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Find video protocols related to scientific articles indexed in Pubmed.
CD4 T Cells Specific for a Latency-Associated ?-Herpesvirus Epitope Are Polyfunctional and Cytotoxic.
J. Immunol.
PUBLISHED: 11-08-2014
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The oncogenic ?-herpesviruses EBV and Kaposi sarcoma-associated herpesvirus are ubiquitous human pathogens that establish lifelong latent infections maintained by intermittent viral reactivation and reinfection. Effector CD4 T cells are critical for control of viral latency and in immune therapies for virus-associated tumors. In this study, we exploited ?HV68 infection of mice to enhance our understanding of the CD4 T cell response during ?-herpesvirus infection. Using a consensus prediction approach, we identified 16 new CD4 epitope-specific responses that arise during lytic infection. An additional epitope encoded by the M2 protein induced uniquely latency-associated CD4 T cells, which were not detected at the peak of lytic infection but only during latency and were not induced postinfection with a latency-deficient virus. M2-specific CD4 T cells were selectively cytotoxic, produced multiple antiviral cytokines, and sustained IL-2 production. Identification of latency-associated cytolytic CD4 T cells will aid in dissecting mechanisms of CD4 immune control of ?-herpesvirus latency and the development of therapeutic approaches to control viral reactivation and pathology.
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Urinary Metabolite Profiling Combined with Computational Analysis Predicts Interstitial Cystitis-Associated Candidate Biomarkers.
J. Proteome Res.
PUBLISHED: 10-30-2014
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Interstitial cystitis/painful bladder syndrome (IC) is a chronic syndrome of unknown etiology that presents with bladder pain, urinary frequency, and urgency. The lack of specific biomarkers and a poor understanding of underlying molecular mechanisms present challenges for disease diagnosis and therapy. The goals of this study were to identify noninvasive biomarker candidates for IC from urine specimens and to potentially gain new insight into disease mechanisms using a nuclear magnetic resonance (NMR)-based global metabolomics analysis of urine from female IC patients and controls. Principal component analysis (PCA) suggested that the urinary metabolome of IC and controls was clearly different, with 140 NMR peaks significantly altered in IC patients (FDR < 0.05) compared to that in controls. On the basis of strong correlation scores, fifteen metabolite peaks were nominated as the strongest signature of IC. Among those signals that were higher in the IC group, three peaks were annotated as tyramine, the pain-related neuromodulator. Two peaks were annotated as 2-oxoglutarate. Levels of tyramine and 2-oxoglutarate were significantly elevated in urine specimens of IC subjects. An independent analysis using mass spectrometry also showed significantly increased levels of tyramine and 2-oxoglutarate in IC patients compared to controls. Functional studies showed that 2-oxoglutarate, but not tyramine, retarded growth of normal bladder epithelial cells. These preliminary findings suggest that analysis of urine metabolites has promise in biomarker development in the context of IC.
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Exploring the role of conformational heterogeneity in cis-autoproteolytic activation of ThnT.
Biochemistry
PUBLISHED: 06-26-2014
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In the past decade, there have been major achievements in understanding the relationship between enzyme catalysis and protein structural plasticity. In autoprocessing systems, however, there is a sparsity of direct evidence of the role of conformational dynamics, which are complicated by their intrinsic chemical reactivity. ThnT is an autoproteolytically activated enzyme involved in the biosynthesis of the ?-lactam antibiotic thienamycin. Conservative mutation of ThnT results in multiple conformational states that can be observed via X-ray crystallography, establishing ThnT as a representative and revealing system for studing how conformational dynamics control autoactivation at a molecular level. Removal of the nucleophile by mutation to Ala disrupts the population of a reactive state and causes widespread structural changes from a conformation that promotes autoproteolysis to one associated with substrate catalysis. Finer probing of the active site polysterism was achieved by EtHg derivatization of the nucleophile, which indicates the active site and a neighboring loop have coupled dynamics. Disruption of these interactions by mutagenesis precludes the ability to observe a reactive state through X-ray crystallography, and application of this insight to other autoproteolytically activated enzymes offers an explanation for the widespread crystallization of inactive states. We suggest that the N?O(S) acyl shift in cis-autoproteolysis might occur through a si-face attack, thereby unifying the fundamental chemistry of these enzymes through a common mechanism.
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An overview of disparities and interventions in pediatric kidney transplantation worldwide.
Pediatr. Nephrol.
PUBLISHED: 06-04-2014
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Despite the stated goals of the transplant community and the majority of organ allocation systems, persistent racial disparities in pediatric kidney transplantation exist throughout the world. These disparities are evident in both living and deceased donor kidney transplantation and are independent of any clinical differences between racial groups. The reasons for these persistent disparities are multifactorial, reflecting both patient and provider barriers to care. In this review, we examine the most current findings regarding disparities in pediatric kidney transplantation and consider interventions which may help reduce those disparities.
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Efficacy of autologous bone marrow concentrate for knee osteoarthritis with and without adipose graft.
Biomed Res Int
PUBLISHED: 05-19-2014
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We investigated the use of autologous bone marrow concentrate (BMC) with and without an adipose graft, for treatment of knee osteoarthritis (OA).
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Integration of proteomic and transcriptomic profiles identifies a novel PDGF-MYC network in human smooth muscle cells.
Cell Commun. Signal
PUBLISHED: 05-14-2014
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BackgroundPlatelet-derived growth factor-BB (PDGF-BB) has been implicated in the proliferation, migration and synthetic activities of smooth muscle cells that characterize physiologic and pathologic tissue remodeling in hollow organs. However, neither the molecular basis of PDGFR-regulated signaling webs, nor the extent to which specific components within these networks could be exploited for therapeutic benefit has been fully elucidated.ResultsExpression profiling and quantitative proteomics analysis of PDGF-treated primary human bladder smooth muscle cells identified 1,695 genes and 241 proteins as differentially expressed versus non-treated cells. Analysis of gene expression data revealed MYC, JUN, EGR1, MYB, RUNX1, as the transcription factors most significantly networked with up-regulated genes. Forty targets were significantly altered at both the mRNA and protein levels. Proliferation, migration and angiogenesis were the biological processes most significantly associated with this signature, and MYC was the most highly networked master regulator. Alterations in master regulators and gene targets were validated in PDGF-stimulated smooth muscle cells in vitro and in a model of bladder injury in vivo. Pharmacologic inhibition of MYC and JUN confirmed their role in SMC proliferation and migration. Network analysis identified the diaphanous-related formin 3 as a novel PDGF target regulated by MYC and JUN, which was necessary for PDGF-stimulated lamellipodium formation.ConclusionsThese findings provide the first systems-level analysis of the PDGF-regulated transcriptome and proteome in normal smooth muscle cells. The analyses revealed an extensive cohort of PDGF-dependent biological processes and connected key transcriptional effectors to their regulation, significantly expanding current knowledge of PDGF-stimulated signaling cascades. These observations also implicate MYC as a novel target for pharmacological intervention in fibroproliferative expansion of smooth muscle, and potentially in cancers in which PDGFR-dependent signaling or MYC activation promote tumor progression.
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Promotion of a subdominant CD8 T cell response during murine gammaherpesvirus 68 infection in the absence of CD4 T cell help.
J. Virol.
PUBLISHED: 04-30-2014
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CD8 and CD4 T cells are each critically important for immune control of murine gammaherpesvirus 68 (?HV68) infection. In immunocompetent mice, acute ?HV68 infection results in lifelong latency, but in the absence of CD4 T cell help, mice succumb to viral recrudescence and disease. However, the requirements for CD4 T cell help in the generation and maintenance of antiviral CD8 T cell responses are incompletely understood, and it is unclear whether there are epitope-specific differences in the requirement of CD8 T cells for CD4 help. In this report, we characterized the CD8 T cell response to ?HV68 in major histocompatibility complex (MHC) class II(-/-) mice, which lack CD4 T cells, or after antibody-mediated depletion of CD4 T cells. All antiviral CD8 T cells exhibited marked upregulation of surface expression of the inhibitory receptor programmed death-1 (PD-1), but surprisingly, while the immunodominant memory response appeared to be functionally impaired, helpless CD8 T cells of a subdominant specificity had increased numbers and enhanced functionality. Thus, we demonstrate differential requirements for CD4 help in the antiviral CD8 T cell response to a latent gammaherpesvirus. Importance: ?HV68 is a mouse pathogen closely related to the oncogenic human ?HVs, which infect a majority of the world's population. Reactivation of these viruses from latency can lead to complications, disease, and even death. CD4 T cells are required for complete immune control of long-term infection, in part by providing key signals to dendritic cells that in turn instruct optimal antiviral CD8 T cell responses. We have investigated multiple virus-specific CD8 T cell responses during infection and identified a subdominant CD8 T cell response that is numerically and functionally enhanced in the absence of CD4 T cell help. This occurs in spite of high surface expression of an inhibitory receptor and in contrast to the immunodominant response, which is impaired. Our data suggest that signals from CD4 T cells are important in maintaining the CD8 T cell hierarchy during ?HV infections.
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Targeting nucleophosmin 1 represents a rational strategy for radiation sensitization.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 04-01-2014
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To test the hypothesis that small molecule targeting of nucleophosmin 1 (NPM1) represents a rational approach for radiosensitization.
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Injury pattern as an indication of seat belt failure in ejected vehicle occupants.
J. Forensic Sci.
PUBLISHED: 03-25-2014
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Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (?0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections.
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Autopsy practice in forensic pathology - evidence-based or experience-based? a review of autopsies performed on victims of traumatic asphyxia in a mass disaster.
J Forensic Leg Med
PUBLISHED: 02-04-2014
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Current autopsy practice in forensic pathology is to a large extent based on experience and individual customary practices as opposed to evidence and consensus based practices. As a result there is the potential for substantial variation in how knowledge is applied in each case. In the present case series, we describe the variation observed in autopsy reports by five different pathologists of eight victims who died simultaneously from traumatic asphyxia due to compression during a human stampede. We observed that there was no mention of the availability of medical charts in five of the reports, of potentially confounding resuscitation efforts in three reports, of cardinal signs in seven reports and of associated injuries to a various degree in all reports. Further, there was mention of supplemental histological examination in two reports and of pre-autopsy radiograph in six reports. We inferred that reliance on experience and individual customary practices led to disparities between the autopsy reports as well as omissions of important information such as cardinal signs, and conclude that such reliance increases the potential for error in autopsy practice. We suggest that pre-autopsy data-gathering and the use of check lists specific to certain injury causes are likely to result in less deviation from evidence-based practices in forensic pathology. Pre-autopsy data-gathering and check lists will help ensure a higher degree of standardization in autopsy reports thus enhancing the quality and accuracy of the report as a legal document as well as rendering it more useful for data-gathering efforts.
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Radical S-adenosyl methionine epimerases: regioselective introduction of diverse D-amino acid patterns into peptide natural products.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 01-16-2014
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PoyD is a radical S-adenosyl methionine epimerase that introduces multiple D-configured amino acids at alternating positions into the highly complex marine peptides polytheonamide A and B. This novel post-translational modification contributes to the ability of the polytheonamides to form unimolecular minimalistic ion channels and its cytotoxic activity at picomolar levels. Using a genome mining approach we have identified additional PoyD homologues in various bacteria. Three enzymes were expressed in E. coli with their cognate as well as engineered peptide precursors and shown to introduce diverse D-amino acid patterns into all-L peptides. The data reveal a family of architecturally and functionally distinct enzymes that exhibit high regioselectivity, substrate promiscuity, and irreversible action and thus provide attractive opportunities for peptide engineering.
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Enhanced shedding of extracellular vesicles from amoeboid prostate cancer cells: potential effects on the tumor microenvironment.
Cancer Biol. Ther.
PUBLISHED: 01-14-2014
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The gene encoding the cytoskeletal regulator DIAPH3 is lost at high frequency in metastatic prostate cancer, and DIAPH3 silencing evokes a transition to an amoeboid tumor phenotype in multiple cell backgrounds. This amoeboid transformation is accompanied by increased tumor cell migration, invasion, and metastasis. DIAPH3 silencing also promotes the formation of atypically large (> 1 ?m) membrane blebs that can be shed as extracellular vesicles (EV) containing bioactive cargo. Whether loss of DIAPH3 also stimulates the release of nano-sized EV (e.g., exosomes) is not established. Here we examined the mechanism of release and potential biological functions of EV shed from DIAPH3-silenced and other prostate cancer cells. We observed that stimulation of LNCaP cells with the prostate stroma-derived growth factor heparin-binding EGF-like growth factor (HB-EGF), combined with p38MAPK inhibition caused EV shedding, a process mediated by ERK1/2 hyperactivation. DIAPH3 silencing in DU145 cells also increased rates of EV production. EV isolated from DIAPH3-silenced cells activated AKT1 and androgen signaling, increased proliferation of recipient tumor cells, and suppressed proliferation of human macrophages and peripheral blood mononuclear cells. DU145 EV contained miR-125a, which suppressed AKT1 expression and proliferation in recipient human peripheral blood mononuclear cells and macrophages. Our findings suggest that EV produced as a result of DIAPH3 loss or growth factor stimulation may condition the tumor microenvironment through multiple mechanisms, including the proliferation of cancer cells and suppression of tumor-infiltrating immune cells.
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Extracellular vesicles shed from gefitinib-resistant nonsmall cell lung cancer regulate the tumor microenvironment.
Proteomics
PUBLISHED: 01-09-2014
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Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), including gefitinib, are the first-line treatment of choice for nonsmall cell lung cancer patients who harbor activating EGFR mutations, however, acquired resistance to EGFR-TKIs is inevitable. The main objective of this study was to identify informative protein signatures of extracellular vesicles (EV) derived from gefitinib-resistant nonsmall cell lung cancer cells using proteomics analysis. Nano-LC-MS/MS analysis identified with high confidence (false discovery rate < 0.05, fold change ?2) 664 EV proteins enriched in PC9R cells, which are resistant to gefitinib due to EGFR T790M mutation. Computational analyses suggested components of several signal transduction mechanisms including the AKT (also PKB, protein kinase B)/mTOR (mechanistic target of rapamycin) pathway are overrepresented in EV from PC9R cells. Treatment of recipient cells with EV harvested from PC9R cells increased phosphorylation of signaling molecules, and enhanced proliferation, invasion, and drug resistance to gefitinib-induced apoptosis. Dose- and time-dependent pharmaceutical inhibition of AKT/mTOR pathway overcame drug resistance of PC9R cells and those of H1975 exhibiting EGFR T790M mutation. Our findings provide new insight into an oncogenic EV protein signature regulating tumor microenvironment, and will aid in the development of novel diagnostic strategies for prediction and assessment of gefitinib resistance.
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Smoking prevalence and cigarette consumption in 187 countries, 1980-2012.
JAMA
PUBLISHED: 01-09-2014
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Tobacco is a leading global disease risk factor. Understanding national trends in prevalence and consumption is critical for prioritizing action and evaluating tobacco control progress.
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Low testosterone elevates interleukin family cytokines in a rodent model: a possible mechanism for the potentiation of vascular disease in androgen-deficient males.
J. Surg. Res.
PUBLISHED: 01-04-2014
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Androgen deficiency (AD) is associated with increased risk of atherosclerosis, cardiovascular, and peripheral arterial disease. Although the biochemical and molecular mechanisms underlying this risk remain unclear, higher testosterone (TST) levels correlate to significant immunoprotective molecular and cellular responses. Our group has previously demonstrated that female sex hormones influence vascular pathogenesis via inflammatory-modulated matrix metalloproteinase (MMP) regulation. Here we investigated the role of AD and androgen replacement therapy in the modulation of these hormonally responsive pathways that could be playing a role in the development of vascular pathogenesis.
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Comparative Immune Phenotypic Analysis of Cutaneous Squamous Cell Carcinoma and Intraepidermal Carcinoma in Immune-Competent Individuals: Proportional Representation of CD8+ T-Cells but Not FoxP3+ Regulatory T-Cells Is Associated with Disease Stage.
PLoS ONE
PUBLISHED: 01-01-2014
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Squamous Cell Carcinoma (SCC) is a type of non-melanoma skin cancer prevalent in immune-suppressed transplant recipients and older individuals with a history of chronic sun-exposure. SCC itself is believed to be a late-stage manifestation that can develop from premalignant lesions including Intraepidermal Carcinoma (IEC). Notably, while SCC regression is rare, IEC typically regresses in response to immune modifying topical treatments, however the underlying immunological reasons for these differential responses remain unclear. This study aimed to define whether IEC and SCC are associated with distinct immune profiles. We investigated the immune cell infiltrate of photo-damaged skin, IEC, and SCC tissue using 10-colour flow cytometry following fresh lesion digest. We found that IEC lesions contain higher percentages of CD3+ T-cells than photo-damaged skin, however, the abundance of CD3-CD56+ Natural Killer (NK) cells, CD11c+HLA-DR+ conventional Dendritic Cells (cDC), BDCA-2+HLA-DR+ plasmacytoid DC (pDC), FoxP3+ Regulatory T-cells (T-reg), V?24+V?11+ invariant NKT-cells, and ?? Tcells did not alter with disease stage. Within the total T-cell population, high percentages of CD4+ T-cells were associated with SCC, yet CD8+ T-cells were less abundant in SCC compared with IEC. Our study demonstrates that while IEC lesions contain a higher proportion of T-cells than SCC lesions in general, SCC lesions specifically display a lower abundance of CD8+ T-cells than IEC. We propose that differences in CD8+ T-cell abundance contribute critically to the different capacity of SCC and IEC to regress in response to immune modifying topical treatments. Our study also suggests that a high ratio of CD4+ T-cells to CD8+ T-cells may be a immunological diagnostic indicator of late-stage SCC development in immune-competent patients.
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RANK- and c-Met-mediated signal network promotes prostate cancer metastatic colonization.
Endocr. Relat. Cancer
PUBLISHED: 01-01-2014
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Prostate cancer (PCa) metastasis to bone is lethal and there is no adequate animal model for studying the mechanisms underlying the metastatic process. Here, we report that receptor activator of NF-?B ligand (RANKL) expressed by PCa cells consistently induced colonization or metastasis to bone in animal models. RANK-mediated signaling established a premetastatic niche through a feed-forward loop, involving the induction of RANKL and c-Met, but repression of androgen receptor (AR) expression and AR signaling pathways. Site-directed mutagenesis and transcription factor (TF) deletion/interference assays identified common TF complexes, c-Myc/Max, and AP4 as critical regulatory nodes. RANKL-RANK signaling activated a number of master regulator TFs that control the epithelial-to-mesenchymal transition (Twist1, Slug, Zeb1, and Zeb2), stem cell properties (Sox2, Myc, Oct3/4, and Nanog), neuroendocrine differentiation (Sox9, HIF1?, and FoxA2), and osteomimicry (c-Myc/Max, Sox2, Sox9, HIF1?, and Runx2). Abrogating RANK or its downstream c-Myc/Max or c-Met signaling network minimized or abolished skeletal metastasis in mice. RANKL-expressing LNCaP cells recruited and induced neighboring non metastatic LNCaP cells to express RANKL, c-Met/activated c-Met, while downregulating AR expression. These initially non-metastatic cells, once retrieved from the tumors, acquired the potential to colonize and grow in bone. These findings identify a novel mechanism of tumor growth in bone that involves tumor cell reprogramming via RANK-RANKL signaling, as well as a form of signal amplification that mediates recruitment and stable transformation of non-metastatic bystander dormant cells.
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Nrf1 and Nrf2 transcription factors regulate androgen receptor transactivation in prostate cancer cells.
PLoS ONE
PUBLISHED: 01-01-2014
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Despite androgen deprivation therapy (ADT), persistent androgen receptor (AR) signaling enables outgrowth of castration resistant prostate cancer (CRPC). In prostate cancer (PCa) cells, ADT may enhance AR activity through induction of oxidative stress. Herein, we investigated the roles of Nrf1 and Nrf2, transcription factors that regulate antioxidant gene expression, on hormone-mediated AR transactivation using a syngeneic in vitro model of androgen dependent (LNCaP) and castration resistant (C4-2B) PCa cells. Dihydrotestosterone (DHT) stimulated transactivation of the androgen response element (ARE) was significantly greater in C4-2B cells than in LNCaP cells. DHT-induced AR transactivation was coupled with higher nuclear translocation of p65-Nrf1 in C4-2B cells, as compared to LNCaP cells. Conversely, DHT stimulation suppressed total Nrf2 levels in C4-2B cells but elevated total Nrf2 levels in LNCaP cells. Interestingly, siRNA mediated silencing of Nrf1 attenuated AR transactivation while p65-Nrf1 overexpression enhanced AR transactivation. Subsequent studies showed that Nrf1 physically interacts with AR and enhances AR's DNA-binding activity, suggesting that the p65-Nrf1 isoform is a potential AR coactivator. In contrast, Nrf2 suppressed AR-mediated transactivation by stimulating the nuclear accumulation of the p120-Nrf1 which suppressed AR transactivation. Quantitative RT-PCR studies further validated the inductive effects of p65-Nrf1 isoform on the androgen regulated genes, PSA and TMPRSS2. Therefore, our findings implicate differential roles of Nrf1 and Nrf2 in regulating AR transactivation in PCa cells. Our findings also indicate that the DHT-stimulated increase in p65-Nrf1 and the simultaneous suppression of both Nrf2 and p120-Nrf1 ultimately facilitates AR transactivation in CRPC cells.
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The NADH Oxidase ENOX1, a Critical Mediator of Endothelial Cell Radiosensitization, Is Crucial for Vascular Development.
Cancer Res.
PUBLISHED: 11-18-2013
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ENOX1 is a highly conserved NADH oxidase that helps to regulate intracellular nicotinamide adenine dinucleotide levels in many cell types, including endothelial cells. Pharmacologic and RNA interference (RNAi)-mediated suppression of ENOX1 impairs surrogate markers of tumor angiogenesis/vasculogenesis, providing support for the concept that ENOX1 represents an antiangiogenic druggable target. However, direct genetic evidence that demonstrates a role for ENOX1 in vascular development is lacking. In this study, we exploited a zebrafish embryonic model of development to address this question. Whole-mount in situ hybridization coupled with immunofluorescence performed on zebrafish embryos demonstrate that enox1 message and translated protein are expressed in most tissues, and its expression is enriched in blood vessels and heart. Morpholino-mediated suppression of Enox1 in Tg(fli1-eGFP) and Tg(flk1-eGFP) zebrafish embryos significantly impairs the development of vasculature and blood circulation. Using in vivo multiphoton microscopy, we show that morpholino-mediated knockdown of enox1 increases NADH levels, consistent with loss of enzyme. VJ115 is a small-molecule inhibitor of Enox1s oxidase activity shown to increase intracellular NADH in endothelial cells; we used VJ115 to determine if the oxidase activity was crucial for vascular development. We found that VJ115 suppressed vasculogenesis in Tg(fli1-eGFP) embryos and impaired circulation. Previously, it was shown that suppression of ENOX1 radiosensitizes proliferating tumor vasculature, a consequence of enhanced endothelial cell apoptosis. Thus, our current findings, coupled with previous research, support the hypothesis that ENOX1 represents a potential cancer therapy target, one that combines molecular targeting with cytotoxic sensitization. Cancer Res; 74(1); 1-6. ©2013 AACR.
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Forensic epidemiology: a method for investigating and quantifying specific causation.
Forensic Sci Med Pathol
PUBLISHED: 10-28-2013
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The field of forensic epidemiology was initially introduced as a systematic approach to the investigation of acts of bioterrorism. In recent years, however, the applications of forensic epidemiology have expanded greatly, covering a wide range of medicolegal issues routinely encountered in both criminal and civil court settings. Forensic epidemiology provides a method of evaluating causation in groups and individuals based in the application of the Hill Criteria, with conclusions given in terms of relative or comparative risk, or as a Probability of Causation. The purpose of this paper is to give a brief overview of the methods and applications of forensic epidemiology.
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Cost-effectiveness of 64-slice CT angiography compared to conventional coronary angiography based on a coverage with evidence development study in Ontario.
Expert Rev Pharmacoecon Outcomes Res
PUBLISHED: 10-22-2013
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Conventional coronary angiography (CCA) is the standard diagnostic for coronary artery disease (CAD), but multi-detector computed tomography coronary angiography (CTCA) is a non-invasive alternative. Methods: A multi-center coverage with evidence development study was undertaken and combined with an economic model to estimate the cost-effectiveness of CTCA followed by CCA vs CCA alone. Alternative assumptions were tested in patient scenario and sensitivity analyses. Results: CCA was found to dominate CTCA, however, CTCA was relatively more cost-effective in females, in advancing age, in patients with lower pre-test probabilities of CAD, the higher the sensitivity of CTCA and the lower the probability of undergoing a confirmatory CCA following a positive CTCA. Conclusions: Results were very sensitive to alternative patient populations and modeling assumptions. Careful consideration of patient characteristics, procedures to improve the diagnostic yield of CTCA and selective use of CCA following CTCA will impact whether CTCA is cost-effective or dominates CCA.
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Field trial of active remote sensing using a high-power short-wave infrared supercontinuum laser.
Appl Opt
PUBLISHED: 10-03-2013
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Field trial results of a 5 W all-fiber broadband supercontinuum (SC) laser covering the short-wave infrared (SWIR) wavelength bands from ~1.55 to 2.35 ?m are presented. The SC laser is kept on a 12 story tower at the Wright Patterson Air Force Base and propagated through the atmosphere to a target 1.6 km away. Beam quality of the SC laser after propagating through 1.6 km is studied using a SWIR camera and show a near diffraction limited beam with an M(2) value of <1.3. The SC laser is used as the illumination source to perform spectral reflectance measurements of various samples at 1.6 km, and the results are seen to be in good agreement with in-lab measurements using a conventional lamp source. Spectral stability measurements are performed after atmospheric propagation through 1.6 km and show a relative variability of ~4%-8% across the spectrum depending on the atmospheric turbulence effects. Spectral stability measurements are also performed in-lab and show a relative variability of <0.6% across the spectrum.
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Large oncosomes mediate intercellular transfer of functional microRNA.
Cell Cycle
PUBLISHED: 09-23-2013
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Prostate cancer cells release atypically large extracellular vesicles (EVs), termed large oncosomes, which may play a role in the tumor microenvironment by transporting bioactive molecules across tissue spaces and through the blood stream. In this study, we applied a novel method for selective isolation of large oncosomes applicable to human platelet-poor plasma, where the presence of caveolin-1-positive large oncosomes identified patients with metastatic disease. This procedure was also used to validate results of a miRNA array performed on heterogeneous populations of EVs isolated from tumorigenic RWPE-2 prostate cells and from isogenic non-tumorigenic RWPE-1 cells. The results showed that distinct classes of miRNAs are expressed at higher levels in EVs derived from the tumorigenic cells in comparison to their non-tumorigenic counterpart. Large oncosomes enhanced migration of cancer-associated fibroblasts (CAFs), an effect that was increased by miR-1227, a miRNA abundant in large oncosomes produced by RWPE-2 cells. Our findings suggest that large oncosomes in the circulation report metastatic disease in patients with prostate cancer, and that this class of EV harbors functional molecules that may play a role in conditioning the tumor microenvironment.
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Can stroma reaction predict cancer lethality?
Clin. Cancer Res.
PUBLISHED: 09-05-2013
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Stromal features in carcinomas may provide a relatively consistent means to stratify patients afflicted with solid tumors. Stroma-derived transcriptome signatures can now be used to make predictions about patient survival, suggesting the potential for their clinical application in precision medicine to predict disease progression and emergence of therapeutic resistance.
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Colitogenic effector T cells: roles of gut-homing integrin, gut antigen specificity and ?? T cells.
Immunol. Cell Biol.
PUBLISHED: 08-21-2013
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Disturbance of T-cell homeostasis could lead to intestinal inflammation. Naive CD4 T cells undergoing spontaneous proliferation, a robust proliferative response that occurs under severe lymphopenic conditions, differentiate into effector cells producing Th1- and/or Th17-type cytokines and induce a chronic inflammation in the intestine that resembles human inflammatory bowel disease. In this study, we investigated the key properties of CD4 T cells necessary to induce experimental colitis. ?4?7 upregulation was primarily induced by mesenteric lymph node (mLN) resident CD11b(+) dendritic cell subsets via transforming growth factor beta (TGF?)/retinoic acid-dependent mechanism. Interestingly, ?4?7 expression was essential but not sufficient to induce inflammation. In addition to gut-homing specificity, expression of gut Ag specificity was also crucial. T-cell acquisition of the specificity was dramatically enhanced by the presence of ?? T cells, a population previously shown to exacerbate T-cell-mediated colitis. Importantly, interleukin (IL)-23-mediated ?? T cell stimulation was necessary to enhance colitogenicity but not gut antigen reactivity of proliferating CD4 T cells. These findings demonstrate that T-cell colitogenicity is achieved through multiple processes, offering a therapeutic rationale by intervening these pathways.Immunology and Cell Biology advance online publication, 5 November 2013; doi:10.1038/icb.2013.70.
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Power scalable >25 W supercontinuum laser from 2 to 2.5 ?m with near-diffraction-limited beam and low output variability.
Opt Lett
PUBLISHED: 07-02-2013
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A power scalable thulium-doped fiber-amplifier-based supercontinuum (SC) laser covering the shortwave infrared region from 2 to 2.5 ?m is demonstrated. The SC laser has an average power up to 25.7 W and a spectral density of >12 dBm/nm. Power scalability of the laser is proven by showing that the SC laser maintains a nearly constant spectral output, beam quality (M(2) measurements), and output spectral stability as the SC average power is scaled from 5 to 25.7 W average output power. We verify that the SC laser beam is nearly diffraction limited with an M(2)<1.2 for all power levels. Output spectral stability measurements with power scaling show a radiometric variability of <0.8% across the entire SC spectrum.
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Loss of caveolin-1 in prostate cancer stroma correlates with reduced relapse-free survival and is functionally relevant to tumour progression.
J. Pathol.
PUBLISHED: 05-24-2013
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Levels of caveolin-1 (Cav-1) in tumour epithelial cells increase during prostate cancer progression. Conversely, Cav-1 expression in the stroma can decline in advanced and metastatic prostate cancer. In a large cohort of 724 prostate cancers, we observed significantly decreased levels of stromal Cav-1 in concordance with increased Gleason score (p = 0.012). Importantly, reduced expression of Cav-1 in the stroma correlated with reduced relapse-free survival (p = 0.009), suggesting a role for stromal Cav-1 in inhibiting advanced disease. Silencing of Cav-1 by shRNA in WPMY-1 prostate fibroblasts resulted in up-regulation of Akt phosphorylation, and significantly altered expression of genes involved in angiogenesis, invasion, and metastasis, including a > 2.5-fold increase in TGF-?1 and ?-synuclein (SNCG) gene expression. Moreover, silencing of Cav-1 induced migration of prostate cancer cells when stromal cells were used as attractants. Pharmacological inhibition of Akt caused down-regulation of TGF-?1 and SNCG, suggesting that loss of Cav-1 in the stroma can influence Akt-mediated signalling in the tumour microenvironment. Cav-1-depleted stromal cells exhibited increased levels of intracellular cholesterol, a precursor for androgen biosynthesis, steroidogenic enzymes, and testosterone. These findings suggest that loss of Cav-1 in the tumour microenvironment contributes to the metastatic behaviour of tumour cells by a mechanism that involves up-regulation of TGF-?1 and SNCG through Akt activation. They also suggest that intracrine production of androgens, a process relevant to castration resistance, may occur in the stroma.
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Head and neck injury patterns in fatal falls: Epidemiologic and biomechanical considerations.
J Forensic Leg Med
PUBLISHED: 05-08-2013
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Fatal falls often involve a head impact, which are in turn associated with a fracture of the skull or cervical spine. Prior authors have noted that the degree of inversion of the victim at the time of impact is an important predictor of the distribution of skull fractures, with skull base fractures more common than skull vault fractures in falls with a high degree of inversion. The majority of fatal fall publications have focused on skull fractures, and no research has described the association between fall circumstances and the distribution of fractures in the skull and neck. In the present study, we accessed data regarding head and neck fractures resulting from fatal falls from a Swedish autopsy database for the years 1992-2010, for the purposes of examining the relationships between skull and cervical spine fracture distribution and the circumstances of the fatal fall. Out of 102,310 medico-legal autopsies performed there were 1008 cases of falls associated with skull or cervical spine fractures. The circumstances of the falls were grouped in 3 statistically homogenous categories; falls occurring at ground level, falls from a height of <3 m or down stairs, and falls from ?3 m. Only head and neck injuries and fractures that were associated with the fatal CNS injuries were included for study, and categorized as skull vault and skull base fractures, upper cervical injuries (C0-C1 dislocation, C1 and C2 fractures), and lower cervical fractures. Logistic regression modeling revealed increased odds of skull base and lower cervical fracture in the middle and upper fall severity groups, relative to ground level falls (lower cervical <3 m falls, OR = 2.55 [1.32, 4.92]; lower cervical ?3 m falls, OR = 2.23 [0.98, 5.08]; skull base <3 m falls, OR = 1.82 [1.32, 2.50]; skull base ?3 m falls, OR = 2.30 [1.55, 3.40]). C0-C1 dislocations were strongly related to fall height, with an OR of 8.3 for ?3 m falls versus ground level. The findings of increased odds of skull base and lower cervical spine fracture in falls from a height are consistent with prior observations that the risk of such injuries is related to the degree of victim inversion at impact. The finding that C0-C1 dislocations are most common in falls from more than 3 m is unique, an indication that the injuries likely result from high energy shear forces rather than pure tension, as previously thought.
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Nrf2 is essential for the expression of lipocalin-prostaglandin D synthase induced by prostaglandin D2.
Free Radic. Biol. Med.
PUBLISHED: 04-16-2013
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Nrf2 is a transcription factor that protects against inflammatory diseases, but the underlying mechanism of this effect remains unclear. Here, we report that Nrf2 uses lipocalin-prostaglandin D synthase (L-PGDS) as a mechanism for suppressing inflammation. Exogenously added prostaglandin D2 (PGD2) induced L-PGDS expression in bone-marrow-derived macrophages (BMDMs), suggesting a positive feedback loop between L-PGDS expression and PGD2. Unlike lipopolysaccharide (LPS)-induced L-PGDS expression, PGD2-mediated expression was independent of MAPK, PU.1, or TLR4. Sequence analysis located a putative Nrf2 binding site in the murine L-PGDS promoter, to which Nrf2 bound when treated with PGD2. Chemical activation, or overexpression, of Nrf2 was sufficient to induce L-PGDS expression in macrophages, BMDMs, or lungs of Nrf2-knockout (KO) mice, but treatment with PGD2 failed to do so, suggesting a pivotal role for Nrf2 in the expression of L-PGDS. Consistent with this, expression of Nrf2 in the lungs of Nrf2-KO mice was sufficient to induce the expression of L-PGDS and to reduce neutrophilic lung inflammation elicited by LPS. Furthermore, expression of L-PGDS in mouse lungs decreased neutrophilic infiltration, ameliorating lung inflammation in mice. Together, our results show that Nrf2, activated by PGD2, induced L-PGDS expression, resulting in decreased inflammation. We suggest that the positive feedback induction of L-PGDS by PGD2 is part of the mechanism by which Nrf2 regulates inflammation.
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Knockdown of aberrantly upregulated aryl hydrocarbon receptor reduces tumor growth and metastasis of MDA-MB-231 human breast cancer cell line.
Int. J. Cancer
PUBLISHED: 04-15-2013
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The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that belongs to the basic-helix-loop-helix (bHLH)-Per-ARNT-Sim (PAS) superfamily of transcription factors, mediates toxic response induced by environmental chemicals such as polycyclic aromatic hydrocarbons (PAH). AhR is expressed at high levels in several human breast carcinoma cell lines in direct correlation with the degree of their malignancy. Recent studies suggest a possible role for AhR in cancer independent of PAH. Therefore, we established stable AhR knockdown cells of the human breast cancer cell line MDA-MB-231 and analyzed their tumorigenic properties in in vitro and in vivo model systems. In addition we analyzed their response to radiation and chemotherapeutic treatment. AhR knockdown attenuated these cells tumorigenic properties in vitro including proliferation, anchorage independent growth, migration and apoptosis and reduced orthotopic xenograft tumor growth and lung metastasis in vivo. Notably, we observed that AhR knockdown enhanced radiation-induced apoptosis as well as significantly decreased cell clonogenic survival. Furthermore, AhR knockdown in MDA-MB-231 cells sensitized them to paclitaxel treatment, evident by a decrease in the required cytotoxic dose. Subsequent analysis revealed AhR knockdown significantly reduced phosphorylation of AKT, which impacts cell proliferation and survival. Apoptosis-focused gene expression analyses revealed an altered expression of genes regulating apoptosis in MDA-MB-231 cells. Collectively, our data identify AhR as a potential novel therapeutic target in the treatment of metastatic breast cancer.
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The relationship between vehicle roof crush and head, neck and spine injury in rollover crashes.
Accid Anal Prev
PUBLISHED: 04-15-2013
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It is well established that rollover crashes are associated with a higher risk of serious injury and death than other types of crashes. Some of the most serious injuries that can result from a rollover crash are those to the head, neck and spine. The mechanism of injury to these body parts in a rollover is a matter of dispute in the literature. Some authors have concluded that the magnitude of vehicle roof deformation or vertical roof crush resulting from a rollover crash is not causally associated with head and neck injury severity, while others offer support for a causal association between roof crush and the degree of injury. A better understanding of the cause of serious injuries resulting from rollover crashes is important for improving injury prevention.
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Percutaneous injection of autologous, culture-expanded mesenchymal stem cells into carpometacarpal hand joints: a case series with an untreated comparison group.
Wien Med Wochenschr
PUBLISHED: 04-01-2013
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In the present study, we describe six patients who received autologous mesenchymal stem cell (MSC) therapy for symptomatic carpometacarpal (CMC) joint and hand osteoarthritis (OA). Six patients who received injections of adult autologous culture expanded MSCs in their thumb CMC joints were followed for 1 year posttreatment, and matched with four procedure candidates who remained untreated. We observed positive outcomes in the treatment group for both symptoms and function related to the OA, compared with a reported worsening among the untreated controls. While these results should be interpreted with caution because of the small number of treated subjects and lack of placebo control and randomization, we find sufficient evidence for further investigation of MSC therapy as an alternative to more invasive surgery in patients with OA of the hand.
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Monolayer-protected nanoparticle doped xerogels as functional components of amperometric glucose biosensors.
Anal. Chem.
PUBLISHED: 03-26-2013
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First-generation amperometric glucose biosensors incorporating alkanethiolate-protected gold nanoparticles, monolayer protected clusters (MPCs), within a xerogel matrix are investigated as model systems for nanomaterial-assisted electrochemical sensing strategies. The xerogel biosensors are comprised of platinum electrodes modified with composite films of (3-mercaptopropyl)trimethoxy silane xerogel embedded with glucose oxidase enzyme, doped with Au225(C6)75 MPCs, and coated with an outer polyurethane layer. Electrochemistry and scanning/transmission electron microscopy, including cross-sectional TEM, show sensor construction, humidity effects on xerogel structure, and successful incorporation of MPCs. Analytical performance of the biosensor scheme with and without MPC doping of the xerogel is determined from direct glucose injection during amperometry. MPC-doped xerogels yield significant enhancement of several sensor attributes compared to analogous films without nanoparticles: doubling of the linear range, sensitivity enhancement by an order of magnitude, and 4-fold faster response times accompany long-term stability and resistance to common interfering agents that are competitive with current glucose biosensing literature. Ligand chain length and the MPC/silane ratio studies suggest the MPC-induced enhancements are critically related to structure-function relationships, particularly those affecting interparticle electronic communication where the MPC network behaves as a three-dimensional extension of the working electrode into the xerogel film, reducing the systems dependence on diffusion and maximizing efficiency of the sensing mechanism. The integration of MPCs as a functional component of amperometric biosensor schemes has implications for future development of biosensors targeting clinically relevant species.
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Manipulation of regulatory genes reveals complexity and fidelity in hormaomycin biosynthesis.
Chem. Biol.
PUBLISHED: 03-21-2013
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Hormaomycin (HRM) is a structurally remarkable peptide produced by Streptomyces griseoflavus W-384 that acts as a Streptomyces signaling metabolite and exhibits potent antibiotic activity against coryneform actinomycetes. HRM biosynthetic studies have been hampered by inconsistent and low production. To enhance fermentation titers, the role of its cluster-encoded regulatory genes was investigated. Extra copies of the putative regulators hrmA and hrmB were introduced into the wild-type strain, resulting in an increase of HRM production and its analogs up to 135-fold. For the HrmB overproducer, six bioactive analogs were isolated and characterized. This study demonstrates that HrmA and HrmB are positive regulators in HRM biosynthesis. A third gene, hrmH, was identified as encoding a protein capable of shifting the metabolic profile of HRM and its derivatives. Its manipulation resulted in the generation of an additional HRM analog.
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Identification and characterization of proteins isolated from microvesicles derived from human lung cancer pleural effusions.
Proteomics
PUBLISHED: 03-08-2013
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Microvesicles (MVs, also known as exosomes, ectosomes, microparticles) are released by various cancer cells, including lung, colorectal, and prostate carcinoma cells. MVs released from tumor cells and other sources accumulate in the circulation and in pleural effusion. Although recent studies have shown that MVs play multiple roles in tumor progression, the potential pathological roles of MV in pleural effusion, and their protein composition, are still unknown. In this study, we report the first global proteomic analysis of highly purified MVs derived from human nonsmall cell lung cancer (NSCLC) pleural effusion. Using nano-LC-MS/MS following 1D SDS-PAGE separation, we identified a total of 912 MV proteins with high confidence. Three independent experiments on three patients showed that MV proteins from PE were distinct from MV obtained from other malignancies. Bioinformatics analyses of the MS data identified pathologically relevant proteins and potential diagnostic makers for NSCLC, including lung-enriched surface antigens and proteins related to epidermal growth factor receptor signaling. These findings provide new insight into the diverse functions of MVs in cancer progression and will aid in the development of novel diagnostic tools for NSCLC.
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NADPH oxidase and Nrf2 regulate gastric aspiration-induced inflammation and acute lung injury.
J. Immunol.
PUBLISHED: 01-07-2013
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Recruitment of neutrophils and release of reactive oxygen species are considered to be major pathogenic components driving acute lung injury (ALI). However, NADPH oxidase, the major source of reactive oxygen species in activated phagocytes, can paradoxically limit inflammation and injury. We hypothesized that NADPH oxidase protects against ALI by limiting neutrophilic inflammation and activating Nrf2, a transcriptional factor that induces antioxidative and cytoprotective pathways. Our objective was to delineate the roles of NADPH oxidase and Nrf2 in modulating acute lung inflammation and injury in clinically relevant models of acute gastric aspiration injury, a major cause of ALI. Acid aspiration caused increased ALI (as assessed by bronchoalveolar lavage fluid albumin concentration) in both NADPH oxidase-deficient mice and Nrf2(-/-) mice compared with wild-type mice. NADPH oxidase reduced airway neutrophil accumulation, but Nrf2 decreased ALI without affecting neutrophil recovery. Acid injury resulted in a 120-fold increase in mitochondrial DNA, a proinflammatory and injurious product of cellular necrosis, in cell-free bronchoalveolar lavage fluid. Pharmacologic activation of Nrf2 by the triterpenoid 1-[2-cyano-3-,12-dioxooleana-1,9 (11)-dien-28-oyl]imidazole limited aspiration-induced ALI in wild-type mice and reduced endothelial cell injury caused by mitochondrial extract-primed human neutrophils, leading to the conclusion that NADPH oxidase and Nrf2 have coordinated, but distinct, functions in modulating inflammation and injury. These results also point to Nrf2 as a therapeutic target to limit ALI by attenuating neutrophil-induced cellular injury.
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Androgens regulate MMPs and the cellular processes of intimal hyperplasia.
J. Surg. Res.
PUBLISHED: 01-05-2013
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Testosterone deficiency has been associated with an increased risk of vascular disease. Matrix metalloproteinases (MMPs) have been implicated in vascular remodeling. Our group has demonstrated an association between female hormones and MMP-modulated intimal hyperplasia. In the present study, we investigated testosterone in the modulation of MMPs and the cellular processes of intimal hyperplasia.
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Alternative Imaging Modalities in Ischemic Heart Failure (AIMI-HF) IMAGE HF Project I-A: study protocol for a randomized controlled trial.
Trials
PUBLISHED: 01-04-2013
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Ischemic heart disease (IHD) is the most common cause of heart failure (HF); however, the role of revascularization in these patients is still unclear. Consensus on proper use of cardiac imaging to help determine which candidates should be considered for revascularization has been hindered by the absence of clinical studies that objectively and prospectively compare the prognostic information of each test obtained using both standard and advanced imaging.
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Doxorubicin-Mediated Bone Loss in Breast Cancer Bone Metastases Is Driven by an Interplay between Oxidative Stress and Induction of TGF?.
PLoS ONE
PUBLISHED: 01-01-2013
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Breast cancer patients, who are already at increased risk of developing bone metastases and osteolytic bone damage, are often treated with doxorubicin. Unfortunately, doxorubicin has been reported to induce damage to bone. Moreover, we have previously reported that doxorubicin treatment increases circulating levels of TGF? in murine pre-clinical models. TGF? has been implicated in promoting osteolytic bone damage, a consequence of increased osteoclast-mediated resorption and suppression of osteoblast differentiation. Therefore, we hypothesized that in a preclinical breast cancer bone metastasis model, administration of doxorubicin would accelerate bone loss in a TGF?-mediated manner. Administration of doxorubicin to 4T1 tumor-bearing mice produced an eightfold increase in osteolytic lesion areas compared untreated tumor-bearing mice (P?=?0.002) and an almost 50% decrease in trabecular bone volume expressed in BV/TV (P?=?0.0005), both of which were rescued by anti-TGF? antibody (1D11). Doxorubicin, which is a known inducer of oxidative stress, decreased osteoblast survival and differentiation, which was rescued by N-acetyl cysteine (NAC). Furthermore, doxorubicin treatment decreased Cu-ZnSOD (SOD1) expression and enzyme activity in vitro, and treatment with anti-TGF? antibody was able to rescue both. In conclusion, a combination therapy using doxorubicin and anti-TGF? antibody might be beneficial for preventing therapy-related bone loss in cancer patients.
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A prospective epidemiological study of acute mountain sickness in Nepalese pilgrims ascending to high altitude (4380 m).
PLoS ONE
PUBLISHED: 01-01-2013
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Each year, thousands of pilgrims travel to the Janai Purnima festival in Gosainkunda, Nepal (4380 m), ascending rapidly and often without the aid of pharmaceutical prophylaxis.
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MicroRNA-185 and 342 inhibit tumorigenicity and induce apoptosis through blockade of the SREBP metabolic pathway in prostate cancer cells.
PLoS ONE
PUBLISHED: 01-01-2013
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MicroRNA (miRNA or miR) inhibition of oncogenic related pathways has been shown to be a promising therapeutic approach for cancer. Aberrant lipid and cholesterol metabolism is involved in prostate cancer development and progression to end-stage disease. We recently demonstrated that a key transcription factor for lipogenesis, sterol regulatory element-binding protein-1 (SREBP-1), induced fatty acid and lipid accumulation and androgen receptor (AR) transcriptional activity, and also promoted prostate cancer cell growth and castration resistance. SREBP-1 was overexpressed in human prostate cancer and castration-resistant patient specimens. These experimental and clinical results indicate that SREBP-1 is a potential oncogenic transcription factor in prostate cancer. In this study, we identified two miRNAs, miR-185 and 342, that control lipogenesis and cholesterogenesis in prostate cancer cells by inhibiting SREBP-1 and 2 expression and down-regulating their targeted genes, including fatty acid synthase (FASN) and 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR). Both miR-185 and 342 inhibited tumorigenicity, cell growth, migration and invasion in prostate cancer cell culture and xenograft models coincident with their blockade of lipogenesis and cholesterogenesis. Intrinsic miR-185 and 342 expression was significantly decreased in prostate cancer cells compared to non-cancerous epithelial cells. Restoration of miR-185 and 342 led to caspase-dependent apoptotic death in prostate cancer cells. The newly identified miRNAs, miR-185 and 342, represent a novel targeting mechanism for prostate cancer therapy.
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Importance of antibody in virus infection and vaccine-mediated protection by a latency-deficient recombinant murine ?-herpesvirus-68.
J. Immunol.
PUBLISHED: 12-23-2011
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The human ?-herpesviruses EBV and Kaposis sarcoma-associated herpesvirus establish lifelong latent infections, can reactivate in immunocompromised individuals, and are associated with the development of malignancies. Murine ?-herpesvirus-68 (?HV68), a rodent pathogen related to EBV and Kaposis sarcoma-associated herpesvirus, provides an important model to dissect mechanisms of immune control and investigate vaccine strategies. Infection of mice with ?HV68 elicits robust antiviral immunity, and long-term protection from ?HV68 reactivation requires both cellular and humoral immune responses. Vaccination of mice with AC-replication and transcription activator (RTA), a highly lytic latency-null recombinant ?HV68, results in complete protection from wild-type ?HV68 infection that lasts for at least 10 mo. In this report, we examine the immune correlates of AC-RTA-mediated protection and show that sterilizing immunity requires both T cells and Ab. Importantly, Ab was also critical for mitigating viral infection in the brain, and in the absence of Ab-mediated control, amplification of the AC-RTA virus in the brain resulted in fatality. Our results highlight important considerations in the development of vaccination strategies based on live-attenuated viruses.
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A metabolic perturbation by U0126 identifies a role for glutamine in resveratrol-induced cell death.
Cancer Biol. Ther.
PUBLISHED: 12-01-2011
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Recent evidence has identified substantial overlap between metabolic and oncogenic biochemical pathways, suggesting novel approaches to cancer intervention. For example, cholesterol lowering statins and the antidiabetes medication metformin both act as chemopreventive agents in prostate and other cancers. The natural compound resveratrol has similar properties: increasing insulin sensitivity, suppressing adipogenesis, and inducing apoptotic death of cancer cells in vitro. However, in vivo tumor xenografts acquire resistance to resveratrol by an unknown mechanism, while mouse models of metabolic disorders respond more consistently to the compound. Here we demonstrate that castration-resistant human prostate cancer C4-2 cells are more sensitive to resveratrol-induced apoptosis than isogenic androgen-dependent LNCaP cells. The MEK inhibitor U0126 antagonized resveratrol-induced apoptosis in C4-2 cells, but this effect was not seen with other MEK inhibitors. U0126 was found to inhibit mitochondrial function and shift cells to aerobic glycolysis independently of MEK. Mitochondrial activity of U0126 arose through decomposition, producing both mitochondrial fluorescence and cyanide, a known inhibitor of complex IV. Applying U0126 mitochondrial inhibition to C4-2 cell apoptosis, we tested the possibility that glutamine supplementation of citric acid cycle intermediate ?-ketoglutarate may be involved. Suppression of the conversion of glutamate to ?-ketoglutarate antagonized resveratrol-induced death in C4-2 cells. A similar effect was also seen by reducing extracellular glutamine concentration in the culture medium, suggesting that resveratrol-induced death is dependent on glutamine metabolism, a process frequently dysregulated in cancer. Further work on resveratrol and metabolism in cancer is warranted to ascertain if the glutamine dependence has clinical implications.
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Antiproliferative factor signaling and interstitial cystitis/painful bladder syndrome.
Int Neurourol J
PUBLISHED: 11-30-2011
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A unique glycopeptide, antiproliferative factor (APF), has been suggested as a urinary biomarker and potential mediator of long-term bladder disorder Interstitial Cystitis/Painful Bladder Syndrome. There is no known cause for this disease. Several mechanistic approaches have been employed to address the underlying mechanism whereby APF regulates cellular responses in the bladder epithelium. A summary of recent literature is provided, and is focused on signal transduction pathways and networks that are responsive to APF.
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Cutting edge: activation of virus-specific CD4 T cells throughout ?-herpesvirus latency.
J. Immunol.
PUBLISHED: 11-11-2011
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CD4 T cells are essential for immune control of ?-herpesvirus latency. We previously identified a murine MHC class II-restricted epitope in ?-herpesvirus-68 gp150 (gp150(67-83)I-A(b)) that elicits CD4 T cells that are maintained throughout long-term infection. However, it is unknown whether naive cells can be recruited into the antiviral CD4 T cell pool during latency. In this study, we generate a mouse transgenic for a gp150-specific TCR and show epitope-specific activation of transgenic CD4 T cells during acute and latent infections. Furthermore, although only dendritic cells can stimulate virus-specific CD8 T cells during latency, we show that both dendritic cells and B cells stimulate transgenic CD4 T cells. These studies demonstrate that naive CD4 T cells specific for a viral glycoprotein can be stimulated throughout infection, even during quiescent latency, suggesting that CD4 T cell memory is maintained in part by the continual recruitment of naive cells.
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Synthesis, assembly, and characterization of monolayer protected gold nanoparticle films for protein monolayer electrochemistry.
J Vis Exp
PUBLISHED: 10-13-2011
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Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM). In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton (¹H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials.
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Is cosmetic platelet-rich plasma a drug to be regulated by the Food and Drug Administration?
J Cosmet Dermatol
PUBLISHED: 09-08-2011
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In the area of cosmetic dermatology, some physicians have been injecting activated platelet-rich plasma into the face to promote cosmesis or using it to enhance fat grafts. However, subtle changes to the federal drug code (21 CFR 1271.1) made in 2004, when applied to activated PRP, purport to make this autologous substance a federally regulated drug requiring an extensive and costly Biologics License Application. Are autologous cells drugs? Many physicians believe there are significant problems with this regulatory paradigm.
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The novel chemical entity YTR107 inhibits recruitment of nucleophosmin to sites of DNA damage, suppressing repair of DNA double-strand breaks and enhancing radiosensitization.
Clin. Cancer Res.
PUBLISHED: 08-30-2011
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Radiation therapy continues to be an important therapeutic strategy for providing definitive local/regional control of human cancer. However, oncogenes that harbor driver mutations and/or amplifications can compromise therapeutic efficacy. Thus, there is a need for novel approaches that enhance the DNA damage produced by ionizing radiation.
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De novo infection of B cells during murine gammaherpesvirus 68 latency.
J. Virol.
PUBLISHED: 08-17-2011
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The mechanisms by which gammaherpesviruses maintain latency are unclear. Here we used a murine gammaherpesvirus model to show that previously uninfected B cells in immunocompetent mice can acquire virus during latency. In vivo depletion of T cells allowed viral reactivation, as measured by increased viral loads, but not enhanced transfer of virus to new cells. In the absence of both immune T cells and antibody following the transfer of latently infected cells into naïve animals, there was robust infection of new B cells. These data confirm that both T cells and antibody contribute to the control of gammaherpesvirus latency, reactivation, and spread.
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Proteomic analysis of palmitoylated platelet proteins.
Blood
PUBLISHED: 08-02-2011
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Protein palmitoylation is a dynamic process that regulates membrane targeting of proteins and protein-protein interactions. We have previously demonstrated a critical role for protein palmitoylation in platelet activation and have identified palmitoylation machinery in platelets. Using a novel proteomic approach, Palmitoyl Protein Identification and Site Characterization, we have begun to characterize the human platelet palmitoylome. Palmitoylated proteins were enriched from membranes isolated from resting platelets using acyl-biotinyl exchange chemistry, followed by identification using liquid chromatography-tandem mass spectrometry. This global analysis identified > 1300 proteins, of which 215 met criteria for significance and represent the platelet palmitoylome. This collection includes 51 known palmitoylated proteins, 61 putative palmitoylated proteins identified in other palmitoylation-specific proteomic studies, and 103 new putative palmitoylated proteins. Of these candidates, we chose to validate the palmitoylation of triggering receptors expressed on myeloid cell (TREM)-like transcript-1 (TLT-1) as its expression is restricted to platelets and megakaryocytes. We determined that TLT-1 is a palmitoylated protein using metabolic labeling with [³H]palmitate and identified the site of TLT-1 palmitoylation as cysteine 196. The discovery of new platelet palmitoyl protein candidates will provide a resource for subsequent investigations to validate the palmitoylation of these proteins and to determine the role palmitoylation plays in their function.
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An evaluation of applied biomechanics as an adjunct to systematic specific causation in forensic medicine.
Wien Med Wochenschr
PUBLISHED: 07-29-2011
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Biomechanical tests of post hoc probability have been proposed by prior authors as reliable tests of causation in forensic settings. Biomechanical assessment of injury kinetics and kinematics is a potentially important tool in forensic medicine, but there is also the potential for misapplication. The most reliable application is when biomechanical analysis is used to explain injury mechanisms, such as how an injury may have occurred. When a biomechanical analysis is used as a means of determining whether, rather than how an injury has resulted from a traumatic exposure, then a lack of reliability of the methodology limits its application in forensic medicine. Herein, we describe a systematic assessment of causation by adapting established general causation principles to specific causation scenarios, and how biomechanical analysis of injury mechanics is properly used to augment such an approach in conjunction with the principles of forensic epidemiology. An example calculation of relative risk associated with cervical spine injury is provided as a representative probabilistic metric for assessing causation. The statistical benefits and limitations of biomechanical analysis are discussed as an adjunct to forensic medicine.
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Inflammatory chemokine receptors regulate CD8(+) T cell contraction and memory generation following infection.
J. Exp. Med.
PUBLISHED: 07-25-2011
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The development of T cell memory from naive precursors is influenced by molecular cues received during T cell activation and differentiation. In this study, we describe a novel role for the chemokine receptors CCR5 and CXCR3 in regulating effector CD8(+) T cell contraction and memory generation after influenza virus infection. We find that Ccr5(-/-) Cxcr3(-/-) cells show markedly decreased contraction after viral clearance, leading to the establishment of massive numbers of memory CD8(+) T cells. Ccr5(-/-) Cxcr3(-/-) cells show reduced expression of CD69 in the lung during the peak of infection, which coincides with differential localization and the rapid appearance of memory precursor cells. Analysis of single chemokine receptor-deficient cells revealed that CXCR3 is primarily responsible for this phenotype, although there is also a role for CCR5 in the enhancement of T cell memory. The phenotype could be reversed by adding exogenous antigen, resulting in the activation and contraction of Ccr5(-/-) Cxcr3(-/-) cells. Similar results were observed during chronic Mycobacterium tuberculosis infection. Together, the data support a model of memory CD8(+) T cell generation in which the chemokine-directed localization of T cells within infected tissues regulates antigen encounter and controls the extent of CD8(+) T cell activation and differentiation, which ultimately regulates effector versus memory cell fate decisions.
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Photothermolysis of sebaceous glands in human skin ex vivo with a 1,708?nm Raman fiber laser and contact cooling.
Lasers Surg Med
PUBLISHED: 07-16-2011
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Wavelengths near ?1,720?nm are of interest for targeting fat/lipid-rich tissues due to the high absorption coefficient of human fat and low water scattering and absorption. In this study, a 1,708?nm laser was built and shown to selectively target fat/lipid adjacent to porcine heart and dermis and then used to damage dermal sebaceous glands in human skin. STUDY DESIGN AND MATERIALS: An all-fiber 1,708?nm laser with ?4?W maximum power was designed and built. Selectivity for targeting fat/lipid was studied by exposing porcine heart and skin tissue cross-sections to the 1,708?nm laser. Human skin treatments to damage sebaceous glands were performed both with and without cold window cooling. Histochemical evaluation on the frozen sections was performed using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay.
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Does FDG PET-assisted management of patients with left ventricular dysfunction improve quality of life? A substudy of the PARR-2 trial.
Can J Cardiol
PUBLISHED: 07-12-2011
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Patients with left ventricular dysfunction whose management is directed by F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging may have a quality of life (QOL) benefit over standard care.
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The complex interplay between cholesterol and prostate malignancy.
Urol. Clin. North Am.
PUBLISHED: 06-22-2011
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Research into the role of cholesterol and prostate disease has been ongoing for many years, but our mechanistic and translational understanding is still poor. Recent evidence indicates that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer. This article reviews the literature on the relationship between circulating cholesterol and prostate cancer. The data strongly point to hypercholesterolemia as a risk factor for prostate cancer progression and suggest clinical opportunities for the use of cholesterol-lowering therapies to alter disease course.
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Definition of the common and divergent steps in carbapenem ?-lactam antibiotic biosynthesis.
Chembiochem
PUBLISHED: 06-11-2011
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Approximately 50 naturally occurring carbapenem ?-lactam antibiotics are known. All but one of these have been isolated from Streptomyces species and are disubstituted structural variants of a simple core that is synthesized by Pectobacterium carotovorum (Erwinia carotovora), a phylogenetically distant plant pathogen. While the biosynthesis of the simple carbapenem, (5R)-carbapen-2-em-3-carboxylic acid, is impressively efficient requiring only three enzymes, CarA, CarB and CarC, the formation of thienamycin, one of the former group of metabolites from Streptomyces, is markedly more complex. Despite their phylogenetic separation, bioinformatic analysis of the encoding gene clusters suggests that the two pathways could be related. Here we demonstrate with gene swapping, stereochemical and kinetics experiments that CarB and CarA and their S. cattleya orthologues, ThnE and ThnM, respectively, are functionally and stereochemically equivalent, although their catalytic efficiencies differ. The biosynthetic pathways, therefore, to thienamycin, and likely to the other disubstituted carbapenems, and to the simplest carbapenem, (5R)-carbapen-2-em-3-carboxylic acid, are initiated in the same manner, but share only two common steps before diverging.
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MST1 is a multifunctional caspase-independent inhibitor of androgenic signaling.
Cancer Res.
PUBLISHED: 04-21-2011
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The MST1 serine-threonine kinase, a component of the RASSF1-LATS tumor suppressor network, is involved in cell proliferation and apoptosis and has been implicated in cancer. However, the physiologic role of MST1 in prostate cancer (PCa) is not well understood. Here, we investigated the possibility of a biochemical and functional link between androgen receptor (AR) and MST1 signaling. We showed that MST1 forms a protein complex with AR and antagonizes AR transcriptional activity as shown by coimmunoprecipitation (co-IP), promoter reporter analysis, and molecular genetic methods. In vitro kinase and site-specific mutagenesis approaches indicate that MST1 is a potent AR kinase; however, the kinase activity of MST1 and its proapoptotic functions were shown not to be involved in inhibition of AR. MST1 was also found in AR-chromatin complexes, and enforced expression of MST1 reduced the binding of AR to a well-characterized, androgen-responsive region within the prostate-specific antigen promoter. MST1 suppressed PCa cell growth in vitro and tumor growth in mice. Because MST1 is also involved in regulating the AKT1 pathway, this kinase may be an important new link between androgenic and growth factor signaling and a novel therapeutic target in PCa.
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Loss of NRF2 impairs gastric nitrergic stimulation and function.
Free Radic. Biol. Med.
PUBLISHED: 04-17-2011
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Emerging research suggests that antioxidant gene expression has the potential to suppress the development of gastroparesis. However, direct genetic evidence that definitively supports this concept is lacking. We used mice carrying a targeted disruption of Nfe2l2, the gene that encodes the transcription factor NRF2 and directs antioxidant Phase II gene expression, as well as mice with a targeted disruption of Gclm, the modifier subunit for glutamate-cysteine ligase, to test the hypothesis that defective antioxidant gene expression contributes to development of gastroparesis. Although expression of heme oxygenase-1 remained unchanged, expression of GCLC, GCLM, SOD1, and CAT was down-regulated in gastric tissue from Nrf2(-/-) mice compared to wild-type animals. Tetrahydrobiopterin oxidation was significantly elevated and nitrergic relaxation was impaired in Nrf2(-/-) mouse gastric tissue. In vitro studies showed a significant decrease in NO release in Nrf2(-/-) mouse gastric tissue. Nrf2(-/-) mice displayed delayed gastric emptying. The use of Gclm(-/-) mice demonstrated that the loss of glutamate-cysteine ligase function enhanced tetrahydrobiopterin oxidation while impairing nitrergic relaxation. These results provide genetic evidence that loss of antioxidant gene expression can contribute to the development of gastroparesis and suggest that NRF2 represents a potential therapeutic target.
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Simplified Symptom Pattern Method for verbal autopsy analysis: multisite validation study using clinical diagnostic gold standards.
Popul Health Metr
PUBLISHED: 04-14-2011
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Verbal autopsy can be a useful tool for generating cause of death data in data-sparse regions around the world. The Symptom Pattern (SP) Method is one promising approach to analyzing verbal autopsy data, but it has not been tested rigorously with gold standard diagnostic criteria. We propose a simplified version of SP and evaluate its performance using verbal autopsy data with accompanying true cause of death.
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Performance of InterVA for assigning causes of death to verbal autopsies: multisite validation study using clinical diagnostic gold standards.
Popul Health Metr
PUBLISHED: 04-13-2011
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InterVA is a widely disseminated tool for cause of death attribution using information from verbal autopsies. Several studies have attempted to validate the concordance and accuracy of the tool, but the main limitation of these studies is that they compare cause of death as ascertained through hospital record review or hospital discharge diagnosis with the results of InterVA. This study provides a unique opportunity to assess the performance of InterVA compared to physician-certified verbal autopsies (PCVA) and alternative automated methods for analysis.
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Safety and complications reporting update on the re-implantation of culture-expanded mesenchymal stem cells using autologous platelet lysate technique.
Curr Stem Cell Res Ther
PUBLISHED: 03-27-2011
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Mesenchymal stem cells (MSCs) hold great promise as therapeutic agents in regenerative medicine. Numerous animal studies have documented the multipotency of MSCs, showing their capabilities for differentiating into orthopedic tissues such as muscle, bone, cartilage, and tendon. However, the safety of culture expanded MSCs for human use has only just begun to be reported.
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Cholesterol and benign prostate disease.
Differentiation
PUBLISHED: 03-21-2011
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The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association between BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemia, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept.
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Quantitative proteomics identifies a beta-catenin network as an element of the signaling response to Frizzled-8 protein-related antiproliferative factor.
Mol. Cell Proteomics
PUBLISHED: 03-21-2011
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Antiproliferative factor (APF), a Frizzled-8 protein-related sialoglycopeptide involved in the pathogenesis of interstitial cystitis, potently inhibits proliferation of normal urothelial cells as well as certain cancer cells. To elucidate the molecular mechanisms of the growth-inhibitory effect of APF, we performed stable isotope labeling by amino acids in cell culture analysis of T24 bladder cancer cells treated with and without APF. Among over 2000 proteins identified, 54 were significantly up-regulated and 48 were down-regulated by APF treatment. Bioinformatic analysis revealed that a protein network involved in cell adhesion was substantially altered by APF and that ?-catenin was a prominent node in this network. Functional assays demonstrated that APF down-regulated ?-catenin, at least in part, via proteasomal and lysosomal degradation. Moreover, silencing of ?-catenin mimicked the antiproliferative effect of APF whereas ectopic expression of nondegradable ?-catenin rescued growth inhibition in response to APF, confirming that ?-catenin is a key mediator of APF signaling. Notably, the key role of ?-catenin in APF signaling is not restricted to T24 cells, but was also observed in an hTERT-immortalized human bladder epithelial cell line, TRT-HU1. In addition, the network model suggested that ?-catenin is linked to cyclooxygenase-2 (COX-2), implying a potential connection between APF and inflammation. Functional assays verified that APF increased the production of prostaglandin E(2) and that down-modulation of ?-catenin elevated COX-2 expression, whereas forced expression of nondegradable ?-catenin inhibited APF-induced up-regulation of COX-2. Furthermore, we confirmed that ?-catenin was down-regulated whereas COX-2 was up-regulated in epithelial cells explanted from IC bladder biopsies compared with control tissues. In summary, our quantitative proteomics study describes the first provisional APF-regulated protein network, within which ?-catenin is a key node, and provides new insight that targeting the ?-catenin signaling pathway may be a rational approach toward treating interstitial cystitis.
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Circulating herpes simplex type 1 (HSV-1)-specific CD8+ T cells do not access HSV-1 latently infected trigeminal ganglia.
Herpesviridae
PUBLISHED: 03-15-2011
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Therapeutic vaccines can be designed to enhance existing T cell memory populations for increased protection against re-infection. In the case of herpes simplex virus type 1, recurrent disease results from reactivation of latent virus in sensory ganglia, which is controlled in part by a ganglia-resident HSV-specific memory CD8+ T cell population. Thus, an important goal of a therapeutic HSV-1 vaccine would be to enhance this population.
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Ontario multidetector computed tomographic coronary angiography study: field evaluation of diagnostic accuracy.
Arch. Intern. Med.
PUBLISHED: 03-14-2011
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Computed tomographic coronary angiography (CTCA) has gained clinical acceptance for the detection of obstructive coronary artery disease. Although single-center studies have demonstrated excellent accuracy, multicenter studies have yielded variable results. The true diagnostic accuracy of CTCA in the "real world" remains uncertain. We conducted a field evaluation comparing multidetector CTCA with invasive CA (ICA) to understand CTCAs diagnostic accuracy in a real-world setting.
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The Catalytic Diversity of Multimodular Polyketide Synthases: Natural Product Biosynthesis Beyond Textbook Assembly Rules.
Top Curr Chem
PUBLISHED: 03-02-2011
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Bacterial multimodular polyketide synthases (PKSs) are responsible for the biosynthesis of a wide range of pharmacologically active natural products. These megaenzymes contain numerous catalytic and structural domains and act as biochemical templates to generate complex polyketides in an assembly line-like fashion. While the prototypical PKS is composed of only a few different domain types that are fused together in a combinatorial fashion, an increasing number of enzymes is being found that contain additional components. These domains can introduce remarkably diverse modifications into polyketides. This review discusses our current understanding of such noncanonical domains and their role in expanding the biosynthetic versatility of bacterial PKSs.
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VentX trans-activates p53 and p16ink4a to regulate cellular senescence.
J. Biol. Chem.
PUBLISHED: 02-16-2011
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Cell senescence is a process of irreversible arrest of cell proliferation and plays an important role in tumor suppression. Recent studies showed that Wnt inhibition is a trigger of cellular senescence. Using methods of reverse genetics, we recently identified VentX, a human homolog of the vertebrate Xenopus Vent family of homeobox genes, as a novel Wnt repressor and a putative tumor suppressor in lymphocytic leukemia. Here, we show that VentX is a direct transcriptional activator of p53-p21 and p16ink4a-Rb tumor suppression pathways. Ectopic expression of VentX in cancer cells caused an irreversible cell cycle arrest with a typical senescence-like phenotype. Conversely, inhibition of VentX expression by RNA interference ameliorated chemotherapeutic agent-induced senescence in lymphocytic leukemia cells. The results of our study further reveal the mechanisms underlying tumor suppression function of VentX and suggest a role of VentX as a potential target in cancer prevention and treatment.
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NRF2 deficiency reduces life span of mice administered thoracic irradiation.
Free Radic. Biol. Med.
PUBLISHED: 02-03-2011
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Subsets of cancer survivors who have been subjected to thoracic irradiation face the prospect of developing pulmonary injury. Radiation-induced pulmonary fibrosis is an insidious injury that presents 6 to 24 months after irradiation and continues to progress over a period of years. TGF-? and reactive oxygen species contribute significantly to the pathogenesis of this injury. The transcription factor NRF2 controls antioxidant gene expression and therefore regulates the cellular oxidant burden. This work demonstrates an additional paradigm for NRF2: suppression of TGF-?-mediated signaling, assessed by measuring expression of a surrogate TGF-?1 target gene (PAI-1) in lung fibroblasts. Thoracic irradiation of Nfe2l2(-/-) mice resulted in rapid expression of PAI-1 and FSP-1 compared to irradiated wild-type mice. Examination of lung tissue 16 weeks after thoracic irradiation of Nfe2l2(-/-) mice revealed the presence of distended alveoli and decreased numbers of alveoli compared to wild-type mice. Suppression of NRF2 expression shortened life span in mice administered 16 Gy to the thorax. Nfe2l2(+/-) and Nfe2l2(-/-) mice exhibited a mean life span of 176 days compared to wild-type mice, which lived an average of 212 days. These novel results identify NRF2 as a susceptibility factor for the development of late tissue injury.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.