17 research outputs found

    Evaluation of corrosion protection of epoxy coatings on copper during exposure to an aerated 3% NaCl solution.

    Get PDF
    In this study the anticorrosion performance of a clear epoxy coating was enhanced by the incorporation of modified zinc into the polymer matrix. The structural macroscopy by X-ray diffraction (XRD). Corrosion performance of the coated copper specimens was investigated employing polarization measurements and electrochemical impedance spectroscopy (EIS) in 3% NaCl solution. Incorporation of 5 wt% zinc possessed the best corrosion performance. The electrochemical results are completely in agreement with the morphological results of the surface obtained from scanning electron microscopy (SEM). For the theoretical study, complete geometry optimization of 4, 4′- Ethylene bis (N, N diglycidylaniline) was performed using the Density Functional Theory (DFT). The Gaussian 03W software package was used in the calculations

    A novel copper complex induces ROS generation in doxorubicin resistant Ehrlich ascitis carcinoma cells and increases activity of antioxidant enzymes in vital organs in vivo

    Get PDF
    BACKGROUND: In search of a suitable GSH-depleting agent, a novel copper complex viz., copper N-(2-hydroxyacetophenone) glycinate (CuNG) has been synthesized, which was initially found to be a potential resistance modifying agent and later found to be an immunomodulator in mice model in different doses. The objective of the present work was to decipher the effect of CuNG on reactive oxygen species (ROS) generation and antioxidant enzymes in normal and doxorubicin-resistant Ehrlich ascites carcinoma (EAC/Dox)-bearing Swiss albino mice. METHODS: The effect of CuNG has been studied on ROS generation, multidrug resistance-associated protein1 (MRP1) expression and on activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). RESULTS: CuNG increased ROS generation and reduced MRP1 expression in EAC/Dox cells while only temporarily depleted glutathione (GSH) within 2 h in heart, kidney, liver and lung of EAC/Dox bearing mice, which were restored within 24 h. The level of liver Cu was observed to be inversely proportional to the level of GSH. Moreover, CuNG modulated SOD, CAT and GPx in different organs and thereby reduced oxidative stress. Thus nontoxic dose of CuNG may be utilized to reduce MRP1 expression and thus sensitize EAC/Dox cells to standard chemotherapy. Moreover, CuNG modulated SOD, CAT and and GPx activities to reduce oxidative stress in some vital organs of EAC/Dox bearing mice. CuNG treatment also helped to recover liver and renal function in EAC/Dox bearing mice. CONCLUSION: Based on our studies, we conclude that CuNG may be a promising candidate to sensitize drug resistant cancers in the clinic

    Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

    Get PDF
    Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

    Mutant-IDH1-dependent chromatin state reprogramming, reversibility, and persistence

    Get PDF
    Mutations in IDH1 and IDH2 (encoding isocitrate dehydrogenase 1 and 2) drive the development of gliomas and other human malignancies. Mutant IDH1 induces epigenetic changes that promote tumorigenesis, but the scale and reversibility of these changes are unknown. Here, using human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant-IDH1-induced epigenomic reprogramming. We characterize the reversibility of the alterations in DNA methylation, the histone landscape, and transcriptional reprogramming that occur following IDH1 mutation. We discover genome-wide coordinate changes in the localization and intensity of multiple histone marks and chromatin states. Mutant IDH1 establishes a CD24+ population with a proliferative advantage and stem-like transcriptional features. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented high-resolution molecular portraits of mutant-IDH1-dependent epigenomic reprogramming. These findings have substantial implications for understanding of mutant IDH function and for optimizing therapeutic approaches to targeting IDH-mutant tumors

    Ultrafiltration of wastewater-models loaded with vat dyes (indigo blue) by membranes composed of organic polymers at different percentages: comparative study

    No full text
    The development of membranes intended for the ultrafiltration of wastewater-models loaded with vat dyes, the case of indigo, has taken during this work a major interest. This development was based on the synthesis of films, by phase inversion, permselective based on organic polymers such as polysulfone (PSU), polyvinyl chloride (PVC) and expanded polystyrene (PSE) on the one hand and based on octaglycidylether tetraaniline resin for methylenedianiline (OGTAPMDA), bisphenol A (BA) and titanium dioxide TiO2, on the other hand. During the first step, we synthesized five types of membranes named M1, M2, M3, M4 and M5 according to different percentages of the composition of the collodium (polymer/solvent/non-solvent) obtained namely; M1 (12 % PSU/88 % DMF), M2 (9 % PSU/ 1% PVC/ 90% DMF), M3 (13.5 % PSU/0.5 % BA/1 % PSe/85 % DMF), M4 (8.5 % PSU/1.5 % OGTAPMDA/90 % DMF) and M5 (9.5 % PSU/0.5 % TiO2/90 % DMF). The resulting membranes have already been characterized by researchers from the ECOP team, using microscopic tools such as FTIR and SEM, and macroscopic tools, based on hydrodynamic conditions, namely permeability and selectivity. The results obtained during this study show that the membranes obtained having excellent mechanical and static properties, on the one hand, and the ultrafiltration of the rejection-model, on the other hand, gave significant percentages on the rate scale. Fading and which are obtained as follows; 80.36 % for the M1 membrane, 89 % for the M2 membrane, 87.24 % for the M3 membrane, 64.79 % for the M4 membrane and 86 % for the M5 membrane
    corecore