sensor groups does mutation modulate the amplitude of the transition. It is shown that a hybrid Finite Difference Poisson-Boltzmann (FDPB) – Debye-Hückel continuum electrostatic model can filter mutation candidates, providing enrichment for key pH-coupled and pH-sensor residues in both ASICs and Kir channels, in comparison with application of FDPB alone. PMID:25915903

Allocating Deceased Donor Kidneys to Candidates with High Panel-Reactive Antibodies.

PubMed

Gebel, Howard M; Kasiske, Bertram L; Gustafson, Sally K; Pyke, Joshua; Shteyn, Eugene; Israni, Ajay K; Bray, Robert A; Snyder, Jon J; Friedewald, John J; Segev, Dorry L

2016-03-07

In December of 2014, the Organ Procurement and Transplant Network implemented a new Kidney Allocation System (KAS) for deceased donor transplant, with increased priority for highly sensitized candidates (calculated panel-reactive antibody [cPRA] >99%). We used a modified version of the new KAS to address issues of access and equity for these candidates. In a simulation, 10,988 deceased donor kidneys transplanted into waitlisted recipients in 2010 were instead allocated to candidates with cPRA≥80% (n=18,004). Each candidate's unacceptable donor HLA antigens had been entered into the allocation system by the transplant center. In simulated match runs, kidneys were allocated sequentially to adult ABO identical or permissible candidates with cPRA 100%, 99%, 98%, etc. to 80%. Allocations were restricted to donor/recipient pairs with negative virtual crossmatches. The simulation indicated that 2111 of 10,988 kidneys (19.2%) would have been allocated to patients with cPRA 100% versus 74 of 10,988 (0.7%) that were actually transplanted. Of cPRA 100% candidates, 74% were predicted to be compatible with an average of six deceased donors; the remaining 26% seemed to be incompatible with every deceased donor organ that entered the system. Of kidneys actually allocated to cPRA 100% candidates in 2010, 66% (49 of 74) were six-antigen HLA matched/zero-antigen mismatched (HLA-A, -B, and -DR) with their recipients versus only 11% (237 of 2111) in the simulation. The simulation predicted that 10,356 of 14,433 (72%) candidates with cPRA 90%-100% could be allocated an organ compared with 7.3% who actually underwent transplant. Data in this simulation are consistent with early results of the new KAS; specifically, nearly 20% of deceased donor kidneys were (virtually) compatible with cPRA 100% candidates. Although most of these candidates were predicted to be compatible with multiple donors, approximately one-quarter are unlikely to receive a single offer. Copyright © 2016 by the

Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

NASA Astrophysics Data System (ADS)

Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

2016-11-01

The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

Distributed database kriging for adaptive sampling (D²KAS)

DOE PAGES

Roehm, Dominic; Pavel, Robert S.; Barros, Kipton; ...

2015-03-18

We present an adaptive sampling method supplemented by a distributed database and a prediction method for multiscale simulations using the Heterogeneous Multiscale Method. A finite-volume scheme integrates the macro-scale conservation laws for elastodynamics, which are closed by momentum and energy fluxes evaluated at the micro-scale. In the original approach, molecular dynamics (MD) simulations are launched for every macro-scale volume element. Our adaptive sampling scheme replaces a large fraction of costly micro-scale MD simulations with fast table lookup and prediction. The cloud database Redis provides the plain table lookup, and with locality aware hashing we gather input data for our predictionmore » scheme. For the latter we use kriging, which estimates an unknown value and its uncertainty (error) at a specific location in parameter space by using weighted averages of the neighboring points. We find that our adaptive scheme significantly improves simulation performance by a factor of 2.5 to 25, while retaining high accuracy for various choices of the algorithm parameters.« less

Magnetic Resonance Spectroscopy: An Objectives Technique for the Quantification of Prostate Cancer Pathologies

DTIC Science & Technology

2006-02-01

5d. PROJECT NUMBER Leo L. Cheng, Ph.D. 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S...Above all we were extremely pleased that our results reported in this article were selected to be included in the Department of Defense, United ...Astra- kas LG, Zarifi MK, Scott RM, Anthony DC, Gonzalez RG, Black PM. Biochemical characterization of pediatric brain tumors by using in vivo and

Evolutionary landscape of the Mycobacterium tuberculosis complex from the viewpoint of PhoPR: implications for virulence regulation and application to vaccine development.

PubMed

Broset, Esther; Martín, Carlos; Gonzalo-Asensio, Jesús

2015-10-20

Different members of the Mycobacterium genus have evolved to cause tuberculosis in diverse human populations and in a variety of animal species. Our cumulative knowledge of mycobacterial genomes indicates that mutations in the PhoPR two-component virulence system were acquired not only during the natural evolution of mycobacterial species but also during in vitro subculture, which has given rise to the attenuated reference strain H37Ra or to different daughter strains of Mycobacterium bovis BCG. PhoPR is a well-known regulator of pathogenic phenotypes, including secretion of the virulence factor ESAT-6, biosynthesis of acyltrehalose-based lipids, and modulation of antigen export, in members of the Mycobacterium tuberculosis complex (MTBC). Evolutionarily conserved polymorphisms in PhoPR from Mycobacterium africanum, M. bovis, or M. tuberculosis H37Ra result in loss of functional phenotypes. Interestingly, some members of the MTBC have acquired compensatory mutations to counteract these polymorphisms and, probably, to maintain their pathogenic potential. Some of these compensatory mutations include the insertion of the IS6110 element upstream from phoPR in a particular M. bovis strain that is able to transmit between humans or polymorphisms in M. africanum and M. bovis that affect the regulatory region of the espACD operon, allowing PhoPR-independent ESAT-6 secretion. This review highlights the increasing knowledge of the significance of PhoPR in the evolution of the MTBC and its potential application in the construction of new attenuated vaccines based on phoPR inactivation. In this context, the live attenuated vaccine MTBVAC, based on a phoP fadD26 deletion mutant of M. tuberculosis, is the first vaccine of this kind to successfully enter into clinical development, representing a historic milestone in the field of human vaccinology. Copyright © 2015 Broset et al.

Evolutionary Landscape of the Mycobacterium tuberculosis Complex from the Viewpoint of PhoPR: Implications for Virulence Regulation and Application to Vaccine Development

PubMed Central

Broset, Esther

2015-01-01

ABSTRACT Different members of the Mycobacterium genus have evolved to cause tuberculosis in diverse human populations and in a variety of animal species. Our cumulative knowledge of mycobacterial genomes indicates that mutations in the PhoPR two-component virulence system were acquired not only during the natural evolution of mycobacterial species but also during in vitro subculture, which has given rise to the attenuated reference strain H37Ra or to different daughter strains of Mycobacterium bovis BCG. PhoPR is a well-known regulator of pathogenic phenotypes, including secretion of the virulence factor ESAT-6, biosynthesis of acyltrehalose-based lipids, and modulation of antigen export, in members of the Mycobacterium tuberculosis complex (MTBC). Evolutionarily conserved polymorphisms in PhoPR from Mycobacterium africanum, M. bovis, or M. tuberculosis H37Ra result in loss of functional phenotypes. Interestingly, some members of the MTBC have acquired compensatory mutations to counteract these polymorphisms and, probably, to maintain their pathogenic potential. Some of these compensatory mutations include the insertion of the IS6110 element upstream from phoPR in a particular M. bovis strain that is able to transmit between humans or polymorphisms in M. africanum and M. bovis that affect the regulatory region of the espACD operon, allowing PhoPR-independent ESAT-6 secretion. This review highlights the increasing knowledge of the significance of PhoPR in the evolution of the MTBC and its potential application in the construction of new attenuated vaccines based on phoPR inactivation. In this context, the live attenuated vaccine MTBVAC, based on a phoP fadD26 deletion mutant of M. tuberculosis, is the first vaccine of this kind to successfully enter into clinical development, representing a historic milestone in the field of human vaccinology. PMID:26489860

Responses to diagnostic tests for bovine tuberculosis in dairy and non-dairy cattle naturally exposed to Mycobacterium bovis in Great Britain.

PubMed

Downs, S H; Broughan, J M; Goodchild, A V; Upton, P A; Durr, P A

2016-10-01

Field surveillance of British cattle using the single intradermal comparative cervical tuberculin (SICCT) test shows a higher incidence rate of bovine tuberculosis (bTB) in dairy compared to beef herds, but a lower probability of post-mortem examination confirmed (PMC) Mycobacterium bovis infection in dairy herds. A cross-sectional study was conducted to compare animal level differences in bTB detection between dairy and non-dairy cattle in Great Britain. During the period from 2002 to 2005, 200 (41% dairy) reactors in the SICCT test (standard interpretation) were randomly selected, and 200 in-contact cattle (43% dairy) were purposively selected from bTB-infected herds. Interferon (IFN)-γ responses in blood to bovine and avian purified protein derivative (PPD), and early secretory antigen target 6 kDa and culture filtrate protein 10 (ESAT-6/CFP10), were measured. The post-mortem examination included gross pathological examination, mycobacterial culture and histopathology. The proportions of cattle positive to ESAT6/CFP10 were 26% (95% confidence interval, CI, 15-39%) in dairy reactors and 62% (95% CI 51-72%) in non-dairy reactors (P <0.001). PMC risk was 34% (95% CI 24-45%) in dairy reactors and 69% (95% CI 60-78%) in non-dairy reactors (P <0.001). The odds ratio for PMC risk in dairy reactors compared to non-dairy reactors, after controlling for bTB prevalence, herd size and SICCT test response, was 0.27 (95% CI 0.14-0.53; P <0.001). In surveillance data, adjusted animal level PMC risks were lower for dairy reactors than for beef reactors aged >2 years (P <0.001). Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

The ΔfbpA attenuated candidate vaccine from Mycobacterium tuberculosis, H37Rv primes for a stronger T-bet dependent Th1 immunity in mice.

PubMed

Roche, Cherie M; Smith, Amanda; Lindsey, Devin R; Meher, Akshay; Schluns, Kimberly; Arora, Ashish; Armitige, Lisa Y; Jagannath, Chinnaswamy

2011-12-01

The ΔfbpA candidate vaccine derived from Mycobacterium tuberculosis (H37Rv) (Mtb) protects mice better than BCG against tuberculosis, and we investigated the hypothesis that ΔfbpA may induce a stronger Th1 immunity. Since T-bet transcription factor regulates Th1 immunity, mice infected with ΔfbpA, BCG vaccine and related mycobacteria were analyzed for T-bet positive T cells. Mouse dendritic cells (DCs) or macrophages were also pulsed with excretory-secreted antigens (ES; Antigen-85B, ESAT-6 and CFP10) and cocultured with T cells from immunized or naïve mice and tested for in vitro induction of T-bet and IFN-γ. In both models, ΔfbpA mutant induced a stronger response of T-bet(+)CD4 T cells, which correlated with an increased expansion of IFN-γ(+)CD4 T cells in vivo and in vitro. When DCs pulsed with ES antigens were allowed to stimulate T cells, ESAT-6 and CFP-10 failed to induce a recall expansion of T-bet(+)IFN-γ(+)CD4 T cells from BCG vaccinated mice. Thus, deletion of RD1 in BCG seems to reduce its ability to induce T-bet and induce stronger Th1 immunity. Finally, mice were vaccinated with ΔfbpA and BCG and challenged with virulent Mtb for evaluation of protection and T cell expansion. ΔfbpA vaccinated mice showed a rapid and stronger expansion of CD4(+)CXCR3(+) IFN-γ(+) T cells in the lungs of Mtb challenged mice, compared to those which had BCG vaccine. ΔfbpA immunized mice also showed a better decline of the Mtb bacterial counts of the lungs. Mtb derived ΔfbpA candidate vaccine therefore induces qualitatively better T-bet dependent Th1 immunity than BCG vaccine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hierarchy Low CD4+/CD8+ T-Cell Counts and IFN-γ Responses in HIV-1+ Individuals Correlate with Active TB and/or M.tb Co-Infection.

PubMed

Shao, Lingyun; Zhang, Xinyun; Gao, Yan; Xu, Yunya; Zhang, Shu; Yu, Shenglei; Weng, Xinhua; Shen, Hongbo; Chen, Zheng W; Jiang, Weimin; Zhang, Wenhong

2016-01-01

Detailed studies of correlation between HIV-M.tb co-infection and hierarchy declines of CD8+/CD4+ T-cell counts and IFN-γ responses have not been done. We conducted case-control studies to address this issue. 164 HIV-1-infected individuals comprised of HIV-1+ATB, HIV-1+LTB and HIV-1+TB- groups were evaluated. Immune phenotyping and complete blood count (CBC) were employed to measure CD4+ and CD8+ T-cell counts; T.SPOT.TB and intracellular cytokine staining (ICS) were utilized to detect ESAT6, CFP10 or PPD-specific IFN-γ responses. There were significant differences in median CD4+ T-cell counts between HIV-1+ATB (164/μL), HIV-1+LTB (447/μL) and HIV-1+TB- (329/μL) groups. Hierarchy low CD4+ T-cell counts (<200/μL, 200-500/μL, >500/μL) were correlated significantly with active TB but not M.tb co-infection. Interestingly, hierarchy low CD8+ T-cell counts were not only associated significantly with active TB but also with M.tb co-infection (P<0.001). Immunologically, HIV-1+ATB group showed significantly lower numbers of ESAT-6-/CFP-10-specific IFN-γ+ T cells than HIV-1+LTB group. Consistently, PPD-specific IFN-γ+CD4+/CD8+ T effector cells in HIV-1+ATB group were significantly lower than those in HIV-1+LTB group (P<0.001). Hierarchy low CD8+ T-cell counts and effector function in HIV-1-infected individuals are correlated with both M.tb co-infection and active TB. Hierarchy low CD4+ T-cell counts and Th1 effector function in HIV-1+ individuals are associated with increased frequencies of active TB, but not M.tb co-infection.

Improving the Immunogenicity of the Mycobacterium bovis BCG Vaccine by Non-Genetic Bacterial Surface Decoration Using the Avidin-Biotin System.

PubMed

Liao, Ting-Yu Angela; Lau, Alice; Joseph, Sunil; Hytönen, Vesa; Hmama, Zakaria

2015-01-01

Current strategies to improve the current BCG vaccine attempt to over-express genes encoding specific M. tuberculosis (Mtb) antigens and/or regulators of antigen presentation function, which indeed have the potential to reshape BCG in many ways. However, these approaches often face serious difficulties, in particular the efficiency and stability of gene expression via nucleic acid complementation and safety concerns associated with the introduction of exogenous DNA. As an alternative, we developed a novel non-genetic approach for rapid and efficient display of exogenous proteins on bacterial cell surface. The technology involves expression of proteins of interest in fusion with a mutant version of monomeric avidin that has the feature of reversible binding to biotin. Fusion proteins are then used to decorate the surface of biotinylated BCG. Surface coating of BCG with recombinant proteins was highly reproducible and stable. It also resisted to the freeze-drying shock routinely used in manufacturing conventional BCG. Modifications of BCG surface did not affect its growth in culture media neither its survival within the host cell. Macrophages phagocytized coated BCG bacteria, which efficiently delivered their surface cargo of avidin fusion proteins to MHC class I and class II antigen presentation compartments. Thereafter, chimeric proteins corresponding to a surrogate antigen derived from ovalbumin and the Mtb specific ESAT6 antigen were generated and tested for immunogenicity in vaccinated mice. We found that BCG displaying ovalbumin antigen induces an immune response with a magnitude similar to that induced by BCG genetically expressing the same surrogate antigen. We also found that BCG decorated with Mtb specific antigen ESAT6 successfully induces the expansion of specific T cell responses. This novel technology, therefore, represents a practical and effective alternative to DNA-based gene expression for upgrading the current BCG vaccine.

Molecular cloning and characterization of two β-ketoacyl-acyl carrier protein synthase I genes from Jatropha curcas L.

PubMed

Xiong, Wangdan; Wei, Qian; Wu, Pingzhi; Zhang, Sheng; Li, Jun; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

2017-07-01

The β-ketoacyl-acyl carrier protein synthase I (KASI) is involved in de novo fatty acid biosynthesis in many organisms. Two putative KASI genes, JcKASI-1 and JcKASI-2, were isolated from Jatropha curcas. The deduced amino acid sequences of JcKASI-1 and JcKASI-2 exhibit around 83.8% and 72.5% sequence identities with AtKASI, respectively, and both contain conserved Cys-His-Lys-His-Phe catalytic active sites. Phylogenetic analysis indicated that JcKASI-2 belongs to a clade with several KASI proteins from dicotyledonous plants. Both JcKASI genes were expressed in multiple tissues, most strongly in filling stage seeds of J. curcas. Additionally, the JcKASI-1 and JcKASI-2 proteins were both localized to the plastids. Expressing JcKASI-1 in the Arabidopsis kasI mutant rescued the mutant's phenotype and restored the fatty acid composition and oil content in seeds to wild-type, but expressing JcKASI-2 in the Arabidopsis kasI mutant resulted in only partial rescue. This implies that JcKASI-1 and JcKASI-2 exhibit partial functional redundancy and KASI genes play a universal role in regulating fatty acid biosynthesis, growth, and development in plants. Copyright © 2017 Elsevier GmbH. All rights reserved.

Pyrolysis kinetics and thermal behavior of waste sawdust biomass using thermogravimetric analysis.

PubMed

Mishra, Ranjeet Kumar; Mohanty, Kaustubha

2018-03-01

The present study reports pyrolysis behavior of three waste biomass using thermogravimetric analysis to determine kinetic parameters at five different heating rates. Physiochemical characterization confirmed that these biomass have the potential for fuel and energy production. Pyrolysis experiments were carried out at five different heating rates (5-25 °C min -1 ). Five model-free methods such as Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Friedman, Coats-Redfern, and distributed activation energy (DAEM) were used to calculate the kinetic parameters. The activation energy was found to be 171.66 kJ mol -1 , 148.44 kJ mol -1 , and 171.24 kJ mol -1 from KAS model; 179.29 kJ mol -1 , 156.58 kJ mol -1 , and 179.47 kJ mol -1 from OFW model; 168.58 kJ mol -1 , 181.53 kJ mol -1 , and 184.61 kJ mol -1 from Friedman model; and 206.62 kJ mol -1 , 171.63 kJ mol -1 , and 160.45 kJ mol -1 from DAEM model for PW, SW, AN biomass respectively. The calculated kinetic parameters are in good agreement with other reported biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neomycin resistance as a selectable marker in Methanococcus maripaludis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Argyle, J.L.; Leigh, J.A.; Tumbula, D.L.

1996-11-01

The authors cloned the aminoglycoside phosphotransferase genes APH3{prime}I and APH3{prime}II between the Methanococcus voltae methyl reductase promoter and terminator in a plasmid containing a fragment of Methanococcus maripaludis chromosomal DNA. The resulting plasmids encoding neomycin resistance transformed M. maripaludis at frequencies similar to those observed for pKAS102 encoding puromycin resistance. The antibiotic geneticin was not inhibitory to M. maripaludis. 22 refs., 3 figs., 3 tabs.

Enhanced metabolic effect of erythropoietin and keto acids in CRF patients on low-protein diet: Czech multicenter study.

PubMed

Teplan, Vladimír; Schück, Otto; Knotek, Antonín; Hajný, Jan; Horácková, Miroslava; Kvapil, Milan

2003-03-01

Our study is designed to establish whether supplementation with erythropoietin (EPO) exerts additional beneficial metabolic effects in patients with chronic renal failure (CRF) treated with keto acids (KAs) on a low-protein diet (LPD). A long-term, prospective, randomized study was designed to use three therapeutic protocols: (A) EPO plus KAs plus LPD (group I), (B) EPO plus LPD (group II), and (C) LPD (group III). One hundred eighty-six randomly selected patients (90 men, 96 women; age, 22 to 78 years) with a creatinine clearance of 22 to 36 mL/min were monitored at the beginning and at every 6 months for 3 years. During the study period, glomerular filtration rate measured as inulin clearance decreased slightly (from 26.2 +/- 3.4 to 23.4 +/- 4.1 mL/min in group I), 27.4 +/- 4.8 to 20.2 +/- 4.4 mL/min in group II, and 26.8 +/- 3.6 to 17.4 +/- 4.1 mL/min in group III; P < 0.01). Serum urea levels also declined (P < 0.01), more pronouncedly in group I (P < 0.025). In group I, there was a significant increase in levels of leucine (P < 0.01) and albumin (P < 0.01) and a decrease in proteinuria (P < 0.01). Analysis of the lipid spectrum showed a mild, yet significant, decrease in total cholesterol and low-density lipoprotein cholesterol levels (P < 0.025), more pronounced in group I. In group I, there was a decrease in plasma triglyceride levels (from 362.85 +/- 115.05 mg/dL [4.1 +/- 1.3 mmol/L] to values as low as 203.55 +/- 70.80 mg/dL [2.3 +/- 0.8 mmol/L]; P < 0.01), whereas high-density lipoprotein cholesterol levels increased (from 34.75 +/- 7.72 mg/dL [0.9 +/- 0.2 mmol/L] to 46.33 +/- 7.72 mg/dL [1.2 +/- 0.2 mmol/L]; P < 0.025). Mean arterial blood pressure was stable. EPO supplementation in patients with CRF administered KAs potentiates the beneficial effects on metabolism of proteins, amino acids, and lipids. Long-term coadministration of EPO, KA, and LPD was associated with a delay in progression of renal failure and reduction in proteinuria.

Production of a fusion protein consisting of the enterotoxigenic Escherichia coli heat-labile toxin B subunit and a tuberculosis antigen in Arabidopsis thaliana.

PubMed

Rigano, M M; Alvarez, M L; Pinkhasov, J; Jin, Y; Sala, F; Arntzen, C J; Walmsley, A M

2004-02-01

Transgenic plants are potentially safe and inexpensive vehicles to produce and mucosally deliver protective antigens. However, the application of this technology is limited by the poor response of the immune system to non-particulate, subunit vaccines. Co-delivery of therapeutic proteins with carrier proteins could increase the effectiveness of the antigen. This paper reports the ability of transgenic Arabidopsis thaliana plants to produce a fusion protein consisting of the B subunit of the Escherichia coli heat-labile enterotoxin and a 6 kDa tuberculosis antigen, the early secretory antigenic target ESAT-6. Both components of the fusion protein were detected using GM1-ganglioside-dependent enzyme-linked immunosorbant assay. This suggested the fusion protein retained both its native antigenicity and the ability to form pentamers.

Cross-cultural validation of instruments measuring health beliefs about colorectal cancer screening among Korean Americans.

PubMed

Lee, Shin-Young; Lee, Eunice E

2015-02-01

The purpose of this study was to report the instrument modification and validation processes to make existing health belief model scales culturally appropriate for Korean Americans (KAs) regarding colorectal cancer (CRC) screening utilization. Instrument translation, individual interviews using cognitive interviewing, and expert reviews were conducted during the instrument modification phase, and a pilot test and a cross-sectional survey were conducted during the instrument validation phase. Data analyses of the cross-sectional survey included internal consistency and construct validity using exploratory and confirmatory factor analysis. The main issues identified during the instrument modification phase were (a) cultural and linguistic translation issues and (b) newly developed items reflecting Korean cultural barriers. Cross-sectional survey analyses during the instrument validation phase revealed that all scales demonstrate good internal consistency reliability (Cronbach's alpha=.72~.88). Exploratory factor analysis showed that susceptibility and severity loaded on the same factor, which may indicate a threat variable. Items with low factor loadings in the confirmatory factor analysis may relate to (a) lack of knowledge about fecal occult blood testing and (b) multiple dimensions of the subscales. Methodological, sequential processes of instrument modification and validation, including translation, individual interviews, expert reviews, pilot testing and a cross-sectional survey, were provided in this study. The findings indicate that existing instruments need to be examined for CRC screening research involving KAs.

Effect of foliar application of salicylic acid, hydrogen peroxide and a xyloglucan oligosaccharide on capsiate content and gene expression associatedwith capsinoids synthesis in Capsicum annuum L.

PubMed

Zunun-Perez, A Y; Guevara-Figueroa, T; Jimenez-Garcia, S N; Feregrino-Perez, A A; Gautier, F; Guevara-Gonzalez, R G

2017-06-01

Capsinoids are non-pungent analogues of capsaicinoids in pepper (Capsicum spp). The absence of pungency, in addition to their biological activities similar to that of capsaicinoids such as anti-inflammatory, antimicrobial, and antioxidant properties, makes capsinoids an excellent option for increasing use in human and animal nutrition, as well as health and pharmaceutical industries. There are only few sources of pepper producing capsinoids, and one of them (accession 509-45-1), Capsicum annuum L., is a potential source for increasing capsinoids content using strategies as controlled elicitation during plant production in the greenhouse. In this research we evaluated the effect of weekly and one-day-before-harvest foliar applications of hydrogen peroxide, salicylic acid and a xyloglucan oligosaccharide on the concentration of capsiate in fruits of this pepper accession, as well as the gene expression of phenylalanine ammonia-lyase (pal), putative aminotransferase (pamt), capsaicin synthase (at3) and β-keto acyl synthase (kas). Results showed that the two tested concentrations of H2O2 significantly increased capsiate content and gene expression associated with capsaicinoids (pamt, at3 and kas) and the phenylpropanoids (pal) pathways. Plant yield was not affected using this induction strategy. Our results indicated that the pre-harvest and weekly application of hydrogen peroxide and xyloglucan oligosaccharide improved production of capsiate in C. annuum L.

One recognition sequence, seven restriction enzymes, five reaction mechanisms

PubMed Central

Gowers, Darren M.; Bellamy, Stuart R.W.; Halford, Stephen E.

2004-01-01

The diversity of reaction mechanisms employed by Type II restriction enzymes was investigated by analysing the reactions of seven endonucleases at the same DNA sequence. NarI, KasI, Mly113I, SfoI, EgeI, EheI and BbeI cleave DNA at several different positions in the sequence 5′-GGCGCC-3′. Their reactions on plasmids with one or two copies of this sequence revealed five distinct mechanisms. These differ in terms of the number of sites the enzyme binds, and the number of phosphodiester bonds cleaved per turnover. NarI binds two sites, but cleaves only one bond per DNA-binding event. KasI also cuts only one bond per turnover but acts at individual sites, preferring intact to nicked sites. Mly113I cuts both strands of its recognition sites, but shows full activity only when bound to two sites, which are then cleaved concertedly. SfoI, EgeI and EheI cut both strands at individual sites, in the manner historically considered as normal for Type II enzymes. Finally, BbeI displays an absolute requirement for two sites in close physical proximity, which are cleaved concertedly. The range of reaction mechanisms for restriction enzymes is thus larger than commonly imagined, as is the number of enzymes needing two recognition sites. PMID:15226412

Analysis of Host Responses to Mycobacterium tuberculosis Antigens in a Multi-Site Study of Subjects with Different TB and HIV Infection States in Sub-Saharan Africa

PubMed Central

Sutherland, Jayne S.; Lalor, Maeve K.; Black, Gillian F.; Ambrose, Lyn R.; Loxton, Andre G.; Chegou, Novel N.; Kassa, Desta; Mihret, Adane; Howe, Rawleigh; Mayanja-Kizza, Harriet; Gomez, Marie P.; Donkor, Simon; Franken, Kees; Hanekom, Willem; Klein, Michel R.; Parida, Shreemanta K.; Boom, W. Henry; Thiel, Bonnie A.; Crampin, Amelia C.; Ota, Martin; Walzl, Gerhard; Ottenhoff, Tom H. M.; Dockrell, Hazel M.; Kaufmann, Stefan H. E.

2013-01-01

Background Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. Methods We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. Results There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST- and TST+ contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST+ contacts (LTBI) compared to TB and TST- contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. Conclusions Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may

Meta-analyses of the sensitivity and specificity of ante-mortem and post-mortem diagnostic tests for bovine tuberculosis in the UK and Ireland.

PubMed

Nuñez-Garcia, Javier; Downs, Sara H; Parry, Jessica E; Abernethy, Darrell A; Broughan, Jennifer M; Cameron, Angus R; Cook, Alasdair J; de la Rua-Domenech, Ricardo; Goodchild, Anthony V; Gunn, Jane; More, Simon J; Rhodes, Shelley; Rolfe, Simon; Sharp, Michael; Upton, Paul A; Vordermeier, H Martin; Watson, Eamon; Welsh, Michael; Whelan, Adam O; Woolliams, John A; Clifton-Hadley, Richard S; Greiner, Matthias

2018-05-01

Bovine Tuberculosis (bTB) in cattle is a global health problem and eradication of the disease requires accurate estimates of diagnostic test performance to optimize their efficiency. The objective of this study was, through statistical meta-analyses, to obtain estimates of sensitivity (Se) and specificity (Sp), for 14 different ante-mortem and post-mortem diagnostic tests for bTB in cattle. Using data from a systematic review of the scientific literature (published 1934-2009) diagnostic Se and Sp were estimated using Bayesian logistic regression models adjusting for confounding factors. Random effect terms were used to account for unexplained heterogeneity. Parameters in the models were implemented using Markov Chain Monte Carlo (MCMC), and posterior distributions for the diagnostic parameters with adjustment for covariates (confounding factors) were obtained using the inverse logit function. Estimates for Se and/or Sp of the tuberculin skin tests and the IFN-γ blood test were compared with estimates published 2010-2015. Median Se for the single intradermal comparative cervical tuberculin skin (SICCT) test (standard interpretation) was 0.50 and Bayesian credible intervals (CrI) were wide (95% CrI 0.26, 0.78). Median Sp for the SICCT test was 1.00 (95% CrI 0.99, 1.00). Estimates for the IFN-γ blood test Bovine Purified Protein Derivative (PPD)-Avian PPD and Early Secreted Antigen target 6 and Culture Filtrate Protein 10 (ESAT-6/CFP10) ESAT6/CFP10 were 0.67 (95% CrI 0.49, 0.82) and 0.78 (95% CrI 0.60, 0.90) respectively for Se, and 0.98 (95% CrI 0.96, 0.99) and 0.99 (95% CrI 0.99, 1.00) for Sp. The study provides an overview of the accuracy of a range of contemporary diagnostic tests for bTB in cattle. Better understanding of diagnostic test performance is essential for the design of effective control strategies and their evaluation. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Oral delivery of BCG Moreau Rio de Janeiro gives equivalent protection against tuberculosis but with reduced pathology compared to parenteral BCG Danish vaccination.

PubMed

Clark, Simon O; Kelly, Dominic L F; Badell, Edgar; Castello-Branco, Luiz Roberto; Aldwell, Frank; Winter, Nathalie; Lewis, David J M; Marsh, Philip D

2010-10-08

There is a need for an improved vaccine to better control human tuberculosis (TB), as the only currently available TB vaccine, bacillus Calmette-Guerin (BCG) delivered parenterally, offers variable levels of efficacy. Therefore, recombinant strains expressing additional antigens are being developed alongside alternative routes to parenteral delivery. There is strong evidence that BCG Moreau (RdJ) is a safe and effective vaccine in humans when given by the oral route. This study compared the efficacy of a single oral dose of wild type BCG Moreau Rio de Janeiro (RdJ), or a recombinant RdJ strain expressing Ag85B-ESAT6 fusion protein, formulated with and without lipid to enhance oral delivery, with subcutaneous BCG Danish 1331 and saline control groups in a guinea pig aerosol infection model of pulmonary tuberculosis. Protection was measured as survival at 30 weeks post-challenge and reduced bacterial load and histopathology in lungs and spleen. Results showed that a single oral dose of BCG Moreau (RdJ) or recombinant BCG Moreau (RdJ)-Ag85B-ESAT6, formulated with or without lipid, gave protection equivalent to subcutaneously delivered BCG Danish in the 30 weeks post-challenge survival study. The orally delivered vaccines gave reduced pathology scores in the lungs (three of the four formulations) and spleens (all four formulations) compared to subcutaneously delivered BCG Danish. The oral wild type BCG Moreau (RdJ) in lipid and the unformulated oral wild type BCG Moreau (RdJ) vaccine also gave statistically lower bacterial loads in the lungs and spleens, respectively, compared to subcutaneously delivered BCG Danish. This study provides further evidence to show that lipid formulation does not impair vaccine efficacy and may enhance the delivery and stability of oral vaccines intended for use in countries with poor health infrastructure. Oral delivery also avoids needles (and associated cross-infection risks) and immunisation without the need for specially trained

Cross reactive immune responses in cattle arising from exposure to Mycobacterium bovis and non-tuberculous mycobacteria.

PubMed

Jenkins, A O; Gormley, E; Gcebe, N; Fosgate, G T; Conan, A; Aagaard, C; Michel, A L; Rutten, V P M G

2018-04-01

Accurate diagnosis of tuberculosis in cattle may be compromised in areas where there are high rates of exposure to environmental/non-tuberculous mycobacteria (NTM). This cross reaction of immune responses to Mycobacterium bovis antigens shared with NTMs can result in reduced specificity of commonly used diagnostic tests including tuberculin skin tests and the interferon gamma assay (IFN-ɣ). In this study we assessed the cross-reactive immune responses of M. bovis (infected) and NTM exposed animals to M. bovis and M. avium tuberculin, the ESAT6/CFP10 cocktail antigen, tuberculin derived from cultures of selected NTMs, and a panel of recombinant mycobacterium tuberculosis complex (MTBC) antigens sharing homology with orthologues in NTM. Gamma interferon (IFN-ɣ) responses were measured in whole blood cultures using the IFN-ɣ assay and the IFN-ɣ elispot assay on purified peripheral blood mononuclear cells (PBMC). We observed the expected strong IFN-ɣ response to PPD-B in the M. bovis infected animals that distinguished this group from non-infected NTM exposed cattle. The IFN-ɣ responses to PPD-N (M. nonchromogenicum), were relatively high in both infected and non-infected NTM exposed cattle, but were not significantly different to classify the true infection status of each group. The results indicated that the cross-reactive responses to PPD-B and/or PPD-A with PPD-N, likely arose from prior exposure to environmental non-tuberculous mycobacteria. The IFN-ɣ immune responses to the 10 R-Mag measured by the IFN-ɣ elispot assay revealed that three of the selected antigens, Rv3615 (ESpC), Rv0287 (esxG) and the ESAT6/CFP10, were immunogenic in the infected cattle, and distinguished the infected cattle from the non-infected NTM exposed animals. The combined data of PPDs and R-Mags derived from NTM mycobacteria may prove useful in future development of novel bTB diagnostic tests. Copyright © 2018 Elsevier B.V. All rights reserved.

Conservation in gene encoding Mycobacterium tuberculosis antigen Rv2660 and a high predicted population coverage of H56 multistage vaccine in South Africa.

PubMed

Perez-Martinez, Angy P; Ong, Edison; Zhang, Lixin; Marrs, Carl F; He, Yongqun; Yang, Zhenhua

2017-11-01

H56/AERAS-456+IC31 (H56), composed of two early secretion proteins, Ag85B and ESAT-6, and a latency associated protein, Rv2660, and the IC31 Intercell adjuvant, is a new fusion subunit vaccine candidate designed to induce immunity against both new infection and reactivation of latent tuberculosis infection. Efficacy of subunit vaccines may be affected by the diversity of vaccine antigens among clinical strains and the extent of recognition by the diverse HLA molecules in the recipient population. Although a previous study showed the conservative nature of Ag85B- and ESAT-6-encoding genes, genetic diversity of Rv2660c that encodes RV2660 is largely unknown. The population coverage of H56 as a whole yet remains to be assessed. The present study was conducted to address these important knowledge gaps. DNA sequence analysis of Rv2660c found no variation among 83 of the 84 investigated clinical strains belonging to four genetic lineages. H56 was predicted to have as high as 99.6% population coverage in the South Africa population using the Immune Epitope Database (IEDB) Population Coverage Tool. Further comparison of H56 population coverage between South African Blacks and Caucasians based on the phenotypic frequencies of binding MHC Class I and Class II supertype alleles found that all of the nine MHC-I and six of eight MHC-II human leukocyte antigen (HLA) supertype alleles analyzed were significantly differentially expressed between the two subpopulations. This finding suggests the presence of race-specific functional binding motifs of MHC-I and MHC-II HLA alleles, which, in turn, highlights the importance of including diverse populations in vaccine clinical evaluation. In conclusion, H56 vaccine is predicted to have a promising population coverage in South Africa; this study demonstrates the utility of integrating comparative genomics and bioinformatics in bridging animal and clinical studies of novel TB vaccines. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of host responses to Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa.

PubMed

Sutherland, Jayne S; Lalor, Maeve K; Black, Gillian F; Ambrose, Lyn R; Loxton, Andre G; Chegou, Novel N; Kassa, Desta; Mihret, Adane; Howe, Rawleigh; Mayanja-Kizza, Harriet; Gomez, Marie P; Donkor, Simon; Franken, Kees; Hanekom, Willem; Klein, Michel R; Parida, Shreemanta K; Boom, W Henry; Thiel, Bonnie A; Crampin, Amelia C; Ota, Martin; Walzl, Gerhard; Ottenhoff, Tom H M; Dockrell, Hazel M; Kaufmann, Stefan H E

2013-01-01

Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST(-) and TST(+) contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST(+) contacts (LTBI) compared to TB and TST(-) contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy

Identification of gene-specific polymorphisms and association with capsaicin pathway metabolites in Capsicum annuum L. collections.

PubMed

Reddy, Umesh K; Almeida, Aldo; Abburi, Venkata L; Alaparthi, Suresh Babu; Unselt, Desiree; Hankins, Gerald; Park, Minkyu; Choi, Doil; Nimmakayala, Padma

2014-01-01

Pepper (Capsicum annuum L.) is an economically important crop with added nutritional value. Production of capsaicin is an important quantitative trait with high environmental variance, so the development of markers regulating capsaicinoid accumulation is important for pepper breeding programs. In this study, we performed association mapping at the gene level to identify single nucleotide polymorphisms (SNPs) associated with capsaicin pathway metabolites in a diverse Capsicum annuum collection during two seasons. The genes Pun1, CCR, KAS and HCT were sequenced and matched with the whole-genome sequence draft of pepper to identify SNP locations and for further characterization. The identified SNPs for each gene underwent candidate gene association mapping. Association mapping results revealed Pun1 as a key regulator of major metabolites in the capsaicin pathway mainly affecting capsaicinoids and precursors for acyl moieties of capsaicinoids. Six different SNPs in the promoter sequence of Pun1 were found associated with capsaicin in plants from both seasons. Our results support that CCR is an important control point for the flux of p-coumaric acid to specific biosynthesis pathways. KAS was found to regulate the major precursors for acyl moieties of capsaicinoids and may play a key role in capsaicinoid production. Candidate gene association mapping of Pun1 suggested that the accumulation of capsaicinoids depends on the expression of Pun1, as revealed by the most important associated SNPs found in the promoter region of Pun1.

Identification of Gene-Specific Polymorphisms and Association with Capsaicin Pathway Metabolites in Capsicum annuum L. Collections

PubMed Central

Abburi, Venkata L.; Alaparthi, Suresh Babu; Unselt, Desiree; Hankins, Gerald; Park, Minkyu; Choi, Doil

2014-01-01

Pepper (Capsicum annuum L.) is an economically important crop with added nutritional value. Production of capsaicin is an important quantitative trait with high environmental variance, so the development of markers regulating capsaicinoid accumulation is important for pepper breeding programs. In this study, we performed association mapping at the gene level to identify single nucleotide polymorphisms (SNPs) associated with capsaicin pathway metabolites in a diverse Capsicum annuum collection during two seasons. The genes Pun1, CCR, KAS and HCT were sequenced and matched with the whole-genome sequence draft of pepper to identify SNP locations and for further characterization. The identified SNPs for each gene underwent candidate gene association mapping. Association mapping results revealed Pun1 as a key regulator of major metabolites in the capsaicin pathway mainly affecting capsaicinoids and precursors for acyl moieties of capsaicinoids. Six different SNPs in the promoter sequence of Pun1 were found associated with capsaicin in plants from both seasons. Our results support that CCR is an important control point for the flux of p-coumaric acid to specific biosynthesis pathways. KAS was found to regulate the major precursors for acyl moieties of capsaicinoids and may play a key role in capsaicinoid production. Candidate gene association mapping of Pun1 suggested that the accumulation of capsaicinoids depends on the expression of Pun1, as revealed by the most important associated SNPs found in the promoter region of Pun1. PMID:24475113

Comparative study on the pyrolysis behaviour and kinetics of two macroalgae biomass (Gracilaria changii and Gelidium pusillum) by thermogravimetric analysis

NASA Astrophysics Data System (ADS)

Roslee, A. N.; Munajat, N. F.

2017-10-01

Macroalgae are often referred as seaweed and could be significant biomass resource for the production of numerous energy carriers including biofuels. In this study, the chemical composition of Gracilaria changii (G. changii) and Gelidium pusillum (G. pusillum) were determined through proximate and ultimate analysis and the thermal degradation behaviour of G. changii and G. pusillum were investigated via thermogravimetric analysis (TGA) in determining the important main composition to be considered as biomass fuels. It has found the pyrolysis of G. changii and G. pusillum consists of three stages and stage II is the main decomposition stage with major mass loss of around 52.16% and 44.42%, respectively. The TGA data were then used for determination of kinetic parameters of the pyrolysis process using three model-free methods: Kissinger, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The apparent activation energy calculated by using Kissinger method for G. changii was lower than G. Pusillum, i.e.173.12 kJ/mol and 193.22 kJ/mol, respectively. The activation energies calculated from KAS and FWO methods were increased with increasing the pyrolysis conversion with average activation energies of 172.32 kJ/mol and 181.19 kJ/mol for G. changii while for G. pusillum (177.42 kJ/mol and 187.4 kJ/mol). G. pusillum has lower and wider distribution of activation energy and revealed that the pyrolysis process for G. changii was easier than G. pusillum. These data provide information for further application for designing and modelling in thermochemical conversion system of macroalgae biomass.

Intense XUV Radiation Sources.

DTIC Science & Technology

1987-09-30

meetings form Appendices F and H. Earlier work demonstrated the usefulness of laser generated pl -a- as intense light sources in the extreme ultraviolet...in ttile 30- 12 (tlasecr \\kas operated at 101 Hz. Far comiiparisoni ab1outI halt ini reg-ioti. tilie nuttiter oh Shots \\ serc needed to ohii iiIar I...lie pl asmhas were prod uiced h foCUSi11 titlie ou tpu t e xpu SLiFres wu thI a B R\\ sparlk sOITt re hut, at Ilie Puls front a \\d : )A6i laser (1.1004

A Nonsense Mutation in Mycobacterium marinum That Is Suppressible by a Novel Mechanism

PubMed Central

Williams, Emily A.; Mba Medie, Felix; Bosserman, Rachel E.; Johnson, Benjamin K.; Reyna, Cristal; Ferrell, Micah J.; Champion, Matthew M.; Abramovitch, Robert B.

2016-01-01

ABSTRACT Mycobacterial pathogens use the ESAT-6 system 1 (Esx-1) exporter to promote virulence. Previously, we used gene disruption and complementation to conclude that the MMAR_0039 gene in Mycobacterium marinum is required to promote Esx-1 export. Here we applied molecular genetics, proteomics, and whole-genome sequencing to demonstrate that the MMAR_0039 gene is not required for Esx-1 secretion or virulence. These findings suggest that we initially observed an indirect mechanism of genetic complementation. We identified a spontaneous nonsense mutation in a known Esx-1-associated gene which causes a loss of Esx-1 activity. We show that the Esx-1 function was restored by nonsense suppression. Moreover, we identified a polar mutation in the ppsC gene which reduced cellular impermeability but did not impact cytotoxicity in macrophages. Our studies reveal insight into Esx-1 export, nonsense suppression, and cell envelope lipid biogenesis. PMID:27789543

PINTA: a web server for network-based gene prioritization from expression data

PubMed Central

Nitsch, Daniela; Tranchevent, Léon-Charles; Gonçalves, Joana P.; Vogt, Josef Korbinian; Madeira, Sara C.; Moreau, Yves

2011-01-01

PINTA (available at http://www.esat.kuleuven.be/pinta/; this web site is free and open to all users and there is no login requirement) is a web resource for the prioritization of candidate genes based on the differential expression of their neighborhood in a genome-wide protein–protein interaction network. Our strategy is meant for biological and medical researchers aiming at identifying novel disease genes using disease specific expression data. PINTA supports both candidate gene prioritization (starting from a user defined set of candidate genes) as well as genome-wide gene prioritization and is available for five species (human, mouse, rat, worm and yeast). As input data, PINTA only requires disease specific expression data, whereas various platforms (e.g. Affymetrix) are supported. As a result, PINTA computes a gene ranking and presents the results as a table that can easily be browsed and downloaded by the user. PMID:21602267

Continuum Electrostatics Approaches to Calculating pKas and Ems in Proteins.

PubMed

Gunner, M R; Baker, N A

2016-01-01

Proteins change their charge state through protonation and redox reactions as well as through binding charged ligands. The free energy of these reactions is dominated by solvation and electrostatic energies and modulated by protein conformational relaxation in response to the ionization state changes. Although computational methods for calculating these interactions can provide very powerful tools for predicting protein charge states, they include several critical approximations of which users should be aware. This chapter discusses the strengths, weaknesses, and approximations of popular computational methods for predicting charge states and understanding the underlying electrostatic interactions. The goal of this chapter is to inform users about applications and potential caveats of these methods as well as outline directions for future theoretical and computational research. © 2016 Elsevier Inc. All rights reserved.

Continuum Electrostatics Approaches to Calculating pKas and Ems in Proteins

PubMed Central

Gunner, MR; Baker, Nathan A.

2017-01-01

Proteins change their charge state through protonation and redox reactions as well as through binding charged ligands. The free energy of these reactions are dominated by solvation and electrostatic energies and modulated by protein conformational relaxation in response to the ionization state changes. Although computational methods for calculating these interactions can provide very powerful tools for predicting protein charge states, they include several critical approximations of which users should be aware. This chapter discusses the strengths, weaknesses, and approximations of popular computational methods for predicting charge states and understanding their underlying electrostatic interactions. The goal of this chapter is to inform users about applications and potential caveats of these methods as well as outline directions for future theoretical and computational research. PMID:27497160

Biofuels in transport sector of Latvia: experience, current status and barriers

NASA Astrophysics Data System (ADS)

Smigins, R.; Shipkovs, P.

2014-02-01

During the last 10 years biofuel production and utilization in the European Union have become more extensive owing to support provided by the relevant EU Directives. Achievement of the main targets defined by Directives was not simple, being confronted with various barriers. Latvia is one of the EU member-countries that have set an ambitious goal as to the production of biofuel and its use in transport. The authors summarize the major achievements of the country in this area and analyze the main barriers to implementation of biofuels in the transport sector, providing an outlook on the current status of the bioenergy and the transport situation in Latvia. Pēdējo 10 gadu laikā biodegvielu ražošana un izmantošana ES ir kļuvusi daudz plašāka, pateicoties spēcīgam Direktīvu atbalstam. Galveno Direktīvu definēto mērķu sasniegšana nebija viegla un saskārās ar dažādiem sarežģījumiem. Latvija ir viena no ES valstīm, kas uzstādīja ambiciozu mērķi biodegvielu ražošanā un tālākā šīs degvielas izmantošanā transportā. Dotais raksts dod ieskatu galvenajos valsts sasniegumos šajā sfērā, kā arī analizē galvenās barjeras, kas traucē biodegvielu ieviešanu transporta sektorā. Tāpat tiek dots ieskats uz valsts esošo situāciju enerģētikā un transportā.

Underlying thermodynamics of pH-dependent allostery.

PubMed

Di Russo, Natali V; Martí, Marcelo A; Roitberg, Adrian E

2014-11-13

Understanding the effects of coupling protein protonation and conformational states is critical to the development of drugs targeting pH sensors and to the rational engineering of pH switches. In this work, we address this issue by performing a comprehensive study of the pH-regulated switch from the closed to the open conformation in nitrophorin 4 (NP4) that determines its pH-dependent activity. Our calculations show that D30 is the only amino acid that has two significantly different pKas in the open and closed conformations, confirming its critical role in regulating pH-dependent behavior. In addition, we describe the free-energy landscape of the conformational change as a function of pH, obtaining accurate estimations of free-energy barriers and equilibrium constants using different methods. The underlying thermodynamic model of the switch workings suggests the possibility of tuning the observed pKa only through the conformational equilibria, keeping the same conformation-specific pKas, as evidenced by the proposed K125L mutant. Moreover, coupling between the protonation and conformational equilibria results in efficient regulation and pH-sensing around physiological pH values only for some combinations of protonation and conformational equilibrium constants, placing constraints on their possible values and leaving a narrow space for protein molecular evolution. The calculations and analysis presented here are of general applicability and provide a guide as to how more complex systems can be studied, offering insight into how pH-regulated allostery works of great value for designing drugs that target pH sensors and for rational engineering of pH switches beyond the common histidine trigger.

Histidine in Continuum Electrostatics Protonation State Calculations

PubMed Central

Couch, Vernon; Stuchebruckhov, Alexei

2014-01-01

A modification to the standard continuum electrostatics approach to calculate protein pKas which allows for the decoupling of histidine tautomers within a two state model is presented. Histidine with four intrinsically coupled protonation states cannot be easily incorporated into a two state formalism because the interaction between the two protonatable sites of the imidazole ring is not purely electrostatic. The presented treatment, based on a single approximation of the interrelation between histidine’s charge states, allows for a natural separation of the two protonatable sites associated with the imidazole ring as well as the inclusion of all protonation states within the calculation. PMID:22072521

Development and Characterization of Novel Bioluminecent Systems

DTIC Science & Technology

2013-07-01

Ppy I108R. The following primers and their respective reverse compliments were used: Y447E, 5´- CT TTA ATT AAA TAC AAA GGA GAG CAG GTG GCC CCC GCT G...3´ [EcoRV] and I108R, 5´- GGA GTT GCA GTG GCG CCC GCG AAC GAC CGT TAT AAT GAA CGT-3´ [KasI] (bold represents the mutated codons, underlined...primers and their respective reverse compliments: Y447C, 5´- G AAG TCT TTA ATA AAA TAC AAA GGA TGT CAG GTG GCC CCC GCT G -3´ [PacI] and I108C, 5´- GGA

Mapping biomedical concepts onto the human genome by mining literature on chromosomal aberrations

PubMed Central

Van Vooren, Steven; Thienpont, Bernard; Menten, Björn; Speleman, Frank; Moor, Bart De; Vermeesch, Joris; Moreau, Yves

2007-01-01

Biomedical literature provides a rich but unstructured source of associations between chromosomal regions and biomedical concepts. By mining MEDLINE abstracts, we annotate the human genome at the level of cytogenetic bands. Our method creates a set of chromosomal aberration maps that associate cytogenetic bands to biomedical concepts from a variety of controlled vocabularies, including disease, dysmorphology, anatomy, development and Gene Ontology branches. The association between a band (e.g. 4p16.3) and a concept (e.g. microcephaly) is assessed by the statistical overrepresentation of this concept in the abstracts relating to this band. Our method is validated using existing genome annotation resources and known chromosomal aberration maps and is further illustrated through a case study on heart disease. Our chromosomal aberration maps provide diagnostics support to clinical geneticists, aid cytogeneticists to interpret and report cytogenetic findings and support researchers interested in human gene function. The method is available as a web application, aBandApart, at http://www.esat.kuleuven.be/abandapart/. PMID:17403693

Greenhouse Gas Emission Reduction Due to Improvement of Biodegradable Waste Management System

NASA Astrophysics Data System (ADS)

Bendere, R.; Teibe, I.; Arina, D.; Lapsa, J.

2014-12-01

ārdāmo atkritumu apsaimniekošanas statistikas datu novērtējums atbilstoši likumdošanas prasībām. Izmantojot matemātisko modelēšanas programmu WAMPS, analizēti trīs dažādi bioloģisko noārdāmo atkritumu apsaimniekošanas scenāriji, kuriem veikts vides ietekmes novērtējums, kas izteikts klimata pārmaiņu potenciālā - tonnas CO2 ekv. Darbā secināts, ka lielākais siltumnīcefektu (SEG) avots atkritumu apsaimniekošanas ir atkritumu poligoni (Bāzes scenārijs), ko galvenokārt ietekmē CH4 rašanās, organiskajiem atkritumiem sadaloties anaerobos apstākļos. Būtisku pozitīvo efektu SEG emisiju samazināšanā dod atkritumu pārstrāde otrreizējās izejvielās un sadedzināšana cementa ražotnē, kas ļauj samazināt dabīgo izejmateriālu un fosilo enerģijas resursu patēriņu. Attīstot pārtikas atkritumu pārstrādi biogāzē, lietderīgi veidot alternatīvās vai izmantot esošās sistēmas, kas nodrošina iegūtās enerģijas un digestāta patēriņu, t.i lauksaimniecība, transports vai komunālie pakalpojumi. Lai no zaļajiem dārza atkritumiem iegūtu augstvērtīgu kompostu, valstī jārada tam nepieciešami likumdošanas un ekonomiskie instrumenti, kas veicina komposta tirgus attīstību.

Advances in time-scale algorithms

NASA Technical Reports Server (NTRS)

Stein, S. R.

1993-01-01

The term clock is usually used to refer to a device that counts a nearly periodic signal. A group of clocks, called an ensemble, is often used for time keeping in mission critical applications that cannot tolerate loss of time due to the failure of a single clock. The time generated by the ensemble of clocks is called a time scale. The question arises how to combine the times of the individual clocks to form the time scale. One might naively be tempted to suggest the expedient of averaging the times of the individual clocks, but a simple thought experiment demonstrates the inadequacy of this approach. Suppose a time scale is composed of two noiseless clocks having equal and opposite frequencies. The mean time scale has zero frequency. However if either clock fails, the time-scale frequency immediately changes to the frequency of the remaining clock. This performance is generally unacceptable and simple mean time scales are not used. First, previous time-scale developments are reviewed and then some new methods that result in enhanced performance are presented. The historical perspective is based upon several time scales: the AT1 and TA time scales of the National Institute of Standards and Technology (NIST), the A.1(MEAN) time scale of the US Naval observatory (USNO), the TAI time scale of the Bureau International des Poids et Measures (BIPM), and the KAS-1 time scale of the Naval Research laboratory (NRL). The new method was incorporated in the KAS-2 time scale recently developed by Timing Solutions Corporation. The goal is to present time-scale concepts in a nonmathematical form with as few equations as possible. Many other papers and texts discuss the details of the optimal estimation techniques that may be used to implement these concepts.

A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water

PubMed Central

Wu, Xiongwu; Brooks, Bernard R.

2015-01-01

Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66’s pKa. PMID:26506245

A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water.

PubMed

Wu, Xiongwu; Brooks, Bernard R

2015-10-01

Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66's pKa.

Kinetics of the iodine- and bromine-mediated transport of halide ions: demonstration of an interfacial complexation mechanism.

PubMed Central

Klotz, K H; Benz, R

1993-01-01

Stationary and kinetic experiments were performed on lipid bilayer membranes to study the mechanism of iodine- and bromine-mediated halide transport in detail. The stationary conductance data suggested that four different 1:1 complexes between I2 and Br2 and the halides I- and Br- were responsible for the observed conductance increase by iodine and bromine (I3-, I2Br-, Br2I-, and Br3-). Charge pulse experiments allowed the further elucidation of the transport mechanism. Only two of three exponential voltage relaxations predicted by the Läuger model could be resolved under all experimental conditions. This means that either the heterogeneous complexation reactions kR (association) and kD (dissociation) were too fast to be resolved or that the neutral carriers were always in equilibrium within the membrane. Experiments at different carrier and halide concentrations suggested that the translocation of the neutral carrier is much faster than the other processes involved in carrier-mediated ion transport. The model was modified accordingly. From the charge pulse data at different halide concentrations, the translocation rate constant of the complexed carriers, kAS, the dissociation constant, kD, and the total surface concentration of charged carriers, NAS, could be evaluated from one single charge pulse experiment. The association rate of the complex, kR, could be obtained in some cases from the plot of the stationary conductance data as a function of the halide concentration in the aqueous phase. The translocation rate constant, kAS, of the different complexes is a function of the image force and of the Born charging energy. It increases 5000-fold from Br3- to I3- because of an enlarged ion radius. PMID:8312500

Reduction in photosynthetic efficiency of Cladophora glomerata, induced by overlying canopies of Lemna spp.

PubMed

Parr, L B; Perkins, R G; Mason, C F

2002-04-01

The duckweeds Lemna minor L. and L. minuscula Herter reduced PSII quantum efficiency (F'q/F'm) of the filamentous green alga Cladophora glomerata Kützing by up to 42% over seven days when floating above mats of C. glomerata in containers. Dissolved oxygen (DO) increased by 23% at 30 degrees C in containers with C. glomerata over controls. But when the water surface in the containers was covered with Lemna spp. floating above C. glomerata, DO was 83% lower at 30 degrees C over seven days than in control samples with no duckweed or alga. Dissolved oxygen was lower beneath a thick mat (1 cm) of either Lemna spp. covering the surface than under a thin layer (single-frond canopy). PAM fluorimetry showed that maximum PSII efficiency (Fv/Fm) of C. glomerata in containers was reduced under a canopy of L. minor by 17% over seven days, and under L. minuscula by 22%. F'q/F'm of C. glomerata in containers exposed to 51 micromol m(-2) s(-1) PPFD decreased under a canopy of L. minor by 16% over seven days, and under L. minuscula by 19% compared to controls. When light response curves were compared, F'q/F'm was significantly reduced under canopies of L. minor at the highest temperatures tested (28 degrees C and 30 degrees C). L. minor significantly reduced relative electron transport rate (rel. ETR) of the controls by up to 71% at 30 degrees C. Relative electron transport rate did not reach light saturation point (Esat) except at 28 degrees and 30 degrees C under mats of L. minor. Whereas the highest rate of production (rel. ETRmax) and Esat increased with temperature in controls, under a canopy of Lemna, decreases were observed. It is suggested that, during periods of high summer temperature and irradiance, shading inhibits oxygenic photosynthesis in mats of C. glomerata beneath canopies of Lenma spp. This results in less oxygen being produced by the C. glomerata (oxygen produced by Lemna spp. is not released into the water), and this may further inhibit the C. glomerata by

Digital Base Band Converter As Radar Vlbi Backend / Dbbc Kā Ciparošanas Sistēma Radara Vlbi Novērojumiem

NASA Astrophysics Data System (ADS)

Tuccari, G.; Bezrukovs, Vl.; Nechaeva, M.

2012-12-01

can then allow exploring easily the desired range of search for unknown or not fully determined orbit objects. These features make Radar VLBI personality most useful in the space debris measurements. DBBC sistēma izstrādāta Noto Radioastronomijas institūtā. Sistēmas galvenaisuzdevums - palielināt visa Eiropas VLBI tīkla jutību - realizēts, palielinotvisas novērojamās joslas platumu un pielietojot ciparu signālu apstrādes metodes.Izejas datu plūsma palielināta no 1 līdz 4 Gbps katram radioteleskopam un visasoperācijas, kas saistītas ar signālu apstrādi (frekvences pārveidošana, pastiprinājums,iekšējie ģeneratori, utt.), realizētas digitālā formā, kas ļauj iegūt nozīmīgusuzlabojumus atkārtojamībā, precizitātē, vienkāršībā, nemaz neminot vispārzināmāspriekšrocības, ko nodrošina digitālo tehnoloģiju izmantošana. Maksimālā ieejassignāla frekvenču josla ir 3.5 GHz, un momentānais joslas platums ir līdz 1 GHz uzkatru no astoņiem iespējamajiem RF/IF kanāliem. Šī datu reģistrācijas sistēma irļoti veiktspējīga platforma ne tikai EVN, bet arī citiem radioastronomijas pielietojumiem,un papildus tiek izstrādāta vesela virkne programmatūras pakotņu, kasvēl vairāk paplašina sistēmas funkcionalitāti. Tas ietver PFB (Polifāzes FiltruBanka) uztvērējus "Spectra”, kas piemēroti augstas izšķirtspējas spektroskopijasvajadzībām. Papildus realizēts jaunas programmatūras risinājums, ar mērķiizmantot DBBC sistēmu kā daudzfunkcionālu datu ciparošanas iekārtu, kasizmantojama bistatiskiem radara novērojumiem, tai skaitā arī radara VLBInovērojumiem. Šāda veida novērojumos tiek pētīta kosmisko atlūzu populācija,nodrošinot iespēju detektēt pat centimetra

Ni-Al Protective Coating of Steel Electrodes in Dc Electrolysis for Hydrogen Production / Ni-Al Pārklājuma Ietekme Uz Tērauda Elektrodiem Līdzstrāvas Elektrolīzē Ūdeņraža Ražošanai

NASA Astrophysics Data System (ADS)

Aizpurietis, P.; Vanags, M.; Kleperis, J.; Bajars, G.

2013-04-01

Hydrogen can be a good alternative to fossil fuels under the conditions of world's crisis as an effective energy carrier derived from renewable resources. Among all the known methods of hydrogen production, water electrolysis gives the ecologically purest hydrogen, so it is of importance to maximize the efficiency of this process. The authors consider the influence of plasma sprayed Ni-Al protective coating of 316L steel anode-cathode electrodes in DC electrolysis. In a long-term (24 h) process the anode corrodes strongly, losing Cr and Ni ions which are transferred to the electrolyte, while only minor corrosion of the cathode occurs. At the same time, the composition of anode and cathode electrodes protected by Ni-Al coating changes only slightly during a prolonged electrolysis. As the voltammetry and Tafel plots evidence, the Ni-Al coating protects both the anode and cathode from the corrosion and reduces the potential of hydrogen evolution. The results obtained show that such a coating works best in the case of steel electrodes. Darbā pētīts, kā līdzstrāvas elektrolīzē tērauda 316L elektrodus (anods un katods) ietekmē ar plazmas izputināšanas metodi iegūts Ni-Al pārklājums. Tikko uznestam pārklājumam ir mikrostrukturēta virsma, kas kodināšanas laikā mainās, gan pēc reljefa, gan elementu sastāva. Veicot ilgstošu (24 stundas elektrolīzi), atrasts, ka tikai tērauda elektrods anoda lomā intensīvi korodē un zaudē hroma un niķeļa jonus, kas pāriet elektrolītā, turpretī katods mainās relatīvi maz. Pārklājums Ni-Al pēc uznešanas tiek kodināts karstā sārmā, kad tiek izšķīdināta daļa sastāvā esošo elementu (Al, Si, Cd), bet ilgstošas elektrolīzes laikā pārklājuma sastāvs mainās maz gan anodam, gan katodam. Elektrodu elektroķīmiskie raksturlielumi noteikti ar voltamperometrijas un Tāfeļa līkņu analīzes metodēm. Atrasts, ka Ni-Al pārklājums aizsargā gan anodu, gan katodu no korozijas un samazina �

Fused Deposition Modelling as Rapid Prototyping for Structural Material Improvement: Analytical Solution / Ātrās Prototipēšanas Ar Kausēšanas Metodi Strukturālā Uzlabojuma Analītisks Risinājums

NASA Astrophysics Data System (ADS)

Brensons, I.; Polukoshko, S.

2013-10-01

Fused deposition modelling (FDM) is one of the most effective rapid prototyping (RP) techniques due to its low cost, available materials and versatility. In FDM, a part of material (usually plastic) is made by heating this material to the molten state, and from the melt it is extruded through a nozzle and deposited on a surface. In the article, an alternative RP method is considered for improvement of the mechanical properties of a rapid prototype. The authors propose an analytical solution which allows for achievement of this purpose via advanced technologies. The base materials applied in RP technology can be combined with liquid resin which solidifies after a definite time. This makes it possible to create a channel through the prototype and fill it with another material having better mechanical properties. The optimal channel sizes can be chosen in order to raise the strength of material parts. Darbā tiek apskatīts ātrās prototipēšanas veids, kura pamatā ir detaļas veidošana, izmantojot kausētu materiālu parasti plastmasu. Šī detaļu veidošanas metode ir kļuvusi par vienu no visizplatītākajām tās zemo izmaksu, pieejamo materiālu un daudzpusības dēļ. Šī raksta mērķis ir izpētīt alternatīvu veidu, kā uzlabot prototipu mehāniskās īpašības, tādējādi palielinot printētu detaļu izmantošanu kā gala produktu. Raksts piedāvā analītisku risinājumu, kā uzlabot ātro prototipu mehāniskās īpašības, uzlabojot tehnoloģiskos procesus, kas iesaistīti detaļu izgatavošanā. Darba pamatā tiek izmantota 3D printēšanas tehnoloģijas iespēja veidot iekšējus kanālus bez ģeometriskiem ierobežojumiem, kā rezultātā ir iespējams izveidot iekšēju kanālu shēmu, ko pēc tam piepilda ar citu materiālu, kam ir labākas mehāniskās īpašības kā pamata materiālam. Pildīšanai izmantotais materiāls ir epoksīda sveķi, kas pieļauj vieglu iepildīšanu šķidrā fāzē, un sniedz labas mehāniskās īpašības p

Subunit vaccine H56/CAF01 induces a population of circulating CD4 T cells that traffic into the Mycobacterium tuberculosis-infected lung.

PubMed

Woodworth, J S; Cohen, S B; Moguche, A O; Plumlee, C R; Agger, E M; Urdahl, K B; Andersen, P

2017-03-01

The capacity of CD4 T cells to protect against Mycobacterium tuberculosis (Mtb) is governed by their ability to localize to the lung site of infection. Subunit vaccine H56/CAF01, a liposome-adjuvanted fusion protein of Mtb antigens Ag85B, ESAT-6, and Rv2660, conferred durable protection and elicited polyfunctional CD4 T cells that preferentially localized to the lung parenchyma. These lung-resident T cells had reduced KLRG1 and increased CXCR3 expression, an intermediate state of Th1 differentiation that has been associated with Mtb protection. Importantly, KLGR1 - CXCR3 + cells were also enriched in the lung vasculature and peripheral circulation of vaccinated animals, but not controls. Moreover, S1P1R blockade rapidly cleared this population from the blood and adoptive transfer of T cells recovered from the vasculature of vaccinated, but not control, mice efficiently trafficked into the Mtb-infected lung parenchyma. Thus, durable immunity elicited by H56/CAF01 vaccination is associated with the maintenance of circulating CD4 T cells that selectively home to the lung parenchyma.

Optimized data fusion for K-means Laplacian clustering

PubMed Central

Yu, Shi; Liu, Xinhai; Tranchevent, Léon-Charles; Glänzel, Wolfgang; Suykens, Johan A. K.; De Moor, Bart; Moreau, Yves

2011-01-01

Motivation: We propose a novel algorithm to combine multiple kernels and Laplacians for clustering analysis. The new algorithm is formulated on a Rayleigh quotient objective function and is solved as a bi-level alternating minimization procedure. Using the proposed algorithm, the coefficients of kernels and Laplacians can be optimized automatically. Results: Three variants of the algorithm are proposed. The performance is systematically validated on two real-life data fusion applications. The proposed Optimized Kernel Laplacian Clustering (OKLC) algorithms perform significantly better than other methods. Moreover, the coefficients of kernels and Laplacians optimized by OKLC show some correlation with the rank of performance of individual data source. Though in our evaluation the K values are predefined, in practical studies, the optimal cluster number can be consistently estimated from the eigenspectrum of the combined kernel Laplacian matrix. Availability: The MATLAB code of algorithms implemented in this paper is downloadable from http://homes.esat.kuleuven.be/~sistawww/bioi/syu/oklc.html. Contact: shiyu@uchicago.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20980271

NK cells influence both innate and adaptive immune responses after mucosal immunisation with antigen and mucosal adjuvant*

PubMed Central

Hall, Lindsay J; Clare, Simon; Dougan, Gordon

2012-01-01

NK cells were found to be recruited in a temporally controlled manner to the nasal-associated lymphoid tissue and the cervical lymph nodes of mice following intranasal immunisation with Ag85B-ESAT6 antigen from Mycobacterium tuberculosis mixed with Escherichia coli heat-labile toxin as adjuvant. These NK cells were activated and they secreted a diverse range of cytokines and other immunmodulators. Using antibody depletion targeting anti-asialo GM1, we found evidence for altered trafficking, impaired activation and cytokine secretion of dendritic cells, macrophages and neutrophils in immunised NK cell depleted mice compared to control animals. Analysis of antigen-specific immune responses revealed an attenuated antibody and cytokine response in immunised NK cell depleted animals. Systemic administration of rIL-6 but not rIFN-γ significantly restored immune responses in mice depleted of NK cells. In conclusion, cytokine production, particularly IL-6, via NK cells and NK cell activated immune populations, plays an important role in the establishment of local innate immune responses and the consequent development of adaptive immunity after mucosal immunisation. PMID:20220095

Pathogenesis of tuberculosis and other mycobacteriosis.

PubMed

Cardona, Pere-Joan

2018-01-01

The evolution between Mycobacterium tuberculosis infection and active tuberculosis is multifactorial and involves different biological scales. The synthesis of ESAT-6 or the induction of alveolar macrophage necrosis are key, but to understand it, it is necessary to consider the dynamics of endogenous and exogenous reinfection, drainage of lung parenchyma and respiratory mechanics, local fibrosis processes and blood supply. Paradoxically, the immune response generated by the infection is highly protective (90%) against active tuberculosis, although as it is essentially based on the proliferation of Th1 lymphocytes, it cannot prevent reinfection. Severe immunosuppression can only explain 10% of active tuberculosis cases, while the remainder are attributable to comorbidities, a proinflammatory environment and an unknown genetic propensity. The pathogenic capacity of environmental mycobacteria is discrete, linked to deficits in the innate and acquired immune response. The ability to generate biofilms and the ability of M. ulcerans to generate the exotoxin mycolactone is remarkable. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

AIRID: an application of the KAS/Prospector expert system builder to airplane identification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aldridge, J.P.

1984-01-01

The Knowledge Acquisition System/Prospector expert system building tool developed by SRI, International, has been used to construct an expert system to identify aircraft on the basis of observables such as wing shape, engine number/location, fuselage shape, and tail assembly shape. Additional detailed features are allowed to influence the identification as other favorable features. Constraints on the observations imposed by bad weather and distant observations have been included as contexts to the models. Models for Soviet and US fighter aircraft have been included. Inclusion of other types of aircraft such as bombers, transports, and reconnaissance craft is straightforward. Two models permitmore » exploration of the interaction of semantic and taxonomic networks with the models. A full set of text data for fluid communication with the user has been included. The use of demons as triggered output responses to enhance utility to the user has been explored. This paper presents discussion of the ease of building the expert system using this powerful tool and problems encountered in the construction process.« less

Computational prediction of the pKas of small peptides through Conceptual DFT descriptors

NASA Astrophysics Data System (ADS)

Frau, Juan; Hernández-Haro, Noemí; Glossman-Mitnik, Daniel

2017-03-01

The experimental pKa of a group of simple amines have been plotted against several Conceptual DFT descriptors calculated by means of different density functionals, basis sets and solvation schemes. It was found that the best fits are those that relate the pKa of the amines with the global hardness η through the MN12SX density functional in connection with the Def2TZVP basis set and the SMD solvation model, using water as a solvent. The parameterized equation resulting from the linear regression analysis has then been used for the prediction of the pKa of small peptides of interest in the study of diabetes and Alzheimer disease. The accuracy of the results is relatively good, with a MAD of 0.36 units of pKa.

Potential of DosR and Rpf antigens from Mycobacterium tuberculosis to discriminate between latent and active tuberculosis in a tuberculosis endemic population of Medellin Colombia.

PubMed

Arroyo, Leonar; Marín, Diana; Franken, Kees L M C; Ottenhoff, Tom H M; Barrera, Luis F

2018-01-08

Tuberculosis (TB) remains one of the most deadly infectious diseases. One-third to one-fourth of the human population is estimated to be infected with Mycobacterium tuberculosis (Mtb) without showing clinical symptoms, a condition called latent TB infection (LTBI). Diagnosis of Mtb infection is based on the immune response to a mixture of mycobacterial antigens (PPD) or to Mtb specific ESAT-6/CFP10 antigens (IGRA), highly expressed during the initial phase of infection. However, the immune response to PPD and IGRA antigens has a low power to discriminate between LTBI and PTB. The T-cell response to a group of so-called latency (DosR-regulon-encoded) and Resuscitation Promoting (Rpf) antigens of Mtb has been proved to be significantly higher in LTBI compared to active TB across many populations, suggesting their potential use as biomarkers to differentiate latent from active TB. PBMCs from a group LTBI (n = 20) and pulmonary TB patients (PTB, n = 21) from an endemic community for TB of the city of Medellín, Colombia, were in vitro stimulated for 7 days with DosR- (Rv1737c, Rv2029c, and Rv2628), Rpf- (Rv0867c and Rv2389c), the recombinant fusion protein ESAT-6-CFP10 (E6-C10)-, or PPD-antigen. The induced IFNγ levels detectable in the supernatants of the antigen-stimulated cells were then used to calculate specificity and sensitivity in discriminating LTBI from PTB, using different statistical approaches. IFNγ production in response to DosR and Rpf antigens was significantly higher in LTBI compared to PTB. ROC curve analyses of IFNγ production allowed differentiation of LTBI from PTB with areas under the curve higher than 0.70. Furthermore, Multiple Correspondence Analysis (MCA) revealed that LTBI is associated with higher levels of IFNγ in response to the different antigens compared to PTB. Analysis based on decision trees showed that the IFNγ levels produced in response to Rv2029c was the leading variable that best-classified disease status. Finally

The impact of medical tourism on colorectal screening among Korean Americans: A community-based cross-sectional study.

PubMed

Ko, Linda K; Taylor, Victoria M; Yoon, Jihye; Copeland, Wade K; Hwang, Joo Ha; Lee, Eun Jeong; Inadomi, John

2016-12-01

Colorectal cancer (CRC) remains the most commonly diagnosed cancer among Korean Americans (KAs) in part due to low screening rates. Recent studies suggest that some KA patients engage in medical tourism and receive medical care in their home country. The impact of medical tourism on CRC screening is unknown. The purpose of this paper was to 1) investigate the frequency of medical tourism, 2) examine the association between medical tourism and CRC screening, and 3) characterize KA patients who engage in medical tourism. This is a community-based, cross-sectional study involving self-administered questionnaires conducted from August 2013 to October 2013. Data was collected on 193 KA patients, ages 50-75, residing in the Seattle metropolitan area. The outcome variable is up-to-date with CRC screening, defined as having had a stool test (Fecal Occult Blood Test or Fecal Immunochemical Test) within the past year or a colonoscopy within 10 years. Predictor variables are socio-demographics, health factors, acculturation, knowledge, financial concerns for medical care costs, and medical tourism. In multi-variate modeling, medical tourism was significantly related to being up-to-date with CRC screening. Participants who engaged in medical tourism had 8.91 (95% CI: 3.89-23.89) greater odds of being up-to-date with CRC screening compared to those who did not travel for healthcare. Factors associated with engaging in medical tourism were lack of insurance coverage (P = 0.008), higher levels of education (P = 0.003), not having a usual place of care (P = 0.002), older age at immigration (P = 0.009), shorter years-of-stay in the US (P = 0.003), and being less likely to speak English well (P = 0.03). This study identifies the impact of medical tourism on CRC screening and characteristics of KA patients who report engaging in medical tourism. Healthcare providers in the US should be aware of the customary nature of medical tourism among KAs and consider

Differential gene expression at different stages of mesocarp development in high- and low-yielding oil palm.

PubMed

Wong, Yick Ching; Teh, Huey Fang; Mebus, Katharina; Ooi, Tony Eng Keong; Kwong, Qi Bin; Koo, Ka Loo; Ong, Chuang Kee; Mayes, Sean; Chew, Fook Tim; Appleton, David R; Kulaveerasingam, Harikrishna

2017-06-21

The oil yield trait of oil palm is expected to involve multiple genes, environmental influences and interactions. Many of the underlying mechanisms that contribute to oil yield are still poorly understood. In this study, we used a microarray approach to study the gene expression profiles of mesocarp tissue at different developmental stages, comparing genetically related high- and low- oil yielding palms to identify genes that contributed to the higher oil-yielding palm and might contribute to the wider genetic improvement of oil palm breeding populations. A total of 3412 (2001 annotated) gene candidates were found to be significantly differentially expressed between high- and low-yielding palms at at least one of the different stages of mesocarp development evaluated. Gene Ontologies (GO) enrichment analysis identified 28 significantly enriched GO terms, including regulation of transcription, fatty acid biosynthesis and metabolic processes. These differentially expressed genes comprise several transcription factors, such as, bHLH, Dof zinc finger proteins and MADS box proteins. Several genes involved in glycolysis, TCA, and fatty acid biosynthesis pathways were also found up-regulated in high-yielding oil palm, among them; pyruvate dehydrogenase E1 component Subunit Beta (PDH), ATP-citrate lyase, β- ketoacyl-ACP synthases I (KAS I), β- ketoacyl-ACP synthases III (KAS III) and ketoacyl-ACP reductase (KAR). Sucrose metabolism-related genes such as Invertase, Sucrose Synthase 2 and Sucrose Phosphatase 2 were found to be down-regulated in high-yielding oil palms, compared to the lower yield palms. Our findings indicate that a higher carbon flux (channeled through down-regulation of the Sucrose Synthase 2 pathway) was being utilized by up-regulated genes involved in glycolysis, TCA and fatty acid biosynthesis leading to enhanced oil production in the high-yielding oil palm. These findings are an important stepping stone to understand the processes that lead to

Geochemical Fate and Transport of Sildenafil and Vardenafil

NASA Astrophysics Data System (ADS)

Richter, L.; Boudinot, G.; Vulava, V. M.; Cory, W. C.

2015-12-01

The geochemical fate of pharmaceuticals and their degradation products is a developing environmental field. The geologic, chemical, and biological fate of these pollutants has become very relevant with the increase in human population and the resulting increase in pollutant concentrations in the environment. In this study, we focus on sildenafil (SDF) and vardenafil (VDF), active compounds in Viagra and Levitra, respectively, two commonly used erectile dysfunction drugs. The main objective is to determine the sorption potential and transport behavior of these two compounds in natural soils. Both SDF and VDF are complex organic molecules with multiple amine functional groups in their structures. Two types of natural acidic soils (pH≈4.5), an organic-rich soil (7.6% OM) and clay-rich soil (5.1% clay) were used in this study to determine which soil components influence sorption behavior of both compounds. Sorption isotherms measured using batch reactors were nearly linear, but sorption was stronger in soil that contained higher clay content. Both compounds have multiple pKas due to the amine functional groups, the relevant pKas of SDF are 5.97 and 7.27, and those of VDF's are 4.72 and 6.21. These values indicate that these compounds likely behave as cations in soil suspensions and hence were strongly sorbed to negatively-charged clay minerals present in both soils. The clay composition in both soils is predominantly kaolinite with smaller amount of montmorillonite, both of which have a predominantly negative surface charge. Transport experiments using glass chromatography columns indicated that both compounds were more strongly retarded in the clay-rich soils. Breakthrough curves from the transport experiments were modeled using convection-dispersion transport equations. The organic matter in the soil seemed to play a less dominant role in the geochemistry in this study, but is likely to transform both compounds into derivative compounds as seen in other studies.

Field Application of Serodiagnostics To Identify Elephants with Tuberculosis prior to Case Confirmation by Culture

PubMed Central

Greenwald, Rena; Esfandiari, Javan; Mikota, Susan; Miller, Michele; Moller, Torsten; Vogelnest, Larry; Gairhe, Kamal P.; Robbe-Austerman, Suelee; Gai, Jackie; Waters, W. Ray

2012-01-01

Three serologic methods for antibody detection in elephant tuberculosis (TB), the multiantigen print immunoassay (MAPIA), ElephantTB STAT-PAK kit, and DPP VetTB test, were evaluated using serial serum samples from 14 captive elephants infected with Mycobacterium tuberculosis in 5 countries. In all cases, serological testing was performed prior to the diagnosis of TB by mycobacterial culture of trunk wash or tissue samples collected at necropsy. All elephants produced antibody responses to M. tuberculosis antigens, with 13/14 recognizing ESAT-6 and/or CFP10 proteins. The findings supported the high serodiagnostic test accuracy in detecting infections months to years before M. tuberculosis could be isolated from elephants. The MAPIA and/or DPP VetTB assay demonstrated the potential for monitoring antimycobacterial therapy and predicting TB relapse in treated elephants when continuously used in the posttreatment period. History of exposure to TB and past treatment information should be taken into consideration for proper interpretation of the antibody test results. Data suggest that the more frequent trunk wash culture testing of seropositive elephants may enhance the efficiency of the TB diagnostic algorithm, leading to earlier treatment with improved outcomes. PMID:22695162

Humanized NOG mice as a model for tuberculosis vaccine-induced immunity: a comparative analysis with the mouse and guinea pig models of tuberculosis.

PubMed

Grover, Ajay; Troy, Amber; Rowe, Jenny; Troudt, JoLynn M; Creissen, Elizabeth; McLean, Jennifer; Banerjee, Prabal; Feuer, Gerold; Izzo, Angelo A

2017-09-01

The humanized mouse model has been developed as a model to identify and characterize human immune responses to human pathogens and has been used to better identify vaccine candidates. In the current studies, the humanized mouse was used to determine the ability of a vaccine to affect the immune response to infection with Mycobacterium tuberculosis. Both human CD4 + and CD8 + T cells responded to infection in humanized mice as a result of infection. In humanized mice vaccinated with either BCG or with CpG-C, a liposome-based formulation containing the M. tuberculosis antigen ESAT-6, both CD4 and CD8 T cells secreted cytokines that are known to be required for induction of protective immunity. In comparison to the C57BL/6 mouse model and Hartley guinea pig model of tuberculosis, data obtained from humanized mice complemented the data observed in the former models and provided further evidence that a vaccine can induce a human T-cell response. Humanized mice provide a crucial pre-clinical platform for evaluating human T-cell immune responses in vaccine development against M. tuberculosis. © 2017 John Wiley & Sons Ltd.

Collaboratively charting the gene-to-phenotype network of human congenital heart defects

PubMed Central

2010-01-01

Background How to efficiently integrate the daily practice of molecular biologists, geneticists, and clinicians with the emerging computational strategies from systems biology is still much of an open question. Description We built on the recent advances in Wiki-based technologies to develop a collaborative knowledge base and gene prioritization portal aimed at mapping genes and genomic regions, and untangling their relations with corresponding human phenotypes, congenital heart defects (CHDs). This portal is not only an evolving community repository of current knowledge on the genetic basis of CHDs, but also a collaborative environment for the study of candidate genes potentially implicated in CHDs - in particular by integrating recent strategies for the statistical prioritization of candidate genes. It thus serves and connects the broad community that is facing CHDs, ranging from the pediatric cardiologist and clinical geneticist to the basic investigator of cardiogenesis. Conclusions This study describes the first specialized portal to collaboratively annotate and analyze gene-phenotype networks. Of broad interest to the biological community, we argue that such portals will play a significant role in systems biology studies of numerous complex biological processes. CHDWiki is accessible at http://www.esat.kuleuven.be/~bioiuser/chdwiki PMID:20193066

Quantitative structure activity relationships from optimised ab initio bond lengths: steroid binding affinity and antibacterial activity of nitrofuran derivatives

NASA Astrophysics Data System (ADS)

Smith, P. J.; Popelier, P. L. A.

2004-02-01

The present day abundance of cheap computing power enables the use of quantum chemical ab initio data in Quantitative Structure-Activity Relationships (QSARs). Optimised bond lengths are a new such class of descriptors, which we have successfully used previously in representing electronic effects in medicinal and ecological QSARs (enzyme inhibitory activity, hydrolysis rate constants and pKas). Here we use AM1 and HF/3-21G* bond lengths in conjunction with Partial Least Squares (PLS) and a Genetic Algorithm (GA) to predict the Corticosteroid-Binding Globulin (CBG) binding activity of the classic steroid data set, and the antibacterial activity of nitrofuran derivatives. The current procedure, which does not require molecular alignment, produces good r2 and q2 values. Moreover, it highlights regions in the common steroid skeleton deemed relevant to the active regions of the steroids and nitrofuran derivatives.

Thermogravimetric analysis of co-combustion between microalgae and textile dyeing sludge.

PubMed

Peng, Xiaowei; Ma, Xiaoqian; Xu, Zhibin

2015-03-01

The synergistic interaction and kinetics of microalgae, textile dyeing sludge and their blends were investigated under combustion condition by thermogravimetric analysis. The textile dyeing sludge was blended with microalgae in the range of 10-90wt.% to investigate their co-combustion behavior. Results showed that the synergistic interaction between microalgae and textile dyeing sludge improved the char catalytic effect and alkali metals melt-induced effect on the decomposition of textile dyeing sludge residue at high temperature of 530-800°C. As the heating rate increasing, the entire combustion process was delayed but the combustion intensity was enhanced. The lowest average activation energy was obtained when the percentage of microalgae was 60%, which was 227.1kJ/mol by OFW and 227.4kJ/mol by KAS, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Triassic arc-derived detritus in the Triassic Karakaya accretionary complex was not derived from either the S Eurasian margin (Istanbul terrane) or the N Gondwana margin (Taurides)

NASA Astrophysics Data System (ADS)

Ustaömer, Timur; Ayda Ustaömer, Petek; Robertson, Alastair H. F.; Gerdes, Axel; Zulauf, Gernold

2014-05-01

We present new U-Pb zircon source age data for Upper Triassic sandstones of the Istanbul Terrane (S Eurasian margin) and also for Triassic sandstones of the Taurides (N Gondwana margin). The main aim is to detect and quantify the contribution of Triassic magmatism as detritus to either of these crustal blocks. This follows the recent discovery of a Triassic magmatic arc source for the Triassic sandstones of the Palaeotethyan Karakaya subduction-accretion complex (Ustaömer et al. 2013; this meeting). Carboniferous (Variscan) zircon grains also form a significant detrital population, plus several more minor populations. Six sandstone samples were studied, two from the İstanbul Terrane (Bakırlıkıran Formation of the Kocaeli Triassic Basin) and four from the Tauride Autochthon (latest Triassic Üzümdere Formation and Mid-Triassic Kasımlar Formations; Beyşehir region). Detrital zircon grains were dated by the laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) U-Pb method at Goethe University, Frankfurt. Our results do not reveal Triassic detritus in the Üzümdere Formation. The U-Pb age of the analysed zircon grains ranges from 267 Ma to 3.2 Ga. A small fraction of Palaeozoic zircons are Permian (267 to 296 Ma), whereas the remainder are Early Palaeozoic. Ordovician grains (4%) form two age clusters, one at ca. 450 Ma and the other at ca. 474 Ma. Cambrian-aged grains dominate the zircon population, while the second largest population is Ediacaran (576 to 642 Ma). Smaller populations occur at 909-997 Ma, 827-839 Ma, 1.8-2.0 Ga and 2.4-2.6 Ga. The sandstones of the Kasımlar Formation have similar zircon age cluster to those of the somewhat younger Üzümdere Formation, ranging from 239 Ma to 2.9 Ga. A few grains gave Anisian ages. Cambrian zircon grains are less pronounced than in the Kasımlar Formation compared to the Üzümdere Formation. The detrital zircon record of Tauride sandstones, therefore, not indicates significant contribution

Res-E Support Policies in the Baltic States: Electricity Price Aspect (Part II)

NASA Astrophysics Data System (ADS)

Bobinaite, V.; Priedite, I.

2015-04-01

Increasing volumes of electricity derived from renewable energy sources (RES-E) affect the electricity market prices and the prices for final electricity consumers in the Baltic States. The results of a multivariate regression analysis show that in 2013 the RES-E contributed to decreasing the electricity market prices in the Baltic States. However, the final electricity consumers pay for the promotion of RES-E through the approved RES-E component which has a tendency to increase. It is estimated that in 2013 the net benefits from the wind electricity promotion were achieved in Lithuania and Latvia while the net cost - in Estonia. This suggests that the economic efficiency of the wind electricity support scheme based on the application of feed-in tariffs was higher than that based on the feed-in premium. Rakstā analizēta elektroenerģijas ražošanas no atjaunojamiem energoresursiem (AER-E) palielināšanas ietekme uz elektroenerģijas tirgus cenu un gala cenu elektroenerģijas lietotājiem Baltijas valstīs. Daudzfaktoru regresijas analīzes rezultāti atklāja, ka AER-E 2013. gadā varētu samazināt elektroenerģijas tirgus cenas Baltijas valstīs. Tomēr jāņem vērā, ka elektroenerģijas lietotāja gala cenā ir iekļauta AER-E atbalsta komponente, kurai ir raksturīgi palielināties. Aprēķināts, ka no vēja elektroenerģijas ražošanas Latvijā un Lietuvā tika iegūta tīrā peļņa, bet Igaunijā tikai nosedza pašizmaksu. Tas liecina, ka vēja elektroenerģijas atbalsta shēmai, kas balstīta uz obligātā iepirkuma atbalsta principu, ir augstāka ekonomiskā efektivitāte, nekā atbalsta shēmai, kas balstīta uz piemaksu par no AER saražoto elektroenerģiju obligātā iepirkuma ietvaros.

A promising approach for treatment of tumor-induced bone diseases: utilizing bisphosphonate derivatives of nucleoside antimetabolites.

PubMed

Reinholz, Monica M; Zinnen, Shawn P; Dueck, Amylou C; Dingli, David; Reinholz, Gregory G; Jonart, Leslie A; Kitzmann, Kathleen A; Bruzek, Amy K; Negron, Vivian; Abdalla, Abdalla K; Arendt, Bonnie K; Croatt, Anthony J; Sanchez-Perez, Luis; Sebesta, David P; Lönnberg, Harri; Yoneda, Toshiyuki; Nath, Karl A; Jelinek, Diane F; Russell, Stephen J; Ingle, James N; Spelsberg, Thomas C; Dixon, Henry B F Hal; Karpeisky, Alexander; Lingle, Wilma L

2010-07-01

Despite palliative treatments, tumor-induced bone disease (TIBD) remains highly debilitating for many cancer patients and progression typically results in death within two years. Therefore, more effective therapies with enhanced anti-resorptive and cytotoxic characteristics are needed. We developed bisphosphonate-chemotherapeutic conjugates designed to bind bone and hydrolyze, releasing both compounds, thereby targeting both osteoclasts and tumor cells. This study examined the effects of our lead compound, MBC-11 (the anhydride formed between arabinocytidine (AraC)-5'-phosphate and etidronate), on bone tumor burden, bone volume, femur bone mineral density (BMD), and overall survival using two distinct mouse models of TIBD, the 4T1/luc breast cancer and the KAS-6/1-MIP1alpha multiple myeloma models. In mice orthotopically inoculated with 4T1/luc mouse mammary cells, MBC-11 (0.04 microg/day; s.c.) reduced the incidence of bone metastases to 40% (4/10), compared to 90% (9/10; p=0.057) and 100% (5/5; p=0.04) of PBS- or similarly-dosed, zoledronate-treated mice, respectively. MBC-11 also significantly decreased bone tumor burden compared to PBS- or zoledronate-treated mice (p=0.021, p=0.017, respectively). MBC-11 and zoledronate (0.04 microg/day) significantly increased bone volume by two- and four-fold, respectively, compared to PBS-treated mice (p=0.005, p<0.001, respectively). In mice systemically injected with human multiple myeloma KAS-6/1-MIP1alpha cells, 0.04 and 4.0 microg/day MBC-11 improved femur BMD by 13% and 16%, respectively, compared to PBS (p=0.025, p=0.017, respectively) at 10 weeks post-tumor cell injection and increased mean survival to 95 days compared to 77 days in mice treated with PBS (p=0.047). Similar doses of zoledronate also improved femur BMD (p< or =0.01 vs PBS) and increased mean survival to 86 days, but this was not significantly different than in PBS-treated mice (p=0.53). These results demonstrate that MBC-11 decreases bone tumor burden

Thermal Stability and Kinetic Study of Fluvoxamine Stability in Binary Samples with Lactose.

PubMed

Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

2017-04-01

Purpose: In the present study the incompatibility of FLM (fluvoxamine) with lactose in solid state mixtures was investigated. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. Methods: Non-Isothermally stressed physical mixtures were used to calculate the solid-state kinetic parameters. Different thermal models such as Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were used for the characterization of the drug-excipient interaction. Results: Overall, the incompatibility of FLM with lactose as a reducing carbohydrate was successfully evaluated and the activation energy of this interaction was calculated. Conclusion: In this research the lactose and FLM Maillard interaction was proved using physicochemical techniques including DSC and FTIR. It was shown that DSC- based kinetic analysis provides fast and versatile kinetic comparison of Arrhenius activation energies for different pharmaceutical samples.

Thermal Stability and Kinetic Study of Fluvoxamine Stability in Binary Samples with Lactose

PubMed Central

Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

2017-01-01

Purpose: In the present study the incompatibility of FLM (fluvoxamine) with lactose in solid state mixtures was investigated. The compatibility was evaluated using different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. Methods: Non-Isothermally stressed physical mixtures were used to calculate the solid–state kinetic parameters. Different thermal models such as Friedman, Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) were used for the characterization of the drug-excipient interaction. Results: Overall, the incompatibility of FLM with lactose as a reducing carbohydrate was successfully evaluated and the activation energy of this interaction was calculated. Conclusion: In this research the lactose and FLM Maillard interaction was proved using physicochemical techniques including DSC and FTIR. It was shown that DSC- based kinetic analysis provides fast and versatile kinetic comparison of Arrhenius activation energies for different pharmaceutical samples. PMID:28507936

Studies of the chemical basis of the origin of protein synthesis Initiation and direction of peptide growth

NASA Technical Reports Server (NTRS)

Mullins, D. W., Jr.; Lacey, J. C., Jr.

1980-01-01

The data presented in this paper show that the ease of nonenzymatic activation of carboxylic acids by ATP at pH 5 varies directly with the pKa of the carboxyl group, and is consistent with the idea that it is the protonated form of the carboxyl group which participates in the activation reaction. Consequently, since most N-blocked amino acids have higher pKas than do their unblocked forms, they are activated more readily, and it has been demonstrated that this principle applies to peptides as well, which are activated more rapidly than single amino acids. It is proposed that this fact may be partly responsible for the origin of two important features still observed in contemporary protein synthesis: (1) initiation in prokaryotes is accomplished with an N-blocked amino acid, and (2) elongation in all living systems occurs at the carboxyl end of the growing peptide.

MCCE analysis of the pKas of introduced buried acids and bases in staphylococcal nuclease.

PubMed

Gunner, M R; Zhu, Xuyu; Klein, Max C

2011-12-01

The pK(a)s of 96 acids and bases introduced into buried sites in the staphylococcal nuclease protein (SNase) were calculated using the multiconformation continuum electrostatics (MCCE) program and the results compared with experimental values. The pK(a)s are obtained by Monte Carlo sampling of coupled side chain protonation and position as a function of pH. The dependence of the results on the protein dielectric constant (ε(prot)) in the continuum electrostatics analysis and on the Lennard-Jones non-electrostatics parameters was evaluated. The pK(a)s of the introduced residues have a clear dependence on ε(prot,) whereas native ionizable residues do not. The native residues have electrostatic interactions with other residues in the protein favoring ionization, which are larger than the desolvation penalty favoring the neutral state. Increasing ε(prot) scales both terms, which for these residues leads to small changes in pK(a). The introduced residues have a larger desolvation penalty and negligible interactions with residues in the protein. For these residues, changing ε(prot) has a large influence on the calculated pK(a). An ε(prot) of 8-10 and a Lennard-Jones scaling of 0.25 is best here. The X-ray crystal structures of the mutated proteins are found to provide somewhat better results than calculations carried out on mutations made in silico. Initial relaxation of the in silico mutations by Gromacs and extensive side chain rotamer sampling within MCCE can significantly improve the match with experiment. Copyright © 2011 Wiley-Liss, Inc.

Mycobacterium marinum infection in fish and man: epidemiology, pathophysiology and management; a review.

PubMed

Hashish, Emad; Merwad, Abdallah; Elgaml, Shimaa; Amer, Ali; Kamal, Huda; Elsadek, Ahmed; Marei, Ayman; Sitohy, Mahmoud

2018-12-01

Mycobacterium marinum is an opportunistic pathogen inducing infection in fresh and marine water fish. This pathogen causes necrotizing granuloma like tuberculosis, morbidity and mortality in fish. The cell wall-associated lipid phthiocerol dimycocerosates, phenolic glycolipids and ESAT-6 secretion system 1 (ESX-1) are the conserved virulence determinant of the organism. Human infections with Mycobacterium marinum hypothetically are classified into four clinical categories (type I-type IV) and have been associated with the exposure of damaged skin to polluted water from fish pools or contacting objects contaminated with infected fish. Fish mycobacteriosis is clinically manifested and characterized in man by purple painless nodules, liable to develop into superficial crusting ulceration with scar formation. Early laboratory diagnosis of M. marinum including histopathology, culture and PCR is essential and critical as the clinical response to antibiotics requires months to be attained. The pathogenicity and virulence determinants of M. marinum need to be thoroughly and comprehensively investigated and understood. In spite of accumulating information on this pathogen, the different relevant data should be compared, connected and globally compiled. This article is reviewing the epidemiology, virulence factors, diagnosis and disease management in fish while casting light on the potential associated public health hazards.

Evaluation of cytokine responses against novel Mtb antigens as diagnostic markers for TB disease.

PubMed

Awoniyi, Dolapo O; Teuchert, Andrea; Sutherland, Jayne S; Mayanja-Kizza, Harriet; Howe, Rawleigh; Mihret, Adane; Loxton, Andre G; Sheehama, Jacob; Kassa, Desta; Crampin, Amelia C; Dockrell, Hazel M; Kidd, Martin; Rosenkrands, Ida; Geluk, Annemieke; Ottenhoff, Tom H M; Corstjens, P L A M; Chegou, Novel N; Walzl, Gerhard

2016-09-01

We investigated the accuracy of host markers detected in Mtb antigen-stimulated whole blood culture supernatant in the diagnosis of TB. Prospectively, blood from 322 individuals with presumed TB disease from six African sites was stimulated with four different Mtb antigens (Rv0081, Rv1284, ESAT-6/CFP-10, and Rv2034) in a 24 h whole blood stimulation assay (WBA). The concentrations of 42 host markers in the supernatants were measured using the Luminex multiplex platform. Diagnostic biosignatures were investigated through the use of multivariate analysis techniques. 17% of the participants were HIV infected, 106 had active TB disease and in 216 TB was excluded. Unstimulated concentrations of CRP, SAA, ferritin and IP-10 had better discriminating ability than markers from stimulated samples. Accuracy of marker combinations by general discriminant analysis (GDA) identified a six analyte model with 77% accuracy for TB cases and 84% for non TB cases, with a better performance in HIV uninfected patients. A biosignature of 6 cytokines obtained after stimulation with four Mtb antigens has moderate potential as a diagnostic tool for pulmonary TB disease individuals and stimulated marker expression had no added value to unstimulated marker performance. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

YTPdb: a wiki database of yeast membrane transporters.

PubMed

Brohée, Sylvain; Barriot, Roland; Moreau, Yves; André, Bruno

2010-10-01

Membrane transporters constitute one of the largest functional categories of proteins in all organisms. In the yeast Saccharomyces cerevisiae, this represents about 300 proteins ( approximately 5% of the proteome). We here present the Yeast Transport Protein database (YTPdb), a user-friendly collaborative resource dedicated to the precise classification and annotation of yeast transporters. YTPdb exploits an evolution of the MediaWiki web engine used for popular collaborative databases like Wikipedia, allowing every registered user to edit the data in a user-friendly manner. Proteins in YTPdb are classified on the basis of functional criteria such as subcellular location or their substrate compounds. These classifications are hierarchical, allowing queries to be performed at various levels, from highly specific (e.g. ammonium as a substrate or the vacuole as a location) to broader (e.g. cation as a substrate or inner membranes as location). Other resources accessible for each transporter via YTPdb include post-translational modifications, K(m) values, a permanently updated bibliography, and a hierarchical classification into families. The YTPdb concept can be extrapolated to other organisms and could even be applied for other functional categories of proteins. YTPdb is accessible at http://homes.esat.kuleuven.be/ytpdb/. Copyright © 2010 Elsevier B.V. All rights reserved.

High Antigen Dose Is Detrimental to Post-Exposure Vaccine Protection against Tuberculosis.

PubMed

Billeskov, Rolf; Lindenstrøm, Thomas; Woodworth, Joshua; Vilaplana, Cristina; Cardona, Pere-Joan; Cassidy, Joseph P; Mortensen, Rasmus; Agger, Else Marie; Andersen, Peter

2017-01-01

Mycobacterium tuberculosis (Mtb), the etiologic agent of tuberculosis (TB), causes 1.8M deaths annually. The current vaccine, BCG, has failed to eradicate TB leaving 25% of the world's population with latent Mtb infection (LTBI), and 5-10% of these people will reactivate and develop active TB. An efficient therapeutic vaccine targeting LTBI could have an enormous impact on global TB incidence, and could be an important aid in fighting multidrug resistance, which is increasing globally. Here we show in a mouse model using the H56 (Ag85B-ESAT-6-Rv2660) TB vaccine candidate that post-exposure, but not preventive, vaccine protection requires low vaccine antigen doses for optimal protection. Loss of protection from high dose post-exposure vaccination was not associated with a loss of overall vaccine response magnitude, but rather with greater differentiation and lower functional avidity of vaccine-specific CD4 T cells. High vaccine antigen dose also led to a decreased ability of vaccine-specific CD4 T cells to home into the Mtb-infected lung parenchyma, a recently discovered important feature of T cell protection in mice. These results underscore the importance of T cell quality rather than magnitude in TB-vaccine protection, and the significant role that antigen dosing plays in vaccine-mediated protection.

Automated Visual Inspection Of Integrated Circuits

NASA Astrophysics Data System (ADS)

Noppen, G.; Oosterlinck, Andre J.

1989-07-01

One of the major application fields of image processing techniques is the 'visual inspection'. For a number of rea-sons, the automated visual inspection of Integrated Circuits (IC's) has drawn a lot of attention. : Their very strict design makes them very suitable for an automated inspection. : There is already a lot of experience in the comparable Printed Circuit Board (PCB) and mask inspection. : The mechanical handling of wafers and dice is already an established technology. : Military and medical IC's should be a 100 % failproof. : IC inspection gives a high and allinost immediate payback. In this paper we wil try to give an outline of the problems involved in IC inspection, and the algorithms and methods used to overcome these problems. We will not go into de-tail, but we will try to give a general understanding. Our attention will go to the following topics. : An overview of the inspection process, with an emphasis on the second visual inspection. : The problems encountered in IC inspection, as opposed to the comparable PCB and mask inspection. : The image acquisition devices that can be used to obtain 'inspectable' images. : A general overview of the algorithms that can be used. : A short description of the algorithms developed at the ESAT-MI2 division of the katholieke Universiteit Leuven.

Thermal analysis and kinetics of coal during oxy-fuel combustion

NASA Astrophysics Data System (ADS)

Kosowska-Golachowska, Monika

2017-08-01

The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

Proton affinity of the histidine-tryptophan cluster motif from the influenza A virus from ab initio molecular dynamics

NASA Astrophysics Data System (ADS)

Bankura, Arindam; Klein, Michael L.; Carnevale, Vincenzo

2013-08-01

Ab initio molecular dynamics calculations have been used to compare and contrast the deprotonation reaction of a histidine residue in aqueous solution with the situation arising in a histidine-tryptophan cluster. The latter is used as a model of the proton storage unit present in the pore of the M2 proton conducting ion channel. We compute potentials of mean force for the dissociation of a proton from the Nδ and Nɛ positions of the imidazole group to estimate the pKas. Anticipating our results, we will see that the estimated pKa for the first protonation event of the M2 channel is in good agreement with experimental estimates. Surprisingly, despite the fact that the histidine is partially desolvated in the M2 channel, the affinity for protons is similar to that of a histidine in aqueous solution. Importantly, the electrostatic environment provided by the indoles is responsible for the stabilization of the charged imidazolium.

Combustion and kinetic parameters estimation of torrefied pine, acacia and Miscanthus giganteus using experimental and modelling techniques.

PubMed

Wilk, Małgorzata; Magdziarz, Aneta; Gajek, Marcin; Zajemska, Monika; Jayaraman, Kandasamy; Gokalp, Iskender

2017-11-01

A novel approach, linking both experiments and modelling, was applied to obtain a better understanding of combustion characteristics of torrefied biomass. Therefore, Pine, Acacia and Miscanthus giganteus have been investigated under 260°C, 1h residence time and argon atmosphere. A higher heating value and carbon content corresponding to a higher fixed carbon, lower volatile matter, moisture content, and ratio O/C were obtained for all torrefied biomass. TGA analysis was used in order to proceed with the kinetics study and Chemkin calculations. The kinetics analysis demonstrated that the torrefaction process led to a decrease in Ea compared to raw biomass. The average Ea of pine using the KAS method changed from 169.42 to 122.88kJ/mol. The changes in gaseous products of combustion were calculated by Chemkin, which corresponded with the TGA results. The general conclusion based on these investigations is that torrefaction improves the physical and chemical properties of biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal pyrolysis characteristics of macroalgae Cladophora glomerata.

PubMed

Gao, Wenhua; Chen, Kefu; Zeng, Jinsong; Xu, Jun; Wang, Bin

2017-11-01

The Cladophora glomerata (C. glomerata) is a kind of widely distributed macroalgae in the freshwater ecosystems. It primarily consists of carbohydrates that can be converted into biofuel by pyrolysis. In this study, thermogravimetric analysis (TGA) was used to investigate the thermal behavior and kinetics of C. glomerata during the pyrolysis process. The results showed that heating rates slightly affect the decomposition properties of C. glomerata; with the heating rates increasing, the maximum peak of weight loss rate shifted to higher temperatures. The activation energies of C. glomerata pyrolysis reaction were 244.25 and 238.07kJ/mol, respectively, as calculated by Friedman and Kissinger-Akahira-Sunose (KAS) methods. The pre-exponential factor and reaction order were determined by Coats-Redfern model, and applied to simulate the pyrolysis process of C. glomerata. The model calculated data and experimental data were consistent. This study could provide theoretical supports for designing C. glomerata conversion processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrolytic and Kinetic Characteristics of the Thermal Decomposition of Perilla frutescens Polysaccharide

PubMed Central

Zhou, Quancheng; Sheng, Guihua

2012-01-01

The thermal decomposition of Perilla frutescens polysaccharide was examined by thermogravimetry, differential thermogravimetry, and differential thermal analysis. The results showed that the mass loss of the substance proceeded in three steps. The first stage can be attributed to the expulsion of the water from ambient temperature to 182°C. The second stage corresponded to devolatilization from 182°C to 439°C. The residue slowly degraded in the third stage. The weight loss in air is faster than that in nitrogen, because the oxygen in air accelerated the pyrolytic reaction speed reaction. The heating rate significantly affected the pyrolysis of the sample. Similar activation energies of the degradation process (210–211 kJ mol−1) were obtained by the FWO, KAS, and Popescu techniques. According to Popescu mechanism functions, the possible kinetic model was estimated to be Avrami–Erofeev 20 g(α) = [−ln(1–α)]4. PMID:23300715

Chromophore Poling in Thin Films of Organic Glasses. 3. Setup for Corona Triode Discharge / Hromoforu Polarizēšana Plānās Organisko Stiklu Kārtiņās 3. Koronas Izlādes Triodes Ierīce

NASA Astrophysics Data System (ADS)

Vilitis, O.; Titavs, E.; Nitiss, E.; Rutkis, M.

2013-02-01

The corona discharge is described focusing on the advantages of corona triode techniques for the direct current (DC) positive poling of optical polymers. The proposed experimental setup allows the corona poling of nonlinear optical (NLO) polymers in the modes of DC constant current (the lowest 1nA) and of the fixed corona-grid voltage, making it possible to carry out the corona-onset poling at elevated temperature (COPET) up to 200 oC. The setup also provides a wide range of the corona discharge voltage (3 kV - 15 kV), variable reciprocal distance of electrodes as well as the possibility to choose from different types of the corona electrode (needle, multi-needle, wire, etc.). By keeping the corona-to-grid voltage constant, a stable corona discharge at electrode is attained. The grid voltage can be varied in the range from 0 to 3kV. The corona poling area on the sample surface is pre-defined by placing ring spacers above it. The setup is completely computerized, allowing both control and monitoring of the corona discharge, which promotes research into the process of charging NLO polymer samples and selection of the optimal poling mode. Using the voltage-current characteristics and the second-harmonic measurements of a poled polymer we also demonstrate the influence of the setup parameters on the efficiency of poling the thin film NLO polymers. Darba ievadā īsumā aprakstīta koronas izlāde, izceļot koronas triodes theniskās metodes lietošanas priekšrocības optisko polimeru polarizēšanā ar pozitīvās koronas līdzstrāvu. Rakstā apskatīta eksperimentāla koronas polēšanas ierīce, kas sniedz iespēju polarizēt nelineāros optiskos (NLO) polimērus pie konstantas strāvas (līdz pat 1 nA) un fiksēta koronas elektroda-tīkliņa sprieguma, ļaujot veikt polēšanu paaugstinātās temperatūrās līdz 200 oC. Ierīcē paredzētas plašas koronas izlādes sprieguma izvēles robežas (3-15 kV), iespējas mainīt elektrodu savstarpējo izvietojumu un izv

Route of delivery to the airway influences the distribution of pulmonary disease but not the outcome of Mycobacterium tuberculosis infection in rhesus macaques.

PubMed

Sibley, Laura; Dennis, Mike; Sarfas, Charlotte; White, Andrew; Clark, Simon; Gleeson, Fergus; McIntyre, Anthony; Rayner, Emma; Pearson, Geoffrey; Williams, Ann; Marsh, Philip; Sharpe, Sally

2016-01-01

Non-human primates (NHP) provide a key component in the preclinical assessment pathway for new TB vaccines. In the established models, Mycobacterium tuberculosis challenge is typically delivered to airways of macaques either by aerosol or bronchoscopic instillation and therefore, an understanding of these delivery routes would facilitate the comparison of data generated from models using different challenge methods. This study compared the clinical effects, antigen-specific IFNγ response profiles and disease burden following delivery of comparable doses of M. tuberculosis to the lungs of rhesus macaques by either aerosol or bronchoscopic instillation. The outcome of infection in terms of clinical effects and overall disease burden was comparable between both routes of challenge. However, the pathology in the lungs differed as disease was localised to the site of inoculation following bronchoscopic instillation while aerosol exposure resulted in lesions being evenly distributed through the lung. Whilst the IFNγ response to PPD was similar, responses to CFP10 and ESAT6 peptide pools measured with an ex vivo ELISPOT differed with regards to responses to the N-terminal regions depending on the route of infection. Both challenge routes therefore provide valid and comparable models for evaluation of new TB vaccines, although subtle differences in host responses may occur. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Gene expression profile and immunological evaluation of unique hypothetical unknown proteins of Mycobacterium leprae by using quantitative real-time PCR.

PubMed

Kim, Hee Jin; Prithiviraj, Kalyani; Groathouse, Nathan; Brennan, Patrick J; Spencer, John S

2013-02-01

The cell-mediated immunity (CMI)-based in vitro gamma interferon release assay (IGRA) of Mycobacterium leprae-specific antigens has potential as a promising diagnostic means to detect those individuals in the early stages of M. leprae infection. Diagnosis of leprosy is a major obstacle toward ultimate disease control and has been compromised in the past by the lack of specific markers. Comparative bioinformatic analysis among mycobacterial genomes identified potential M. leprae-specific proteins called "hypothetical unknowns." Due to massive gene decay and the prevalence of pseudogenes, it is unclear whether any of these proteins are expressed or are immunologically relevant. In this study, we performed cDNA-based quantitative real-time PCR to investigate the expression status of 131 putative open reading frames (ORFs) encoding hypothetical unknowns. Twenty-six of the M. leprae-specific antigen candidates showed significant levels of gene expression compared to that of ESAT-6 (ML0049), which is an important T cell antigen of low abundance in M. leprae. Fifteen of 26 selected antigen candidates were expressed and purified in Escherichia coli. The seroreactivity to these proteins of pooled sera from lepromatous leprosy patients and cavitary tuberculosis patients revealed that 9 of 15 recombinant hypothetical unknowns elicited M. leprae-specific immune responses. These nine proteins may be good diagnostic reagents to improve both the sensitivity and specificity of detection of individuals with asymptomatic leprosy.

PrimaTB STAT-PAK Assay, a Novel, Rapid Lateral-Flow Test for Tuberculosis in Nonhuman Primates▿

PubMed Central

Lyashchenko, Konstantin P.; Greenwald, Rena; Esfandiari, Javan; Greenwald, David; Nacy, Carol A.; Gibson, Susan; Didier, Peter J.; Washington, Marc; Szczerba, Peter; Motzel, Sherri; Handt, Larry; Pollock, John M.; McNair, James; Andersen, Peter; Langermans, Jan A. M.; Verreck, Frank; Ervin, Sean; Ervin, Frank; McCombs, Candace

2007-01-01

Tuberculosis (TB) is the most important zoonotic bacterial disease in nonhuman primates (NHP). The current diagnostic method, the intradermal palpebral tuberculin test, has serious shortcomings. We characterized antibody responses in NHP against Mycobacterium tuberculosis to identify immunodominant antigens and develop a rapid serodiagnostic test for TB. A total of 422 NHP were evaluated, including 243 rhesus (Macaca mulatta), 46 cynomolgus (Macaca fascicularis), and 133 African green (Cercopithecus aethiops sabaeus) monkeys at five collaborative centers. Of those, 50 monkeys of the three species were experimentally inoculated with M. tuberculosis. Antibody responses were monitored every 2 to 4 weeks for up to 8 months postinfection by MultiAntigen Print ImmunoAssay with a panel of 12 recombinant antigens. All of the infected monkeys produced antibodies at various levels and with different antigen recognition patterns. ESAT-6 and MPB83 were the most frequently recognized proteins during infection. A combination of selected antigens which detected antibodies in all of the infected monkeys was designed to develop the PrimaTB STAT-PAK assay by lateral-flow technology. Serological evaluation demonstrated high diagnostic sensitivity (90%) and specificity (99%). The highest rate of TB detection was achieved when the skin test was combined with the PrimaTB STAT-PAK kit. This novel immunoassay provides a simple, rapid, and accurate test for TB in NHP. PMID:17652522

A Promising Listeria-Vectored Vaccine Induces Th1-Type Immune Responses and Confers Protection Against Tuberculosis.

PubMed

Yin, Yuelan; Lian, Kai; Zhao, Dan; Tao, Chengwu; Chen, Xiang; Tan, Weijun; Wang, Xiaobo; Xu, Zhengzhong; Hu, Maozhi; Rao, Yan; Zhou, Xiaohui; Pan, Zhiming; Zhang, Xiaoming; Jiao, Xin'an

2017-01-01

Deaths associated with tuberculosis (TB) is rising and accounted for 1.4 million deaths in 2015 many of which were due to drug-resistant bacteria. Vaccines represent an important medical intervention, but the current Bacilli Calmette-Guerin (BCG) vaccine is not ideal for the protection of teenagers and adults. Therefore, a safe and effective vaccine is urgently needed. In this study, we designed a novel vaccine using an attenuated Listeria monocytogenes strain carrying fusion antigen FbpB-ESAT-6 (rLM) and characterized its safety and protective efficacy against Mycobacterium tuberculosis ( M.tb ) infection in mice. Compared to the wild type strain yzuLM4 and parental strain LMΔ actA/plcB (LM1-2), the virulence of rLM was significantly reduced as judged by its infectious kinetics and LD 50 dose. Further characterization of intravenous immunization showed that prime-boost vaccination significantly increased the levels of Th1 cytokines (IFN-γ, IL-17, and IL-6), and enhanced cytotoxic T lymphocyte (CTL) CTLs activity, suggesting that rLM could elicit potent Th1/Th17 responses. More importantly, rLM significantly conferred the protection against M.tb H37Rv challenge. Collectively, our findings indicated that rLM is a novel and useful tool to prevent M.tb infection, and can be potentially be used to boost BCG-primed immunity.

Field evaluation of the protective efficacy of Mycobacterium bovis BCG vaccine against bovine tuberculosis.

PubMed

Lopez-Valencia, G; Renteria-Evangelista, T; Williams, J de Jesús; Licea-Navarro, A; Mora-Valle, A De la; Medina-Basulto, G

2010-02-01

The protective efficacy of Mycobacterium bovis BCG (1 x 10(6) single dose) was evaluated under field conditions. A total of 140 male Holstein Friesian calves, one to two week-old were selected. Two groups of 70 each were formed, one group was vaccinated and the other was injected with a placebo during their second week of age and followed until 12 months of age. The study considered a positive case of tuberculosis to be an animal that had a positive reaction to the three following tests in a row: tuberculin, IFNgamma PPD-B and IFNgamma ESAT6-CFP10 during the 12 months of exposure. The results showed a 59.4% efficacy (IC95%: 47.64-71.16). The non-vaccinated calves were 2.4 times more at risk of becoming infected (IC95%: 1.07-5.68) compared to vaccinated animals. As a complementary test a PCR test was performed using nasal exudates in some animals from both groups using a Mycobacterium complex detection kit. All the positive PCR reactions (5/44) were found in the non-vaccinated animals. These findings suggest that the use of the BCG vaccine, even though it is not capable of protecting 100%, does prevent TB vaccinated animals from excreting bacilli in their nasal secretions at their first year of age. Copyright 2009 Elsevier Ltd. All rights reserved.

Direct cell-cell contact activates SigM to express the ESX-4 secretion system in Mycobacterium smegmatis.

PubMed

Clark, Ryan R; Judd, Julius; Lasek-Nesselquist, Erica; Montgomery, Sarah A; Hoffmann, Jennifer G; Derbyshire, Keith M; Gray, Todd A

2018-06-25

Conjugal cell-cell contact between strains of Mycobacterium smegmatis induces the esxUT transcript, which encodes the putative primary substrates of the ESAT-6 secretion system 4 (ESX-4) secretion system. This recipient response was required for conjugal transfer of chromosomal DNA from the donor strain. Here we show that the extracytoplasmic σ factor, SigM, is a cell contact-dependent activator of ESX-4 expression and is required for conjugal transfer of DNA in the recipient strain. The SigM regulon includes genes outside the seven-gene core esx4 locus that we show are also required for conjugation, and we show that some of these SigM-induced proteins likely function through ESX-4. A fluorescent reporter revealed that SigM is specifically activated in recipient cells in direct contact with donor cells. Coculture RNA-seq experiments indicated that SigM regulon induction occurred early and before transconjugants are detected. This work supports a model wherein donor contact with the recipient cell surface inactivates the transmembrane anti-SigM, thereby releasing SigM. Free SigM induces an extended ESX-4 secretion system, resulting in changes that facilitate chromosomal transfer. The contact-dependent inactivation of an extracytoplasmic σ-factor that tightly controls ESX-4 activity suggests a mechanism dedicated to detect, and appropriately respond to, external stimuli from mycobacteria.

Structure of a PE-PPE-EspG complex from Mycobacterium tuberculosis reveals molecular specificity of ESX protein secretion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ekiert, Damian C.; Cox, Jeffery S.

Nearly 10% of the coding capacity of the Mycobacterium tuberculosis genome is devoted to two highly expanded and enigmatic protein families called PE and PPE, some of which are important virulence/immunogenicity factors and are secreted during infection via a unique alternative secretory system termed "type VII." How PE-PPE proteins function during infection and how they are translocated to the bacterial surface through the five distinct type VII secretion systems [ESAT-6 secretion system (ESX)] of M. tuberculosis is poorly understood. Here in this paper, we report the crystal structure of a PE-PPE heterodimer bound to ESX secretion-associated protein G (EspG), whichmore » adopts a novel fold. This PE-PPE-EspG complex, along with structures of two additional EspGs, suggests that EspG acts as an adaptor that recognizes specific PE-PPE protein complexes via extensive interactions with PPE domains, and delivers them to ESX machinery for secretion. Surprisingly, secretion of most PE-PPE proteins in M. tuberculosis is likely mediated by EspG from the ESX-5 system, underscoring the importance of ESX-5 in mycobacterial pathogenesis. Furthermore, our results indicate that PE-PPE domains function as cis-acting targeting sequences that are read out by EspGs, revealing the molecular specificity for secretion through distinct ESX pathways.« less

Structure of a PE-PPE-EspG complex from Mycobacterium tuberculosis reveals molecular specificity of ESX protein secretion

DOE PAGES

Ekiert, Damian C.; Cox, Jeffery S.

2014-10-01

Nearly 10% of the coding capacity of the Mycobacterium tuberculosis genome is devoted to two highly expanded and enigmatic protein families called PE and PPE, some of which are important virulence/immunogenicity factors and are secreted during infection via a unique alternative secretory system termed "type VII." How PE-PPE proteins function during infection and how they are translocated to the bacterial surface through the five distinct type VII secretion systems [ESAT-6 secretion system (ESX)] of M. tuberculosis is poorly understood. Here in this paper, we report the crystal structure of a PE-PPE heterodimer bound to ESX secretion-associated protein G (EspG), whichmore » adopts a novel fold. This PE-PPE-EspG complex, along with structures of two additional EspGs, suggests that EspG acts as an adaptor that recognizes specific PE-PPE protein complexes via extensive interactions with PPE domains, and delivers them to ESX machinery for secretion. Surprisingly, secretion of most PE-PPE proteins in M. tuberculosis is likely mediated by EspG from the ESX-5 system, underscoring the importance of ESX-5 in mycobacterial pathogenesis. Furthermore, our results indicate that PE-PPE domains function as cis-acting targeting sequences that are read out by EspGs, revealing the molecular specificity for secretion through distinct ESX pathways.« less

The tuberculin skin test increases the responses measured by T cell interferon-gamma release assays.

PubMed

Vilaplana, C; Ruiz-Manzano, J; Gil, O; Cuchillo, F; Montané, E; Singh, M; Spallek, R; Ausina, V; Cardona, P J

2008-06-01

RUTI is a vaccine consisting of Mycobacterium tuberculosis bacilli grown in stress conditions that is fragmented, detoxified and liposomed. RUTI was designed to shorten the treatment of latent tuberculosis infection (LTBI) with isoniazid from 9 months to just 1 month, by additional treatment with two inoculations of RUTI 4 weeks apart. During the validation process for monitoring the immunogenicity of administration of RUTI in a Phase I clinical trial, the question arose whether to introduce the tuberculin skin test (TST) in the screening of non-LTBI volunteers. This study was designed to evaluate the effect of TST on subsequent different T-cell interferon-gamma release assay (TIGRA) responses, using a spectrum of M. tuberculosis-related antigens (ESAT-6, CFP-10, 16 kDa, 19 kDa, MPT64, Ag 85B, 38 kDa, hsp65, PPD and BCG). The results showed an increase in post-TST response even in non-LTBI subjects for most antigens tested, as measured both by whole blood assay (WBA) and ELISPOT. Increased ELISPOT response decreased toward pre-TST levels within 1 month whereas the WBA response did not. Taking into account that there is no definitive correlation between TST and TIGRA tests to diagnose LTBI and the feasibility that TST might alter the immune monitoring included in clinical trials, these data suggest that TST determination should be carefully planned to avoid any interference with TIGRA.

High Antigen Dose Is Detrimental to Post-Exposure Vaccine Protection against Tuberculosis

PubMed Central

Billeskov, Rolf; Lindenstrøm, Thomas; Woodworth, Joshua; Vilaplana, Cristina; Cardona, Pere-Joan; Cassidy, Joseph P.; Mortensen, Rasmus; Agger, Else Marie; Andersen, Peter

2018-01-01

Mycobacterium tuberculosis (Mtb), the etiologic agent of tuberculosis (TB), causes 1.8M deaths annually. The current vaccine, BCG, has failed to eradicate TB leaving 25% of the world’s population with latent Mtb infection (LTBI), and 5–10% of these people will reactivate and develop active TB. An efficient therapeutic vaccine targeting LTBI could have an enormous impact on global TB incidence, and could be an important aid in fighting multidrug resistance, which is increasing globally. Here we show in a mouse model using the H56 (Ag85B-ESAT-6-Rv2660) TB vaccine candidate that post-exposure, but not preventive, vaccine protection requires low vaccine antigen doses for optimal protection. Loss of protection from high dose post-exposure vaccination was not associated with a loss of overall vaccine response magnitude, but rather with greater differentiation and lower functional avidity of vaccine-specific CD4 T cells. High vaccine antigen dose also led to a decreased ability of vaccine-specific CD4 T cells to home into the Mtb-infected lung parenchyma, a recently discovered important feature of T cell protection in mice. These results underscore the importance of T cell quality rather than magnitude in TB-vaccine protection, and the significant role that antigen dosing plays in vaccine-mediated protection. PMID:29379507

The effect of orthology and coregulation on detecting regulatory motifs.

PubMed

Storms, Valerie; Claeys, Marleen; Sanchez, Aminael; De Moor, Bart; Verstuyf, Annemieke; Marchal, Kathleen

2010-02-03

Computational de novo discovery of transcription factor binding sites is still a challenging problem. The growing number of sequenced genomes allows integrating orthology evidence with coregulation information when searching for motifs. Moreover, the more advanced motif detection algorithms explicitly model the phylogenetic relatedness between the orthologous input sequences and thus should be well adapted towards using orthologous information. In this study, we evaluated the conditions under which complementing coregulation with orthologous information improves motif detection for the class of probabilistic motif detection algorithms with an explicit evolutionary model. We designed datasets (real and synthetic) covering different degrees of coregulation and orthologous information to test how well Phylogibbs and Phylogenetic sampler, as representatives of the motif detection algorithms with evolutionary model performed as compared to MEME, a more classical motif detection algorithm that treats orthologs independently. Under certain conditions detecting motifs in the combined coregulation-orthology space is indeed more efficient than using each space separately, but this is not always the case. Moreover, the difference in success rate between the advanced algorithms and MEME is still marginal. The success rate of motif detection depends on the complex interplay between the added information and the specificities of the applied algorithms. Insights in this relation provide information useful to both developers and users. All benchmark datasets are available at http://homes.esat.kuleuven.be/~kmarchal/Supplementary_Storms_Valerie_PlosONE.

Synthetic control and empirical prediction of redox potentials for Co 4O 4 cubanes over a 1.4 V range: implications for catalyst design and evaluation of high-valent intermediates in water oxidation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Andy I.; Wang, Jianing; Levine, Daniel S.

The oxo-cobalt cubane unit [Co 4O 4] is of interest as a homogeneous oxygen-evolution reaction (OER) catalyst, and as a functional mimic of heterogeneous cobalt oxide OER catalysts. The synthesis of several new cubanes allows evaluation of redox potentials for the [Co 4O 4] cluster, which are highly sensitive to the ligand environment and span a remarkable range of 1.42 V. The [Co III 4O 4] 4+/[Co III 3Co IVO 4 ]5+ and [Co III 3Co IVO 4] 5+/[Co III 2Co IV 2O 4] 6+ redox potentials are reliably predicted by the pKas of the ligands. Hydrogen bonding is alsomore » shown to significantly raise the redox potentials, by ~500 mV. The potential-p K a correlation is used to evaluate the feasibility of various proposed OER catalytic intermediates, including high-valent Co-oxo species. The synthetic methods and structure–reactivity relationships developed by these studies should better guide the design of new cubane-based OER catalysts.« less

Thermal decomposition and kinetics of coal and fermented cornstalk using thermogravimetric analysis.

PubMed

He, Yuyuan; Chang, Chun; Li, Pan; Han, Xiuli; Li, Hongliang; Fang, Shuqi; Chen, Junying; Ma, Xiaojian

2018-07-01

The thermal behavior and kinetics of Yiluo coal (YC) and the residues of fermented cornstalk (FC) were investigated in this study. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used for the kinetic analysis of the pyrolysis process. The results showed that the activation energy (E α ) was increased with the increase of the thermal conversion rate (α), and the average values of E α of YC, FC and the blend (m YC /m FC  = 6/4) were 304.26, 224.94 and 233.46 kJ/mol, respectively. The order reaction model function for the blend was also developed by the master-plots method. By comparing the E a and the enthalpy, it was found that the blend was favored to format activated complex due to the lower potential energy barrier. Meanwhile, the average value of Gibbs free energy of the blend was 169.83 kJ/mol, and the changes of entropies indicated that the pyrolysis process was evolved from ordered-state to disordered-state. Copyright © 2018 Elsevier Ltd. All rights reserved.

Thermogravimetric kinetic modelling of in-situ catalytic pyrolytic conversion of rice husk to bioenergy using rice hull ash catalyst.

PubMed

Loy, Adrian Chun Minh; Gan, Darren Kin Wai; Yusup, Suzana; Chin, Bridgid Lai Fui; Lam, Man Kee; Shahbaz, Muhammad; Unrean, Pornkamol; Acda, Menandro N; Rianawati, Elisabeth

2018-08-01

The thermal degradation behaviour and kinetic parameter of non-catalytic and catalytic pyrolysis of rice husk (RH) using rice hull ash (RHA) as catalyst were investigated using thermogravimetric analysis at four different heating rates of 10, 20, 50 and 100 K/min. Four different iso conversional kinetic models such as Kissinger, Friedman, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) were applied in this study to calculate the activation energy (E A ) and pre-exponential value (A) of the system. The E A of non-catalytic and catalytic pyrolysis was found to be in the range of 152-190 kJ/mol and 146-153 kJ/mol, respectively. The results showed that the catalytic pyrolysis of RH had resulted in a lower E A as compared to non-catalytic pyrolysis of RH and other biomass in literature. Furthermore, the high Gibb's free energy obtained in RH implied that it has the potential to serve as a source of bioenergy production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Progress in the prediction of pKa values in proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexov, Emil; Mehler, Ernest L.; Baker, Nathan A.

2011-12-15

The pKa-cooperative aims to provide a forum for experimental and theoretical researchers interested in protein pKa values and protein electrostatics in general. The first round of the pKa -cooperative, which challenged computational labs to carry out blind predictions against pKas experimentally determined in the laboratory of Bertrand Garcia-Moreno, was completed and results discussed at the Telluride meeting (July 6-10, 2009). This paper serves as an introduction to the reports submitted by the blind prediction participants that will be published in a special issue of PROTEINS: Structure, Function and Bioinformatics. Here we briefly outline existing approaches for pKa calculations, emphasizing methodsmore » that were used by the participants in calculating the blind pKa values in the first round of the cooperative. We then point out some of the difficulties encountered by the participating groups in making their blind predictions, and finally try to provide some insights for future developments aimed at improving the accuracy of pKa calculations.« less

Myeloma Xenograft Destruction by a Nonviral Vector Delivering Oncolytic Infectious Nucleic Acid

PubMed Central

Hadac, Elizabeth M; Kelly, Elizabeth J; Russell, Stephen J

2011-01-01

The feasibility of using a nonviral vector formulation to initiate an oncolytic viral infection has not been previously demonstrated. We therefore sought to determine whether infectious nucleic acid (INA) could be used in place of virus particles to initiate an oncolytic picornavirus infection in vivo. Infectious RNA encoding coxsackievirus A21 (CVA21) was transcribed from plasmid DNA using T7 polymerase. Within 48 hours of injecting this RNA into KAS6/1 myeloma xenografts, high titers of infectious CVA21 virions were detected in the bloodstream. Tumors regressed rapidly thereafter and mice developed signs of myositis. At euthanasia, CVA21 was recovered from regressing tumors and from skeletal muscles. Treatment outcomes were comparable following intratumoral injection of naked RNA or fully infectious CVA21 virus. Dose–response studies showed that an effective oncolytic infection could be established by intratumoral injection of 1 µg of infectious RNA. The oncolytic infection could also be initiated by intravenous injection of infectious RNA. Our study demonstrates that INA is a highly promising alternative drug formulation for oncolytic virotherapy. PMID:21505425

Determination of Kinetic Parameters for the Thermal Decomposition of Parthenium hysterophorus

NASA Astrophysics Data System (ADS)

Dhaundiyal, Alok; Singh, Suraj B.; Hanon, Muammel M.; Rawat, Rekha

2018-02-01

A kinetic study of pyrolysis process of Parthenium hysterophorous is carried out by using thermogravimetric analysis (TGA) equipment. The present study investigates the thermal degradation and determination of the kinetic parameters such as activation E and the frequency factor A using model-free methods given by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger, and model-fitting (Coats Redfern). The results derived from thermal decomposition process demarcate decomposition of Parthenium hysterophorous among the three main stages, such as dehydration, active and passive pyrolysis. It is shown through DTG thermograms that the increase in the heating rate caused temperature peaks at maximum weight loss rate to shift towards higher temperature regime. The results are compared with Coats Redfern (Integral method) and experimental results have shown that values of kinetic parameters obtained from model-free methods are in good agreement. Whereas the results obtained through Coats Redfern model at different heating rates are not promising, however, the diffusion models provided the good fitting with the experimental data.

Development of a Synthetic Oxytetracycline-Inducible Expression System for Streptomycetes Using de Novo Characterized Genetic Parts.

PubMed

Wang, Weishan; Yang, Tongjian; Li, Yihong; Li, Shanshan; Yin, Shouliang; Styles, Kathryn; Corre, Christophe; Yang, Keqian

2016-07-15

Precise control of gene expression using exogenous factors is of great significance. To develop ideal inducible expression systems for streptomycetes, new genetic parts, oxytetracycline responsive repressor OtrR, operator otrO, and promoter otrBp from Streptomyces rimosus, were selected de novo and characterized in vivo and in vitro. OtrR showed strong affinity to otrO (KD = 1.7 × 10(-10) M) and oxytetracycline induced dissociation of the OtrR/DNA complex in a concentration-dependent manner. On the basis of these genetic parts, a synthetic inducible expression system Potr* was optimized. Induction of Potr* with 0.01-4 μM of oxytetracycline triggered a wide-range expression level of gfp reporter gene in different Streptomyces species. Benchmarking Potr* against the widely used constitutive promoters ermE* and kasOp* revealed greatly enhanced levels of expression when Potr* was fully induced. Finally, Potr* was used as a tool to activate and optimize the expression of the silent jadomycin biosynthetic gene cluster in Streptomyces venezuelae. Altogether, the synthetic Potr* presents a new versatile tool for fine-tuning gene expression in streptomycetes.

Discernment of synergism in pyrolysis of biomass blends using thermogravimetric analysis.

PubMed

Mallick, Debarshi; Poddar, Maneesh Kumar; Mahanta, Pinakeswar; Moholkar, Vijayanand S

2018-08-01

This study reports pyrolysis kinetics of biomass blends using isoconversional methods, viz. Friedman, FWO and KAS. Blends of three biomasses, viz. saw dust, bamboo dust and rice husk, were used. Extractives and volatiles in biomass and minerals in ash had marked influence on enhancement of reaction kinetics during co-pyrolysis, as indicated by reduction in activation energy and increase in decomposition intensity. Pyrolysis kinetics of saw dust and rice husk accelerated (positive synergy), while that of bamboo dust decelerated after blending (negative synergy). Predominant reaction mechanism of all biomass blends was 3-D diffusion in lower conversion range (α ≤ 0.5), while for α ≥ 0.5 pyrolysis followed random nucleation (or nucleation and growth mechanism). Higher reaction order for pyrolysis of blends of rice husk with saw dust and bamboo dust was attributed to catalytic effect of minerals in ash. Positive ΔH and ΔG was obtained for pyrolysis of all biomass blends. Copyright © 2018 Elsevier Ltd. All rights reserved.

New class of 19F pH indicators: fluoroanilines.

PubMed Central

Deutsch, C J; Taylor, J S

1989-01-01

The pH dependence of the 19F chemical shift has been characterized for a number of fluorine-substituted aniline derivatives. These compounds constitute a new class of 19F nuclear magnetic resonance (NMR) pH indicators, characterized by single 19F resonance lines with sensitivities ranging from 2 to 7 ppm/pH unit near the aniline pKa; total shifts between conjugate acid and base of 5-15 ppm; and pKas ranging from 1 to 7. One compound, N,N-(methyl-2-carboxyisopropyl)-4-fluoroaniline, has a pKa of 6.8 and a sensitivity of 5 ppm/pH unit. This compound displays significant broadening of its 19F resonance near the aniline pKa (6.8), due to a decreased rate of exchange between conjugate acid and base species. Our results are consistent with slow dissociation of an intramolecular hydrogen bond in the zwitterionic species that limits the exchange rate between protonated and unprotonated forms for N,N-(methyl-2-carboxyisopropyl)-4-fluoroaniline. PMID:2720073

Degradation of anionic surfactants during drying of UASBR sludges on sand drying beds.

PubMed

Mungray, Arvind Kumar; Kumar, Pradeep

2008-09-01

Anionic surfactant (AS) concentrations in wet up-flow anaerobic sludge blanket reactor (UASBR) sludges from five sewage treatment plants (STPs) were found to range from 4480 to 9,233 mg kg(-1)dry wt. (average 7,347 mg kg(-1)dry wt.) over a period of 18 months. After drying on sand drying beds (SDBs), AS in dried-stabilized sludges averaged 1,452 mg kg(-1)dry wt., a reduction of around 80%. The kinetics of drying followed simple first-order reduction of moisture with value of drying constant (k(d))=0.051 d(-1). Reduction of AS also followed first-order kinetics. AS degradation rate constant (k(AS)) was found to be 0.034 d(-1) and half-life of AS as 20 days. The order of rates of removal observed was k(d)>k(AS)>k(COD)>k(OM) (drying >AS degradation>COD reduction>organic matter reduction). For the three applications of dried-stabilized sludges (soil, agricultural soil, grassland), values of risk quotient (RQ) were found to be <1, indicating no risk.

Synthetic control and empirical prediction of redox potentials for Co 4O 4 cubanes over a 1.4 V range: implications for catalyst design and evaluation of high-valent intermediates in water oxidation

DOE PAGES

Nguyen, Andy I.; Wang, Jianing; Levine, Daniel S.; ...

2017-04-07

The oxo-cobalt cubane unit [Co 4O 4] is of interest as a homogeneous oxygen-evolution reaction (OER) catalyst, and as a functional mimic of heterogeneous cobalt oxide OER catalysts. The synthesis of several new cubanes allows evaluation of redox potentials for the [Co 4O 4] cluster, which are highly sensitive to the ligand environment and span a remarkable range of 1.42 V. The [Co III 4O 4] 4+/[Co III 3Co IVO 4 ]5+ and [Co III 3Co IVO 4] 5+/[Co III 2Co IV 2O 4] 6+ redox potentials are reliably predicted by the pKas of the ligands. Hydrogen bonding is alsomore » shown to significantly raise the redox potentials, by ~500 mV. The potential-p K a correlation is used to evaluate the feasibility of various proposed OER catalytic intermediates, including high-valent Co-oxo species. The synthetic methods and structure–reactivity relationships developed by these studies should better guide the design of new cubane-based OER catalysts.« less

Latvian Waste Management Modelling in View of Environmental Impact Reduction / Latvijas Atkritumu SAIMNIECĪBAS ATTĪSTĪBA un TĀS RADĪTĀS Ietekmes UZ Vidi SAMAZINĀŠANAS MODELĒŠANA

NASA Astrophysics Data System (ADS)

Teibe, I.; Bendere, R.; Arina, D.

2013-12-01

In the work, the life-cycle assessment approach is applied to the planning of waste management development in a seaside region (Piejūra) using the Waste Management Planning System (WAMPS) program. In Latvia, the measures to be taken for the climate change mitigation are of utmost importance - especially as related to the WM performance, since a disposal of biodegradable waste presents the primary source of GHG emissions. To reduce the amount of such waste is therefore one of the most significant goals in the State WM plan for 2013-2020, whose adoption is the greatest challenge for municipalities. The authors analyse seven models which involve widely employed biomass processing methods, are based on experimental data and intended for minimising the direct disposal of organic mass at the solid waste landfills. The numerical results obtained evidence that the thermal or biotechnological treatment of organic waste substantially reduces the negative environmental impact of WM practices - by up to 6% as compared with the currently existing. Klimata pārmaiņu samazināšanas pasākumi Latvijā atkritumu saimniecības sektorā ir īpaši svarīgi. jo bioloģiski sadalāmo atkritumu apglabāšana ir viens no būtiskākajiem SEG emisiju avotiem valstī. Pētījumā modelēti virkne sadzīves atkritumu apsaimniekošanas modeļi. kas ietver plašāk izmantotās biomasas pārstrādes metodes un samazina tiešu organiskās masas apglabāšanu cieto sadzīves atkritumu poligonos. Atkritumu apsaimniekošanas modeļu radītās vides ietekmes novērtēšanai izmantota WAMPS (Waste Management Planning System) programma, kas balstīta uz atkritumu apsaimniekošanas procesu dzīves cikla novērtējumu vienā no desmit Latvijas atkritumu apsaimniekošanas reģioniem - Piejūra. Iegūtie kvantitatīvie rezultāti norāda. ka organiskās atkritumu masas pārstrāde un stabilizēšana, izmantojot biotehnoloģijas vai termisko pārstrādi, būtiski samazina atkritumu apsaimniekošanas rad

Evaluation of vaccines in the EU TB Vaccine Cluster using a guinea pig aerosol infection model of tuberculosis.

PubMed

Williams, Ann; Hatch, Graham J; Clark, Simon O; Gooch, Karen E; Hatch, Kim A; Hall, Graham A; Huygen, Kris; Ottenhoff, Tom H M; Franken, Kees L M C; Andersen, Peter; Doherty, T Mark; Kaufmann, Stefan H E; Grode, Leander; Seiler, Peter; Martin, Carlos; Gicquel, Brigitte; Cole, Stewart T; Brodin, Priscille; Pym, Alexander S; Dalemans, Wilfried; Cohen, Joe; Lobet, Yves; Goonetilleke, Nilu; McShane, Helen; Hill, Adrian; Parish, Tanya; Smith, Debbie; Stoker, Neil G; Lowrie, Douglas B; Källenius, Gunilla; Svenson, Stefan; Pawlowski, Andrzej; Blake, Karen; Marsh, Philip D

2005-01-01

The TB Vaccine Cluster project funded by the EU Fifth Framework programme aims to provide novel vaccines against tuberculosis that are suitable for evaluation in humans. This paper describes the studies of the protective efficacy of vaccines in a guinea pig aerosol-infection model of primary tuberculosis. The objective was to conduct comparative evaluations of vaccines that had previously demonstrated efficacy in other animal models. Groups of 6 guinea pigs were immunized with vaccines provided by the relevant EU Vaccine Cluster partners. Survival over 17 or 26 weeks was used as the principal measure of vaccine efficacy following aerosol challenge with H37Rv. Counts of mycobacteria in lungs and spleens, and histopathological changes in the lungs, were also used to provide evidence of protection. A total of 24 vaccines were evaluated in 4 experiments each of a different design. A heterologous prime-boost strategy of DNA and MVA, each expressing Ag85A and a fusion protein of ESAT-6 and Ag85B in adjuvant, protected the guinea pigs to the same extent as BCG. Genetically modified BCG vaccines and boosted BCG strategies also protected guinea pigs to the same extent as BCG but not statistically significantly better. A relatively high aerosol-challenge dose and evaluation over a protracted time post-challenge allowed superior protection over BCG to be demonstrated by BCG boosted with MVA and fowl pox vectors expressing Ag85A.

A Novel ESX-1 Locus Reveals that Surface-Associated ESX-1 Substrates Mediate Virulence in Mycobacterium marinum

PubMed Central

Kennedy, George M.; Hooley, Gwendolyn C.; Champion, Matthew M.; Mba Medie, Felix

2014-01-01

EsxA (ESAT-6) and EsxB (CFP-10) are virulence factors exported by the ESX-1 system in mycobacterial pathogens. In Mycobacterium marinum, an established model for ESX-1 secretion in Mycobacterium tuberculosis, genes required for ESX-1 export reside at the extended region of difference 1 (RD1) locus. In this study, a novel locus required for ESX-1 export in M. marinum was identified outside the RD1 locus. An M. marinum strain bearing a transposon-insertion between the MMAR_1663 and MMAR_1664 genes exhibited smooth-colony morphology, was deficient for ESX-1 export, was nonhemolytic, and was attenuated for virulence. Genetic complementation revealed a restoration of colony morphology and a partial restoration of virulence in cell culture models. Yet hemolysis and the export of ESX-1 substrates into the bacteriological medium in vitro as measured by both immunoblotting and quantitative proteomics were not restored. We show that genetic complementation of the transposon insertion strain partially restored the translocation of EsxA and EsxB to the mycobacterial cell surface. Our findings indicate that the export of EsxA and EsxB to the cell surface, rather than secretion into the bacteriological medium, correlates with virulence in M. marinum. Together, these findings not only expand the known genetic loci required for ESX-1 secretion in M. marinum but also provide an explanation for the observed disparity between in vitro ESX-1 export and virulence. PMID:24610712

Mycobacterium komaniense sp. nov., a rapidly growing non-tuberculous Mycobacterium species detected in South Africa.

PubMed

Gcebe, Nomakorinte; Rutten, Victor P M G; van Pittius, Nicolaas Gey; Naicker, Brendon; Michel, Anita L

2018-05-01

Some species of non-tuberculous mycobacteria (NTM) have been reported to be opportunistic pathogens of animals and humans. Recently there has been an upsurge in the number of cases of NTM infections, such that some NTM species are now recognized as pathogens of humans and animals. From a veterinary point of view, the major significance of NTM is the cross-reactive immune response they elicit against Mycobacterium bovis antigens, leading to misdiagnosis of bovine tuberculosis. Four NTM isolates were detected from a bovine nasal swab, soil and water, during an NTM survey in South Africa. These were all found using 16S rRNA gene sequence analysis to be closely related to Mycobacterium moriokaense. The isolates were further characterised by sequence analysis of the partial fragments of hsp65, rpoB and sodA. The genome of the type strain was also elucidated. Gene (16S rRNA, hsp65, rpoB and sodA) and protein sequence data analysis of 6 kDa early secretory antigenic target (ESAT 6) and 10 kDa culture filtrate protein (CFP-10) revealed that these isolates belong to a unique Mycobacterium species. Differences in phenotypic and biochemical traits between the isolates and closely related species further supported that these isolates belong to novel Mycobacterium species. We proposed the name Mycobacterium komaniense sp. nov. for this new species. The type strain is GPK 1020 T (=CIP 110823T=ATCC BAA-2758).

Gene Expression Profile and Immunological Evaluation of Unique Hypothetical Unknown Proteins of Mycobacterium leprae by Using Quantitative Real-Time PCR

PubMed Central

Prithiviraj, Kalyani; Groathouse, Nathan; Brennan, Patrick J.; Spencer, John S.

2013-01-01

The cell-mediated immunity (CMI)-based in vitro gamma interferon release assay (IGRA) of Mycobacterium leprae-specific antigens has potential as a promising diagnostic means to detect those individuals in the early stages of M. leprae infection. Diagnosis of leprosy is a major obstacle toward ultimate disease control and has been compromised in the past by the lack of specific markers. Comparative bioinformatic analysis among mycobacterial genomes identified potential M. leprae-specific proteins called “hypothetical unknowns.” Due to massive gene decay and the prevalence of pseudogenes, it is unclear whether any of these proteins are expressed or are immunologically relevant. In this study, we performed cDNA-based quantitative real-time PCR to investigate the expression status of 131 putative open reading frames (ORFs) encoding hypothetical unknowns. Twenty-six of the M. leprae-specific antigen candidates showed significant levels of gene expression compared to that of ESAT-6 (ML0049), which is an important T cell antigen of low abundance in M. leprae. Fifteen of 26 selected antigen candidates were expressed and purified in Escherichia coli. The seroreactivity to these proteins of pooled sera from lepromatous leprosy patients and cavitary tuberculosis patients revealed that 9 of 15 recombinant hypothetical unknowns elicited M. leprae-specific immune responses. These nine proteins may be good diagnostic reagents to improve both the sensitivity and specificity of detection of individuals with asymptomatic leprosy. PMID:23239802

Endeavour update: a web resource for gene prioritization in multiple species

PubMed Central

Tranchevent, Léon-Charles; Barriot, Roland; Yu, Shi; Van Vooren, Steven; Van Loo, Peter; Coessens, Bert; De Moor, Bart; Aerts, Stein; Moreau, Yves

2008-01-01

Endeavour (http://www.esat.kuleuven.be/endeavourweb; this web site is free and open to all users and there is no login requirement) is a web resource for the prioritization of candidate genes. Using a training set of genes known to be involved in a biological process of interest, our approach consists of (i) inferring several models (based on various genomic data sources), (ii) applying each model to the candidate genes to rank those candidates against the profile of the known genes and (iii) merging the several rankings into a global ranking of the candidate genes. In the present article, we describe the latest developments of Endeavour. First, we provide a web-based user interface, besides our Java client, to make Endeavour more universally accessible. Second, we support multiple species: in addition to Homo sapiens, we now provide gene prioritization for three major model organisms: Mus musculus, Rattus norvegicus and Caenorhabditis elegans. Third, Endeavour makes use of additional data sources and is now including numerous databases: ontologies and annotations, protein–protein interactions, cis-regulatory information, gene expression data sets, sequence information and text-mining data. We tested the novel version of Endeavour on 32 recent disease gene associations from the literature. Additionally, we describe a number of recent independent studies that made use of Endeavour to prioritize candidate genes for obesity and Type II diabetes, cleft lip and cleft palate, and pulmonary fibrosis. PMID:18508807

Use of recombinant purified protein derivative (PPD) antigens as specific skin test for tuberculosis.

PubMed

Stavri, Henriette; Bucurenci, Nadia; Ulea, Irina; Costache, Adriana; Popa, Loredana; Popa, Mircea Ioan

2012-11-01

Purified protein derivative (PPD) is currently the only available skin test reagent used worldwide for the diagnosis of tuberculosis (TB). The aim of this study was to develop a Mycobacterium tuberculosis specific skin test reagent, without false positive results due to Bacillus Calmette-Guerin (BCG) vaccination using recombinant antigens. Proteins in PPD IC-65 were analyzed by tandem mass spectrometry and compared to proteins in M. tuberculosis culture filtrate; 54 proteins were found in common. Top candidates MPT64, ESAT 6, and CFP 10 were overexpressed in Escherichia coli expression strains and purified as recombinant proteins. To formulate optimal immunodiagnostic PPD cocktails, the antigens were evaluated by skin testing guinea pigs sensitized with M. tuberculosis H37Rv and BCG. For single antigens and a cocktail mixture of these antigens, best results were obtained using 3 μg/0.1 ml, equivalent to 105 TU (tuberculin units). Each animal was simultaneously tested with PPD IC-65, 2 TU/0.1 ml, as reference. Reactivity of the multi-antigen cocktail was greater than that of any single antigen. The skin test results were between 34.3 and 76.6 per cent the level of reactivity compared to that of the reference when single antigens were tested and 124 per cent the level of reactivity compared to the reference for the multi-antigen cocktail. Our results showed that this specific cocktail could represent a potential candidate for a new skin diagnostic test for TB.

The Effect of Orthology and Coregulation on Detecting Regulatory Motifs

PubMed Central

Storms, Valerie; Claeys, Marleen; Sanchez, Aminael; De Moor, Bart; Verstuyf, Annemieke; Marchal, Kathleen

2010-01-01

Background Computational de novo discovery of transcription factor binding sites is still a challenging problem. The growing number of sequenced genomes allows integrating orthology evidence with coregulation information when searching for motifs. Moreover, the more advanced motif detection algorithms explicitly model the phylogenetic relatedness between the orthologous input sequences and thus should be well adapted towards using orthologous information. In this study, we evaluated the conditions under which complementing coregulation with orthologous information improves motif detection for the class of probabilistic motif detection algorithms with an explicit evolutionary model. Methodology We designed datasets (real and synthetic) covering different degrees of coregulation and orthologous information to test how well Phylogibbs and Phylogenetic sampler, as representatives of the motif detection algorithms with evolutionary model performed as compared to MEME, a more classical motif detection algorithm that treats orthologs independently. Results and Conclusions Under certain conditions detecting motifs in the combined coregulation-orthology space is indeed more efficient than using each space separately, but this is not always the case. Moreover, the difference in success rate between the advanced algorithms and MEME is still marginal. The success rate of motif detection depends on the complex interplay between the added information and the specificities of the applied algorithms. Insights in this relation provide information useful to both developers and users. All benchmark datasets are available at http://homes.esat.kuleuven.be/~kmarchal/Supplementary_Storms_Valerie_PlosONE. PMID:20140085

Biorefinery Technologies for Biomass Conversion Into Chemicals and Fuels Towards Zero Emissions (Review) / Nulles Emisiju Princips Biomasas Konversijas Tehnoloģijās Aizstājot Fosilos Resursus (Pārskata Raksts)

NASA Astrophysics Data System (ADS)

Gravitis, J.; Abolins, J.

2013-10-01

Exhausting of world resources, increasing pollution, and climate change are compelling the shift of the world economy from continuous growth to a kind of economy based on integration of technologies into zero emissions production systems. Transition from non-renewable fossil resources to renewable resources provided by solar radiation and the current processes in biosphere is seen in the bio-refinery approach - replacing crude oil refineries by biomass refineries. Biotechnology and nano-technologies are getting accepted as important players along with conventional biomass refinery technologies. Systems design is a significant element in the integration of bio-refinery technologies in clusters. A number of case-studies, steam explosion auto-hydrolysis (SEA) in particular, are reviewed to demonstrate conversion of biomass into value-added chemicals and fuels. Analysis of energy flows is made as part of modelling the SEA processes, the eMergy (energy memory) approach and sustainability indices being applied to assess environmental impacts. Resursu izsīkums, vides piesārņojums un globāla mēroga klimatiskās izmaiņas ir civilizācijas izdzīvošanai būtiski faktori, kas virza pasaules ekonomikas pārmaiņas, atsakoties no nepārtrauktas izaugsmes idejas par labu tādai ekonomikai, kas balstās uz atjaunojošamies resursiem un dažādu tehnoloģiju integrācijemisiju principam atbilstošās ražošanas sistēmās. Saules radiācijas ierosinātajos planētas biosfērā notiekošajos procesos radīto organisko vielu pārstrādes kompleksi, kas operē ievērojot sabalansētu nulles emisiju principu, tiek uzlūkoti kā tās ekonomiskās (ražošanas) struktūras, kurām jānodrošina pāreja uz atjaunojošos resursu izmantošanu, aizstājot esošās fosilo resursu (naftas, ogļu) pārstrādes rūpnīcas. Līdzās jau apgūtajām biomasas rafinēšanas tehnoloģijām svarīga un pieaugoša loma ekonomiskās sistēmas resursu bāzes nomaiņā ir bio- un nanotehnolo

Influence of affinity on antibody determination in microtiter ELISA systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterman, J.H.; Voss, E.W. Jr.; Butler, J.E.

1986-03-01

Theoretically, all immunoassays are affinity (Ka) dependent when the product of the antibody (Ab) Ka and the free epitope concentration is less than 10. Thus, the degree of dependence on Ka depends on the concentration of available antigen in the system. The authors examined the binding of /sup 125/I-anti-fluorescein (a-FLU) monoclonal antibodies of different affinities to FLU-gelatin adsorbed on Immunlon 2 microtiter plates. Data obtained were in general agreement with our theoretical predictions; the percent of /sup 125/I-a-FLU which bound correlated with Ka, as did the shape of the titration curves. Measurement of 5 a-FLU monoclonals by the ELISA showedmore » that the determination of Ab concentrations depends on the FLU-gelatin concentration, epitope density, and on the relationship between the Kas of test samples and the reference standard Ab preparation. Thus the ELISA is Ka dependent and should not be used routinely to estimate the absolute amount to Ab in unknown samples. However, the Ka dependency of the ELISA might provide a convenient assay for the estimation of the relative functional Ka (rfKa) of antibody preparations.« less

Hydrothermal growth of potassium titanyl arsenate (KTA) in large autoclaves

NASA Astrophysics Data System (ADS)

Belt, Roger F.; Ings, John B.

1993-03-01

Solubility and phase relations were investigated for selected K/As ratios in KH2AsO4-KOH solutions at 600°C and 2040 atm. All initial data were obtained with 5 mm diameter x 50 mm long platinum capsules in Tem-Pres type autoclaves. The most favorable results were repeated in Morey type autoclaves of 2.2 cm diameter. The P-V-T data were generated and extrapolated for use in gold liners and René 41 autoclaves with a pressure balancing method. Transfer to the 3.8 cm diameter x 46 cm long autoclaves with gold liners was achieved. Both nutrient and larger seed crystals were grown from a K2WO4-Li2WO4 flux. The internal and external degrees of fill were adjusted to obtain a balance of pressure at 1700 atm and 590°C. Initial growth runs were made for 1-2 weeks under a gradient of 30°C with a 4 molar KH2AsO4 mineralizer. Natural facet seeds were employed first while later runs utilized (011) cut and polished seeds.

Immunogenicity and protective efficacy of heterologous prime-boost regimens with mycobacterial vaccines and recombinant adenovirus- and poxvirus-vectored vaccines against murine tuberculosis.

PubMed

You, Qingrui; Wu, Yongge; Wu, Yang; Wei, Wei; Wang, Changyong; Jiang, Dehua; Yu, Xianghui; Zhang, Xizhen; Wang, Yong; Tang, Zhijiao; Jiang, Chunlai; Kong, Wei

2012-11-01

To evaluate regimens using bacillus Calmette-Guérin (BCG) or recombinant BCG (rBCG) overexpressing Ag85B for priming, followed by boosting with a modified vaccinia virus Ankara strain (MVA) and/or adenovirus vector (AD) expressing an Ag85B-ESAT6 fusion protein. Cellular and humoral immune responses were determined after subcutaneous vaccination, which was employed to trigger systemic immunity against intravenous infection in a mouse model of tuberculosis (TB). Bacterial loads and lung histology were evaluated. The relative IgG2a and IgG1 antibody levels indicated that the viral-vectored vaccines generated a T-helper type 1 (Th1)-biased response after two doses of viral boost vaccinations. Boosting BCG-primed mice with viral vaccines induced a Th1 immune response that included both CD4 and CD8 T-cells generating antigen-specific interferon-gamma (IFN-γ) and CD8 T cytotoxic activity. Only mice vaccinated with two different viral boosters after BCG priming exhibited a significant reduction in bacterial burden in the lung after challenge. Histology examinations confirmed the attenuation of lung damage and more compact granulomas. After mycobacteria priming, boosting with AD85B-E6 followed by MVA85B-E6 afforded better protection than the reverse order of administration of the viral vectors. This study demonstrates the potential of multiple heterologous viral booster vaccines, although the exact correlates of protection and optimal regimens should be further investigated for the rational design of future vaccine strategies. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Secretome profile analysis of multidrug-resistant, monodrug-resistant and drug-susceptible Mycobacterium tuberculosis.

PubMed

Putim, Chanyanuch; Phaonakrop, Narumon; Jaresitthikunchai, Janthima; Gamngoen, Ratikorn; Tragoolpua, Khajornsak; Intorasoot, Sorasak; Anukool, Usanee; Tharincharoen, Chayada Sitthidet; Phunpae, Ponrut; Tayapiwatana, Chatchai; Kasinrerk, Watchara; Roytrakul, Sittiruk; Butr-Indr, Bordin

2018-03-01

The emergence of drug-resistant tuberculosis has generated great concern in the control of tuberculosis and HIV/TB patients have established severe complications that are difficult to treat. Although, the gold standard of drug-susceptibility testing is highly accurate and efficient, it is time-consuming. Diagnostic biomarkers are, therefore, necessary in discriminating between infection from drug-resistant and drug-susceptible strains. One strategy that aids to effectively control tuberculosis is understanding the function of secreting proteins that mycobacteria use to manipulate the host cellular defenses. In this study, culture filtrate proteins from Mycobacterium tuberculosis H37Rv, isoniazid-resistant, rifampicin-resistant and multidrug-resistant strains were gathered and profiled by shotgun-proteomics technique. Mass spectrometric analysis of the secreted proteome identified several proteins, of which 837, 892, 838 and 850 were found in M. tuberculosis H37Rv, isoniazid-resistant, rifampicin-resistant and multidrug-resistant strains, respectively. These proteins have been implicated in various cellular processes, including biological adhesion, biological regulation, developmental process, immune system process localization, cellular process, cellular component organization or biogenesis, metabolic process, and response to stimulus. Analysis based on STITCH database predicted the interaction of DNA topoisomerase I, 3-oxoacyl-(acyl-carrier protein) reductase, ESAT-6-like protein, putative prophage phiRv2 integrase, and 3-phosphoshikimate 1-carboxyvinyltransferase with isoniazid, rifampicin, pyrazinamide, ethambutol and streptomycin, suggesting putative roles in controlling the anti-tuberculosis ability. However, several proteins with no interaction with all first-line anti-tuberculosis drugs might be used as markers for mycobacterial identification.

Light, shadows and surface characteristics: the multispectral Portable Light Dome

NASA Astrophysics Data System (ADS)

Watteeuw, Lieve; Hameeuw, Hendrik; Vandermeulen, Bruno; Van der Perre, Athena; Boschloos, Vanessa; Delvaux, Luc; Proesmans, Marc; Van Bos, Marina; Van Gool, Luc

2016-11-01

A multispectral, multidirectional, portable and dome-shaped acquisition system is developed within the framework of the research projects RICH (KU Leuven) and EES (RMAH, Brussels) in collaboration with the ESAT-VISICS research group (KU Leuven). The multispectral Portable Light Dome (MS PLD) consists of a hemispherical structure, an overhead camera and LEDs emitting in five parts of the electromagnetic spectrum regularly covering the dome's inside surface. With the associated software solution, virtual relighting and enhancements can be applied in a real-time, interactive manner. The system extracts genuine 3D and shading information based on a photometric stereo algorithm. This innovative approach allows for instantaneous alternations between the computations in the infrared, red, green, blue and ultraviolet spectra. The MS PLD system has been tested for research ranging from medieval manuscript illuminations to ancient Egyptian artefacts. Preliminary results have shown that it documents and measures the 3D surface structure of objects, re-visualises underdrawings, faded pigments and inscriptions, and examines the MS results in combination with the actual relief characteristics of the physical object. Newly developed features are reflection maps and histograms, analytic visualisations of the reflection properties of all separate LEDs or selected areas. In its capacity as imaging technology, the system acts as a tool for the analysis of surface materials (e.g. identification of blue pigments, gold and metallic surfaces). Besides offering support in answering questions of attribution and monitoring changes and decay of materials, the PLD also contributes to the identification of materials, all essential factors when making decisions in the conservation protocol.

Discovery of the type VII ESX-1 secretion needle?

PubMed

Ates, Louis S; Brosch, Roland

2017-01-01

Mycobacterium tuberculosis, the etiological agent of human tuberculosis, harbours five ESAT-6/type VII secretion (ESX/T7S) systems. The first esx gene clusters were identified during the genome-sequencing project of M. tuberculosis H37Rv. Follow-up studies revealed additional genes playing important roles in ESX/T7S systems. Among the latter genes, one can find those that encode Pro-Glu (PE) and Pro-Pro-Glu (PPE) proteins as well as a gene cluster that is encoded >260 kb upstream of the esx-1 locus and encodes ESX-1 secretion-associated proteins EspA (Rv3616c), EspC (Rv3615c) and EspD (Rv3614c). The espACD cluster has been suggested to have an important function in ESX-1 secretion since EspA-EspC and EsxA-EsxB are mutually co-dependent on each other for secretion. However, the molecular mechanism of this co-dependence and interaction between the substrates remained unknown. In this issue of Molecular Microbiology, Lou and colleagues show that EspC forms high-molecular weight polymerization complexes that resemble selected components of type II, III and/or IV secretion systems of Gram-negative bacteria. Indeed, EspC-multimeric complexes form filamentous structures that could well represent a secretion needle of ESX-1 type VII secretion systems. This exciting observation opens new avenues for research to discover and characterize ESX/T7S components and elucidates the co-dependence of EsxA/B secretion with EspA/C. © 2016 John Wiley & Sons Ltd.

The role of pattern recognition receptors in lung sarcoidosis.

PubMed

Mortaz, Esmaeil; Adcock, Ian M; Abedini, Atefhe; Kiani, Arda; Kazempour-Dizaji, Mehdi; Movassaghi, Masoud; Garssen, Johan

2017-08-05

Sarcoidosis is a granulomatous disorder of unknown etiology. Infection, genetic factors, autoimmunity and an aberrant innate immune system have been explored as potential causes of sarcoidosis. The etiology of sarcoidosis remains unknown, and it is thought that it might be caused by an infectious agent in a genetically predisposed, susceptible host. Inflammation results from recognition of evolutionarily conserved structures of pathogens (Pathogen-associated molecular patterns, PAMPs) and/or from reaction to tissue damage associated patterns (DAMPs) through recognition by a limited number of germ line-encoded pattern recognition receptors (PRRs). Due to the similar clinical and histopathological picture of sarcoidosis and tuberculosis, Mycobacterium tuberculosis antigens such early secreted antigen (ESAT-6), heat shock proteins (Mtb-HSP), catalase-peroxidase (katG) enzyme and superoxide dismutase A peptide (sodA) have been often considered as factors in the etiopathogenesis of sarcoidosis. Potential non-TB-associated PAMPs include lipopolysaccharide (LPS) from the outer membrane of Gram-negative bacteria, peptidoglycan, lipoteichoic acid, bacterial DNA, viral DNA/RNA, chitin, flagellin, leucine-rich repeats (LRR), mannans in the yeast cell wall, and microbial HSPs. Furthermore, exogenous non-organic antigens such as metals, silica, pigments with/without aluminum in tattoos, pesticides, and pollen have been evoked as potential causes of sarcoidosis. Exposure of the airways to diverse infectious and non-infectious agents may be important in the pathogenesis of sarcoidosis. The current review provides and update on the role of PPRs and DAMPs in the pathogenesis of sarcoidsis. Copyright © 2017 Elsevier B.V. All rights reserved.

HIV infection impairs Th1 and Th17 Mycobacterium tuberculosis-specific T cell responses

PubMed Central

Murray, Lyle W; Satti, Iman; Meyerowitz, Jodi; Jones, Matthew; Willberg, Christian B; Ussher, James E; Goedhals, Dominique; Hurst, Jacob; Phillips, Rodney E; McShane, Helen

2018-01-01

Background HIV-infected individuals have a higher risk of developing active tuberculosis than HIV-uninfected individuals, but the mechanisms underpinning this are unclear. We hypothesized that depletion of specific components of Mycobacterium tuberculosis (M.tb)-specific CD4+ and CD8+ T cell responses contributed to this increased risk. Methods M.tb-specific T cell responses in 147 HIV-infected and 44 HIV-uninfected control subjects in a TB-endemic setting in Bloemfontein, South Africa were evaluated. Using a whole-blood flow cytometry assay, we measured expression of IFNγ, TNFα, IL-2 and IL-17 in CD4+ and CD8+ T cells in response to M.tb antigens (PPD, ESAT-6/CFP-10 (EC) and DosR regulon-encoded α-crystallin (Rv2031c)). Results Fewer HIV-infected individuals had detectable CD4+ and CD8+ T cell responses to PPD and Rv2031c than HIV-uninfected subjects. M.tb-specific T cells showed distinct patterns of cytokine expression comprising both Th1 (CD4 and CD8) and Th17 (CD4) cytokines, the latter at highest frequency for Rv2031c. Th17 antigen-specific responses to all antigens tested were specifically impaired in HIV-infected individuals. Conclusions HIV-associated impairment of CD4+ and CD8+ M.tb-specific T cell responses is antigen-specific, particularly impacting responses to PPD and Rv2031c. Preferential depletion of Th17 cytokine-expressing CD4+ T cells suggests this T cell subset may be key to TB susceptibility in HIV-infected individuals. PMID:29546381

Prolonged intervals during Mycobacterium tuberculosis subunit vaccine boosting contributes to eliciting immunity mediated by central memory-like T cells.

PubMed

Bai, Chunxiang; He, Juanjuan; Niu, Hongxia; Hu, Lina; Luo, Yanping; Liu, Xun; Peng, Liang; Zhu, Bingdong

2018-05-01

It is believed that central memory T cells (T CM ) provide long-term protection against tuberculosis (TB). However, the effects of TB subunit vaccine immunization schedule, especially the vaccination intervals, on T cell immune memory is still unclear. In this study, mice were immunized with fusion protein ESAT6-Ag85B-MPT64 (190-198)-Mtb8.4-Rv2626c (LT70) based subunit vaccine three times according to the following schedules: ① 0, 3rd and 6th week respectively (0-3-6w), ② 0, 4th and 12th week (0-4-12w), and ③ 0, 4th and 24th week (0-4-24w). We found that both schedules of 0-4-12w and 0-4-24w induced higher level of antigen specific IL-2, IFN-γ and TNF-α than 0-3-6w immunization. Among them, 0-4-12w induced the highest level of IL-2, which is a key cytokine mainly produced by T CM . Moreover, by cultured IFN-γ ELISPOT and cell proliferation assay etc., we found that the vaccination schedule of 0-4-12w elicited higher numbers of T CM like cells, stronger T CM - mediated immune responses and higher protective efficacy against M. bovis BCG challenge than 0-3-6w did. It suggests that prolonging the vaccination interval of TB subunit vaccine to some extent contributes to inducing more abundant T CM like cells and providing stronger immune protection against mycobacteria infection. Copyright © 2018. Published by Elsevier Ltd.

Differences in IgG responses against infection phase related Mycobacterium tuberculosis (Mtb) specific antigens in individuals exposed or not to Mtb correlate with control of TB infection and progression.

PubMed

Coppola, Mariateresa; Arroyo, Leonar; van Meijgaarden, Krista E; Franken, Kees Lmc; Geluk, Annemieke; Barrera, Luis F; Ottenhoff, Tom H M

2017-09-01

Tuberculosis (TB) occurs in only 3-10% of Mycobacterium tuberculosis (Mtb) infected individuals, suggesting that natural immunity can contain Mtb infection, although this remains poorly understood. Next to T-cells, a potentially protective role for B-cells and antibodies has emerged recently. However, the Mtb antigens involved remain ill-defined. Here, we investigated in a TB-endemic setting IgG levels against 15 Mtb antigens, representing various phases of Mtb infection and known to be potent human T-cell antigens. IgG levels against ESAT6/CFP10, Rv0440, Rv0867c, Rv1737c, Rv2029c, Rv2215, Rv2389c, Rv3616c and Mtb purified protein derivative (PPD) were higher in TB patients than in endemic and non-endemic controls. The only exception was Rv1733c that was preferentially recognized by antibodies from endemic controls compared to TB patients and non-endemic controls, suggesting a potential correlation with control of TB infection and progression. In patients, IgG levels against Ag85B and Rv2029c correlated with Mtb loads, while immunoglobulins against Rv0440 differed between genders. Our results support the potential role of certain Mtb antigen-(Rv1733c) specific antibodies in the control of TB infection and progression, while other Mtb antigen-specific antibodies correlate with TB disease activity and bacillary loads. The findings for Rv1733c agree with previous T-cell results and have implications for including antibody-mediated immunity in designing new strategies to control TB. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A pH-dependent conformational ensemble mediates proton transport through the influenza A/M2 protein†

PubMed Central

Polishchuk, Alexei L.; Lear, James D.; Ma, Chunlong; Lamb, Robert A.; Pinto, Lawrence H.; DeGrado, William F.

2010-01-01

The influenza A M2 protein exhibits inwardly rectifying, pH-activated proton transport that saturates at low pH. A comparison of high-resolution structures of the transmembrane domain at high and low pH suggests that pH-dependent conformational changes may facilitate proton conduction by alternately changing the accessibility of the N-terminal and C-terminal regions of the channel as a proton transits through the transmembrane domain. Here, we show that M2 functionally reconstituted in liposomes populates at least three different conformational states over a physiologically relevant pH range, with transition midpoints that are consistent with previously reported His37 pKas. We then develop and test two similar, quantitative mechanistic models of proton transport, where protonation shifts the equilibrium between structural states having different proton affinities and solvent accessibilities. The models account well for a collection of experimental data sets over a wide range of pHs and voltages and require only a small number of adjustable parameters to accurately describe the data. While the kinetic models do not require any specific conformation for the protein, they nevertheless are consistent with a large body of structural information based on high-resolution NMR and crystallographic structures, optical spectroscopy, and MD calculations. PMID:20968306

Correlates of caregiver burden among family caregivers of older Korean Americans.

PubMed

Casado, Banghwa; Sacco, Paul

2012-05-01

Despite the rapid growth of older ethnic minority populations, knowledge is limited about informal caregiving among these groups. Our aim was to identify correlates of caregiver burden among family caregivers of older Korean Americans (KAs). A cross-sectional survey collected data from 146 KA caregivers. Using a modified stress-appraisal model, we examined background and context characteristics (caregiver sex, relationship to care recipient, college education, English proficiency, time in caregiving role, family support network, friend support network), a primary stressor (care recipient functional dependency), a primary appraisal (caregiving hours), and resources (family agreement, care management self-efficacy, service use self-efficacy) as potential correlates of caregiver burden. Interactions between the primary stressor, primary appraisal, and resources were also tested. Being female and the care recipient's spouse were associated with higher burden. Conversely, a larger family support network, greater family agreement, and greater care management self-efficacy were associated with lower burden. A significant interaction was detected between functional dependency and family agreement; higher levels of family agreement moderated the association between care recipient functional dependency and caregiver burden. Interventions to reduce caregiver burden in KA caregivers may be more effective if they include approaches specifically designed to build family support, improve family agreement, and increase caregivers' self-efficacy.

Hierarchical nuclear and cytoplasmic genetic architectures for plant growth and defense within Arabidopsis.

PubMed

Joseph, Bindu; Corwin, Jason A; Züst, Tobias; Li, Baohua; Iravani, Majid; Schaepman-Strub, Gabriela; Turnbull, Lindsay A; Kliebenstein, Daniel J

2013-06-01

To understand how genetic architecture translates between phenotypic levels, we mapped the genetic architecture of growth and defense within the Arabidopsis thaliana Kas × Tsu recombinant inbred line population. We measured plant growth using traditional size measurements and size-corrected growth rates. This population contains genetic variation in both the nuclear and cytoplasmic genomes, allowing us to separate their contributions. The cytoplasmic genome regulated a significant variance in growth but not defense, which was due to cytonuclear epistasis. Furthermore, growth adhered to an infinitesimal model of genetic architecture, while defense metabolism was more of a moderate-effect model. We found a lack of concordance between quantitative trait loci (QTL) regulating defense and those regulating growth. Given the published evidence proving the link between glucosinolates and growth, this is likely a false negative result caused by the limited population size. This size limitation creates an inability to test the entire potential genetic landscape possible between these two parents. We uncovered a significant effect of glucosinolates on growth once we accounted for allelic differences in growth QTLs. Therefore, other growth QTLs can mask the effects of defense upon growth. Investigating direct links across phenotypic hierarchies is fraught with difficulty; we identify issues complicating this analysis.

Some Properties and Uses of Torsional Overlap Integrals

NASA Astrophysics Data System (ADS)

Mekhtiev, Mirza A.; Hougen, Jon T.

1998-01-01

The first diagonalization step in a rho-axis-method treatment of methyl-top internal rotation problems involves finding eigenvalues and eigenvectors of a torsional Hamiltonian, which depends on the rotational projection quantum numberKas a parameter. Traditionally the torsional quantum numbervt= 0, 1, 2···is assigned to eigenfunctions of givenKin order of increasing energy. In this paper we propose an alternative labeling scheme, using the torsional quantum numbervT, which is based on properties of theK-dependent torsional overlap integrals . In particular, the quantum numbervTis assigned in such a way that torsional wavefunctions |vT,K> vary as slowly as possible whenKchanges by unity. Roughly speaking,vT=vtfor torsional levels below the barrier, whereasvTis more closely related to the free-rotor quantum number for levels above the barrier. Because of the latter fact, we believevTwill in general be a physically more meaningful torsional quantum number for levels above the barrier. The usefulness of overlap integrals for qualitative prediction of torsion-rotation band intensities and for rationalizing the magnitudes of perturbations involving some excitation of the small-amplitude vibrations in an internal rotor problem is also discussed.

Hierarchical Nuclear and Cytoplasmic Genetic Architectures for Plant Growth and Defense within Arabidopsis[C][W

PubMed Central

Joseph, Bindu; Corwin, Jason A.; Züst, Tobias; Li, Baohua; Iravani, Majid; Schaepman-Strub, Gabriela; Turnbull, Lindsay A.; Kliebenstein, Daniel J.

2013-01-01

To understand how genetic architecture translates between phenotypic levels, we mapped the genetic architecture of growth and defense within the Arabidopsis thaliana Kas × Tsu recombinant inbred line population. We measured plant growth using traditional size measurements and size-corrected growth rates. This population contains genetic variation in both the nuclear and cytoplasmic genomes, allowing us to separate their contributions. The cytoplasmic genome regulated a significant variance in growth but not defense, which was due to cytonuclear epistasis. Furthermore, growth adhered to an infinitesimal model of genetic architecture, while defense metabolism was more of a moderate-effect model. We found a lack of concordance between quantitative trait loci (QTL) regulating defense and those regulating growth. Given the published evidence proving the link between glucosinolates and growth, this is likely a false negative result caused by the limited population size. This size limitation creates an inability to test the entire potential genetic landscape possible between these two parents. We uncovered a significant effect of glucosinolates on growth once we accounted for allelic differences in growth QTLs. Therefore, other growth QTLs can mask the effects of defense upon growth. Investigating direct links across phenotypic hierarchies is fraught with difficulty; we identify issues complicating this analysis. PMID:23749847

Effect of Circuit Inductance on Ceramics Joining by Titanium Foil Explosion

NASA Astrophysics Data System (ADS)

Takada, Yoshihiro; Takaki, Koichi; Itagaki, Minoru; Mukaigawa, Seiji; Fujiwara, Tamiya; Ohshima, Shuzo; Takahashi, Ikuo; Kuwashima, Takayuki

This article describes the influences of circuit inductance on alumina (Al2O3) tile joining using explosive titanium foil. Several kAs pulse current was supplied from 8.28 µF storage capacitor to the 50 µm thickness titanium foil which was sandwiched between the Al2O3 tiles with pressure of 8.3 MPa. The temperature of the foil was rapidly increased owing to ohmic heating with the large current, and then the foil was liquefied and vaporized. The Al2O3 tiles were successfully bonded when the input energy to the titanium foil was higher than the energy required for the foil vaporization. The bonding strength increases with increasing the energy input to the foil. However, the foil explosion cracked the tiles when the input energy exceeds a critical value. Increasing the circuit inductance from 1.13 µH to 64.8 µH, the critical energy of tile cracking increase from 160 J to 507 J, respectively. the maximum bonding strength of 330 kg was obtained when the circuit inductance was 21.8 µH. An investigation of the interfacial structure of the joints using electron probe micro-analysis revealed that distinct reaction areas existed in the interlayer.

Energy Consumption of Battery-Operated Screwdriver at Assembling Fixed Threaded Joints / Akumulatora Skrūvgrieža Elektroenerģijas Patēriņa Aprēķins, Veicot Nekustīga Vītņu Savienojuma Salikšanu Atkarībā No Operatora Reakcijas Laika

NASA Astrophysics Data System (ADS)

Grinevich, I.; Mozga, N.; Rudzitis, J.

2013-10-01

The electrical energy consumption of battery-operated screwdrivers, which are widely used in many industries, e.g. automotive, heavy, chemical, etc., can be considerably reduced. This would allow increasing the service life of a battery and reducing the time of its charging, thus increasing the productivity and decreasing the prime cost of this battery. It is shown that up to 17.9% of electrical energy could be saved at assembling fixed threaded joints by removing power from the screwdriver immediately after reaching the required tightening torque. Dotajā rakstā uzmanība tiek pievērsta akumulatora skrūvgrieža elektroenerģijas patēriņa samazināšanas iespējām sakarā ar problēmas aktualitāti šīs grupas plaši pielietotajiem instrumentiem. Elektroenerģijas patēriņa samazināšana masveida ražošanā, kur tiek izmantoti akumulatora skrūvgrieži, ļautu paildzināt akumulatora baterijas kalpošanas mūžu un samazināt uzlādēšanas laiku, kas, savukārt, novestu pie ražības palielināšanas un produkcijas pašizmaksas samazināšanas.

Synthesis, characterization and non-isothermal decomposition kinetic of a new galactochloralose based polymer.

PubMed

Kök, Gökhan; Ay, Kadir; Ay, Emriye; Doğan, Fatih; Kaya, Ismet

2014-01-30

A glycopolymer, poly(3-O-methacroyl-5,6-O-isopropylidene-1,2-O-(S)-trichloroethylidene-α-d-galactofuranose) (PMIPTEG) was synthesized from the sugar-carrying methacrylate monomer, 3-O-methacroyl-5,6-O-isopropylidene-1,2-O-(S)-trichloroethylidene-α-d-galactofuranose (MIPTEG) via conventional free radical polymerization with AIBN in 1,4-dioxane. The structures of glycomonomer and their polymers were confirmed by UV-vis, FT-IR, (1)H NMR, (13)C NMR, GPC, TG/DTG-DTA, DSC, and SEM techniques. SEM images showed that PMIPTEG had a straight-chain length structure. On the other hand, the thermal decomposition kinetics of polymer were investigated by means of thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. The apparent activation energies for thermal decomposition of the PMIPTEG were calculated using the Kissinger, Kim-Park, Tang, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman methods and were found to be 100.15, 104.40, 102.0, 102.2, 103.2 and 99.6 kJ/mol, respectively. The most likely process mechanism related to the thermal decomposition stage of PMIPTEG was determined to be a Dn deceleration type in terms of master plots results. Copyright © 2013 Elsevier Ltd. All rights reserved.

Kinetics of thermal decomposition of some biomasses in an inert environment. An investigation of the effect of lead loaded by biosorption.

PubMed

Martín-Lara, María Ángeles; Iáñez-Rodríguez, Irene; Blázquez, Gabriel; Quesada, Lucía; Pérez, Antonio; Calero, Mónica

2017-12-01

The thermal behavior of some types of raw and lead-polluted biomasses typical in south Spain was studied by non-isothermal thermogravimetry. Experiments were carried out in nitrogen atmosphere at three heating rates (5, 10 and 20°C/min). The results of thermogravimetric tests carried out proved that the presence of lead did not change the main degradation pathways of selected biomass (almond shell (AS) and olive pomace (OP)). However, from a point of view of mass loss, lead-polluted samples showed higher decomposition temperatures and decomposition at higher rate. The determination of activation energies was performed by isoconversional methods of Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman (FR). In general, lead-polluted samples showed lower activation energies than raw ones. Then, Coast-Redfern method was applied to determine kinetic function. The kinetic function that seems to determine the mechanism of thermal degradation of main components of all samples was nth order reaction. Finally, a model based on three parallel reactions (for three pseudocomponents) that fit to nth order reactions was evaluated. This model was appropriate to predict the pyrolysis behavior of the raw and lead-polluted samples in all pyrolysis conditions studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Studies of the Pyrolytic and Kinetic Characteristics of Maize Straw and the Seaweed Ulva pertusa

PubMed Central

Ye, Naihao; Li, Demao; Chen, Limei; Zhang, Xiaowen; Xu, Dong

2010-01-01

Seaweed has attracted considerable attention as a potential biofuel feedstock. The pyrolytic and kinetic characteristics of maize straw and the seaweed Ulva pertusa were studied and compared using heating rates of 10, 30 and 50°C min−1 under an inert atmosphere. The activation energy, and pre-exponential factors were calculated by the Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Popescu methods. The kinetic mechanism was deduced by the Popescu method. The results indicate that there are three stages to the pyrolysis; dehydration, primary devolatilization and residual decomposition. There were significant differences in average activation energy, thermal stability, final residuals and reaction rates between the two materials. The primary devolatilization stage of U. pertusa can be described by the Avramic-Erofeev equation (n = 3), whereas that of maize straw can be described by the Mampel Power Law (n = 2). The average activation energy of maize straw and U. pertusa were 153.0 and 148.7 KJ mol−1, respectively. The pyrolysis process of U.pertusa would be easier than maize straw. And co-firing of the two biomass may be require less external heat input and improve process stability. There were minor kinetic compensation effects between the pre-exponential factors and the activation energy. PMID:20844751

Cutaneous toxicities associated with vemurafenib therapy in 107 patients with BRAF V600E mutation-positive metastatic melanoma, including recognition and management of rare presentations.

PubMed

Sinha, R; Larkin, J; Gore, M; Fearfield, L

2015-10-01

Vemurafenib significantly improved overall survival compared with dacarbazine in patients with metastatic or unresectable BRAF V600E-positive melanoma in the BRIM-3 trial. However, vemurafenib was associated with a number of skin-related adverse events (AEs). To investigate the incidence and management of vemurafenib-associated skin AEs. This retrospective, observational study included adult patients with stage IIIC or IV melanoma who received vemurafenib between March 2010 and August 2013. Patients received oral vemurafenib 960 mg twice daily, with dose interruptions and reductions allowed for AE management. In total 107 patients were treated with vemurafenib during the study period. The most frequent clinically important skin-related AEs were rash (64%), squamoproliferative growths (41%), photosensitivity (40%) and squamous cell carcinoma (SCC) or keratoacanthoma (KA; 20%). Rare cases of granulomatous dermatitis and cutaneous T-cell lymphoma were also found. Rash was manageable with corticosteroids and dose modifications; squamoproliferative growths and SCCs/KAs were treated with cryotherapy and surgical excision, respectively. Patients were counselled regarding phototoxicity. The uncontrolled nature and retrospective design of the study, and the small patient numbers are limitations. Vemurafenib appears to have a predictable and manageable AE profile. Proactive management can limit the impact of AEs on patients, allowing treatment to continue despite toxicities. © 2015 British Association of Dermatologists.

Proteome Analysis of the Plasma Membrane of Mycobacterium Tuberculosis

PubMed Central

Arora, Shalini; Kosalai, K.; Namane, Abdelkader; Pym, Alex S.; Cole, Stewart T.

2002-01-01

The plasma membrane of Mycobacterium tuberculosis is likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane of M. tuberculosis H37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D-GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing the M. tuberculosis genome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI–MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to the M. tuberculosis proteome database. We classified 19 of the identified proteins as ‘membrane-associated’; 14 of these were further classified as ‘membrane-bound’, three of which were lipoproteins. The remaining proteins included four heat-shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting ‘putative’ M. tuberculosis membrane proteins. The protocol was also found to be suitable for comparing BCG and M. tuberculosis membranes, identifying ESAT-6 as being expressed selectively in M. tuberculosis. While this study demonstrates for the first time some of the membrane proteins of M. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium. PMID:18629250

Induction of virulence gene expression in Staphylococcus aureus by pulmonary surfactant.

PubMed

Ishii, Kenichi; Adachi, Tatsuo; Yasukawa, Jyunichiro; Suzuki, Yutaka; Hamamoto, Hiroshi; Sekimizu, Kazuhisa

2014-04-01

We performed a genomewide analysis using a next-generation sequencer to investigate the effect of pulmonary surfactant on gene expression in Staphylococcus aureus, a clinically important opportunistic pathogen. RNA sequence (RNA-seq) analysis of bacterial transcripts at late log phase revealed 142 genes that were upregulated >2-fold following the addition of pulmonary surfactant to the culture medium. Among these genes, we confirmed by quantitative reverse transcription-PCR analysis that mRNA amounts for genes encoding ESAT-6 secretion system C (EssC), an unknown hypothetical protein (NWMN_0246; also called pulmonary surfactant-inducible factor A [PsiA] in this study), and hemolysin gamma subunit B (HlgB) were increased 3- to 10-fold by the surfactant treatment. Among the major constituents of pulmonary surfactant, i.e., phospholipids and palmitate, only palmitate, which is the most abundant fatty acid in the pulmonary surfactant and a known antibacterial substance, stimulated the expression of these three genes. Moreover, these genes were also induced by supplementing the culture with detergents. The induction of gene expression by surfactant or palmitate was not observed in a disruption mutant of the sigB gene, which encodes an alternative sigma factor involved in bacterial stress responses. Furthermore, each disruption mutant of the essC, psiA, and hlgB genes showed attenuation of both survival in the lung and host-killing ability in a murine pneumonia model. These findings suggest that S. aureus resists membrane stress caused by free fatty acids present in the pulmonary surfactant through the regulation of virulence gene expression, which contributes to its pathogenesis within the lungs of the host animal.

Induction of Virulence Gene Expression in Staphylococcus aureus by Pulmonary Surfactant

PubMed Central

Ishii, Kenichi; Adachi, Tatsuo; Yasukawa, Jyunichiro; Suzuki, Yutaka; Hamamoto, Hiroshi

2014-01-01

We performed a genomewide analysis using a next-generation sequencer to investigate the effect of pulmonary surfactant on gene expression in Staphylococcus aureus, a clinically important opportunistic pathogen. RNA sequence (RNA-seq) analysis of bacterial transcripts at late log phase revealed 142 genes that were upregulated >2-fold following the addition of pulmonary surfactant to the culture medium. Among these genes, we confirmed by quantitative reverse transcription-PCR analysis that mRNA amounts for genes encoding ESAT-6 secretion system C (EssC), an unknown hypothetical protein (NWMN_0246; also called pulmonary surfactant-inducible factor A [PsiA] in this study), and hemolysin gamma subunit B (HlgB) were increased 3- to 10-fold by the surfactant treatment. Among the major constituents of pulmonary surfactant, i.e., phospholipids and palmitate, only palmitate, which is the most abundant fatty acid in the pulmonary surfactant and a known antibacterial substance, stimulated the expression of these three genes. Moreover, these genes were also induced by supplementing the culture with detergents. The induction of gene expression by surfactant or palmitate was not observed in a disruption mutant of the sigB gene, which encodes an alternative sigma factor involved in bacterial stress responses. Furthermore, each disruption mutant of the essC, psiA, and hlgB genes showed attenuation of both survival in the lung and host-killing ability in a murine pneumonia model. These findings suggest that S. aureus resists membrane stress caused by free fatty acids present in the pulmonary surfactant through the regulation of virulence gene expression, which contributes to its pathogenesis within the lungs of the host animal. PMID:24452679

CD8+ T Cells Provide an Immunologic Signature of Tuberculosis in Young Children

PubMed Central

Nyendak, Melissa; Kiguli, Sarah; Zalwango, Sarah; Mori, Tomi; Mayanja-Kizza, Harriet; Balyejusa, Stephen; Null, Megan; Baseke, Joy; Mulindwa, Deo; Byrd, Laura; Swarbrick, Gwendolyn; Scott, Christine; Johnson, Denise F.; Malone, LaShaunda; Mudido-Musoke, Philipa; Boom, W. Henry; Lewinsohn, David M.; Lewinsohn, Deborah A.

2012-01-01

Rationale: The immunologic events surrounding primary Mycobacterium tuberculosis infection and development of tuberculosis remain controversial. Young children who develop tuberculosis do so quickly after first exposure, thus permitting study of immune response to primary infection and disease. We hypothesized that M. tuberculosis–specific CD8+ T cells are generated in response to high bacillary loads occurring during tuberculosis. Objectives: To determine if M. tuberculosis–specific T cells are generated among healthy children exposed to M. tuberculosis and children with tuberculosis. Methods: Enzyme-linked immunosorbent spot assays were used to measure IFN-γ production in response to M. tuberculosis–specific proteins ESAT-6/CFP-10 by peripheral blood mononuclear cells and CD8+ T cells isolated from Ugandan children hospitalized with tuberculosis (n = 96) or healthy tuberculosis contacts (n = 62). Measurements and Main Results: The proportion of positive CD8+ T-cell assays and magnitude of CD8+ T-cell responses were significantly greater among young (<5 yr) tuberculosis cases compared with young contacts (P = 0.02, Fisher exact test, P = 0.01, Wilcoxon rank-sum, respectively). M. tuberculosis–specific T-cell responses measured in peripheral blood mononuclear cells were equivalent between groups. Conclusions: Among young children, M. tuberculosis–specific CD8+ T cells develop in response to high bacillary loads, as occurs during tuberculosis, and are unlikely to be found after M. tuberculosis exposure. T-cell responses measured in peripheral blood mononuclear cells are generated after M. tuberculosis exposure alone, and thus cannot distinguish exposure from disease. In young children, IFN-γ–producing M. tuberculosis–specific CD8+ T cells provide an immunologic signature of primary M. tuberculosis infection resulting in disease. PMID:22071329

The Secreted Protein Rv1860 of Mycobacterium tuberculosis Stimulates Human Polyfunctional CD8+ T Cells

PubMed Central

Kumar, Naveen; Biswas, Sunetra; Jumani, Rajiv S.; Jain, Chandni; Rani, Rajni; Aggarwal, Bharti; Singh, Jaya; Kotnur, Mohan Rao; Sridharan, Anand

2016-01-01

We previously reported that Rv1860 protein from Mycobacterium tuberculosis stimulated CD4+ and CD8+ T cells secreting gamma interferon (IFN-γ) in healthy purified protein derivative (PPD)-positive individuals and protected guinea pigs immunized with a DNA vaccine and a recombinant poxvirus expressing Rv1860 from a challenge with virulent M. tuberculosis. We now show Rv1860-specific polyfunctional T (PFT) cell responses in the blood of healthy latently M. tuberculosis-infected individuals dominated by CD8+ T cells, using a panel of 32 overlapping peptides spanning the length of Rv1860. Multiple subsets of CD8+ PFT cells were significantly more numerous in healthy latently infected volunteers (HV) than in tuberculosis (TB) patients (PAT). The responses of peripheral blood mononuclear cells (PBMC) from PAT to the peptides of Rv1860 were dominated by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) secretions, the former coming predominantly from non-T cell sources. Notably, the pattern of the T cell response to Rv1860 was distinctly different from those of the widely studied M. tuberculosis antigens ESAT-6, CFP-10, Ag85A, and Ag85B, which elicited CD4+ T cell-dominated responses as previously reported in other cohorts. We further identified a peptide spanning amino acids 21 to 39 of the Rv1860 protein with the potential to distinguish latent TB infection from disease due to its ability to stimulate differential cytokine signatures in HV and PAT. We suggest that a TB vaccine carrying these and other CD8+ T-cell-stimulating antigens has the potential to prevent progression of latent M. tuberculosis infection to TB disease. PMID:26843486

Designing CAF-adjuvanted dry powder vaccines: spray drying preserves the adjuvant activity of CAF01.

PubMed

Ingvarsson, Pall Thor; Schmidt, Signe Tandrup; Christensen, Dennis; Larsen, Niels Bent; Hinrichs, Wouter Leonardus Joseph; Andersen, Peter; Rantanen, Jukka; Nielsen, Hanne Mørck; Yang, Mingshi; Foged, Camilla

2013-05-10

Dry powder vaccine formulations are highly attractive due to improved storage stability and the possibility for particle engineering, as compared to liquid formulations. However, a prerequisite for formulating vaccines into dry formulations is that their physicochemical and adjuvant properties remain unchanged upon rehydration. Thus, we have identified and optimized the parameters of importance for the design of a spray dried powder formulation of the cationic liposomal adjuvant formulation 01 (CAF01) composed of dimethyldioctadecylammonium (DDA) bromide and trehalose 6,6'-dibehenate (TDB) via spray drying. The optimal excipient to stabilize CAF01 during spray drying and for the design of nanocomposite microparticles was identified among mannitol, lactose and trehalose. Trehalose and lactose were promising stabilizers with respect to preserving liposome size, as compared to mannitol. Trehalose and lactose were in the glassy state upon co-spray drying with the liposomes, whereas mannitol appeared crystalline, suggesting that the ability of the stabilizer to form a glassy matrix around the liposomes is one of the prerequisites for stabilization. Systematic studies on the effect of process parameters suggested that a fast drying rate is essential to avoid phase separation and lipid accumulation at the surface of the microparticles during spray drying. Finally, immunization studies in mice with CAF01 in combination with the tuberculosis antigen Ag85B-ESAT6-Rv2660c (H56) demonstrated that spray drying of CAF01 with trehalose under optimal processing conditions resulted in the preservation of the adjuvant activity in vivo. These data demonstrate the importance of liposome stabilization via optimization of formulation and processing conditions in the engineering of dry powder liposome formulations. Copyright © 2013 Elsevier B.V. All rights reserved.

CXCR6 is a marker for protective antigen-specific cells in the lungs after intranasal immunization against Mycobacterium tuberculosis.

PubMed

Lee, Lian Ni; Ronan, Edward O; de Lara, Catherine; Franken, Kees L M C; Ottenhoff, Tom H M; Tchilian, Elma Z; Beverley, Peter C L

2011-08-01

Convincing correlates of protective immunity against tuberculosis have been elusive. In BALB/c mice, intranasal immunization with a replication-deficient recombinant adenovirus expressing Mycobacterium tuberculosis antigen 85A (adenovirus-85A) induces protective lower respiratory tract immunity against pulmonary challenge with Mycobacterium tuberculosis, while intradermal immunization with adenovirus-85A does not. Here we report that intranasal immunization with adenovirus-85A induces expression of the chemokine receptor CXCR6 on lung CD8 T lymphocytes, which is maintained for at least 3 months. CXCR6-positive antigen-specific T cell numbers are increased among bronchoalveolar lavage-recoverable cells. Similarly, intranasal immunization with recombinant antigen 85A with adjuvant induces CXCR6 expression on lung CD4 cells in BALB/c and C57BL/6 mice, while a synthetic ESAT6(1-20) peptide with adjuvant induces CXCR6 expression in C57BL/6 mice. Parenteral immunization fails to do so. Upregulation of CXCR6 is accompanied by a transient elevation of serum CXCL16 after intranasal immunization, and lung cells cultured ex vivo from mice immunized intranasally show increased production of CXCL16. Administration of CXCL16 and cognate antigen intranasally to mice previously immunized parenterally increases the number of antigen-specific T lymphocytes in the bronchoalveolar lavage-recoverable population, which mediates inhibition of the early growth of Mycobacterium tuberculosis after challenge. We conclude that expression of CXCR6 on lung T lymphocytes is a correlate of local protective immunity against Mycobacterium tuberculosis after intranasal immunization and that CXCR6 and CXCL16 play an important role in the localization of T cells within lung tissue and the bronchoalveolar lavage-recoverable compartment.

CXCR6 Is a Marker for Protective Antigen-Specific Cells in the Lungs after Intranasal Immunization against Mycobacterium tuberculosis▿

PubMed Central

Lee, Lian Ni; Ronan, Edward O.; de Lara, Catherine; Franken, Kees L. M. C.; Ottenhoff, Tom H. M.; Tchilian, Elma Z.; Beverley, Peter C. L.

2011-01-01

Convincing correlates of protective immunity against tuberculosis have been elusive. In BALB/c mice, intranasal immunization with a replication-deficient recombinant adenovirus expressing Mycobacterium tuberculosis antigen 85A (adenovirus-85A) induces protective lower respiratory tract immunity against pulmonary challenge with Mycobacterium tuberculosis, while intradermal immunization with adenovirus-85A does not. Here we report that intranasal immunization with adenovirus-85A induces expression of the chemokine receptor CXCR6 on lung CD8 T lymphocytes, which is maintained for at least 3 months. CXCR6-positive antigen-specific T cell numbers are increased among bronchoalveolar lavage-recoverable cells. Similarly, intranasal immunization with recombinant antigen 85A with adjuvant induces CXCR6 expression on lung CD4 cells in BALB/c and C57BL/6 mice, while a synthetic ESAT61–20 peptide with adjuvant induces CXCR6 expression in C57BL/6 mice. Parenteral immunization fails to do so. Upregulation of CXCR6 is accompanied by a transient elevation of serum CXCL16 after intranasal immunization, and lung cells cultured ex vivo from mice immunized intranasally show increased production of CXCL16. Administration of CXCL16 and cognate antigen intranasally to mice previously immunized parenterally increases the number of antigen-specific T lymphocytes in the bronchoalveolar lavage-recoverable population, which mediates inhibition of the early growth of Mycobacterium tuberculosis after challenge. We conclude that expression of CXCR6 on lung T lymphocytes is a correlate of local protective immunity against Mycobacterium tuberculosis after intranasal immunization and that CXCR6 and CXCL16 play an important role in the localization of T cells within lung tissue and the bronchoalveolar lavage-recoverable compartment. PMID:21628524

Induction of a specific strong polyantigenic cellular immune response after short-term chemotherapy controls bacillary reactivation in murine and guinea pig experimental models of tuberculosis.

PubMed

Guirado, Evelyn; Gil, Olga; Cáceres, Neus; Singh, Mahavir; Vilaplana, Cristina; Cardona, Pere-Joan

2008-08-01

RUTI is a therapeutic vaccine that is generated from detoxified and liposomed Mycobacterium tuberculosis cell fragments that has demonstrated its efficacy in the control of bacillus reactivation after short-term chemotherapy. The aim of this study was to characterize the cellular immune response generated after the therapeutic administration of RUTI and to corroborate the lack of toxicity of the vaccine. Mouse and guinea pig experimental models were infected with a low-dose M. tuberculosis aerosol. RUTI-treated animals showed the lowest bacillary load in both experimental models. RUTI also decreased the percentage of pulmonary granulomatous infiltration in the mouse and guinea pig models. This was not the case after Mycobacterium bovis BCG treatment. Cellular immunity was studied through the characterization of the intracellular gamma interferon (IFN-gamma)-producing cells after the splenocytes' stimulation with M. tuberculosis-specific structural and growth-related antigens. Our data show that the difference between the therapeutic administration of BCG and RUTI resides mainly in the stronger activation of IFN-gamma(+) CD4(+) cells and CD8(+) cells against tuberculin purified protein derivative, ESAT-6, and Ag85B that RUTI generates. Both vaccines also triggered a specific immune response against the M. tuberculosis structural antigens Ag16kDa and Ag38kDa and a marked mRNA expression of IFN-gamma, tumor necrosis factor, interleukin-12, inducible nitric oxide synthase, and RANTES in the lung. The results show that RUTI's therapeutic effect is linked not only to the induction of a Th1 response but also to the stimulation of a quicker and stronger specific immunity against structural and growth-related antigens that reduces both the bacillary load and the pulmonary pathology.

Mycobacterium tuberculosis impairs dendritic cell functions through the serine hydrolase Hip1

PubMed Central

Madan-Lala, Ranjna; Sia, Jonathan Kevin; King, Rebecca; Adekambi, Toidi; Monin, Leticia; Khader, Shabaana A; Pulendran, Bali; Rengarajan, Jyothi

2014-01-01

Mycobacterium tuberculosis (Mtb) is a highly successful human pathogen that primarily resides in host phagocytes, such as macrophages and dendritic cells (DCs), and interferes with their functions. While multiple strategies used by Mtb to modulate macrophage responses have been discovered, interactions between Mtb and DCs are less well understood. DCs are the primary antigen presenting acells (APCs) of the immune system and play a central role in linking innate and adaptive immune responses to microbial pathogens. In this study we show that Mtb impairs DC cytokine secretion, maturation and antigen presentation through the cell envelope-associated serine hydrolase Hip1. Compared to wild type, a hip1 mutant strain of Mtb induced enhanced levels of the key T helper 1 (Th1)-inducing cytokine IL-12, as well as other proinflammatory cytokines (IL-23, IL-6, TNF-α, IL-1β, IL-18) in DCs via MyD88- and TLR2/9-dependent pathways, indicating that Hip1 restricts optimal DC inflammatory responses. Infection with the hip1 mutant also induced higher levels of MHC class II and co-stimulatory molecules, CD40 and CD86, indicating that Mtb impairs DC maturation through Hip1. Further, we show that Mtb promotes sub-optimal antigen presentation, as DCs infected with the hip1 mutant showed increased capacity to present antigen to OT-II- and early secreted antigenic target 6 (ESAT-6)-specific transgenic CD4 T cells and enhanced Th1 and Th17 polarization. Overall, these data show that Mtb impairs DC functions and modulates the nature of antigen-specific T cell responses, with important implications for vaccination strategies. PMID:24659689

Diagnostic usefulness of the QuantiFERON-TB gold in-tube test (QFT-GIT) for tuberculous vertebral osteomyelitis.

PubMed

Choi, Sungim; Jung, Kyung Hwa; Son, Hyo-Ju; Lee, Seung Hyun; Hong, Jung Min; Kim, Min Chul; Kim, Min Jae; Chong, Yong Pil; Sung, Heungsup; Lee, Sang-Oh; Choi, Sang-Ho; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

2018-05-01

Interferon (IFN)-γ-releasing assay for diagnosing tuberculosis (TB) has shown promise; however, there are only a few reports on usefulness of the QuantiFERON-TB Gold In-Tube test (QFT-GIT) for diagnosing TB vertebral osteomyelitis. All patients presenting at a tertiary hospital between January 2010 and July 2016 with suspected TB vertebral osteomyelitis were retrospectively enrolled to evaluate the diagnostic performance of QFT-GIT. We used QFT-GIT to measure the IFN-γ response to ESAT-6, CFP-10 and TB7.7. A total of 141 patients were enrolled; 32 (23%) were categorized as having confirmed TB, (1%) as probable TB, 14 (10%) as possible TB and 93 (66%) as not TB. Of these, 16 patients with probable and possible TB were excluded from the final analysis. Chronic granulomas with/without necrosis, acid-fast bacilli stain, M. tuberculosis polymerase chain reaction and cultures for M. tuberculosis were positive in 14 (44%), 12 (38%), 22 (69%) and 28 (88%) patients, respectively, among the 32 patients with confirmed TB. The overall sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for a positive result, and likelihood ratio for a negative result of the QFT-GIT for TB vertebral osteomyelitis were 91% (95% confidence interval [CI], 75-98%), 65% (95% CI, 54-75%), 50% (95% CI, 42-58%), 95% (95% CI, 86-98%), 2.59 (95% CI, 1.89-3.55) and 0.14 (95% CI, 0.05-0.43), respectively. The QFT-GIT appears to be a useful adjunct test for diagnosing TB vertebral osteomyelitis because the negative test results may be useful for excluding a diagnosis of active TB vertebral osteomyelitis.

Assessment of Wind Shear and Wind Energy Potential in the Baltic Sea Region of Latvia

NASA Astrophysics Data System (ADS)

Bezrukovs, V.; Bezrukovs, Vl.; Zacepins, A.; Komashilovs, V.

2015-04-01

The paper is devoted to the investigation into the wind energy potential based on long-term observations of the wind speed and energy density fluctuations at heights from 10 to 160 m on the Baltic Sea coast of Latvia. During the observations (2004 - 2013), the wind speed and direction values were measured, and the statistical database was accumulated using a LOGGER 9200 Symphonie measuring systems mounted on 60 m masts - one on the western coast and another on the north-east of Latvia. From June 2011 to May 2012, these measurements were complemented with the data for the heights from 40 to 160 m obtained by means of a ZephIR lidar and with the metrological data provided by "Latvian Environment, Geology and Meteorology Centre" for the same period. The graphs of seasonal fluctuations in the wind speed were obtained for the heights up to 160 m by measurements over the period of 2007 - 2013. The results of the research on the wind speed distribution up to 200 m are promising for evaluation of the wind energy potential of Latvia and will be helpful in assessment of prospective sites for construction of WPPs. Zinātniskais raksts ir veltīts pētījumam par vēja enerģijas potenciālu Latvijas teritorijā, Baltijas jūras piekrastē, balstoties uz ilgtermiņa vēja ātruma un vēja enerģijas blīvuma svārstību novērojumiem no 10 līdz 160 metriem augstumā. Vēja ātruma un vēja virziena mērījumu dati tika iegūti un apkopoti statistiskajā datubāzē laika periodā no 2004 līdz 2013. gadam, izmantojot mērīšanas sistēmu LOGGER 9200 Symphonie, kas bija ierīkotā uz 60 metru augsta masta - viena rietumu piekrastē un otra Latvijas ziemeļu-austrumos. No 2011. gada jūnija līdz 2012. gada maijam mērījumu datubāze tika papildināta ar datiem, kas tika iegūti ar lidaruZephIR augstumos no 40 līdz 160 metriem, un datiem no "Latvijas Vides, ģeoloģijas un meteoroloģijas centra" tam pašam laika periodam. Analizējot mērījumus 2007. g.-2013. g., grafiki ar

Genome scale transcriptional response diversity among ten ecotypes of Arabidopsis thaliana during heat stress

PubMed Central

Barah, Pankaj; Jayavelu, Naresh D.; Mundy, John; Bones, Atle M.

2013-01-01

In the scenario of global warming and climate change, heat stress is a serious threat to crop production worldwide. Being sessile, plants cannot escape from heat. Plants have developed various adaptive mechanisms to survive heat stress. Several studies have focused on diversity of heat tolerance levels in divergent Arabidopsis thaliana (A. thaliana) ecotypes, but comprehensive genome scale understanding of heat stress response in plants is still lacking. Here we report the genome scale transcript responses to heat stress of 10 A. thaliana ecotypes (Col, Ler, C24, Cvi, Kas1, An1, Sha, Kyo2, Eri, and Kond) originated from different geographical locations. During the experiment, A. thaliana plants were subjected to heat stress (38°C) and transcript responses were monitored using Arabidopsis NimbleGen ATH6 microarrays. The responses of A. thaliana ecotypes exhibited considerable variation in the transcript abundance levels. In total, 3644 transcripts were significantly heat regulated (p < 0.01) in the 10 ecotypes, including 244 transcription factors and 203 transposable elements. By employing a systems genetics approach- Network Component Analysis (NCA), we have constructed an in silico transcript regulatory network model for 35 heat responsive transcription factors during cellular responses to heat stress in A. thaliana. The computed activities of the 35 transcription factors showed ecotype specific responses to the heat treatment. PMID:24409190

Effect of Bronsted Acids and Bases, and Lewis Acid (Sn(2+)) on the Regiochemistry of the Reaction of Amines with Trifluoromethyl-β-diketones: Reaction of 3-Aminopyrrole to Selectively Produce Regioisomeric 1H-Pyrrolo[3,2-b]pyridines.

PubMed

De Rosa, Michael; Arnold, David; Hartline, Douglas; Truong, Linda; Verner, Roman; Wang, Tianwei; Westin, Christian

2015-12-18

Reaction of 3-aminopyrrole (as its salt) with trifluoromethyl-β-diketones gave γ-1H-pyrrolo[3,2-b]pyridines via reaction at the less reactive carbonyl group. The trifluoromethyl group increased the electrophilicity of the adjacent carbonyl group and decreased the basicity of the hydroxyl group of the CF3 amino alcohol formed. This amino alcohol was formed faster, but its subsequent dehydration to the β-enaminone was slow resulting in the preferential formation of the γ-regioisomer. Reaction of 4,4,4-trifluoro-1-phenyl-1,3-butadione with 3-aminopyrrole was carried out using a series of 6 amine buffers. Yields of the α-1H-pyrrolo[3,2-b]pyridine increased as the pKa of the amine buffer decreased. Surprisingly the yield went down at higher pKas. There was a change in mechanism as the reaction mixture became more basic. With strong amines trifluoromethyl-β-diketones were present mainly or completely as the enolate. Under reductive conditions (3-nitropyrrole/Sn/AcOH/trifluoromethyl-β-diketone) the α-1H-pyrrolo[3,2-b]pyridine was the major product as a result of Lewis acid catalysis by Sn(2+). Similar α-regiochemistry was observed when the reaction of the 3-aminopyrrole salt with trifluoromethyl-β-diketones was carried out in the presence of base and tin(II) acetate.

PHEPS: web-based pH-dependent Protein Electrostatics Server

PubMed Central

Kantardjiev, Alexander A.; Atanasov, Boris P.

2006-01-01

PHEPS (pH-dependent Protein Electrostatics Server) is a web service for fast prediction and experiment planning support, as well as for correlation and analysis of experimentally obtained results, reflecting charge-dependent phenomena in globular proteins. Its implementation is based on long-term experience (PHEI package) and the need to explain measured physicochemical characteristics at the level of protein atomic structure. The approach is semi-empirical and based on a mean field scheme for description and evaluation of global and local pH-dependent electrostatic properties: protein proton binding; ionic sites proton population; free energy electrostatic term; ionic groups proton affinities (pKa,i) and their Coulomb interaction with whole charge multipole; electrostatic potential of whole molecule at fixed pH and pH-dependent local electrostatic potentials at user-defined set of points. The speed of calculation is based on fast determination of distance-dependent pair charge-charge interactions as empirical three exponential function that covers charge–charge, charge–dipole and dipole–dipole contributions. After atomic coordinates input, all standard parameters are used as defaults to facilitate non-experienced users. Special attention was given to interactive addition of non-polypeptide charges, extra ionizable groups with intrinsic pKas or fixed ions. The output information is given as plain-text, readable by ‘RasMol’, ‘Origin’ and the like. The PHEPS server is accessible at . PMID:16845042

Expression Quantitative Trait Locus Mapping across Water Availability Environments Reveals Contrasting Associations with Genomic Features in Arabidopsis[C][W][OPEN

PubMed Central

Lowry, David B.; Logan, Tierney L.; Santuari, Luca; Hardtke, Christian S.; Richards, James H.; DeRose-Wilson, Leah J.; McKay, John K.; Sen, Saunak; Juenger, Thomas E.

2013-01-01

The regulation of gene expression is crucial for an organism’s development and response to stress, and an understanding of the evolution of gene expression is of fundamental importance to basic and applied biology. To improve this understanding, we conducted expression quantitative trait locus (eQTL) mapping in the Tsu-1 (Tsushima, Japan) × Kas-1 (Kashmir, India) recombinant inbred line population of Arabidopsis thaliana across soil drying treatments. We then used genome resequencing data to evaluate whether genomic features (promoter polymorphism, recombination rate, gene length, and gene density) are associated with genes responding to the environment (E) or with genes with genetic variation (G) in gene expression in the form of eQTLs. We identified thousands of genes that responded to soil drying and hundreds of main-effect eQTLs. However, we identified very few statistically significant eQTLs that interacted with the soil drying treatment (GxE eQTL). Analysis of genome resequencing data revealed associations of several genomic features with G and E genes. In general, E genes had lower promoter diversity and local recombination rates. By contrast, genes with eQTLs (G) had significantly greater promoter diversity and were located in genomic regions with higher recombination. These results suggest that genomic architecture may play an important a role in the evolution of gene expression. PMID:24045022

Exploiting Differential Gene Expression and Epistasis to Discover Candidate Genes for Drought-Associated QTLs in Arabidopsis thaliana.

PubMed

Lovell, John T; Mullen, Jack L; Lowry, David B; Awole, Kedija; Richards, James H; Sen, Saunak; Verslues, Paul E; Juenger, Thomas E; McKay, John K

2015-04-01

Soil water availability represents one of the most important selective agents for plants in nature and the single greatest abiotic determinant of agricultural productivity, yet the genetic bases of drought acclimation responses remain poorly understood. Here, we developed a systems-genetic approach to characterize quantitative trait loci (QTLs), physiological traits and genes that affect responses to soil moisture deficit in the TSUxKAS mapping population of Arabidopsis thaliana. To determine the effects of candidate genes underlying QTLs, we analyzed gene expression as a covariate within the QTL model in an effort to mechanistically link markers, RNA expression, and the phenotype. This strategy produced ranked lists of candidate genes for several drought-associated traits, including water use efficiency, growth, abscisic acid concentration (ABA), and proline concentration. As a proof of concept, we recovered known causal loci for several QTLs. For other traits, including ABA, we identified novel loci not previously associated with drought. Furthermore, we documented natural variation at two key steps in proline metabolism and demonstrated that the mitochondrial genome differentially affects genomic QTLs to influence proline accumulation. These findings demonstrate that linking genome, transcriptome, and phenotype data holds great promise to extend the utility of genetic mapping, even when QTL effects are modest or complex. © 2015 American Society of Plant Biologists. All rights reserved.

Enhanced astaxanthin production from Haematococcus pluvialis using butylated hydroxyanisole.

PubMed

Shang, Minmin; Ding, Wei; Zhao, Yongteng; Xu, Jun-Wei; Zhao, Peng; Li, Tao; Ma, Huixian; Yu, Xuya

2016-10-20

Haematococcus pluvialis is a promising natural source of high-value antioxidant astaxanthin under stress conditions. Biotic or abiotic elicitors are effective strategies for improving astaxanthin production in H. pluvialis. Butylated hydroxyanisole (BHA) was identified as an effective inducer for H. pluvialis LUGU. Under a treatment of 2mgL(-1) BHA (BHA2), astaxanthin content reached a maximum of 29.03mgg(-1) dry weight (DW) (2.03-fold of that in the control) after 12day of the mid-exponential growth phase. Subsequently, H. pluvialis LUGU was subjected to BHA2 at different growth phases because an appropriate time node for adding elicitors is vital for the entire production to succeed. As a result, the highest astaxanthin content (29.3mgg(-1) DW) was obtained in cells on day 14 (BHA2 14) of the late-exponential growth phase. Furthermore, the samples treated with BHA2 14 and the control group were compared in terms of the transcriptional expression of seven carotenogenesis genes, fatty acid composition, and total accumulated astaxanthin. All selected genes exhibited up-regulated expression profiles, with chy, crtO, and bkt exhibiting higher maximum transcriptional levels than the rest. Oleic acid content increased 33.15-fold, with acp, fad, and kas expression being enhanced on the day when astaxanthin was produced rapidly. Copyright © 2016 Elsevier B.V. All rights reserved.

Structure-Activity Relationships for Rates of Aromatic Amine Oxidation by Manganese Dioxide.

PubMed

Salter-Blanc, Alexandra J; Bylaska, Eric J; Lyon, Molly A; Ness, Stuart C; Tratnyek, Paul G

2016-05-17

New energetic compounds are designed to minimize their potential environmental impacts, which includes their transformation and the fate and effects of their transformation products. The nitro groups of energetic compounds are readily reduced to amines, and the resulting aromatic amines are subject to oxidation and coupling reactions. Manganese dioxide (MnO2) is a common environmental oxidant and model system for kinetic studies of aromatic amine oxidation. In this study, a training set of new and previously reported kinetic data for the oxidation of model and energetic-derived aromatic amines was assembled and subjected to correlation analysis against descriptor variables that ranged from general purpose [Hammett σ constants (σ(-)), pKas of the amines, and energies of the highest occupied molecular orbital (EHOMO)] to specific for the likely rate-limiting step [one-electron oxidation potentials (Eox)]. The selection of calculated descriptors (pKa, EHOMO, and Eox) was based on validation with experimental data. All of the correlations gave satisfactory quantitative structure-activity relationships (QSARs), but they improved with the specificity of the descriptor. The scope of correlation analysis was extended beyond MnO2 to include literature data on aromatic amine oxidation by other environmentally relevant oxidants (ozone, chlorine dioxide, and phosphate and carbonate radicals) by correlating relative rate constants (normalized to 4-chloroaniline) to EHOMO (calculated with a modest level of theory).

Solid State Physics. Nitrogen Adsorption by Thermoexfoliated Graphite / Slāpekļa Adsorbcija Uz Termoeksfoliētā Grafīta

NASA Astrophysics Data System (ADS)

Grehov, V.; Kalnacs, J.; Matzui, L.; Knite, M.; Murashov, A.; Vilken, A.

2013-02-01

Adsorption by thermochemically exfoliated graphite (TEG) is studied and compared with that by other carbon structures under the same conditions. In BET determination of the specific surface area (SBET) for the TEG samples it was found that good approximation could be observed in two different pressure ranges. Such ranges of BET approximation are also visible in the isotherms of aquadag and milled graphite. The experimental results are discussed and their interpretation proposed Ar sorbcijas iekārtu Autosorb-1 (Quantochrome Instruments Co, Florida, USA) pētīta termiski eksfoliēta grafīta slāpekļa sorbcijas spēja salīdzinājumā ar citu oglekļa struktūru sorbciju tādos pašos apstākļos. Atrasti divi izotermu rajoni, kas raksturojas ar mazu (SBET1) un palielinātu (SBET2) īpatnējo virsmu.. Šāda veida izotermas raksturīgas slikti adsorbējošiem materiāliem, pie kādiem pieder arī akvadags. Labi adsorbējošās oglekļa struktūrām, tādām kā aktīvā ogle un oglekļa nanocaurules, raksturīgas cita veida izotermas. Apspriesta eksperimentālā rezultāta interpretācija

COMPASS Final Report: Lunar Communications Terminal (LCT)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2010-01-01

The Lunar Communications Terminal (LCT) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session designed a terminal to provide communications between lunar South Pole assets, communications relay to/from these assets through an orbiting Lunar Relay Satellite (LRS) and navigation support. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The Terminal consists of a pallet containing the communications and avionics equipment, surrounded by the thermal control system (radiator), an attached, deployable 10-m tower, upon which were mounted locally broadcasting and receiving modems and a deployable 1 m diameter Ka/S band dish which provides relay communications with the lunar relay satellites and, as a backup, Earth when it is in view. All power was assumed to come from the lunar outpost Habitat. Three LCT design options were explored: a stand-alone LCT servicing the manned outpost, an integrated LCT (into the Habitat or Lunar Lander), and a mini-LCT which provides a reduced level of communication for primarily robotic areas dealing as in situ resource utilization (ISRU) and remote science. Where possible all the designs assumed single fault tolerance. Significant mass savings were found when integrating the LCT into the Habitat or Lander but increases in costs occurred depending upon the level of man rating required for such designs.

COMPASS Final Report: Lunar Relay Satellite (LRS)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2012-01-01

The Lunar Relay Satellite (LRS) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session was tasked to design a satellite to orbit in an elliptical lunar polar orbit to provide relay communications between lunar South Pole assets and the Earth. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The LRS is a half-TDRSS sized box spacecraft, which provides communications and navigation relay between lunar outposts (via Lunar Communications Terminals (LCT)) or Sortie parties (with user radios) and large ground antennas on Earth. The LRS consists of a spacecraft containing all the communications and avionics equipment designed by NASA Jet Propulsion Laboratory s (JPL) Team X to perform the relay between lunar-based assets and the Earth. The satellite design is a standard box truss spacecraft design with a thermal control system, 1.7 m solar arrays for 1 kWe power, a 1 m diameter Ka/S band dish which provides relay communications with the LCT, and a Q-band dish for communications to/from the Earth based assets. While JPL's Team X and Goddard Space Flight Center s (GSFC) I M Design Center (IMDC) have completed two other LRS designs, this NASA Glenn Research Center (GRC) COMPASS LRS design sits between them in terms of physical size and capabilities.

A role for NF-κB activity in skin hyperplasia and the development of keratoacanthomata in mice.

PubMed

Poligone, Brian; Hayden, Matthew S; Chen, Luojing; Pentland, Alice P; Jimi, Eijiro; Ghosh, Sankar

2013-01-01

Previous studies have implicated NF-κB signaling in both cutaneous development and oncogenesis. However, these studies have been limited in part by the lethality that results from extreme over- or under-expression of NF-κB in available mouse models. Even cre-driven tissue specific expression of transgenes, or targeted deletion of NF-κB can cause cell death. Therefore, the present study was undertaken to evaluate a novel mouse model of enhanced NF-κB activity in the skin. A knock-in homologous recombination technique was utilized to develop a mouse model (referred to as PD mice) with increased NF-κB activity. The data show that increased NF-κB activity leads to hyperproliferation and dysplasia of the mouse epidermis. Chemical carcinogenesis in the context of enhanced NF-κB activity promotes the development of keratoacanthomata. Our findings support an important role for NF-κB in keratinocyte dysplasia. We have found that enhanced NF-κB activity renders keratinocytes susceptible to hyperproliferation and keratoacanthoma (KA) development but is not sufficient for transformation and SCC development. We therefore propose that NF-κB activation in the absence of additional oncogenic events can promote TNF-dependent, actinic keratosis-like dysplasia and TNF-independent, KAs upon chemical carcinogensis. These studies suggest that resolution of KA cannot occur when NF-κB activation is constitutively enforced.

Role of Modulators in Controlling the Colloidal Stability and Polydispersity of the UiO-66 Metal–Organic Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morris, William; Wang, Shunzhi; Cho, David

2017-04-07

Nanoscale UiO-66 Zr6(OH)4O4(C8O4H4)6 has been synthesized with a series of carboxylic acid modulators, R-COOH (where R = H, CH3, CF3, and CHCl2). The phase purity and size of each MOF was confirmed by powder X-ray diffraction, BET surface area analysis, and scanning transmission electron microscopy (STEM). Size control of UiO-66 crystals from 20 nm to over 1 μm was achieved, and confirmed by STEM. The colloidal stability of each MOF was evaluated by dynamic light scattering and was found to be highly dependent on the modulator conditions utilized in the synthesis, with both lower pKa and higher acid concentration resultingmore » in more stable structures. Furthermore, STEM was carried out on both colloidally stable samples and those that exhibited a large degree of aggregation, which allowed for visualization of the different degrees of dispersion of the samples. The use of modulators at higher concentrations and with lower pKas leads to the formation of more defects, as a consequence of terephthalic acid ligands being replaced by modulator molecules, thereby enhancing the colloidal stability of the UiO-66 nanoparticles. These findings could have a significant impact on nanoscale MOF material syntheses and applications, especially in the areas of catalysis and drug delivery.« less

Immunogenic membrane-associated proteins of Mycobacterium tuberculosis revealed by proteomics.

PubMed

Sinha, Sudhir; Kosalai, K; Arora, Shalini; Namane, Abdelkader; Sharma, Pawan; Gaikwad, Anil N; Brodin, Priscille; Cole, Stewart T

2005-07-01

Membrane-associated proteins of Mycobacterium tuberculosis offer a challenge, as well as an opportunity, in the quest for better therapeutic and prophylactic interventions against tuberculosis. The authors have previously reported that extraction with the detergent Triton X-114 (TX-114) is a useful step in proteomic analysis of mycobacterial cell membranes, and detergent-soluble membrane proteins of mycobacteria are potent stimulators of human T cells. In this study 1-D and 2-D gel electrophoresis-based protocols were used for the analysis of proteins in the TX-114 extract of M. tuberculosis membranes. Peptide mass mapping (using MALDI-TOF-MS, matrix assisted laser desorption/ionization time of flight mass spectrometry) of 116 samples led to the identification of 105 proteins, 9 of which were new to the M. tuberculosis proteome. Functional orthologues of 73 of these proteins were also present in Mycobacterium leprae, suggesting their relative importance. Bioinformatics predicted that as many as 73% of the proteins had a hydrophobic disposition. 1-D gel electrophoresis revealed more hydrophobic/transmembrane and basic proteins than 2-D gel electrophoresis. Identified proteins fell into the following major categories: protein synthesis, cell wall biogenesis/architecture and conserved hypotheticals/unknowns. To identify immunodominant proteins of the detergent phase (DP), 14 low-molecular-mass fractions prepared by continuous-elution gel electrophoresis were subjected to T cell activation assays using blood samples from BCG-vaccinated healthy donors from a tuberculosis endemic area. Analysis of the responses (cell proliferation and IFN-gamma production) showed that the immunodominance of certain DP fractions was most probably due to ribosomal proteins, which is consistent with both their specificity for mycobacteria and their abundance. Other membrane-associated proteins, including transmembrane proteins/lipoproteins and ESAT-6, did not appear to contribute

Mycobacterium tuberculosis specific CD8(+) T cells rapidly decline with antituberculosis treatment.

PubMed

Nyendak, Melissa R; Park, Byung; Null, Megan D; Baseke, Joy; Swarbrick, Gwendolyn; Mayanja-Kizza, Harriet; Nsereko, Mary; Johnson, Denise F; Gitta, Phineas; Okwera, Alphonse; Goldberg, Stefan; Bozeman, Lorna; Johnson, John L; Boom, W Henry; Lewinsohn, Deborah A; Lewinsohn, David M

2013-01-01

Biomarkers associated with response to therapy in tuberculosis could have broad clinical utility. We postulated that the frequency of Mycobacterium tuberculosis (Mtb) specific CD8(+) T cells, by virtue of detecting intracellular infection, could be a surrogate marker of response to therapy and would decrease during effective antituberculosis treatment. We sought to determine the relationship of Mtb specific CD4(+) T cells and CD8(+) T cells with duration of antituberculosis treatment. We performed a prospective cohort study, enrolling between June 2008 and August 2010, of HIV-uninfected Ugandan adults (n = 50) with acid-fast bacillus smear-positive, culture confirmed pulmonary TB at the onset of antituberculosis treatment and the Mtb specific CD4(+) and CD8(+) T cell responses to ESAT-6 and CFP-10 were measured by IFN-γ ELISPOT at enrollment, week 8 and 24. There was a significant difference in the Mtb specific CD8(+) T response, but not the CD4(+) T cell response, over 24 weeks of antituberculosis treatment (p<0.0001), with an early difference observed at 8 weeks of therapy (p = 0.023). At 24 weeks, the estimated Mtb specific CD8(+) T cell response decreased by 58%. In contrast, there was no significant difference in the Mtb specific CD4(+) T cell during the treatment. The Mtb specific CD4(+) T cell response, but not the CD8(+) response, was negatively impacted by the body mass index. Our data provide evidence that the Mtb specific CD8(+) T cell response declines with antituberculosis treatment and could be a surrogate marker of response to therapy. Additional research is needed to determine if the Mtb specific CD8(+) T cell response can detect early treatment failure, relapse, or to predict disease progression.

Evaluation of a whole-blood chemiluminescent immunoassay of IFN-γ, IP-10, and MCP-1 for diagnosis of active pulmonary tuberculosis and tuberculous pleurisy patients.

PubMed

Liang, Yan; Wang, Ying; Li, Hang; Yang, Yourong; Liu, Jianyang; Yu, Ting; Wu, Xueqiong

2016-10-01

The study explored the use of IP-10, MCP-1, and IFN-γ as biomarkers to improve the diagnoses of active pulmonary tuberculosis and tuberculous pleurisy. We enrolled 267 individuals, including 134 TB patients, 93 patients with non-tuberculous pulmonary diseases, and 40 healthy controls. Whole bloods were stimulated in vitro with rCFP-10/ESAT-6 protein antigen of Mycobacterium tuberculosis. The levels of IFN-γ, IP-10, and MCP-1 in cultured supernatants of whole bloods were detected by a chemiluminescence immunoassay. A receiver operating characteristic (ROC) curve was drawn to determine the cutoff value for diagnosing TB and to evaluate the diagnostic efficacies of the IFN-γ, IP-10, and MCP-1 for TB. The antigen-specific release of each cytokine, IFN-γ, IP-10, and MCP-1, was significantly higher in the TB groups than in either the non-tuberculous pulmonary disease group (p < 0.001) or the healthy control group (p < 0.001). The ROC curves indicated cutoff values for IFN-γ, IP-10, and MCP-1 at 147.8, 160.4, and 496.4 pg/mL, respectively. The sensitivity, specificity, PPV, NPV, and diagnostic efficiency for IFN-γ were 85.8%, 70.7%, 74.7%, 83.2%, and 78.3%, respectively; for IP-10 were 72.4%, 75.9%, 75.2%, 73.2%, and 74.2%, respectively; and for MCP-1 were 90.3%, 97.0%, 96.8%, 90.8%, and 93.6%, respectively. IFN-γ combined MCP-1 improved the sensitivity to 97.8% compared with IFN-γ (p < 0.001). Our findings indicate high sensitivity and specificity of MCP-1 as novel biomarkers for the diagnosis of active pulmonary tuberculosis and tuberculous pleurisy. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Immuno Nanosensor for the Ultrasensitive Naked Eye Detection of Tuberculosis.

PubMed

Mohd Bakhori, Noremylia; Yusof, Nor Azah; Abdullah, Jaafar; Wasoh, Helmi; Md Noor, Siti Suraiya; Ahmad Raston, Nurul Hanun; Mohammad, Faruq

2018-06-14

In the present study, a beneficial approach for the ultrasensitive and affordable naked eye detection and diagnosis of tuberculosis (TB) by utilizing plasmonic enzyme-linked immunosorbent assay (ELISA) via antibody-antigen interaction was studied. Here, the biocatalytic cycle of the intracellular enzymes links to the formation and successive growth of the gold nanoparticles (GNPs) for ultrasensitive detection. The formation of different colored solutions by the plasmonic nanoparticles in the presence of enzyme labels links directly to the existence or non-existence of the TB analytes in the sample solutions. For disease detection, the adapted protocol is based mainly on the conventional ELISA procedure that involves catalase-labeled antibodies, i.e., the enzymes consume hydrogen peroxide and further produce GNPs with the addition of gold (III) chloride. The amount of hydrogen peroxide remaining in the solution determines whether the GNPs solution is to be formed in the color blue or the color red, as it serves as a confirmation for the naked eye detection of TB analytes. However, the conventional ELISA method only shows tonal colors that need a high concentration of analyte to achieve high confidence levels for naked eye detection. Also, in this research, we proposed the incorporation of protein biomarker, Mycobacterium tuberculosis ESAT-6-like protein esxB (CFP-10), as a means of TB detection using plasmonic ELISA. With the use of this technique, the CFP-10 detection limit can be lowered to 0.01 µg/mL by the naked eye. Further, our developed technique was successfully tested and confirmed with sputum samples from patients diagnosed with positive TB, thereby providing enough evidence for the utilization of our technique in the early diagnosis of TB disease.

Mycobacterium tuberculosis Specific CD8+ T Cells Rapidly Decline with Antituberculosis Treatment

PubMed Central

Nyendak, Melissa R.; Park, Byung; Null, Megan D.; Baseke, Joy; Swarbrick, Gwendolyn; Mayanja-Kizza, Harriet; Nsereko, Mary; Johnson, Denise F.; Gitta, Phineas; Okwera, Alphonse; Goldberg, Stefan; Bozeman, Lorna; Johnson, John L.; Boom, W. Henry; Lewinsohn, Deborah A.; Lewinsohn, David M.

2013-01-01

Rationale Biomarkers associated with response to therapy in tuberculosis could have broad clinical utility. We postulated that the frequency of Mycobacterium tuberculosis (Mtb) specific CD8+ T cells, by virtue of detecting intracellular infection, could be a surrogate marker of response to therapy and would decrease during effective antituberculosis treatment. Objectives: We sought to determine the relationship of Mtb specific CD4+ T cells and CD8+ T cells with duration of antituberculosis treatment. Materials and Methods We performed a prospective cohort study, enrolling between June 2008 and August 2010, of HIV-uninfected Ugandan adults (n = 50) with acid-fast bacillus smear-positive, culture confirmed pulmonary TB at the onset of antituberculosis treatment and the Mtb specific CD4+ and CD8+ T cell responses to ESAT-6 and CFP-10 were measured by IFN-γ ELISPOT at enrollment, week 8 and 24. Results There was a significant difference in the Mtb specific CD8+ T response, but not the CD4+ T cell response, over 24 weeks of antituberculosis treatment (p<0.0001), with an early difference observed at 8 weeks of therapy (p = 0.023). At 24 weeks, the estimated Mtb specific CD8+ T cell response decreased by 58%. In contrast, there was no significant difference in the Mtb specific CD4+ T cell during the treatment. The Mtb specific CD4+ T cell response, but not the CD8+ response, was negatively impacted by the body mass index. Conclusions Our data provide evidence that the Mtb specific CD8+ T cell response declines with antituberculosis treatment and could be a surrogate marker of response to therapy. Additional research is needed to determine if the Mtb specific CD8+ T cell response can detect early treatment failure, relapse, or to predict disease progression. PMID:24324704

Potential Immunological Biomarkers for Detection of Mycobacterium tuberculosis Infection in a Setting Where M. tuberculosis Is Endemic, Ethiopia.

PubMed

Teklu, Takele; Kwon, Keehwan; Wondale, Biniam; HaileMariam, Milkessa; Zewude, Aboma; Medhin, Girmay; Legesse, Mengistu; Pieper, Rembert; Ameni, Gobena

2018-04-01

Accurate diagnosis and early treatment of tuberculosis (TB) and latent TB infection (LTBI) are vital to prevent and control TB. The lack of specific biomarkers hinders these efforts. This study's purpose was to screen immunological markers that discriminate Mycobacterium tuberculosis infection outcomes in a setting where it is endemic, Ethiopia. Whole blood from 90 participants was stimulated using the ESAT-6/CFP-10 antigen cocktail. The interferon gamma (IFN-γ)-based QuantiFERON diagnostic test was used to distinguish between LTBI and uninfected control cases. Forty cytokines/chemokines were detected from antigen-stimulated plasma supernatants (SPSs) and unstimulated plasma samples (UPSs) using human cytokine/chemokine antibody microarrays. Statistical tests allowed us to identify potential biomarkers that distinguish the TB, LTBI, and healthy control groups. As expected, the levels of IFN-γ in SPSs returned a high area under the receiver operating characteristic curve (AUC) value comparing healthy controls and LTBI cases (Z = 0.911; P < 0.001). The SPS data also indicated that interleukin 17 (IL-17) abundance discriminates LTBI from healthy controls (Z = 0.763; P = 0.001). RANTES and MIP-1β were significantly elevated in SPSs of TB-infected compared to healthy controls ( P < 0.05), while IL-12p40 and soluble tumor necrosis factor receptor II (sTNF-RII) were significantly increased in active TB cases compared to the combined LTBI and control groups ( P < 0.05). Interestingly, quantitative changes for RANTES were observed using both SPSs and UPSs, with P values of 0.013 and 0.012, respectively, in active TB versus LTBI cases and 0.001 and 0.002, respectively, in active TB versus healthy controls. These results encourage biomarker verification studies for IL-17 and RANTES. Combinations of these cytokines may complement IFN-γ measurements to diagnose LTBI and distinguish active TB from LTBI cases. Copyright © 2018 American Society for Microbiology.

Designing and Developing a NASA Research Projects Knowledge Base and Implementing Knowledge Management and Discovery Techniques

NASA Astrophysics Data System (ADS)

Dabiru, L.; O'Hara, C. G.; Shaw, D.; Katragadda, S.; Anderson, D.; Kim, S.; Shrestha, B.; Aanstoos, J.; Frisbie, T.; Policelli, F.; Keblawi, N.

2006-12-01

The Research Project Knowledge Base (RPKB) is currently being designed and will be implemented in a manner that is fully compatible and interoperable with enterprise architecture tools developed to support NASA's Applied Sciences Program. Through user needs assessment, collaboration with Stennis Space Center, Goddard Space Flight Center, and NASA's DEVELOP Staff personnel insight to information needs for the RPKB were gathered from across NASA scientific communities of practice. To enable efficient, consistent, standard, structured, and managed data entry and research results compilation a prototype RPKB has been designed and fully integrated with the existing NASA Earth Science Systems Components database. The RPKB will compile research project and keyword information of relevance to the six major science focus areas, 12 national applications, and the Global Change Master Directory (GCMD). The RPKB will include information about projects awarded from NASA research solicitations, project investigator information, research publications, NASA data products employed, and model or decision support tools used or developed as well as new data product information. The RPKB will be developed in a multi-tier architecture that will include a SQL Server relational database backend, middleware, and front end client interfaces for data entry. The purpose of this project is to intelligently harvest the results of research sponsored by the NASA Applied Sciences Program and related research program results. We present various approaches for a wide spectrum of knowledge discovery of research results, publications, projects, etc. from the NASA Systems Components database and global information systems and show how this is implemented in SQL Server database. The application of knowledge discovery is useful for intelligent query answering and multiple-layered database construction. Using advanced EA tools such as the Earth Science Architecture Tool (ESAT), RPKB will enable NASA and

Heinrich events and sea level changes: records from uplifted coral terraces and marginal seas

NASA Astrophysics Data System (ADS)

Yokoyama, Y.; Esat, T. M.; Suga, H.; Obrochta, S.; Ohkouchi, N.

2017-12-01

Repeated major ice discharge events spaced every ca.7,000 years during the last ice age was first detected in deep sea sediments from North Atlantic. Characterized as lithic layers, these Heinrich Events (Heinrich, 1988 QR) correspond to rapid climate changes attributed to weakened ocean circulation (eg., Broecker, 1994 Nature; Alley, 1998 Nature) as shown by a number of different proxies. A better understanding of the overall picture of Heinrich events would benefit from determining the total amount of ice involved each event, which is still under debate. Sea level records are the most direct means for that, and uranium series dated corals can constrain the timing precisely. However, averaged global sea level during the time of interest was around -70m, hindering study from tectonically stable regions. Using uplifted coral terraces that extend 80 km along the Huon Peninsula, Papua New Guinea, the magnitude of sea level change during Heinrich Events was successfully reconstructed (Yokoyama et al., 2001 EPSL; Chappell et al., 1996 EPSL; Cutler et al., 2003). The H3 and H5 events are also well correlated with continuous sea level reconstructions using Red Sea oxygen isotope records (Siddall et al., 2003 Nature; Yokoyama and Esat, 2011Oceanography). Global ice sheet growth after 30 ka complicates interpretation of the Huon Peninsula record. However oxygen isotope data from the Japan Sea, a restricted margin sea with a shallow sill depth similar to the Red Sea, clearly captures the episode of H2 sea level change. The timing of these sea level excursions correlate well to the DSDP Site 609 detrital layers that are anchored in the latest Greenland ice core chronology (Obrochta et al., 2012 QSR). In the presentation, Antarctic ice sheet behavior during the H2 event will also be discussed using marginal seas oxygen records.

Vitamin D accelerates clinical recovery from tuberculosis: results of the SUCCINCT Study [Supplementary Cholecalciferol in recovery from tuberculosis]. A randomized, placebo-controlled, clinical trial of vitamin D supplementation in patients with pulmonary tuberculosis'.

PubMed

Salahuddin, Nawal; Ali, Farheen; Hasan, Zahra; Rao, Nisar; Aqeel, Masooma; Mahmood, Faisal

2013-01-19

Vitamin D enhances host protective immune responses to Mycobacterium tuberculosis by suppressing Interferon-gamma (IFN-g) and reducing disease associated inflammation in the host. The objectives of this study were to determine whether vitamin D supplementation to patients with tuberculosis (TB) could influence recovery. Two hundred and fifty nine patients with pulmonary TB were randomized to receive either 600,000 IU of Intramuscular vitamin D3 or placebo for 2 doses. Assessments were performed at 4, 8 and 12 weeks. Early secreted and T cell activated 6 kDa (ESAT6) and Mycobacterium tuberculosis sonicate (MTBs) antigen induced whole blood stimulated IFN-g responses were measured at 0 and 12 weeks. Statistical comparisons between outcome variables at 0 and 12 weeks were performed using Student's t-test and Chi2 tests. After 12 weeks, the vitamin D supplemented arm demonstrated significantly greater mean weight gain (kg)+3.75, (3.16-4.34) versus+2.61 (95% CI 1.99-3.23) p 0.009 and lesser residual disease by chest radiograph; number of zones involved 1.35 v/s 1.82 p 0.004 (95% CI 0.15, 0.79) and 50% or greater reduction in cavity size 106 (89.8%) v/s 111 (94.8%), p 0.035. Vitamin D supplementation led to significant increase in MTBs-induced IFN-g secretion in patients with baseline 'Deficient' 25-hydroxyvitamin D serum levels (p 0.021). Supplementation with high doses of vitamin D accelerated clinical, radiographic improvement in all TB patients and increased host immune activation in patients with baseline 'Deficient' serum vitamin D levels. These results suggest a therapeutic role for vitamin D in the treatment of TB. ClinicalTrials.gov; No. NCT01130311; URL: clinicaltrials.gov.

Selection, characterization, and application of DNA aptamers for detection of Mycobacterium tuberculosis secreted protein MPT64.

PubMed

Sypabekova, Marzhan; Bekmurzayeva, Aliya; Wang, Ronghui; Li, Yanbin; Nogues, Claude; Kanayeva, Damira

2017-05-01

Rapid detection of Mycobacterium tuberculosis (Mtb), an etiological agent of tuberculosis (TB), is important for global control of this disease. Aptamers have emerged as a potential rival for antibodies in therapeutics, diagnostics and biosensing due to their inherent characteristics. The aim of the current study was to select and characterize single-stranded DNA aptamers against MPT64 protein, one of the predominant secreted proteins of Mtb pathogen. Aptamers specific to MPT64 protein were selected in vitro using systematic evolution of ligands through exponential enrichment (SELEX) method. The selection was started with a pool of ssDNA library with randomized 40-nucleotide region. A total of 10 cycles were performed and seventeen aptamers with unique sequences were identified by sequencing. Dot Blot analysis was performed to monitor the SELEX process and to conduct the preliminary tests on the affinity and specificity of aptamers. Enzyme linked oligonucleotide assay (ELONA) showed that most of the aptamers were specific to the MPT64 protein with a linear correlation of R 2  = 0.94 for the most selective. Using Surface Plasmon Resonance (SPR), dissociation equilibrium constant K D of 8.92 nM was obtained. Bioinformatics analysis of the most specific aptamers revealed the existence of a conserved as well as distinct sequences and possible binding site on MPT64. The specificity was determined by testing non-target ESAT-6 and CFP-10. Negligible cross-reactivity confirmed the high specificity of the selected aptamer. The selected aptamer was further tested on clinical sputum samples using ELONA and had sensitivity and specificity of 91.3% and 90%, respectively. Microscopy, culture positivity and nucleotide amplification methods were used as reference standards. The aptamers studied could be further used for the development of medical diagnostic tools and detection assays for Mtb. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vaccines for Leprosy and Tuberculosis: Opportunities for Shared Research, Development, and Application

PubMed Central

Coppola, Mariateresa; van den Eeden, Susan J. F.; Robbins, Naoko; Wilson, Louis; Franken, Kees L. M. C.; Adams, Linda B.; Gillis, Tom P.; Ottenhoff, Tom H. M.; Geluk, Annemieke

2018-01-01

Tuberculosis (TB) and leprosy still represent significant public health challenges, especially in low- and lower middle-income countries. Both poverty-related mycobacterial diseases require better tools to improve disease control. For leprosy, there has been an increased emphasis on developing tools for improved detection of infection and early diagnosis of disease. For TB, there has been a similar emphasis on such diagnostic tests, while increased research efforts have also focused on the development of new vaccines. Bacille Calmette–Guérin (BCG), the only available TB vaccine, provides insufficient and inconsistent protection to pulmonary TB in adults. The impact of BCG on leprosy, however, is significant, and the introduction of new TB vaccines that might replace BCG could, therefore, have serious impact also on leprosy. Given the similarities in antigenic makeup between the pathogens Mycobacterium tuberculosis (Mtb) and M. leprae, it is well possible, however, that new TB vaccines could cross-protect against leprosy. New TB subunit vaccines currently evaluated in human phase I and II studies indeed often contain antigens with homologs in M. leprae. In this review, we discuss pre-clinical studies and clinical trials of subunit or whole mycobacterial vaccines for TB and leprosy and reflect on the development of vaccines that could provide protection against both diseases. Furthermore, we provide the first preclinical evidence of such cross-protection by Mtb antigen 85B (Ag85B)-early secretory antigenic target (ESAT6) fusion recombinant proteins in in vivo mouse models of Mtb and M. leprae infection. We propose that preclinical integration and harmonization of TB and leprosy research should be considered and included in global strategies with respect to cross-protective vaccine research and development. PMID:29535713

Enhancement of Human Antigen-Specific Memory T-Cell Responses by Interleukin-7 May Improve Accuracy in Diagnosing Tuberculosis▿ †

PubMed Central

Feske, Marsha; Nudelman, Rodolfo J.; Medina, Miguel; Lew, Justin; Singh, Manisha; Couturier, Jacob; Graviss, Edward A.; Lewis, Dorothy E.

2008-01-01

Children and immunocompromised adults are at an increased risk of tuberculosis (TB), but diagnosis is more challenging. Recently developed gamma interferon (IFN-γ) release assays provide increased sensitivity and specificity for diagnosis of latent TB, but their use is not FDA approved in immunocompromised or pediatric populations. Both populations have reduced numbers of T cells, which are major producers of IFN-γ. Interleukin 7 (IL-7), a survival cytokine, stabilizes IFN-γ message and increases protein production. IL-7 was added to antigen-stimulated lymphocytes to improve IFN-γ responses as measured by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Antigens used were tetanus toxoid (n = 10), p24 (from human immunodeficiency virus [HIV], n = 9), and TB peptides (n = 15). Keyhole limpet hemocyanin was used as a negative control, and phytohemagglutinin was the positive control. IL-7 improved antigen-specific responses to all antigens tested including tetanus toxoid, HIV type 1 p24, and TB peptides (ESAT-6 and CFP-10) with up to a 14-fold increase (mean = 3.8), as measured by ELISA. Increased IFN-γ responses from controls, HIV-positive patients, and TB patients were statistically significant, with P values of <0.05, 0.01, and 0.05, respectively. ELISPOT assay results confirmed ELISA findings (P values of <0.01, 0.02, and 0.03, respectively), with a strong correlation between the two tests (R2 = 0.82 to 0.99). Based on average background levels, IL-7 increased detection of IFN-γ by 39% compared to the level with antigen alone. Increased production of IFN-γ induced by IL-7 improves sensitivity of ELISA and ELISPOT assays for all antigens tested. Further enhancement of IFN-γ-based assays might improve TB diagnosis in those populations at highest risk for TB. PMID:18753334

Induction of a Specific Strong Polyantigenic Cellular Immune Response after Short-Term Chemotherapy Controls Bacillary Reactivation in Murine and Guinea Pig Experimental Models of Tuberculosis▿

PubMed Central

Guirado, Evelyn; Gil, Olga; Cáceres, Neus; Singh, Mahavir; Vilaplana, Cristina; Cardona, Pere-Joan

2008-01-01

RUTI is a therapeutic vaccine that is generated from detoxified and liposomed Mycobacterium tuberculosis cell fragments that has demonstrated its efficacy in the control of bacillus reactivation after short-term chemotherapy. The aim of this study was to characterize the cellular immune response generated after the therapeutic administration of RUTI and to corroborate the lack of toxicity of the vaccine. Mouse and guinea pig experimental models were infected with a low-dose M. tuberculosis aerosol. RUTI-treated animals showed the lowest bacillary load in both experimental models. RUTI also decreased the percentage of pulmonary granulomatous infiltration in the mouse and guinea pig models. This was not the case after Mycobacterium bovis BCG treatment. Cellular immunity was studied through the characterization of the intracellular gamma interferon (IFN-γ)-producing cells after the splenocytes' stimulation with M. tuberculosis-specific structural and growth-related antigens. Our data show that the difference between the therapeutic administration of BCG and RUTI resides mainly in the stronger activation of IFN-γ+ CD4+ cells and CD8+ cells against tuberculin purified protein derivative, ESAT-6, and Ag85B that RUTI generates. Both vaccines also triggered a specific immune response against the M. tuberculosis structural antigens Ag16kDa and Ag38kDa and a marked mRNA expression of IFN-γ, tumor necrosis factor, interleukin-12, inducible nitric oxide synthase, and RANTES in the lung. The results show that RUTI's therapeutic effect is linked not only to the induction of a Th1 response but also to the stimulation of a quicker and stronger specific immunity against structural and growth-related antigens that reduces both the bacillary load and the pulmonary pathology. PMID:18524883

Use of a Hybrid Edge Node-Centroid Node Approach to Thermal Modeling

NASA Technical Reports Server (NTRS)

Peabody, Hume L.

2010-01-01

A recent proposal submitted for an ESA mission required that models be delivered in ESARAD/ESAT AN formats. ThermalDesktop was the preferable analysis code to be used for model development with a conversion done as the final step before delivery. However, due to some differences between the capabilities of the two codes, a unique approach was developed to take advantage of the edge node capability of ThermalDesktop while maintaining the centroid node approach used by ESARAD. In essence, two separate meshes were used: one for conduction and one for radiation. The conduction calculations were eliminated from the radiation surfaces and the capacitance and radiative calculations were eliminated from the conduction surfaces. The resulting conduction surface nodes were coincident with all nodes of the radiation surface and were subsequently merged, while the nodes along the edges remained free. Merging of nodes on the edges of adjacent surfaces provided the conductive links between surfaces. Lastly, all nodes along edges were placed into the subnetwork and the resulting supernetwork included only the nodes associated with radiation surfaces. This approach had both benefits and disadvantages. The use of centroid, surface based radiation reduces the overall size of the radiation network, which is often the most computationally intensive part of the modeling process. Furthermore, using the conduction surfaces and allowing ThermalDesktop to calculate the conduction network can save significant time by not having to manually generate the couplings. Lastly, the resulting GMM/TMM models can be exported to formats which do not support edge nodes. One drawback, however, is the necessity to maintain two sets of surfaces. This requires additional care on the part of the analyst to ensure communication between the conductive and radiative surfaces in the resulting overall network. However, with more frequent use of this technique, the benefits of this approach can far outweigh the

BioTextQuest(+): a knowledge integration platform for literature mining and concept discovery.

PubMed

Papanikolaou, Nikolas; Pavlopoulos, Georgios A; Pafilis, Evangelos; Theodosiou, Theodosios; Schneider, Reinhard; Satagopam, Venkata P; Ouzounis, Christos A; Eliopoulos, Aristides G; Promponas, Vasilis J; Iliopoulos, Ioannis

2014-11-15

The iterative process of finding relevant information in biomedical literature and performing bioinformatics analyses might result in an endless loop for an inexperienced user, considering the exponential growth of scientific corpora and the plethora of tools designed to mine PubMed(®) and related biological databases. Herein, we describe BioTextQuest(+), a web-based interactive knowledge exploration platform with significant advances to its predecessor (BioTextQuest), aiming to bridge processes such as bioentity recognition, functional annotation, document clustering and data integration towards literature mining and concept discovery. BioTextQuest(+) enables PubMed and OMIM querying, retrieval of abstracts related to a targeted request and optimal detection of genes, proteins, molecular functions, pathways and biological processes within the retrieved documents. The front-end interface facilitates the browsing of document clustering per subject, the analysis of term co-occurrence, the generation of tag clouds containing highly represented terms per cluster and at-a-glance popup windows with information about relevant genes and proteins. Moreover, to support experimental research, BioTextQuest(+) addresses integration of its primary functionality with biological repositories and software tools able to deliver further bioinformatics services. The Google-like interface extends beyond simple use by offering a range of advanced parameterization for expert users. We demonstrate the functionality of BioTextQuest(+) through several exemplary research scenarios including author disambiguation, functional term enrichment, knowledge acquisition and concept discovery linking major human diseases, such as obesity and ageing. The service is accessible at http://bioinformatics.med.uoc.gr/biotextquest. g.pavlopoulos@gmail.com or georgios.pavlopoulos@esat.kuleuven.be Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University

Detection of a combination of serum IgG and IgA antibodies against selected mycobacterial targets provides promising diagnostic signatures for active TB

PubMed Central

Chegou, Novel N.; Kriel, Belinda; Jacobs, Ruschca; Kidd, Martin; Loxton, Andre G.; Kaempfer, Susanne; Singh, Mahavir; Walzl, Gerhard

2017-01-01

Immunoglobulin G (IgG) based tests for the diagnosis of active tuberculosis (TB) disease often show a lack of specificity in TB endemic regions, which is mainly due to a high background prevalence of LTBI. Here, we investigated the combined performance of the responses of different Ig classes to selected mycobacterial antigens in primary healthcare clinic attendees with signs and symptoms suggestive of TB. The sensitivity and specificity of IgA, IgG and/or IgM to LAM and 7 mycobacterial protein antigens (ESAT-6, Tpx, PstS1, AlaDH, MPT64, 16kDa and 19kDa) and 2 antigen combinations (TUB, TB-LTBI) in the plasma of 63 individuals who underwent diagnostic work-up for TB after presenting with symptoms and signs compatible with possible active TB were evaluated. Active TB was excluded in 42 individuals of whom 21 has LTBI whereas active TB was confirmed in 21 patients of whom 19 had a follow-up blood draw at the end of 6-month anti-TB treatment. The leading single serodiagnostic markers to differentiate between the presence or absence of active TB were anti-16 kDa IgA, anti-MPT64 IgA with sensitivity and specificity of 90%/90% and 95%/90%, respectively. The combined use of 3 or 4 antibodies further improved this performance to accuracies above 95%. After successful completion of anti-TB treatment at month 6, the levels of 16 kDa IgA and 16 kDa IgM dropped significantly whereas LAM IgG and TB-LTBI IgG increased. These results show the potential of extending investigation of anti-tuberculous IgG responses to include IgM and IgA responses against selected protein and non-protein antigens in differentiating active TB from other respiratory diseases in TB endemic settings. PMID:28415587

Detection of a combination of serum IgG and IgA antibodies against selected mycobacterial targets provides promising diagnostic signatures for active TB.

PubMed

Awoniyi, Dolapo O; Baumann, Ralf; Chegou, Novel N; Kriel, Belinda; Jacobs, Ruschca; Kidd, Martin; Loxton, Andre G; Kaempfer, Susanne; Singh, Mahavir; Walzl, Gerhard

2017-06-06

Immunoglobulin G (IgG) based tests for the diagnosis of active tuberculosis (TB) disease often show a lack of specificity in TB endemic regions, which is mainly due to a high background prevalence of LTBI. Here, we investigated the combined performance of the responses of different Ig classes to selected mycobacterial antigens in primary healthcare clinic attendees with signs and symptoms suggestive of TB. The sensitivity and specificity of IgA, IgG and/or IgM to LAM and 7 mycobacterial protein antigens (ESAT-6, Tpx, PstS1, AlaDH, MPT64, 16kDa and 19kDa) and 2 antigen combinations (TUB, TB-LTBI) in the plasma of 63 individuals who underwent diagnostic work-up for TB after presenting with symptoms and signs compatible with possible active TB were evaluated. Active TB was excluded in 42 individuals of whom 21 has LTBI whereas active TB was confirmed in 21 patients of whom 19 had a follow-up blood draw at the end of 6-month anti-TB treatment. The leading single serodiagnostic markers to differentiate between the presence or absence of active TB were anti-16 kDa IgA, anti-MPT64 IgA with sensitivity and specificity of 90%/90% and 95%/90%, respectively. The combined use of 3 or 4 antibodies further improved this performance to accuracies above 95%. After successful completion of anti-TB treatment at month 6, the levels of 16 kDa IgA and 16 kDa IgM dropped significantly whereas LAM IgG and TB-LTBI IgG increased. These results show the potential of extending investigation of anti-tuberculous IgG responses to include IgM and IgA responses against selected protein and non-protein antigens in differentiating active TB from other respiratory diseases in TB endemic settings.

Solid Biomass Consumption in Households and Greenhouse Gas Emission Reduction in Latvia / CIETĀS Biomasas PATĒRIŅŠ un SILTUMNĪCEFEKTA GĀZU Emisiju SAMAZINĀŠANAS PERSPEKTĪVA Latvijas MĀJSAIMNIECĪBĀS

NASA Astrophysics Data System (ADS)

Kudrenickis, I.; Klavs, G.

2013-12-01

īs. Salīdzinot kurināmā patēriņa un CH4 emisiju apjoma izmaiņas, ir aprēķināts skaitliskais rādītājs, kas raksturo biomasas kurināmā patēriņa un CH4 emisiju "atsaisti" ES valstīs analizējamā laika posmā. Lai kvantitatīvi novērtētu CH4 emisiju samazināšanas perspektīvu Latvijas mājsaimniecību sektorā, autori analizē divus attīstības scenārijus, kas paredz dažādus mājsaimniecību centrālajā apkurē izmantoto koksnes sadedzināšanas iekārtu efektivitātes pieaugumus.

Endosomal escape and siRNA delivery with cationic shell crosslinked knedel-like nanoparticles with tunable buffering capacities

PubMed Central

Shrestha, Ritu; Elsabahy, Mahmoud; Florez-Malaver, Stephanie; Samarajeewa, Sandani; Wooley, Karen L.

2012-01-01

Cationic shell crosslinked knedel-like nanoparticles (cSCKs) have emerged as a highly efficient transfection agent for nucleic acids delivery. In this study, a new class of cSCKs with tunable buffering capacities has been developed by altering the amounts of histamines and primary amines incorporated into their crosslinked shell regions. The effect of histamine content of these nanoparticles with a hydrodynamic diameter of ca. 20 nm, on the siRNA-binding affinity, cytotoxicity, immunogenicity, and transfection efficiency was investigated. The modification of cSCKs with histamine was found to reduce the siRNA-binding affinity and cellular binding. On the other hand, it significantly reduced the toxicity and immunogenicity of the nanoparticles with subsequent increase in the transfection efficiency. In addition, escape from endosomes was facilitated by having two species of low and high pKas (i.e. histamine and primary amine groups, respectively), as demonstrated by the potentiometric titration experiments and the effect of bafilomycin A1, an inhibitor of the endosomal acidification, on the transfection efficiency of cSCKs. Histamine modification of 15 mol% was a threshold, above which cSCKs with higher histamine content completely lost the ability to bind siRNA and to transfect cells. This study highlights the potential of histamine incorporation to augment the gene silencing activity of cationic nanoparticles, reduce their toxicity, and increase their biocompatibility, which is of particular importance in the design of nucleic acids delivery vectors. PMID:22901966

Kinetic analysis of manure pyrolysis and combustion processes.

PubMed

Fernandez-Lopez, M; Pedrosa-Castro, G J; Valverde, J L; Sanchez-Silva, L

2016-12-01

Due to the depletion of fossil fuel reserves and the environmental issues derived from their use, biomass seems to be an excellent source of renewable energy. In this work, the kinetics of the pyrolysis and combustion of three different biomass waste samples (two dairy manure samples before (Pre) and after (Dig R) anaerobic digestion and one swine manure sample (SW)) was studied by means of thermogravimetric analysis. In this work, three iso-conversional methods (Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS)) were compared with the Coats-Redfern method. The E a values of devolatilization stages were in the range of 152-170kJ/mol, 148-178kJ/mol and 156-209kJ/mol for samples Pre, Dig R and SW, respectively. Concerning combustion process, char oxidation stages showed lower E a values than that obtained for the combustion devolatilization stage, being in the range of 140-175kJ/mol, 178-199kJ/mol and 122-144kJ/mol for samples Pre, Dig R and SW, respectively. These results were practically the same for samples Pre and Dig R, which means that the kinetics of the thermochemical processes were not affected by anaerobic digestion. Finally, the distributed activation energy model (DAEM) and the pseudo-multi component stage model (PMSM) were applied to predict the weight loss curves of pyrolysis and combustion. DAEM was the best model that fitted the experimental data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bootstrap current control studies in the Wendelstein 7-X stellarator using the free-plasma-boundary version of the SIESTA MHD equilibrium code

NASA Astrophysics Data System (ADS)

Peraza-Rodriguez, H.; Reynolds-Barredo, J. M.; Sanchez, R.; Tribaldos, V.; Geiger, J.

2018-02-01

The recently developed free-plasma-boundary version of the SIESTA MHD equilibrium code (Hirshman et al 2011 Phys. Plasmas 18 062504; Peraza-Rodriguez et al 2017 Phys. Plasmas 24 082516) is used for the first time to study scenarios with considerable bootstrap currents for the Wendelstein 7-X (W7-X) stellarator. Bootstrap currents in the range of tens of kAs can lead to the formation of unwanted magnetic island chains or stochastic regions within the plasma and alter the boundary rotational transform due to the small shear in W7-X. The latter issue is of relevance since the island divertor operation of W7-X relies on a proper positioning of magnetic island chains at the plasma edge to control the particle and energy exhaust towards the divertor plates. Two scenarios are examined with the new free-plasma-boundary capabilities of SIESTA: a freely evolving bootstrap current one that illustrates the difficulties arising from the dislocation of the boundary islands, and a second one in which off-axis electron cyclotron current drive (ECCD) is applied to compensate the effects of the bootstrap current and keep the island divertor configuration intact. SIESTA finds that off-axis ECCD is indeed able to keep the location and phase of the edge magnetic island chain unchanged, but it may also lead to an undesired stochastization of parts of the confined plasma if the EC deposition radial profile becomes too narrow.

Analysis of Dermatologic Events in Vemurafenib-Treated Patients With Melanoma

PubMed Central

Duvic, Madeleine; Hauschild, Axel; Prieto, Victor G.; Robert, Caroline; Schadendorf, Dirk; Kim, Caroline C.; McCormack, Christopher J.; Myskowski, Patricia L.; Spleiss, Olivia; Trunzer, Kerstin; Su, Fei; Nelson, Betty; Nolop, Keith B.; Grippo, Joseph F.; Lee, Richard J.; Klimek, Matthew J.; Troy, James L.; Joe, Andrew K.

2013-01-01

Background. Vemurafenib has been approved for the treatment of patients with advanced BRAFV600E-mutant melanoma. This report by the Vemurafenib Dermatology Working Group presents the characteristics of dermatologic adverse events (AEs) that occur in vemurafenib-treated patients, including cutaneous squamous cell carcinoma (cuSCC). Methods. Dermatologic AEs were assessed from three ongoing trials of BRAFV600E mutation-positive advanced melanoma. Histologic central review and genetic characterization were completed for a subset of cuSCC lesions. Results. A total of 520 patients received vemurafenib. The most commonly reported AEs were dermatologic AEs, occurring in 92%–95% of patients. Rash was the most common AE (64%–75% of patients), and the most common types were rash not otherwise specified, erythema, maculopapular rash, and folliculitis. Rash development did not appear to correlate with tumor response. Photosensitivity occurred in 35%–63% of patients, and palmar-plantar erythrodysesthesia (PPE) occurred in 8%–10% of patients. The severity of rash, photosensitivity, and PPE were mainly grade 1 or 2. In all, 19%–26% of patients developed cuSCC, mostly keratoacanthomas (KAs). The majority of patients with cuSCC continued therapy without dose reduction after resection. Genetic analysis of 29 cuSCC/KA samples demonstrated HRAS mutations in 41%. Conclusions. Dermatologic AEs associated with vemurafenib treatment in patients with melanoma were generally manageable with supportive care measures. Dose interruptions and/or reductions were required in <10% of patients. PMID:23457002

Blockade of interleukin-6 signalling with siltuximab enhances melphalan cytotoxicity in preclinical models of multiple myeloma.

PubMed

Hunsucker, Sally A; Magarotto, Valeria; Kuhn, Deborah J; Kornblau, Steven M; Wang, Michael; Weber, Donna M; Thomas, Sheeba K; Shah, Jatin J; Voorhees, Peter M; Xie, Hong; Cornfeld, Mark; Nemeth, Jeffrey A; Orlowski, Robert Z

2011-03-01

Signalling through the interleukin (IL)-6 pathway induces proliferation and drug resistance of multiple myeloma cells. We therefore sought to determine whether the IL-6-neutralizing monoclonal antibody siltuximab, formerly CNTO 328, could enhance the activity of melphalan, and to examine some of the mechanisms underlying this interaction. Siltuximab increased the cytotoxicity of melphalan in KAS-6/1, INA-6, ANBL-6, and RPMI 8226 human myeloma cell lines (HMCLs) in an additive-to-synergistic manner, and sensitized resistant RPMI 8226.LR5 cells to melphalan. These anti-proliferative effects were accompanied by enhanced activation of drug-specific apoptosis in HMCLs grown in suspension, and in HMCLs co-cultured with a human-derived stromal cell line. Siltuximab with melphalan enhanced activation of caspase-8, caspase-9, and the downstream effector caspase-3 compared with either of the single agents. This increased induction of cell death occurred in association with enhanced Bak activation. Neutralization of IL-6 also suppressed signalling through the phosphoinositide 3-kinase/Akt pathway, as evidenced by decreased phosphorylation of Akt, p70 S6 kinase and 4E-BP1. Importantly, the siltuximab/melphalan regimen demonstrated enhanced anti-proliferative effects against primary plasma cells derived from patients with myeloma, monoclonal gammopathy of undetermined significance, and amyloidosis. These studies provide a rationale for translation of siltuximab into the clinic in combination with melphalan-based therapies. © 2011 Blackwell Publishing Ltd.

Multi-Objective Optimization of Transmission Lines / Elektropārvades Līnijas Daudzkriteriālā Optimizācija

NASA Astrophysics Data System (ADS)

Berjozkina, S.; Sauhats, A.; Neimane, V.

2013-10-01

Introduction of new advanced electrical connections into a transmission grid reduces the capacity of existing overhead lines (OHLs). At the same time, designing & building of new OHLs and substations involves considerable technical, environmental and economical problems. The authors propose a concept of the multi-objective optimization for selection of transmission line routes, towers (their type, placement and geometry), of conductors, insulators, dampers, earthing and lightning protection systems, span lengths, etc.. The optimization is organized in five stages. At the first and second stages a search for optimum solutions is performed along with determination of the main impacting factors. The next two stages present a two-objective optimization based on Pareto's approach. At the last stage (exemplified by a case study), the probability of the restriction removal conditions is assessed, and preventive measures are identified. The presented approach uses a real line design and is intended for minimizing the total invested capital and maximizing the net present value. In the framework of this approach 20 alternatives have been elaborated, which can successfully be applied in the cases described in the paper. Elektropārvades tīklam rodas nepieciešamība pēc jauniem elektriskajiem pieslēgumiem, kas noved pie esošo gaisvadu līniju jaudas nepietiekamības. Viens no iespējamajiem pastāvošās problēmas risinājumiem ir jaunu gaisvadu līniju un apakšstacijas būvniecība. Gaisvadu līniju projektēšana ir saistīta ar ievērojamām tehniskām, vides un ekonomiskām problēmām. Darbā aprakstīta elektropārvades līnijas optimālās trases izvēles daudzkritēriju optimizācijas koncepcija, ieskaitot balstu tipa, balstu izvietojuma koordināšu, balstu ģeometrijas, vadu tipu un parametru, izolatoru tipu, vibroslāpētāju tipu, zibensaizsardzības un zemēšanas sistēmu, kā arī laidumu garumu izvēles optimizāciju. Optimizācijas uzdevums tiek organiz

Pulmonary immune responses to Mycobacterium tuberculosis in exposed individuals

PubMed Central

Ernst, Martin; Lange, Christoph; Stenger, Steffen; Kaufmann, Stefan H. E.; Reiling, Norbert; Schaberg, Tom; van der Merwe, Lize; Maertzdorf, Jeroen

2017-01-01

Background Blood based Interferon-(IFN)-γ release assays (IGRAs) have a poor predictive value for the development of tuberculosis. This study aimed to investigate the correlation between IGRAs and pulmonary immune responses in tuberculosis contacts in Germany. Methods IGRAs were performed on bronchoalveolar lavage (BAL) cells and peripheral blood from close healthy contacts of patients with culturally confirmed tuberculosis. Cellular BAL composition was determined by flow cytometry. BAL cells were co-cultured with three strains of Mycobacterium tuberculosis (Mtb) and Mtb derived antigens including Purified Protein Derivative (PPD), 6 kD Early Secretory Antigenic Target (ESAT-6) and 10 kD Culture Filtrate Protein (CFP-10). Levels of 29 cytokines and chemokines were analyzed in the supernatants by multiplex assay. Associations and effects were examined using linear mixed-effects models. Results There were wide variations of inter-individual cytokine levels in BAL cell culture supernatants. Mycobacterial infection and stimulation with PPD showed a clear induction of several macrophage and lymphocyte associated cytokines, reflecting activation of these cell types. No robust correlation between cytokine patterns and blood IGRA status of the donor was observed, except for slightly higher Interleukin-2 (IL-2) responses in BAL cells from IGRA-positive donors upon mycobacterial infection compared to cells from IGRA-negative donors. Stronger correlations were observed when cytokine patterns were stratified according to BAL IGRA status. BAL cells from donors with BAL IGRA-positive responses produced significantly more IFN-γ and IL-2 upon PPD stimulation and mycobacterial infection than cells from BAL IGRA-negative individuals. Correlations between BAL composition and basal cytokine release from unstimulated cells were suggestive of pre-activated lymphocytes but impaired macrophage activity in BAL IGRA-positive donors, in contrast to BAL IGRA-negative donors. Conclusions In

Antagonism between Staphylococcus epidermidis and Propionibacterium acnes and its genomic basis.

PubMed

Christensen, Gitte J M; Scholz, Christian F P; Enghild, Jan; Rohde, Holger; Kilian, Mogens; Thürmer, Andrea; Brzuszkiewicz, Elzbieta; Lomholt, Hans B; Brüggemann, Holger

2016-02-29

Propionibacterium acnes and Staphylococcus epidermidis live in close proximity on human skin, and both bacterial species can be isolated from normal and acne vulgaris-affected skin sites. The antagonistic interactions between the two species are poorly understood, as well as the potential significance of bacterial interferences for the skin microbiota. Here, we performed simultaneous antagonism assays to detect inhibitory activities between multiple isolates of the two species. Selected strains were sequenced to identify the genomic basis of their antimicrobial phenotypes. First, we screened 77 P. acnes strains isolated from healthy and acne-affected skin, and representing all known phylogenetic clades (I, II, and III), for their antimicrobial activities against 12 S. epidermidis isolates. One particular phylogroup (I-2) exhibited a higher antimicrobial activity than other P. acnes phylogroups. All genomes of type I-2 strains carry an island encoding the biosynthesis of a thiopeptide with possible antimicrobial activity against S. epidermidis. Second, 20 S. epidermidis isolates were examined for inhibitory activity against 25 P. acnes strains. The majority of S. epidermidis strains were able to inhibit P. acnes. Genomes of S. epidermidis strains with strong, medium and no inhibitory activities against P. acnes were sequenced. Genome comparison underlined the diversity of S. epidermidis and detected multiple clade- or strain-specific mobile genetic elements encoding a variety of functions important in antibiotic and stress resistance, biofilm formation and interbacterial competition, including bacteriocins such as epidermin. One isolate with an extraordinary antimicrobial activity against P. acnes harbors a functional ESAT-6 secretion system that might be involved in the antimicrobial activity against P. acnes via the secretion of polymorphic toxins. Taken together, our study suggests that interspecies interactions could potentially jeopardize balances in the skin

Characterization of Effector and Memory T Cell Subsets in the Immune Response to Bovine Tuberculosis in Cattle

PubMed Central

Maggioli, Mayara F.; Palmer, Mitchell V.; Thacker, Tyler C.; Vordermeier, H. Martin; Waters, W. Ray

2015-01-01

Cultured IFN-γ ELISPOT assays are primarily a measure of central memory T cell (Tcm) responses with humans; however, this important subset of lymphocytes is poorly characterized in cattle. Vaccine-elicited cultured IFN-γ ELISPOT responses correlate with protection against bovine tuberculosis in cattle. However, whether this assay measures cattle Tcm responses or not is uncertain. The objective of the present study was to characterize the relative contribution of Tcm (CCR7+, CD62Lhi, CD45RO+), T effector memory (Tem, defined as: CCR7-, CD62Llow/int, CD45RO+), and T effector cells (CCR7-, CD62L-/low, CD45RO-), in the immune response to Mycobacterium bovis. Peripheral blood mononuclear cells (PBMC) from infected cattle were stimulated with a cocktail of M. bovis purified protein derivative, rTb10.4 and rAg85A for 13 days with periodic addition of fresh media and rIL-2. On day 13, cultured PBMC were re-stimulated with medium alone, rESAT-6:CFP10 or PPDb with fresh autologous adherent cells for antigen presentation. Cultured cells (13 days) or fresh PBMCs (ex vivo response) from the same calves were analyzed for IFN-γ production, proliferation, and CD4, CD45RO, CD62L, CD44, and CCR7 expression via flow cytometry after overnight stimulation. In response to mycobacterial antigens, ~75% of CD4+ IFN-γ+ cells in long-term cultures expressed a Tcm phenotype while less than 10% of the ex vivo response consisted of Tcm cells. Upon re-exposure to antigen, long-term cultured cells were highly proliferative, a distinctive characteristic of Tcm, and the predominant phenotype within the long-term cultures switched from Tcm to Tem. These findings suggest that proliferative responses of Tcm cells to some extent occurs simultaneously with reversion to effector phenotypes (mostly Tem). The present study characterizes Tcm cells of cattle and their participation in the response to M. bovis infection. PMID:25879774

Molecular Assays for Determining Mycobacterium leprae Viability in Tissues of Experimentally Infected Mice

PubMed Central

Davis, Grace L.; Ray, Nashone A.; Lahiri, Ramanuj; Gillis, Thomas P.; Krahenbuhl, James L.; Williams, Diana L.; Adams, Linda B.

2013-01-01

Background The inability of Mycobacterium leprae to grow on axenic media has necessitated specialized techniques in order to determine viability of this organism. The purpose of this study was to develop a simple and sensitive molecular assay for determining M. leprae viability directly from infected tissues. Methodology/Principle Findings Two M. leprae-specific quantitative reverse transcription PCR (qRT-PCR) assays based on the expression levels of esxA, encoding the ESAT-6 protein, and hsp18, encoding the heat shock 18 kDa protein, were developed and tested using infected footpad (FP) tissues of both immunocompetent and immunocompromised (athymic nu/nu) mice. In addition, the ability of these assays to detect the effects of anti-leprosy drug treatment on M. leprae viability was determined using rifampin and rifapentine, each at 10 mg/kg for 1, 5, or 20 daily doses, in the athymic nu/nu FP model. Molecular enumeration (RLEP PCR) and viability determinations (qRT-PCR) were performed via Taqman methodology on DNA and RNA, respectively, purified from ethanol-fixed FP tissue and compared with conventional enumeration (microscopic counting of acid fast bacilli) and viability assays (radiorespirometry, viability staining) which utilized bacilli freshly harvested from the contralateral FP. Both molecular and conventional assays demonstrated growth and high viability of M. leprae in nu/nu FPs over a 4 month infection period. In contrast, viability was markedly decreased by 8 weeks in immunocompetent mice. Rifapentine significantly reduced bacterial viability after 5 treatments, whereas rifampin required up to 20 treatments for the same efficacy. Neither drug was effective after a single treatment. In addition, host gene expression was monitored with the same RNA preparations. Conclusions hsp18 and esxA qRT-PCR are sensitive molecular indicators, reliably detecting viability of M. leprae in tissues without the need for bacterial isolation or immediate processing, making

Molecular assays for determining Mycobacterium leprae viability in tissues of experimentally infected mice.

PubMed

Davis, Grace L; Ray, Nashone A; Lahiri, Ramanuj; Gillis, Thomas P; Krahenbuhl, James L; Williams, Diana L; Adams, Linda B

2013-01-01

The inability of Mycobacterium leprae to grow on axenic media has necessitated specialized techniques in order to determine viability of this organism. The purpose of this study was to develop a simple and sensitive molecular assay for determining M. leprae viability directly from infected tissues. Two M. leprae-specific quantitative reverse transcription PCR (qRT-PCR) assays based on the expression levels of esxA, encoding the ESAT-6 protein, and hsp18, encoding the heat shock 18 kDa protein, were developed and tested using infected footpad (FP) tissues of both immunocompetent and immunocompromised (athymic nu/nu) mice. In addition, the ability of these assays to detect the effects of anti-leprosy drug treatment on M. leprae viability was determined using rifampin and rifapentine, each at 10 mg/kg for 1, 5, or 20 daily doses, in the athymic nu/nu FP model. Molecular enumeration (RLEP PCR) and viability determinations (qRT-PCR) were performed via Taqman methodology on DNA and RNA, respectively, purified from ethanol-fixed FP tissue and compared with conventional enumeration (microscopic counting of acid fast bacilli) and viability assays (radiorespirometry, viability staining) which utilized bacilli freshly harvested from the contralateral FP. Both molecular and conventional assays demonstrated growth and high viability of M. leprae in nu/nu FPs over a 4 month infection period. In contrast, viability was markedly decreased by 8 weeks in immunocompetent mice. Rifapentine significantly reduced bacterial viability after 5 treatments, whereas rifampin required up to 20 treatments for the same efficacy. Neither drug was effective after a single treatment. In addition, host gene expression was monitored with the same RNA preparations. hsp18 and esxA qRT-PCR are sensitive molecular indicators, reliably detecting viability of M. leprae in tissues without the need for bacterial isolation or immediate processing, making these assays applicable for in vivo drug screening and

Engineering Mycobacteria for the Production of Self-Assembling Biopolyesters Displaying Mycobacterial Antigens for Use as a Tuberculosis Vaccine.

PubMed

Lee, Jason W; Parlane, Natalie A; Rehm, Bernd H A; Buddle, Bryce M; Heiser, Axel

2017-03-01

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis or Mycobacterium bovis and still remains one of the world's biggest global health burdens. Recently, engineered polyhydroxyalkanoate (PHA) biobeads that were produced in both Escherichia coli and Lactococcus lactis and displayed mycobacterial antigens were found to induce significant cell-mediated immune responses in mice. We observed that such PHA beads contained host cell proteins as impurities, which we hypothesized to have the potential to induce immunity. In this study, we aimed to develop PHA beads produced in mycobacteria (mycobacterial PHA biobeads [MBB]) and test their potential as a TB vaccine in a mouse model. As a model organism, nonpathogenic Mycobacterium smegmatis was engineered to produce MBB or MBB with immobilized mycobacterial antigens Ag85A and ESAT-6 on their surface (A:E-MBB). Three key enzymes involved in the poly(3-hydroxybutyric acid) pathway, namely, β-ketothiolase (PhaA), acetoacetyl-coenzyme A reductase (PhaB), and PHA synthase (PhaC), were engineered into E. coli - Mycobacterium shuttle plasmids and expressed in trans Immobilization of specific antigens to the surface of the MBB was achieved by creating a fusion with the PHA synthase which remains covalently attached to the polyester core, resulting in PHA biobeads displaying covalently immobilized antigens. E-MBB, and an M. smegmatis vector control (MVC) were used in a mouse immunology trial, with comparison to phosphate-buffered saline (PBS)-vaccinated and Mycobacterium bovis BCG-vaccinated groups. We successfully produced MBB and A:E-MBB and used them as vaccines to induce a cellular immune response to mycobacterial antigens. IMPORTANCE Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis or Mycobacterium bovis and still remains one of the world's biggest global health burdens. In this study, we produced polyhydroxyalkanoate (PHA) biobeads in mycobacteria and used them as vaccines to induce a cellular

Engineering Mycobacteria for the Production of Self-Assembling Biopolyesters Displaying Mycobacterial Antigens for Use as a Tuberculosis Vaccine

PubMed Central

Lee, Jason W.; Parlane, Natalie A.; Rehm, Bernd H. A.; Buddle, Bryce M.

2017-01-01

ABSTRACT Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis or Mycobacterium bovis and still remains one of the world's biggest global health burdens. Recently, engineered polyhydroxyalkanoate (PHA) biobeads that were produced in both Escherichia coli and Lactococcus lactis and displayed mycobacterial antigens were found to induce significant cell-mediated immune responses in mice. We observed that such PHA beads contained host cell proteins as impurities, which we hypothesized to have the potential to induce immunity. In this study, we aimed to develop PHA beads produced in mycobacteria (mycobacterial PHA biobeads [MBB]) and test their potential as a TB vaccine in a mouse model. As a model organism, nonpathogenic Mycobacterium smegmatis was engineered to produce MBB or MBB with immobilized mycobacterial antigens Ag85A and ESAT-6 on their surface (A:E-MBB). Three key enzymes involved in the poly(3-hydroxybutyric acid) pathway, namely, β-ketothiolase (PhaA), acetoacetyl-coenzyme A reductase (PhaB), and PHA synthase (PhaC), were engineered into E. coli-Mycobacterium shuttle plasmids and expressed in trans. Immobilization of specific antigens to the surface of the MBB was achieved by creating a fusion with the PHA synthase which remains covalently attached to the polyester core, resulting in PHA biobeads displaying covalently immobilized antigens. MBB, A:E-MBB, and an M. smegmatis vector control (MVC) were used in a mouse immunology trial, with comparison to phosphate-buffered saline (PBS)-vaccinated and Mycobacterium bovis BCG-vaccinated groups. We successfully produced MBB and A:E-MBB and used them as vaccines to induce a cellular immune response to mycobacterial antigens. IMPORTANCE Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis or Mycobacterium bovis and still remains one of the world's biggest global health burdens. In this study, we produced polyhydroxyalkanoate (PHA) biobeads in mycobacteria and used them as vaccines to

The effect of HIV coinfection, HAART and TB treatment on cytokine/chemokine responses to Mycobacterium tuberculosis (Mtb) antigens in active TB patients and latently Mtb infected individuals.

PubMed

Kassa, Desta; de Jager, Wilco; Gebremichael, Gebremedhin; Alemayehu, Yodit; Ran, Leonie; Fransen, Justin; Wolday, Dawit; Messele, Tsehaynesh; Tegbaru, Belete; Ottenhoff, Tom H M; van Baarle, Debbie

2016-01-01

Identification of Mtb specific induced cytokine/chemokine host biomarkers could assist in developing novel diagnostic, prognostic and therapeutic tools for TB. Levels of IFN-γ, IL-2, IL-17, IL-10, IP-10 and MIP-1α were measured in supernatants of whole blood stimulated with Mtb specific fusion protein ESAT-6/CFP-10 using xMAP technology. The study groups were HIV positive TB patients (HIV(+)TB(+)), HIV negative TB patients (HIV(-)TB(+)), HIV positive tuberculin skin test positive (TST+) (HIV(+)TST(+)), HIV negative TST+ (HIV(-)TST(+)), and HIV(-)TST(-) individuals. Compared to HIV(-)TST(-), latent TB infection led to increased levels of IP-10, IFN-γ and IL-17, while levels of IL-2 and IP-10 were increased with active TB. Levels of IFN-γ, IL-17, MIP-1α, and IL-10 were increased in HIV(-)TST(+) individuals compared to HIV(-)TB(+) patients. HIV coinfection decreased the level of IFN-γ, IL-17, IP-10 and IL-2. After six months (M6) of anti-TB treatment (ATT) in HIV(-)TB(+) patients, IFN-γ, IL-10, and MIP-1α levels normalized. After M6 and M18 of ATT plus HAART in HIV(+)TB(+) patients, levels of MIP-1α and IL-10 normalized, while this was not the case for IFN-γ, IL-2, IL-17, and IP-10 levels. In HIV(+)TST(+) patients on HAART, levels of IFN-γ, IL-17, IL-10 and MIP-1α normalized, while no change in the levels of IL-2 and IP-10 were observed. In conclusion, the simultaneous measurement of IFN-γ, IL-17 and IP-10 may assist in diagnosing LTBI; IL-2 and IP-10 may assist in diagnosing active TB; while IFN-γ, IL-17, MIP-1α, and IL-10 levels could help to discriminate LTBI and active TB. In addition, IL-10 and MIP-1α levels could help to monitor responses to TB treatment and HAART. Copyright © 2015 Elsevier Ltd. All rights reserved.

The D-galactose specific lectin of field bean (Dolichos lablab) seed binds sugars with extreme negative cooperativity and half-of-the-sites binding.

PubMed

Rao, Devavratha H; Gowda, Lalitha R

2012-08-15

The field bean (Dolichos lablab) lectin designated as PPO-haemagglutinin (DLL-II) is bifunctional, exhibiting both polyphenol oxidase and haemagglutinating activity. The lectin is unusual in that it binds galactose (Gal), lactose (Lac) and N-acetylgalactosamine (GalNAc) only in the presence of (NH₄)₂SO₄ and exhibits negative cooperativity and half-of-the-sites binding. Circular dichroism, isothermal titration calorimetry and fluorescence quenching were used to assess the sugar binding in the presence of (NH₄)₂O₄. Comparison of the near-UV CD spectra with and without bound sugar revealed ligand induced conformational changes. The intrinsic fluorescence quenching data indicate that DLL-II exhibits weak binding to Gal in the presence of (NH₄)₂SO₄ with a stoichiometry of one bound ligand per dimer. ITC data fitted using a two sets of sites binding model presented a similar picture. The K(a)'s for Gal, Lac and GalNAc in the presence of (NH₄)₂SO₄ were 0.16±0.002, 0.21±0.004 and 8.45±0.78 (×10⁻³) M⁻¹ respectively. The Hill plot for the binding of these sugars to DLL-II was curvilinear with a tangent slope <1.0 indicating negative cooperativity. DLL-II thus exhibits half-of-the-site binding, an extreme form of negative cooperativity in which the second ligand does not bind at all. This is the first report of a legume lectin, exhibiting half-of-the-sites binding. Copyright © 2012 Elsevier Inc. All rights reserved.

Electrostatic dominoes: long distance propagation of mutational effects in photosynthetic reaction centers of Rhodobacter capsulatus.

PubMed

Sebban, P; Maróti, P; Schiffer, M; Hanson, D K

1995-07-04

Two point mutants from the purple bacterium Rhodobacter capsulatus, both modified in the M protein of the photosynthetic reaction center, have been studied by flash-induced absorbance spectroscopy. These strains carry either the M231Arg --> Leu or M43ASN --> Asp mutations, which are located 9 and 15 A, respectively, from the terminal electron acceptor QB. In the wild-type Rb. sphaeroides structure, M231Arg is involved in a conserved salt bridge with H125Glu and H232Glu and M43Asn is located among several polar residues that form or surround the QB binding site. These substitutions were originally uncovered in phenotypic revertants isolated from the photosynthetically incompetent L212Glu-L213Asp --> Ala-Ala site-specific double mutant. As second-site suppressor mutations, they have been shown to restore the proton transfer function that is interrupted in the L212Ala-L213Ala double mutant. The electrostatic effects that are induced in reaction centers by the M231Arg --> Leu and M43Asn --> Asp substitutions are roughly the same in either the double-mutant or wild-type backgrounds. In a reaction center that is otherwise wild type in sequence, they decrease the free energy gap between the QA- and QB- states by 24 +/- 5 and 45 +/- 5 meV, respectively. The pH dependences of K2, the QA-QB <--> QAQB- equilibrium constant, are altered in reaction centers that carry either of these substitutions, revealing differences in the pKas of titratable groups compared to the wild type.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular mechanisms for generating transmembrane proton gradients

PubMed Central

Gunner, M.R.; Amin, Muhamed; Zhu, Xuyu; Lu, Jianxun

2013-01-01

Membrane proteins use the energy of light or high energy substrates to build a transmembrane proton gradient through a series of reactions leading to proton release into the lower pH compartment (P-side) and proton uptake from the higher pH compartment (N-side). This review considers how the proton affinity of the substrates, cofactors and amino acids are modified in four proteins to drive proton transfers. Bacterial reaction centers (RCs) and photosystem II (PSII) carry out redox chemistry with the species to be oxidized on the P-side while reduction occurs on the N-side of the membrane. Terminal redox cofactors are used which have pKas that are strongly dependent on their redox state, so that protons are lost on oxidation and gained on reduction. Bacteriorhodopsin is a true proton pump. Light activation triggers trans to cis isomerization of a bound retinal. Strong electrostatic interactions within clusters of amino acids are modified by the conformational changes initiated by retinal motion leading to changes in proton affinity, driving transmembrane proton transfer. Cytochrome c oxidase (CcO) catalyzes the reduction of O2 to water. The protons needed for chemistry are bound from the N-side. The reduction chemistry also drives proton pumping from N- to P-side. Overall, in CcO the uptake of 4 electrons to reduce O2 transports 8 charges across the membrane, with each reduction fully coupled to removal of two protons from the N-side, the delivery of one for chemistry and transport of the other to the P-side. PMID:23507617

Tuning of acyl-ACP thioesterase activity directed for tailored fatty acid synthesis.

PubMed

Feng, Yanbin; Zhang, Yunxiu; Wang, Yayue; Liu, Jiao; Liu, Yinghui; Cao, Xupeng; Xue, Song

2018-04-01

Medium-chain fatty acids have attracted significant attention as sources of biofuels in recent years. Acyl-ACP thioesterase, which is considered as the key enzyme to determine the carbon chain length, catalyzes the termination of de novo fatty acid synthesis. Although recombinant medium-chain acyl-ACP thioesterase (TE) affects the fatty acid profile in heterologous cells, tailoring of the fatty acid composition merely by engineering a specific TE is still intractable. In this study, the activity of a C8-C10-specific thioesterase FatB2 from Cuphea hookeriana on C10-ACP was quantified twice as high as that on C8-ACP based on a synthetic C8-C16 acyl-ACP pool in vitro. Whereas in vivo, it was demonstrated that ChFatB2 preferred to accumulate C8 fatty acids with 84.9% composition in the ChFatB2-engineered E. coli strain. To achieve C10 fatty acid production, ChFatB2 was rationally tuned based on structural investigation and enzymatic analysis. An I198E mutant was identified to redistribute the C8-ACP flow, resulting in C10 fatty acid being produced as the principal component at 57.6% of total fatty acids in vivo. It was demonstrated that the activity of TE relative to β-ketoacyl-ACP synthases (KAS) directly determined the fatty acid composition. Our results provide a prospective strategy in tailoring fatty acid synthesis by tuning of TE activities based on TE-ACP interaction.

Assessing Colorectal Cancer Screening Behaviors and Knowledge among At-Risk Hispanics in Southern New Mexico*

PubMed Central

Sanchez, Janeth I.; Palacios, Rebecca; Thompson, Beti; Martinez, Vanessa; O’Connell, Mary A.

2014-01-01

Purpose Colorectal cancer (CRC) mortality rates in New Mexico (NM) continue to be higher than national rates. Hispanic CRC mortality rates in NM surpass those of overall Hispanics in the US. This study was designed to characterize and understand factors contributing to low CRC screening rates in this border region. Methods A CRC Knowledge Assessment Survey (KAS) was administered in either English or Spanish to 247 individuals attending community events throughout southern NM. A subset of these individuals completed an online CRC risk assessment survey managed by the National Cancer Institute (NCI). Data analysis tested for significant differences in knowledge, physician-patient CRC interactions, CRC risk level perception, and screening rates across diverse ethnic and age groups. Results Both CRC knowledge and physician-patient CRC interactions were positively associated with participant screening history. Significant age and ethnic differences for CRC knowledge, physician-patient CRC interactions, and screening history in the NM border sample were also seen. Age-eligible Hispanics (50+) as well as those less than 50 years of age had lower CRC knowledge and were less likely to engage in physician-patient CRC interactions than non-Hispanic Whites (NHWs). The age-eligible Hispanics also reported lower CRC screening rates than their NHW counterparts. Conclusions Low CRC knowledge and limited physician-patient CRC interactions appear to contribute to low screening rates in this NM population. Expanding education and outreach efforts for this border population are essential to promote early CRC detection and thereby decrease overall CRC mortality rates. PMID:25621179

Hemofagocitinė limfohistiocitozė: literatūros apžvalga

PubMed Central

Bereikienė, Simona; Rascon, Jelena

2017-01-01

Hemofagocitinė limfohistiocitozė – tai sindromas, besivystantis dėl sutrikusios imuninio atsako aktyvacijos ir slopinimo pusiausvyros. Išskiriama pirminė (genetinė arba šeiminė) sindromo forma, nulemta genų, dalyvaujančių imuninių ląstelių sąveikoje, mutacijų; ir antrinė (sporadinė) forma, besivystanti dėl infekcijos, navikinio, autoimuninio proceso ar metabolinių sutrikimų. Antrinės hemofagocitinės limfohistiocitozės genetinis pagrindas kol kas nežinomas. Pirminei ir antrinei formoms būdingas toks pats specifinis hiperuždegiminių reakcijų bei klinikinių simptomų kompleksas, kuriuo grindžiama patologijos diagnostika. Tačiau pirminės ir antrinės formų atskyrimas dažnai tampa iššūkiu dėl patologijos retumo, plataus klinikinių požymių spektro, dėl riboto specifinių testų prieinamumo ir, svarbiausia, gydymo taktikos ypatumų. Etiopatogenetinis pirminės formos gydymas yra skubi alogeninė kraujodaros kamieninių ląstelių transplantacija, be kurios išeitis neišvengiamai fatali. Antrinės formos gydymas priklauso nuo klinikinės išraiškos ir ją sukėlusios infekcijos pobūdžio. Labai svarbi laiku atlikta diagnostika norint kuo skubiau pradėti tinkamą gydymą bei pagerinti išgyvenamumą. Hemofagocitinės limfohistiocitozės gydymą komplikuoja didelis su gydymu susijęs mirtingumo dažnis bei ligos polinkis recidyvuoti. PMID:28630593

Spectroscopic study of 2-, 4- and 5-substituents on p Ka values of imidazole heterocycles prone to intramolecular proton-electrons transfer

NASA Astrophysics Data System (ADS)

Eseola, Abiodun O.; Obi-Egbedi, Nelson O.

2010-02-01

New 2-(1H-imidazol-2-yl)phenols ( L1Et- L8tBuPt) bearing a phenolic proton in the vicinity of the imidazole base were prepared and characterized. Experimental studies of the dependence of their protonation/deprotonation equilibrium on substituent identities and intramolecular hydrogen bonding tendencies were carried out using electronic absorption spectroscopy at varying pH values. In order to make comparison, 2-(anthracen-10-yl)-4,5-diphenyl-1H-imidazole ( L9Anthr) bearing no phenolic proton and 4,5-diphenyl-2-(4,5-diphenyl-1H-imidazol-2-yl)-1H-imidazole ( L10BisIm) bearing two symmetrical imidazole base fragments were also prepared and experimentally investigated. DFT calculations were carried out to study frontier orbitals of the investigated molecules. While electron-releasing substituents produced increase in protonation-deprotonation p Kas for the hydroxyl group, values for the imidazole base were mainly affected by polarization of the imidazole ring aromaticity across the 2-imidazole carbon and the 4,5-imidazole carbons axis of the imidazole ring. It was concluded that electron-releasing substituents on the phenol ring and/or electron-withdrawing substituents on 4,5-imidazole carbons negatively affects donor strengths/coordination chemistries of 2-(1H-imidazol-2-yl)phenols, and vice versa. Change of substituents on the phenol ring significantly altered the donor strength of the imidazole base. The understanding of p Ka variation on account of electronic effects of substituents in this work should aid the understanding of biochemical properties and substituent environments of imidazole-containing biomacromolecules.

Analytical Treatment of Forecasts of Electric Energy Consumption in Latvia

NASA Astrophysics Data System (ADS)

Balodis, M.; Gavars, V.; Andersons, J.

2014-06-01

In the paper, the changes in electric energy consumption are analyzed as associated with structural changes in the Latvian economy of postsocialistic period. To the analysis, a particular approach is applied, which consists in comparison of the basic and specific electricity consumption indices in West-, Central-, and East-European states for the time span of 1990-2010, with differences and tendencies of changes revealed. Tendencies of the type are determined for the electric energy consumption in Latvia, and recommendations are given for the use of such indices in the relevant forecasts. Rakstā apskatītas elektroenerģijas patēriņa izmaiņas, kas saistītas ar Latvijas postsociālisma perioda ekonomikas strukturālām izmaiņām. Rakstā dota Latvijas galveno elektroenerģijas patēriņa indikatoru analīze, lietojot īpašu pieeju - Rietumeiropas, Centrāleiropas un Austrumeiropas valstu indikatoru salīdzinājumu. Analizēts periods no 1990. gada līdz 2010. gadam. Salīdzināti Eiropas valstu grupu īpatnējie elektroenerģijas patēriņa indikatori un noskaidrotas to atšķirības un izmaiņu tendences. Noteiktas elektroenerģijas patēriņa izmaiņu tendences Latvijā. Dotas rekomendācijas par šo indikatoru izmantošanu elektroenerģijas patēriņa prognozēšanā. 07.05.2014.

Computational investigation of kinetics of cross-linking reactions in proteins: importance in structure prediction.

PubMed

Bandyopadhyay, Pradipta; Kuntz, Irwin D

2009-01-01

The determination of protein structure using distance constraints is a new and promising field of study. One implementation involves attaching residues of a protein using a cross-linking agent, followed by protease digestion, analysis of the resulting peptides by mass spectroscopy, and finally sequence threading to detect the protein folds. In the present work, we carry out computational modeling of the kinetics of cross-linking reactions in proteins using the master equation approach. The rate constants of the cross-linking reactions are estimated using the pKas and the solvent-accessible surface areas of the residues involved. This model is tested with fibroblast growth factor (FGF) and cytochrome C. It is consistent with the initial experimental rate data for individual lysine residues for cytochrome C. Our model captures all observed cross-links for FGF and almost 90% of the observed cross-links for cytochrome C, although it also predicts cross-links that were not observed experimentally (false positives). However, the analysis of the false positive results is complicated by the fact that experimental detection of cross-links can be difficult and may depend on specific experimental conditions such as pH, ionic strength. Receiver operator characteristic plots showed that our model does a good job in predicting the observed cross-links. Molecular dynamics simulations showed that for cytochrome C, in general, the two lysines come closer for the observed cross-links as compared to the false positive ones. For FGF, no such clear pattern exists. The kinetic model and MD simulation can be used to study proposed cross-linking protocols.

Heterologous production of kasugamycin, an aminoglycoside antibiotic from Streptomyces kasugaensis, in Streptomyces lividans and Rhodococcus erythropolis L-88 by constitutive expression of the biosynthetic gene cluster.

PubMed

Kasuga, Kano; Sasaki, Akira; Matsuo, Takashi; Yamamoto, Chika; Minato, Yuiko; Kuwahara, Naoya; Fujii, Chikako; Kobayashi, Masayuki; Agematu, Hitosi; Tamura, Tomohiro; Komatsu, Mamoru; Ishikawa, Jun; Ikeda, Haruo; Kojima, Ikuo

2017-05-01

Kasugamycin (KSM), an aminoglycoside antibiotic isolated from Streptomyces kasugaensis cultures, has been used against rice blast disease for more than 50 years. We cloned the KSM biosynthetic gene (KBG) cluster from S. kasugaensis MB273-C4 and constructed three KBG cassettes (i.e., cassettes I-III) to enable heterologous production of KSM in many actinomycetes by constitutive expression of KBGs. Cassette I comprised all putative transcriptional units in the cluster, but it was placed under the control of the P neo promoter from Tn5. It was not maintained stably in Streptomyces lividans and did not transform Rhodococcus erythropolis. Cassette II retained the original arrangement of KBGs, except that the promoter of kasT, the specific activator gene for KBG, was replaced with P rpsJ , the constitutive promoter of rpsJ from Streptomyces avermitilis. To enhance the intracellular concentration of myo-inositol, an expression cassette of ino1 encoding the inositol-1-phosphate synthase from S. avermitilis was inserted into cassette II to generate cassette III. These two cassettes showed stable maintenance in S. lividans and R. erythropolis to produce KSM. Particularly, the transformants of S. lividans induced KSM production up to the same levels as those produced by S. kasugaensis. Furthermore, cassette III induced more KSM accumulation than cassette II in R. erythropolis, suggesting an exogenous supply of myo-inositol by the ino1 expression in the host. Cassettes II and III appear to be useful for heterologous KSM production in actinomycetes. Rhodococcus exhibiting a spherical form in liquid cultivation is also a promising heterologous host for antibiotic fermentation.

Electric Machines with Non-Radially Mounted Rectangular Permanent Magnets / Elektriskās Mašīnas Ar Prizmatiskiem Neradiāli Novietotiem Pastāvīgajiem Magnētiem

NASA Astrophysics Data System (ADS)

Levin, N.; Pugachev, V.; Dirba, J.; Lavrinovicha, L.

2013-04-01

The authors analyze the advantages and disadvantages of brushless synchronous electric machines with radially and non-radially mounted rectangular permanent magnets. The results show that the proposed nonradial mounting of permanent magnets considered in the paper, in several cases (e.g. multi-pole brushless generators with tooth windings of the armature) allows achievement of the following advantages: better technology of manufacturing the electric machine owing to simple packing of the stator winding in the stator open slots, which also increases the copper slot fillfactor; reduction in the mass-and-size of permanent magnets at least twice; significantly lower cost of the electric machine; and, finally, its greater specific power. Darbā tiek analizētas priekšrocības un trūkumi sinhronām bezkontaktu mašīnām ar radiāli un neradiāli novietotiem prizmatiskiem pastāvīgajiem magnētiem. Parādīts, ka vairākos gadījumos, piemēram, daudzpolu bezkontaktu sinhronajos ģeneratoros ar zobu tinumiem, neradiāls pastāvīgo magnētu izvietojums nodrošina vairākas priekšrocības: uzlabojas mašīnas izgatavošanas tehnoloģija, jo statora atvērtajās rievās vieglāk novietot tinumus un iespējams sasniegt augstāku rievas aizpildījuma koeficientu; samazinās pastāvīgo magnētu masa un izmaksas; palielinās mašīnas īpatnēja jauda.

Inactivation of the inhA-Encoded Fatty Acid Synthase II (FASII) Enoyl-Acyl Carrier Protein Reductase Induces Accumulation of the FASI End Products and Cell Lysis of Mycobacterium smegmatis

PubMed Central

Vilchèze, Catherine; Morbidoni, Hector R.; Weisbrod, Torin R.; Iwamoto, Hiroyuki; Kuo, Mack; Sacchettini, James C.; Jacobs, William R.

2000-01-01

The mechanism of action of isoniazid (INH), a first-line antituberculosis drug, is complex, as mutations in at least five different genes (katG, inhA, ahpC, kasA, and ndh) have been found to correlate with isoniazid resistance. Despite this complexity, a preponderance of evidence implicates inhA, which codes for an enoyl-acyl carrier protein reductase of the fatty acid synthase II (FASII), as the primary target of INH. However, INH treatment of Mycobacterium tuberculosis causes the accumulation of hexacosanoic acid (C26:0), a result unexpected for the blocking of an enoyl-reductase. To test whether inactivation of InhA is identical to INH treatment of mycobacteria, we isolated a temperature-sensitive mutation in the inhA gene of Mycobacterium smegmatis that rendered InhA inactive at 42°C. Thermal inactivation of InhA in M. smegmatis resulted in the inhibition of mycolic acid biosynthesis, a decrease in hexadecanoic acid (C16:0) and a concomitant increase of tetracosanoic acid (C24:0) in a manner equivalent to that seen in INH-treated cells. Similarly, INH treatment of Mycobacterium bovis BCG caused an inhibition of mycolic acid biosynthesis, a decrease in C16:0, and a concomitant accumulation of C26:0. Moreover, the InhA-inactivated cells, like INH-treated cells, underwent a drastic morphological change, leading to cell lysis. These data show that InhA inactivation, alone, is sufficient to induce the accumulation of saturated fatty acids, cell wall alterations, and cell lysis and are consistent with InhA being a primary target of INH. PMID:10869086

WAX INDUCER1 (HvWIN1) transcription factor regulates free fatty acid biosynthetic genes to reinforce cuticle to resist Fusarium head blight in barley spikelets

PubMed Central

Kumar, Arun; Yogendra, Kalenahalli N.; Karre, Shailesh; Kushalappa, Ajjamada C.; Dion, Yves; Choo, Thin M.

2016-01-01

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most devastating diseases of wheat and barley. Resistance to FHB is highly complex and quantitative in nature, and is most often classified as resistance to spikelet infection and resistance to spread of pathogen through the rachis. In the present study, a resistant (CI9831) and a susceptible (H106-371) two-row barley genotypes, with contrasting levels of spikelet resistance to FHB, pathogen or mock-inoculated, were profiled for metabolites based on liquid chromatography and high resolution mass spectrometry. The key resistance-related (RR) metabolites belonging to fatty acids, phenylpropanoids, flavonoids and terpenoid biosynthetic pathways were identified. The free fatty acids (FFAs) linoleic and palmitic acids were among the highest fold change RR induced (RRI) metabolites. These FFAs are deposited as cutin monomers and oligomers to reinforce the cuticle, which acts as a barrier to pathogen entry. Quantitative real-time PCR studies revealed higher expressions of KAS2, CYP86A2, CYP89A2, LACS2 and WAX INDUCER1 (HvWIN1) transcription factor in the pathogen-inoculated resistant genotype than in the susceptible genotype. Knockdown of HvWIN1 by virus-induced genes silencing (VIGS) in resistant genotype upon pathogen inoculation increased the disease severity and fungal biomass, and decreased the abundance of FFAs like linoleic and palmitic acids. Notably, the expression of CYP86A2, CYP89A2 and LAC2 genes was also suppressed, proving the link of HvWIN1 in regulating these genes in cuticle biosynthesis as a defense response. PMID:27194736

Bohr effect of hemoglobins: Accounting for differences in magnitude.

PubMed

Okonjo, Kehinde O

2015-09-07

The basis of the difference in the Bohr effect of various hemoglobins has remained enigmatic for decades. Fourteen amino acid residues, identical in pairs and located at specific 'Bohr group positions' in human hemoglobin, are implicated in the Bohr effect. All 14 are present in mouse, 11 in dog, eight in pigeon and 13 in guinea pig hemoglobin. The Bohr data for human and mouse hemoglobin are identical: the 14 Bohr groups appear at identical positions in both molecules. The dog data are different from the human because three Bohr group positions are occupied by non-ionizable groups in dog hemoglobin; the pigeon data are vastly different from the human because six Bohr group positions are occupied by non-ionizable groups in pigeon hemoglobin. The guinea pig data are quite complex. Quantitative analyses showed that only the pigeon data could be fitted with the Wyman equation for the Bohr effect. We demonstrate that, apart from guinea pig hemoglobin, the difference between the Bohr effect of each of the other hemoglobins and of pigeon hemoglobin can be accounted for quantitatively on the basis of the occupation of some of their Bohr group positions by non-ionizable groups in pigeon hemoglobin. We attribute the anomalous guinea pig result to a new salt-bridge formed in its R2 quaternary structure between the terminal NH3(+) group of one β-chain and the COO(-) terminal group of the partner β-chain in the same molecule. The pKas of this NH3(+) group are 6.33 in the R2 and 4.59 in the T state. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rosette iron deficiency transcript and microRNA profiling reveals links between copper and iron homeostasis in Arabidopsis thaliana

PubMed Central

Waters, Brian M.; Stein, Ricardo J.

2012-01-01

Iron (Fe) is an essential plant micronutrient, and its deficiency limits plant growth and development on alkaline soils. Under Fe deficiency, plant responses include up-regulation of genes involved in Fe uptake from the soil. However, little is known about shoot responses to Fe deficiency. Using microarrays to probe gene expression in Kas-1 and Tsu-1 ecotypes of Arabidopsis thaliana, and comparison with existing Col-0 data, revealed conserved rosette gene expression responses to Fe deficiency. Fe-regulated genes included known metal homeostasis-related genes, and a number of genes of unknown function. Several genes responded to Fe deficiency in both roots and rosettes. Fe deficiency led to up-regulation of Cu,Zn superoxide dismutase (SOD) genes CSD1 and CSD2, and down-regulation of FeSOD genes FSD1 and FSD2. Eight microRNAs were found to respond to Fe deficiency. Three of these (miR397a, miR398a, and miR398b/c) are known to regulate transcripts of Cu-containing proteins, and were down-regulated by Fe deficiency, suggesting that they could be involved in plant adaptation to Fe limitation. Indeed, Fe deficiency led to accumulation of Cu in rosettes, prior to any detectable decrease in Fe concentration. ccs1 mutants that lack functional Cu,ZnSOD proteins were prone to greater oxidative stress under Fe deficiency, indicating that increased Cu concentration under Fe limitation has an important role in oxidative stress prevention. The present results show that Cu accumulation, microRNA regulation, and associated differential expression of Fe and CuSOD genes are coordinated responses to Fe limitation. PMID:22962679

Loss of compatibility might explain resistance of the Arabidopsis thaliana accession Te-0 to Golovinomyces cichoracearum.

PubMed

Fabro, Georgina; Alvarez, María Elena

2012-08-11

The establishment of compatibility between plants and pathogens requires compliance with various conditions, such as recognition of the right host, suppression of defence mechanisms, and maintenance of an environment allowing pathogen reproduction. To date, most of the plant factors required to sustain compatibility remain unknown, with the few best characterized being those interfering with defence responses. A suitable system to study host compatibility factors is the interaction between Arabidopsis thaliana and the powdery mildew (PM) Golovinomyces cichoracearum. As an obligate biotrophic pathogen, this fungus must establish compatibility in order to perpetuate. In turn, A. thaliana displays natural variation for susceptibility to this invader, with some accessions showing full susceptibility (Col-0), and others monogenic dominant resistance (Kas-1). Interestingly, Te-0, among other accessions, displays recessive partial resistance to this PM. In this study, we characterized the interaction of G. cichoracearum with Te-0 plants to investigate the basis of this plant resistance. We found that Te-0's incompatibility was not associated with hyper-activation of host inducible defences. Te-0 plants allowed germination of conidia and development of functional haustoria, but could not support the formation of mature conidiophores. Using a suppressive subtractive hybridization technique, we identified plant genes showing differential expression between resistant Te-0 and susceptible Col-0 plants at the fungal pre-conidiation stage. Te-0 resistance is likely caused by loss of host compatibility and not by stimulation of inducible defences. Conidiophores formation is the main constraint for completion of fungal life cycle in Te-0 plants. The system here described allowed the identification of genes proposed as markers for susceptibility to this PM.

Uncovering Specific Electrostatic Interactions in the Denatured States of Proteins

PubMed Central

Shen, Jana K.

2010-01-01

The stability and folding of proteins are modulated by energetically significant interactions in the denatured state that is in equilibrium with the native state. These interactions remain largely invisible to current experimental techniques, however, due to the sparse population and conformational heterogeneity of the denatured-state ensemble under folding conditions. Molecular dynamics simulations using physics-based force fields can in principle offer atomistic details of the denatured state. However, practical applications are plagued with the lack of rigorous means to validate microscopic information and deficiencies in force fields and solvent models. This study presents a method based on coupled titration and molecular dynamics sampling of the denatured state starting from the extended sequence under native conditions. The resulting denatured-state pKas allow for the prediction of experimental observables such as pH- and mutation-induced stability changes. I show the capability and use of the method by investigating the electrostatic interactions in the denatured states of wild-type and K12M mutant of NTL9 protein. This study shows that the major errors in electrostatics can be identified by validating the titration properties of the fragment peptides derived from the sequence of the intact protein. Consistent with experimental evidence, our simulations show a significantly depressed pKa for Asp8 in the denatured state of wild-type, which is due to a nonnative interaction between Asp8 and Lys12. Interestingly, the simulation also shows a nonnative interaction between Asp8 and Glu48 in the denatured state of the mutant. I believe the presented method is general and can be applied to extract and validate microscopic electrostatics of the entire folding energy landscape. PMID:20682271

Loss of compatibility might explain resistance of the Arabidopsis thaliana accession Te-0 to Golovinomyces cichoracearum

PubMed Central

2012-01-01

Background The establishment of compatibility between plants and pathogens requires compliance with various conditions, such as recognition of the right host, suppression of defence mechanisms, and maintenance of an environment allowing pathogen reproduction. To date, most of the plant factors required to sustain compatibility remain unknown, with the few best characterized being those interfering with defence responses. A suitable system to study host compatibility factors is the interaction between Arabidopsis thaliana and the powdery mildew (PM) Golovinomyces cichoracearum. As an obligate biotrophic pathogen, this fungus must establish compatibility in order to perpetuate. In turn, A. thaliana displays natural variation for susceptibility to this invader, with some accessions showing full susceptibility (Col-0), and others monogenic dominant resistance (Kas-1). Interestingly, Te-0, among other accessions, displays recessive partial resistance to this PM. Results In this study, we characterized the interaction of G. cichoracearum with Te-0 plants to investigate the basis of this plant resistance. We found that Te-0´s incompatibility was not associated with hyper-activation of host inducible defences. Te-0 plants allowed germination of conidia and development of functional haustoria, but could not support the formation of mature conidiophores. Using a suppressive subtractive hybridization technique, we identified plant genes showing differential expression between resistant Te-0 and susceptible Col-0 plants at the fungal pre-conidiation stage. Conclusions Te-0 resistance is likely caused by loss of host compatibility and not by stimulation of inducible defences. Conidiophores formation is the main constraint for completion of fungal life cycle in Te-0 plants. The system here described allowed the identification of genes proposed as markers for susceptibility to this PM. PMID:22883024

Development and Experimental Study of Phantoms for Mapping Skin Chromophores

NASA Astrophysics Data System (ADS)

Silapetere, A.; Spigulis, J.; Saknite, I.

2014-06-01

Skin chromophore phantoms are widely used for better understanding of the light interaction with tissue and for calibration of skin diagnostic imaging techniques. In this work, different phantoms were examined and compared in order to find biologically equivalent substances that are the most promising for this purpose. For mimicking the skin medium and layered structure, a fibrin matrix with epidermal and dermal cell inclusion was used. Synthesized bilirubin, red blood cells and nigrosin were taken as absorbers. For spectral analysis of the developed phantoms a computer-aided multispectral imaging system Nuance 2.4 (Cambridge Research & Instrumentation, Inc., USA) was used. In this study, skin phantoms were created using such substances as bilirubin, melanin, haemoglobin and nigrosin Mūsdienās multispektrālās attēlošanas iekārtas izmanto ādas parametru un fizioloģisko procesu aprakstīšanai gan pētniecības, gan diagnostikas nolūkiem. Iekārtu darbības uzlabošanai ir nepieciešams labāk saprast gaismas mijiedarbību ar audiem, kā arī veikt šo iekārtu kalibrēšanu ar ādas maketu. Redzamā un tuvā infrasarkanā optiskā diapazona spektroskopijā ir svarīgi ādas maketi, kas simulē audu slāņaino struktūru un ķīmiskās īpašības, kā arī maketi, kas ir bioloģiski līdzvērtīgi. Šajā pētījumā tika izveidots ādas makets no bioloģiskām un ķīmiski sintezētām struktūrām. Ādas maketa izveidei tika izmantota fibrīna matrica ar dermālo un epidermālo šūnu piejaukumu, lai imitētu ādas slāņaino struktūru. Fibrīna matrica tiek veidota no 0,47 ml asins plazmas, 0,4 ml fizioloģiskā šķīduma, 0,8 μl treneksāmskābes un 89,4 μl kalcija glukanāta. Izveidoto matricu ievieto šūnu inkubatorā, lai tā polimerizētos. Nākošais slānis tiek veidots ar dermālo šūnu piejaukumu (180-270 šūnas), un pēdējais fibrīna matriksa slānis tiek veidots ar epidermālo šūnu piejaukumu (270 šūnas) un šūnu aug

Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens

PubMed Central

Kleiveland, Charlotte R.; Minic, Rajna; Moen, Lars F.; Øverland, Lise; Tjåland, Rannei; Carlsen, Harald; Lea, Tor; Eijsink, Vincent G. H.

2016-01-01

ABSTRACT Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum. The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo. The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. IMPORTANCE This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and

Utility of Th1-cell immune responses for distinguishing active tuberculosis from non-active tuberculosis: A case-control study

PubMed Central

Zhang, Lifan; Cheng, Xinhe; Bian, Sainan; Song, Yanhua; Li, Qiang; Gao, Mengqiu; Zhang, Yueqiu; Shi, Xiaochun

2017-01-01

Currently available Interferon-γ release assay (IGRA) cannot reliably differentiate active TB (ATB) from non-active TB (non-ATB). A study was performed to evaluate the value of Mycobacterium tuberculosis (MTB) specific Th1 cell immune responses which test IFN-γ and IL-2 simultaneous for differentiating ATB from non-ATB. Forty-nine newly diagnosed inpatients with ATB (26 pulmonary TB and 23 extrapulmonary TB) were enrolled as the ATB group. Forty-five volunteers with latent tuberculosis infection (LTBI) and twenty with evidence of previous TB were enrolled during the same period as the non-ATB group. Clinical examination and MTB specific Th1 cell immune responses were performed for all participants. After being stimulated with ESAT-6 and CFP-10, the median frequencies of single IL-2-, single IFN-γ-, and dual IFN-γ/IL-2-secreting T-cells were all higher in the ATB group than in the non-ATB group (20(8–45) vs. 7(3–13), P<0.001;131(44–308) vs. 10(6–27), P<0.001;25(9–74) vs. 7(3–23), P = 0.001, respectively). Evaluation of the diagnostic performance of detecting single IFN-γ-secreting T cells for pulmonary TB employed a cutoff value of 35 iSFCs/250,000 PBMC. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were 92.3%, 80.0%, 64.9%, 96.3%, 4.62, and 0.10, respectively. For extrapulmonary TB, using a cutoff value of 23 iSFCs/ 250,000 PBMC, the sensitivity, specificity, PPV, NPV, PLR, and NLR were 91.3%, 76.9%, 58.3%, 96.2%, 3.96, and 0.11, respectively. When combining frequencies and proportion of single IFN-γ-secreting T cells, the test sensitivity was 100% in parallel tests and the specificity was 87.7% in serial tests for pulmonary TB. MTB specific Th1 cell immune responses (FluoroSpot) had value for the differentiation of ATB and non-ATB. Further confirmatory studies are indicated. PMID:28531231

The elephant interferon gamma assay: a contribution to diagnosis of tuberculosis in elephants.

PubMed

Angkawanish, T; Morar, D; van Kooten, P; Bontekoning, I; Schreuder, J; Maas, M; Wajjwalku, W; Sirimalaisuwan, A; Michel, A; Tijhaar, E; Rutten, V

2013-11-01

Mycobacterium tuberculosis (M. tb) has been shown to be the main causative agent of tuberculosis in elephants worldwide. M. tb may be transmitted from infected humans to other species including elephants and vice versa, in case of prolonged intensive contact. An accurate diagnostic approach covering all phases of the infection in elephants is required. As M. tb is an intracellular pathogen and cell-mediated immune (CMI) responses are elicited early after infection, the skin test is the CMI assay of choice in humans and cattle. However, this test is not applicable in elephants. The interferon gamma (IFN-γ) assay is considered a good alternative for the skin test in general, validated for use in cattle and humans. This study was aimed at development of an IFN-γ assay applicable for diagnosis of tuberculosis in elephants. Recombinant elephant IFN-γ (rEpIFN-γ) produced in eukaryotic cells was used to immunize mice and generate the monoclonal antibodies. Hybridomas were screened for IFN-γ-specific monoclonal antibody production and subcloned, and antibodies were isotyped and affinity purified. Western blot confirmed recognition of the rEpIFN-γ. The optimal combination of capture and detection antibodies selected was able to detect rEpIFN-γ in concentrations as low as 1 pg/ml. The assay was shown to be able to detect the native elephant IFN-γ, elicited in positive-control cultures (pokeweed mitogen (PWM), phorbol myristate acetate plus ionomycin (PMA/I)) of both Asian and African elephant whole-blood cultures (WBC). Preliminary data were generated using WBC from non-infected elephants, a M. tb infection-suspected elephant and a culture-confirmed M. tb-infected elephant. The latter showed measurable production of IFN-γ after stimulation with ESAT6/CFP10 PPDB and PPDA in concentration ranges as elicited in WBC by Mycobacterium tuberculosis complex (MTBC)-specific antigens in other species. Hence, the IFN-γ assay presented potential as a diagnostic tool for the

Analysis of transcription factors, microRNAs and cytokines involved in T lymphocyte differentiation in patients with tuberculosis after directly observed treatment short-course.

PubMed

Corral-Fernández, Nancy Elizabeth; Cortes-García, Juan Diego; Bruno, Rivas-Santiago; Romano-Moreno, Silvia; Medellín-Garibay, Susanna E; Magaña-Aquino, Martín; Salazar-González, Raúl A; González-Amaro, Roberto; Portales-Pérez, Diana Patricia

2017-07-01

Tuberculosis (Tb) is an infectious disease in which the immune system plays an important role. MicroRNAs are involved in the development and maintenance of CD4 + T lymphocyte subpopulations. miR-326 regulates the differentiation to Th17 cells and miR-29 correlates with the Th1 response. The aim of this study was to determine the role of microRNAs, Transcription Factors, and cytokines in Th differentiation before and after the directly observed treatment short-course (DOTS). Peripheral blood mononuclear cells and serum from Tb patients were collected at times 0 (before therapy), 2 (after the intensive phase), and 6 months (after the holding phase). The cells were cultivated in presence or absence of ESAT-6 (10 μg/ml) and CFP-10 (10 μg/ml). Transcription Factor and microRNA expressions were analyzed by qPCR and cytokine production in both serum and culture supernatant using ELISA. A decrease in Th1 response with a diminishing in the relative expression of TBET and miR-29a at 2 and 6 months after the anti-Tb therapy (p < 0.01) were found. The miR-326 levels decreased after the intensive phase of the DOTS scheme. However, subdivision of the Tb patients according to gender, showed increased levels of miR-29a and miR-155 in females after the intensive phase of the therapeutic treatment when compared to time 0 and similar increased levels of miR-326 at time 6 versus time 0. In contrast, we observed a decrease in miR-326 levels in males at 6 months when compared to before therapy (time 0). In addition, high production of IL-17 in the culture supernatant was found at 2 and 6 months (p < 0.05) while in serum IL-17 was decreased. A positive correlation between IL-17 and RORC2 at time 6 was detected (p = 0.0202, r = 0.7880). In conclusion, these data suggest a reduction in Th1 and an induction of Th17 response after the anti-Tb therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens.

PubMed

Kuczkowska, Katarzyna; Kleiveland, Charlotte R; Minic, Rajna; Moen, Lars F; Øverland, Lise; Tjåland, Rannei; Carlsen, Harald; Lea, Tor; Mathiesen, Geir; Eijsink, Vincent G H

2017-01-15

Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and to anchor this

Identification of new diagnostic biomarkers for Mycobacterium tuberculosis and the potential application in the serodiagnosis of human tuberculosis.

PubMed

Ren, Ningning; JinLi, Jingfang; Chen, Yingyu; Zhou, Xia; Wang, Jieru; Ge, Pan; Khan, Farhan Anwar; Zhang, Li; Hu, Changmin; Robertson, Ian D; Chen, Huanchun; Guo, Aizhen

2018-06-27

Mycobacterium tuberculosis (M. tuberculosis) regions of difference (RD) encode proteins which are potentially useful as diagnostic reagents for tuberculosis (TB). In this study, 75 genes from M. tuberculosis RD1-RD16 were successfully cloned from which 68 proteins were expressed and purified. Three serum pools from patients with pulmonary TB (PTB), extra-pulmonary tuberculosis (EPTB) and healthy controls (HC) were used to preliminarily screen individual RD proteins. The OD 630 ratio of the PTB or EPTB to the HC group ≥ 2-fold was positive. As a result, 29 proteins were obtained. The serological response to the identified antigens was further verified using 58 PTB samples with 38 sera from smear-positive PTB (PTB-SP) patients and 20 sera from smear-negative PTB (PTB-SN) patients, 16 EPTB samples, 42 latent M. tuberculosis infection samples and 40 HCs by indirect ELISA. With respect to the PTB diagnosis, receiver operating characteristic analysis showed that Rv0222 [area under the curve (AUC), 0.8129; 95% confidence interval (CI), 0.7280-0.8979] and Rv3403c (AUC, 0.8537; 95% CI, 0.7779-0.9294) performed better than ESAT6/CFP10 (AUC, 0.7435; 95% CI, 0.6465-0.8406). Rv0222 and Rv3403c demonstrated the highest diagnostic ability in the PTB-SP group (sensitivity, 86.8%; specificity, 80%), while Rv3403c demonstrated the highest diagnostic ability in the PTB-SN group (sensitivity, 70%; specificity, 80%). With respect to the EPTB diagnosis, Rv0222 exhibited the highest diagnostic value (AUC, 0.7523; sensitivity, 68.8%; specificity, 87.5%). In addition, the combination of Rv0222 and Rv3403c improved the test for PTB-SN. These results indicate that Rv0222 and Rv3403c would be potential diagnostic biomarkers for active TB serodiagnosis. Mouse experiments demonstrated that Rv0222 and Rv3403c elicited specific cellular and humoral responses which were characterized by production of IFN-γ, IgG1, and IgG2a, but a higher level of IgG1 than IgG2a. © 2018 The Authors

Immunological and physical evaluation of the multistage tuberculosis subunit vaccine candidate H56/CAF01 formulated as a spray-dried powder.

PubMed

Thakur, Aneesh; Ingvarsson, Pall Thor; Schmidt, Signe Tandrup; Rose, Fabrice; Andersen, Peter; Christensen, Dennis; Foged, Camilla

2018-05-31

Liquid vaccine dosage forms have limited stability and require refrigeration during their manufacture, distribution and storage. In contrast, solid vaccine dosage forms, produced by for example spray drying, offer improved storage stability and reduced dependence on cold-chain facilities. This is advantageous for mass immunization campaigns for global public health threats, e.g., tuberculosis (TB), and offers cheaper vaccine distribution. The multistage subunit vaccine antigen H56, which is a fusion protein of the Mycobacterium tuberculosis (Mtb) antigens Ag85B, ESAT-6, and Rv2660, has been shown to confer protective efficacy against active TB before and after Mtb exposure in preclinical models, and it is currently undergoing clinical phase 2a testing. In several studies, including a recent study comparing multiple clinically relevant vaccine adjuvants, the T helper type 1 (Th1)/Th17-inducing adjuvant CAF01 was the most efficacious adjuvant for H56 to stimulate protective immunity against Mtb. With the long-term goal of designing a thermostable and self-administrable dry powder vaccine based on H56 and CAF01 for inhalation, we compared H56 spray-dried with CAF01 with the non-spray-dried H56/CAF01 vaccine with respect to their ability to induce systemic Th1, Th17 and humoral responses after subcutaneous immunization. Here we show that spray drying of the H56/CAF01 vaccine results in preserved antigenic epitope recognition and adjuvant activity of CAF01, and the spray-dried, reconstituted vaccine induces antigen-specific Th1, Th17 and humoral immune responses, which are comparable to those stimulated by the non-spray-dried H56/CAF01 vaccine. In addition, the spray-dried and reconstituted H56/CAF01 vaccine promotes similar polyfunctional CD4 + T-cell responses as the non-spray-dried vaccine. Thus, our study provides proof-of-concept that spray drying of the subunit vaccine H56/CAF01 preserves vaccine-induced humoral and cell-mediated immune responses. These results

Cine-servo lens technology for 4K broadcast and cinematography

NASA Astrophysics Data System (ADS)

Nurishi, Ryuji; Wakazono, Tsuyoshi; Usui, Fumiaki

2015-09-01

Central to the rapid evolution of 4K image capture technology in the past few years, deployment of large-format cameras with Super35mm Single Sensors is increasing in TV production for diverse shows such as dramas, documentaries, wildlife, and sports. While large format image capture has been the standard in the cinema world for quite some time, the recent experiences within the broadcast industry have revealed a variety of requirement differences for large format lenses compared to those of the cinema industry. A typical requirement for a broadcast lens is a considerably higher zoom ratio in order to avoid changing lenses in the middle of a live event, which is mostly not the case for traditional cinema productions. Another example is the need for compact size, light weight, and servo operability for a single camera operator shooting in a shoulder-mount ENG style. On the other hand, there are new requirements that are common to both worlds, such as smooth and seamless change in angle of view throughout the long zoom range, which potentially offers new image expression that never existed in the past. This paper will discuss the requirements from the two industries of cinema and broadcast, while at the same time introducing the new technologies and new optical design concepts applied to our latest "CINE-SERVO" lens series which presently consists of two models, CN7x17KAS-S and CN20x50IAS-H. It will further explain how Canon has realized 4K optical performance and fast servo control while simultaneously achieving compact size, light weight and high zoom ratio, by referring to patent-pending technologies such as the optical power layout, lens construction, and glass material combinations.

Lietuvos erdvinės informacijos sklaidos galimybės ir perspektyvos

NASA Astrophysics Data System (ADS)

Beconytė, Giedrė; Papšienė, Lina; Kryžanauskas, Audrius

2010-01-01

Padidėjęs erdvinių duomenų ir jų naudojimo poreikis paskatino kurti erdvinių duomenų infrastruktūras, leidžiančias teikti erdvinius duomenis aprašančią informaciją bei pačius duomenis iš įvairių šaltinių, nepriklausomai kur jie bebūtų bei duomenų formato ar struktūros. Lietuvoje dauguma erdvinių duomenų rinkinių "izoliuoti", o informacija apie juos sunkiai prieinama, todėl buvo siekiama sukurti modernią visą šalį apimančią vieną viešojo sektoriaus erdvinių duomenų paie\\vskos ir perdavimo sistemą. 2009 m. buvo sukurta Lietuvos erdvinės informacijos infrastruktūra (LEII), suteikianti priemones užtikrinti nacionalinių erdvinių duomenų pasiekiamumą ir teikimą internetu naudotojams jiems priimtinu būdu. Pagrindinis Europos Bendrijos erdvinės informacijos infrastruktūros (INSPIRE) kūrimo tikslas - pasiekti visų Bendrijos narių erdvinės informacijos suderinamumą. Įvairiose šalyse duomenų kaupimo, tvarkymo ir teikimo praktika skirtinga, todėl yra kuriamos bendros, vienijančios INSPIRE temų erdvinių duomenų rinkinių specifikacijos. Europos Bendrijos narės bus įpareigotos teikti duomenis INSPIRE laikantis šių specifkacijų, todėl atsiras galimybė iš skirtingų Europos Bendrijos valstybių gautus erdvinius duomenis sujungti ir naudoti kaip bendrus. Sukūrus LEII, Lietuvoje technologi\\vskai pasirengta teikti erdvinius duomenis bei yra sukaupti 56 oficialių duomenų rinkiniai, atitinkantys INSPIRE temas. Nors kol kas visi duomenų rinkiniai ne visi\\vskai atitinka patvirtintąsias specifikacijas, taikant Lietuvos erdvinės informacijos infrastruktūros technologijas, duomenis galima transformuoti į reikiamą struktūrą teikimo proceso metu.

Thermal degradation of paper industry wastes from a recovered paper mill using TGA. Characterization and gasification test.

PubMed

Arenales Rivera, Jorge; Pérez López, Virginia; Ramos Casado, Raquel; Sánchez Hervás, José-María

2016-01-01

In this survey, a refuse derived fuel (RDF) was produced from paper industry wastes through a mechanical treatment (MT). The two main wastes generated from a recovered paper mill were rejects and de-inking sludge, which were produced principally in the pulping and de-inking processes, respectively. This work presents raw wastes characterization, fuel preparation and gasification tests performed in a circulating fluidized bed (CFB) gasifier pilot plant. The characterization was carried out by proximate and ultimate analysis. Several blends of pre-conditioned rejects and de-inking sludge were densified by means of pelletizing, studying the energy consumption and its quality properties. Besides, thermal degradation of blends was studied under thermogravimetric analysis (TGA). The experimental runs were made from 30 to 900°C in nitrogen atmosphere at three heating ranges, β=5, 10 and 20°C/min. Two thermal stages were identified during the thermal degradation, which are linked to cellulose and plastic degradation. In addition, kinetics parameters were estimated by the application of non-isothermal methods: Kissinger-Akahira-Sunose (KAS), Flynn-Ozawa-Wall (FOW) and Coats and Redfern. The activation energy values were about 140-160 kJ/mol and 60-80 kJ/mol for plastic and cellulosic materials, respectively. Regarding waste valorisation, a blend composed of 95% of rejects and 5% of de-inking sludge was selected for gasification tests. The energy consumption during the preparation was recorded and a gasification tests were done to prove the usability of these pellets in a CFB gasifier. The main results were a net calorific value (NCV) of 5 MJ/Nm(3) and a total tar content of 11.44 g/Nm(3) at an equivalence ratio (ER) of 0.3. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differences in Organizational Structure of Insulin Receptor on Rat Adipocyte and Liver Plasma Membranes: Role of Disulfide Bonds

NASA Astrophysics Data System (ADS)

Schweitzer, John B.; Smith, Robert M.; Jarett, Leonard

1980-08-01

Binding of 125I-labeled insulin to rat liver and adipocyte plasma membranes has been investigated after treatment of the membranes with agents that modify disulfide bonds or sulfhydryl groups. Dithiothreitol, a disulfide-reducing agent, produced a bimodal response in adipocyte plasma membranes with dose-dependent increases in binding occurring over the range of 0-1 mM dithiothreitol; 5 mM dithiothreitol produced decreased binding. Insulin binding reached its maximal increase at 1 mM and was 3 times control values. Scatchard analysis of the 1 mM dithiothreitol effect revealed a straight line plot indicative of one class of sites with a Ka of 1.0× 108 M-1 which is intermediate between the two Kas obtained from the curvilinear Scatchard plot of control membranes. There was a 20-fold increase in the number of intermediate-affinity receptors compared to high-affinity receptors. The increased 125I-labeled insulin binding after dithiothreitol treatment was reversed by oxidized glutathione in a dose-dependent manner. Interposition of treatment with N-ethylmaleimide, an alkylating agent, prevented oxidized glutathione from reversing the dithiothreitol effect. Reduced glutathione produced the same effect as dithiothreitol. Liver plasma membranes treated with up to 1 mM dithiothreitol exhibited a maximum increase in insulin binding of 20% compared to control. Dithiothreitol at 5 mM decreased insulin binding below that of control membranes. The results indicate that the dithiothreitol effect on insulin binding to adipocyte plasma membranes is due to disruption of disulfide bonds, and that the structural organization of the insulin receptor on the plasma membranes is different for liver and for adipose tissue. The data imply that the insulin receptors on the plasma membrane of adipocytes possess at least two functionally distinct subclasses of disulfide bond but liver insulin receptors do not.

Safety and efficacy of the C-Tb skin test to diagnose Mycobacterium tuberculosis infection, compared with an interferon γ release assay and the tuberculin skin test: a phase 3, double-blind, randomised, controlled trial.

PubMed

Ruhwald, Morten; Aggerbeck, Henrik; Gallardo, Rafael Vázquez; Hoff, Søren T; Villate, José I; Borregaard, Bettine; Martinez, José A; Kromann, Ingrid; Penas, Antón; Anibarro, Luis L; de Souza-Galvão, Maria Luiza; Sánchez, Francisca; Rodrigo-Pendás, Jose Ángel; Noguera-Julian, Antoni; Martínez-Lacasa, Xavier; Tuñez, Maria Victoria; Fernández, Virginia Leiro; Millet, Joan P; Moreno, Antonio; Cobos, Nazaret; Miró, José M; Roldan, Llanos; Orcau, Angels; Andersen, Peter; Caylá, Joan A

2017-04-01

Targeted screening and treatment of Mycobacterium tuberculosis infection substantially reduces the risk of developing active tuberculosis. C-Tb (Statens Serum Institute, Copenhagen, Denmark) is a novel specific skin test based on ESAT-6 and CFP10 antigens. We investigated the safety and diagnostic potential of C-Tb compared with established tests in the contact-tracing setting. Negative controls, close contacts, occasional contacts, and patients with active pulmonary tuberculosis were enrolled at 13 centres in Spain. We compared C-Tb with the QuantiFERON-TB Gold In-Tube ([QFT] Qiagen, Hilden, Germany) interferon γ release assay (IGRA) and the purified protein derivative (PPD) RT 23 tuberculin skin test ([TST] Statens Serum Institute). All participants older than 5 years were tested with QFT. Some participants in the negative control group received C-Tb without the TST to test for potential interactions between C-Tb and PPD RT 23. The rest were randomly assigned in blocks of ten and tested with both C-Tb and TST, with five in each block receiving injection of C-Tb in the right arm and the TST in the left arm and five vice versa. The primary and safety analyses were done in all participants randomly assigned to a group who received any test. This trial is registered with ClinicalTrials.gov, number NCT01631266, and with EudraCT, number 2011-005617-36. From July 24, 2012, to Oct 2, 2014, 979 participants were enrolled, of whom 263 were negative controls, 299 were occasional contacts, 316 were close contacts, and 101 were patients with tuberculosis. 970 (99%) participants completed the trial. Induration sizes were similar for C-Tb and TST, but TST positivity was affected by BCG vaccination status. We found a strong positive trend towards C-Tb test positivity with increasing risk of infection, from 3% in negative controls to 16% in occasional contacts, to 43% in close contacts. C-Tb and QFT results were concordant in 785 (94%) of 834 participants aged 5 years and older

Superdiffusion of Carbon by Vacancies Irradiated with Soft X-Rays in CZ Silicon / Superdifūzija Ar Vakancēm Iestarota Ar Mīkstajiem Rentgenstariem CZ Silīcijā

NASA Astrophysics Data System (ADS)

Janavičius, A. J.; Mekys, A.; Purlys, R.; Norgėla, Ž.; Daugėla, S.; Rinkūnas, R.

2015-10-01

The soft X-ray photons absorbed in the inner K, L, M shells of Si atoms produce photoelectrons and Auger electrons, thus generating vacancies, interstitials and metastable oxygen complexes. The samples of Czochralski silicon crystals covered with 0.1 μm thickness layer of carbon have been irradiated by X-rays using different voltages of Cu anode of the Russian diffractometer DRON-3M. The influence of X-rays on the formation of point defects and vacancy complexes, and their dynamics in Cz-Si crystals have been studied by infrared absorption. We have measured and calculated dynamics of concentration of carbon and interstitial oxygen using FTIR spectroscopy at room temperature after irradiation by soft X-rays. Using transmittance measurements and nonlinear diffusion theory we have calculated densities increasing for substitutional carbon and interstitial oxygen by reactions and very fast diffusion. The superdiffusion coefficients of carbon in silicon at room temperature generated by X-rays are about hundred thousand times greater than diffusion coefficients obtained for thermodiffusion. Rezumējums: Rentgena staru fotoni, absorbēti Si atoma iekšējos slāņos, izstaro fotoelektronus un Ožē elektronus, ģenerējot vakances, starpmezglu silīcija atomus, vakanču un skābekļa kompleksus. Čohraļska silīcija kristāli, kas pārklāti ar oglekli 0.1 μm biezuma kārtā, tika apstaroti ar rentgena stariem, izmantojot krievu difraktometru DRON-3M. Oglekļa un skābekļa difūzija un koncentrāciju izmaiņa silīcijā tika izmērīta izmantojot infrasarkano staru FTIR spektroskopiju. Rentgena staru ģenerētās ļoti ātrās oglekļa difūzijas vai superdifūzijas koeficients istabas temperatūrā silīcijā ir simtiem tūkstošu reižu lielāks nekā termodifūzijas gadījumā.

Domain analysis of 3 Keto Acyl-CoA synthase for structural variations in Vitis vinifera and Oryza brachyantha using comparative modelling.

PubMed

Sagar, Mamta; Pandey, Neetesh; Qamar, Naseha; Singh, Brijendra; Shukla, Akanksha

2015-03-01

The long chain fatty acids incorporated into plant lipids are derived from the iterative addition of C2 units which is provided by malonyl-CoA to an acyl-CoA after interactions with 3-ketoacyl-CoA synthase (KCS), found in several plants. This study provides functional characterization of three 3 ketoacyl CoA synthase like proteins in Vitis vinifera (one) and Oryza brachyantha (two proteins). Sequence analysis reveals that protein of Oryza brachyantha shows 96% similarity to a hypothetical protein in Sorghum bicolor; total 11 homologs were predicted in Sorghum bicolor. Conserved domain prediction confirm the presence of FAE1/Type III polyketide synthase-like protein, Thiolase-like, subgroup; Thiolase-like and 3-Oxoacyl-ACP synthase III, C-terminal and chalcone synthase like domain but very long chain 3-keto acyl CoA domain is absent. All three proteins were found to have Chalcone and stilbene synthases C terminal domain which is similar to domain of thiolase and β keto acyl synthase. Its N terminal domain is absent in J3M9Z7 protein of Oryza brachyantha and F6HH63 protein of Vitis vinifera. Differences in N-terminal domain is responsible for distinguish activity. The J3MF16 protein of Oryza brachyantha contains N terminal domain and C terminal domain and characterized using annotation of these domains. Domains Gcs (streptomyces coelicolor) and Chalcone-stilbene synthases (KAS) in 2-pyrone synthase (Gerbera hybrid) and chalcone synthase 2 (Medicago sativa) were found to be present in three proteins. This similarity points toward anthocyanin biosynthetic process. Similarity to chalcone synthase 2 reveals its possible role in Naringenine and Chalcone synthase like activity. In 3 keto acyl CoA synthase of Oryza brachyantha. Active site residues C-240, H-407, N-447 are present in J3MF16 protein that are common in these three protein at different positions. Structural variations among dimer interface, product binding site, malonyl-CoA binding sites, were predicted in

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, Ryne C.; Zhou, Jing; Smith, Jeremy C.

In redox processes in complex transition metal-containing species are often intimately associated with changes in ligand protonation states and metal coordination number. Moreover, a major challenge is therefore to develop consistent computational approaches for computing pH-dependent redox and ligand dissociation properties of organometallic species. Reduction of the Co center in the vitamin B12 derivative aquacobalamin can be accompanied by ligand dissociation, protonation, or both, making these properties difficult to compute accurately. We examine this challenge here by using density functional theory and continuum solvation to compute Co ligand binding equilibrium constants (Kon/off), pKas and reduction potentials for models of aquacobalaminmore » in aqueous solution. We consider two models for cobalamin ligand coordination: the first follows the hexa, penta, tetra coordination scheme for Co III, Co II, and Co I species, respectively, and the second model features saturation of each vacant axial coordination site on Co II and Co I species with a single, explicit water molecule to maintain six directly interacting ligands or water molecules in each oxidation state. Comparing these two coordination schemes in combination with five dispersion-corrected density functionals, we find that the accuracy of the computed properties is largely independent of the scheme used, but including only a continuum representation of the solvent yields marginally better results than saturating the first solvation shell around Co throughout. PBE performs best, displaying balanced accuracy and superior performance overall, with RMS errors of 80 mV for seven reduction potentials, 2.0 log units for five pK as and 2.3 log units for two log K on/off values for the aquacobalamin system. Furthermore, we find that the BP86 functional commonly used in corrinoid studies suffers from erratic behavior and inaccurate descriptions of Co axial ligand binding, leading to substantial errors in

The Starburst-AGN connection: quenching the fire and feeding the monster

NASA Astrophysics Data System (ADS)

Melnick, Jorge; Telles, Eduardo; De Propris, Roberto; Chu, Zhang-Hu

2015-10-01

The merger of two spiral galaxies is believed to be one of the main channels for the production of elliptical and early-type galaxies. In the process, the system becomes an (ultra) luminous infrared galaxy, or (U)LIRG, that morphs to a quasar, to a K+A galaxy, and finally to an early-type galaxy. The time scales for this metamorphosis are only loosely constrained by observations. In particular, the K+A phase should follow immediately after the quasi stellar object (QSO) phase during which the dust and gas remaining from the (U)LIRG phase are expelled by the active galactic nucleus (AGN). An intermediate class of QSOs with K+A spectral signatures, the post-starburst QSOs (PSQ), may represent the transitional phase between QSOs and K+As. We have compiled a sample of 72 bona fide z < 0.5 PSQ from the SDSS DR7 QSO catalogue. We find the intermediate age populations in this sample to be on average significantly weaker and metal poorer than their putative descendants, the K+A galaxies. The typical spectral energy distribution of PSQ is well fitted by three components: starlight; an obscured power-law; and a hot dust component required to reproduce the mid-IR fluxes. From the slope and bolometric luminosity of the power-law component we estimate typical masses and accretion rates of the AGN, but we find little evidence of powerful radio-loud or strong X-ray emitters in our sample. This may indicate that the power-law component originates in a nuclear starburst rather than in an AGN, as expected if the bulk of their young stars are still being formed, or that the AGN is still heavily enshrouded in dust and gas. We find that both alternatives are problematic and that more and better optical, X-ray, and mm-wave observations are needed to elucidate the evolutionary history of PSQ.

Structural and dynamical aspects of Streptococcus gordonii FabH through molecular docking and MD simulations.

PubMed

Shamim, Amen; Abbasi, Sumra Wajid; Azam, Syed Sikander

2015-07-01

β-Ketoacyl-ACP-synthase III (FabH or KAS III) has become an attractive target for the development of new antibacterial agents which can overcome the multidrug resistance. Unraveling the fatty acid biosynthesis (FAB) metabolic pathway and understanding structural coordinates of FabH will provide valuable insights to target Streptococcus gordonii for curing oral infection. In this study, we designed inhibitors against therapeutic target FabH, in order to block the FAB pathway. As compared to other targets, FabH has more interactions with other proteins, located on the leading strand with higher codon adaptation index value and associated with lipid metabolism category of COG. Current study aims to gain in silico insights into the structural and dynamical aspect of S. gordonii FabH via molecular docking and molecular dynamics (MD) simulations. The FabH protein is catalytically active in dimerization while it can lock in monomeric state. Current study highlights two residues Pro88 and Leu315 that are close to each other by dimerization. The active site of FabH is composed of the catalytic triad formed by residues Cys112, His249, and Asn279 in which Cys112 is involved in acetyl transfer, while His249 and Asn279 play an active role in decarboxylation. Docking analysis revealed that among the studied compounds, methyl-CoA disulfide has highest GOLD score (82.75), binding affinity (-11 kcal/mol) and exhibited consistently better interactions. During MD simulations, the FabH structure remained stable with the average RMSD value of 1.7 Å and 1.6 Å for undocked protein and docked complex, respectively. Further, crucial hydrogen bonding of the conserved catalytic triad for exhibiting high affinity between the FabH protein and ligand is observed by RDF analysis. The MD simulation results clearly demonstrated that binding of the inhibitor with S. gordonii FabH enhanced the structure and stabilized the dimeric FabH protein. Therefore, the inhibitor has the potential to become

Toward Quantitatively Accurate Calculation of the Redox-Associated Acid–Base and Ligand Binding Equilibria of Aquacobalamin

DOE PAGES

Johnston, Ryne C.; Zhou, Jing; Smith, Jeremy C.; ...

2016-07-08

In redox processes in complex transition metal-containing species are often intimately associated with changes in ligand protonation states and metal coordination number. Moreover, a major challenge is therefore to develop consistent computational approaches for computing pH-dependent redox and ligand dissociation properties of organometallic species. Reduction of the Co center in the vitamin B12 derivative aquacobalamin can be accompanied by ligand dissociation, protonation, or both, making these properties difficult to compute accurately. We examine this challenge here by using density functional theory and continuum solvation to compute Co ligand binding equilibrium constants (Kon/off), pKas and reduction potentials for models of aquacobalaminmore » in aqueous solution. We consider two models for cobalamin ligand coordination: the first follows the hexa, penta, tetra coordination scheme for Co III, Co II, and Co I species, respectively, and the second model features saturation of each vacant axial coordination site on Co II and Co I species with a single, explicit water molecule to maintain six directly interacting ligands or water molecules in each oxidation state. Comparing these two coordination schemes in combination with five dispersion-corrected density functionals, we find that the accuracy of the computed properties is largely independent of the scheme used, but including only a continuum representation of the solvent yields marginally better results than saturating the first solvation shell around Co throughout. PBE performs best, displaying balanced accuracy and superior performance overall, with RMS errors of 80 mV for seven reduction potentials, 2.0 log units for five pK as and 2.3 log units for two log K on/off values for the aquacobalamin system. Furthermore, we find that the BP86 functional commonly used in corrinoid studies suffers from erratic behavior and inaccurate descriptions of Co axial ligand binding, leading to substantial errors in

L2-norm multiple kernel learning and its application to biomedical data fusion

PubMed Central

2010-01-01

computational burden of MKL, this paper proposes several novel LSSVM based MKL algorithms. Systematic comparison on real data sets shows that LSSVM MKL has comparable performance as the conventional SVM MKL algorithms. Moreover, large scale numerical experiments indicate that when cast as semi-infinite programming, LSSVM MKL can be solved more efficiently than SVM MKL. Availability The MATLAB code of algorithms implemented in this paper is downloadable from http://homes.esat.kuleuven.be/~sistawww/bioi/syu/l2lssvm.html. PMID:20529363

Clinical Practice Guideline: Hoarseness (Dysphonia) (Update) Executive Summary.

PubMed

Stachler, Robert J; Francis, David O; Schwartz, Seth R; Damask, Cecelia C; Digoy, German P; Krouse, Helene J; McCoy, Scott J; Ouellette, Daniel R; Patel, Rita R; Reavis, Charles Charlie W; Smith, Libby J; Smith, Marshall; Strode, Steven W; Woo, Peak; Nnacheta, Lorraine C

2018-03-01

prior to visualization of the larynx. (2) Clinicians should not prescribe antireflux medications to treat isolated dysphonia, based on symptoms alone attributed to suspected gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR), without visualization of the larynx. (3) Clinicians should not routinely prescribe corticosteroids in patients with dysphonia prior to visualization of the larynx. The policy level for the following recommendation about laryngoscopy at any time was an option: (1) Clinicians may perform diagnostic laryngoscopy at any time in a patient with dysphonia. Differences from Prior Guideline (1) Incorporating new evidence profiles to include the role of patient preferences, confidence in the evidence, differences of opinion, quality improvement opportunities, and any exclusion to which the action statement does not apply (2) Inclusion of 3 new guidelines, 16 new systematic reviews, and 4 new randomized controlled trials (3) Inclusion of a consumer advocate on the guideline update group (4) Changes to 9 KASs from the original guideline (5) New KAS 3 (escalation of care) and KAS 13 (outcomes) (6) Addition of an algorithm outlining KASs for patients with dysphonia.

Structural specificity of chloroquine-hematin binding related to inhibition of hematin polymerization and parasite growth.

PubMed

Vippagunta, S R; Dorn, A; Matile, H; Bhattacharjee, A K; Karle, J M; Ellis, W Y; Ridley, R G; Vennerstrom, J L

1999-11-04

Considerable data now support the hypothesis that chloroquine (CQ)-hematin binding in the parasite food vacuole leads to inhibition of hematin polymerization and parasite death by hematin poisoning. To better understand the structural specificity of CQ-hematin binding, 13 CQ analogues were chosen and their hematin binding affinity, inhibition of hematin polymerization, and inhibition of parasite growth were measured. As determined by isothermal titration calorimetry (ITC), the stoichiometry data and exothermic binding enthalpies indicated that, like CQ, these analogues bind to two or more hematin mu-oxo dimers in a cofacial pi-pi sandwich-type complex. Association constants (K(a)'s) ranged from 0.46 to 2.9 x 10(5) M(-1) compared to 4.0 x 10(5) M(-1) for CQ. Remarkably, we were not able to measure any significant interaction between hematin mu-oxo dimer and 11, the 6-chloro analogue of CQ. This result indicates that the 7-chloro substituent in CQ is a critical structural determinant in its binding affinity to hematin mu-oxo dimer. Molecular modeling experiments reinforce the view that the enthalpically favorable pi-pi interaction observed in the CQ-hematin mu-oxo dimer complex derives from a favorable alignment of the out-of-plane pi-electron density in CQ and hematin mu-oxo dimer at the points of intermolecular contact. For 4-aminoquinolines related to CQ, our data suggest that electron-withdrawing functional groups at the 7-position of the quinoline ring are required for activity against both hematin polymerization and parasite growth and that chlorine substitution at position 7 is optimal. Our results also confirm that the CQ diaminoalkyl side chain, especially the aliphatic tertiary nitrogen atom, is an important structural determinant in CQ drug resistance. For CQ analogues 1-13, the lack of correlation between K(a) and hematin polymerization IC(50) values suggests that other properties of the CQ-hematin mu-oxo dimer complex, rather than its association

Aspartate-Histidine Interaction in the Retinal Schiff Base Counterion of the Light-Driven Proton Pump of Exiguobacterium sibiricum†

PubMed Central

Balashov, S.P.; Petrovskaya, L.E.; Lukashev, E.P.; Imasheva, E.S.; Dioumaev, A.K.; Wang, J.M.; Sychev, S.V.; Dolgikh, D.A.; Rubin, A.B.; Kirpichnikov, M.P.; Lanyi, J.K.

2012-01-01

One of the distinctive features of eubacterial retinal based proton pumps, proteorhodopsins, xanthorhodopsin and others, is hydrogen bonding of the key aspartate residue, the counterion to the retinal Schiff base, to a histidine. We describe properties of the recently found eubacterium proton pump from Exiguobacterium sibiricum (named ESR) expressed in E. coli, especially features that depend on Asp-His interaction, the protonation state of the key aspartate, Asp85, and its ability to accept proton from the Schiff base during the photocycle. Proton pumping by liposomes and E. coli cells containing ESR occurs in a broad pH range above pH 4.5. Large light-induced pH changes indicate that ESR is a potent proton pump. Replacement of His57 with methionine or asparagine strongly affects the pH dependent properties of ESR. In the H57M mutant a dramatic decrease in the quantum yield of chromophore fluorescence emission and a 45 nm blue shift of the absorption maximum upon raising the pH from 5 to 8 indicates deprotonation of the counterion with a pKa of 6.3, which is also the pKa at which the M intermediate is observed in the photocycle of the protein solubilized in detergent (DDM). This is in contrast with the wild type protein, in which the same experiments show that the major fraction of Asp85 is deprotonated at pH > 3 and that it protonates only at low pH, with a pKa of 2.3. The M intermediate in the wild type photocycle accumulates only at high pH, with an apparent pKa of 9 from deprotonation of a residue interacting with Asp85, presumably His57. In liposomes reconstituted with ESR the pKas for M formation and spectral shifts are 2–3 pH units lower than in DDM. The distinctively different pH dependencies of the protonation of Asp85 and the accumulation of the M intermediate in the wild type protein vs. the H57M mutant indicate that there is strong Asp-His interaction, which substantially lowers the pKa of Asp85 by stabilizing its deprotonated state. PMID:22738070

Advanced Concept for Creation of Security Holograms / PROGRESĪVĀ Koncepcija AIZSARDZĪBAS Hologrammas Izveidei

NASA Astrophysics Data System (ADS)

Bulanovs, A.; Gerbreders, S.

2013-12-01

A new concept is proposed for digital hologram production along with the relevant techniques developed in our laboratory. The main idea of the concept is to maximally separate the calculation of hologram from its optical recording on the light-sensitive media. A special file format containing information on each holographic pixel is created at the stage of calculation. The file is a device-independent by structure, and can be employed for recording a hologram using any of the existing techniques (dot-matrix, optical matrix lithography, e-beam lithography). An optical lithography device is applied to calculate the images for a spatial light modulator at the stage of hologram recording in accordance with the data from the file and in conformity with the hardware features of the device. The proposed method was tested and successfully used to record security holograms. For commercial use a software package and an optical recording system have been developed. Šajā rakstā tiek apskatītas koncepcijas un metodes, kuras tiek izmantotas drošības hologrammu ražošanai mūsu laboratorijā. Koncepcijas galvenā ideja ir hologrammas aprēķina posmu maksimālais sadalījums no hologrammu optiskā ieraksta uz gaismas jūtīgām vidēm. Hologrammas aprēķina posmā tiek izveidots īpaša formāta fails, kas satur pilnu informāciju par katru hologrāfisko pikseli. Pēc struktūras fails ir neatkarīgs no ierīces un to var izmantot hologrammas ierakstam pēc jebkuras no esošajām tehnoloģijām. Hologrammas ieraksta posmā optiskā litogrāfijas iekārta pēc faila datiem veic SLM (Spatial Light Modulator) attēla aprēķinu, ievērojot iekārtas darbības īpatnības. Piedāvātā metode ir pārbaudīta un veiksmīgi tiek izmantota drošības hologrammu ierakstam. Izstrādāta programmu pakete un optiskā ieraksta iekārta komerciālai izmantošanai.

Virologic and immunologic outcome of HAART in Human Immunodeficiency Virus (HIV)-1 infected patients with and without tuberculosis (TB) and latent TB infection (LTBI) in Addis Ababa, Ethiopia.

PubMed

Kassa, Desta; Gebremichael, Gebremedhin; Alemayehu, Yodit; Wolday, Dawit; Messele, Tsehaynesh; van Baarle, Debbie

2013-01-01

HIV/TB coinfection remains a major challenge even after the initiation of HAART. Little is known about Mycobacterium tuberculosis (Mtb) specific immune restoration in relation to immunologic and virologic outcomes after long-term HAART during co-infections with latent and active TB. A total of 232 adults, including 59 HIV patients with clinical TB (HIV + TB+), 125 HIV patients without clinical TB (HIV + TB-), 13 HIV negative active TB patients (HIV-TB+), and 10 HIV negative Tuberculin Skin TST positive (HIV-TST+), and 25 HIV-TST- individuals were recruited. HAART was initiated in 113 HIV + patients (28 TB + and 85 TB-), and anti-TB treatment for all TB cases. CD4+ T-cell count, HIV RNA load, and IFN-γ responses to ESAT-6/CFP-10 were measured at baseline, 6 months (M6), 18 months (M18) and 24 months (M24) after HAART initiation. The majority of HIV + TB- (70%, 81%, 84%) as well as HIV + TB + patients (60%, 77%, 80%) had virologic success (HIV RNA < 50 copies/ml) by M6, M18 and M24, respectively. HAART also significantly increased CD4+ T-cell counts at 2 years in HIV + TB + (from 110.3 to 289.9 cells/μl), HIV + TB- patients (197.8 to 332.3 cells/μl), HIV + TST- (199 to 347 cells/μl) and HIV + TST + individuals (195 to 319 cells/μl). Overall, there was no significant difference in the percentage of patients that achieved virologic success and in total CD4+ counts increased between HIV patients with and without TB or LTBI. The Mtb specific IFN-γ response at baseline was significantly lower in HIV + TB + (3.6 pg/ml) compared to HIV-TB + patients (34.4 pg/ml) and HIV + TST + (46.3 pg/ml) individuals; and in HIV-TB + patients compared to HIV-TST + individuals (491.2 pg/ml). By M18 on HAART, the IFN-γ response remained impaired in HIV + TB + patients (18.1 pg/ml) while it normalized in HIV + TST + individuals (from 46.3 to 414.2 pg/ml). Our data show that

Clinical Practice Guideline: Hoarseness (Dysphonia) (Update).

PubMed

Stachler, Robert J; Francis, David O; Schwartz, Seth R; Damask, Cecelia C; Digoy, German P; Krouse, Helene J; McCoy, Scott J; Ouellette, Daniel R; Patel, Rita R; Reavis, Charles Charlie W; Smith, Libby J; Smith, Marshall; Strode, Steven W; Woo, Peak; Nnacheta, Lorraine C

2018-03-01

prior to visualization of the larynx. (2) Clinicians should not prescribe antireflux medications to treat isolated dysphonia, based on symptoms alone attributed to suspected gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR), without visualization of the larynx. (3) Clinicians should not routinely prescribe corticosteroids for patients with dysphonia prior to visualization of the larynx. The policy level for the following recommendation about laryngoscopy at any time was an option: (1) Clinicians may perform diagnostic laryngoscopy at any time in a patient with dysphonia. Disclaimer This clinical practice guideline is not intended as an exhaustive source of guidance for managing dysphonia (hoarseness). Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgment or establish a protocol for all individuals with this condition, and it may not provide the only appropriate approach to diagnosing and managing this problem. Differences from Prior Guideline (1) Incorporation of new evidence profiles to include the role of patient preferences, confidence in the evidence, differences of opinion, quality improvement opportunities, and any exclusion to which the action statement does not apply (2) Inclusion of 3 new guidelines, 16 new systematic reviews, and 4 new randomized controlled trials (3) Inclusion of a consumer advocate on the guideline update group (4) Changes to 9 KASs from the original guideline (5) New KAS 3 (escalation of care) and KAS 13 (outcomes) (6) Addition of an algorithm outlining KASs for patients with dysphonia.

Proton Transfer from C-6 of Uridine 5′-Monophosphate Catalyzed by Orotidine 5′-Monophosphate Decarboxylase: Formation and Stability of a Vinyl Carbanion Intermediate and the Effect of a 5-Fluoro Substituent

PubMed Central

Tsang, Wing-Yin; Wood, B. McKay; Wong, Freeman M.; Wu, Weiming; Gerlt, John A.; Amyes, Tina L.; Richard, John P.

2012-01-01

The exchange for deuterium of the C-6 protons of uridine 5′-monophosphate (UMP) and 5-fluorouridine 5′-monophosphate (F-UMP) catalyzed by yeast orotidine 5′-monophosphate decarboxylase (ScOMPDC) at pD 6.5 – 9.3 and 25 °C was monitored by 1H NMR spectroscopy. Deuterium exchange proceeds by proton transfer from C-6 of the bound nucleotide to the deprotonated side chain of Lys-93 to give the enzyme-bound vinyl carbanion. The pD-rate profiles for kcat give turnover numbers for deuterium exchange into enzyme-bound UMP and F-UMP of 1.2 × 10−5 and 0.041 s−1, respectively, so that the 5-fluoro substituent results in a 3400-fold increase in the first-order rate constant for deuterium exchange. The binding of UMP and F-UMP to ScOMPDC results in 0.5 and 1.4 unit decreases, respectively, in the pKa of the side chain of the catalytic base Lys-93, showing that these nucleotides bind preferentially to the deprotonated enzyme. We also report the first carbon acid pKas for proton transfer from C-6 of uridine (pKCH = 28.8) and 5-fluorouridine (pKCH = 25.1) in aqueous solution. The stabilizing effects of the 5-fluoro substituent on C-6 carbanion formation in solution (5 kcal/mol) and at ScOMPDC (6 kcal/mol) are similar. The binding of UMP and F-UMP to ScOMPDC results in a greater than 5 × 109-fold increase in the equilibrium constant for proton transfer from C-6 so that ScOMPDC stabilizes the bound vinyl carbanions, relative to the bound nucleotides, by at least 13 kcal/mol. The pD-rate profile for kcat/Km for deuterium exchange into F-UMP gives the intrinsic second-order rate constant for exchange catalyzed by the deprotonated enzyme as 2300 M−1 s−1. This was used to calculate a total rate acceleration for ScOMPDC-catalyzed deuterium exchange of 3 × 1010 M−1, which corresponds to a transition state stabilization for deuterium exchange of 14 kcal/mol. We conclude that a large portion of the total transition state stabilization for the decarboxylation of

Arsenite oxidation by H 2O 2 in aqueous solutions

NASA Astrophysics Data System (ADS)

Pettine, Maurizio; Campanella, Luigi; Millero, Frank J.

1999-09-01

The rates of the oxidation of As( III) with H 2O 2 were measured in NaCl solutions as a function of pH (7.5-10.3), temperature (10-50C) and ionic strength ( I = 0.01-4). The rate of the oxidation of As( III) with H 2O 2 can be described by the general expression: d[As( III)]/ dt = k[As( III)] [H 2O 2] where k (mol/L -1 min -1) can be determined from (σ = ±0.12) log k=5.29+1.41 pH-0.57 I+1.40 I0.5-4898/ T. The effect of pH on the rates indicates that the reaction is due to AsO( OH) 2-+ H2O2k 1→productsAsO2( OH) 2-+ H2O2k 2→products, AsO33-+ H2O2k 3→products where k = k1 α AsO(OH) 2- + k2 α AsO 2(OH) 2- + k3 α AsO 3 3- and α i are the molar fraction of species i. The values of k1 = 42 ± 20, k2 = (8 ± 1) × 10 4, and k3 = (72 ± 18) × 10 6 mol/L -1 min -1 were found at 25C and I = 0.01 mol/L. The undissociated As(OH) 3 does not react with H 2O 2. The effect of ionic strength on the rate constants has been attributed to the effect of ionic strength on the speciation of As( III). The rate expression has been shown to be valid for NaClO 4 solutions, northern Adriatic sea waters, and Tiber River waters. The cations Fe 2+ and Cu 2+ were found to exert a catalytic effect on the rates. Cu 2+ plays a role at concentration levels (>0.1 μmol/L) which are typical of polluted aquatic systems, while Fe 2+ is important at levels which may be found in lacustrine environments (>5-10 μmol/L). The reaction of As( III) with H 2O 2 may play a role in marine and lacustrine surface waters limiting the accumulation of As( III) resulting from biologically mediated reduction processes of As( V).

How active site protonation state influences the reactivity and ligation of the heme in chlorite dismutase

PubMed Central

Streit, Bennett R.; Blanc, Béatrice; Lukat-Rodgers, Gudrun S.; Rodgers, Kenton R.; DuBois, Jennifer L.

2010-01-01

Chlorite dismutase catalyzes O2 release from chlorite with exquisite efficiency and specificity. The spectroscopic properties, ligand binding affinities, and steady state kinetics of chlorite dismutase from Dechloromonas aromatica were examined over pH 3–11.5 to gain insight into how the protonation state of the heme environment influences dioxygen formation. An acid/base transition was observed by UV/visible and resonance Raman spectroscopy with a pKa of 8.7, 2–3 pH units below analogous transitions observed in typical His-ligated peroxidases. This transition marks the conversion of a five coordinate high spin Fe(III) to a mixed high/low spin ferric-hydroxide, as confirmed by resonance Raman (rR) spectroscopy. The two Fe–OH stretching frequencies are quite low, consistent with a weak Fe–OH bond, despite the nearly neutral imidazole side chain of the proximal histidine ligand. The hydroxide is proposed to interact strongly with a distal H-bond donor, thereby weakening the Fe–OH bond. The rR spectra of Cld-CO as a function of pH reveal two forms of the complex, one in which there is minimal interaction of distal residues with the carbonyl oxygen and another, acidic form in which the oxygen is under the influence of positive charge. Recent crystallographic data reveal arginine 183 as the lone H-bond donating residue in the distal pocket. It is likely that this Arg is the strong, positively charged H-bond donor implicated by vibrational data to interact with exogenous axial heme ligands. The same Arg in its neutral (pKa ~ 6.5) form also appears to act as the active site base in binding reactions of protonated ligands, such as HCN, to ferric Cld. The steady state profile for the rate of chlorite decomposition is characterized by these same pKas. The 5 coordinate high spin acidic Cld is more active than the alkaline hydroxide-bound form. The acid form decomposes chlorite most efficiently when the distal Arg is protonated/cationic (maximum kcat = 2.0 (±0.6) �

Progresses in Ab Initio QM/MM Free Energy Simulations of Electrostatic Energies in Proteins: Accelerated QM/MM Studies of pKa, Redox Reactions and Solvation Free Energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamerlin, Shina C. L.; Haranczyk, Maciej; Warshel, Arieh

2009-03-01

Hybrid quantum mechanical / molecular mechanical (QM/MM) approaches have been used to provide a general scheme for chemical reactions in proteins. However, such approaches still present a major challenge to computational chemists, not only because of the need for very large computer time in order to evaluate the QM energy but also because of the need for propercomputational sampling. This review focuses on the sampling issue in QM/MM evaluations of electrostatic energies in proteins. We chose this example since electrostatic energies play a major role in controlling the function of proteins and are key to the structure-function correlation of biologicalmore » molecules. Thus, the correct treatment of electrostatics is essential for the accurate simulation of biological systems. Although we will be presenting here different types of QM/MM calculations of electrostatic energies (and related properties), our focus will be on pKa calculations. This reflects the fact that pKa of ionizable groups in proteins provide one of the most direct benchmarks for the accuracy of electrostatic models of macromolecules. While pKa calculations by semimacroscopic models have given reasonable results in many cases, existing attempts to perform pKa calculations using QM/MM-FEP have led to large discrepancies between calculated and experimental values. In this work, we accelerate our QM/MM calculations using an updated mean charge distribution and a classical reference potential. We examine both a surface residue (Asp3) of the bovine pancreatic trypsin inhibitor, as well as a residue buried in a hydrophobic pocket (Lys102) of the T4-lysozyme mutant. We demonstrate that by using this approach, we are able to reproduce the relevant sidechain pKas with an accuracy of 3 kcal/mol. This is well within the 7 kcal/mol energy difference observed in studies of enzymatic catalysis, and is thus sufficient accuracy to determine the main contributions to the catalytic energies of enzymes. We also

Charging of the Electric Vehicles in Private Sector: Technical and Economic Aspects

NASA Astrophysics Data System (ADS)

Grackova, L.; Oleinikova, I.; Klavs, G.

2014-12-01

The economic aspect considered in the work is related to the charging of an electric vehicle (EV) at a single private house when this is done every day. To perform the relevant cost estimation it was necessary to determine: the average annual electricity consumption under the condition of everyday charging an EV and the average electricity consumption off the mains for covering a distance of 100 km by an EV and the time in hours for its charging. Comparison is made for the day-time intervals from which it is possible to choose the preferable for proper loading the electric line and the most beneficial for the consumer. Under analysis are two EV connection scenarios for 100 individual households from which 10%, 20% and 30% have EVs, with 8-h duration of each charging at the current of 13A. The authors consider the consumption and electric energy payment packages which - with planned opening of the electric energy market on January 1, 2015 - will offer the clients the enterprises rendering services on the electric energy sale. Šajā rakstā tiek analizēts vidējais diennakts elektroenerģijas patēriņš un diennakts slodzes grafiki privātmājās apstākļos, kad privātmājas īpašnieki lādē elektroautomobili katru dienu vidējam brauciena attālumam 100 km. Elektroautomobiļa uzlādes režīmi tiek analizēti, ņemot vērā patēriņa elektriskās slodzes grafika kvalitāti raksturojošos rādītājus un patērētāja ekonomiskos ieguvumus. Lai novērtētu ekonomiski stimulētu patērētāju elektroautomobiļa uzlādes laika izvēles ietekmi uz diennakts elektriskās slodzes aizpildījuma koeficientu, tika izveidoti un analizēti 2 scenāriji, kas apraksta 100 privātmāju ar dažādu elektroautomobiļu piederības īpatsvaru divas atšķirīgas automobiļu uzlādes gadījumus.

Identity of Innovative Multifunctional Material Manufacturing Business in Latvia / Inovatīvu Daudzfunkcionālo Materiālu Ražotāju Identitāte Latvijā

NASA Astrophysics Data System (ADS)

Geipele, I.; Staube, T.; Ciemleja, G.; Zeltins, N.; Ekmanis, Yu.

2015-08-01

The publication comprises the results from the practical scientific investigation to define the profile and distinctions of the Latvian innovative multifunctional material manufacturing industry. The research is carried out by a holistic approach, including expert interviews, qualitative analysis of the official register data, practical survey, and financial data analysis. The paper seeks to give the detailed data on a technological profile of the mentioned representative companies, if there is a synergy or tough competition in the Latvian market. The current research is topical, because it is unique and does not have analogues in Latvia, and the research is timely due to correspondence with recently stated Research and Innovation Strategies for Smart Specialisation in Latvia. The main findings are associated with recognition of the factors that make impact on commercialisation of the finished goods, obtained financial results and planned directions of development of the respondent companies. Publikācija sniedz veiktā zinātniski praktiskā pētījuma rezultātus, kura ietvaros tika noteikts Latvijas inovatīvu daudzfunkcionālo materiālu ražotāju darbības profils un identitāte. Pētījumā tika izmantota kompleksās analīzes metode, kas ietvēra ekspertu intervijas, uzņēmumu oficiāli reģistrēto datu kvalitatīvo analīzi, zinātniski praktisko aptauju, kā arī pētāmo uzņēmumu finanšu darbības rezultātu analīzi. Zinātniskais darbs sniedz izsmeļošu informāciju par mērķa uzņēmumu tehnoloģisko profilu un pēta, vai Latvijas mērķa ražošanas nozarē ir sinerģijas vai sīvās konkurences pazīmes. Šim zinātniskajam pētījumam ir noteikta aktualitāte saskaņā ar tā unikalitāti Latvijas valsts mērogā un atbilstība Viedās specializācijas stratēģijai. Pētījuma galvenie secinājumi ir saistīti ar uzņēmumu produkcijas komercializācijas ietekmējošo faktoru apzināšanu, sasniegtajiem finansiālajiem rezultātiem un pl

Acidity of a Cu-bound histidine in the binuclear center of cytochrome C oxidase.

PubMed

Fadda, Elisa; Chakrabarti, Nilmadhab; Pomès, Régis

2005-12-01

Cytochrome c oxidase (CcO) is a crucial enzyme in the respiratory chain. Its function is to couple the reduction of molecular oxygen, which takes place in the Fea3-CuB binuclear center, to proton translocation across the mitochondrial membrane. Although several high-resolution structures of the enzyme are known, the molecular basis of proton pumping activation and its mechanism remain to be elucidated. We examine a recently proposed scheme (J. Am. Chem. Soc. 2004, 126, 1858; FEBS Lett. 2004, 566, 126) that involves the deprotonation of the CuB-bound imidazole ring of a histidine (H291 in mammalian CcO) as a key element in the proton pumping mechanism. The central feature of that proposed mechanism is that the pKa values of the imidazole vary significantly depending on the redox state of the metals in the binuclear center. We use density functional theory in combination with continuum electrostatics to calculate the pKa values, successively in bulk water and within the protein, of the Cu-bound imidazole in various Cu- and Cu-Fe complexes. From pKas in bulk water, we derived a value of -266.34 kcal.mol(-1) for the proton solvation free energy (Delta). This estimate is in close agreement with the experimental value of -264.61 kcal.mol(-1) (J. Am. Chem. Soc. 2001, 123, 7314), which reinforces the conclusion that Delta is more negative than previous values used for pKa calculations. Our approach, on the basis of the study of increasingly more detailed models of the CcO binuclear center at different stages of the catalysis, allows us to examine successively the effect of each of the two metals' redox states and of solvation on the acidity of imidazole, whose pKa is approximately 14 in bulk water. This analysis leads to the following conclusions: first, the effect of Cu ligation on the imidazole acidity is negligible regardless of the redox state of the metal. Second, results obtained for Cu-Fe complexes in bulk water indicate that Cu-bound imidazole pKa values lie within

A histidine residue of the influenza virus hemagglutinin controls the pH dependence of the conformational change mediating membrane fusion.

PubMed

Mair, Caroline M; Meyer, Tim; Schneider, Katjana; Huang, Qiang; Veit, Michael; Herrmann, Andreas

2014-11-01

The conformational change of the influenza virus hemagglutinin (HA) protein mediating the fusion between the virus envelope and the endosomal membrane was hypothesized to be induced by protonation of specific histidine residues since their pKas match the pHs of late endosomes (pK(a) of ∼ 6.0). However, such critical key histidine residues remain to be identified. We investigated the highly conserved His184 at the HA1-HA1 interface and His110 at the HA1-HA2 interface of highly pathogenic H5N1 HA as potential pH sensors. By replacing both histidines with different amino acids and analyzing the effect of these mutations on conformational change and fusion, we found that His184, but not His110, plays an essential role in the pH dependence of the conformational change of HA. Computational modeling of the protonated His184 revealed that His184 is central in a conserved interaction network possibly regulating the pH dependence of conformational change via its pKa. As the propensity of histidine to get protonated largely depends on its local environment, mutation of residues in the vicinity of histidine may affect its pK(a). The HA of highly pathogenic H5N1 viruses carries a Glu-to-Arg mutation at position 216 close to His184. By mutation of residue 216 in the highly pathogenic as well as the low pathogenic H5 HA, we observed a significant influence on the pH dependence of conformational change and fusion. These results are in support of a pK(a)-modulating effect of neighboring residues. The main pathogenic determinant of influenza viruses, the hemagglutinin (HA) protein, triggers a key step of the infection process: the fusion of the virus envelope with the endosomal membrane releasing the viral genome. Whereas essential aspects of the fusion-inducing mechanism of HA at low pH are well understood, the molecular trigger of the pH-dependent conformational change inducing fusion has been unclear. We provide evidence that His184 regulates the pH dependence of the HA

Developed Design for Humeral Head Replacement Using 3D Surface Mapping

NASA Astrophysics Data System (ADS)

Salah, H. R.

2014-12-01

Assessment of dimensional and geometrical data on the humeral head replacement (HHR) objects is essential for solving the relevant designing problems in the physics of reverse engineering (RE). In this work, 2D-assessment for human humerus was performed using the computed tomography (CT) technique within the RE plan, after which the 2D images of humeral objects were converted into 3D images. The conversion was successful and indicated a clear difference in the 2D and 3D estimates of sizes and geometry of the humerus. The authors have analyzed and confirmed experimentally the statistical information on the relevant anatomical objects. The results of finite-element simulation of the compressive stresses affecting the geometry of 3D surface mapping were analyzed using SolidWorks software. For developing the biomechanical design of an HHR object suitable biomaterials were selected, and different metal-based biomaterials are discussed as applied at various loads. New methodology is presented for the size estimation of humeral head - both anatomical and artificial - in 3D-shape. A detailed interpretation is given for the results of CT D-measurements. Izmēru un ģeometrisko datu novērtējums, kas attiecas uz pleca kaula galviņas nomaiņas (PKGN) objektiem, nepieciešams, lai risinātu virkni reversīvās inženierijas (RI) problēmu. Šajā darbā cilvēka pleca kaula galviņas divdimensiju novērtējums tika veikts ar datortomogrāfijas palīdzību (RI) ietvaros, un pēc tam objekta divdimensiju attēlojums tika pārveidots trīsdimensiju. Pārveidojums bija sekmīgs, parādot pleca kaula galviņas izmēru un ģeometrijas atšķirības starp 2D un 3D novērtējumiem. Autori izanalizēja un eksperimentāli apstiprināja statistisko informāciju pēc dotā veida anatomiskiem objektiem. Saspiešanas sasprindzinājumi, kuri ietekmē trīsdimensiju virsmas attēlojuma ģeometriju, tika analizēti ar gala-elementu simulācijas metodi, lietojot programmu Solid

In pursuit of empowerment: Sensei Nellie Kleinsmidt, race and gender challenges in South Africa.

PubMed

Jones, D E

2001-01-01

This chapter traces the way in which Nellie Kleinsmidt, known as the grandmother of karate in Africa, has negotiated discriminatory practices and overcome race and gender-related struggles, including the struggle to free the female body, in pursuit of empowerment. It explores her expectations and the constraints and frustrations she experienced, as well as the many contributions she has made to women's karate in South Africa. Nellie Kleinsmidt's karate career, which began in 1965, coincided with the early developments of South African karate. As a woman of colour her life and karate career were significantly shaped by apartheid legislation. It divided the country into areas of occupancy and residency according to race and was designed to prevent contact between the people of the government defined race groups. Black karate-kas were prohibited by law from practising karate in white designated areas. Lack of facilities and qualified instructors in areas allocated to Kleinsmidt's race group meant that she received very little formal karate instruction between 1966 and 1973. Soon after, she met Johan Roux, a white male. He was to become her chief karate instructor and life-long companion. They defied the apartheid legislation and in 1978 set up home together. They organized defiance campaigns, resisting the pressures from government to close their dojo because of its non-racial policies. Freeing her body at the broader political level involved the abolition of the race categories and all other apartheid legislation which impacted on her life choices and experiences. Initially this struggle and that of freeing her body occurred simultaneously. In her ongoing struggle against gender discrimination in the sport, it was in karate that Nellie Kleinsmidt could strive for the personal empowerment she sought. She could however not translate this into freedom in South African society itself. The impact of apartheid legislation together with the imposition of a sports moratorium

Micro-grid for on-site wind-and-hydrogen powered generation

NASA Astrophysics Data System (ADS)

Suskis, P.; Andreiciks, A.; Steiks, I.; Krievs, O.; Kleperis, J.

2014-02-01

The authors propose a micro-grid for autonomous wind-and-hydrogen power generation thus replacing such traditional fossil-fuelled equipment as domestic diesel generators, gas micro-turbines, etc. In the proposed microgrid the excess of electrical energy from a wind turbine is spent on electrolytic production of hydrogen which is then stored under low-pressure in absorbing composite material. The electrolyser has a non-traditional feeding unit and electrode coatings. The proposed DC/DC conversion topologies for different micro-grid nodes are shown to be well-designed. The prototypes elaborated for the converters and hydrogen storage media were tested and have demonstrated a good performance. Rakstā piedāvātā mikrotīkla izpēte ir veikta ar mērķi izstrādāt autonomu, uz vēja un ūdeņraža enerģiju balstītu elektroapgādes sistēmu, kas varētu aizvietot tradicionālās fosilā kurināmā sistēmas, piemēram, mājsaimniecību dīzeļa ģeneratorus, gāzes mikroturbīnas u.c. Mikrotīkla elektroapgādes sistēmā vēja agregāta saražotā elektroenerģija tiek pārveidota atbilstoši standarta maiņsprieguma elektroapgādes parametriem un piegādāta slodzei. Pārpalikusī enerģija tiek pārveidota un uzkrāta ūdeņraža formā, izmantojot elektrolīzes iekārtu un kompozītmateriālu uzkrājēju. Ja pieejamā vēja enerģija nenosedz slodzes enerģijas patēriņu, elektroenerģijas padeves funkciju ar atbilstoša energoelektronikas pārveidotāja palīdzību pārņem ūdeņraža degvielas elements. Ja, savukārt, slodzei nav nepieciešama enerģija, no vēja saražoto enerģiju izmanto elektrolīzes iekārta un tā tiek uzkrāta ūdeņraža formā, atbilstoši uzkrājēja ietilpībai. Piedāvātajā mikrotīklā ir izmantota elektrolīzes iekārta ar netradicionāliem elektrodu pārklājumiem un barošanas bloku, kā arī zemspiediena kompozītmateriālu ūdeņraža uzkrājējs. Galvenie mikrotīkla elektriskās enerģijas pārveidošanas mezgli ir

An ecodesign method for reducing the effects of hazardous substances in the product lifecycle

NASA Astrophysics Data System (ADS)

Simanovska, J.; Valters, K.; Bažbauers, G.; Luttropp, C.

2012-10-01

ārtējo vidi novēršanu. Tāpēc radīta jauna, daļēji kvantitatīva ekodizaina metode, apvienojot produktu izstrādes prasības ar zinātniskā ķīmiskā riska novērtēšanas principiem, kas piedāvā bīstamo īpašību prioritizēšanu, izmantojot Globāli harmonizētās sistēmas ķīmisko vielu klasifikācijas kodus, kā arī iedarbības un materiālu efektivitātes aspektu prioritizēšanu. Metode tika aprobēta, demonstrējot tās izmantošanu. Metode ļauj produkta izstrādātājam identificēt pārmaiņu nepieciešamību, izstrādāt ekodizaina priekšlikumus, izvērtēt alternatīvas, un palīdz uzlabot saziņu par materiālu īpašībām un ietekmi uz vidi un cilvēka veselību izejvielu un produktu piegādes ķēdē.

Wear Calculation for Sliding Friction Pairs

NASA Astrophysics Data System (ADS)

Springis, G.; Rudzitis, J.; Avisane, A.; Leitans, A.

2014-04-01

One of the principal objectives of modern production process is the improvement of quality level; this means also guaranteeing the required service life of different products and increase in their wear resistance. To perform this task, prediction of service life of fitted components is of crucial value, since with the development of production technologies and measuring devices it is possible to determine with ever increasing precision the data to be used also in analytical calculations. Having studied the prediction theories of wear process that have been developed in the course of time and can be classified into definite groups one can state that each of them has shortcomings that might strongly impair the results thus making unnecessary theoretical calculations. The proposed model for wear calculation is based on the application of theories from several branches of science to the description of 3D surface micro-topography, assessing the material's physical and mechanical characteristics, substantiating the regularities in creation of the material particles separated during the wear process and taking into consideration definite service conditions of fittings. ums Mūsdienu ražošanas procesa viens no pamatmērķiem ir produkcijas kvalitātes līmeņa paaugstināšana, tas nozīmē arī dažādu izstrādājumu nepieciešamā kalpošanas laika nodrošināšanu un nodilumizturības palielināšanu. Svarīga loma šī uzdevuma sasniegšanā ir salāgojamo detaļu kalpošanas laika prognozēšanai, kas ir ļoti aktuāls jautājums, jo attīstoties dažādām ražošanas, kā arī mēriekārtu tehnoloģijām, kļūst iespējams arvien precīzāk noteikt nepieciešamos datus, kuri vēlāk tiek izmantoti arī analītiskajos aprēķinos. Apskatot laika gaitā izstrādātās dilšanas procesa prognozēšanas teorijas, kuras var klasificēt, apkopojot tās noteiktās grupās, ņemot par pamatu līdzīgas teorētiskās pieejas, jāsaka, ka katrai no tām piemīt da

Research into the 3d roughness of a rough surface

NASA Astrophysics Data System (ADS)

Avisane, A.; Rudzitis, J.; Springis, G.

2014-02-01

One of the most important parameters in determination of the deformation associated with roughness is its height on the surface. The authors study the density of probability distribution as related to the surface peak height (SPH) and estimate the mathematical expectation (ME) of SPH for the roughness values above a determined deformation level. In the contact theory, the surface is modelled as a normal random field described by the Nayak SPH formula. Since this formula is practically inapplicable in the engineering tasks, the authors propose to replace it by a simpler distribution law. For this purpose the former is compared with two other formulas obeying the most known probability distribution laws: of normal distribution (Gauss') law and Rayleigh's law. Comparison of these three formulas made it possible to derive a simpler yet sufficiently precise one. In the work, the numerical values of the density of SPH probability distribution and the relevant ME values at different deformation levels for all three formulas. ums Lai noteiktu negludumu deformāciju, viens no būtiskākajiem parametriem ir virsmas negludumu augstums. Šajā rakstā apskatītas un salīdzinātas trīs dažādas formulas virsmas izciļņu augstuma varbūtību sadalījuma blīvuma aprēķināšanai un virsmas izciļņu augstuma matemātiskās sagaidāmās vērtības noteikšanai tiem nelīdzenumiem, kas atrodas virs nosacīta deformācijas līmeņa γ. Kontaktteorijā virsma tiek modelēta kā normāls gadījuma lauks. Šādam normālajam gadījuma laukam izciļņu augstuma varbūtību sadalījuma blīvuma likumu ir ieguvis P.R. Naijaks, taču šī izteiksme ir praktiski nepiemērojama inženieruzdevumu risināšanai, tāpēc šajā darbā ir noskaidrots, ka esošo formulu ir iespējams aizstāt ar vienkāršāku sadalījuma likumu. Ir apskatīta P.R. Naijaka formula un divi pazīstamākie varbūtību sadalījuma likumi: normālais sadalījuma (Gausa) likums un Releja likums. Salīdzinot �

Kinetics of the hydrolysis of N-benzoyl-l-serine methyl ester catalysed by bromelain and by papain. Analysis of modifier mechanisms by lattice nomography, computational methods of parameter evaluation for substrate-activated catalyses and consequences of postulated non-productive binding in bromelain- and papain-catalysed hydrolyses

PubMed Central

Wharton, Christopher W.; Cornish-Bowden, Athel; Brocklehurst, Keith; Crook, Eric M.

1974-01-01

of α-N-benzoyl-l-arginine amide; Km1 and k for the serine ester hydrolysis are somewhat similar to Km and kcat. for the arginine amide hydrolysis and Kas and k′ for the serine ester hydrolysis are somewhat similar to Km and kcat. for the arginine ester hydrolysis. 9. A previous interpretation of the inter-relationships of the values of kcat. and Km for the bromelain-catalysed hydrolysis of the arginine ester and amide substrates is discussed critically and an alternative interpretation involving substantial non-productive binding of the arginine amide substrate to bromelain is suggested. 10. The parameters for the bromelain-catalysed hydrolysis of the serine ester substrate are tentatively interpreted in terms of non-productive binding in the binary complex and a decrease of this type of binding by ternary complex-formation. 11. The Michaelis parameters for the papain-catalysed hydrolysis of the serine ester substrate (Km=52±4mm, kcat.=2.80±0.1s−1 at pH7.0, I=0.1, 25.0°C) are similar to those for the papain-catalysed hydrolysis of methyl hippurate. 12. Urea and guanidine hydrochloride at concentrations of 1m have only small effects on the kinetic parameters for the hydrolysis of the serine ester substrate catalysed by bromelain and by papain. PMID:4455211

Reduction of Electric Breakdown Voltage in LC Switching Shutters / Elektriskās Caursites Sprieguma Samazināšana Šķidro Kristālu Šūnās

NASA Astrophysics Data System (ADS)

Mozolevskis, G.; Ozols, A.; Nitiss, E.; Linina, E.; Tokmakov, A.; Rutkis, M.

2015-10-01

ātes dēļ ir liela varbūtība šķidro kristālu (LC) šūnā novērot elektrisko caursiti, kuras laikā LC šūna tiek sabojāta. Šis ir viens no galvenajiem iemesliem, kāpēc šāda tipa ekrāni pagaidām vēl nav komerciāli plaši pieejami. Šajā darbā mēs skaidrojam rezultātus, kas iegūti, veicot LC šūnu caursites pētījumus. Elektrisko caursiti LC šūnā novēro brīdī, kad strāva tajā pārsniedz noteiktu sliekšņa vērtību. Strāvas stipruma sliekšņa vērtību nosaka šķidrā kristāla īpatnējā vadītspējā, kā arī punktu defekti LC šūnā, piemēram, putekļi, elektrodu raupjums, caurumi u.c. Strāvas stipruma ierobežošanai šūnā šajā darbā tika izmantotas dažādas metodes - buferslāņu iekļaušana, elektroda izlīdzinošā slāņa iekļaušana, kā arī elektroda sadalīšana ar lāzera ablācijas metodi. Tiek demonstrēts, ka elektrisko lauku, pie kura novēro caursiti šūnās, ir iespējams būtiski palielināt, šūnā iekļaujot elektriskos izolējošus buferslāņus un sadalot elektrodu.

Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

NASA Astrophysics Data System (ADS)

Yi, Liang; Chen, Yanping

2013-04-01

marine surface and core samples, and to quantitatively reconstruct sea-level variation since the late Pleistocene in the south Bohai Sea, China. New insights into regional relative sea-level changes since the late Pleistocene are obtained (Yi et al., 2012): (1) The grain size of surface and core samples can be mathematically partitioned using the Weibull distribution into four components. These four components with differing modal sizes and percentages could be interpreted as a long-term suspension component, which only settles under low turbulence conditions, sortable silt and very fine sand components transported by suspension during greater turbulence and bedload transport component, respectively. (2) Through regression and rigorous verification techniques, the reference water level could be reconstructed from sediment grain size. The reconstruction quantitatively extends the regional relative sea-level history to the late Pleistocene, providing a comparatively long dataset to evaluate regional sea-level variability. (3) We find no evidence of a sea-level high stand during MIS3 but rather a substantial regression during 70-30 cal kyr BP and potentially exposed land during 38-20 cal kyr BP. These results for the south Bohai Sea are in good agreement with published global sea-level records for the late Pleistocene, implying similarities between local and global sea-level patterns. Therefore, it is concluded that grain-size based sea-level reconstruction provide results that are comparable to other reconstruction methods and demonstrates great potential application for future works. (The data was shared on http://hurricane.ncdc.noaa.gov/) References Chappell, J., Omura, A., Esat, T., McCulloch, M., Pandolfi, J., Ota, Y., Pillans, B., 1996. Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records. Earth and Planetary Science Letters 141, 227-236. Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes

Determination of Two-Liquid Mixture Composition by Assessing Dielectric Parameters 1. Precise Measuring System / Divu Šķidrumu Maisījuma Sastāva Noteikšana, Izvērtējot to Dielektriskos Parametrus 1. Precīza Mērīšanas Sistēma

NASA Astrophysics Data System (ADS)

Vilitis, O.; Shipkovs, P.; Merkulovs, D.

2013-08-01

,01%. Šajā darbā piedāvātajā jaunajā mērīšanas sistēmas struktūras risinājumā iekļautas divas tiešas signālu digitālās sintēzes mikrosistēmas, kas ar augstu precizitāti ģenerē mērīšanai nepieciešamās formas, fāzes un amplitūdas signālus ar 100,000 kHz frekvenci un tiek vadītas no mikrokontrolera. Mērīšanas sistēmā izmantota mērsignālu sinhronizētās detektēšanas tehnika. Izstrādātās sistēmas konigurācija, mērīšanas režīma uzstādījums un vadība automātiski praktiski izslēdz virkni mērīšanas signālu parazītisko fāzes nobīžu un fāzes uzstādījumu kļūdas. Izstrādātā mērīšanas sistēma ērti piemērojama vispārējai izmantošanai kapacitātes vai impedances mērierīcēs. Samērā nelielā prognozējamā mērīšanas sistēmas pašizmaksa un kompaktā, portatīvā konstrukcija, kā arī iepriekš minētās priekšrocības paplašina sistēmas lietojumu ne tikai etanola koncentrācijas mērīanai bioetanola ražošanas procesā, bet šī sistēma var tikt izmantota arī eļļas, benzīna un citu degvielu testēšanai, ķīmiskajā, farmācijas un pārtikas industrijā, mikrobioloģijā un medicīnā, lai noteiktu glikozes, antigēnu, antivielu, proteīna, DNS fragmentu un citu vielu saturu šķīdumos u.c.

Reconciling late Quaternary transgressions in the Bohai Sea, China to the global sea level changes, and new linkage of sedimentary records to three astronomical rhythms

NASA Astrophysics Data System (ADS)

Yi, Liang

2013-04-01

noticeable feature of these coastal sediment variations is the little internal similarity between records compared with high similarity with external forcing indicating that the coastal sediments in the south Bohai Sea integrate different influences from various environmental factors: (1) the grain-size variation represents Asian monsoon intensity which was dominated by both solar insolation (major) and global ice volume (minor) forcing; (2) the magnetic susceptibility indicates river incision processes which were sensitive to orbital tilt with influence from solar insolation; (3) the vegetation coverage responded to global ice volume coupled obliquity changes; and that (4) neither external nor internal factors could dominate the paleoenvironmental evolution on orbital timescales in an independent way, and they are both integrated in a complex pattern. Therefore, combining all of these results, we report those great similarities between regional and global sea-level patterns and the nonlinear interaction and the complex response to driving processes in a coastal evolution. However, all of these studies only used the upper part of cores within marine strata, and the rest containing lacustrine sediment is still in process. Sediment grain size, magnetic susceptibility, color reflectance were finished, and the magnetostratigraphic, environmental magnetism and element analysis are ongoing. More results about high-/low-latitude interaction and relative sea level will be released in three years, and anyone who has interests in cooperation will be welcome (Email: yi.liang82@gmail.com). References Chappell, J., Omura, A., Esat, T., McCulloch, M., Pandolfi, J., Ota, Y., Pillans, B., 1996. Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records. Earth and Planetary Science Letters 141, 227-236. Cheng, H., Edwards, R.L., Broecker, W.S., Denton, G.H., Kong, X., Wang, Y., Zhang, R., Wang, X., 2009. Ice Age

PREFACE: Liquid-solid interfaces: structure and dynamics from spectroscopy and simulations Liquid-solid interfaces: structure and dynamics from spectroscopy and simulations

NASA Astrophysics Data System (ADS)

Gaigeot, Marie-Pierre; Sulpizi, Marialore

2012-03-01

energy electron diffraction (LEED), He atom scattering (HAS) and STM, to investigate the organization of water on metal, namely Pd(111) and Pt(111). Direct measurements of hyperpolarizabilities for non-linear spectroscopy can be made through hyper-Rayleigh scattering experiments, which are presented here by the group of P F Brevet on gold and silver nanoparticles. From the point of view of molecular dynamics simulations of interfaces, complementary levels of calculations are presented in this special section. The groups of K Leung, M-P Gaigeot, M Sulpizi and M Sprik provide theoretical investigations with DFT-based molecular dynamics simulations. Leung et al and Gaigeot et al address the hot topic issue of the reactivity of oxides surface sites and especially reliable methods to calculate pKas of these sites, with simulations taking into account both the solid and the liquid explicitly, and at the same first principles level of theory. Gaigeot, Sprik and Sulpizi furthermore combine the information on the structural organization of liquid water at the interface with quartz and alumina via pKa calculations and vibrational features (and their microscopic assignments). Mixed quantum/classical molecular dynamics (QM/MM) simulations are presented by Ishiyama and Morita for the investigation of another topical interface, i.e. the liquid-air interface. They provide the theoretical VSFG spectrum of the water-vapor interface and some understanding at the microscopic level of the experimental vibrational features. Molecular dynamics simulations based on empirical force fields have been applied to investigate hydrophobic interfaces by the groups of B Space and P Carloni. Carloni et al address salt effects at water-hydrophobic interfaces, investigating how the salts affect the structural organization of water at these interfaces. Space et al provide theoretical approximations to VSFG calculations in the special case of the carbon tetrachloride-water interface and the assignments of