271 research outputs found

    The role of the ubiquitination-proteasome pathway in breast cancer: Applying drugs that affect the ubiquitin-proteasome pathway to the therapy of breast cancer

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    The ubiquitin-proteasome pathway is responsible for most eukaryotic intracellular protein degradation. This pathway has been validated as a target for antineoplastic therapy using both in vitro and preclinical models of human malignancies, and is influenced as part of the mechanism of action of certain chemotherapeutic agents. Drugs whose primary action involves modulation of ubiquitin-proteasome activity, most notably the proteasome inhibitor PS-341, are currently being evaluated in clinical trials, and have already been found to have significant antitumor efficacy. On the basis of the known mechanisms by which these agents work, and the available clinical data, they would seem to be well suited for the treatment of breast neoplasms. Such drugs, alone and especially in combination with current chemotherapeutics, may well represent important advances in the therapy of patients with breast cancer

    Preliminary Outcomes 1 Year after Laparoscopic Sleeve Gastrectomy Based on Bariatric Analysis and Reporting Outcome System (BAROS)

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    # The Author(s) 2011. This article is published with open access at Springerlink.com Background The aim of this study was to assess outcomes of laparoscopic sleeve gastrectomy (LSG) as a stand-alone bariatric operation according to the Bariatric Analysis and Reporting Outcome System (BAROS). Methods Out of 112 patients included and operated on initially, 84 patients (F/M, 63:21) were followed up for 14– 56 months (mean 22±6.75). Patients lost to follow-up did not attend scheduled follow-up visits or they have withdrawn their consent. Mean age was 39 years (range 17–67; SD±12.09) with mean initial BMI 44.62 kg/m 2 (range 29.39–82.8; SD±8.17). Statistical significance was established at the p<0.05 level. Results Mean operative time was 61 min (30–140 min) with mean hospital stay of 1.37 days (0–4; SD±0.77). Excellent global BAROS outcome was achieved in 13 % of patients, very good in 30%, good in 34.5%, fair 9.5 % and failure in 13 % patients 12 months after surgery. Females achieved significantly better outcomes than males with the mean 46.5 % of excess weight loss (EWL) versus 35.3 % of EWL at 12 months (p=0.02). The mean percentage of excess weight loss (%EWL) was 43.6 % at 12 months and 46.6 % at 24 months. Major surgical complication rate was 7.1%; minor surgical complication rate 8.3%. There was one conversion (1.2%) due to the massive bleeding. Comorbidities improved or resolved in numerous patients

    Polymorphisms in the multiple drug resistance protein 1 and in P-glycoprotein 1 are associated with time to event outcomes in patients with advanced multiple myeloma treated with bortezomib and pegylated liposomal doxorubicin

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    Single nucleotide polymorphisms (SNPs) in the multiple drug resistance protein 1 (MRP1) and P-glycoprotein 1 (MDR1) genes modulate their ability to mediate drug resistance. We therefore sought to retrospectively evaluate their influence on outcomes in relapsed and/or refractory myeloma patients treated with bortezomib or bortezomib with pegylated liposomal doxorubicin (PLD). The MRP1/R723Q polymorphism was found in five subjects among the 279 patient study population, all of whom received PLD + bortezomib. Its presence was associated with a longer time to progression (TTP; median 330 vs. 129 days; p = 0.0008), progression-free survival (PFS; median 338 vs. 129 days; p = 0.0006), and overall survival (p = 0.0045). MDR1/3435(C > T), which was in Hardy–Weinberg equilibrium, showed a trend of association with PFS (p = 0.0578), response rate (p = 0.0782) and TTP (p = 0.0923) in PLD + bortezomib patients, though no correlation was found in the bortezomib arm. In a recessive genetic model, MDR1/3435 T was significantly associated with a better TTP (p = 0.0405) and PFS (p = 0.0186) in PLD + bortezomib patients. These findings suggest a potential role for MRP1 and MDR1 SNPs in modulating the long-term outcome of relapsed and/or refractory myeloma patients treated with PLD + bortezomib. Moreover, they support prospective studies to determine if such data could be used to tailor therapy to the genetic makeup of individual patients

    Stable-isotope techniques to investigate sources of plant water

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    Stable isotopologues of water (mainly 1H216O, HD16O and 1H218O) have been used for decades as tracers of the Earth's water cycle. In this chapter, we briefly describe the theoretical background and state-of-the-art techniques of the use of water stable isotopes to investigate the sources of plant water. We aim to provide the basic understanding of stable isotope fractionation within the Earth's critical zone that is relevant for studies of plant water sources. We then present a practical guide of their most common applications in field studies and the most common and up-to-date laboratory procedures. We finally introduce the existing statistical approaches for estimating the relative contributions of water sources to plant transpiration. By acknowledging the advantages and limitations of each approach, we aim to provide an overview of the current techniques to researchers in the fields of plant ecophysiology, ecohydrology and forest ecology, so that they can make informed decisions when designing their experiments

    Tissue Transglutaminase Promotes Drug Resistance and Invasion by Inducing Mesenchymal Transition in Mammary Epithelial Cells

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    Recent observations that aberrant expression of tissue transglutaminase (TG2) promotes growth, survival, and metastasis of multiple tumor types is of great significance and could yield novel therapeutic targets for improved patient outcomes. To accomplish this, a clear understanding of how TG2 contributes to these phenotypes is essential. Using mammary epithelial cell lines (MCF10A, MCF12A, MCF7 and MCF7/RT) as a model system, we determined the impact of TG2 expression on cell growth, cell survival, invasion, and differentiation. Our results show that TG2 expression promotes drug resistance and invasive functions by inducing epithelial-mesenchymal transition (EMT). Thus, TG2 expression supported anchorage-independent growth of mammary epithelial cells in soft-agar, disrupted the apical-basal polarity, and resulted in disorganized acini structures when grown in 3D-culture. At molecular level, TG2 expression resulted in loss of E-cadherin and increased the expression of various transcriptional repressors (Snail1, Zeb1, Zeb2 and Twist1). Tumor growth factor-beta (TGF-β) failed to induce EMT in cells lacking TG2 expression, suggesting that TG2 is a downstream effector of TGF-β-induced EMT. Moreover, TG2 expression induced stem cell-like phenotype in mammary epithelial cells as revealed by enrichment of CD44+/CD24-/low cell populations. Overall, our studies show that aberrant expression of TG2 is sufficient for inducing EMT in epithelial cells and establish a strong link between TG2 expression and progression of metastatic breast disease

    A cross-sectional evidence-based review of pharmaceutical promotional marketing brochures and their underlying studies: Is what they tell us important and true?

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    BACKGROUND: A major marketing technique used by pharmaceutical companies is direct-to-physician marketing. This form of marketing frequently employs promotional marketing brochures, based on clinical research, which may influence how a physician prescribes medicines. This study's objective was to investigate whether or not the information in promotional brochures presented to physicians by pharmaceutical representatives is accurate, consistent, and valid with respect to the actual studies upon which the promotional brochures are based. METHODS: Physicians in five clinics were asked to consecutively collect pharmaceutical promotional brochures and to send them all to a centralized location. The brochures for any class of medication were collected on a continuous basis until 20 distinct promotional brochures were received by a central location. Once the brochure was received, the corresponding original study was obtained. Two blinded reviewers performed an evidence-based review of the article, comparing data that was printed on the brochure to what was found in the original study. RESULTS: Among the 20 studies, 75% of the studies were found to be valid, 80% were funded by the pharmaceutical company, 60% of the studies and the corresponding brochures presented patient-oriented outcomes, and 40% were compared to another treatment regimen. Of the 19 brochures that presented the data as graphs, 4 brochures presented a relative risk reduction while only 1 brochure presented an absolute risk reduction. 15% of the promotional marketing brochures presented data that was different from what was in the original published study. CONCLUSION: Given the present findings, physicians should be cautious about drawing conclusions regarding a medication based on the marketing brochures provided by pharmaceutical companies

    Mild hypothermia delays the development of stone heart from untreated sustained ventricular fibrillation - a cardiovascular magnetic resonance study

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    <p>Abstract</p> <p>Background</p> <p>'Stone heart' resulting from ischemic contracture of the myocardium, precludes successful resuscitation from ventricular fibrillation (VF). We hypothesized that mild hypothermia might slow the progression to stone heart.</p> <p>Methods</p> <p>Fourteen swine (27 ± 1 kg) were randomized to normothermia (group I; n = 6) or hypothermia groups (group II; n = 8). Mild hypothermia (34 ± 2°C) was induced with ice packs prior to VF induction. The LV and right ventricular (RV) cross-sectional areas were followed by cardiovascular magnetic resonance until the development of stone heart. A commercial 1.5T GE Signa NV-CV/i scanner was used. Complete anatomic coverage of the heart was acquired using a steady-state free precession (SSFP) pulse sequence gated at baseline prior to VF onset. Un-gated SSFP images were obtained serially after VF induction. The ventricular endocardium was manually traced and LV and RV volumes were calculated at each time point.</p> <p>Results</p> <p>In group I, the LV was dilated compared to baseline at 5 minutes after VF and this remained for 20 minutes. Stone heart, arbitrarily defined as LV volume <1/3 of baseline at the onset of VF, occurred at 29 ± 3 minutes. In group II, there was less early dilation of the LV (p < 0.05) and the development of stone heart was delayed to 52 ± 4 minutes after onset of VF (P < 0.001).</p> <p>Conclusions</p> <p>In this closed-chest swine model of prolonged untreated VF, hypothermia reduced the early LV dilatation and importantly, delayed the onset of stone heart thereby extending a known, morphologic limit of resuscitability.</p

    Down-Regulation of EBV-LMP1 Radio-Sensitizes Nasal Pharyngeal Carcinoma Cells via NF-κB Regulated ATM Expression

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    BACKGROUND:The latent membrane protein 1 (LMP1) encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. In previous studies we experimentally demonstrated that down-regulation of LMP1 expression by DNAzymes could increase radiosensitivity both in cells and in a xenograft NPC model in mice. RESULTS:In this study we explored the molecular mechanisms underlying the radiosensitization caused by the down-regulation of LMP1 in nasopharyngeal carcinoma. It was confirmed that LMP1 could up-regulate ATM expression in NPCs. Bioinformatic analysis of the ATM ptomoter region revealed three tentative binding sites for NF-κB. By using a specific inhibitor of NF-κB signaling and the dominant negative mutant of IkappaB, it was shown that the ATM expression in CNE1-LMP1 cells could be efficiently suppressed. Inhibition of LMP1 expression by the DNAzyme led to attenuation of the NF-κB DNA binding activity. We further showed that the silence of ATM expression by ATM-targeted siRNA could enhance the radiosensitivity in LMP1 positive NPC cells. CONCLUSIONS:Together, our results indicate that ATM expression can be regulated by LMP1 via the NF-κB pathways through direct promoter binding, which resulted in the change of radiosensitivity in NPCs
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