1,162 research outputs found

    Flame resistant nontoxic polymer development

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    A number of homopolymers, copolymers, and terpolymers were synthesized employing styrene and four derivatives of diphenyl-p-styrylphosphine. The various polymeric compositions were prepared by two processes, (1) monomer bulk polymerizations and (2) substitution of preformed polydiphenyl-p-styrylphosphine. Results indicate that the majority of the compositions exhibit superior melting and flame retardant characteristics as compared to polystyrene, but are inferior in molding and film forming capability. Terpolymerization appears to result in the materials with the best overall combination of properties. Toxicological evaluation of three representative basic compositions in the form of molded washers showed that no mortalities occurred among the test animals exposed to the products of the oxidative thermal decomposition of the three materials

    Bose-Fermi mixtures in the molecular limit

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    We consider a Bose-Fermi mixture in the molecular limit of the attractive interaction between fermions and bosons. For a boson density smaller or equal to the fermion density, we show analytically how a T-matrix approach for the constituent bosons and fermions recovers the expected physical limit of a Fermi-Fermi mixture of molecules and atoms. In this limit, we derive simple expressions for the self-energies, the momentum distribution function, and the chemical potentials. By extending these equations to a trapped system, we determine how to tailor the experimental parameters of a Bose-Fermi mixture in order to enhance the 'indirect Pauli exclusion effect' on the boson momentum distribution function. For the homogeneous system, we present finally a Diffusion Monte Carlo simulation which confirms the occurrence of such a peculiar effect.Comment: 13 pages, 7 figures; final versio

    Expression of phosphorylated eIF4E-binding protein 1, but not of eIF4E itself, predicts survival in male breast cancer

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    Background: Male breast cancer is rare and treatment is based on data from females. High expression/activity of eukaryotic initiation factor 4E (eIF4E) denotes a poor prognosis in female breast cancer, and the eIF4E pathway has been targeted therapeutically. eIF4E activity in female breast cancer is deregulated by eIF4E over-expression and by phosphorylation of its binding protein, 4E-BP1, which relieves inhibitory association between eIF4E and 4E-BP1. The relevance of the eIF4E pathway in male breast cancer is unknown. Methods: We have assessed expression levels of eIF4E, 4E-BP1, 4E-BP2 and phosphorylated 4E-BP1 (p4E-BP1) using immunohistochemistry in a large cohort of male breast cancers (n=337) and have examined correlations with prognostic factors and survival. Results: Neither eIF4E expression or estimated eIF4E activity were associated with prognosis. However, a highly significant correlation was found between p4E-BP1 expression and disease-free survival, linking any detectable p4E-BP1 with poor survival (univariate log rank p=0.001; multivariate HR 8.8, p=0.0001). Conclusions: Our data provide no support for direct therapeutic targeting of eIF4E in male breast cancer, unlike in females. However, as p4E-BP1 gives powerful prognostic insights that are unrelated to eIF4E function, p4E-BP1 may identify male breast cancers potentially suitable for therapies directed at the upstream kinase, mTOR

    Validation-based insertional mutagenesis (VBIM) technology identifies adenomatous polypossis coli (APC) like protein (ALP) as a novel negative regulator of NF-κB

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    Colorectal cancer (CRC) is the third leading cause of cancer related deaths in the United States. The nuclear factor κB (NF-κB) is an important family of transcription factors whose aberrant activation has been found in many types of cancer, including CRC. Therefore, understanding the regulation of NF-κB is of ultimate importance for cancer therapy. Using a novel validation-based insertional mutagenesis (VBIM) strategy, our lab has identified the novel adenomatous polyposis coli (APC) like protein (ALP) gene as a negative regulator of NF-κB. Preliminary studies from our lab demonstrated that overexpression of ALP led to decreased NF-κB activity by κB reporter assay and electrophoresis mobility gel shift assay (EMSA). The current project aims to further evaluate the role of ALP in the regulation of NF-κB signaling in CRC cells. We found that overexpression of ALP in human CRC HT29 cells greatly reduced both the number and the size of colonies that were formed in a soft agar assay. ALP overexpression also decreased the cell growth rate and cell migration ability, while shRNA mediated knockdown of ALP showed opposite effects, confirming that ALP is a tumor suppressor in CRC HT29 cells. Overexpression of ALP led to decreased NF-κB activity by κB reporter assay and condition media assay in CRC HT29 cells. Furthermore, immunohistochemical analysis with human colon vii tissues revealed that there is a gradual loss of ALP protein with tumor progression. We also found that ALP predominantly localizes in the cytoplasm, and binds to the p65 subunit of NF-κB, and might be functioning downstream of IκB kinase (IKK). In summary, in this study, we provide evidence regarding the tumor suppressor role of ALP in CRC by functioning as novel negative regulator of NF-κB. This discovery could lead to the establishment of ALP as a potential biomarker and therapeutic target in CRC

    Molecular phenomics and metagenomics of hepatic steatosis in non-diabetic obese women

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    The role of molecular signals from the microbiome and their coordinated interactions with those from the host in hepatic steatosis – notably in obese patients and as risk factors for insulin resistance and atherosclerosis – needs to be understood. We reveal molecular networks linking gut microbiome and host phenome to hepatic steatosis in a cohort of non diabetic obese women. Steatotic patients had low microbial gene richness and increased genetic potential for processing of dietary lipids and endotoxin biosynthesis (notably from Proteobacteria), hepatic inflammation and dysregulation of aromatic and branched-chain amino acid (AAA and BCAA) metabolism. We demonstrated that faecal microbiota transplants and chronic treatment with phenylacetic acid (PAA), a microbial product of AAA metabolism, successfully trigger steatosis and BCAA metabolism. Molecular phenomic signatures were predictive (AUC = 87%) and consistent with the gut microbiome making an impact on the steatosis phenome (>75% shared variation) and, therefore, actionable via microbiome-based therapies

    Association of Trimethylamine N-Oxide (TMAO) with the Clinical Severity of Hidradenitis Suppurativa (Acne Inversa)

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    : In this case-control, cross-sectional, observational study, we evaluated circulating trimethylamine n-oxide (TMAO) levels, a gut-derived metabolite associated with inflammation and cardiometabolic risk, in patients with hidradenitis suppurativa (HS), a highly disabling inflammatory skin disease associated with an elevated prevalence of comorbidities, especially cardiovascular and metabolic diseases. In this study, we enrolled 35 naive-treatment patients with HS and 35 controls, matched for sex, age, and body mass index (BMI). HS Sartorius score was 49.0 (33.0-75.0), while according to the Harley system 12 and 23 patients presented grade 1 and grade 2 severity, respectively. HS patients had a lower adherence to the Mediterranean diet (MD) (p = 0.002), lower phase angle (PhA) (p < 0.001), and higher circulating TMAO levels (p < 0.001) than the control group. HS patients with grade 2 rather than grade 1 of Harley grade severity showed a higher BMI (p = 0.007), waist circumference (p = 0.016), total energy intake (p = 0.005), and lower PhA (p < 0.001) and adherence to the MD (p = 0.003). Of interest, patients with Hurley grade 2 of severity exhibited higher circulating TMAO levels (p < 0.001) compared to grade 1. Circulating TMAO levels showed a positive correlation with HS Sartorius score even after adjustment for confounding covariates, including BMI, waist circumference, adherence to the MD, total energy intake, and PhA (r = 0.570, p = 0.001). Using a linear regression model, circulating TMAO levels and PhA were the main predictors of the clinical severity of HS

    The function and origin of the CD4+ T cell in the classical Hodgkin lymphoma microenvironment

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    PhDClassical Hodgkin lymphoma (CHL) is a germinal centre B cell malignancy where the bulk of the tumour comprises a non-clonal immune infiltrate enriched for CD4+ T cells. The role of these cells in the pathophysiology of CHL is poorly understood. Biomarkers predictive of clinical outcome in CHL are limited. This thesis examines microenvironment biomarkers with the goal of identifying the 10-20% of patients who are not cured by conventional therapy, and also investigates the function of the CD4+ T cell in CHL. The prognostic power of FOXP3, a marker of regulatory T cells, CD68, a macrophage marker and CD20, a B cell marker, is validated in a new patient cohort and for the first time CD68 and FOXP3 are combined in a statistically robust scoring system. The data presented challenge the assumption that the microenvironment is Th2-polarised or senescent and demonstrates relative over-expression of T-BET, a Th1 marker and under-expression of PD1, a marker of senescence/exhaustion, with little evidence for Th2 marker expression. A cytokine-enriched in vitro culture system was developed demonstrating superior proliferation and longevity of CHL-derived T cells compared to non-malignant tissue-derived controls. These cells sustain expression of markers associated with proliferation and longevity (e.g. CD27, CD28) and remain functional (express cytokines) for many weeks. A panel of CD4+ T cell-specific markers was determined capable of differentiating CHL-derived from non-malignant or non-Hodgkin lymphoma-derived CD4+ T cells, in which markers of central memory (CD62L and CCR7) and early activation (CD69) are over-represented and markers of senescence (CD57 and PD1) are under-represented. Cytokine profiles were found to resemble Th1 (expression of IL2, IFN- and TNF expression) rather than Th2 (IL4, IL13, IL21, IL10 and IL6) responses. The data presented confirm a new prognostic biomarker signature and show a Th1 rather than Th2-dominated microenvironment enriched for cytokine-secreting functional effector CD4+ T cells and long-lived, proliferative cells resembling central memory cells rather than hypoproliferative, anergic, non-functional T cells
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