High-sensitive and rapid detection of Mycobacterium tuberculosis infection by IFN-γ release assay among HIV-infected individuals in BCG-vaccinated area

<p>Abstract</p> <p>Background</p> <p>An accurate test for <it>Mycobacterium tuberculosis </it>infection is urgently needed in immunosuppressed populations. The aim of this study was to investigate the diagnostic power of enzyme-linked immunospot (ELISPOT)-based IFN-γ release assay in detecting active and latent tuberculosis in HIV-infected population in <it>bacillus Calmette-Guerin </it>(BCG)-vaccinated area. A total of 100 HIV-infected individuals including 32 active tuberculosis patients were recruited. An ELISPOT-based IFN-γ release assay, T-SPOT.TB, was used to evaluate the <it>M. tuberculosis </it>ESAT-6 and CFP-10 specific IFN-γ response. Tuberculin skin test (TST) was performed for all recruited subjects.</p> <p>Results</p> <p>The subjects were divided into group HIV+ATB (HIV-infected individuals with active tuberculosis, n = 32), group HIV+LTB (HIV-infected individuals with positive results of T-SPOT.TB assay, n = 46) and group HIV only (HIV-infected individuals with negative results of T-SPOT.TB assay and without evidence of tuberculosis infection, n = 22). In group HIV+ATB and HIV+LTB, T-SPOT.TB positive rate in subjects with TST <5 mm were 50% (16/32) and 41.3% (19/46), respectively. Individuals in group HIV+ATB and HIV+LTB with CD4+ T cells <500/μl, T-SPOT.TB showed a higher sensitivity than TST (64.5% vs. 22.6% and 62.2% vs. 29.7%, respectively, both <it>P </it>< 0.0001). In addition, the sensitivity of T-SPOT.TB assay in group HIV+ATB increased to >85% in patients with TB treatment for less than 1 month and CD4+ T cells ≥200/μl, while for patients treated for more than 3 months and CD4+ T cells <200/μl, the sensitivity was decreased to only 33.3%. Furthermore, the results could be generated by T-SPOT.TB assay within 24 hours, which was more rapid than TST with 48–72 hours.</p> <p>Conclusion</p> <p>ELISPOT-based IFN-γ release assay is more sensitive and rapid for the diagnosis of TB infection in Chinese HIV-infected individuals with history of BCG vaccination, and could be an effective tool for guiding preventive treatment with isoniazid in latently infected people and for TB control in China.</p

First-principles study of electronic structures and optical properties of Cu, Ag, and Au-doped anatase TiO2

We perform first-principles calculations to investigate the band structure, density of states, optical absorption, and the imaginary part of dielectric function of Cu, Ag, and Au-doped anatase TiO2 in 72 atoms systems. The electronic structure results show that the Cu incorporation can lead to the enhancement of d states near the uppermost of valence band, while the Ag and Au doping cause some new electronic states in band gap of TiO2. Meanwhile, it is found that the visible optical absorptions of Cu, Ag, and Au-doped TiO2, are observed by analyzing the results of optical properties,.which locate in the region of 400-1000 nm. The absorption band edges of Cu, Ag, and Au-doped TiO2 shift to the long wavelength region compared with the pure TiO2. Furthermore, according to the calculated results, we propose the optical transition mechanisms of Cu, Ag, and Au-doped TiO2, respectively. Our results show that the visible light response of TiO2 can be modulated by substitutional doping of Cu, Ag, and Au.Comment: 12 pages, 6 figures, 43 reference

Inhibitory effect of genistein on the invasive potential of human cervical cancer cells via modulation of matrix metalloproteinase-9 and tissue inhibitiors of matrix metalloproteinase-1 expression

Background: One of the most challenging stumbling blocks for the treatment of cancer is the ability of cancer cells to break the natural barriers and spread from its site of origin to non-adjacent regional and distant sites, accounting for high cancer mortality rates. Gamut experimental and epidemiological data advocate the use of pharmacological or nutritional interventions to inhibit or delay various stage(s) of cancer such as invasion and metastasis. Genistein, a promising chemopreventive agent, has gained considerable attention for its powerful anti-carcinogenic, anti-angiogenic and chemosensitizing activities. Methods: In this study, the cytotoxic potential of genistein on HeLa cells by cell viability assay and the mode of cell death induced by genistein were determined by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Moreover, to establish its inhibitory effect on migration of HeLa cells, scratch wound assay was performed and these results were correlated with the expression of genes involved in invasion and migration (MMP-9 and TIMP-1) by RT-PCR. Results: The exposure of HeLa cells to genistein resulted in significant dose- and time-dependent growth inhibition, which was found to be mediated by apoptosis and cell cycle arrest at G2/M phase. In addition, it induced migration-inhibition in a time-dependent manner by modulating the expression of MMP-9 and TIMP-1. Conclusion: Our results signify that genistein may be an effective anti-neoplastic agent to prevent cancer cell growth and invasion and metastasis. Therefore therapeutic strategies utilizing genistein could be developed to substantially reduce cancer morbidity and mortality. © 2012 Elsevier Ltd

Comparison of sterols and fatty acids in two species of Ganoderma

<p>Abstract</p> <p>Background</p> <p>Two species of <it>Ganoderma, G. sinense </it>and <it>G. lucidum</it>, are used as <it>Lingzhi </it>in China. Howerver, the content of triterpenoids and polysaccharides, main actives compounds, are significant different, though the extracts of both <it>G. lucidum </it>and <it>G. sinense </it>have antitumoral proliferation effect. It is suspected that other compounds contribute to their antitumoral activity. Sterols and fatty acids have obvious bioactivity. Therefore, determination and comparison of sterols and fatty acids is helpful to elucidate the active components of <it>Lingzhi</it>.</p> <p>Results</p> <p>Ergosterol, a specific component of fungal cell membrane, was rich in <it>G. lucidum </it>and <it>G. sinense</it>. But its content in <it>G. lucidum </it>(median content 705.0 μg·g^-1, range 189.1-1453.3 μg·g^-1, n = 19) was much higher than that in <it>G. sinense </it>(median content 80.1 μg·g^-1, range 16.0-409.8 μg·g^-1, n = 13). Hierarchical clustering analysis based on the content of ergosterol showed that 32 tested samples of <it>Ganoderma </it>were grouped into two main clusters, <it>G. lucidum </it>and <it>G. sinense</it>. Hierarchical clustering analysis based on the contents of ten fatty acids showed that two species of <it>Ganoderma </it>had no significant difference though two groups were also obtained. The similarity of two species of <it>Ganoderma </it>in fatty acids may be related to their antitumoral proliferation effect.</p> <p>Conclusions</p> <p>The content of ergosterol is much higher in <it>G. lucidum </it>than in <it>G. sinense</it>. Palmitic acid, linoleic acid, oleic acid, stearic acid are main fatty acids in <it>Ganoderma </it>and their content had no significant difference between <it>G. lucidum </it>and <it>G. sinense</it>, which may contribute to their antitumoral proliferation effect.</p

Genetic diversity and population structure of cucumber (Cucumis sativus L.)

Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop's genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR) markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber

Novel Biomarkers Distinguishing Active Tuberculosis from Latent Infection Identified by Gene Expression Profile of Peripheral Blood Mononuclear Cells

BACKGROUND: Humans infected with Mycobacterium tuberculosis (MTB) can delete the pathogen or otherwise become latent infection or active disease. However, the factors influencing the pathogen clearance and disease progression from latent infection are poorly understood. This study attempted to use a genome-wide transcriptome approach to identify immune factors associated with MTB infection and novel biomarkers that can distinguish active disease from latent infection. METHODOLOGY/PRINCIPAL FINDINGS: Using microarray analysis, we comprehensively determined the transcriptional difference in purified protein derivative (PPD) stimulated peripheral blood mononuclear cells (PBMCs) in 12 individuals divided into three groups: TB patients (TB), latent TB infection individuals (LTBI) and healthy controls (HC) (n = 4 per group). A transcriptional profiling of 506 differentially expressed genes could correctly group study individuals into three clusters. Moreover, 55- and 229-transcript signatures for tuberculosis infection (TB&LTBI) and active disease (TB) were identified, respectively. The validation study by quantitative real-time PCR (qPCR) performed in 83 individuals confirmed the expression patterns of 81% of the microarray identified genes. Decision tree analysis indicated that three genes of CXCL10, ATP10A and TLR6 could differentiate TB from LTBI subjects. Additional validation was performed to assess the diagnostic ability of the three biomarkers within 36 subjects, which yielded a sensitivity of 71% and specificity of 89%. CONCLUSIONS/SIGNIFICANCE: The transcription profiles of PBMCs induced by PPD identified distinctive gene expression patterns associated with different infectious status and provided new insights into human immune responses to MTB. Furthermore, this study indicated that a combination of CXCL10, ATP10A and TLR6 could be used as novel biomarkers for the discrimination of TB from LTBI