9 research outputs found

    Human palatine tonsil: a new potential tissue source of multipotent mesenchymal progenitor cells

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    INTRODUCTION: Mesenchymal progenitor cells (MPCs) are multipotent progenitor cells in adult tissues, for example, bone marrow (BM). Current challenges of clinical application of BM-derived MPCs include donor site morbidity and pain as well as low cell yields associated with an age-related decrease in cell number and differentiation potential, underscoring the need to identify alternative sources of MPCs. Recently, MPC sources have diversified; examples include adipose, placenta, umbilicus, trabecular bone, cartilage, and synovial tissue. In the present work, we report the presence of MPCs in human tonsillar tissue. ----- METHODS: We performed comparative and quantitative analyses of BM-MPCs with a subpopulation of adherent cells isolated from this lymphoid tissue, termed tonsil-derived MPCs (T-MPCs). The expression of surface markers was assessed by fluorescent-activated cell sorting analysis. Differentiation potential of T-MPCs was analyzed histochemically and by reverse transcription-polymerase chain reaction for the expression of lineage-related marker genes. The immunosuppressive properties of MPCs were determined in vitro in mixed lymphocyte reactions. ----- RESULTS: Surface epitope analysis revealed that T-MPCs were negative for CD14, CD31, CD34, and CD45 expression and positive for CD29, CD44, CD90, and CD105 expression, a characteristic phenotype of BM-MPCs. Similar to BM-MPCs, T-MPCs could be induced to undergo adipogenic differentiation and, to a lesser extent, osteogenic and chondrogenic differentiation. T-MPCs did not express class II major histocompatibility (MHC) antigens, and in a similar but less pronounced manner compared with BM-MPCs, T-MPCs were immunosuppressive, inhibiting the proliferation of T cells stimulated by allogeneic T cells or by non-specific mitogenic stimuli via an indoleamine 2,3-dioxygenase-dependent mechanism. ----- CONCLUSION: Human palatine T-MPCs represent a new source of progenitor cells, potentially applicable for cell-based therapies

    Effect of Grain Size on the Microwave Dielectric Characteristics of High-Energy Ball-Milled Zinc Magnesium Titanate Ceramics

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    Using solid-state reaction route and high-energy ball milling technique Zn1−xMgxTiO3 (x = 0–0.5) compositions were synthesized. These ball milled samples were sintered at 1100°C for 2 h and microwave dielectric properties such as dielectric constant (ε’), quality factor (Q) and temperature coefficient of resonant frequency (τf) were studied. Significant improvement in quality factor of ∼ 65% was observed for x = 0.3. To understand the effect of sintering duration on the microwave dielectric properties, single phase Zn0.7Mg0.3TiO3 samples were sintered at 1100°C for different durations from 2 to 20 h. The grain size increases with sintering duration and it influences to enhance the microwave dielectric properties and as a result, the quality factor further improved by three times. The dielectric constant and temperature coefficient of resonant frequency showed a slight improvement of ∼ 10%–15% with sintering duration

    Effect of grain size on the microwave dielectric characteristics of high-energy ball-milled zinc magnesium titanate ceramics

    No full text
    Using solid-state reaction route and high-energy ball milling technique Zn1−xMgxTiO3 (x = 0–0.5) compositions were synthesized. These ball milled samples were sintered at 1100°C for 2 h and microwave dielectric properties such as dielectric constant (ε’), quality factor (Q) and temperature coefficient of resonant frequency (τf) were studied. Significant improvement in quality factor of ∼ 65% was observed for x = 0.3. To understand the effect of sintering duration on the microwave dielectric properties, single phase Zn0.7Mg0.3TiO3 samples were sintered at 1100°C for different durations from 2 to 20 h. The grain size increases with sintering duration and it influences to enhance the microwave dielectric properties and as a result, the quality factor further improved by three times. The dielectric constant and temperature coefficient of resonant frequency showed a slight improvement of ∼ 10%–15% with sintering duration

    Effect of a Low-Fat Fish Oil Diet on Proinflammatory Eicosanoids and Cell-Cycle Progression Score in Men Undergoing Radical Prostatectomy

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    We previously reported that a 4-6 week low-fat fish oil (LFFO) diet did not affect serum IGF-1 levels (primary outcome) but resulted in lower omega-6 to omega-3 fatty acid ratios in prostate tissue and lower prostate cancer proliferation (Ki67) as compared to a Western diet (WD). In this post-hoc analysis, the effect of the LFFO intervention on serum pro-inflammatory eicosanoids, LTB4 and 15(S)-HETE, and the cell cycle progression (CCP) score were investigated. Serum fatty acids and eicosanoids were measured by gas chromatography and ELISA. CCP score was determined by RT-PCR. Associations between serum eicosanoids, Ki67, and CCP score were evaluated using partial correlation analyses. BLT1 (LTB4 receptor) expression was determined in prostate cancer cell lines and prostatectomy specimens. Serum omega-6 fatty acids and 15(S)-HETE levels were significantly reduced, and serum omega-3 levels were increased in the LFFO group relative to the WD group, whereas there was no change in LTB4 levels. The CCP score was significantly lower in the LFFO compared to the WD group. The 15(S)-HETE change correlated with tissue Ki67 (R=0.48; p<0.01) but not with CCP score. The LTB4 change correlated with the CCP score (r=0.4; p=0.02) but not with Ki67. The LTB4 receptor BLT1 was detected in prostate cancer cell lines and human prostate cancer specimens. In conclusion, a LFFO diet resulted in decreased 15(S)-HETE levels and lower CCP score relative to a WD. Further studies are warranted to determine whether the LFFO diet anti-proliferative effects are mediated through the LTB4/BLT1 and 15(S)-HETE pathways
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