Syndecan-1 Depletion Has a Differential Impact on Hyaluronic Acid Metabolism and Tumor Cell Behavior in Luminal and Triple-Negative Breast Cancer Cells

Glycosaminoglycans (GAGs) and proteoglycans (PGs) are major components of the glycocalyx. The secreted GAG and CD44 ligand hyaluronic acid (HA), and the cell surface PG syndecan-1 (Sdc-1) modulate the expression and activity of cytokines, chemokines, growth factors, and adhesion molecules, acting as critical regulators of tumor cell behavior. Here, we studied the effect of Sdc-1 siRNA depletion and HA treatment on hallmark processes of cancer in breast cancer cell lines of different levels of aggressiveness. We analyzed HA synthesis, and parameters relevant to tumor progression, including the stem cell phenotype, Wnt signaling constituents, cell cycle progression and apoptosis, and angiogenic markers in luminal MCF-7 and triple-negative MDA-MB-231 cells. Sdc-1 knockdown enhanced HAS-2 synthesis and HA binding in MCF-7, but not in MDA-MB-231 cells. Sdc-1-depleted MDA-MB-231 cells showed a reduced CD24-/CD44+ population. Furthermore, Sdc-1 depletion was associated with survival signals in both cell lines, affecting cell cycle progression and apoptosis evasion. These changes were linked to the altered expression of KLF4, MSI2, and miR-10b and differential changes in Erk, Akt, and PTEN signaling. We conclude that Sdc-1 knockdown differentially affects HA metabolism in luminal and triple-negative breast cancer model cell lines and impacts the stem phenotype, cell survival, and angiogenic factors.     

Impact of cycling temperatures on Fusarium verticillioides and Fusarium graminearum growth and mycotoxins production in soybean

BACKGROUND: Fusarium graminearum and F. verticillioides are two very important mycotoxigenic species as they cause diverse diseases in crops. The effects of constant and cycling temperatures on growth and mycotoxin production of these species were studied on soybean based medium and on irradiated soya beans. RESULTS: F. graminearum grew better when was incubated at 15, 20 and 15–20 °C (isothermal or cycling temperature) during 21 days of incubation. Maximum levels of zearalenone and deoxynivalenol (39.25 and 1040.4 µg g^?1, respectively) were detected on soya beans after 15 days of incubation and the optimal temperature for mycotoxin production was 15 °C for zearalenone and 20 °C for deoxynivalenol. F. verticillioides grew better at 25 °C in culture medium and at 15/20 °C and 15/25 °C on soybean seeds. Fumonisin B₁ was produced only in culture medium, and the maximum level (7.38 µg g^?1) was found at 15 °C after 7 days of incubation. CONCLUSION: When growth and mycotoxin production under cycling temperatures were predicted from the results under constant conditions, observed values were different from calculated for both species and substrate medium. Therefore, care should be taken if data at constant temperature conditions are to be extrapolated to real field conditions. Copyright © 2012 Society of Chemical Industry     

Effect of APE1 T2197G (Asp148Glu) Polymorphism on APE1, XRCC1, PARP1 and OGG1 Expression in Patients with Colorectal Cancer

It has been hypothesized that genetic variation in base excision repair (BER) might modify colorectal adenoma risk. Thus, we evaluated the influence of APE1 T2197G (Asp148Glu) polymorphism on APE1, XRCC1, PARP1 and OGG1 expression in normal and tumor samples from patients with colorectal cancer. The results indicate a downregulation of OGG1 and an upregulation of XRCC1 expression in tumor tissue. Regarding the anatomical location of APE1, OGG1 and PARP-1, a decrease in gene expression was observed among patients with cancer in the rectum. In patients with or without some degree of tumor invasion, a significant downregulation in OGG1 was observed in tumor tissue. Interestingly, when taking into account the tumor stage, patients with more advanced grades (III and IV) showed a significant repression for APE1, OGG1 and PARP-1. XRCC1 expression levels were significantly enhanced in tumor samples and were correlated with all clinical and histopathological data. Concerning the polymorphism T2197G, GG genotype carriers exhibited a significantly reduced expression of genes of the BER repair system (APE1, XRCC1 and PARP1). In summary, our data show that patients with colorectal cancer present expression changes in several BER genes, suggesting a role for APE1, XRCC1, PARP1 and OGG1 and APE1 polymorphism in colorectal carcinogenesis.     

Experiments with micro-fin tube in single phase

This work shows heat transfer and friction characteristics for water single-phase flow in micro-fin tubes. The analysis of thermal and hydraulic behavior from a laminar to a turbulent flow was carried out in an experimental setup with a 9.52 mm diameter micro-fin tube. The tube was wrapped up with an electrical resistance tape to supply a constant heat flux to its surface. Different operational conditions were considered in the heating tests. The inlet and outlet temperatures, differential wall temperatures along the tube, pressure drop and flow rate were measured. The relationships of heat flux and flow rate with heat transfer coefficient and pressure drop were analyzed. Under the same conditions, comparative experiments with an internally smooth tube were conducted. The micro-fin tube provides higher heat transfer performance than the smooth tube (in turbulent flow h_micro-fin/h_smooth=2.9). In spite of the increase in pressure drop (Δp_micro-fin/Δp_smooth=1.7) the heat transfer results were significantly higher (about 80%). This shows the advantages of this enhanced configuration in thermal performance related to conventional tubes. The smooth tube results were validated by the comparison with the Dittus–Boelter and Gnielinski correlations. For the micro-fin tube an empirical correlation to the heat transfer coefficient adjusted from the set of measured data is proposed. The values obtained are in conformity with experimental results.     

Ascorbic acid reduces the endotoxin-induced lung injury in awake sheep

Our aim was to investigate whether ascorbic acid can reduce reactive oxygen metabolite-mediated acute lung injury. The effects of intravenous administration of Escherichia coli endotoxin were studied, with and without ascorbic acid infusion, on haemodynamics, lung lymph flow, cardio-respiratory and neutrophil function in chronically instrumented sheep. Paired experiments were performed on eight sheep in which they received either endotoxin alone (0.5 micrograms kg-1 b.w.) (ET group) or in combination with an ascorbic acid infusion (1 g kg-1 b.w. bolus injection followed by 0.2 g kg-1 h-1 continuous infusion) ET + ASC group) in random order. Four of the animals also received ascorbic acid alone (ASC group). As a result, for the ET + ASC group a general and mostly significant improvement (P < 0.05) in the early hypertensive phase (0-60 min, P values) and in the late permeability phase (2-4 h, *P values) of cardiorespiratory function (mean artery pressure: P/*P = 0.283/0.049; mean pulmonary artery pressure: P/*P = 0.0001/0.0001; mean pulmonary artery wedge pressure: P/*P = 0.012/0.001; right ventricular stroke work index: P/*P = 0.02/0.0001; cardiac index: P/*P = 0.797/0.755; arterial oxygen saturation: P/*P = 0.0059/0.01; arterial-venous difference of oxygen tension: P/*P = 0.011/0.0005), oxygen consumption: P/*P = 0.013/0.035, lung lymph flow: P/*P = 0.562/0.012, lymph/plasma protein ratio: P/*P = 0.304/0.008 and protein clearance: P/*P = 0.56/0.05 was observed in comparison with the ET group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct stent implantation without predilatation using the MultiLink stent

The standard coronary stent implantation technique requires routine predilatation of the target lesion with a balloon catheter. In this study, we prospectively studied the feasibility and efficiency of elective coronary stent implantation without predilatation. In 94 patients who presented with various ischemic syndromes, direct implantation of 100 balloon expandable ACS MultiLink stents (7 over-the-wire, 93 rapid exchange) was attempted in 100 coronary lesions selected to have favorable characteristics. The stent crossed the lesion without predilatation in 97 cases (97%) and was successfully deployed in 93 (95.8%). In 4 patients, adjunctive high-pressure postdilatation was necessary to achieve optimal stent expansion. Reference vessel diameter was 3.12+/-0.77 mm and lesion length 8.8+/-2.7 mm. Minimal luminal diameter increased from 0.95+/-0.38 mm to 2.98+/-0.28 mm and diameter stenosis decreased from 71+/-11% to 8+/-11% after stenting. One occlusive dissection was treated by a second stent. There were no major in-hospital complications. At 1 month follow-up, 1 subacute thrombotic occlusion occurred. These results indicate that in a carefully selected coronary lesion subset, elective stent implantation without predilatation can be safely and effectively performed. The long-term results of this approach and possible advantages over the conventional implantation techniques remain unclear and need to be evaluated in further clinical studies.