22 research outputs found

    SYNTHESIS OF COPPER OXIDE NANOPARTICLES BY CHEMICAL PRECIPITATION METHOD FOR THE DETERMINATION OF ANTIBACTERIAL EFFICACY AGAINST STREPTOCOCCUS SP. AND STAPHYLOCOCCUS SP.

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    Objective: To determine antimicrobial efficacy of copper oxide nanoparticles (CuO NPs) against Streptococcus sp. and Staphylococcus sp. Methods: CuO NPs were synthesized using chemical precipitation method. The reducing agent, 0.1 M NaOH, was used along with 100 mM CuSO4 precursor for the synthesis of CuO NPs. The characterization of CuO NPs was done by ultraviolet-visible spectroscopy and scanning electron microscopy (SEM) to study optical and morphological characteristics, correspondingly. The identification of bacterial cultures was done through microscopic and biochemical studies. Antibacterial efficacy of CuO NPs was determined against Streptococcus sp. and Staphylococcus sp. by qualitative and quantitative methods through anti-well diffusion assay and broth dilution method, respectively. Results: The absorption spectrum and band gap were found to be at 260 nm and 4.77 eV, respectively. The SEM image of CuO NPs shows cluster of nanostructures having width of individual clusters in the range of 100 nm–500 nm. CuO NPs showed inhibition at a concentration ranging from 60 μg/mL to 1000 μg/mL. Conclusion: Finally, CuO NPs can be used as effective antibacterial agent against Streptococcus sp. and Staphylococcus sp. and may have applications in medical microbiology

    The accuracy of coronary CT angiography in patients with coronary calcium score above 1000 Agatston Units:Comparison with quantitative coronary angiography: Coronary CT Angiography in High Coronary Calcium

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    BACKGROUND: High amounts of coronary artery calcium (CAC) pose challenges in interpretation of coronary CT angiography (CCTA). The accuracy of stenosis assessment by CCTA in patients with very extensive CAC is uncertain. METHODS: Retrospective study was performed including patients who underwent clinically directed CCTA with CAC score >1000 and invasive coronary angiography within 90 days. Segmental stenosis on CCTA was graded by visual inspection with two-observer consensus using categories of 0%, 1–24%, 25–49%, 50–69%, 70–99%, 100% stenosis, or uninterpretable. Blinded quantitative coronary angiography (QCA) was performed on all segments with stenosis ≥25% by CCTA. The primary outcome was vessel-based agreement between CCTA and QCA, using significant stenosis defined by diameter stenosis ≥ 70%. Secondary analyses on a per-patient basis and inclusive of uninterpretable segments were performed. RESULTS: 726 segments with stenosis ≥25% in 346 vessels within 119 patients were analyzed. Median coronary calcium score was 1616 (1221–2118). CCTA identification of QCA-based stenosis resulted in a per-vessel sensitivity of 79%, specificity of 75%, positive predictive value (PPV) of 45%, negative predictive value (NPV) of 93%, and accuracy 76% (68 false positive and 15 false negative). Per-patient analysis had sensitivity 94%, specificity 55%, PPV 63%, NPV 92%, and accuracy 72% (30 false-positive and 3 false-negative). Inclusion of uninterpretable segments had variable effect on sensitivity and specificity, depending on whether they are considered as significant or non-significant stenosis. CONCLUSIONS: In patients with very extensive CAC (>1000 Agatston units), CCTA retained a negative predictive value > 90% to identify lack of significant stenosis on a per-vessel and per-patient level, but frequently overestimated stenosis

    Hypoxia-Inducible Factor 1α Signaling Promotes Repair of the Alveolar Epithelium after Acute Lung Injury

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    During the acute respiratory distress syndrome, epithelial cells, primarily alveolar type (AT) I cells, die and slough off, resulting in enhanced permeability. ATII cells proliferate and spread onto the denuded basement membrane to reseal the barrier. Repair of the alveolar epithelium is critical for clinical recovery; however, mechanisms underlying ATII cell proliferation and spreading are not well understood. We hypothesized that hypoxia-inducible factor (HIF)1α promotes proliferation and spreading of ATII cells during repair after lung injury. Mice were treated with lipopolysaccharide or hydrochloric acid. HIF activation in ATII cells after injury was demonstrated by increased luciferase activity in oxygen degradation domain-Luc (HIF reporter) mice and expression of the HIF1α target gene GLUT1. ATII cell proliferation during repair was attenuated in ATII cell-specific HIF1α knockout (SftpcCreERT2+/-;HIF1αf/f) mice. The HIF target vascular endothelial growth factor promoted ATII cell proliferation in vitro and after lung injury in vivo. In the scratch wound assay of cell spreading, HIF stabilization accelerated, whereas HIF1α shRNA delayed wound closure. SDF1 and its receptor, CXCR4, were found to be HIF1α-regulated genes in ATII cells and were up-regulated during lung injury. Stromal cell-derived factor 1/CXCR4 inhibition impaired cell spreading and delayed the resolution of permeability after lung injury. We conclude that HIF1α is activated in ATII cells after lung injury and promotes proliferation and spreading during repair

    Anticancer activity of VDR-coregulator inhibitor PS121912

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    PURPOSE: PS121912 has been developed as selective vitamin D receptor (VDR)–coregulator inhibitor starting from a high throughput screening campaign to identify new agents that modulate VDR without causing hypercalcemia. Initial antiproliferative effects of PS121912 were observed that are characterized herein to enable future in vivo investigation with this molecule. METHODS: Antiproliferation and apoptosis was determined using four different cancer cell lines (DU145, Caco2, HL-60, and SKOV3) in the presence of PS121912, 1,25-(OH)(2)D(3), or a combination of 1,25-(OH)(2)D(3) and PS121912. VDR si-RNA was used to identify the role of VDR during this process. The application of ChIP enabled us to determine the involvement of coregulator recruitment during transcription, which was investigated by rt-PCR with VDR target genes and those affiliated with cell cycle progression. Translational changes of apoptotic proteins were determined with an antibody array. The preclinical characterization of PS121912 include the determination of metabolic stability and CYP3A4 inhibition. RESULTS: PS121912 induced apoptosis in all four cancer cells, with HL-60 cells being the most sensitive. At sub-micromolar concentrations, PS121912 amplified the growth inhibition of cancer cells caused by 1,25-(OH)(2)D(3) without being antiproliferative by itself. A knockout study with VDR si-RNA confirmed the mediating role of VDR. VDR target genes induced by 1,25-(OH)(2)D(3) were down-regulated with the co-treatment of PS121912. This process was highly dependent on the recruitment of coregulators that in case of CYP24A1 was SRC2. The combination of PS121912 and 1,25-(OH)(2)D(3) reduced the presence of SRC2 and enriched the occupancy of corepressor NCoR at the promoter site. E2F transcription factor 1 and 4 were down-regulated in the presence of PS121912 and 1,25-(OH)(2)D(3) that in turn reduced the transcription levels of cyclin A and D thus arresting HL-60 cells in the S or G2/M phase. In addition, proteins with hematopietic functions such as cyclin-dependent kinase 6, histone deacetylase 9 and transforming growth factor beta 2 and 3 were down-regulated as well. Elevated levels of P21 and GADD45, in concert with cyclin D1 also mediated the antiproliferative response of HL-60 in the presence of 1,25-(OH)(2)D(3) and PS121912. Studies at higher concentration of P121912 identified a VDR-independent pathway of antiproliferation that included the enzymatic and transcriptional activation of caspase 3/7. CONCLUSION: Overall, we conclude that PS121912 behaves like a VDR antagonist at low concentrations but interacts with more targets at higher concentrations leading to apoptosis mediated by caspase 3/7 activation. In addition, PS121912 showed an acceptable metabolic stability to enable in vivo cancer studies
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