509 research outputs found

    Osteocyte-Driven Downregulation of Snail Restrains Effects of Drd2 Inhibitors on Mammary Tumor Cells

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    While bone is a frequent target of breast cancer-associated metastasis, little is known about the effects of tumor-bone interactions on the efficacy of tumor-suppressing agents. Here we examined the effect of two FDA-approved dopamine modulators, fluphenazine and trifluoperazine, on mammary tumor cells, osteoclasts, osteoblasts, and osteocytes. These agents suppressed proliferation and migration of mammary tumor cells chiefly by antagonizing dopamine receptor D2 and reduced bone resorption by downregulating nuclear factor of activated T cells, cytoplasmic 1 (Nfatc1). Three-dimensional spheroid formation assays revealed that tumor cells have high affinity to osteocytes and type I collagen, and interactions with osteocytes as well as administration of fluphenazine and trifluoperazine downregulated Snail and suppressed migratory behaviors. Unlike the inhibitory action of fluphenazine and trifluoperazine on tumor growth, tumor-osteocyte interactions stimulated tumor proliferation by upregulating NFÎșB and Akt. In the bone microenvironment, osteocytes downregulated Snail and acted as an attractant as well as a stimulant to mammary tumor cells. These results demonstrate that tumor-osteocyte interactions strengthen dopamine receptor-mediated suppression of tumor migration but weaken its inhibition of tumor proliferation in the osteocyte-rich bone microenvironment.Significance: These findings provide novel insight into the cellular cross-talk in the bone microevironment and the effects of dopamine modulators on mammary tumor cells and osteocytes. Cancer Res; 78(14); 3865-76. ©2018 AACR

    Bcl-2 genes regulate noise-induced hearing loss

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    Proteins of the Bcl-2 family have been implicated in control of apoptotic pathways modulating neuronal cell death, including noise-induced hearing loss. In this study, we assessed the expressions of anti- and proapoptotic Bcl-2 genes, represented by Bcl-xL and Bak following noise exposures, which yielded temporary threshold shift (TTS) or permanent threshold shift (PTS). Auditory brainstem responses (ABRs) were assessed at 4, 8, and 16 kHz before exposure and on days 1, 3, 7, and 10 following exposure to 100 dB SPL, 4 kHz OBN, 1 hr (TTS) or 120 dB SPL, 4 kHz OBN, 5 hr (PTS). On day 10, subjects were euthanized. ABR thresholds increased following both exposures, fully recovered following the TTS exposure, and showed a 22.6 dB (4 kHz), 42.5 dB (8 kHz), and 44.9 dB (16 kHz) mean shift on day 10 following the PTS exposure. PTS was accompanied by outer hair cell loss progressing epically and basally from the 4-kHz region. Additional animals were euthanized for immunohistochemical assessment. BcL-xL was robustly expressed in outer hair cells following TTS exposure, whereas Bak was expressed following PTS exposure. These results indicate an important role of the Bcl-2 family proteins in regulating sensory cell survival or death following intense noise. Bcl-xL plays an essential role in prevention of sensory cell death following TTS levels of noise, and PTS exposure provokes the expression of Bak and, with that, cell death. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58028/1/21533_ftp.pd

    Metabolic Changes by Wine Flor-Yeasts with Gluconic Acid as the Sole Carbon Source

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    Gluconic acid consumption under controlled conditions by a Saccharomyces cerevisiae flor yeast was studied in artificial media. Gluconic acid was the sole carbon source and the compounds derived from this metabolism were tracked by endo-metabolomic analysis using a Gas Chromatography-Mass Spectrometry (GC-MSD) coupled methodology. After 6 days, about 30% of gluconic acid (1.5 g/L) had been consumed and 34 endo-metabolites were identified. Metabolomic pathway analysis showed the TCA cycle, glyoxylate-dicarboxylate, glycine-serine-threonine, and glycerolipid metabolic pathway were significantly affected. These results contribute to the knowledge of intracellular metabolomic fluctuations in flor yeasts during gluconic acid uptake, opening possibilities for future experiments to improve their applications to control gluconic acid contents during the production of fermented beverages

    Photon correlation in GaAs self-assembled quantum dots

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    We report on photon coincidence measurement in a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, when a neutral exciton line was present in the photoluminescence (PL) spectrum, we observed nearly perfect single photon emission from an isolated QD at 670 nm wavelength. For higher excitation, multiple PL lines appeared on the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexciton cascade or a charged exciton recombination.Comment: 5 pages, 3 figure

    Cellular HIV-1 DNA levels in patients receiving antiretroviral therapy strongly correlate with therapy initiation timing but not with therapy duration

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    <p>Abstract</p> <p>Background</p> <p>Viral reservoir size refers to cellular human immunodeficiency virus-1 (HIV-1) DNA levels in CD4<sup>+ </sup>T lymphocytes of peripheral blood obtained from patients with plasma HIV-1-RNA levels (viral load, VL) maintained below the detection limit by antiretroviral therapy (ART). We measured HIV-1 DNA levels in CD4<sup>+ </sup>lymphocytes in such patients to investigate their clinical significance.</p> <p>Methods</p> <p>CD4<sup>+ </sup>T lymphocytes were isolated from the peripheral blood of 61 patients with a VL maintained at less than 50 copies/ml for at least 4 months by ART and total DNA was purified. HIV-1 DNA was quantified by nested PCR to calculate the copy number per 1 million CD4<sup>+ </sup>lymphocytes (relative amount) and the copy number in 1 ml of blood (absolute amount). For statistical analysis, the Spearman rank or Wilcoxon signed-rank test was used, with a significance level of 5%.</p> <p>Results</p> <p>CD4 cell counts at the time of sampling negatively correlated with the relative amount of HIV-1 DNA (median = 33 copies/million CD4<sup>+ </sup>lymphocytes; interquartile range [IQR] = 7-123 copies/million CD4<sup>+ </sup>lymphocytes), but were not correlated with the absolute amounts (median = 17 copies/ml; IQR = 5-67 copies/ml). Both absolute and relative amounts of HIV-1 DNA were significantly lower in six patients in whom ART was initiated before positive seroconversion than in 55 patients in whom ART was initiated in the chronic phase, as shown by Western blotting. CD4 cell counts before ART introduction were also negatively correlated with both the relative and absolute amounts of HIV-1 DNA. Only the relative amounts of HIV-1 DNA negatively correlated with the duration of VL maintenance below the detection limit, while the absolute amounts were not significantly correlated with this period.</p> <p>Conclusions</p> <p>The amounts of cellular HIV-1 DNA in patients with VLs maintained below the detection limit by the introduction of ART correlated with the timing of ART initiation but not with the duration of ART. In addition, CD4<sup>+ </sup>T lymphocytes, which were newly generated by ART, diluted latently infected cells, indicating that measurements of the relative amounts of cellular HIV-1 DNA might be underestimated.</p

    Impact of Baseline ALBI Grade on the Outcomes of Hepatocellular Carcinoma Patients Treated with Lenvatinib: A Multicenter Study

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    Background: This study investigated the impact of baseline liver function according to the Child–Pugh score and ALBI (albumin-bilirubin) grade on the outcomes of patients with unresectable hepatocellular carcinoma treated with lenvatinib. Methods: A total of 82 lenvatinib treated patients were included. The correlations of baseline liver function according to the Child–Pugh score and ALBI grade with treatment outcomes, including objective response rate per mRECIST (modified Response Evaluation Criteria in the Solid Tumor), time to treatment failure, treatment duration, and likelihood of treatment discontinuation due to adverse events, were assessed in patients with hepatocellular carcinoma treated with lenvatinib. Patients were divided into four groups: (1) Child–Pugh score 5 and ALBI grade 1 (group 1), (2) Child–Pugh score 5 and ALBI grade 2 (group 2), (3) Child–Pugh score 6 (group 3), and (4) Child–Pugh score ≄7 (group 4). Univariate and multivariate analyses were performed to identify the factors contributing to the objective response rate and likelihood of discontinuation due to adverse events. Results: Among the 82 patients analyzed, group 1 had the highest objective response rate (57.1%) and the lowest likelihood of treatment discontinuation because of adverse events (11.1%) among the four groups (p &lt; 0.05 and p &lt; 0.05). Multivariate analysis identified ALBI grade 1 and baseline AFP level &lt;200 ng/mL as the significant predictors of a high objective response rate (p &lt; 0.05 and p &lt; 0.01), and confirmed that patients with ALBI grade 1 had the lowest probability of treatment discontinuation due to adverse events (p &lt; 0.01). Conclusions: Patients with Child–Pugh score of 5 and ALBI grade 1 predicted a higher response rate and lower treatment discontinuation due to adverse events by lenvatinib treatment
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