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Sample records for membrane type-1 matrix

  1. Identification of membrane-type 1 matrix metalloproteinase tyrosine phosphorylation in association with neuroblastoma progression

    International Nuclear Information System (INIS)

    Nyalendo, Carine; Sartelet, Hervé; Barrette, Stéphane; Ohta, Shigeru; Gingras, Denis; Béliveau, Richard

    2009-01-01

    Neuroblastoma is a pediatric tumor of neural crest cells that is clinically characterized by its variable evolution, from spontaneous regression to malignancy. Despite many advances in neuroblastoma research, 60% of neuroblastoma, which are essentially metastatic cases, are associated with poor clinical outcome due to the lack of effectiveness of current therapeutic strategies. Membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14), an enzyme involved in several steps in tumor progression, has previously been shown to be associated with poor clinical outcome for neuroblastoma. Based on our recent demonstration that MT1-MMP phosphorylation is involved in the growth of fibrosarcoma tumors, we examined the potential role of phosphorylated MT1-MMP in neuroblastoma progression. Tyrosine phosphorylated MT1-MMP was immunostained on tissue microarray samples from 55 patients with neuroblastoma detected by mass screening (known to be predominantly associated with favourable outcome), and from 234 patients with standard diagnosed neuroblastoma. In addition, the effects of a non phosphorylable version of MT1-MMP on neuroblastoma cell migration and proliferation were investigated within three-dimensional collagen matrices. Although there is no correlation between the extent of tyrosine phosphorylation of MT1-MMP (pMT1-MMP) and MYCN amplification or clinical stage, we observed greater phosphorylation of pMT1-MMP in standard neuroblastoma, while it is less evident in neuroblastoma from mass screening samples (P = 0.0006) or in neuroblastoma samples from patients younger than one year (P = 0.0002). In vitro experiments showed that overexpression of a non-phosphorylable version of MT1-MMP reduced MT1-MMP-mediated neuroblastoma cell migration and proliferation within a three-dimensional type I collagen matrix, suggesting a role for the phosphorylated enzyme in the invasive properties of neuroblastoma cells. Overall, these results suggest that tyrosine phosphorylated MT1-MMP

  2. The dimer interface of the membrane type 1 matrix metalloproteinase hemopexin domain: crystal structure and biological functions.

    Science.gov (United States)

    Tochowicz, Anna; Goettig, Peter; Evans, Richard; Visse, Robert; Shitomi, Yasuyuki; Palmisano, Ralf; Ito, Noriko; Richter, Klaus; Maskos, Klaus; Franke, Daniel; Svergun, Dmitri; Nagase, Hideaki; Bode, Wolfram; Itoh, Yoshifumi

    2011-03-04

    Homodimerization is an essential step for membrane type 1 matrix metalloproteinase (MT1-MMP) to activate proMMP-2 and to degrade collagen on the cell surface. To uncover the molecular basis of the hemopexin (Hpx) domain-driven dimerization of MT1-MMP, a crystal structure of the Hpx domain was solved at 1.7 Å resolution. Two interactions were identified as potential biological dimer interfaces in the crystal structure, and mutagenesis studies revealed that the biological dimer possesses a symmetrical interaction where blades II and III of molecule A interact with blades III and II of molecule B. The mutations of amino acids involved in the interaction weakened the dimer interaction of Hpx domains in solution, and incorporation of these mutations into the full-length enzyme significantly inhibited dimer-dependent functions on the cell surface, including proMMP-2 activation, collagen degradation, and invasion into the three-dimensional collagen matrix, whereas dimer-independent functions, including gelatin film degradation and two-dimensional cell migration, were not affected. These results shed light on the structural basis of MT1-MMP dimerization that is crucial to promote cellular invasion.

  3. Matrix metalloproteinase 2 and membrane type 1 matrix metalloproteinase co-regulate axonal outgrowth of mouse retinal ganglion cells

    DEFF Research Database (Denmark)

    Gaublomme, Djoere; Buyens, Tom; De Groef, Lies

    2014-01-01

    regenerative therapies, an improved understanding of axonal outgrowth and the various molecules influencing it, is highly needed. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Using an ex vivo retinal explant model......, but not MMP-9, are involved in this process. Furthermore, administration of a novel antibody to MT1-MMP that selectively blocks pro-MMP-2 activation revealed a functional co-involvement of these proteinases in determining RGC axon outgrowth. Subsequent immunostainings showed expression of both MMP-2 and MT1...... nervous system is lacking in adult mammals, thereby impeding recovery from injury to the nervous system. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Inhibition of specific MMPs reduced neurite outgrowth from...

  4. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    Directory of Open Access Journals (Sweden)

    Anna Janowska-Wieczorek

    2012-07-01

    Full Text Available Membrane type-1 matrix metalloproteinase (MT1-MMP has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML cells. Because tumor necrosis factor (TNF-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML.

  5. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    International Nuclear Information System (INIS)

    Marquez-Curtis, Leah A.; Shirvaikar, Neeta; Turner, A. Robert; Mirza, Imran; Surmawala, Amir; Larratt, Loree M.; Janowska-Wieczorek, Anna

    2012-01-01

    Membrane type-1 matrix metalloproteinase (MT1-MMP) has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML) cells. Because tumor necrosis factor (TNF)-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i) MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii) activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii) inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML

  6. Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Curtis, Leah A.; Shirvaikar, Neeta [Canadian Blood Services R& D, Edmonton, Alberta T6G 2R8 (Canada); Turner, A. Robert [Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada); Mirza, Imran [Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2B7 (Canada); Surmawala, Amir; Larratt, Loree M. [Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada); Janowska-Wieczorek, Anna, E-mail: anna.janowska@blood.ca [Canadian Blood Services R& D, Edmonton, Alberta T6G 2R8 (Canada); Departments of Medicine and Oncology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada)

    2012-07-25

    Membrane type-1 matrix metalloproteinase (MT1-MMP) has been implicated in tumor invasion, as well as trafficking of normal hematopoietic cells, and acts as a physiologic activator of proMMP-2. In this study we examined MT1-MMP expression in primary acute myeloid leukemia (AML) cells. Because tumor necrosis factor (TNF)-α is known to be elevated in AML, we also investigated the effect of TNF-α on MT1-MMP expression. We found (i) MT1-MMP mRNA expression in 41 out of 43 primary AML samples tested; (ii) activation of proMMP-2 in co-cultures of AML cells with normal bone marrow stromal cells; and (iii) inhibition of proMMP-2 activation and trans-Matrigel migration of AML cells by gene silencing using MT1-MMP siRNA. Moreover, recombinant human TNF-α upregulated MT1-MMP expression in AML cells resulting in enhanced proMMP-2 activation and trans-Matrigel migration. Thus, AML cells express MT1-MMP and TNF-α enhances it leading to increased MMP-2 activation and most likely contributing to the invasive phenotype. We suggest that MT1-MMP, together with TNF-α, should be investigated as potential therapeutic targets in AML.

  7. In vivo imaging of membrane type-1 matrix metalloproteinase with a novel activatable near-infrared fluorescence probe.

    Science.gov (United States)

    Shimizu, Yoichi; Temma, Takashi; Hara, Isao; Makino, Akira; Kondo, Naoya; Ozeki, Ei-Ichi; Ono, Masahiro; Saji, Hideo

    2014-08-01

    Membrane type-1 matrix metalloproteinase (MT1-MMP) is a protease activating MMP-2 that mediates cleavage of extracellular matrix components and plays pivotal roles in tumor migration, invasion and metastasis. Because in vivo noninvasive imaging of MT1-MMP would be useful for tumor diagnosis, we developed a novel near-infrared (NIR) fluorescence probe that can be activated following interaction with MT1-MMP in vivo. MT1-hIC7L is an activatable fluorescence probe comprised of anti-MT1-MMP monoclonal antibodies conjugated to self-assembling polymer micelles that encapsulate NIR dyes (IC7-1, λem : 858 nm) at concentrations sufficient to cause fluorescence self-quenching. In aqueous buffer, MT1-hIC7L fluorescence was suppressed to background levels and increased approximately 35.5-fold in the presence of detergent. Cellular uptake experiments revealed that in MT1-MMP positive C6 glioma cells, MT1-hIC7L showed significantly higher fluorescence that increased with time as compared to hIC7L, a negative control probe lacking the anti-MT1-MMP monoclonal antibody. In MT1-MMP negative MCF-7 breast adenocarcinoma cells, both MT1-hIC7L and hIC7L showed no obvious fluorescence. In addition, the fluorescence intensity of C6 cells treated with MT1-hIC7L was suppressed by pre-treatment with an MT1-MMP endocytosis inhibitor (P imaging using probes intravenously administered to tumor-bearing mice showed that MT1-hIC7L specifically visualized C6 tumors (tumor-to-background ratios: 3.8 ± 0.3 [MT1-hIC7L] vs 3.1 ± 0.2 [hIC7L] 48 h after administration, P fluorescence in MCF-7 tumors. Together, these results show that MT1-hIC7L would be a potential activatable NIR probe for specifically detecting MT1-MMP-expressing tumors. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  8. Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

    Energy Technology Data Exchange (ETDEWEB)

    Kuge, Yuji [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Zhao, Yan [Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kiyono, Yasushi [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); University of Fukui, Biomedical Imaging Research Center, Fukui (Japan); Shiomi, Masashi [Kobe University Graduate School of Medicine, Institute for Experimental Animals, Kobe (Japan)

    2010-11-15

    Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of {sup 99m}Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG{sub 3} and negative control IgG{sub 3} were radiolabelled with {sup 99m}Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield {sup 99m}Tc-MT1-MMP mAb and {sup 99m}Tc-IgG{sub 3}, respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. {sup 99m}Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional {sup 99m}Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p < 0.0001), while {sup 99m}Tc-IgG{sub 3} accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest {sup 99m}Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 {+-} 1.9, %ID x BW/mm{sup 2} x 10{sup 2}), followed in decreasing order by fibroatheromatous (1.8 {+-} 1.3), collagen-rich (1.6 {+-} 1.0) and neointimal lesions (1.5 {+-} 1.5). In contrast, {sup 99m}Tc-IgG{sub 3} accumulation was almost independent of the histological grade of lesions. Higher {sup 99m}Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with {sup 99m}Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

  9. Radioimmunodetection of membrane type-1 matrix metalloproteinase relevant to tumor malignancy with a pre-targeting method

    International Nuclear Information System (INIS)

    Sano, Kohei; Temma, Takashi; Kuge, Yuji; Kudo, Takashi; Kamihashi, Junko; Saji, Hideo; Zhao, Songji

    2010-01-01

    Since membrane type-1 matrix metalloproteinase (MT1-MMP) is exclusively expressed in tumors and is closely associated with metastasis and invasion, MT1-MMP is a potential target of radiotracers for the evaluation of tumor malignancy. In this study, we planned to visualize MT1-MMP in vivo by a two-step pre-targeting strategy using a streptavidin (SAv)-biotin system combined with anti-MT1-MMP monoclonal immunoglobulin (IgG) (anti-MT1-MMP monoclonal antibody (mAb)). Streptavidinylated anti-MT1-MMP mAb was synthesized by reacting biotinylated anti-MT1-MMP mAb with SAv. In the pre-targeting study, FM3A mouse breast carcinoma-implanted mice were injected with anti-MT1-MMP mAb-SAv, followed 72 h later with radioiodinated biotin, (3-[ 123/125 I]iodobenzoyl)norbiotinamide( 123/125 I-IBB). Biodistribution and imaging (single photon emission computed tomography (SPECT)/CT) data were collected at several time points in the 24 h period following introduction of the tracer. The comparison groups were injected with 125 I-IBB alone or with 125 I-IBB pre-targeted with negative control IgG-SAv. In the pre-targeting study for MT1-MMP, within 1 h of tracer injection, rapid tumor uptake and abrupt clearance from the blood of radioactivity (2.22, 0.87% injected dose/g at 1 h) were observed. The tumor to blood (T/B) radioactivity ratios were significantly higher than those from mice dosed with the pre-targeting negative control (p 125 I-IBB alone did not accumulate in tumors. SPECT/CT image analysis of FM3A bearing mice showed high-contrast tumor images after 3 h with minimal blood-pool activity. The present study that uses a pre-targeting method showed high T/B radioactivity ratios and clear tumor images of MT1-MMP. This imaging method may be useful for the clinical diagnosis of malignant tumors. (author)

  10. Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

    International Nuclear Information System (INIS)

    Kuge, Yuji; Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo; Zhao, Yan; Kiyono, Yasushi; Shiomi, Masashi

    2010-01-01

    Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of 99m Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG 3 and negative control IgG 3 were radiolabelled with 99m Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield 99m Tc-MT1-MMP mAb and 99m Tc-IgG 3 , respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. 99m Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional 99m Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p 99m Tc-IgG 3 accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest 99m Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 ± 1.9, %ID x BW/mm 2 x 10 2 ), followed in decreasing order by fibroatheromatous (1.8 ± 1.3), collagen-rich (1.6 ± 1.0) and neointimal lesions (1.5 ± 1.5). In contrast, 99m Tc-IgG 3 accumulation was almost independent of the histological grade of lesions. Higher 99m Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with 99m Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

  11. Crystallographic characterization of the radixin FERM domain bound to the cytoplasmic tail of membrane-type 1 matrix metalloproteinase (MT1-MMP)

    International Nuclear Information System (INIS)

    Terawaki, Shin-ichi; Kitano, Ken; Aoyama, Miki; Hakoshima, Toshio

    2008-01-01

    The radixin FERM domain was shown to bind the MT1-MMP cytoplasmic peptide and crystals of the complex were obtained. ERM proteins play a role in the cross-linking found between plasma membranes and actin filaments. The N-terminal FERM domains of ERM proteins are responsible for membrane association through direct interaction with the cytoplasmic tails of integral membrane proteins. During cell migration and movement, membrane-type 1 matrix metalloproteinase (MT1-MMP) on plasma membranes sheds adhesion molecule CD44 in addition to degrading the extracellular matrix. Here, the interaction between the radixin FERM domain and the MT1-MMP cytoplasmic tail is reported and preliminary crystallographic characterization of crystals of the radixin FERM domain bound to the cytoplasmic tail of MT1-MMP is presented. The crystals belong to space group P6 1 22, with unit-cell parameters a = b = 122.7, c = 128.3 Å, and contain one complex in the crystallographic asymmetric unit. The diffraction data were collected to a resolution of 2.4 Å

  12. Membrane-Type 1 Matrix Metal loproteinase Is Regulated by Sp1 through the Differential Activation of AKT, JNK, and ERK Pathways in Human Prostate Tumor Cells

    Directory of Open Access Journals (Sweden)

    Isis C. Sroka

    2007-05-01

    Full Text Available We and other investigators have previously shown that membrane-type 1 matrix metalloproteinase (MT1-MMP is overexpressed in invasive prostate cancer cells. However, the mechanism for this expression is not known. Here, we show that MT1-MMP is minimally expressed in nonmalignant primary prostate cells, moderately expressed in DU-145 cells, and highly expressed in invasive PC-3 and PC-3N cells. Using human MT1-MMP promoter reporter plasmids and mobility shift assays, we show that Spi regulates MT1-MMP expression in DU-145, PC-3, and PC-3N cells and in PC3-N cells using chromatin immunoprecipitation analysis and silencing RNA. Investigation of signaling pathway showed that DU-145 cells express constitutively phosphorylated extracellular stress-regulated kinase (ERK, whereas PC-3 and PC-3N cells express constitutively phosphorylated AKT/PKB and c-Jun NH2 terminal kinase (JNK. We show that MT1-MMP and Spi levels are decreased in PC-3 and PC-3N cells when phosphatidylinositol-3 kinase and JNK are inhibited, and that MT1-MMP levels are decreased in DU-145 cells when MEK is inhibited. Transient transfection of PC-3 and PC-3N cells with a dominant-negative JNK or p85, and of DU-145 cells with a dominant negative ERK, reduces MT1-MMP promoter activity. These results indicate differential signaling control of Spi-mediated transcriptional regulation of MT1-MMP in prostate cancer cell lines.

  13. Retroviral gene transfer of an antisense construct against membrane type 1 matrix metalloproteinase reduces the invasiveness of rheumatoid arthritis synovial fibroblasts.

    Science.gov (United States)

    Rutkauskaite, Edita; Volkmer, Dagmar; Shigeyama, Yukio; Schedel, Jörg; Pap, Geza; Müller-Ladner, Ulf; Meinecke, Ingmar; Alexander, Dorothea; Gay, Renate E; Drynda, Susanne; Neumann, Wolfram; Michel, Beat A; Aicher, Wilhelm K; Gay, Steffen; Pap, Thomas

    2005-07-01

    Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed prominently in rheumatoid arthritis synovial fibroblasts (RASFs), but the specific contribution of MT1-MMP to fibroblast-mediated destruction of articular cartilage is incompletely understood. This study used gene transfer of an antisense expression construct to assess the effects of MT1-MMP inhibition on the invasiveness of RASFs. Retroviral gene transfer of a pLXIN vector-based antisense RNA expression construct (MT1-MMPalphaS) to MT1-MMP was used to stably transduce RASFs. Levels of MT1-MMP RNA and protein were determined by quantitative polymerase chain reaction, Western blotting, and immunocytochemistry in MT1-MMPalphaS-transduced RASFs as well as in control cells, with monitoring for 60 days. The effects of MT1-MMPalphaS on the invasiveness of RASFs were analyzed in the SCID mouse co-implantation model of RA. MT1-MMPalphaS-transduced RASFs produced high levels of antisense RNA that exceeded endogenous levels of MT1-MMP messenger RNA by 15-fold and resulted in a down-regulation of MT1-MMP at the protein level. Inhibition of MT1-MMP production was maintained for 60 days and significantly reduced the invasiveness of RASFs in the SCID mouse model. Whereas prominent invasion into cartilage by non-transduced and mock-transduced RASFs was observed (mean invasion scores 3.0 and 3.1, respectively), MT1-MMPalphaS-transduced cells showed only moderate invasiveness (mean invasion score 1.8; P < 0.05). The data demonstrate that an antisense RNA expression construct against MT1-MMP can be generated and expressed in RASFs for at least 60 days. Inhibition of MT1-MMP significantly reduces the cartilage degradation by RASFs.

  14. Membrane Type 1Matrix Metalloproteinase/Akt Signaling Axis Modulates TNF-α-Induced Procoagulant Activity and Apoptosis in Endothelial Cells

    Science.gov (United States)

    Ohkawara, Hiroshi; Ishibashi, Toshiyuki; Sugimoto, Koichi; Ikeda, Kazuhiko; Ogawa, Kazuei; Takeishi, Yasuchika

    2014-01-01

    Membrane type 1matrix metalloproteinase (MT1-MMP) functions as a signaling molecule in addition to a proteolytic enzyme. Our hypothesis was that MT1-MMP cooperates with protein kinase B (Akt) in tumor necrosis factor (TNF)-α-induced signaling pathways of vascular responses, including tissue factor (TF) procoagulant activity and endothelial apoptosis, in cultured human aortic endothelial cells (ECs). TNF-α (10 ng/mL) induced a decrease in Akt phosphorylation within 60 minutes in ECs. A chemical inhibitor of MMP, TIMP-2 and selective small interfering RNA (siRNA)-mediated suppression of MT1-MMP reversed TNF-α-triggered transient decrease of Akt phosphorylation within 60 minutes, suggesting that MT1-MMP may be a key regulator of Akt phosphorylation in TNF-α-stimulated ECs. In the downstream events, TNF-α increased TF antigen and activity, and suppressed the expression of thrombomodulin (TM) antigen. Inhibition of Akt markedly enhanced TNF-α-induced expression of TF antigen and activity, and further reduced the expression of TM antigen. Silencing of MT1-MMP by siRNA also reversed the changed expression of TF and TM induced by TNF-α. Moreover, TNF-α induced apoptosis of ECs through Akt- and forkhead box protein O1 (FoxO1)-dependent signaling pathway and nuclear factor-kB (NF-kB) activation. Knockdown of MT1-MMP by siRNA reversed apoptosis of ECs by inhibiting TNF-α-induced Akt-dependent regulation of FoxO1 in TNF-α-stimulated ECs. Immunoprecipitation demonstrated that TNF-α induced the changes in the associations between the cytoplasmic fraction of MT1-MMP and Akt in ECs. In conclusion, we show new evidence that MT1-MMP/Akt signaling axis is a key modifier for TNF-α-induced signaling pathways for modulation of procoagulant activity and apoptosis of ECs. PMID:25162582

  15. Conversion of Stationary to Invasive Tumor Initiating Cells (TICs): Role of Hypoxia in Membrane Type 1-Matrix Metalloproteinase (MT1-MMP) Trafficking

    Science.gov (United States)

    Li, Jian; Zucker, Stanley; Pulkoski-Gross, Ashleigh; Kuscu, Cem; Karaayvaz, Mihriban; Ju, Jingfang; Yao, Herui; Song, Erwei; Cao, Jian

    2012-01-01

    Emerging evidence has implicated the role of tumor initiating cells (TICs) in the process of cancer metastasis. The mechanism underlying the conversion of TICs from stationary to invasive remains to be characterized. In this report, we employed less invasive breast cancer TICs, SK-3rd, that displays CD44high/CD24low with high mammosphere-forming and tumorigenic capacities, to investigate the mechanism by which stationary TICs are converted to invasive TICs. Invasive ability of SK-3rd TICs was markedly enhanced when the cells were cultured under hypoxic conditions. Given the role of membrane type 1-matrix metalloproteinase (MT1-MMP) in cancer invasion/metastasis, we explored a possible involvement of MT1-MMP in hypoxia-induced TIC invasion. Silencing of MT1-MMP by a shRNA approach resulted in diminution of hypoxia-induced cell invasion in vitro and metastasis in vivo. Under hypoxic conditions, MT1-MMP redistributed from cytoplasmic storage pools to the cell surface of TICs, which coincides with the increased cell invasion. In addition, CD44, a cancer stem-like cell marker, inversely correlated with increased cell surface MT1-MMP. Interestingly, cell surface MT1-MMP gradually disappeared when the hypoxia-treated cells were switched to normoxia, suggesting the plasticity of TICs in response to oxygen content. Furthermore, we dissected the pathways leading to upregulated MT1-MMP in cytoplasmic storage pools under normoxic conditions, by demonstrating a cascade involving Twist1-miR10b-HoxD10 leading to enhanced MT1-MMP expression in SK-3rd TICs. These observations suggest that MT1-MMP is a key molecule capable of executing conversion of stationary TICs to invasive TICs under hypoxic conditions and thereby controlling metastasis. PMID:22679501

  16. Membrane type 1-matrix metalloproteinase/Akt signaling axis modulates TNF-α-induced procoagulant activity and apoptosis in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Hiroshi Ohkawara

    Full Text Available Membrane type 1-matrix metalloproteinase (MT1-MMP functions as a signaling molecule in addition to a proteolytic enzyme. Our hypothesis was that MT1-MMP cooperates with protein kinase B (Akt in tumor necrosis factor (TNF-α-induced signaling pathways of vascular responses, including tissue factor (TF procoagulant activity and endothelial apoptosis, in cultured human aortic endothelial cells (ECs. TNF-α (10 ng/mL induced a decrease in Akt phosphorylation within 60 minutes in ECs. A chemical inhibitor of MMP, TIMP-2 and selective small interfering RNA (siRNA-mediated suppression of MT1-MMP reversed TNF-α-triggered transient decrease of Akt phosphorylation within 60 minutes, suggesting that MT1-MMP may be a key regulator of Akt phosphorylation in TNF-α-stimulated ECs. In the downstream events, TNF-α increased TF antigen and activity, and suppressed the expression of thrombomodulin (TM antigen. Inhibition of Akt markedly enhanced TNF-α-induced expression of TF antigen and activity, and further reduced the expression of TM antigen. Silencing of MT1-MMP by siRNA also reversed the changed expression of TF and TM induced by TNF-α. Moreover, TNF-α induced apoptosis of ECs through Akt- and forkhead box protein O1 (FoxO1-dependent signaling pathway and nuclear factor-kB (NF-kB activation. Knockdown of MT1-MMP by siRNA reversed apoptosis of ECs by inhibiting TNF-α-induced Akt-dependent regulation of FoxO1 in TNF-α-stimulated ECs. Immunoprecipitation demonstrated that TNF-α induced the changes in the associations between the cytoplasmic fraction of MT1-MMP and Akt in ECs. In conclusion, we show new evidence that MT1-MMP/Akt signaling axis is a key modifier for TNF-α-induced signaling pathways for modulation of procoagulant activity and apoptosis of ECs.

  17. Characterization of retrokeratoprosthetic membranes in the Boston type 1 keratoprosthesis.

    Science.gov (United States)

    Stacy, Rebecca C; Jakobiec, Frederick A; Michaud, Norman A; Dohlman, Claes H; Colby, Kathryn A

    2011-03-01

    To evaluate retroprosthetic membranes that can occur in 25% to 65% of patients with the Boston type 1 keratoprosthesis (KPro). Two patients with Peter anomaly and 2 with neurotrophic scarred corneas underwent revisions of their type 1 KPros because of visually compromising retroprosthetic membranes. The excised membranes were studied by light microscopy with hematoxylin-eosin, periodic acid-Schiff, and toluidine blue stains. Immunohistochemical and transmission electron microscopic examination were also used. Light microscopic examination revealed that the retro-KPro fibrous membranes originated from the host's corneal stroma. These mildly to moderately vascularized membranes grew through gaps in the Descemet membrane to reach behind the KPro back plate and adhere to the anterior iris surface, which had undergone partial lysis. In 2 cases, the fibrous membranes merged at the pupil with matrical portions of metaplastic lens epithelium, forming a bilayered structure that crossed the optical axis. Retro-KPro membranes stained positively for α-smooth muscle actin but negatively for pancytokeratin. Electron microscopy confirmed the presence of actin filaments within myofibroblasts and small surviving clusters of metaplastic lens epithelial cells. Stromal downgrowth, rather than epithelial downgrowth, was the major element of the retro-KPro membranes in this series. Metaplastic lens epithelium also contributed to opacification of the visual axis. Florid membranous inflammation was not a prominent finding and thus probably not a requisite stimulus for membrane development. Further advances in prosthetic design and newer antifibroproliferative agents may reduce membrane formation.

  18. Receptor for advanced glycation end products - membrane type1 matrix metalloproteinase axis regulates tissue factor expression via RhoA and Rac1 activation in high-mobility group box-1 stimulated endothelial cells.

    Directory of Open Access Journals (Sweden)

    Koichi Sugimoto

    Full Text Available BACKGROUND: Atherosclerosis is understood to be a blood vessel inflammation. High-mobility group box-1 (HMGB-1 plays a key role in the systemic inflammation. Tissue factor (TF is known to lead to inflammation which promotes thrombus formation. Membrane type1 matrix metalloprotease (MT1-MMP associates with advanced glycation endproducts (AGE triggered-TF protein expression and phosphorylation of NF-κB. However, it is still unclear about the correlation of MT1-MMP and HMBG-1-mediated TF expression. In this study, we investigated the molecular mechanisms of TF expression in response to HMGB-1 stimulation and the involvement of MT1-MMP in endothelial cells. METHODS AND RESULTS: Pull-down assays and Western blotting revealed that HMGB-1 induced RhoA/Rac1 activation and NF-kB phosphorylation in cultured human aortic endothelial cells. HMGB-1 increased the activity of MT1-MMP, and inhibition of RAGE or MT1-MMP by siRNA suppressed HMGB-1-induced TF upregulation as well as HMGB-1-triggered RhoA/Rac1 activation and NF-kB phosphorylation. CONCLUSIONS: The present study showed that RAGE/MT1-MMP axis modified HMBG-1-mediated TF expression through RhoA and Rac1 activation and NF-κB phosphorylation in endothelial cells. These results suggested that MT1-MMP was involved in vascular inflammation and might be a good target for treating atherosclerosis.

  19. Downregulation of reversion-inducing cysteine-rich protein with Kazal motifs in malignant melanoma: inverse correlation with membrane-type 1-matrix metalloproteinase and tissue inhibitor of metalloproteinase 2.

    Science.gov (United States)

    Jacomasso, Thiago; Trombetta-Lima, Marina; Sogayar, Mari C; Winnischofer, Sheila M B

    2014-02-01

    The invasive phenotype of many tumors is associated with an imbalance between the matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), and the membrane-anchored reversion-inducing cysteine-rich protein with Kazal motifs (RECK). RECK inhibits MMP-2, MMP-9, and MT1-MMP, and has been linked to patient survival and better prognosis in several types of tumors. However, despite the wide implication of these MMPs in melanoma establishment and progression, the role of RECK in this type of tumor is still unknown. Here, we analyzed the expression of RECK, TIMP1, TIMP2, TIMP3, MT1MMP, MMP2, and MMP9 in two publicly available melanoma microarray datasets and in a panel of human melanoma cell lines. We found that RECK is downregulated in malignant melanoma, accompanied by upregulation of MT1MMP and TIMP2. In both datasets, we observed that the group of samples displaying higher RECK levels show lower median expression levels of MT1MMP and TIMP2 and higher levels of TIMP3. When tested in a sample-wise manner, these correlations were statistically significant. Inverse correlations between RECK, MT1MMP, and TIMP2 were verified in a panel of human melanoma cell lines and in a further reduced model that includes a pair of matched primary tumor-derived and metastasis-derived cell lines. Taken together, our data indicate a consistent correlation between RECK, MT1MMP, and TIMP2 across different models of clinical samples and cell lines and suggest evidence of the potential use of this subset of genes as a gene signature for diagnosing melanoma.

  20. The Peri-islet Basement Membrane, a Barrier to Infiltrating Leukocytes in Type 1 Diabetes in Mouse and Human

    DEFF Research Database (Denmark)

    Korpos, Eva; Kadri, Nadir; Kappelhoff, Reinhild

    2013-01-01

    We provide the first comprehensive analysis of the extracellular matrix (ECM) composition of peri-islet capsules, composed of the peri-islet basement membrane (BM) and subjacent interstitial matrix (IM), in development of type 1 diabetes in NOD mice and in human type 1 diabetes. Our data demonstr...... IM are reconstituted once inflammation subsides, indicating that the peri-islet BM-producing cells are not lost due to the inflammation, which has important ramifications to islet transplantation studies.......We provide the first comprehensive analysis of the extracellular matrix (ECM) composition of peri-islet capsules, composed of the peri-islet basement membrane (BM) and subjacent interstitial matrix (IM), in development of type 1 diabetes in NOD mice and in human type 1 diabetes. Our data...... demonstrate global loss of peri-islet BM and IM components only at sites of leukocyte infiltration into the islet. Stereological analyses reveal a correlation between incidence of insulitis and the number of islets showing loss of peri-islet BM versus islets with intact BMs, suggesting that leukocyte...

  1. Matrix Metalloproteinase Activity in Infections by an Encephalitic Virus, Mouse Adenovirus Type 1

    Science.gov (United States)

    Ashley, Shanna L.; Pretto, Carla D.; Stier, Matthew T.; Kadiyala, Padma; Castro-Jorge, Luiza; Hsu, Tien-Huei; Doherty, Robert; Carnahan, Kelly E.; Castro, Maria G.; Lowenstein, Pedro R.

    2017-01-01

    ABSTRACT Mouse adenovirus type 1 (MAV-1) infection causes encephalitis in susceptible strains of mice and alters the permeability of infected brains to small molecules, which indicates disruption of the blood-brain barrier (BBB). Under pathological conditions, matrix metalloproteinases (MMPs) can disrupt the BBB through their proteolytic activity on basement membrane and tight junction proteins. We examined whether MAV-1 infection alters MMP activity in vivo and in vitro. Infected MAV-1-susceptible SJL mice had higher MMP2 and MMP9 activity in brains, measured by gelatin zymography, than mock-infected mice. Infected MAV-1-resistant BALB/c mice had MMP activity levels equivalent to those in mock infection. Primary SJL mouse brain endothelial cells (a target of MAV-1 in vivo) infected ex vivo with MAV-1 had no difference in activities of secreted MMP2 and MMP9 from mock cells. We show for the first time that astrocytes and microglia are also infected in vivo by MAV-1. Infected mixed primary cultures of astrocytes and microglia had higher levels of MMP2 and MMP9 activity than mock-infected cells. These results indicate that increased MMP activity in the brains of MAV-1-infected susceptible mice may be due to MMP activity produced by endothelial cells, astrocytes, and microglia, which in turn may contribute to BBB disruption and encephalitis in susceptible mice. IMPORTANCE RNA and DNA viruses can cause encephalitis; in some cases, this is accompanied by MMP-mediated disruption of the BBB. Activated MMPs degrade extracellular matrix and cleave tight-junction proteins and cytokines, modulating their functions. MAV-1 infection of susceptible mice is a tractable small-animal model for encephalitis, and the virus causes disruption of the BBB. We showed that MAV-1 infection increases enzymatic activity of two key MMPs known to be secreted and activated in neuroinflammation, MMP2 and MMP9, in brains of susceptible mice. MAV-1 infects endothelial cells, astrocytes, and

  2. Epiretinal membrane: a treatable cause of visual disability in myotonic dystrophy type 1.

    Science.gov (United States)

    Kersten, Hannah M; Roxburgh, Richard H; Child, Nicholas; Polkinghorne, Philip J; Frampton, Chris; Danesh-Meyer, Helen V

    2014-01-01

    A wide range of ocular abnormalities have been documented to occur in patients with myotonic dystrophy type 1. The objectives of this study were to investigate the macular and optic nerve morphology using optical coherence tomography in patients with myotonic dystrophy type 1. A total of 30 myotonic dystrophy type 1 patients and 28 controls were recruited for participation. All participants underwent a thorough ophthalmologic examination, including spectral-domain optical coherence tomography of the macula and retinal nerve fibre layer. Images were reviewed by a retinal specialist ophthalmologist, masked to the diagnosis of the participants. Average macular thickness was significantly greater in the myotonic dystrophy group compared to controls [327.3 μm vs. 308.5 μm (p Visual acuity was reduced due to the presence of epiretinal membrane in six patient eyes and none of the control eyes. The presence of an epiretinal membrane was significantly correlated with increasing age in the patient group. We report an increased prevalence of epiretinal membrane in the myotonic dystrophy type 1 group. This may be a previously under-recognised form of visual impairment in this group. Epiretinal membranes can be treated surgically. We suggest that, in addition to a comprehensive clinical examination, optical coherence tomography examination is implemented as part of an ophthalmological assessment for the myotonic dystrophy type 1 patient with reduced visual acuity.

  3. Three-dimensional structure of the human immunodeficiency virus type 1 matrix protein.

    Science.gov (United States)

    Massiah, M A; Starich, M R; Paschall, C; Summers, M F; Christensen, A M; Sundquist, W I

    1994-11-25

    The HIV-1 matrix protein forms an icosahedral shell associated with the inner membrane of the mature virus. Genetic analyses have indicated that the protein performs important functions throughout the viral life-cycle, including anchoring the transmembrane envelope protein on the surface of the virus, assisting in viral penetration, transporting the proviral integration complex across the nuclear envelope, and localizing the assembling virion to the cell membrane. We now report the three-dimensional structure of recombinant HIV-1 matrix protein, determined at high resolution by nuclear magnetic resonance (NMR) methods. The HIV-1 matrix protein is the first retroviral matrix protein to be characterized structurally and only the fourth HIV-1 protein of known structure. NMR signal assignments required recently developed triple-resonance (1H, 13C, 15N) NMR methodologies because signals for 91% of 132 assigned H alpha protons and 74% of the 129 assignable backbone amide protons resonate within chemical shift ranges of 0.8 p.p.m. and 1 p.p.m., respectively. A total of 636 nuclear Overhauser effect-derived distance restraints were employed for distance geometry-based structure calculations, affording an average of 13.0 NMR-derived distance restraints per residue for the experimentally constrained amino acids. An ensemble of 25 refined distance geometry structures with penalties (sum of the squares of the distance violations) of 0.32 A2 or less and individual distance violations under 0.06 A was generated; best-fit superposition of ordered backbone heavy atoms relative to mean atom positions afforded root-mean-square deviations of 0.50 (+/- 0.08) A. The folded HIV-1 matrix protein structure is composed of five alpha-helices, a short 3(10) helical stretch, and a three-strand mixed beta-sheet. Helices I to III and the 3(10) helix pack about a central helix (IV) to form a compact globular domain that is capped by the beta-sheet. The C-terminal helix (helix V) projects away

  4. The pancreatic zymogen granule membrane protein, GP2, binds Escherichia coli type 1 Fimbriae

    Directory of Open Access Journals (Sweden)

    Lowe Anson W

    2009-07-01

    Full Text Available Abstract Background GP2 is the major membrane protein present in the pancreatic zymogen granule, and is cleaved and released into the pancreatic duct along with exocrine secretions. The function of GP2 is unknown. GP2's amino acid sequence is most similar to that of uromodulin, which is secreted by the kidney. Recent studies have demonstrated uromodulin binding to bacterial Type 1 fimbria. The fimbriae serve as adhesins to host receptors. The present study examines whether GP2 also shares similar binding properties to bacteria with Type 1 fimbria. Commensal and pathogenic bacteria, including E. coli and Salmonella, express type 1 fimbria. Methods An in vitro binding assay was used to assay the binding of recombinant GP2 to defined strains of E. coli that differ in their expression of Type 1 fimbria or its subunit protein, FimH. Studies were also performed to determine whether GP2 binding is dependent on the presence of mannose residues, which is a known determinant for FimH binding. Results GP2 binds E. coli that express Type 1 fimbria. Binding is dependent on GP2 glycosylation, and specifically the presence of mannose residues. Conclusion GP2 binds to Type 1 fimbria, a bacterial adhesin that is commonly expressed by members of the Enterobacteriacae family.

  5. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.

    Science.gov (United States)

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M P; Albano, E; Bianchi, F B

    2000-04-01

    Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.

  6. Interaction of glutaric aciduria type 1-related glutaryl-CoA dehydrogenase with mitochondrial matrix proteins.

    Directory of Open Access Journals (Sweden)

    Jessica Schmiesing

    Full Text Available Glutaric aciduria type 1 (GA1 is an inherited neurometabolic disorder caused by mutations in the GCDH gene encoding glutaryl-CoA dehydrogenase (GCDH, which forms homo- and heteromeric complexes in the mitochondrial matrix. GA1 patients are prone to the development of encephalopathic crises which lead to an irreversible disabling dystonic movement disorder. The clinical and biochemical manifestations of GA1 vary considerably and lack correlations to the genotype. Using an affinity chromatography approach we report here for the first time on the identification of mitochondrial proteins interacting directly with GCDH. Among others, dihydrolipoamide S-succinyltransferase (DLST involved in the formation of glutaryl-CoA, and the β-subunit of the electron transfer flavoprotein (ETFB serving as electron acceptor, were identified as GCDH binding partners. We have adapted the yellow fluorescent protein-based fragment complementation assay and visualized the oligomerization of GCDH as well as its direct interaction with DLST and ETFB in mitochondria of living cells. These data suggest that GCDH is a constituent of multimeric mitochondrial dehydrogenase complexes, and the characterization of their interrelated functions may provide new insights into the regulation of lysine oxidation and the pathophysiology of GA1.

  7. Influence of membrane fluidity on human immunodeficiency virus type 1 entry

    International Nuclear Information System (INIS)

    Harada, Shinji; Yusa, Keisuke; Monde, Kazuaki; Akaike, Takaaki; Maeda, Yosuke

    2005-01-01

    For penetration of human immunodeficiency virus type 1 (HIV-1), formation of fusion-pores might be required for accumulating critical numbers of fusion-activated gp41, followed by multiple-site binding of gp120 with receptors, with the help of fluidization of the plasma membrane and viral envelope. Correlation between HIV-1 infectivity and fluidity was observed by treatment of fluidity-modulators, indicating that infectivity was dependent on fluidity. A 5% decrease in fluidity suppressed the HIV-1 infectivity by 56%. Contrarily, a 5% increase in fluidity augmented the infectivity by 2.4-fold. An increased temperature of 40 deg C or treatment of 0.2% xylocaine after viral adsorption at room temperature enhanced the infectivity by 2.6- and 1.5-fold, respectively. These were inhibited by anti-CXCR4 peptide, implying that multiple-site binding was accelerated at 40 deg C or by xylocaine. Thus, fluidity of both the plasma membrane and viral envelope was required to form the fusion-pore and to complete the entry of HIV-1

  8. Associations between advanced glycation endproducts and matrix metalloproteinases and its inhibitor in individuals with type 1 diabetes

    DEFF Research Database (Denmark)

    Peeters, S A; Engelen, L; Buijs, J

    2018-01-01

    the production of MMPs and/or TIMP-1. Therefore, we investigated associations between specific AGEs and MMP-1, -2, -3, -9, and -10, and TIMP-1 in individuals with type 1 diabetes. METHODS: In 670 type 1 diabetic individuals we determined serum levels of protein-bound AGEs Nε-(carboxymethyl)lysine (CML), Nε-(carboxyethyl)lysine......AIMS: Advanced glycation endproducts (AGEs) and altered extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) are associated with vascular complications in type 1 diabetes. Experimental studies have shown that AGEs regulate...... (CEL), 5-hydro-5-methylimidazolone (MG-H1) and pentosidine, and MMP-1, -2, -3, -9, and -10, and TIMP-1. We performed linear regression analyses to investigate associations between AGEs and markers of the MMP-TIMP system. Analyses were adjusted for age, sex, HbA1c and duration of diabetes...

  9. Genetic Variation in the Matrix Metalloproteinase Genes and Diabetic Nephropathy in Type 1 Diabetes

    OpenAIRE

    Kure, Masahiko; Pezzolesi, Marcus G.; Poznik, G. David; Katavetin, Pisut; Skupien, Jan; Dunn, Jonathon S.; Mychaleckyj, Josyf C.; Warram, James H.; Krolewski, Andrzej S.

    2011-01-01

    Genetic data support the notion that polymorphisms in members of the matrix metalloproteinase (MMP) family of genes play an important role in extracellular matrix remodeling and contribute to the pathogenesis of vascular disease. To identify novel genetic markers for diabetic nephropathy (DN), we examined the relationship between MMP gene polymorphisms and DN in the Genetics of Kidneys in Diabetes (GoKinD) population. Genotypic data from the Genetic Association Information Network (GAIN) type...

  10. [Effect of extracted ZG from gardenia on Hep-2 cell membrane post infected with parainfluenza virus type 1 (PIV-1)].

    Science.gov (United States)

    Guo, Shan-Shan; Huang, Yang; Zhao, Ye; Gao, Ying-Jie; Gong, Wen-Feng; Cui, Xiao-Lan

    2007-09-01

    In order to study the anti-viral mechanism of extracted ZG from Gardenia, the effect of extracted ZG on Hep-2 cell membrane potential, Na -K+-ATPase activity and membrane fluidity post infected with parainfluenza virus type 1 (PIV-1) was observed. Acetylcholine which was fluorescent labeled with DiBAC4 (3) was taken as positive control to observe the changes of membrane potential and was measured by flow cytometer. The phosphorus determination method and spectrophotometer were used to measure the Na+-K+-ATPase activity of Hep-2 cell membrane post PIV-1 infection. Hep-2 cell membrane phospholipids was labeled with fluorescent NBD-C6-HPC and membrane fluidity was measured by confocal laser scanning microscope. The results demonstated that after PIV-1 infection the Hep-2 cell membrane potential decreased significantly and the membrane was in the state of hyperpolarization, Na+-K+-ATPase activity increased and membrane fluidity decreased significantly. There was no apparent interferring effect of extracted ZG on the changes of membrane potential and Na+-K+-ATPase activity post PIV-1 infection, while membrane fluidity was improved significantly. Acetylcholine improved the state of hyperpolarization. The changes of membrane potential, Na -K+-ATPase activity and membrane fluidity might be the biomechanism of PIV-1 infectoin. The extracted ZG improved membrane fluidity to prevent from PIV-1 infection by protecting the cell membrane, which was probably the mechanism of anti-PIV-1 activity of the extracted ZG, but ZG probably had nothing to do with membrane potential and Na+-K+-ATPase activity.

  11. Membrane and inclusion body targeting of lyssavirus matrix proteins.

    Science.gov (United States)

    Pollin, Reiko; Granzow, Harald; Köllner, Bernd; Conzelmann, Karl-Klaus; Finke, Stefan

    2013-02-01

    Lyssavirus matrix proteins (M) support virus budding and have accessory functions that may contribute to host cell manipulation and adaptation to specific hosts. Here, we show that rabies virus (RABV) and European Bat Lyssavirus Type 1 (EBLV-1) M proteins differ in targeting and accumulation at cellular membranes. In contrast to RABV M, EBLV-1 M expressed from authentic EBLV-1 or chimeric RABV accumulated at the Golgi apparatus. Chimeric M proteins revealed that Golgi association depends on the integrity of the entire EBLV-1 M protein. Since RABV and EBLV-1 M differ in the use of cellular membranes for particle formation, differential membrane targeting and transport of M might determine the site of virus production. Moreover, both RABV and EBLV-1 M were for the first time detected within the nucleus and in Negri body-like inclusions bodies. Whereas nuclear M may imply hitherto unknown functions of lyssavirus M in host cell manipulation, the presence of M in inclusion bodies may correlate with regulatory functions of M in virus RNA synthesis. The data strongly support a model in which targeting of lyssavirus M proteins to distinctintracellular sites is a key determinant of diverse features in lyssavirus replication, host adaptation and pathogenesis. © 2012 Blackwell Publishing Ltd.

  12. Influence of hyperbaric oxygen on biomechanics and structural bone matrix in type 1 diabetes mellitus rats.

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Justino Oliveira Limirio

    Full Text Available The aim of this study was to evaluate the biomechanics and structural bone matrix in diabetic rats subjected to hyperbaric oxygen therapy (HBO.Twenty-four male rats were divided into the following groups: Control; Control + HBO; Diabetic, and Diabetic + HBO. Diabetes was induced with streptozotocin (STZ in the diabetic Groups. After 30 days, HBO was performed every 48h in HBO groups and all animals were euthanized 60 days after diabetic induction. The femur was submitted to a biomechanical (maximum strength, energy-to-failure and stiffness and Attenuated Total Reflectance Fourier transform infrared (ATR-FTIR analyses (crosslink ratio, crystallinity index, matrix-to-mineral ratio: Amide I + II/Hydroxyapatite (M:MI and Amide III + Collagen/HA (M:MIII.In biomechanical analysis, diabetic animals showed lower values of maximum strength, energy and stiffness than non-diabetic animals. However, structural strength and stiffness were increased in groups with HBO compared with non-HBO. ATR-FTIR analysis showed decreased collagen maturity in the ratio of crosslink peaks in diabetic compared with the other groups. The bone from the diabetic groups showed decreased crystallinity compared with non-diabetic groups. M:MI showed no statistical difference between groups. However, M:MIII showed an increased matrix mineral ratio in diabetic+HBO and control+HBO compared with control and diabetic groups. Correlations between mechanical and ATR-FTIR analyses showed significant positive correlation between collagen maturity and stiffness.Diabetes decreased collagen maturation and the mineral deposition process, thus reducing biomechanical properties. Moreover, the study showed that HBO improved crosslink maturation and increased maximum strength and stiffness in the femur of T1DM animals.

  13. Influence of hyperbaric oxygen on biomechanics and structural bone matrix in type 1 diabetes mellitus rats.

    Science.gov (United States)

    Limirio, Pedro Henrique Justino Oliveira; da Rocha Junior, Huberth Alexandre; Morais, Richarlisson Borges de; Hiraki, Karen Renata Nakamura; Balbi, Ana Paula Coelho; Soares, Priscilla Barbosa Ferreira; Dechichi, Paula

    2018-01-01

    The aim of this study was to evaluate the biomechanics and structural bone matrix in diabetic rats subjected to hyperbaric oxygen therapy (HBO). Twenty-four male rats were divided into the following groups: Control; Control + HBO; Diabetic, and Diabetic + HBO. Diabetes was induced with streptozotocin (STZ) in the diabetic Groups. After 30 days, HBO was performed every 48h in HBO groups and all animals were euthanized 60 days after diabetic induction. The femur was submitted to a biomechanical (maximum strength, energy-to-failure and stiffness) and Attenuated Total Reflectance Fourier transform infrared (ATR-FTIR) analyses (crosslink ratio, crystallinity index, matrix-to-mineral ratio: Amide I + II/Hydroxyapatite (M:MI) and Amide III + Collagen/HA (M:MIII)). In biomechanical analysis, diabetic animals showed lower values of maximum strength, energy and stiffness than non-diabetic animals. However, structural strength and stiffness were increased in groups with HBO compared with non-HBO. ATR-FTIR analysis showed decreased collagen maturity in the ratio of crosslink peaks in diabetic compared with the other groups. The bone from the diabetic groups showed decreased crystallinity compared with non-diabetic groups. M:MI showed no statistical difference between groups. However, M:MIII showed an increased matrix mineral ratio in diabetic+HBO and control+HBO compared with control and diabetic groups. Correlations between mechanical and ATR-FTIR analyses showed significant positive correlation between collagen maturity and stiffness. Diabetes decreased collagen maturation and the mineral deposition process, thus reducing biomechanical properties. Moreover, the study showed that HBO improved crosslink maturation and increased maximum strength and stiffness in the femur of T1DM animals.

  14. Circulating matrix metalloproteinases are associated with arterial stiffness in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Peeters, Stijn A.; Engelen, Lian; Buijs, Jacqueline

    2017-01-01

    BACKGROUND: Altered regulation of extracellular matrix (ECM) composition by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) may contribute to arterial stiffening. We investigated associations between circulating MMP-1, -2, -3, -9, -10 and TIMP-1, and carotid......). Linear regression analyses were used to investigate cross-sectional associations between circulating levels of MMP-1, -2, -3, -9, -10, and TIMP-1 and cfPWV (n = 614) as well as office PP (n = 1517). Data on 24-h brachial and 24-h central PP were available in 638 individuals from PROFIL. Analyses were...... was associated with cfPWV [β per 1 SD higher lnMMP3 0.29 m/s (0.02; 0.55)]. In addition, brachial and central 24-h PP measurements in PROFIL were significantly associated with MMP-2 [(1.40 (0.47:2.33) and 1.43 (0.63:2.23)]. Pooled data analysis showed significant associations of circulating levels of MMP-1...

  15. Characterization of membrane association of Rinderpest virus matrix protein

    International Nuclear Information System (INIS)

    Subhashri, R.; Shaila, M.S.

    2007-01-01

    Paramyxovirus matrix protein is believed to play a crucial role in the assembly and maturation of the virus particle by bringing the major viral components together at the budding site in the host cell. The membrane association capability of many enveloped virus matrix proteins has been characterized to be their intrinsic property. In this work, we have characterized the membrane association of Rinderpest virus matrix (M) protein. The M protein of Rinderpest virus when expressed in the absence of other viral proteins is present both in the cytoplasm and plasma membrane. When expressed as GFP fusion protein, the M protein gets localized into plasma membrane protrusions. High salt and alkaline conditions resulted in partial dissociation of M protein from cell membrane. Thus, M protein behaves like an integral membrane protein although its primary structure suggests it to be a peripheral membrane protein

  16. Matrix Degradation in Human Immunodeficiency Virus Type 1-Associated Tuberculosis and Tuberculosis Immune Reconstitution Inflammatory Syndrome: A Prospective Observational Study.

    Science.gov (United States)

    Walker, Naomi F; Wilkinson, Katalin A; Meintjes, Graeme; Tezera, Liku B; Goliath, Rene; Peyper, Janique M; Tadokera, Rebecca; Opondo, Charles; Coussens, Anna K; Wilkinson, Robert J; Friedland, Jon S; Elkington, Paul T

    2017-07-01

    Extensive immunopathology occurs in human immunodeficiency virus (HIV)/tuberculosis (TB) coinfection, but the underlying molecular mechanisms are not well-defined. Excessive matrix metalloproteinase (MMP) activity is emerging as a key process but has not been systematically studied in HIV-associated TB. We performed a cross-sectional study of matrix turnover in HIV type 1 (HIV-1)-infected and -uninfected TB patients and controls, and a prospective cohort study of HIV-1-infected TB patients at risk of TB immune reconstitution inflammatory syndrome (TB-IRIS), in Cape Town, South Africa. Sputum and plasma MMP concentrations were quantified by Luminex, plasma procollagen III N-terminal propeptide (PIIINP) by enzyme-linked immunosorbent assay, and urinary lipoarabinomannan (LAM) by Alere Determine TB LAM assay. Peripheral blood mononuclear cells from healthy donors were cultured with Mycobacterium tuberculosis and extracellular matrix in a 3D model of TB granuloma formation. MMP activity differed between HIV-1-infected and -uninfected TB patients and corresponded with specific TB clinical phenotypes. HIV-1-infected TB patients had reduced pulmonary MMP concentrations, associated with reduced cavitation, but increased plasma PIIINP, compared to HIV-1-uninfected TB patients. Elevated extrapulmonary extracellular matrix turnover was associated with TB-IRIS, both before and during TB-IRIS onset. The predominant collagenase was MMP-8, which was likely neutrophil derived and M. tuberculosis-antigen driven. Mycobacterium tuberculosis-induced matrix degradation was suppressed by the MMP inhibitor doxycycline in vitro. MMP activity in TB differs by HIV-1 status and compartment, and releases matrix degradation products. Matrix turnover in HIV-1-infected patients is increased before and during TB-IRIS, informing novel diagnostic strategies. MMP inhibition is a potential host-directed therapy strategy for prevention and treatment of TB-IRIS. © The Author 2017. Published by Oxford

  17. Cell membrane integrity in myotonic dystrophy type 1: implications for therapy

    NARCIS (Netherlands)

    Gonzalez, A.M.M.; Kranzen, J.; Croes, H.J.E.; Bijl, S.; Broek, W.J.A.A. van den; Kessel, I.D.G. van; Engelen, B.G.M. van; Deutekom, J.C. van; Wieringa, B.; Mulders, S.A.; Wansink, D.G.

    2015-01-01

    Myotonic Dystrophy type 1 (DM1) is a multisystemic disease caused by toxic RNA from a DMPK gene carrying an expanded (CTG*CAG)n repeat. Promising strategies for treatment of DM1 patients are currently being tested. These include antisense oligonucleotides and drugs for elimination of expanded RNA or

  18. A Human Nuclear Shuttling Protein That Interacts with Human Immunodeficiency Virus Type 1 Matrix Is Packaged into Virions

    Science.gov (United States)

    Gupta, Kalpana; Ott, David; Hope, Thomas J.; Siliciano, Robert F.; Boeke, Jef D.

    2000-01-01

    Active nuclear import of the human immunodeficiency virus type 1 (HIV-1) preintegration complex (PIC) is essential for the productive infection of nondividing cells. Nuclear import of the PIC is mediated by the HIV-1 matrix protein, which also plays several critical roles during viral entry and possibly during virion production facilitating the export of Pr55Gag and genomic RNA. Using a yeast two-hybrid screen, we identified a novel human virion-associated matrix-interacting protein (VAN) that is highly conserved in vertebrates and expressed in most human tissues. Its expression is upregulated upon activation of CD4+ T cells. VAN is efficiently incorporated into HIV-1 virions and, like matrix, shuttles between the nucleus and cytoplasm. Furthermore, overexpression of VAN significantly inhibits HIV-1 replication in tissue culture. We propose that VAN regulates matrix nuclear localization and, by extension, both nuclear import of the PIC and export of Pr55Gag and viral genomic RNA during virion production. Our data suggest that this regulatory mechanism reflects a more global process for regulation of nucleocytoplasmic transport. PMID:11090181

  19. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

    Science.gov (United States)

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

    2000-01-01

    BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum.
RESULTS—Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes.
CONCLUSIONS—AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.


Keywords: liver/kidney microsomal antibody type 1; autoimmunity; autoimmune hepatitis; hepatitis C virus infection; confocal microscopy PMID:10716687

  20. Mixed-matrix membrane adsorbers for protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Z.; Wessling, M.

    2003-01-01

    The separation of two similarly sized proteins, bovine serum albumin (BSA) and bovine hemoglobin (Hb) was carried out using a new type of ion-exchange mixed-matrix adsorber membranes. The adsorber membranes were prepared by incorporation of various types of Lewatit ion-exchange resins into an

  1. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

    OpenAIRE

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

    2000-01-01

    BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confo...

  2. Plasma matrix metalloproteinases are associated with incident cardiovascular disease and all-cause mortality in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Peeters, S A; Engelen, L; Buijs, J

    2017-01-01

    BACKGROUND: Altered regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1...... differences in plasma MMP-1, -2, -3, -9, -10, and TIMP-1-levels in patients with and without a cardiovascular event and in those who died vs survivors. All analyses were adjusted for age, sex, duration of diabetes, HbA1c, nephropathy and for other conventional cardiovascular risk factors. RESULTS: After...... adjustment for potential confounders, higher MMP-2 plasma levels were significantly associated with higher incidence of cardiovascular events [HR 1.49 (95% CI 1.11; 1.99)], and higher plasma levels of MMP-1 [1.38 (1.07; 1.78)], MMP-2 [1.60 (1.19; 2.15)] and MMP-3 [1.39 (1.05; 1.85)] were associated with all...

  3. Type-1 cannabinoid receptors reduce membrane fluidity of capacitated boar sperm by impairing their activation by bicarbonate.

    Directory of Open Access Journals (Sweden)

    Barbara Barboni

    Full Text Available BACKGROUND: Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and stimulating molecules. METHODOLOGY/PRINCIPAL FINDINGS: In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate in the presence or in the absence of methanandamide (Met-AEA, a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716 or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP. By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity and on membrane enriched fraction (C/P content and anisotropy. CONCLUSIONS/SIGNIFICANCE: Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility.

  4. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Sanip, S.M.; Ismail, A.F.; Goh, P.S.; Norrdin, M.N.A.; Soga, T.; Tanemura, M.; Yasuhiko, H.

    2011-01-01

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  5. Recent advances on mixed matrix membranes for CO2 separation

    Institute of Scientific and Technical Information of China (English)

    Ming Wang; Zhi Wang; Song Zhao; Jixiao Wang; Shichang Wang

    2017-01-01

    Recent advances on mixed matrix membrane for CO2 separation are reviewed in this paper. To improve CO2 separation performance of polymer membranes, mixedmatrixmembranes (MMMs) are developed. The concept of MMM is illustrated distinctly. Suitable polymer and inorganic or organic fillers for MMMs are summarized.Possible interface morphologies between polymer and filler, and the effect of interface morphologies on gas transport properties of MMMs are summarized. The methods to improve compatibility between polymer and filler are introduced. There are eightmethods including silane coupling, Grignard treatment, incorporation of additive,grafting, in situ polymerization, polydopamine coating, particle fusion approach and polymer functionalization. To achieve higher productivity for industrial application,mixed matrix composite membranes are developed. The recent development on hollow fiber and flat mixedmatrix composite membrane is reviewed in detail. Last, the future trend of MMM is forecasted.

  6. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junfen, E-mail: junfensun@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, North People Road 2999, Shanghai 201620 (China); Wu, Lishun [Department of Chemistry and Chemical Engineering, Heze University, Daxue Road 2269, Heze, Shandong Province 274015 (China)

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  7. Membrane Estrogen Receptor-α Interacts with Metabotropic Glutamate Receptor Type 1a to Mobilize Intracellular Calcium in Hypothalamic Astrocytes

    Science.gov (United States)

    Kuo, John; Hariri, Omid R.; Bondar, Galyna; Ogi, Julie; Micevych, Paul

    2009-01-01

    Estradiol, acting on a membrane-associated estrogen receptor-α (mERα), induces an increase in free cytoplasmic calcium concentration ([Ca2+]i) needed for progesterone synthesis in hypothalamic astrocytes. To determine whether rapid estradiol signaling involves an interaction of mERα with metabotropic glutamate receptor type 1a (mGluR1a), changes in [Ca2+]i were monitored with the calcium indicator, Fluo-4 AM, in primary cultures of female postpubertal hypothalamic astrocytes. 17β-Estradiol over a range of 1 nm to 100 nm induced a maximal increase in [Ca2+]i flux measured as a change in relative fluorescence [ΔF Ca2+ = 615 ± 36 to 641 ± 47 relative fluorescent units (RFU)], whereas 0.1 nm of estradiol stimulated a moderate [Ca2+]i increase (275 ± 16 RFU). The rapid estradiol-induced [Ca2+]i flux was blocked with 1 μm of the estrogen receptor antagonist ICI 182,780 (635 ± 24 vs. 102 ± 11 RFU, P estradiol-induced membrane signaling in astrocytes. PMID:18948402

  8. Hybrid and Mixed Matrix Membranes for Separations from Fermentations

    Directory of Open Access Journals (Sweden)

    Christopher John Davey

    2016-02-01

    Full Text Available Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s, Greater understanding of the compatibility between the polymer and inorganic phase(s, Improved methods for homogeneously dispersing the inorganic phase.

  9. Hybrid and Mixed Matrix Membranes for Separations from Fermentations.

    Science.gov (United States)

    Davey, Christopher John; Leak, David; Patterson, Darrell Alec

    2016-02-29

    Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs) for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s), Greater understanding of the compatibility between the polymer and inorganic phase(s), Improved methods for homogeneously dispersing the inorganic phase.

  10. High levels of γ-H2AX foci and cell membrane oxidation in adolescents with type 1 diabetes

    International Nuclear Information System (INIS)

    Giovannini, Caterina; Piaggi, Simona; Federico, Giovanni; Scarpato, Roberto

    2014-01-01

    Highlights: • We aimed to detect signs of very early damage in peripheral cells of T1DM adolescents. • T1DM patients had high levels of oxidized cells and reduced expression of iNOS and NO. • Highly mutagenic lesions were markedly increased in the diabetic group, mainly in females. • The observed damage might increase the risk of cancer in the patients later in life. - Abstract: Oxidative stress caused by an excess of free radicals is implicated in the pathogenesis and development of type 1 diabetes mellitus (T1DM) and, in turn, it can lead to genome damage, especially in the form of DNA double-strand break (DSB). The DNA DSB is a potentially carcinogenic lesion for human cells. Thus, we aimed to evaluate whether the level of oxidative stress was increased in peripheral blood lymphocytes of a group of affected adolescents. In 35 T1DM adolescents and 19 healthy controls we assessed: (1) spontaneous and H 2 O 2 -induced oxidation of cell membrane using a fluorescence lipid probe; (2) spontaneous and LPS-induced expression of iNOS protein and indirect NO determination via cytofluorimetric analysis of O 2 − ; (3) immunofluorescent detection of the basal level of histone H2AX phosphorylation (γ-H2AX foci), a well-validated marker of DNA DSB. In T1DM, the frequencies of oxidized cells, both spontaneous and H 2 O 2 -induced (47.13 ± 0.02) were significantly higher than in controls (35.90 ± 0.03). Patients showed, in general, both a reduced iNOS expression and production of NO. Furthermore, the level of spontaneous nuclear damage, quantified as γ-H2AX foci, was markedly increased in T1DM adolescents (6.15 ± 1.08% of γ-H2AX + cells; 8.72 ± 2.14 γ-H2AXF/n; 9.26 ± 2.37 γ-H2AXF/np), especially in females. In the present study, we confirmed the role that oxidative stress plays in the disease damaging lipids of cell membrane and, most importantly, causing genomic damage in circulating white blood cells of affected adolescents. This also indicates that

  11. High levels of γ-H2AX foci and cell membrane oxidation in adolescents with type 1 diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Giovannini, Caterina [Unità di Genetica, Dipartimento di Biologia, Pisa University, Pisa (Italy); Piaggi, Simona [Sezione di Patologia Sperimentale, Dipartimento di Ricerca Traslazionale e delle Nuove Tecnologie in Medicina e Chirurgia, Pisa University, Pisa (Italy); Federico, Giovanni [Unità di Endocrinologia Pediatrica e Diabete, Dipartimento di Medicina Clinica e Sperimentale Pisa University, Pisa (Italy); Scarpato, Roberto, E-mail: roberto.scarpato@unipi.it [Unità di Genetica, Dipartimento di Biologia, Pisa University, Pisa (Italy)

    2014-12-15

    Highlights: • We aimed to detect signs of very early damage in peripheral cells of T1DM adolescents. • T1DM patients had high levels of oxidized cells and reduced expression of iNOS and NO. • Highly mutagenic lesions were markedly increased in the diabetic group, mainly in females. • The observed damage might increase the risk of cancer in the patients later in life. - Abstract: Oxidative stress caused by an excess of free radicals is implicated in the pathogenesis and development of type 1 diabetes mellitus (T1DM) and, in turn, it can lead to genome damage, especially in the form of DNA double-strand break (DSB). The DNA DSB is a potentially carcinogenic lesion for human cells. Thus, we aimed to evaluate whether the level of oxidative stress was increased in peripheral blood lymphocytes of a group of affected adolescents. In 35 T1DM adolescents and 19 healthy controls we assessed: (1) spontaneous and H{sub 2}O{sub 2}-induced oxidation of cell membrane using a fluorescence lipid probe; (2) spontaneous and LPS-induced expression of iNOS protein and indirect NO determination via cytofluorimetric analysis of O{sub 2}{sup −}; (3) immunofluorescent detection of the basal level of histone H2AX phosphorylation (γ-H2AX foci), a well-validated marker of DNA DSB. In T1DM, the frequencies of oxidized cells, both spontaneous and H{sub 2}O{sub 2}-induced (47.13 ± 0.02) were significantly higher than in controls (35.90 ± 0.03). Patients showed, in general, both a reduced iNOS expression and production of NO. Furthermore, the level of spontaneous nuclear damage, quantified as γ-H2AX foci, was markedly increased in T1DM adolescents (6.15 ± 1.08% of γ-H2AX{sup +} cells; 8.72 ± 2.14 γ-H2AXF/n; 9.26 ± 2.37 γ-H2AXF/np), especially in females. In the present study, we confirmed the role that oxidative stress plays in the disease damaging lipids of cell membrane and, most importantly, causing genomic damage in circulating white blood cells of affected adolescents

  12. SYNTHESIS AND CHARACTERIZATION OF POLYIMIDE-ZEOLITE MIXED MATRIX MEMBRANE

    Directory of Open Access Journals (Sweden)

    Budiyono Budiyono

    2012-02-01

    Full Text Available Biogas has become an attractive alternative energy source due to the limitation of energy from fossil. In this study, a new type of mixed matrix membrane (MMM consisting of polyimide-zeolite was synthesized and characterized for biogas purification. The MMM consists of medium concentration of polymer (20% wt polyimide, 80% N-Methyl-2-pyrrolidone (NMP and 25% zeolite 4A in total solid were prepared by a dry/wet phase inversion technique.  The fabricated MMM was characterized using SEM, DSC, TGA and gas permeation. Post treatment coating procedure was also conducted. The research showed that surface coating by 3% silicone rubber toward MMM PI 20% gave the significant effect to improve membrane selectivity. The ideal selectivity for CO2/CH4 separation increased from 0.99 for before coating to 7.9 after coating for PI-Zeolite MMM, respectively. The results suggest that PI-Zeolite MMM with good post treatment procedure will increase the membrane selectivity and permeability with more saver polymer requirement as well as energy saving due to low energy for mixing.

  13. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-01-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high

  14. Phase separation of the plasma membrane in human red blood cells as a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Giuseppe Maulucci

    Full Text Available Glycosylation, oxidation and other post-translational modifications of membrane and transmembrane proteins can alter lipid density, packing and interactions, and are considered an important factor that affects fluidity variation in membranes. Red blood cells (RBC membrane physical state, showing pronounced alterations in Type 1 diabetes mellitus (T1DM, could be the ideal candidate for monitoring the disease progression and the effects of therapies. On these grounds, the measurement of RBC membrane fluidity alterations can furnish a more sensitive index in T1DM diagnosis and disease progression than Glycosylated hemoglobin (HbA1c, which reflects only the information related to glycosylation processes. Here, through a functional two-photon microscopy approach we retrieved fluidity maps at submicrometric scale in RBC of T1DM patients with and without complications, detecting an altered membrane equilibrium. We found that a phase separation between fluid and rigid domains occurs, triggered by systemic effects on membranes fluidity of glycation and oxidation. The phase separation patterns are different among healthy, T1DM and T1DM with complications patients. Blood cholesterol and LDL content are positively correlated with the extent of the phase separation patterns. To quantify this extent a machine learning approach is employed to develop a Decision-Support-System (DSS able to recognize different fluidity patterns in RBC. Preliminary analysis shows significant differences(p<0.001 among healthy, T1DM and T1DM with complications patients. The development of an assay based on Phase separation of the plasma membrane of the Red Blood cells is a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus, and could allow customization and the selection of medical treatments in T1DM in clinical settings, and enable the early detection of complications.

  15. Phase separation of the plasma membrane in human red blood cells as a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus.

    Science.gov (United States)

    Maulucci, Giuseppe; Cordelli, Ermanno; Rizzi, Alessandro; De Leva, Francesca; Papi, Massimiliano; Ciasca, Gabriele; Samengo, Daniela; Pani, Giovambattista; Pitocco, Dario; Soda, Paolo; Ghirlanda, Giovanni; Iannello, Giulio; De Spirito, Marco

    2017-01-01

    Glycosylation, oxidation and other post-translational modifications of membrane and transmembrane proteins can alter lipid density, packing and interactions, and are considered an important factor that affects fluidity variation in membranes. Red blood cells (RBC) membrane physical state, showing pronounced alterations in Type 1 diabetes mellitus (T1DM), could be the ideal candidate for monitoring the disease progression and the effects of therapies. On these grounds, the measurement of RBC membrane fluidity alterations can furnish a more sensitive index in T1DM diagnosis and disease progression than Glycosylated hemoglobin (HbA1c), which reflects only the information related to glycosylation processes. Here, through a functional two-photon microscopy approach we retrieved fluidity maps at submicrometric scale in RBC of T1DM patients with and without complications, detecting an altered membrane equilibrium. We found that a phase separation between fluid and rigid domains occurs, triggered by systemic effects on membranes fluidity of glycation and oxidation. The phase separation patterns are different among healthy, T1DM and T1DM with complications patients. Blood cholesterol and LDL content are positively correlated with the extent of the phase separation patterns. To quantify this extent a machine learning approach is employed to develop a Decision-Support-System (DSS) able to recognize different fluidity patterns in RBC. Preliminary analysis shows significant differences(pBlood cells is a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus, and could allow customization and the selection of medical treatments in T1DM in clinical settings, and enable the early detection of complications.

  16. Human Immunodeficiency Virus Type 1 Nef protein modulates the lipid composition of virions and host cell membrane microdomains

    Directory of Open Access Journals (Sweden)

    Geyer Matthias

    2007-10-01

    Full Text Available Abstract Background The Nef protein of Human Immunodeficiency Viruses optimizes viral spread in the infected host by manipulating cellular transport and signal transduction machineries. Nef also boosts the infectivity of HIV particles by an unknown mechanism. Recent studies suggested a correlation between the association of Nef with lipid raft microdomains and its positive effects on virion infectivity. Furthermore, the lipidome analysis of HIV-1 particles revealed a marked enrichment of classical raft lipids and thus identified HIV-1 virions as an example for naturally occurring membrane microdomains. Since Nef modulates the protein composition and function of membrane microdomains we tested here if Nef also has the propensity to alter microdomain lipid composition. Results Quantitative mass spectrometric lipidome analysis of highly purified HIV-1 particles revealed that the presence of Nef during virus production from T lymphocytes enforced their raft character via a significant reduction of polyunsaturated phosphatidylcholine species and a specific enrichment of sphingomyelin. In contrast, Nef did not significantly affect virion levels of phosphoglycerolipids or cholesterol. The observed alterations in virion lipid composition were insufficient to mediate Nef's effect on particle infectivity and Nef augmented virion infectivity independently of whether virus entry was targeted to or excluded from membrane microdomains. However, altered lipid compositions similar to those observed in virions were also detected in detergent-resistant membrane preparations of virus producing cells. Conclusion Nef alters not only the proteome but also the lipid composition of host cell microdomains. This novel activity represents a previously unrecognized mechanism by which Nef could manipulate HIV-1 target cells to facilitate virus propagation in vivo.

  17. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.; Ghosh, Asim K.; Huang, Xiaofei; Liong, Monty; Zink, Jeffrey I.

    2011-01-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  18. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.

    2011-12-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  19. Integrated Water Gas Shift Membrane Reactors Utilizing Novel, Non Precious Metal Mixed Matrix Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, John P. [Univ. of Texas-Dallas, Richardson, TX (United States). Dept. of Chemistry

    2013-09-30

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed- matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H2/CO2 selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO2-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethanol diamine resulted in an increase in H2/CO2 selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncross-linked polymer. Performance of the polybenzimidazole (PBI) hollow fibers prepared at Santa Fe Science and Technology (SFST, Inc.) showed increased flux and selectivity at 300 °C, which is comparable to a flat PBI membrane. A water-gas shift reactor has been built and currently being optimized for testing under DOE conditions.

  20. Cholesterol trafficking and raft-like membrane domain composition mediate scavenger receptor class B type 1-dependent lipid sensing in intestinal epithelial cells.

    Science.gov (United States)

    Morel, Etienne; Ghezzal, Sara; Lucchi, Géraldine; Truntzer, Caroline; Pais de Barros, Jean-Paul; Simon-Plas, Françoise; Demignot, Sylvie; Mineo, Chieko; Shaul, Philip W; Leturque, Armelle; Rousset, Monique; Carrière, Véronique

    2018-02-01

    Scavenger receptor Class B type 1 (SR-B1) is a lipid transporter and sensor. In intestinal epithelial cells, SR-B1-dependent lipid sensing is associated with SR-B1 recruitment in raft-like/ detergent-resistant membrane domains and interaction of its C-terminal transmembrane domain with plasma membrane cholesterol. To clarify the initiating events occurring during lipid sensing by SR-B1, we analyzed cholesterol trafficking and raft-like domain composition in intestinal epithelial cells expressing wild-type SR-B1 or the mutated form SR-B1-Q445A, defective in membrane cholesterol binding and signal initiation. These features of SR-B1 were found to influence both apical cholesterol efflux and intracellular cholesterol trafficking from plasma membrane to lipid droplets, and the lipid composition of raft-like domains. Lipidomic analysis revealed likely participation of d18:0/16:0 sphingomyelin and 16:0/0:0 lysophosphatidylethanolamine in lipid sensing by SR-B1. Proteomic analysis identified proteins, whose abundance changed in raft-like domains during lipid sensing, and these included molecules linked to lipid raft dynamics and signal transduction. These findings provide new insights into the role of SR-B1 in cellular cholesterol homeostasis and suggest molecular links between SR-B1-dependent lipid sensing and cell cholesterol and lipid droplet dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Extracellular Matrix Regulations of Membrane Type 1 - Matrix Metalloproteinasis (MT1-MMP) and Matrix Metalloproteinase-2 (MMP-2) in Human Breast Fibroblasts

    National Research Council Canada - National Science Library

    Harnandez-Barrantes, Sonia

    2001-01-01

    .... Thus, under certain conditions, TIMP-2 is a positive regulator of MMP activity. TIMP-4, a close homologue of TIMP-2 also binds to pro-MMP- 2 and can potentially participate in pro-MMP-2 activation...

  2. An investigation on polymeric blend mixed matrix membranes of ...

    African Journals Online (AJOL)

    Polymeric membranes have been vastly used for gas separation purposes however they have an upper-bound trade off problem which is the reason why this research work is focusing on inorganic filler added to polymer blend membranes to enhance the selectivity and permeability of the resulted membranes. Different ...

  3. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    Science.gov (United States)

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  4. Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation

    Science.gov (United States)

    The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally c...

  5. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao; Pan, Yichang; Peinemann, Klaus-Viktor; Lai, Zhiping

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite

  6. FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

    Directory of Open Access Journals (Sweden)

    A. F. Ismail

    2012-01-01

    Full Text Available This study is performed primarily to investigate the feasibility of fumed silica as inorganic material towards gas separation performance of mixed matrix membrane. In this study, polyimide/polyethersulfone (PES-fumed silica mixed matrix membranes were casted using dry/wet technique. The results from the FESEM, DSC and FTIR analysis confirmed that the structure and physical properties of membrane is influenced by inorganic filler. FESEM’s cross-section view indicated good compatibility between polymer and fumed silica for all of range fumed silica used in this study. The gas separation performance of the mixed matrix membranes with fumed silica were relatively higher compared to that of the neat PI/PES membrane. PI/PES-fumed silica 5 wt% yielded significant selectivity enhancement of 7.21 and 40.47 for O2/N2, and CO2/CH4, respectively.

  7. Nanoclay embedded mixed matrix PVDF nanocomposite membrane: Preparation, characterization and biofouling resistance

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, Hamid [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Department of Civil Engineering, Razi University, 67149 Kermanshah (Iran, Islamic Republic of); Ghaemi, Negin, E-mail: negin_ghaemi@kut.ac.ir [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Madaeni, Sayed S. [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Daraei, Parisa [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Khadivi, Mohammad Ali [Friedrich-Alexander University, Erlangen-Nuremberg, Egerland Strasse 3, D-91058 Erlangen (Germany); Falsafi, Monir [Department of Chemistry, Faculty of Science, Razi University, 67149 Kermanshah (Iran, Islamic Republic of)

    2014-09-15

    Highlights: • Nanocomposite membranes were prepared by addition of OMMT to PVDF membrane. • Addition of nanoclay considerably increased the hydrophilicity of PVDF membrane. • Nanocomposite membranes had higher water flux and antifouling properties. • Fouling of membranes blended with nanoclay (<4 wt.%) reduced. - Abstract: In this paper, nanocomposite PVDF/nanoclay membranes were prepared with addition of different concentrations of organically modified montmorillonite (OMMT) into the polymeric casting solution using combination of solution dispersion and phase inversion methods. Membranes were characterized by use of X-ray diffraction (XRD), water contact angle, scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their performances were evaluated in terms of pure water flux and fouling parameters. The surface hydrophilicity of all nanocomposites markedly improved compared to nascent PVDF. In addition, XRD patterns revealed the formation of intercalated layers of mineral clays in PVDF matrix. SEM and AFM images showed that addition of OMMT resulted in nanocomposite membranes with thinner skin layer and higher porosity rather than PVDF membranes. Pure water flux of PVDF/OMMT membranes increased significantly (particularly for fabricated membranes by 4 and 6 wt.% OMMT) compared to that of PVDF membrane. Moreover, nanocomposite membranes showed the elevated antifouling properties, and flux recovery of nascent PVDF membranes increased from 51 to 72% with addition of 2 wt.% OMMT nanoparticles. These nanocomposite membranes also offered a remarkable reusability and durability against biofouling.

  8. Nanoclay embedded mixed matrix PVDF nanocomposite membrane: Preparation, characterization and biofouling resistance

    International Nuclear Information System (INIS)

    Rajabi, Hamid; Ghaemi, Negin; Madaeni, Sayed S.; Daraei, Parisa; Khadivi, Mohammad Ali; Falsafi, Monir

    2014-01-01

    Highlights: • Nanocomposite membranes were prepared by addition of OMMT to PVDF membrane. • Addition of nanoclay considerably increased the hydrophilicity of PVDF membrane. • Nanocomposite membranes had higher water flux and antifouling properties. • Fouling of membranes blended with nanoclay (<4 wt.%) reduced. - Abstract: In this paper, nanocomposite PVDF/nanoclay membranes were prepared with addition of different concentrations of organically modified montmorillonite (OMMT) into the polymeric casting solution using combination of solution dispersion and phase inversion methods. Membranes were characterized by use of X-ray diffraction (XRD), water contact angle, scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their performances were evaluated in terms of pure water flux and fouling parameters. The surface hydrophilicity of all nanocomposites markedly improved compared to nascent PVDF. In addition, XRD patterns revealed the formation of intercalated layers of mineral clays in PVDF matrix. SEM and AFM images showed that addition of OMMT resulted in nanocomposite membranes with thinner skin layer and higher porosity rather than PVDF membranes. Pure water flux of PVDF/OMMT membranes increased significantly (particularly for fabricated membranes by 4 and 6 wt.% OMMT) compared to that of PVDF membrane. Moreover, nanocomposite membranes showed the elevated antifouling properties, and flux recovery of nascent PVDF membranes increased from 51 to 72% with addition of 2 wt.% OMMT nanoparticles. These nanocomposite membranes also offered a remarkable reusability and durability against biofouling

  9. Preparation of mixed matrix adsorber membranes for protein recovery

    NARCIS (Netherlands)

    Avramescu, M.E.; Girones nogue, Miriam; Borneman, Zandrie; Wessling, Matthias

    2003-01-01

    This paper presents a generic technology allowing the incorporation of functional entities into a porous substrate. Various ion exchange particles were incorporated into an ethylene vinyl alcohol (EVAL) copolymer porous matrix by an immersion phase separation process and a heterogeneous matrix,

  10. Zeolite-imidazolate framework (ZIF-8) membrane synthesis on a mixed-matrix substrate.

    Science.gov (United States)

    Barankova, Eva; Pradeep, Neelakanda; Peinemann, Klaus-Viktor

    2013-10-21

    A thin, dense, compact and hydrogen selective ZIF-8 membrane was synthesized on a polymer/metal oxide mixed-matrix support by a secondary seeding method. The new concept of incorporating ZnO particles into the support and PDMS coating of the ZIF-8 layer is introduced to improve the preparation of ZIF-polymer composite membranes.

  11. A metal ion charged mixed matrix membrane for selective adsorption of hemoglobin

    NARCIS (Netherlands)

    Tetala, K.K.R.; Skrzypek, K.; Levisson, M.; Stamatialis, D.F.

    2013-01-01

    In this work, we developed a mixed matrix membrane by incorporating 20–40 µm size iminodiacetic acid modified immobeads within porous Ethylene vinyl alcohol (EVAL) polymer matrix. The MMM were charged with copper ions for selective adsorption of bovine hemoglobin in presence of bovine serum albumin.

  12. A metal ion charged mixed matrix membrane for selective adsorption of hemoglobin

    NARCIS (Netherlands)

    Tetala, K.K.R.; Skrzypek, Katarzyna; Levisson, M.; Stamatialis, Dimitrios

    2013-01-01

    In this work, we developed a mixed matrix membrane by incorporating 20–40 μm size iminodiacetic acid modified immobeads within porous Ethylene vinyl alcohol (EVAL) polymer matrix. The MMM were charged with copper ions for selective adsorption of bovine hemoglobin in presence of bovine serum albumin.

  13. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    DEFF Research Database (Denmark)

    Toft-Hansen, Henrik; Babcock, Alicia A; Millward, Jason M

    2007-01-01

    BACKGROUND: Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (M...

  14. Highly scalable ZIF-based mixed-matrix hollow fiber membranes for advanced hydrocarbon separations

    KAUST Repository

    Zhang, Chen

    2014-05-29

    ZIF-8/6FDA-DAM, a proven mixed-matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual-layer ZIF-8/6FDA-DAM mixed-matrix hollow fiber membranes with ZIF-8 nanoparticle loading up to 30 wt % using the conventional dry-jet/wet-quench fiber spinning technique. The mixed-matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed-matrix dense films. Critical variables controlling successful formation of mixed-matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high-loading mixed-matrix hollow fiber membranes with significantly enhanced selectivity for separation of condensable olefin/paraffin mixtures. Therefore, it represents a major step in the research area of advanced mixed-matrix membranes. © 2014 American Institute of Chemical Engineers.

  15. Investigation of Electrochemical and Morphological Properties of Mixed Matrix Polysulfone-Silica Anion Exchange Membrane

    Directory of Open Access Journals (Sweden)

    Khoiruddin

    2016-02-01

    Full Text Available Mixed matrix anion exchange membranes (AEMs were synthesized using dry-wet phase inversion. The casting solutions were prepared by dispersing finely ground anion-exchange resin particles in N,N-dimethylacetamide (DMAc solutions of polysulfone (PSf. Subsequently, nanosilica particles were introduced into the membranes. The results show that evaporation time (tev and solution composition contributed to membrane properties formation. A longer tev produces membranes with reduced void fraction inside the membranes, thus the amount of water adsorbed and membrane conductivity are reduced. Meanwhile, the permselectivity was improved by increasing tev, since a longer tev produces membranes with a narrower channel for ion migration and more effective Donnan exclusion. The incorporation of 0.5 %-wt nanosilica particles into the polymer matrix led to conductivity improvement (from 2.27 to 3.41 mS.cm-1. This may be associated with additional pathway formation by hydroxyl groups on the silica surface that entraps water and assists ion migration. However, at further silica loading (1.0 and 1.5 %-wt, these properties decreased (to 1.9 and 1.4 mS.cm-1 respectively, which attributed to inaccessibility of ion-exchange functional groups due to membrane compactness. It was found from the results that nanosilica contributes to membrane formation (increases casting solution viscosity then reduces void fraction and membrane functional group addition (provides hydroxyl groups.

  16. M(atrix) theory on an orbifold and twisted membrane

    International Nuclear Information System (INIS)

    Kim, N.

    1997-01-01

    M(atrix) theory on an orbifold and classical two-branes therein are studied with particular emphasis on heterotic M(atrix) theory on S 1 / Z 2 relevant to strongly coupled heterotic and dual type IA string theories. By analyzing the orbifold condition on Chan-Paton factors, we show that three choices of gauge group are possible for heterotic M(atrix) theory: SO(2N), SO(2N+1) or USp(2N). By examining the area-preserving diffeomorphism that underlies the M(atrix) theory, we find that each choice of gauge group restricts the possible topologies of two-branes. The result suggests that only the choice of SO(2N) or SO(2N+1) allows open two-branes, and hence, is relevant to heterotic M(atrix) theory. We show that the requirement of both local vacuum energy cancellation and of world-sheet anomaly cancellation of the resulting heterotic string identifies supersymmetric twisted sector spectra with sixteen fundamental representation spinors from each of the two fixed points. Twisted open and closed two-brane configurations are obtained in the large N limit. (orig.)

  17. Mixed Matrix Composite Membranes Containing POSS Molecules for Carbon Dioxide Removal Application

    KAUST Repository

    Rini, Eki Listya

    2011-05-10

    CO2 removal by membrane processes is considerably potential for several applications such as natural gas and synthesis gas purification, enhanced oil recovery application, and carbon dioxide capture in combat against global warming. Dense polymeric membranes are commonly utilized for these type of gas separation applications. Nevertheless, the intrinsic properties of dense polymeric membranes, which commonly characterize by the low gas permeability versus high gas selectivity trade–off or vice versa, is less desirable. In order to meet the increased demand of CO2 removal, a strategy to improve the gas separation performance of a polymeric membrane is investigated in this study. With this regard, mixed matrix membranes in which inorganic non porous fillers are incorporated into a polymeric matrix were prepared to achieve the aforementioned objective. The mixed matrix membranes were prepared from Pebax® block copolymers and PEG POSS® molecules. These hybrid membranes were formed as both dense and multilayer composite membranes. The dense transparent membranes with well–dispersed fillers could be obtained by variation of the solvent mixture. The DSC analyses showed that incorporation of PEG POSS® into Pebax® matrix altered the thermal properties of the matrix. The multilayer composite membranes were then prepared from a PTMSP gutter layer deposited on a PAN porous support and an adjacent hybrid Pebax®/PEG POSS® as the top layer. These hybrid multilayer composite membranes exhibited an enhanced CO2 selectiv4 ity by a factor of two relative to the pure Pebax®. In these hybrid systems, the CO2 separation was presumably enhanced by the high ether oxides content from PEG POSS® that has high affinities for CO2. For particular composition of Pebax® and PEG POSS® concentrations, the PTMSP gutter layer harnessed the CO2 selectivity without losing the CO2 permeation rate. At the same time, these membrane, however, suffered severe adhesion between the gutter layer

  18. Rat hair follicle dermal papillae have an extracellular matrix containing basement membrane components

    DEFF Research Database (Denmark)

    Couchman, J R

    1986-01-01

    , to be replaced by synthesis of other components including type I and III collagens. It seems likely therefore that the dermal papilla cells in vivo synthesize a basement membrane type of extracellular matrix, although a contribution from epithelial, and in some cases capillary endothelial, cells cannot be ruled......Dermal papillae are small mesenchymally derived zones at the bases of hair follicles which have an important role in hair morphogenesis in the embryo and control of the hair growth cycle in postnatal mammals. The cells of the papilla are enmeshed in a dense extracellular matrix which undergoes...... extensive changes in concert with the hair cycle. Here it is shown that this matrix in anagen pelage follicles of postnatal rats contains an abundance of basement membrane components rather than dermal components such as interstitial collagens. In particular, type IV collagen, laminin, and basement membrane...

  19. Progress on Incorporating Zeolites in Matrimid®5218 Mixed Matrix Membranes towards Gas Separation

    Directory of Open Access Journals (Sweden)

    Roberto Castro-Muñoz

    2018-06-01

    Full Text Available Membranes, as perm-selective barriers, have been widely applied for gas separation applications. Since some time ago, pure polymers have been used mainly for the preparation of membranes, considering different kinds of polymers for such preparation. At this point, polyimides (e.g., Matrimid®5218 are probably one of the most considered polymers for this purpose. However, the limitation on the performance relationship of polymeric membranes has promoted their enhancement through the incorporation of different inorganic materials (e.g., zeolites into their matrix. Therefore, the aim of this work is to provide an overview about the progress of zeolite embedding in Matrimid®5218, aiming at the preparation of mixed matrix membranes for gas separation. Particular attention is paid to the relevant experimental results and current findings. Finally, we describe the prospects and future trends in the field.

  20. Zeolite-imidazolate framework (ZIF-8) membrane synthesis on a mixed-matrix substrate

    KAUST Repository

    Barankova, Eva; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2013-01-01

    A thin, dense, compact and hydrogen selective ZIF-8 membrane was synthesized on a polymer/metal oxide mixed-matrix support by a secondary seeding method. The new concept of incorporating ZnO particles into the support and PDMS coating of the ZIF-8 layer is introduced to improve the preparation of ZIF-polymer composite membranes. © 2013 The Royal Society of Chemistry.

  1. Studies on carboxylated graphene oxide incorporated polyetherimide mixed matrix ultrafiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kaleekkal, Noel Jacob, E-mail: noeljacob89@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India); Thanigaivelan, A., E-mail: thanichemstar@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India); Rana, Dipak, E-mail: rana@uottawa.ca [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Private, Ottawa, Ontario, K1N 6N5 (Canada); Mohan, D., E-mail: mohantarun@gmail.com [Membrane Laboratory, Department of Chemical Engineering, ACT, Anna University, Chennai, 600025 (India)

    2017-01-15

    In this work the graphene oxide prepared by the modified Hummers’ method was effectively carboxylated. These carboxylated graphene oxide (c-GO) microsheets was characterized by X-ray diffraction analysis, Raman shift, zeta potential, and their morphology was observed using a high resolution scanning/transmission electron microscopy. Polyetherimide mixed matrix membranes (MMMs) were fabricated by the non-solvent induced phase separation technique with varying concentration of this microsheet. The presence of these microsheets on the membrane surface was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy and could also be confirmed visually by optical images. The membranes were further characterized; they showed a greater water flux, higher porosity, and sufficient thermal stability. Incorporation of these microsheets improved the hydrophilicity of the membrane confirmed by the lower contact angle values, which in turn explained the lower interfacial free energy, the increase in work of adhesion, the higher solid-vapor free energy and the spreading coefficient. Membranes loaded with 0.3 wt% of c-GO showed a flux recovery of 94% and only a small flux decline even after 180 min of filtration of humic acid (HA) solution. The efficiency of these membranes in removal of HA, toxic metal ions was also investigated. The bacterial anti-adhesion property of c-GO in the membranes was also explored using Escherichia coli, as a model bio-foulant. The charge of the microsheets and their unique architecture imparts higher hydrophilicity and greater fouling resistance along with improved permeation flux when incorporated into the polymer matrix. - Highlights: • Novel membranes by incorporating carboxylated GO into polyetherimide matrix. • Modified membranes exhibited greater porosity, flux and high humic acid rejection. • Nanoplatelets improved the flux recovery ratio to >94%. • Liquid phase polymer based retention utilized for toxic heavy metal

  2. Immunization with r-Lactococcus lactis expressing outer membrane protein A of Shigella dysenteriae type-1: evaluation of oral and intranasal route of administration.

    Science.gov (United States)

    Yagnik, B; Sharma, D; Padh, H; Desai, P

    2017-02-01

    To evaluate the comparative immunogenic potential of food grade Lactococcus lactis expressing outer membrane protein A (OmpA) of Shigella dysenteriae type-1 (SD-1) when administered either orally or intranasally. OmpA of SD-1 was cloned and expressed first in Escherichia coli and then in L. lactis. Presence of recombinant gene was confirmed by restriction enzyme digestion and immunoblot analysis. Using immobilized metal affinity chromatography, OmpA was purified from recombinant E. coliBL21 (DE3) and subcutaneously administered in BALB/c mice. Detection of OmpA-specific IgG antibodies by enzyme-linked immunosorbent assay (ELISA) confirmed the immunogenicity of OmpA. In order to establish r-L. lactis as a mucosal delivery vehicle, it was administered orally and nasally in BALB/c mice. Serum IgG and faecal IgA were assessed through ELISA to compare the relative potential of immunization routes and immunogenic potential of r-L. lactis. Immunization via the oral route proved superior to intranasal exposure. Recombinant L. lactis expressing OmpA of SD-1 was found to be immunogenic. Oral administration of r-L. lactis elicited higher systemic and mucosal immune response when compared with the nasal route. Using food grade recombinant L. lactis has implications in the development of a prophylactic against multidrug-resistant Shigella, which can be used as a prospective vaccine candidate. Evaluating mucosal routes of immunization demonstrated that the oral route of administration elicited better immune response against OmpA of Shigella. © 2016 The Society for Applied Microbiology.

  3. Factors affecting alcohol-water pervaporation performance of hydrophobic zeolite-silicone rubber mixed matrix membranes

    Science.gov (United States)

    Mixed matrix membranes (MMMs) consisting of ZSM-5 zeolite particles dispersed in silicone rubber exhibited ethanol-water pervaporation permselectivities up to 5 times that of silicone rubber alone and 3 times higher than simple vapor-liquid equilibrium (VLE). A number of conditi...

  4. Mixed matrix membranes based on polyamide/montmorillonite for pervaporation of methanol-toluene mixture

    Czech Academy of Sciences Publication Activity Database

    Avagimova, N.; Polotskaya, G.; Saprykina, N.; Toikka, A.; Pientka, Zbyněk

    2013-01-01

    Roč. 48, č. 17 (2013), s. 2513-2523 ISSN 0149-6395 R&D Projects: GA ČR GA104/09/1165 Institutional support: RVO:61389013 Keywords : membranes * pervaporation * mixed matrix Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.200, year: 2013

  5. Pore formation mechanism of porous poly(DL-lactic acid) matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Phaechamud, Thawatchai, E-mail: tphaechamud011@yahoo.com; Chitrattha, Sasiprapa, E-mail: sasi_toey@hotmail.com

    2016-04-01

    Porous PLA structure has been widely used in cell transplantation, drug carrier and wound dressing. The porous structure can be controlled depending on the choice of the polymer, solvent, nonsolvent and preparation parameters. In this study, the porous PLA matrix membranes were prepared by adding PEG 400 in PLA solution using dichloromethane (DCM) as solvent prior to casting. The influence of other liquids as co-solvent on pore formation and the structural change during membrane formation were evaluated. The co-solvents affected both porous topography and mechanical properties of PLA membrane. The porous matrix were produced when the non-solvent of PLA was used as co-solvent. Cryo-SEM micrographs revealed that PEG 400 still remained in the PLA porous matrix membrane. From the tracking of the structural change during film formation, the PLA–PEG solution changed into porous structure by liquid liquid phase separation and solidification processes, respectively. Thermogravimetric analysis revealed that PLA–PEG in DCM solution exhibited the two-step of weight loss, the first step occurred from DCM evaporation and the second step occurred from the degradation of PLA–PEG matrix. The liquid–liquid phase separation and solidification started when the amount of DCM was higher than PEG 400 for 2.67 folds and DCM amount was equal to that of PEG 400, respectively. These results could clarify the pore formation mechanism of porous PLA membrane and will be useful for the further investigation and application. - Highlights: • Pore formation mechanism of PLA matrix membrane inducing by PEG 400 addition was investigated. • Cryo-scanning electron microscopy revealed the embedded PEG 400 in matrix membrane. • Tracking of structural change during membrane formation with stereomicroscope and thermogravimetric analysis could explain the pore formation mechanism. • Liquid-liquid phase separation of PLA-PEG 400 solution started when the amount of dichloromethane remained 2

  6. Pore formation mechanism of porous poly(DL-lactic acid) matrix membrane

    International Nuclear Information System (INIS)

    Phaechamud, Thawatchai; Chitrattha, Sasiprapa

    2016-01-01

    Porous PLA structure has been widely used in cell transplantation, drug carrier and wound dressing. The porous structure can be controlled depending on the choice of the polymer, solvent, nonsolvent and preparation parameters. In this study, the porous PLA matrix membranes were prepared by adding PEG 400 in PLA solution using dichloromethane (DCM) as solvent prior to casting. The influence of other liquids as co-solvent on pore formation and the structural change during membrane formation were evaluated. The co-solvents affected both porous topography and mechanical properties of PLA membrane. The porous matrix were produced when the non-solvent of PLA was used as co-solvent. Cryo-SEM micrographs revealed that PEG 400 still remained in the PLA porous matrix membrane. From the tracking of the structural change during film formation, the PLA–PEG solution changed into porous structure by liquid liquid phase separation and solidification processes, respectively. Thermogravimetric analysis revealed that PLA–PEG in DCM solution exhibited the two-step of weight loss, the first step occurred from DCM evaporation and the second step occurred from the degradation of PLA–PEG matrix. The liquid–liquid phase separation and solidification started when the amount of DCM was higher than PEG 400 for 2.67 folds and DCM amount was equal to that of PEG 400, respectively. These results could clarify the pore formation mechanism of porous PLA membrane and will be useful for the further investigation and application. - Highlights: • Pore formation mechanism of PLA matrix membrane inducing by PEG 400 addition was investigated. • Cryo-scanning electron microscopy revealed the embedded PEG 400 in matrix membrane. • Tracking of structural change during membrane formation with stereomicroscope and thermogravimetric analysis could explain the pore formation mechanism. • Liquid-liquid phase separation of PLA-PEG 400 solution started when the amount of dichloromethane remained 2

  7. Nano-ZnO embedded mixed matrix polyethersulfone (PES) membrane: Influence of nanofiller shape on characterization and fouling resistance

    International Nuclear Information System (INIS)

    Rajabi, Hamid; Ghaemi, Negin; Madaeni, Sayed S.; Daraei, Parisa; Astinchap, Bandar; Zinadini, Sirus; Razavizadeh, Sayed Hossein

    2015-01-01

    Graphical abstract: - Highlights: • ZnO nanofillers with different shape (nanorod and nanoparticle) were synthesized. • Mixed matrix PES membranes were fabricated by different concentrations of nanofillers. • Embedding nanofillers affected on morphology and hydrophilicity of PES membranes. • Nanorod MM membranes revealed the highest water flux and antifouling characteristic. • ZnO nanorod-embedded membrane showed an acceptable reusability and durability. - Abstract: Two different kinds of nano-ZnO (nanoparticle and nanorod) were synthesized, characterized, and embedded in a PES membrane matrix to investigate the effects of a nanofiller shape on the mixed matrix membrane characteristics and the antifouling capability. The mixed matrix membranes were fabricated by mixing different amounts of nanofillers with dope solution followed by a phase inversion precipitation technique. The effect of the shape of the embedded nanofillers on the morphology and performance of the fabricated membranes was studied in terms of pure water flux, fouling resistance, hydrophilicity, surface, and bulk morphology by means of permeation tests, milk powder solution filtration, water contact angle and porosity measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. Water flux of the mixed matrix membranes significantly improved after the addition of both types of ZnO nanofillers due to a higher hydrophilicity and porosity of the prepared membranes. The water contact angle measurements confirmed the increased hydrophilicity of the modified membranes, particularly in the ZnO nanorod mixed membranes. Fouling resistance of the membranes assessed by powder milk solution filtration revealed that 0.1 wt% ZnO nanorod membrane has the best antifouling property. The prepared mixed matrix membranes embedded with 0.1 wt% of both types of ZnO nanofillers showed a remarkable durability and reusability during the filtration tests; however, the best

  8. Nano-ZnO embedded mixed matrix polyethersulfone (PES) membrane: Influence of nanofiller shape on characterization and fouling resistance

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, Hamid [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Department of Civil Engineering, Razi University, 67149 Kermanshah (Iran, Islamic Republic of); Ghaemi, Negin, E-mail: negin_ghaemi@kut.ac.ir [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Madaeni, Sayed S. [Membrane Research Centre, Department of Chemical Engineering, Razi University, Tagh Bostan, 67149 Kermanshah (Iran, Islamic Republic of); Daraei, Parisa [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of); Astinchap, Bandar [Physics Department, Faculty of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Zinadini, Sirus [Water and Wastewater Research Center (WWRC), Department of Applied Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Razavizadeh, Sayed Hossein [Department of Chemical Engineering, Kermanshah University of Technology, 67178 Kermanshah (Iran, Islamic Republic of)

    2015-09-15

    Graphical abstract: - Highlights: • ZnO nanofillers with different shape (nanorod and nanoparticle) were synthesized. • Mixed matrix PES membranes were fabricated by different concentrations of nanofillers. • Embedding nanofillers affected on morphology and hydrophilicity of PES membranes. • Nanorod MM membranes revealed the highest water flux and antifouling characteristic. • ZnO nanorod-embedded membrane showed an acceptable reusability and durability. - Abstract: Two different kinds of nano-ZnO (nanoparticle and nanorod) were synthesized, characterized, and embedded in a PES membrane matrix to investigate the effects of a nanofiller shape on the mixed matrix membrane characteristics and the antifouling capability. The mixed matrix membranes were fabricated by mixing different amounts of nanofillers with dope solution followed by a phase inversion precipitation technique. The effect of the shape of the embedded nanofillers on the morphology and performance of the fabricated membranes was studied in terms of pure water flux, fouling resistance, hydrophilicity, surface, and bulk morphology by means of permeation tests, milk powder solution filtration, water contact angle and porosity measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. Water flux of the mixed matrix membranes significantly improved after the addition of both types of ZnO nanofillers due to a higher hydrophilicity and porosity of the prepared membranes. The water contact angle measurements confirmed the increased hydrophilicity of the modified membranes, particularly in the ZnO nanorod mixed membranes. Fouling resistance of the membranes assessed by powder milk solution filtration revealed that 0.1 wt% ZnO nanorod membrane has the best antifouling property. The prepared mixed matrix membranes embedded with 0.1 wt% of both types of ZnO nanofillers showed a remarkable durability and reusability during the filtration tests; however, the best

  9. Preparation of mixed matrix PES-based nanofiltration membrane filled with PANI-co-MWCNT composite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bagheripour, Ehsan; Moghadassi, Abdolreza; Hosseini, Sayed Mohsen [Faculty of Engineering, Arak University, Arak (Iran, Islamic Republic of)

    2016-04-15

    Mixed matrix polyethersulfone/PANI-co-MWCNTs composite nanoparticle nanofiltration membrane was prepared by casting solution technique. Polyvinylpyrrolidone was also used as membrane pore former in membrane fabrication. The effect of polyaniline-co-multi walled carbon nanotubes composite nanoparticle concentration in the casting solution on membrane structure and performance was investigated. Scanning optical microscopy and scanning electron microscopy, FTIR analysis, porosity, mean pore size, contact angle, water content, NaCl/Na2SO4 rejection, water flux, tensile strength measurements and 3D surface image were also carried out in membrane characterization. SOM images showed nanoparticle agglomeration at high additive loading ratio. SEM images showed the membrane sub-layer porosity and thickness were changed by use of nanoparticles in membrane matrix. The membrane water content, porosity and pore size were increased by increase of nanoparticle concentration, except for 1%wt. Use of PANI-co- MWCNT nanoparticles in the membrane matrix caused a decrease of membrane contact angle from 63.43 to 46.76o. Salt rejection and water flux were improved initially by increase of nanoparticle concentration up to 0.1%wt and then decreased by more additive concentration. In addition, the membranes tensile strength was reduced by increase of PANI-co-MWCNTs composite nanoparticle concentration. 3D surface images showed a smoother surface for mixed matrix membrane filled with 0.1wt% PANI-co-MWCNTs. Modified membrane containing 0.1wt% composite nanoparticles showed better performance compared to others.

  10. Preparation of mixed matrix PES-based nanofiltration membrane filled with PANI-co-MWCNT composite nanoparticles

    International Nuclear Information System (INIS)

    Bagheripour, Ehsan; Moghadassi, Abdolreza; Hosseini, Sayed Mohsen

    2016-01-01

    Mixed matrix polyethersulfone/PANI-co-MWCNTs composite nanoparticle nanofiltration membrane was prepared by casting solution technique. Polyvinylpyrrolidone was also used as membrane pore former in membrane fabrication. The effect of polyaniline-co-multi walled carbon nanotubes composite nanoparticle concentration in the casting solution on membrane structure and performance was investigated. Scanning optical microscopy and scanning electron microscopy, FTIR analysis, porosity, mean pore size, contact angle, water content, NaCl/Na2SO4 rejection, water flux, tensile strength measurements and 3D surface image were also carried out in membrane characterization. SOM images showed nanoparticle agglomeration at high additive loading ratio. SEM images showed the membrane sub-layer porosity and thickness were changed by use of nanoparticles in membrane matrix. The membrane water content, porosity and pore size were increased by increase of nanoparticle concentration, except for 1%wt. Use of PANI-co- MWCNT nanoparticles in the membrane matrix caused a decrease of membrane contact angle from 63.43 to 46.76o. Salt rejection and water flux were improved initially by increase of nanoparticle concentration up to 0.1%wt and then decreased by more additive concentration. In addition, the membranes tensile strength was reduced by increase of PANI-co-MWCNTs composite nanoparticle concentration. 3D surface images showed a smoother surface for mixed matrix membrane filled with 0.1wt% PANI-co-MWCNTs. Modified membrane containing 0.1wt% composite nanoparticles showed better performance compared to others.

  11. Mixed matrix membranes prepared from high impact polystyrene with dispersed TiO2 nanoparticles for gas separation

    Directory of Open Access Journals (Sweden)

    P. Safaei

    2016-01-01

    Full Text Available The current study presents synthesis and characterization of high impact polystyrene - TiO2 nanoparticles mixed matrix membranes for separation of carbon dioxide from nitrogen. The solution-casting method was used for preparation of membranes. The nano mixed matrix membranes were characterized using scanning electron microscopy to ensure the suitable dispersion of nano particles in high impact polystyrene matrix. The effect of TiO2 nanoparticles loading on membrane performance was investigated. The separation performance of synthesized membranes was investigated in separation of CO2 from CO2/N2 mixture. Effect of feed pressure and TiO2 content on separation of CO2 was studied. The results revealed that increase of feed pressure decreases flux of gases through the mixed matrix membrane. The results also confirmed that the best separation performance can be obtained at TiO2 nanoparticles loading of 7 wt.%.

  12. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite membranes. We report here the first mixed matrix composite membrane made of commercially available poly (amide-b-ethylene oxide) (Pebax®1657, Arkema) mixed with the nano-sized zeolitic imidazole framework ZIF-7. This hybrid material has been successfully deposited as a thin layer (less than 1μm) on a porous polyacrylonitrile (PAN) support. An intermediate gutter layer of PTMSP was applied to serve as a flat and smooth surface for coating to avoid polymer penetration into the porous support. Key features of this work are the preparation and use of ultra-small ZIF-7 nano-particles (around 30-35nm) and the membrane processability of Pebax®1657. SEM pictures show that excellent adhesion and almost ideal morphology between the two phases has been obtained simply by mixing the as-synthesized ZIF-7 suspension into the Pebax®1657 dope, and no voids or clusters can be observed. The performance of the composite membrane is characterized by single gas permeation measurement of CO2, N2 and CH4. Both, permeability (PCO2 up to 145barrer) and gas selectivity (CO2/N2 up to 97 and CO2/CH4 up to 30) can be increased at low ZIF- loading. The CO2/CH4 selectivity can be further increased to 44 with the filler loading of 34wt%, but the permeability is reduced compared to the pure Pebax®1657 membrane. Polymer chain rigidification at high filler loading is supposed to be a reason for the reduced permeability. The composite membranes prepared in this work show better performance in terms of permeance and selectivity when compared with asymmetric mixed matrix membranes described in the recent literature. Overall, the ZIF 7/Pebax mixed matrix membranes show a high performance for CO2 separation from methane and other gas streams. They are easy to

  13. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying

    2012-05-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  14. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying; Johnson, J.R.; Karvan, Oğuz; Sholl, David S.; Koros, W.J.

    2012-01-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  15. Mixed matrix membranes with fast and selective transport pathways for efficient CO2 separation

    Science.gov (United States)

    Hou, Jinpeng; Li, Xueqin; Guo, Ruili; Zhang, Jianshu; Wang, Zhongming

    2018-03-01

    To improve CO2 separation performance, porous carbon nanosheets (PCNs) were used as a filler into a Pebax MH 1657 (Pebax) matrix, fabricating mixed matrix membranes (MMMs). The PCNs exhibited a preferential horizontal orientation within the Pebax matrix because of the extremely large 2D plane and nanoscale thickness of the matrix. Therefore, the micropores of the PCNs provided fast CO2 transport pathways, which led to increased CO2 permeability. The reduced pore size of the PCNs was a consequence of the overlapping of PCNs and the polymer chains penetrating into the pores of the PCNs. The reduction in the pore size of the PCNs improved the CO2/gas selectivity. As a result, the CO2 permeability and CO2/CH4 selectivity of the Pebax membrane with 10 wt% PCNs-loading (Pebax-PCNs-10) were 520 barrer and 51, respectively, for CO2/CH4 mixed-gas. The CO2 permeability and CO2/N2 selectivity of the Pebax-PCNs-10 membrane were 614 barrer and 61, respectively, for CO2/N2 mixed-gas.

  16. Perlecan and basement membrane-chondroitin sulfate proteoglycan (bamacan) are two basement membrane chondroitin/dermatan sulfate proteoglycans in the Engelbreth-Holm-Swarm tumor matrix

    DEFF Research Database (Denmark)

    Couchman, J R; Kapoor, R; Sthanam, M

    1996-01-01

    heparan sulfate proteoglycan, widespread in many basement membranes and connective tissues. We now identify two distinct proteoglycan species from this tumor source, which are substituted with galactosaminoglycans and which show basement membrane localization by immunohistochemistry. One species......The presence of proteoglycans bearing galactosaminoglycan chains has been reported, but none has been identified previously in the matrix of the Engelbreth-Holm-Swarm tumor, which is a source of several basement membrane components. This tumor matrix contains perlecan, a large, low buoyant density......-CSPG are distinct in core protein structure. Both are, however, basement membrane components, although there are tissue-specific differences in their distribution....

  17. Double layer mixed matrix membrane adsorbers improving capacity and safety hemodialysis

    Science.gov (United States)

    Saiful; Borneman, Z.; Wessling, M.

    2018-05-01

    Double layer mixed matrix membranes adsorbers have been developed for blood toxin removal by embedding activated carbon into cellulose acetate macroporous membranes. The membranes are prepared by phase inversion method via water vapor induced phase separation followed by an immersion precipitation step. Double layer MMM consisting of an active support and a separating layer. The active support layer consists of activated carbon particles embedded in macroporous cellulose acetate; the separating layer consists of particle free cellulose acetate. The double layer membrane possess an open and interconnected macroporous structure with a high loading of activated carbon available for blood toxins removal. The MMM AC has a swelling degree of 6.5 %, porosity of 53 % and clean water flux of 800 Lm-2h-1bar-1. The prepared membranes show a high dynamic Creatinine (Crt) removal during hemodilysis process. The Crt removal by adsorption contributes to amore than 83 % of the total removal. The double layer adsorptive membrane proves hemodialysis membrane can integrated with adsorption, in which blood toxins are removed in one step.

  18. Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes.

    Science.gov (United States)

    Hussain, Abid; Farrukh, Sarah; Hussain, Arshad; Ayoub, Muhammad

    2017-12-05

    Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO 2 molecules and augment CO 2 /CH 4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO 2 /CH 4 selectivity. In single gas experiments, CO 2 /CH 4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO 2 /CH 4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes.

  19. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2018-01-01

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

  20. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina

    2018-05-17

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

  1. Type 1 diabetes

    Science.gov (United States)

    Insulin-dependent diabetes; Juvenile onset diabetes; Diabetes - type 1; High blood sugar - type 1 diabetes ... Type 1 diabetes can occur at any age. It is most often diagnosed in children, adolescents, or young adults. Insulin is ...

  2. Prepare and characterization of nanocomposite - mixed matrix membranes based on polycarbonate

    International Nuclear Information System (INIS)

    Paranhos, Caio M.; Pessan, Luiz A.; Gomes, Ana C. de O.

    2009-01-01

    Mixed matrix membranes based on polycarbonate with different content of sepiolite were prepared by casting. The obtained membranes were characterized by wide-angle X-ray diffraction, thermal analysis, optical transparency and permeation to oxygen. The presence of sepiolite leads to the formation of a polymer-clay interface. The presence of the interface causes the increase in O 2 permeation. Increasing content of sepiolite results in aggregates of sepiolite, which forms preferential channels to the O 2 molecules. This fact is directly related to the strong increasing observed in O 2 permeability. (author)

  3. Synthesis and localization of two sulphated glycoproteins associated with basement membranes and the extracellular matrix

    DEFF Research Database (Denmark)

    Hogan, B L; Taylor, A; Kurkinen, M

    1982-01-01

    's membrane by mouse embryo parietal endoderm cells (Hogan, B. L.M., A. Taylor, and A.R. Cooper, 1982, Dev. Biol., 90:210-214). Both the Mr 180,000 and 150,000 sgps are deposited in the detergent-insoluble matrix of cultured cells, but they do not apparently undergo any disulphide-dependent intermolecular...... interactions and are not precursors or products of each other. They contain asparagine-linked oligosaccharides, but these are not the exclusive sites of sulphate labeling. Antiserum raised against the Mr 150,000 sgp C of Reichert's membranes has been used in an immunohistochemical analysis of rat skin...

  4. Interfacial Design of Mixed Matrix Membranes for Improved Gas Separation Performance.

    Science.gov (United States)

    Wang, Zhenggong; Wang, Dong; Zhang, Shenxiang; Hu, Liang; Jin, Jian

    2016-05-01

    High-performance metal-organic framework (MOF)/polyimide (PI) mixed matrix membranes (MMMs) are fabricated by a facile strategy by designing the MOF/PI matrix interface via poly dopamine coating. The overall separation performance of the designed MMMs surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H2 /N2 gas pairs and approaches the 2008 upper bound for the O2 /N2 gas pair. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Plasma membrane factor XIIIA transglutaminase activity regulates osteoblast matrix secretion and deposition by affecting microtubule dynamics.

    Directory of Open Access Journals (Sweden)

    Hadil F Al-Jallad

    2011-01-01

    Full Text Available Transglutaminase activity, arising potentially from transglutaminase 2 (TG2 and Factor XIIIA (FXIIIA, has been linked to osteoblast differentiation where it is required for type I collagen and fibronectin matrix deposition. In this study we have used an irreversible TG-inhibitor to 'block -and-track' enzyme(s targeted during osteoblast differentiation. We show that the irreversible TG-inhibitor is highly potent in inhibiting osteoblast differentiation and mineralization and reduces secretion of both fibronectin and type I collagen and their release from the cell surface. Tracking of the dansyl probe by Western blotting and immunofluorescence microscopy demonstrated that the inhibitor targets plasma membrane-associated FXIIIA. TG2 appears not to contribute to crosslinking activity on the osteoblast surface. Inhibition of FXIIIA with NC9 resulted in defective secretory vesicle delivery to the plasma membrane which was attributable to a disorganized microtubule network and decreased microtubule association with the plasma membrane. NC9 inhibition of FXIIIA resulted in destabilization of microtubules as assessed by cellular Glu-tubulin levels. Furthermore, NC9 blocked modification of Glu-tubulin into 150 kDa high-molecular weight Glu-tubulin form which was specifically localized to the plasma membrane. FXIIIA enzyme and its crosslinking activity were colocalized with plasma membrane-associated tubulin, and thus, it appears that FXIIIA crosslinking activity is directed towards stabilizing the interaction of microtubules with the plasma membrane. Our work provides the first mechanistic cues as to how transglutaminase activity could affect protein secretion and matrix deposition in osteoblasts and suggests a novel function for plasma membrane FXIIIA in microtubule dynamics.

  6. Proteomics of Fuchs' Endothelial Corneal Dystrophy support that the extracellular matrix of Descemet's membrane is disordered

    DEFF Research Database (Denmark)

    Poulsen, Ebbe Toftgaard; Dyrlund, Thomas F; Runager, Kasper

    2014-01-01

    Fuchs' endothelial corneal dystrophy (FECD) is a major corneal disorder affecting the innermost part of the cornea, leading to visual impairment. As the morphological changes in FECD are mainly observed in the extracellular matrix of the Descemet's membrane/endothelial layer we determined...... that the morphological changes observed in FECD is caused in part by an aberrant assembly of the extracellular matrix within the Descemet's membrane/endothelial layer......., respectively, of which 10 were significantly regulated. The results indicated that the level of type VIII collagen was unaltered even though the protein previously has been implicated in familial early onset forms of the disease. Using the second relative quantitation method iTRAQ we identified 22...

  7. EXPERIMENTAL DESIGN AND RESPONSE SURFACE MODELING OF PI/PES-ZEOLITE 4A MIXED MATRIX MEMBRANE FOR CO2 SEPARATION

    Directory of Open Access Journals (Sweden)

    T. D. KUSWORO

    2015-09-01

    Full Text Available This paper investigates the effect of preparation of polyimide/polyethersulfone (PI/PES blending-zeolite mixed matrix membrane through the manipulation of membrane production variables such as polymer concentration, blending composition and zeolite loading. Combination of central composite design and response surface methodology were applied to determine the main effect and interaction effects of these variables on membrane separation performance. The quadratic models between each response and the independent parameters were developed and the response surface models were tested with analysis of variance (ANOVA. In this study, PI/ (PES–zeolite 4A mixed matrix membranes were casted using dry/wet phase inversion technique. The separation performance of mixed matrix membrane had been tested using pure gases such as CO2 and CH4. The results showed that zeolite loading was the most significant variable that influenced the CO2/CH4 selectivity among three variables and the experimental results were in good agreement with those predicted by the proposed regression models. The gas separation performance of the membrane was relatively higher as compare to polymeric membrane. Therefore, combination of central composite design and response surface methodology can be used to prepare optimal condition for mixed matrix membrane fabrication. The incorporation of 20 wt% zeolite 4A into 25 wt% of PI/PES matrix had resulted in a high separation performance of membrane material.

  8. Human immunodeficiency virus type 1 KK26-27 matrix mutants display impaired infectivity, circularization and integration but not nuclear import

    International Nuclear Information System (INIS)

    Mannioui, Abdelkrim; Nelson, Elisabeth; Schiffer, Cecile

    2005-01-01

    We analyzed the role of human immunodeficiency virus (HIV)-1 matrix protein (MA) during the virus replication afferent phase. Single-round infection of H9 T lymphocytes showed that the combined mutation of MA Lys residues 26-27 in MA reported nuclear localization signal (NLS)-1 [Haffar, O.K., Popov, S., Dubrovsky, L., Agostini, I., Tang, H., Pushkarsky, T., Nadler, S.G., Bukrinsky, M., 2000. Two nuclear localization signals in the HIV-1 matrix protein regulate nuclear import of the HIV-1 pre-integration complex. J. Mol. Biol. 299 (2): 359-368] impaired infectivity, abrogated 2-LTR-circle formation and significantly reduced integration. However, the mutation did not affect viral DNA docking to chromatin in either interphasic or mitotic cells, indicating that MA N-terminal basic domain should not represent a major determinant of HIV-1 nuclear import in T lymphocytes. These data point to a previously unreported role of MA in the late, post-chromatin-binding, afferent phase of HIV-1 replication cycle

  9. [Application of the xenogenic acellular dermal matrix membrane application used in the postoperative tissue shortage repair].

    Science.gov (United States)

    Bai, Yanxia; Yan, Liying; Zhang, Shaoqiang; Shao, Yuan; Yao, Xiaobao; Li, Honghui; Zhao, Ruimin; Zhao, Qian; Zhang, Pengfei; Yang, Qi

    2014-09-01

    To observe the short-term and long-term curative effect of the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer) application used in the 82 cases postoperative tissue shortage repair that after the head neck carcinoma resection. To held the 82 cases head neck carcinoma postoperative mucosa shortage repaired after resection by the xenogenic acellular dermal matrix membrane (or joint muscle flap transfer), 65 cases mucosa shortage wound be directly covered by the repair membrane and the other 17 cases mucosa shortage wound be repaired by the tranfered muscle tissue flap with the repair membrane covered; 53 cases underwent additional postoperative radiotherapy between 2-4 weeks and follow-up in 1, 3, 6, 12, 18, 24, 30, 36, 48, 60 months and observed the operation site repair process through the electronic laryngoscope, observed the patients respiration, swallow, phonation function. Seventy-seven cases patients operation incision reached I phase healing standard, another 5 cases patients operation incision reached II phase healing standard because of the wound infection and fully-recovered through the local wound drainage,dressing process. All the patients tracheal cannula,the stomach tube be extubated successfully and without the local cicatricial constriction occurred. Seventy-eight cases follow up period reached 1 year including 53 cases who underwent postoperative radiotherapy, 49 cases follow up period reached 3 years including 32 cases who underwent postoperative radiotherapy, 14 cases follow up period reached 5 years including 12 cases who underwent postoperative radiotherapy. The patients with static local lesions discovered no reaction such as exclusion, allergy. The application of xenogenic acellular dermal matrix membrane (or joint muscle flap transfer used in in the postoperative tissue shortage repair that after the head neck carcinoma resection have several advantage such as comparatively easily implementation, operation safety

  10. PES-Kaolin Mixed Matrix Membranes for Arsenic Removal from Water.

    Science.gov (United States)

    Marino, Tiziana; Russo, Francesca; Rezzouk, Lina; Bouzid, Abderrazak; Figoli, Alberto

    2017-09-30

    The aim of this work was the fabrication and the characterization of mixed matrix membranes (MMMs) for arsenic (As) removal from water. Membrane separation was combined with an adsorption process by incorporating the kaolin (KT2) Algerian natural clay in polymeric membranes. The effects of casting solution composition was explored using different amounts of polyethersufone (PES) as a polymer, polyvinyl-pyrrolidone (PVP K17) and polyethylene glycol (PEG 200) as pore former agents, N -methyl pyrrolidone (NMP) as a solvent, and kaolin. Membranes were prepared by coupling Non-solvent Induced Phase Separation and Vapour Induced Phase Separation (NIPS and VIPS, respectively). The influence of the exposure time to controlled humid air and temperature was also investigated. The MMMs obtained were characterized in terms of morphology, pore size, porosity, thickness, contact angle and pure water permeability. Adsorption membrane-based tests were carried out in order to assess the applicability of the membranes produced for As removal from contaminated water. Among the investigated kaolin concentrations (ranging from 0 wt % to 5 wt %), a content of 1.25 wt % led to the MMM with the most promising performance.

  11. Mixed Matrix Carbon Molecular Sieve and Alumina (CMS-Al2O3) Membranes.

    Science.gov (United States)

    Song, Yingjun; Wang, David K; Birkett, Greg; Martens, Wayde; Duke, Mikel C; Smart, Simon; Diniz da Costa, João C

    2016-07-29

    This work shows mixed matrix inorganic membranes prepared by the vacuum-assisted impregnation method, where phenolic resin precursors filled the pore of α-alumina substrates. Upon carbonisation, the phenolic resin decomposed into several fragments derived from the backbone of the resin matrix. The final stages of decomposition (>650 °C) led to a formation of carbon molecular sieve (CMS) structures, reaching the lowest average pore sizes of ~5 Å at carbonisation temperatures of 700 °C. The combination of vacuum-assisted impregnation and carbonisation led to the formation of mixed matrix of CMS and α-alumina particles (CMS-Al2O3) in a single membrane. These membranes were tested for pervaporative desalination and gave very high water fluxes of up to 25 kg m(-2) h(-1) for seawater (NaCl 3.5 wt%) at 75 °C. Salt rejection was also very high varying between 93-99% depending on temperature and feed salt concentration. Interestingly, the water fluxes remained almost constant and were not affected as feed salt concentration increased from 0.3, 1 and 3.5 wt%.

  12. Mutations in matrix and SP1 repair the packaging specificity of a Human Immunodeficiency Virus Type 1 mutant by reducing the association of Gag with spliced viral RNA

    Directory of Open Access Journals (Sweden)

    Ristic Natalia

    2010-09-01

    Full Text Available Abstract Background The viral genome of HIV-1 contains several secondary structures that are important for regulating viral replication. The stem-loop 1 (SL1 sequence in the 5' untranslated region directs HIV-1 genomic RNA dimerization and packaging into the virion. Without SL1, HIV-1 cannot replicate in human T cell lines. The replication restriction phenotype in the SL1 deletion mutant appears to be multifactorial, with defects in viral RNA dimerization and packaging in producer cells as well as in reverse transcription of the viral RNA in infected cells. In this study, we sought to characterize SL1 mutant replication restrictions and provide insights into the underlying mechanisms of compensation in revertants. Results HIV-1 lacking SL1 (NLΔSL1 did not replicate in PM-1 cells until two independent non-synonymous mutations emerged: G913A in the matrix domain (E42K on day 18 postinfection and C1907T in the SP1 domain (P10L on day 11 postinfection. NLΔSL1 revertants carrying either compensatory mutation showed enhanced infectivity in PM-1 cells. The SL1 revertants produced significantly more infectious particles per nanogram of p24 than did NLΔSL1. The SL1 deletion mutant packaged less HIV-1 genomic RNA and more cellular RNA, particularly signal recognition particle RNA, in the virion than the wild-type. NLΔSL1 also packaged 3- to 4-fold more spliced HIV mRNA into the virion, potentially interfering with infectious virus production. In contrast, both revertants encapsidated 2.5- to 5-fold less of these HIV-1 mRNA species. Quantitative RT-PCR analysis of RNA cross-linked with Gag in formaldehyde-fixed cells demonstrated that the compensatory mutations reduced the association between Gag and spliced HIV-1 RNA, thereby effectively preventing these RNAs from being packaged into the virion. The reduction of spliced viral RNA in the virion may have a major role in facilitating infectious virus production, thus restoring the infectivity of NLΔSL1

  13. Effects of ZnO Nanoparticle on the Gas Separation Performance of Polyurethane Mixed Matrix Membrane.

    Science.gov (United States)

    Soltani, Banafsheh; Asghari, Morteza

    2017-08-11

    Polyurethane (PU)-ZnO mixed matrix membranes (MMM) were fabricated and characterized for gas separation. A thermogravimetric analysis (TGA), a scanning electron microscope (SEM) test and an atomic-force microscopy (AFM) revealed that the physical properties and thermal stability of the membranes were improved through filler loading. Hydrogen Bonding Index, obtained from the Fourier transform infrared spectroscopy (FTIR), demonstrate that the degree of phase separation in PU-ZnO 0.5 wt % MMM was more than the neat PU, while in PU-ZnO 1.0 wt % MMM, the phase mixing had increased. Compared to the neat membrane, the CO₂ permeability of the MMMs increased by 31% for PU-ZnO 0.5 wt % MMM and decreased by 34% for 1.0 wt % ZnO MMM. The CO₂/CH₄ and CO₂/N₂ selectivities of PU-ZnO 0.5 wt % were 18.75 and 64.75, respectively.

  14. Balance between Apical Membrane Growth and Luminal Matrix Resistance Determines Epithelial Tubule Shape

    Directory of Open Access Journals (Sweden)

    Bo Dong

    2014-05-01

    Full Text Available The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape.

  15. Balance between apical membrane growth and luminal matrix resistance determines epithelial tubule shape.

    Science.gov (United States)

    Dong, Bo; Hannezo, Edouard; Hayashi, Shigeo

    2014-05-22

    The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM) of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Novel ZIF-300 Mixed-Matrix Membranes for Efficient CO2 Capture.

    Science.gov (United States)

    Yuan, Jianwei; Zhu, Haipeng; Sun, Jiajia; Mao, Yangyang; Liu, Gongping; Jin, Wanqin

    2017-11-08

    Because of the high separation performance and easy preparation, mixed-matrix membranes (MMMs) consisting of metal-organic frameworks have received much attention. In this article, we report a novel ZIF-300/PEBA MMM consisting of zeolite imidazolate framework (ZIF-300) crystals and polyether block amide (PEBA) matrix. The ZIF-300 crystal size was effectively reduced by optimizing the hydrothermal reaction condition from ∼15 to ∼1 μm. The morphology and physicochemical and sorption properties of the synthesized ZIF-300 crystals and as-prepared ZIF-300/PEBA MMMs were systematically studied. The results showed that ZIF-300 crystals with a size of ∼1 μm maintained excellent preferential CO 2 sorption over N 2 without degradation of the crystal structure in the MMMs. As a result, uniformly incorporated ZIF-300 crystals highly enhanced both the CO 2 permeability and the CO 2 /N 2 selectivity of pure PEBA membrane. The optimized ZIF-300-PEBA MMMs with a ZIF-300 loading of 30 wt % exhibited a high and stable CO 2 permeability of 83 Barrer and CO 2 /N 2 selectivity of 84, which are 59.2% and 53.5% higher than pure PEBA membrane, respectively. The obtained performance surpassed the upper bound of state-of-the-art membranes for CO 2 /N 2 separation. This work demonstrated that the proposed ZIF-300/PEBA MMM could be a potential candidate for an efficient CO 2 capture process.

  17. Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

    Science.gov (United States)

    Khan, Muntazim Munir; Filiz, Volkan; Bengtson, Gisela; Shishatskiy, Sergey; Rahman, Mushfequr; Abetz, Volker

    2012-09-06

    The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

  18. CO2/CH4 Separation by a Mixed Matrix Membrane of Polymethylpentyne/MIL-53 Particles

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2014-10-01

    Full Text Available The effect of Materials Institute Lavoisier-53 (MIL-53 particles on gas transport properties of polymethylpentyne (PMP was investigated. MIL-53 was added to the polymer matrix with different loadings of 10, 20 and 30 wt%. The properties of MIL-53 and prepared membranes were analyzed through FTIR, SEM and TGA methods. The adsorption of CO2 and CH4 was conducted and analyzed accurately through Langmuir equation to investigate the gas transport properties of membranes. The results from TGA showed that degradation temperature (Td increases significantly with increasing MIL-53 loading. SEM images demonstrated that MIL-53 particles dispersed well in polymer matrix with no considerable agglomeration and no non-selective void formation at polymer/filler interface. In addition, CO2 and CH4 permeability measurement along with calculation of CO2/CH4 selectivity were performed. The results showed that the permeability of gases (especially for CO2 increased significantly by increasing the MIL-53 loading. Additionally, CO2/CH4 selectivity showed an increasing trend with increasing the MIL-53 weight percent. Unlike CH4, the CO2 solubility coefficient increased with increasing the MIL-53 loading because of high free volume of membrane and selective adsorption of CO2 with MIL-53. Despite CO2 solubility enhancement its diffusivity coefficient remained more or less unchanged. The enhancement in CH4 permeability has been mainly attributed to its slight incremental diffusivity due to the membrane's increasingly higher free volume. Finally, a comparison between membranes performance and CO2/CH4 Robeson upper bound showed that, the performance of membranes improved due to the presence of MIL-53 which was very close to the Robeson bound.

  19. Calculating the permeability coefficients of mixed matrix membranes of polydimethylsiloxane and silicalite crystals to various ethanol-water solutions using molecular simulations.

    Science.gov (United States)

    The permeability coefficients of mixed matrix membranes of polydimethylsiloxane (PDMS) and silicalite crystal are taken as the sum of the permeability coefficients of membrane components each weighted by their associated mass fraction. The permeability coefficient of a membrane c...

  20. Correlations of the glycemic variability with oxidative stress and erythrocytes membrane stability in patients with type 1 diabetes under intensive treatment.

    Science.gov (United States)

    Rodrigues, Ricardo; Alves de Medeiros, Luciana; Moreira Cunha, Lucas; da Silva Garrote-Filho, Mario; Bernardino Neto, Morun; Tannus Jorge, Paulo; Santos Resende, Elmiro; Penha-Silva, Nilson

    2018-02-07

    This study aimed to evaluate the correlations of glycemic variability with erythrocyte membrane stability parameters and oxidative stress markers in patients with DM1 under intensive treatment. 90 patients with DM1 and under intensive treatment of the disease were evaluated in relation to anthropometric indices, records of glycemic averages and parameters of glycemic variability, biochemical dosages (glucose, uric acid, lipidogram, glycated hemoglobin, microalbuminuria, creatinine and iron) reticulocyte count, erythrocyte membrane stability parameters and oxidative stress markers (thiobarbituric acid reactive substances, TBARS, and glutathione reductase, GR). Indicators of glycemic variability in the short and long term showed correlations with parameters of membrane stability and markers of oxidative stress (GR). In addition, the comparison of these same parameters between the subgroups consisting of quartiles of GV or glycemic control also showed significant differences. In the DM1 patients studied here, glycemic variability showed correlations with oxidative stress and erythrocyte membrane stability variables. This corroborates the hypothesis that glycemic fluctuations interfere with lipid peroxidation and cell membrane behavior, emphasizing its participation in mechanisms related to the development of chronic complications of diabetes. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. HIV-1 matrix dependent membrane targeting is regulated by Gag mRNA trafficking.

    Directory of Open Access Journals (Sweden)

    Jing Jin

    Full Text Available Retroviral Gag polyproteins are necessary and sufficient for virus budding. Productive HIV-1 Gag assembly takes place at the plasma membrane. However, little is known about the mechanisms by which thousands of Gag molecules are targeted to the plasma membrane. Using a bimolecular fluorescence complementation (BiFC assay, we recently reported that the cellular sites and efficiency of HIV-1 Gag assembly depend on the precise pathway of Gag mRNA export from the nucleus, known to be mediated by Rev. Here we describe an assembly deficiency in human cells for HIV Gag whose expression depends on hepatitis B virus (HBV post-transcriptional regulatory element (PRE mediated-mRNA nuclear export. PRE-dependent HIV Gag expressed well in human cells, but assembled with slower kinetics, accumulated intracellularly, and failed to associate with a lipid raft compartment where the wild-type Rev-dependent HIV-1 Gag efficiently assembles. Surprisingly, assembly and budding of PRE-dependent HIV Gag in human cells could be rescued in trans by co-expression of Rev-dependent Gag that provides correct membrane targeting signals, or in cis by replacing HIV matrix (MA with other membrane targeting domains. Taken together, our results demonstrate deficient membrane targeting of PRE-dependent HIV-1 Gag and suggest that HIV MA function is regulated by the trafficking pathway of the encoding mRNA.

  2. Crystal structure of an orthomyxovirus matrix protein reveals mechanisms for self-polymerization and membrane association.

    Science.gov (United States)

    Zhang, Wenting; Zheng, Wenjie; Toh, Yukimatsu; Betancourt-Solis, Miguel A; Tu, Jiagang; Fan, Yanlin; Vakharia, Vikram N; Liu, Jun; McNew, James A; Jin, Meilin; Tao, Yizhi J

    2017-08-08

    Many enveloped viruses encode a matrix protein. In the influenza A virus, the matrix protein M1 polymerizes into a rigid protein layer underneath the viral envelope to help enforce the shape and structural integrity of intact viruses. The influenza virus M1 is also known to mediate virus budding as well as the nuclear export of the viral nucleocapsids and their subsequent packaging into nascent viral particles. Despite extensive studies on the influenza A virus M1 (FLUA-M1), only crystal structures of its N-terminal domain are available. Here we report the crystal structure of the full-length M1 from another orthomyxovirus that infects fish, the infectious salmon anemia virus (ISAV). The structure of ISAV-M1 assumes the shape of an elbow, with its N domain closely resembling that of the FLUA-M1. The C domain, which is connected to the N domain through a flexible linker, is made of four α-helices packed as a tight bundle. In the crystal, ISAV-M1 monomers form infinite 2D arrays with a network of interactions involving both the N and C domains. Results from liposome flotation assays indicated that ISAV-M1 binds membrane via electrostatic interactions that are primarily mediated by a positively charged surface loop from the N domain. Cryoelectron tomography reconstruction of intact ISA virions identified a matrix protein layer adjacent to the inner leaflet of the viral membrane. The physical dimensions of the virion-associated matrix layer are consistent with the 2D ISAV-M1 crystal lattice, suggesting that the crystal lattice is a valid model for studying M1-M1, M1-membrane, and M1-RNP interactions in the virion.

  3. Preparation and characterization of polysulfone/zeolite mixed matrix membranes for removal of low-concentration ammonia from aquaculture wastewater.

    Science.gov (United States)

    Moradihamedani, Pourya; Abdullah, Abdul Halim

    2018-01-01

    Removal of low-concentration ammonia (1-10 ppm) from aquaculture wastewater was investigated via polysulfone (PSf)/zeolite mixed matrix membrane. PSf/zeolite mixed matrix membranes with different weight ratios (90/10, 80/20, 70/30 and 60/40 wt.%) were prepared and characterized. Results indicate that PSf/zeolite (80/20) was the most efficient membrane for removal of low-concentration ammonia. The ammonia elimination by PSf/zeolite (80/20) from aqueous solution for 10, 7, 5, 3 and 1 ppm of ammonia was 100%, 99%, 98.8%, 96% and 95% respectively. The recorded results revealed that pure water flux declined in higher loading of zeolite in the membrane matrix due to surface pore blockage caused by zeolite particles. On the other hand, ammonia elimination from water was decreased in higher contents of zeolite because of formation of cavities and macrovoids in the membrane substructure.

  4. Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Raka; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

    2014-01-30

    Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute.

  5. Membrane-type matrix metalloproteases as diverse effectors of cancer progression.

    Science.gov (United States)

    Turunen, S Pauliina; Tatti-Bugaeva, Olga; Lehti, Kaisa

    2017-11-01

    Membrane-type matrix metalloproteases (MT-MMP) are pivotal regulators of cell invasion, growth and survival. Tethered to the cell membranes by a transmembrane domain or GPI-anchor, the six MT-MMPs can exert these functions via cell surface-associated extracellular matrix degradation or proteolytic protein processing, including shedding or release of signaling receptors, adhesion molecules, growth factors and other pericellular proteins. By interactions with signaling scaffold or cytoskeleton, the C-terminal cytoplasmic tail of the transmembrane MT-MMPs further extends their functionality to signaling or structural relay. MT-MMPs are differentially expressed in cancer. The most extensively studied MMP14/MT1-MMP is induced in various cancers along malignant transformation via pathways activated by mutations in tumor suppressors or proto-oncogenes and changes in tumor microenvironment including cellular heterogeneity, extracellular matrix composition, tissue oxygenation, and inflammation. Classically such induction involves transcriptional programs related to epithelial-to-mesenchymal transition. Besides inhibition by endogenous tissue inhibitors, MT-MMP activities are spatially and timely regulated at multiple levels by microtubular vesicular trafficking, dimerization/oligomerization, other interactions and localization in the actin-based invadosomes, in both tumor and the stroma. The functions of MT-MMPs are multifaceted within reciprocal cellular responses in the evolving tumor microenvironment, which poses the importance of these proteases beyond the central function as matrix scissors, and necessitates us to rethink MT-MMPs as dynamic signaling proteases of cancer. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. [Evaluation of the Peusner's coefficients matrix for polymeric membrane and ternary non-electrolyte solutions].

    Science.gov (United States)

    Jasik-Slęzak, Jolanta; Slęzak-Prochazka, Izabella; Slęzak, Andrzej

    2014-01-01

    A system of network forms of Kedem-Katchalsky (K-K) equations for ternary non-electrolyte solutions is made of eight matrix equations containing Peusner's coefficients R(ij), L(ij), H(ij), W(ij), K(ij), N(ij), S(ij) or P(ij) (i, j ∈ {1, 2, 3}). The equations are the result of symmetric or hybrid transformation of the classic form of K-K equations by the use of methods of Peusner's network thermodynamics (PNT). Calculating concentration dependences of the determinant of Peusner's coefficients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) and P(ij) (i, j ∈ {1, 2, 3}). The material used in the experiment was a hemodialysis Nephrophan membrane with specified transport properties (L(p), σ, Ω) in aqueous glucose and ethanol solution. The method involved equations for determinants of the matrixes coefficients R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}). The objective of calculations were dependences of determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) within the conditions of solution homogeneity upon an average concentration of one component of solution in the membrane (C1) with a determined value of the second component (C2). The method of calculating the determinants of Peusner's coeffcients matrixes R(ij), L(ij), H(ij), W(ij), S(ij), N(ij), K(ij) or P(ij) (i, j ∈ {1, 2, 3}) is a new tool that may be applicable in studies on membrane transport. Calculations showed that the coefficients are sensitive to concentration and composition of solutions separated by a polymeric membrane.

  7. Fabrication of Functionalized MOFs Incorporated Mixed Matrix Hollow Fiber Membrane for Gas Separation

    Directory of Open Access Journals (Sweden)

    Haitao Zhu

    2017-01-01

    Full Text Available The metal-organic framework (MOFs of MIL-53 was functionalized by aminosilane grafting and then incorporated into Ultem®1000 polymer matrix to fabricate mixed matrix hollow fiber membrane (MMHFM with high separation performance. SEM, XRD, and TGA were performed to characterize the functionalized MIL-53 and prepared MMHFM. The filler particles were embedded in membrane successfully and dispersed well in the polymer matrix. The incorporation of MOFs endowed MMHFM better thermal stability. Moreover, effects of solvent ratio in spinning dope, spinning condition, and testing temperature on gas separation performance of MMHFM were investigated. By optimizing dope composition, air gap distance, and bore fluid composition, MMHFM containing functionalized MIL-53 achieved excellent gas permeance and CO2/N2 selectivity. The CO2 permeance increased from 12.2 GPU for pure Ultem HFM to 30.9 GPU and the ideal CO2/N2 selectivity was enhanced from 25.4 to 34.7 simultaneously. Additionally, gas permeance increased but the selectivity decreased with the temperature increase, which followed the solution-diffusion based transport mechanism.

  8. Diabetes, Type 1

    OpenAIRE

    Riazi, Afsane; Bradley, Clare

    2007-01-01

    This chapter provides an overview of the role of psychological stress in Type 1 diabetes. Studies relating to stress and Type 1 diabetes onset and control, as well as the evidence relating to stress management training in people with Type 1 diabetes are discussed.

  9. Gas transport in metal organic framework–polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, S.; Norder, Ben; Dingemans, Theo J.; Nijmeijer, Dorothea C.

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of

  10. Gas transport in metal organic framework-polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, Salman; Norder, Ben; Dingemans, T.J.; Nijmeijer, Kitty

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of

  11. Annexin A2 Mediates the Localization of Measles Virus Matrix Protein at the Plasma Membrane.

    Science.gov (United States)

    Koga, Ritsuko; Kubota, Marie; Hashiguchi, Takao; Yanagi, Yusuke; Ohno, Shinji

    2018-02-28

    Annexins are a family of structurally related proteins that bind negatively charged membrane phospholipids in a Ca 2+ -dependent manner. Annexin A2 (AnxA2), a member of the family, has been implicated in a variety of cellular functions including the organization of membrane domains, vesicular trafficking and cell-cell adhesion. AnxA2 generally forms the heterotetrameric complex with a small Ca 2+ -binding protein S100A10. Measles virus (MV), a member of the family Paramyxoviridae , is an enveloped virus with a nonsegmented negative strand RNA genome. Knockdown of AnxA2 greatly reduced MV growth in cells, without affecting its entry and viral RNA production. In MV-infected, AnxA2-knockdown cells, the expression level of the matrix (M) protein, but not other viral proteins, was reduced compared with that in control cells, and the distribution of the M protein at the plasma membrane was decreased. The M protein lines the inner surface of the envelope and plays an important role in virus assembly by connecting the nucleocapsid to the envelope proteins. The M protein bound to AnxA2 independently of AnxA2's phosphorylation or its association with S100A10, and was co-localized with AnxA2 within cells. Truncation of the N-terminal 10 amino acid residues, but not the N-terminal 5 residues, compromised the ability of the M protein to interact with AnxA2 and localize at the plasma membrane. These results indicate that AnxA2 mediates the localization of the MV M protein at the plasma membrane by interacting with its N-terminal region (especially residues at positions 6-10), thereby aiding in MV assembly. IMPORTANCE Measles virus (MV) is an important human pathogen, still claiming ∼ 100,000 lives per year despite the presence of effective vaccines, and causes occasional outbreaks even in developed countries. Replication of viruses largely relies on the functions of host cells. Our study revealed that the reduction of the host protein annexin A2 compromises the replication of

  12. Preparation of Ethylene Vinyl Acetate/Zeolite 4A Mixed Matrix Membrane for CO2/N2 Separation

    Directory of Open Access Journals (Sweden)

    Iman Khalilinejad

    2016-07-01

    Full Text Available A great contribution in research activities on carbon dioxide (CO2 separation, as the most important challenge in greenhouse gases control, has been made to develop new polymeric membranes. In this case, mixed matrix membranes (MMMs, comprised of rigid particles dispersed in a continuous polymeric matrix, was proposed as an effective method to improve the separation properties of polymeric membranes. In this research, ethylene vinyl acetate (EVA copolymer and zeolite 4A powders were applied to prepare MMMs using solution casting/solvent evaporation method and CO2/N2 separation performance of the membranes was examined under different feed pressures (3-8 bar and operating temperatures (25-50°C. Morphological and structural characterizations of the membranes were evaluated using scanning electron microscopy (SEM, Fourier transform infrared (FTIR spectroscopy, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, density and solvent-induced swelling measurements. The gas permeability measurements through the constant-volume method showed the permeability of two gases increased in the presence of zeolite 4A nanoparticles in the polymer matrix. Calculation of diffusivity coefficients of gases revealed that improvement in the diffusivity of all gases into membrane matrix was the main reason for permeability enhancement. In addition, the increase in the CO2/N2 ideal selectivity with the presence of zeolite 4A nanoparticles in the polymer matrix was attributed to the increment in CO2/N2 diffusion selectivity. Under optimum condition, with the addition of 10 wt% zeolite 4A nanoparticles into the membrane matrix, the CO2 permeability increased from 20.81 to 35.24 Barrer and its related selectivity increased 20% compared to that of neat EVA membrane. Furthermore, the membrane performances increased upon feed pressure rise, while the selectivity decreased with the increase in temperature.

  13. Effect of Extracellular Matrix Membrane on Bone Formation in a Rabbit Tibial Defect Model

    Directory of Open Access Journals (Sweden)

    Jin Wook Hwang

    2016-01-01

    Full Text Available Absorbable extracellular matrix (ECM membrane has recently been used as a barrier membrane (BM in guided tissue regeneration (GTR and guided bone regeneration (GBR. Absorbable BMs are mostly based on collagen, which is more biocompatible than synthetic materials. However, implanted absorbable BMs can be rapidly degraded by enzymes in vivo. In a previous study, to delay degradation time, collagen fibers were treated with cross-linking agents. These compounds prevented the enzymatic degradation of BMs. However, cross-linked BMs can exhibit delayed tissue integration. In addition, the remaining cross-linker could induce inflammation. Here, we attempted to overcome these problems using a natural ECM membrane. The membrane consisted of freshly harvested porcine pericardium that was stripped from cells and immunoreagents by a cleaning process. Acellular porcine pericardium (APP showed a bilayer structure with a smooth upper surface and a significantly coarser bottom layer. APP is an ECM with a thin layer (0.18–0.35 mm but with excellent mechanical properties. Tensile strength of APP was 14.15±2.24 MPa. In in vivo experiments, APP was transplanted into rabbit tibia. The biocompatible material was retained for up to 3 months without the need for cross-linking. Therefore, we conclude that APP could support osteogenesis as a BM for up to 3 months.

  14. Copolyimide mixed matrix membranes with oriented microporous titanosilicate JDF-L1sheet particles

    OpenAIRE

    Galve, Alejandro; Vispe, Eugenio; Téllez, Carlos; Coronas, Joaquín

    2011-01-01

    JDF-L1 is a microporous titanosilicate exhibiting a layer structure with pore size of about 3 Å. It is consequently an attractive material to separate H2-containing mixtures. This is the reason why JDF-L1, after disaggregation by means of hexadecyltrimethylammonium surfactant, has been combined with a carboxyl group containing copolyimide (6FDA-4MPD/6FDA-DABA 4:1) to produce mixed matrix membranes, which were applied to the separation of H2/CH4 and O2/N2 mixtures. Additionally, due to the she...

  15. Membrane association and localization dynamics of the Ebola virus matrix protein VP40.

    Science.gov (United States)

    Gc, Jeevan B; Gerstman, Bernard S; Chapagain, Prem P

    2017-10-01

    The Ebola virus matrix protein VP40 is a major structural protein that provides the scaffolding for new Ebola virus particles. For this, VP40 is first trafficked to the lower leaflet of the plasma membrane (PM) in its dimeric form. Once associated with the PM, the VP40 dimers undergo structural rearrangements and oligomerize into hexamers and filaments that make up the virus matrix. Therefore, association of the VP40 dimers and their stabilization at the PM is a crucial step in the Ebola life-cycle. To understand the molecular details of the VP40 dimer-PM interactions, we investigated the dimer association with the inner leaflet of the PM using detailed all-atom molecular dynamics (MD) simulations. The formation of the dimer-PM complex is facilitated by the interactions of the VP40 lysine residues and the anionic lipids POPS, POPI, and PIP 2 in the PM. In contrast, the dimer fails to associate with a membrane without POPS, POPI, or PIP 2 lipids. We explored the mechanisms of the association and identified important residues and lipids involved in localization and stabilization of VP40 dimers at the PM. MD simulations elucidate the role of a C-terminal α-helix alignment parallel to the lipid bilayer surface as well as the creation of membrane defects that allow partial insertion of the hydrophobic residue V276 into the membrane to further stabilize the VP40 dimer-PM complex. Understanding the mechanisms of the VP40 dimer-PM association that facilitate oligomerization can be important for potentially targeting the VP40 for small molecules that can interfere with the virus life-cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Phosphatidylserine Lateral Organization Influences the Interaction of Influenza Virus Matrix Protein 1 with Lipid Membranes.

    Science.gov (United States)

    Bobone, Sara; Hilsch, Malte; Storm, Julian; Dunsing, Valentin; Herrmann, Andreas; Chiantia, Salvatore

    2017-06-15

    Influenza A virus matrix protein 1 (M1) is an essential component involved in the structural stability of the virus and in the budding of new virions from infected cells. A deeper understanding of the molecular basis of virion formation and the budding process is required in order to devise new therapeutic approaches. We performed a detailed investigation of the interaction between M1 and phosphatidylserine (PS) (i.e., its main binding target at the plasma membrane [PM]), as well as the distribution of PS itself, both in model membranes and in living cells. To this end, we used a combination of techniques, including Förster resonance energy transfer (FRET), confocal microscopy imaging, raster image correlation spectroscopy, and number and brightness (N&B) analysis. Our results show that PS can cluster in segregated regions in the plane of the lipid bilayer, both in model bilayers constituted of PS and phosphatidylcholine and in living cells. The viral protein M1 interacts specifically with PS-enriched domains, and such interaction in turn affects its oligomerization process. Furthermore, M1 can stabilize PS domains, as observed in model membranes. For living cells, the presence of PS clusters is suggested by N&B experiments monitoring the clustering of the PS sensor lactadherin. Also, colocalization between M1 and a fluorescent PS probe suggest that, in infected cells, the matrix protein can specifically bind to the regions of PM in which PS is clustered. Taken together, our observations provide novel evidence regarding the role of PS-rich domains in tuning M1-lipid and M1-M1 interactions at the PM of infected cells. IMPORTANCE Influenza virus particles assemble at the plasma membranes (PM) of infected cells. This process is orchestrated by the matrix protein M1, which interacts with membrane lipids while binding to the other proteins and genetic material of the virus. Despite its importance, the initial step in virus assembly (i.e., M1-lipid interaction) is still

  17. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-11-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high performance and thermal properties of the fillers. This work explores the fabrication and application of MMMs. We focused on the design and fabrication of nanofillers to impart target functionality to the membrane for water treatment, protective coating and gas separation. This thesis is divided into three sections according to the application including: I- Water Treatment: This part is divided into three chapters, two related to the membrane distillation (MD) and one related to the oil spill. Three different nanofillers have been used: Periodic mesoporous organosilica (PMO), graphene and carbon nanotube (CNT). Those nanofillers were homogeneously incorporated into polyetherimide (PEI) electrospun nanofiber membranes. The doped nanoparticle not only improved the mechanical properties and thermal stability of the pristine fiber but also enhanced the MD and oil spill performance due to the functionality of those nanofillers. II- Protective coating: This part includes two chapters describing the design and the fabrication of a smart antibacterial and anti-corrosion coating. In the first project, we fabricated colloidal lysozyme-templated gold nanoclusters gating antimicrobial-loaded silica nanoparticles (MSN-AuNCs@lys) as nano-fillers in poly(ethylene oxide)/poly(butylene terephthalate) polymer matrix. MSN-AuNCs@lys dispersed homogeneously within the polymer matrix with zero NPs leaching. The system was coated on a common radiographic dental imaging device that is prone to oral bacteria contamination. This coating can successfully sense and inhibit bacterial contamination via a controlled release mechanism that is only triggered by bacteria. In the second project, the coaxial electrospinning approach has been applied to

  18. Role for the disulfide-bonded region of human immunodeficiency virus type 1 gp41 in receptor-triggered activation of membrane fusion function

    International Nuclear Information System (INIS)

    Bellamy-McIntyre, Anna K.; Baer, Severine; Ludlow, Louise; Drummer, Heidi E.; Poumbourios, Pantelis

    2010-01-01

    The conserved disulfide-bonded region (DSR) of the human immunodeficiency virus type 1 (HIV-1) fusion glycoprotein, gp41, mediates association with the receptor-binding glycoprotein, gp120. Interactions between gp120, CD4 and chemokine receptors activate the fusion activity of gp41. The introduction of W596L and W610F mutations to the DSR of HIV-1 QH1549.13 blocked viral entry and hemifusion without affecting gp120-gp41 association. The fusion defect correlated with inhibition of CD4-triggered gp41 pre-hairpin formation, consistent with the DSR mutations having decoupled receptor-induced conformational changes in gp120 from gp41 activation. Our data implicate the DSR in sensing conformational changes in the gp120-gp41 complex that lead to fusion activation.

  19. THE EFFECT OF TYPE ZEOLITE ON THE GAS TRANSPORT PROPERTIES OF POLYIMIDE-BASED MIXED MATRIX MEMBRANES

    Directory of Open Access Journals (Sweden)

    Tutuk Djoko Kusworo

    2012-01-01

    Full Text Available The permeation rates of O2, N2, CO2 and CH4 has been studied for polyimide-polyethersulfone (PI/PES blends-zeolite mixed matrix membranes synthesized in our laboratory. The study investigated the effect of zeolite loading and different zeolite type on the gas separation performance of these mixed matrix membranes. Frequency shifts and absorption intensity changes in the FTIR spectra of the PI/PES blends as compared with those of the pure polymers indicate that there is a mixing of polymer blends at the molecular level. Differential scanning calorimetry measurements of pure and PI/PES blends membranes have showed one unique glass transition temperature that supports the miscible character of the PI/PES mixture. The PI/PES-zeolite 4A mixed matrix membrane with 25 wt % zeolite loading produced the highest O2/N2 and CO2/CH4 selectivity of around 7.45 and 46.05, respectively.

  20. DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

    Directory of Open Access Journals (Sweden)

    Matthew E Pamenter

    Full Text Available During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra. Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs, which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed. DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA. Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS

  1. Sulfur removal from fuel using zeolites/polyimide mixed matrix membrane adsorbents

    International Nuclear Information System (INIS)

    Lin, Ligang; Wang, Andong; Dong, Meimei; Zhang, Yuzhong; He, Benqiao; Li, Hong

    2012-01-01

    Graphical abstract: Membrane adsorption process is proposed for sulfur removal. Three-dimensional network structure is key to fulfill adsorption function of MMMs, which adsorption/desorption behavior is markedly related with binding force with sulfur molecules. Highlights: ► Membrane adsorption process is proposed for sulfur removal. ► Three-dimensional network structure of MMMs is key to fulfill adsorption function. ► Adsorption/desorption behavior is markedly related with binding force. - Abstract: A novel membrane adsorption process was proposed for the sulfur removal from fuels. The mixed matrix membranes (MMMs) adsorbents composed of polyimide (PI) and various Y zeolites were prepared. By the detailed characterization of FT-IR, morphology, thermal and mechanical properties of MMMs adsorbents, combining the adsorption and desorption behavior research, the process–structure–function relationship was discussed. Field-emission scanning electron microscope (FESEM) images show that the functional particles are incorporated into the three-dimensional network structure. MMMs adsorbents with 40% of zeolites content possess better physical properties, which was confirmed by mechanical strength and thermo stability analysis. Influence factors including post-treatment, content of incorporated zeolites, adsorption time, temperature, initial sulfur concentration as well as sulfur species on the adsorption performance of MMMs adsorbents have been evaluated. At 4 wt.% zeolites content, adsorption capacity for NaY/PI, AgY/PI and CeY/PI MMMs adsorbents come to 2.0, 7.5 and 7.9 mg S/g, respectively. And the regeneration results suggest that the corresponding spent membranes can recover about 98%, 90% and 70% of the desulfurization capacity, respectively. The distinct adsorption and desorption behavior of MMMs adsorbents with various functional zeolites was markedly related with their various binding force and binding mode with sulfur compounds.

  2. Development and characterization of polyethersulfone/TiO2 mixed matrix membranes for CO2/CH4 separation

    Science.gov (United States)

    Galaleldin, S.; Mannan, H. A.; Mukhtar, H.

    2017-12-01

    In this study, mixed matrix membranes comprised of polyethersulfone as the bulk polymer phase and titanium dioxide (TiO2) nanoparticles as the inorganic discontinuous phase were prepared for CO2/CH4 separation. Membranes were synthesized at filler loading of 0, 5, 10 and 15 wt % via dry phase inversion method. Morphology, chemical bonding and thermal characteristics of membranes were scrutinized utilizing different techniques, namely: Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform InfraRed (FTIR) spectra and Thermogravimetric analysis (TGA) respectively. Membranes gas separation performance was evaluated for CO2 and CH4 gases at 4 bar feed pressure. The highest separation performance was achieved by mixed matrix membrane (MMM) at 5 % loading of TiO2.

  3. Diabetes mellitus type 1

    OpenAIRE

    Desta, Semere Tekeste

    2017-01-01

    Høgskulen på Vestlandet Avdeling for helsefag for sykepleiere Tittel: Diabetes type 1 Bakgrunn for val av tema: I 2000 var det ca. 130 000 personer i Norge med diabetes, av disse hadde ca. 20 000 diabetes type 1. I dag er det ca. 230 000 personer som har diabetes i Norge. Av disse ca. 28 000 type 1 diabetes. Tallet viser hvor alvorlig sykdommen er, fordi det har vært og fortsatt er, en økning av antall diabetikere i Norge. Type 1 diabetes kan komme i alle aldersgrupper, men vanligvis...

  4. Mixed-matrix membranes containing an azine-linked covalent organic framework: Influence of the polymeric matrix on post-combustion CO 2 -capture

    NARCIS (Netherlands)

    Shan, Meixia; Seoane de la Cuesta, Beatriz; Andres-Garcia, Eduardo; Kapteijn, Freek; Gascon, Jorge

    2018-01-01

    The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO2 from N2. To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and

  5. Dimerization Efficiency of Canine Distemper Virus Matrix Protein Regulates Membrane-Budding Activity.

    Science.gov (United States)

    Bringolf, Fanny; Herren, Michael; Wyss, Marianne; Vidondo, Beatriz; Langedijk, Johannes P; Zurbriggen, Andreas; Plattet, Philippe

    2017-08-15

    Paramyxoviruses rely on the matrix (M) protein to orchestrate viral assembly and budding at the plasma membrane. Although the mechanistic details remain largely unknown, structural data suggested that M dimers and/or higher-order oligomers may facilitate membrane budding. To gain functional insights, we employed a structure-guided mutagenesis approach to investigate the role of canine distemper virus (CDV) M protein self-assembly in membrane-budding activity. Three six-alanine-block (6A-block) mutants with mutations located at strategic oligomeric positions were initially designed. While the first one includes residues potentially residing at the protomer-protomer interface, the other two display amino acids located within two distal surface-exposed α-helices proposed to be involved in dimer-dimer contacts. We further focused on the core of the dimeric interface by mutating asparagine 138 (N138) to several nonconservative amino acids. Cellular localization combined with dimerization and coimmunopurification assays, performed under various denaturing conditions, revealed that all 6A-block mutants were impaired in self-assembly and cell periphery accumulation. These phenotypes correlated with deficiencies in relocating CDV nucleocapsid proteins to the cell periphery and in virus-like particle (VLP) production. Conversely, all M-N138 mutants remained capable of self-assembly, though to various extents, which correlated with proper accumulation and redistribution of nucleocapsid proteins at the plasma membrane. However, membrane deformation and VLP assays indicated that the M-N138 variants exhibiting the most reduced dimerization propensity were also defective in triggering membrane remodeling and budding, despite proper plasma membrane accumulation. Overall, our data provide mechanistic evidence that the efficiency of CDV M dimerization/oligomerization governs both cell periphery localization and membrane-budding activity. IMPORTANCE Despite the availability of

  6. Metal-organic frameworks in mixed-matrix membranes for gas separation.

    Science.gov (United States)

    Tanh Jeazet, Harold B; Staudt, Claudia; Janiak, Christoph

    2012-12-14

    Mixed-matrix membranes (MMMs) with metal-organic frameworks (MOFs) as additives (fillers) exhibit enhanced gas permeabilities and possibly also selectivities when compared to the pure polymer. Polyimides (Matrimid®) and polysulfones are popular polymer matrices for MOF fillers. Presently investigated MOFs for MMMs include [Cu(SiF(6))(4,4'-BIPY)(2)], [Cu(3)(BTC)(2)(H(2)O)(3)] (HKUST-1, Cu-BTC), [Cu(BDC)(DMF)], [Zn(4)O(BDC)(3)] (MOF-5), [Zn(2-methylimidazolate)(2)] (ZIF-8), [Zn(purinate)(2)] (ZIF-20), [Zn(2-carboxyaldehyde imidazolate)(2)] (ZIF-90), Mn(HCOO)(2), [Al(BDC)(μ-OH)] (MIL-53(Al)), [Al(NH(2)-BDC)(μ-OH)] (NH(2)-MIL-53(Al)) and [Cr(3)O(BDC)(3)(F,OH)(H(2)O)(2)] (MIL-101) (4,4'-BIPY = 4,4'-bipyridine, BTC = benzene-1,3,5-tricarboxylate, BDC = benzene-1,4-dicarboxylate, terephthalate). MOF particle adhesion to polyimide and polysulfone organic polymers does not represent a problem. MOF-polymer MMMs are investigated for the permeability of the single gases H(2), N(2), O(2), CH(4), CO(2) and of the gas mixtures O(2)/N(2), H(2)/CH(4), CO(2)/CH(4), H(2)/CO(2), CH(4)/N(2) and CO(2)/N(2) (preferentially permeating gas named first). Permeability increases can be traced to the MOF porosity. Since the porosity of MOFs can be tuned very precisely, which is not possible with polymeric material, MMMs offer the opportunity of significantly increasing the selectivity compared to the pure polymeric matrix. Additionally in most of the cases the permeability is increased for MMM membranes compared to the pure polymer. Addition of MOFs to polymers in MMMs easily yields performances similar to the best polymer membranes and gives higher selectivities than those reported to date for any pure MOF membrane for the same gas separation. MOF-polymer MMMs allow for easier synthesis and handability compared to pure MOF membranes.

  7. Diabetes Type 1

    Science.gov (United States)

    Diabetes means your blood glucose, or blood sugar, levels are too high. With type 1 diabetes, your pancreas does not make insulin. Insulin is ... kidneys, nerves, and gums and teeth. Type 1 diabetes happens most often in children and young adults ...

  8. Type 1 Diabetes Facts

    Science.gov (United States)

    ... Affiliates JDRF Celebrity Ambassadors JDRF Logo Usage Contact Us Donate Events More Type 1 Diabetes Facts Type 1 diabetes (T1D) is an autoimmune ... about Insulin and T1D Learn More What Is Diabetes? Causes of T1D The Complexity of Diagnosing ... US CAREERS NEWSROOM FOR RESEARCHERS © JDRF 2018 • Privacy Policy • ...

  9. Mixed Matrix Membranes of Boron Icosahedron and Polymers of Intrinsic Microporosity (PIM-1) for Gas Separation.

    Science.gov (United States)

    Khan, Muntazim Munir; Shishatskiy, Sergey; Filiz, Volkan

    2018-01-02

    This work reports on the preparation and gas transport performance of mixed matrix membranes (MMMs) based on the polymer of intrinsic microporosity (PIM-1) and potassium dodecahydrododecaborate (K₂B 12 H 12 ) as inorganic particles (IPs). The effect of IP loading on the gas separation performance of these MMMs was investigated by varying the IP content (2.5, 5, 10 and 20 wt %) in a PIM-1 polymer matrix. The derived MMMs were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), single gas permeation tests and sorption measurement. The PIM1/K₂B 12 H 12 MMMs show good dispersion of the IPs (from 2.5 to 10 wt %) in the polymer matrix. The gas permeability of PIM1/K₂B 12 H 12 MMMs increases as the loading of IPs increases (up to 10 wt %) without sacrificing permselectivity. The sorption isotherm in PIM-1 and PIM1/K₂B 12 H 12 MMMs demonstrate typical dual-mode sorption behaviors for the gases CO₂ and CH₄.

  10. Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

    Energy Technology Data Exchange (ETDEWEB)

    Uctug, Fehmi Goerkem, E-mail: gorkem.uctug@bahcesehir.edu.t [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom); Holmes, Stuart M. [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom)

    2011-10-01

    Highlights: > We investigated the availability of PVA-mordenite membranes for DMFC use. > We measured the methanol permeability of PVA-mordenite membranes via pervaporation. > We did the fuel cell testing of these membranes, which had not been done before. > We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. > Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117{sup TM} whereas their methanol permeability was at least two orders of magnitude lower than Nafion117{sup TM}. DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

  11. Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

    International Nuclear Information System (INIS)

    Uctug, Fehmi Goerkem; Holmes, Stuart M.

    2011-01-01

    Highlights: → We investigated the availability of PVA-mordenite membranes for DMFC use. → We measured the methanol permeability of PVA-mordenite membranes via pervaporation. → We did the fuel cell testing of these membranes, which had not been done before. → We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. → Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117 TM whereas their methanol permeability was at least two orders of magnitude lower than Nafion117 TM . DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

  12. Study on the Fouling Behavior of Polyethylene and Silica Nanoparticles Mixed Matrix Membranes in Filtration of Humic Acid Solution

    Directory of Open Access Journals (Sweden)

    Ali Akbari

    2016-09-01

    Full Text Available Because most contaminants in water create strong interactions with hydrophobic surfaces, there are usually problems such as flux decline and pore blocking in polyethylene (PE membranes due to irreversible adsorption of foulants on their intrinsic hydrophobic surface. Therefore, in this work, attempts were made to improve the properties of PE membranes in terms of water flux and membrane fouling resistance by dispersion of silica nanoparticles (NPs. First, NPs were synthesized by sol-gel method at two concentrations of ammonia (0.5 and 1 mol/L. The synthesized NPs with smaller size were used to fabricate the mixed matrix PE membranes containing 0, 0.5, 1 and 2 wt% NPs. FE-SEM and EDX analyses were employed to evaluate the morphology and structure of the fabricated membranes and confirmed the presence of NPs in the membranes matrix. The results of pure water flux test revealed that the membrane containing 1 wt% NPs displayed the maximum flux of 30 L/m2.h. Furthermore, the performance and fouling behaviors of membranes during filtration of humic acid solution, one of the most important contaminants of water resources, were studied using a classical fouling model. Fouling mechanism analysis showed that for neat and NPs-embedded membranes containing 0.5 and 2 wt% NPs, the best fit of the data was obtained by cake layer formation as well as the intermediate blocking mechanisms. However, the best fit of the experimental data of NPs-embedded membrane containing 1 wt% occurred with only cake layer formation mechanism. The investigation on membrane fouling resistance showed that 1 wt% NPs-embedded membrane displayed 58% maximum flux recovery and 52% reversibility to total fouling ratio, respectively.

  13. Type 1 diabetes

    DEFF Research Database (Denmark)

    Green, Anders; Kyvik, Kirsten Ohm

    2001-01-01

    Prediction of Type 1 diabetes at individual level is relevant for any possible intervention before clinical disease develops. Currently available markers of Type 1 diabetes include genetic specificities and immune markers, in addition to a positive family history. This chapter reviews the measures...... and methods of importance in predicting Type 1 diabetes. Based on numerical examples it is demonstrated that available markers have a low level of performance, even when combined. Even so, combined marker information may allow for the identification of the large majority of the general population who...... is at very low disease risk. The impact at population level of predicting Type 1 diabetes varies between societies because the performance of markers depends on levels of disease risk and distribution of markers within a population. The incorporation of the influence of non-genetic etiological factors may...

  14. Type 1 diabetes

    OpenAIRE

    Atkinson, Mark A; Eisenbarth, George S; Michels, Aaron W

    2013-01-01

    Over the past decade, knowledge of the pathogenesis and natural history of type 1 diabetes has grown substantially, particularly with regard to disease prediction and heterogeneity, pancreatic pathology, and epidemiology. Technological improvements in insulin pumps and continuous glucose monitors help patients with type 1 diabetes manage the challenge of lifelong insulin administration. Agents that show promise for averting debilitating disease-associated complications have also been identifi...

  15. Localized ridge defect augmentation using human pericardium membrane and demineralized bone matrix.

    Science.gov (United States)

    Vidyadharan, Arun Kumar; Ravindran, Anjana

    2014-01-01

    Patient wanted to restore her lost teeth with implants in the lower left first molar and second premolar region. Cone beam computerized tomography (CBCT) revealed inadequate bone width and height around future implant sites. The extraction socket of second premolar area revealed inadequate socket healing with sparse bone fill after 4 months of extraction. To evaluate the clinical feasibility of using a collagen physical resorbable barrier made of human pericardium (HP) to augment localized alveolar ridge defects for the subsequent placement of dental implants. Ridge augmentation was done in the compromised area using Puros® demineralized bone matrix (DBM) Putty with chips and an HP allograft membrane. Horizontal (width) and vertical hard tissue measurements with CBCT were recorded on the day of ridge augmentation surgery, 4 month and 7 months follow-up. Intra oral periapical taken 1 year after implant installation showed minimal crestal bone loss. Bone volume achieved through guided bone regeneration was a gain of 4.8 mm horizontally (width) and 6.8 mm vertically in the deficient ridge within a period of 7 months following the procedure. The results suggested that HP Allograft membrane may be a suitable component for augmentation of localized alveolar ridge defects in conjunction with DBM with bone chips.

  16. Computational Screening of MOF-Based Mixed Matrix Membranes for CO2/N2 Separations

    Directory of Open Access Journals (Sweden)

    Zeynep Sumer

    2016-01-01

    Full Text Available Atomically detailed simulations were used to examine CO2/N2 separation potential of metal organic framework- (MOF- based mixed matrix membranes (MMMs in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2 separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2 selectivities and higher CO2 permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2 permeabilities but high CO2 selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2 permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2 separation applications.

  17. Mixed Matrix Membranes for O2/N2 Separation: The Influence of Temperature

    Directory of Open Access Journals (Sweden)

    Ana Fernández-Barquín

    2016-05-01

    Full Text Available In this work, mixed matrix membranes (MMMs composed of small-pore zeolites with various topologies (CHA (Si/Al = 5, LTA (Si/Al = 1 and 5, and Rho (Si/Al = 5 as dispersed phase, and the hugely permeable poly(1-trimethylsilyl-1-propyne (PTMSP as continuous phase, have been synthesized via solution casting, in order to obtain membranes that could be attractive for oxygen-enriched air production. The O2/N2 gas separation performance of the MMMs has been analyzed in terms of permeability, diffusivity, and solubility in the temperature range of 298–333 K. The higher the temperature of the oxygen-enriched stream, the lower the energy required for the combustion process. The effect of temperature on the gas permeability, diffusivity, and solubility of these MMMs is described in terms of the Arrhenius and Van’t Hoff relationships with acceptable accuracy. Moreover, the O2/N2 permselectivity of the MMMs increases with temperature, the O2/N2 selectivities being considerably higher than those of the pure PTMSP. In consequence, most of the MMMs prepared in this work exceeded the Robeson’s upper bound for the O2/N2 gas pair in the temperature range under study, with not much decrease in the O2 permeabilities, reaching O2/N2 selectivities of up to 8.43 and O2 permeabilities up to 4,800 Barrer at 333 K.

  18. Modeling the Effects of Interfacial Characteristics on Gas Permeation Behavior of Nanotube-Mixed Matrix Membranes.

    Science.gov (United States)

    Chehrazi, Ehsan; Sharif, Alireza; Omidkhah, Mohammadreza; Karimi, Mohammad

    2017-10-25

    Theoretical approaches that accurately predict the gas permeation behavior of nanotube-containing mixed matrix membranes (nanotube-MMMs) are scarce. This is mainly due to ignoring the effects of nanotube/matrix interfacial characteristics in the existing theories. In this paper, based on the analogy of thermal conduction in polymer composites containing nanotubes, we develop a model to describe gas permeation through nanotube-MMMs. Two new parameters, "interfacial thickness" (a int ) and "interfacial permeation resistance" (R int ), are introduced to account for the role of nanotube/matrix interfacial interactions in the proposed model. The obtained values of a int , independent of the nature of the permeate gas, increased by increasing both the nanotubes aspect ratio and polymer-nanotube interfacial strength. An excellent correlation between the values of a int and polymer-nanotube interaction parameters, χ, helped to accurately reproduce the existing experimental data from the literature without the need to resort to any adjustable parameter. The data includes 10 sets of CO 2 /CH 4 permeation, 12 sets of CO 2 /N 2 permeation, 3 sets of CO 2 /O 2 permeation, and 2 sets of CO 2 /H 2 permeation through different nanotube-MMMs. Moreover, the average absolute relative errors between the experimental data and the predicted values of the proposed model are very small (less than 5%) in comparison with those of the existing models in the literature. To the best of our knowledge, this is the first study where such a systematic comparison between model predictions and such extensive experimental data is presented. Finally, the new way of assessing gas permeation data presented in the current work would be a simple alternative to complex approaches that are usually utilized to estimate interfacial thickness in polymer composites.

  19. Fabrication of high flux and antifouling mixed matrix fumarate-alumoxane/PAN membranes via electrospinning for application in membrane bioreactors

    Science.gov (United States)

    Moradi, Golshan; Zinadini, Sirus; Rajabi, Laleh; Dadari, Soheil

    2018-01-01

    The nanofibrous Polyacrylonitrile (PAN) membranes embedded with fumarate-alumoxane (Fum-A) nanoparticles were prepared via electrospinning technique as high flux and antifouling membranes for membrane bioreactor (MBR) applications. The effect of Fum-A nanoparticles on membrane morphology, surface hydrophilicity, pure water flux, effluent turbidity and the antifouling property was investigated. Fum-A is a carboxylate-alumoxane nanoparticle covered by extra hydroxyl and carboxylate groups on its surface. By embedding Fum-A nanoparticles into the spinning solution, the surface hydrophilicity and pure water flux of the resulted membranes were improved. The smooth surface of fibers at the low amount of nanoparticles and the agglomeration of nanoparticles at their high concentration were shown in SEM images of the membranes surface. The energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) analysis of the prepared Fum-A/PAN membrane confirmed the presence of carboxylate and hydroxyl functional groups of Fum-A nanoparticles on the surface of the Fum-A nanoparticles containing membrane. The results obtained from the filtration of activated sludge suspension revealed that by addition of a low amount of Fum-A nanoparticles, the irreversible fouling was significantly decreased due to the higher hydrophilicity. The Fum-A/PAN membranes showed superior permeate flux and antifouling properties compared to bare electrospun PAN membrane. Finally, 2 wt.% Fum-A/PAN membrane exhibited the highest FRR of 96% and the lowest irreversible fouling of 4% with excellent durability of antifouling property during twenty repeated activated sludge filtrations.

  20. Diabetes mellitus type 1

    OpenAIRE

    Tøraasen, Lisa Vangen; Al-Sultan, Zainab

    2014-01-01

    Bacheloroppgave i sykepleie, 2014 Hvert år blir rundt 600 nordmenn diagnostisert med sykdommen diabetes type 1, og Norge er et av landene i verden med størst andel av barnediabetes. I dag er det 15 000- 20 000 personer i Norge som har diabetes type 1, og antall barn som får diabetes har fordoblet seg de siste 30 årene (Diabetesforbundet, 2014). Problemstillingen vår gikk ut på hvordan sykepleiere kan veilede og undervise ungdom med nyoppdaget diabetes type på sykehus. Ut i fra litteraturst...

  1. Diabetes mellitus type 1

    OpenAIRE

    Tøraasen, Lisa Vangen; Al-Sultan, Zainab

    2014-01-01

    Hvert år blir rundt 600 nordmenn diagnostisert med sykdommen diabetes type 1, og Norge er et av landene i verden med størst andel av barnediabetes. I dag er det 15 000- 20 000 personer i Norge som har diabetes type 1, og antall barn som får diabetes har fordoblet seg de siste 30 årene (Diabetesforbundet, 2014). Problemstillingen vår gikk ut på hvordan sykepleiere kan veilede og undervise ungdom med nyoppdaget diabetes type på sykehus. Ut i fra litteraturstudiet har vi arbeidet oss frem for å ...

  2. The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke Hansen

    2002-01-01

    Normal human B lymphocytes are known to activate the alternative pathway (AP) of complement, leading to C3-fragment deposition and membrane attack complex (MAC) formation. The process is mediated via complement receptor type 2 (CR2, CD21), with complement receptor type 1 (CR1, CD35) playing...... a subsidiary role. In this study, we examine the relative contributions of CR1 and CR2 to the deposition of C3 fragments and MAC on B lymphocytes under circumstances where all complement pathways are operational. C3-fragment deposition and MAC formation were assessed on human peripheral B lymphocytes...... in the presence of 30% autologous serum. Blocking the CR2 ligand-binding site with monoclonal antibody (mAb) FE8 resulted in significant reduction (37.9+/-11.9%) in C3-fragment deposition, whereas MAC formation was only marginally affected (12.1+/-22.2% reduction). Blocking the CR1 binding-site resulted...

  3. Revealing Transient Concentration of CO2 in a Mixed Matrix Membrane by IR Microimaging and Molecular Modeling

    KAUST Repository

    Hwang, Seungtaik

    2018-02-21

    Through IR microimaging the spatially and temporally resolved development of the CO2 concentration in a ZIF-8@6FDA-DAM mixed matrix membrane was visualized during transient adsorption. By recording the evolution of the CO2 concentration, it is observed that the CO2 molecules propagate from the ZIF-8 filler, which acts as a transport

  4. Revealing Transient Concentration of CO2 in a Mixed Matrix Membrane by IR Microimaging and Molecular Modeling

    KAUST Repository

    Hwang, Seungtaik; Semino, Rocio; Seoane, Beatriz; Zahan, Marufa; Chmelik, Christian; Valiullin, Rustem; Bertmer, Marko; Haase, Jü rgen; Kapteijn, Freek; Gascon, Jorge; Maurin, Guillaume; Kä rger, Jö rg

    2018-01-01

    Through IR microimaging the spatially and temporally resolved development of the CO2 concentration in a ZIF-8@6FDA-DAM mixed matrix membrane was visualized during transient adsorption. By recording the evolution of the CO2 concentration, it is observed that the CO2 molecules propagate from the ZIF-8 filler, which acts as a transport

  5. Type 1 narcolepsy

    DEFF Research Database (Denmark)

    Degn, Matilda; Kornum, Birgitte Rahbek

    2015-01-01

    Type 1 narcolepsy is a sleep disorder characterized by excessive daytime sleepiness with unintentional sleep attacks and cataplexy. The disorder is caused by a loss of hypocretinergic neurons in the brain. The specific loss of these neurons in narcolepsy is thought to result from an autoimmune...

  6. The central role of vascular extracellular matrix and basement membrane remodeling in metabolic syndrome and type 2 diabetes: the matrix preloaded

    Directory of Open Access Journals (Sweden)

    Tyagi Suresh C

    2005-06-01

    Full Text Available Abstract The vascular endothelial basement membrane and extra cellular matrix is a compilation of different macromolecules organized by physical entanglements, opposing ionic charges, chemical covalent bonding, and cross-linking into a biomechanically active polymer. These matrices provide a gel-like form and scaffolding structure with regional tensile strength provided by collagens, elasticity by elastins, adhesiveness by structural glycoproteins, compressibility by proteoglycans – hyaluronans, and communicability by a family of integrins, which exchanges information between cells and between cells and the extracellular matrix of vascular tissues. Each component of the extracellular matrix and specifically the capillary basement membrane possesses unique structural properties and interactions with one another, which determine the separate and combined roles in the multiple diabetic complications or diabetic opathies. Metabolic syndrome, prediabetes, type 2 diabetes mellitus, and their parallel companion (atheroscleropathy are associated with multiple metabolic toxicities and chronic injurious stimuli. The adaptable quality of a matrix or form genetically preloaded with the necessary information to communicate and respond to an ever-changing environment, which supports the interstitium, capillary and arterial vessel wall is individually examined.

  7. Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix

    DEFF Research Database (Denmark)

    Kehlet, Stephanie N.; Willumsen, Nicholas; Armbrecht, Gabriele

    2018-01-01

    The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small...... collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I...... an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies....

  8. MOF-mixed matrix membranes : precise dispersion of MOF particles with better compatibility via a particle fusion approach for enhanced gas separation properties

    NARCIS (Netherlands)

    Shahid, Salman; Nijmeijer, Kitty; Nehache, Sabrina; Vankelecom, Ivo; Deratani, Andre; Quemener, Damien

    2015-01-01

    Mixed matrix membranes (MMMs) incorporating conventional fillers frequently suffer from insufficient adhesion between the polymer matrix and the fillers. This often results in the formation of non-selective voids at the filler/polymer interface, which decreases the performance of the membrane. A

  9. MOF-mixed matrix membranes: Precise dispersion of MOF particles with better compatibility via a particle fusion approach for enhanced gas separation properties

    NARCIS (Netherlands)

    Shahid, S.; Nijmeijer, Dorothea C.; Nehache, Sabrina; Vankelecom, Ivo; Deratani, Andre; Quemener, Damien

    2015-01-01

    Mixed matrix membranes (MMMs) incorporating conventional fillers frequently suffer from insufficient adhesion between the polymer matrix and the fillers. This often results in the formation of non-selective voids at the filler/polymer interface, which decreases the performance of the membrane. A

  10. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.

    2014-07-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near the limiting pore apertures of ZIFs, there have been few demonstrations of improved gas separation properties over pure polymer membranes when utilizing ZIF materials in composite membranes for CO2-based gas separations. Here, we report a study of composite ZIF/polymer membranes, containing mixed-linker ZIF materials with ZIF-8 crystal topologies but composed of different organic linker compositions. Characterization of the mixed-linker ZIFs shows that the mixed linker approach offers control over the porosity and pore size distribution of the materials, as determined from nitrogen physisorption and Horváth-Kawazoe analysis. Single gas permeation measurements on mixed-matrix membranes reveal that inclusion of mixed-linker ZIFs yields membranes with better ideal CO2/CH4 selectivity than membranes containing ZIF-8. This improvement is shown to likely occur from enhancement in the diffusion selectivity of the membranes associated with controlling the pore size distribution of the ZIF filler. Mixed-gas permeation experiments show that membranes with mixed-linker ZIFs display an effective plasticization resistance that is not typical of the pure polymeric matrix. Overall, we demonstrate that mixed-linker ZIFs can improve the gas separation properties in composite membranes and may be applicable to aggressive CO2 concentrations in natural gas feeds. © 2013 Elsevier Inc. All rights reserved.

  11. Mixed-Matrix Membranes containing an Azine-Linked Covalent Organic Framework: Influence of the polymeric matrix on Post-Combustion CO 2 -capture

    KAUST Repository

    Shan, Meixia

    2017-12-07

    The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO2 from N2. To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and three different polymers as continuous phase: low flux-mid selectivity Matrimid®, mid flux-high selectivity Polyactive™ and high flux-low selectivity 6FDA:DAM. The homogeneous distribution of ACOF-1 together with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO2/N2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While for Matrimid® and 6FDA:DAM an overall enhancement of the polymer\\'s separation properties could be achieved, in case of Polyactive™ penetration of the more flexible polymer into the COF porosity resulted in a decreased membrane permeability. The best improvement was obtained for Matrimid®-based MMMs, for which a selectivity increase from 29 to 35, together with an enhancement in permeability from 9.5 to 17.7 Barrer for 16wt% COF loading, was observed. Our results demonstrate that the combination of the filler-polymeric matrix pair chosen is crucial. For a given filler the polymer performance improvement strongly depends on the polymeric matrix selected, where a good match between the discontinuous and continuous phase, both in the terms of compatibility and gas separation properties, is necessary to optimize membrane performance.

  12. [Morphology of basement membrane and associated matrix proteins in normal and pathological tissues].

    Science.gov (United States)

    Nerlich, A

    1995-01-01

    Basement membranes (BM) are specialized structures of the extracellular matrix. Their composition is of particular importance for the maintenance of normal morphological and functional properties of a multitude of organs and tissue systems and it is thus required for regular homeostasis of body function. Generally, they possess three main functions, i.e. participation in the maintenance of tissue structure, control of fluid and substrate exchange, and regulation of cell growth and differentiation. BMs are made up by various components which are in part specifically localized within the BM zone, or which represent ubiquitous matrix constituents with specific quantitative and/or qualitative differences in their localization. On the basis of a thorough immunohistochemical analysis of normal and diseased tissues, we provide here a concept of "functional morphology/pathomorphology" of the different BM components analyzed: 1.) The ubiquitous BM-constituent collagen IV primarily stabilizes the BM-zone and thus represents the "backbone" of the BM providing mechanical strength. Its loss leads to cystic tissue transformation as it is evidenced from the analysis of polycystic nephropathies. Thus, in other cystic tissue transformations a similar formal pathogenesis may be present. 2.) The specific localization of collagen VII as the main structural component of anchoring fibrils underlines the mechanical anchoring function of this collagenous protein. Defects in this protein lead to hereditary epidermolysis. The rapid re-occurrence of epidermal collagen VII during normal human wound healing indicates a quick reconstitution of the mechanical tensile strength of healing wounds. 3.) The BM-specific heparan sulfate proteoglycan (HSPG, Perlecan) with its highly negative anionic charge can be assumed to exert filter control. This assumption is corroborated by the localizatory findings of a preferential deposition of HSPG in endothelial and particularly in glomerular BM. Similarly

  13. Modified ZIF-8 mixed matrix membrane for CO2/CH4 separation

    Science.gov (United States)

    Nordin, Nik Abdul Hadi Md; Ismail, Ahmad Fauzi; Misdan, Nurasyikin; Nazri, Noor Aina Mohd

    2017-10-01

    Tunability of metal-organic frameworks (MOFs) properties enables them to be tailored for specific applications. In this study, zeolitic imidazole framework 8 (ZIF-8), sub-class of MOF, underwent pre-synthesis and post-synthesis modifications. The pre-synthesis modification using GO (ZIF-8/GO) shows slight decrease in textural properties, while the post-synthesis modification using amine solution (ZIF-8/NH2) resulted in superior BET surface area and pore volume. Mixed matrix membranes (MMMs) derived from polysulfone (PSf) and the modified ZIF-8s were then prepared via dry/wet phase inversion. The polymer chain flexibility of the resulted MMMs shows rigidification, where ZIF-8/NH2 as filler resulting higher rigidification compared to ZIF-8/GO. The MMMs were further subjected to pure CO2 and CH4 gas permeation experiments. The PSf/ZIF-8/NH2 shows superior CO2/CH4 selectivity (88% increased) while sacrificing CO2 permeance due to combination of severe polymer chain rigidification and the presence of CO2-philic group, amine. Whereas, the PSf/ZIF-8/GO possess 64% increase in CO2 permeance without notable changes in CO2/CH4 selectivity.

  14. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.

    2011-02-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  15. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.; Lee, Jong Suk; Bae, Tae-Hyun; Ward, Jason K.; Johnson, J.R.; Jones, Christopher W.; Nair, Sankar; Koros, William J.

    2011-01-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  16. Enhanced aging properties of HKUST-1 in hydrophobic mixed-matrix membranes for ammonia adsorption.

    Science.gov (United States)

    DeCoste, Jared B; Denny, Michael S; Peterson, Gregory W; Mahle, John J; Cohen, Seth M

    2016-04-21

    Metal-organic frameworks (MOFs) in their free powder form have exhibited superior capacities for many gases when compared to other materials, due to their tailorable functionality and high surface areas. Specifically, the MOF HKUST-1 binds small Lewis bases, such as ammonia, with its coordinatively unsaturated copper sites. We describe here the use of HKUST-1 in mixed-matrix membranes (MMMs) prepared from polyvinylidene difluoride (PVDF) for the removal of ammonia gas. These MMMs exhibit ammonia capacities similar to their hypothetical capacities based on the weight percent of HKUST-1 in each MMM. HKUST-1 in its powder form is unstable toward humid conditions; however, upon exposure to humid environments for prolonged periods of time, the HKUST-1 MMMs exhibit outstanding structural stability, and maintain their ammonia capacity. Overall, this study has achieved all of the critical and combined elements for real-world applications of MOFs: high MOF loadings, fully accessible MOF surfaces, enhanced MOF stabilization, recyclability, mechanical stability, and processability. This study is a critical step in advancing MOFs to a stable, usable, and enabling technology.

  17. Socket Preservation with d-PTFE Membrane: Histologic Analysis of the Newly Formed Matrix at Membrane Removal.

    Science.gov (United States)

    Laurito, Domenico; Cugnetto, Riccardo; Lollobrigida, Marco; Guerra, Fabrizio; Vestri, Annarita; Gianno, Francesca; Bosco, Sandro; Lamazza, Luca; De Biase, Alberto

    This study aimed to evaluate the efficacy of an exposed high-density polytetrafluoroethylene (d-PTFE) membrane in preventing epithelial migration in postextraction sockets. For this purpose, a histologic description of the newly formed soft tissue underlying the membrane is presented. The periodontal status of the adjacent teeth was also evaluated to assess the gingival response. Ten premolar extraction sockets were treated. After tooth extraction, the sockets were filled with nanocrystalline hydroxyapatite and covered with d-PTFE membranes. Subperiosteal pockets were created to ensure the stability of the membranes. Membranes were left intentionally exposed and were atraumatically removed after 28 days. At that time, a bioptic specimen of the newly formed soft tissue under the membranes was taken. All the histologic samples showed a dense connective tissue without epithelial cells and no signs of foreign body reaction. No significant variation of the periodontal indices was observed on the teeth adjacent to the extraction sites. The study results indicate that exposed d-PTFE membranes can prevent epithelial migration in healing sockets without consequences on the periodontal health.

  18. High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations

    KAUST Repository

    Zhang, Chen

    2012-02-01

    We report significantly enhanced propylene/propane (C 3H 6/C 3H 8) selectivity in mixed matrix membranes fabricated using 6FDA-DAM polyimide and a zeolitic imidazolate framework (ZIF-8). Equilibrium isotherms and sorption kinetics of C 3H 6 and C 3H 8 at 35°C were studied on a 200nm commercially available ZIF-8 sample produced by BASF. Mixed matrix dense films were formed with 6FDA-DAM and 200nm BASF ZIF-8 particles. SEM imaging showed generally good adhesion between the ZIF-8 and 6FDA-DAM without the need for surface-treating ZIF-8. Pure gas permeation showed significantly enhanced mixed matrix ZIF-8/6FDA-DAM membrane C 3H 6/C 3H 8 separation performance over the pure 6FDA-DAM membrane performance. A C 3H 6 permeability of 56.2Barrer and C 3H 6/C 3H 8 ideal selectivity of 31.0 was found in ZIF-8/6FDA-DAM mixed matrix membrane with 48.0wt% ZIF-8 loading, which are 258% and 150% higher than the pure 6FDA-DAM membrane, respectively for permeability and selectivity. Permeation properties of C 3H 6 and C 3H 8 in ZIF-8 were back-calculated by the Maxwell model for composite permeability using pure gas permeation data, leading to a C 3H 6 permeability of 277Barrer and C 3H 6/C 3H 8 selectivity of 122. Mixed gas permeation also verified that selectivity enhancements were achievable in mixed gas environment by ZIF-8. © 2011 Elsevier B.V.

  19. High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations

    KAUST Repository

    Zhang, Chen; Dai, Ying; Johnson, Justin R.; Karvan, Oguz; Koros, William J.

    2012-01-01

    We report significantly enhanced propylene/propane (C 3H 6/C 3H 8) selectivity in mixed matrix membranes fabricated using 6FDA-DAM polyimide and a zeolitic imidazolate framework (ZIF-8). Equilibrium isotherms and sorption kinetics of C 3H 6 and C 3H 8 at 35°C were studied on a 200nm commercially available ZIF-8 sample produced by BASF. Mixed matrix dense films were formed with 6FDA-DAM and 200nm BASF ZIF-8 particles. SEM imaging showed generally good adhesion between the ZIF-8 and 6FDA-DAM without the need for surface-treating ZIF-8. Pure gas permeation showed significantly enhanced mixed matrix ZIF-8/6FDA-DAM membrane C 3H 6/C 3H 8 separation performance over the pure 6FDA-DAM membrane performance. A C 3H 6 permeability of 56.2Barrer and C 3H 6/C 3H 8 ideal selectivity of 31.0 was found in ZIF-8/6FDA-DAM mixed matrix membrane with 48.0wt% ZIF-8 loading, which are 258% and 150% higher than the pure 6FDA-DAM membrane, respectively for permeability and selectivity. Permeation properties of C 3H 6 and C 3H 8 in ZIF-8 were back-calculated by the Maxwell model for composite permeability using pure gas permeation data, leading to a C 3H 6 permeability of 277Barrer and C 3H 6/C 3H 8 selectivity of 122. Mixed gas permeation also verified that selectivity enhancements were achievable in mixed gas environment by ZIF-8. © 2011 Elsevier B.V.

  20. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China)

    2010-07-01

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO{sub 2}) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO{sub 3}H{sub 2} groups on OPTi and the -NH{sub 2} groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm{sup -1} for DMFC application and a reduced methanol permeability of 5 x 10{sup -7} cm{sup 2} s{sup -1} at a 2 M methanol feed. (author)

  1. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Science.gov (United States)

    Wu, Hong; Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO 2) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO 3H 2 groups on OPTi and the -NH 2 groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm -1 for DMFC application and a reduced methanol permeability of 5 × 10 -7 cm 2 s -1 at a 2 M methanol feed.

  2. Two barcodes encoded by the type-1 PDZ and by phospho-Ser312 regulate retromer/WASH-mediated sorting of the ß1-adrenergic receptor from endosomes to the plasma membrane.

    Science.gov (United States)

    Nooh, Mohammed M; Bahouth, Suleiman W

    2017-01-01

    Recycling of the majority of agonist-internalized GPCR is dependent on a type I-PDZ "barcode" in their C-tail. The recycling of wild-type (WT) ß 1 -AR is also dependent on its default "type-1 PDZ barcode", but trafficking of the ß 1 -AR is inhibited when PKA or its substrate serine at position 312 (Ser 312 ) are inactivated. We tested the hypothesis that phospho-Ser 312 provided a second barcode for ß 1 -AR sorting from endosomes to the plasma membrane by determining the role of retromer/WASH complexes in ß 1 -AR trafficking. Recycling of WT ß 1 -AR or WT ß 2 -AR was dependent on targeting the retromer to endosomal membranes via SNX3 and rab7a, and on complexing the retromer to the WASH pentamer via the C-tail of FAM21 (FAM21 C ). These maneuvers however, did not inhibit the recycling of a phospho-Ser 312 ß 1 -AR mimic ((S312D) ß 1 -AR). Knockdown of the trans-acting PDZ protein sorting nexin27 (SNX27) inhibited the recycling of WT ß 1 -AR and WT ß 2 -AR, but had no effect on (S312D) ß 1 -AR∆PDZ or on phosphorylation of WT ß 1 -AR by PKA at Ser 312 . However, depletion of FKBP15, a FAM21 C -binding endosomal protein, selectively inhibited WT ß 1 -AR but not ß 2 -AR recycling, suggesting divergence might exist in GPCR trafficking roadmaps. These results indicate that two barcodes are involved in sorting WT ß 1 -AR out of early endosomes. The first and antecedent "barcode" was the "type-1 PDZ", followed by a second reversible "phospho-Ser 312 " verification "barcode". This organization allows tight regulation of ß 1 -AR density to signaling intensity in conditions associated with aberrant ß 1 -AR signaling such as in hypertension and heart failure. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Membrane-type-3 matrix metalloproteinase (MT3-MMP functions as a matrix composition-dependent effector of melanoma cell invasion.

    Directory of Open Access Journals (Sweden)

    Olga Tatti

    Full Text Available In primary human melanoma, the membrane-type matrix metalloproteinase, MT3-MMP, is overexpressed in the most aggressive nodular-type tumors. Unlike MT1-MMP and MT2-MMP, which promote cell invasion through basement membranes and collagen type I-rich tissues, the function of MT3-MMP in tumor progression remains unclear. Here, we demonstrate that MT3-MMP inhibits MT1-MMP-driven melanoma cell invasion in three-dimensional collagen, while yielding an altered, yet MT1-MMP-dependent, form of expansive growth behavior that phenocopies the formation of nodular cell colonies. In melanoma cell lines originating from advanced primary or metastatic lesions, endogenous MT3-MMP expression was associated with limited collagen-invasive potential. In the cell lines with highest MT3-MMP expression relative to MT1-MMP, collagen-invasive activity was increased following stable MT3-MMP gene silencing. Consistently, MT3-MMP overexpression in cells derived from less advanced superficially spreading melanoma lesions, or in the MT3-MMP knockdown cells, reduced MT1-MMP-dependent collagen invasion. Rather than altering MT1-MMP transcription, MT3-MMP interacted with MT1-MMP in membrane complexes and reduced its cell surface expression. By contrast, as a potent fibrinolytic enzyme, MT3-MMP induced efficient invasion of the cells in fibrin, a provisional matrix component frequently found at tumor-host tissue interfaces and perivascular spaces of melanoma. Since MT3-MMP was significantly upregulated in biopsies of human melanoma metastases, these results identify MT3-MMP as a matrix-dependent modifier of the invasive tumor cell functions during melanoma progression.

  4. Membrane culture and reduced oxygen tension enhances cartilage matrix formation from equine cord blood mesenchymal stromal cells in vitro.

    Science.gov (United States)

    Co, C; Vickaryous, M K; Koch, T G

    2014-03-01

    Ongoing research is aimed at increasing cartilage tissue yield and quality from multipotent mesenchymal stromal cells (MSC) for the purpose of treating cartilage damage in horses. Low oxygen culture has been shown to enhance chondrogenesis, and novel membrane culture has been proposed to increase tissue yield and homogeneity. The objective of this study was to evaluate and compare the effect of reduced oxygen and membrane culture during in vitro chondrogenesis of equine cord blood (CB) MSC. CB-MSC (n = 5 foals) were expanded at 21% oxygen prior to 3-week differentiation in membrane or pellet culture at 5% and 21% oxygen. Assessment included histological examination (H&E, toluidine Blue, immunohistochemistry (IHC) for collagen type I and II), protein quantification by hydroxyproline assay and dimethylmethylene assay, and mRNA analysis for collagen IA1, collagen IIA1, collagen XA1, HIF1α and Sox9. Among treatment groups, 5% membrane culture produced neocartilage most closely resembling hyaline cartilage. Membrane culture resulted in increased wet mass, homogenous matrix morphology and an increase in total collagen content, while 5% oxygen culture resulted in higher GAG and type II collagen content. No significant differences were observed for mRNA analysis. Membrane culture at 5% oxygen produces a comparatively larger amount of higher quality neocartilage. Matrix homogeneity is attributed to a uniform diffusion gradient and reduced surface tension. Membrane culture holds promise for scale-up for therapeutic purposes, for cellular preconditioning prior to cytotherapeutic applications, and for modeling system for gas-dependent chondrogenic differentiation studies. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  5. Type 1 autoimmune pancreatitis.

    Science.gov (United States)

    Zen, Yoh; Bogdanos, Dimitrios P; Kawa, Shigeyuki

    2011-12-07

    Before the concept of autoimmune pancreatitis (AIP) was established, this form of pancreatitis had been recognized as lymphoplasmacytic sclerosing pancreatitis or non-alcoholic duct destructive chronic pancreatitis based on unique histological features. With the discovery in 2001 that serum IgG4 concentrations are specifically elevated in AIP patients, this emerging entity has been more widely accepted. Classical cases of AIP are now called type 1 as another distinct subtype (type 2 AIP) has been identified. Type 1 AIP, which accounts for 2% of chronic pancreatitis cases, predominantly affects adult males. Patients usually present with obstructive jaundice due to enlargement of the pancreatic head or thickening of the lower bile duct wall. Pancreatic cancer is the leading differential diagnosis for which serological, imaging, and histological examinations need to be considered. Serologically, an elevated level of IgG4 is the most sensitive and specific finding. Imaging features include irregular narrowing of the pancreatic duct, diffuse or focal enlargement of the pancreas, a peri-pancreatic capsule-like rim, and enhancement at the late phase of contrast-enhanced images. Biopsy or surgical specimens show diffuse lymphoplasmacytic infiltration containing many IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis. A dramatic response to steroid therapy is another characteristic, and serological or radiological effects are normally identified within the first 2 or 3 weeks. Type 1 AIP is estimated as a pancreatic manifestation of systemic IgG4-related disease based on the fact that synchronous or metachronous lesions can develop in multiple organs (e.g. bile duct, salivary/lacrimal glands, retroperitoneum, artery, lung, and kidney) and those lesions are histologically identical irrespective of the organ of origin. Several potential autoantigens have been identified so far. A Th2-dominant immune reaction and the activation of regulatory T-cells are assumed

  6. Type 1 autoimmune pancreatitis

    Directory of Open Access Journals (Sweden)

    Zen Yoh

    2011-12-01

    Full Text Available Abstract Before the concept of autoimmune pancreatitis (AIP was established, this form of pancreatitis had been recognized as lymphoplasmacytic sclerosing pancreatitis or non-alcoholic duct destructive chronic pancreatitis based on unique histological features. With the discovery in 2001 that serum IgG4 concentrations are specifically elevated in AIP patients, this emerging entity has been more widely accepted. Classical cases of AIP are now called type 1 as another distinct subtype (type 2 AIP has been identified. Type 1 AIP, which accounts for 2% of chronic pancreatitis cases, predominantly affects adult males. Patients usually present with obstructive jaundice due to enlargement of the pancreatic head or thickening of the lower bile duct wall. Pancreatic cancer is the leading differential diagnosis for which serological, imaging, and histological examinations need to be considered. Serologically, an elevated level of IgG4 is the most sensitive and specific finding. Imaging features include irregular narrowing of the pancreatic duct, diffuse or focal enlargement of the pancreas, a peri-pancreatic capsule-like rim, and enhancement at the late phase of contrast-enhanced images. Biopsy or surgical specimens show diffuse lymphoplasmacytic infiltration containing many IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis. A dramatic response to steroid therapy is another characteristic, and serological or radiological effects are normally identified within the first 2 or 3 weeks. Type 1 AIP is estimated as a pancreatic manifestation of systemic IgG4-related disease based on the fact that synchronous or metachronous lesions can develop in multiple organs (e.g. bile duct, salivary/lacrimal glands, retroperitoneum, artery, lung, and kidney and those lesions are histologically identical irrespective of the organ of origin. Several potential autoantigens have been identified so far. A Th2-dominant immune reaction and the activation of

  7. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    Directory of Open Access Journals (Sweden)

    Millward Jason M

    2007-09-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are thought to mediate cellular infiltration in central nervous system (CNS inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs. Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE, as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24 were downregulated. The two remaining MT-MMPs (MMP-14 and 25 were upregulated in whole tissue. Methods We used in vivo models of CNS inflammation and injury to study expression of MT-MMP and cytokine mRNA by real-time RT-PCR. Expression was also assessed in microglia sorted from CNS by flow cytometry, and in primary microglia cultures following treatment with IFNγ. Results We now confirm the expression pattern of MT-MMPs in the B6 mouse, independent of effects of adjuvant. We further show expression of all the MT-MMPs, except MMP-24, in microglia. Microglia isolated from mice with severe EAE showed statistically significant downregulation of MMP-15, 17 and 25 and lack of increase in levels of other MT-MMPs. Downregulation of MT-MMPs was also apparent following CNS injury. The pattern of regulation of MT-MMPs in neuroinflammation showed no association with expression of the proinflammatory cytokines TNFα, IL-1β, or IFNγ. Conclusion CNS inflammation and injury leads to downregulation in expression of the majority of MT-MMPs. Microglia in EAE showed a general downregulation of MT-MMPs, and our findings suggest that MT-MMP levels may

  8. Fabrication Parameters of Asymmetric Mixed Matrix Matrimid-MIL-53/PMHS Membrane for CO2/CH4 Separation

    Directory of Open Access Journals (Sweden)

    Fatereh Dorosti

    2017-03-01

    Full Text Available Asymmetrically mixed matrix Matrimid-MIL-53 membranes with silicone cover layer were fabricated. For better understanding of membrane fabrication process, three main parameters of fabrication, Matrimid concentration, silicone concentration and weight percentage of metal organic framework (MIL-53 particles, were optimized by an experimental design method. Cross-section SEM images were used to study the membrane structure and polymer-particles interface. Moreover, thermal resistance of the membranes and the existence of various bonds in them were investigated by FTIR and TGA analyses. The results showed that membranes had porous structure with finger-like morphology. At low and moderate percentages of particles, there were no non-selective voids observed at polymer-particles interface. The thermal resistance of membranes increased with the increase of MIL-53 weight percentage and the destruction temperature of polymer increased from 410°C to 450°C. The permeability tests results showed that the Matrimid (20% wt-MIL-53(15% wt/PMHS (10%wt membrane exhibited the highest level of CO2/CH4 selectivity (23.6. However, in the membrane with 30 wt% particles loading, selectivity decreased due to particles agglomeration and void formation. The experimental design results showed that the concentration of silicone in covering solution had significant effect. CO2 and CH4 permeability decreased and ideal selectivity of CO2/CH4 increased with silicone concentration enhancement. Although the Matrimid concentration had a little effect on CO2/CH4 ideal selectivity, its enhancement increased the selectivity of the gases. The optimization results showed the membrane with 17.8% of Matrimd polymer, 13.2% of silicone polymer and 15.5 wt% of MIL-53 particle displayed the highest selectivity and CO2 permeability.

  9. Type 1 Tyrosinaemia

    LENUS (Irish Health Repository)

    Mannion, MA

    2016-06-01

    Tyrosinaemia type 1 (TYR1, OMIM# 276700) is a rare autosomal recessive disease that results from an enzyme defect that leads to a deficiency in fumarylacetoacetase (FAH)1. We present 3 cases of TYR1 in the Irish population over a 9 year period, the only cases known to have been diagnosed in Ireland since 1989. The common presenting symptom was hypoglycaemia and the diagnosis was made by the identification of the pathognomonic biomarker succinylacetone on urine organic acid analysis. We discuss the clinical presentation, biochemical and genetic results including one novel mutation. We also highlight the importance of early initiation of Nitisinone (NTBC), which reduces the complications of TYR1 and the incidence of liver transplantation in this population2.

  10. Polymer-metal organic frameworks (MOFs) mixed matrix membranes for gas separation applications

    NARCIS (Netherlands)

    Shahid, S.

    2015-01-01

    The performance of polymeric membranes is often limited by a trade-off between membrane permeability and selectivity, the so-called Robeson upper bound. Additionally, in high pressure CO2 capture applications, excessive swelling of the polymer membrane often leads to plasticization resulting in

  11. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis

    Directory of Open Access Journals (Sweden)

    Chi-Hung Huang

    2009-12-01

    Full Text Available The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT, and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis.

  12. Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

    Directory of Open Access Journals (Sweden)

    Edson V. Perez

    2016-09-01

    Full Text Available Gas separation for industrial, energy, and environmental applications requires low energy consumption and small footprint technology to minimize operating and capital costs for the processing of large volumes of gases. Among the separation methods currently being used, like distillation, amine scrubbing, and pressure and temperature swing adsorption, membrane-based gas separation has the potential to meet these demands. The key component, the membrane, must then be engineered to allow for high gas flux, high selectivity, and chemical and mechanical stability at the operating conditions of feed composition, pressure, and temperature. Among the new type of membranes studied that show promising results are the inorganic-based and the metal-organic framework-based mixed-matrix membranes (MOF-MMMs. A MOF is a unique material that offers the possibility of tuning the porosity of a membrane by introducing diffusional channels and forming a compatible interface with the polymer. This review details the origins of these membranes and their evolution since the first inorganic/polymer and MOF/polymer MMMs were reported in the open literature. The most significant advancements made in terms of materials, properties, and testing conditions are described in a chronological fashion.

  13. The major basement membrane components localize to the chondrocyte pericellular matrix--a cartilage basement membrane equivalent?

    DEFF Research Database (Denmark)

    Kvist, Alexander J.; Nyström, Alexander; Hultenby, Kjell

    2007-01-01

    In this study, we demonstrate that articular cartilage chondrocytes are surrounded by the defining basement membrane proteins laminin, collagen type IV, nidogen and perlecan, and suggest that these form the functional equivalent of a basement membrane. We found by real-time PCR that mouse...... chondrocytes express these four cardinal components of basement membranes and demonstrated by immunohistochemistry that the proteins are present in bovine and mouse cartilage tissues and are deposited in a thin pericellular structure. Immunoelectron microscopy confirmed high laminin concentration...... becomes less distinct, especially in areas of obvious mechanical attrition. Interestingly, individual laminin subunits were located in different zones of the cartilage, with laminin alpha1 showing preferential localization around a select population of superficial layer chondrocytes. We propose...

  14. Separation of carbon dioxide from flue gas by mixed matrix membranes using dual phase microporous polymeric constituents.

    Science.gov (United States)

    Sekizkardes, Ali K; Kusuma, Victor A; Dahe, Ganpat; Roth, Elliot A; Hill, Lawrence J; Marti, Anne; Macala, Megan; Venna, Surendar R; Hopkinson, David

    2016-09-27

    This study presents the fabrication of a new mixed matrix membrane using two microporous polymers: a polymer of intrinsic microporosity PIM-1 and a benzimidazole linked polymer, BILP-101, and their CO 2 separation properties from post-combustion flue gas. 17, 30 and 40 wt% loadings of BILP-101 into PIM-1 were tested, resulting in mechanically stable films showing very good interfacial interaction due to the inherent H-bonding capability of the constituent materials. Gas transport studies showed that BILP-101/PIM-1 membranes exhibit high CO 2 permeability (7200 Barrer) and selectivity over N 2 (15). The selected hybrid membrane was further tested for CO 2 separation using actual flue gas from a coal-fired power plant.

  15. Towards Acid-Tolerated Ethanol Dehydration: Chitosan-Based Mixed Matrix Membranes Containing Cyano-Bridged Coordination Polymer Nanoparticles.

    Science.gov (United States)

    Wu, C-W; Kang, Chao-Hsiang; Lin, Yi-Feng; Tung, Kuo-Lun; Deng, Yu-Heng; Ahamad, Tansir; Alshehri, Saad M; Suzuki, Norihiro; Yamauchi, Yusuke

    2016-04-01

    Prussian blue (PB) nanoparticles, one of many cyano-bridged coordination polymers, are successfully incorporated into chitosan (CS) polymer to prepare PB/CS mixed matrix membranes (MMMs). The PB nanoparticles are uniformly distributed in the MMMs without the collapse of the original PB structure. As-prepared PB/CS MMMs are used for ethanol dehydration at 25 °C in the pervaporation process. The effect of loading PB in CS matrix on pervaporation performance is carefully investigated. The PB/CS membrane with 30 wt% PB loading shows the best performance with a permeate flux of 614 g. m-2 . h-1 and a separation factor of 1472. The pervaporation using our PB/CS membranes exhibits outstanding performance in comparison with the previously reported CS-based membranes and MMMs. Furthermore, the addition of PB allows PB/CS MMMs to be tolerant of acidic environment. The present work demonstrates good pervaporation performance of PB/CS MMMs for the separation of an ethanol/water (90:10 in wt%) solution. Our new system provides an opportunity for dehydration of bioethanol in the future.

  16. Enhanced selectivity in mixed matrix membranes for CO2 capture through efficient dispersion of amine-functionalized MOF nanoparticles

    Science.gov (United States)

    Ghalei, Behnam; Sakurai, Kento; Kinoshita, Yosuke; Wakimoto, Kazuki; Isfahani, Ali Pournaghshband; Song, Qilei; Doitomi, Kazuki; Furukawa, Shuhei; Hirao, Hajime; Kusuda, Hiromu; Kitagawa, Susumu; Sivaniah, Easan

    2017-07-01

    Mixed matrix membranes (MMMs) for gas separation applications have enhanced selectivity when compared with the pure polymer matrix, but are commonly reported with low intrinsic permeability, which has major cost implications for implementation of membrane technologies in large-scale carbon capture projects. High-permeability polymers rarely generate sufficient selectivity for energy-efficient CO2 capture. Here we report substantial selectivity enhancements within high-permeability polymers as a result of the efficient dispersion of amine-functionalized, nanosized metal-organic framework (MOF) additives. The enhancement effects under optimal mixing conditions occur with minimal loss in overall permeability. Nanosizing of the MOF enhances its dispersion within the polymer matrix to minimize non-selective microvoid formation around the particles. Amination of such MOFs increases their interaction with thepolymer matrix, resulting in a measured rigidification and enhanced selectivity of the overall composite. The optimal MOF MMM performance was verified in three different polymer systems, and also over pressure and temperature ranges suitable for carbon capture.

  17. Surface-modified anodic aluminum oxide membrane with hydroxyethyl celluloses as a matrix for bilirubin removal.

    Science.gov (United States)

    Xue, Maoqiang; Ling, Yisheng; Wu, Guisen; Liu, Xin; Ge, Dongtao; Shi, Wei

    2013-01-01

    Microporous anodic aluminum oxide (AAO) membranes were modified by 3-glycidoxypropyltrimethoxysilane to produce terminal epoxy groups. These were used to covalently link hydroxyethyl celluloses (HEC) to amplify reactive groups of AAO membrane. The hydroxyl groups of HEC-AAO composite membrane were further modified with 1,4-butanediol diglycidyl ether to link arginine as an affinity ligand. The contents of HEC and arginine of arginine-immobilized HEC-AAO membrane were 52.1 and 19.7mg/g membrane, respectively. As biomedical adsorbents, the arginine-immobilized HEC-AAO membranes were tested for bilirubin removal. The non-specific bilirubin adsorption on the unmodified HEC-AAO composite membranes was 0.8mg/g membrane. Higher bilirubin adsorption values, up to 52.6mg/g membrane, were obtained with the arginine-immobilized HEC-AAO membranes. Elution of bilirubin showed desorption ratio was up to 85% using 0.3M NaSCN solution as the desorption agent. Comparisons equilibrium and dynamic capacities showed that dynamic capacities were lower than the equilibrium capacities. In addition, the adsorption mechanism of bilirubin and the effects of temperature, initial concentration of bilirubin, albumin concentration and ionic strength on adsorption were also investigated. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix.

    Science.gov (United States)

    Kehlet, Stephanie N; Willumsen, Nicholas; Armbrecht, Gabriele; Dietzel, Roswitha; Brix, Susanne; Henriksen, Kim; Karsdal, Morten A

    2018-01-01

    The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies.

  19. Permeability and Selectivity of PPO/Graphene Composites as Mixed Matrix Membranes for CO2 Capture and Gas Separation

    Directory of Open Access Journals (Sweden)

    Riccardo Rea

    2018-01-01

    Full Text Available We fabricated novel composite (mixed matrix membranes based on a permeable glassy polymer, Poly(2,6-dimethyl-1,4-phenylene oxide (PPO, and variable loadings of few-layer graphene, to test their potential in gas separation and CO2 capture applications. The permeability, selectivity and diffusivity of different gases as a function of graphene loading, from 0.3 to 15 wt %, was measured at 35 and 65 °C. Samples with small loadings of graphene show a higher permeability and He/CO2 selectivity than pure PPO, due to a favorable effect of the nanofillers on the polymer morphology. Higher amounts of graphene lower the permeability of the polymer, due to the prevailing effect of increased tortuosity of the gas molecules in the membrane. Graphene also allows dramatically reducing the increase of permeability with temperature, acting as a “stabilizer” for the polymer matrix. Such effect reduces the temperature-induced loss of size-selectivity for He/N2 and CO2/N2, and enhances the temperature-induced increase of selectivity for He/CO2. The study confirms that, as observed in the case of other graphene-based mixed matrix glassy membranes, the optimal concentration of graphene in the polymer is below 1 wt %. Below such threshold, the morphology of the nanoscopic filler added in solution affects positively the glassy chains packing, enhancing permeability and selectivity, and improving the selectivity of the membrane at increasing temperatures. These results suggest that small additions of graphene to polymers can enhance their permselectivity and stabilize their properties.

  20. Substrate Effect on Carbon/Ceramic Mixed Matrix Membrane Prepared by a Vacuum-Assisted Method for Desalination

    Directory of Open Access Journals (Sweden)

    Yingjun Song

    2018-05-01

    Full Text Available This work investigates the effect of various membrane substrates and coating conditions on the formation of carbon/ceramic mixed matrix membranes for desalination application. The substrates were impregnated with phenolic resin via a vacuum-assisted method followed by carbonization under an inert gas. Substrates with pore sizes of 100 nm required a single impregnation step only, where short vacuum times (<120 s resulted in low quality membranes with defects. For vacuum times of ≥120 s, high quality membranes with homogeneous impregnation were prepared leading to high salt rejection (>90% and high water fluxes (up to 25 L m−2 h−1. The increase in water flux as a function of the vacuum time confirms the vacuum etching effect resulting from the vacuum-assisted method. Substrates with pore sizes of 140 nm required two impregnation steps. These pores were too large for the ceramic inter-particle space to be filled with phenolic resin via a single step. In the second impregnation step, increasing the concentration of the phenolic resin resulted in membranes with lower water fluxes. These results indicate that thicker films were formed by increasing the phenolic resin concentration. In the case of substrates with pores of 600 nm, these pores were too large and inter-particle space filling with phenolic resin was not attained.

  1. Metal Organic Framework Crystals in Mixed-Matrix Membranes: Impact of the Filler Morphology on the Gas Separation Performance.

    Science.gov (United States)

    Sabetghadam, Anahid; Seoane, Beatriz; Keskin, Damla; Duim, Nicole; Rodenas, Tania; Shahid, Salman; Sorribas, Sara; Le Guillouzer, Clément; Clet, Guillaume; Tellez, Carlos; Daturi, Marco; Coronas, Joaquin; Kapteijn, Freek; Gascon, Jorge

    2016-05-10

    Mixed-matrix membranes (MMMs) comprising NH 2 -MIL-53(Al) and Matrimid ® or 6FDA-DAM have been investigated. The MOF loading has been varied between 5 and 20 wt%, while NH 2 -MIL-53(Al) with three different morphologies: nanoparticles, nanorods and microneedles have been dispersed in Matrimid ® . The synthesized membranes have been tested in the separation of CO 2 from CH 4 in an equimolar mixture. At 3 bar and 298 K for 8 wt% MOF loading, incorporation of NH 2 -MIL-53(Al) nanoparticles leads to the largest improvement compared to nanorods and microneedles. The incorporation of the best performing filler, i.e. NH 2 -MIL-53(Al) nanoparticles, to the highly permeable 6FDA-DAM has a larger effect, and the CO 2 permeability increased up to 85 % with slightly lower selectivities for 20 wt% MOF loading. Specifically, these membranes have a permeability of 660 Barrer with CO 2 /CH 4 separation factor of 28, leading to a performance very close to the Robeson limit of 2008. Furthermore, a new non-destructive technique based on Raman spectroscopy mapping is introduced to assess the homogeneity of the filler dispersion in the polymer matrix. The MOF contribution can be calculated by modelling the spectra. The determined homogeneity of the MOF filler distribution in the polymer is confirmed by FIB-SEM analysis.

  2. STRUCTURAL CHARACTERIZATION AND GAS PERMEATION PROPERTIES OF POLYETHERIMIDE (PEI/ZEOLITIC IMIDAZOLATE (ZIF-11 MIXED MATRIX MEMBRANES

    Directory of Open Access Journals (Sweden)

    Mehtap Şafak Boroğlu

    2016-06-01

    Full Text Available In this study, the preparation of polyetherimide (PEI-Ultem1000/ZIF-11 mixed matrix membranes was studied in various ZIF-11 nanoparticles loadings (0, 10, 15, 20, and 30 wt.%. The newly synthesized ZIF-11 nanoparticles with an average particle size of ~280 nm were integrated in PEI membranes as novel mixed matrix membranes (MMMs. The effect of ZIF-11 loading was scrutinised for H2, CO2, and CH4 gas separation performance at 35 °C and 4 bar. The incorporation of ZIF-11 nanoparticles improved the gas permeation properties of the MMMs with an increase in ZIF-11 loading. As the ZIF-11 loading increased up to 20 wt.%, the permeability of H2 and CO2 increased to four times higher than that of the pure polymer. Moderate increase of CH4 permeability was also recorded. At higher loadings above 20 wt.%, the permeability decreased for all gases and the CO2/CH4, and H2/CH4 selectivities increased consistent with the ZIF-11 loading.

  3. Effect of polymer type on characterization and filtration performances of multi-walled carbon nanotubes (MWCNT)-COOH-based polymeric mixed matrix membranes.

    Science.gov (United States)

    Sengur-Tasdemir, Reyhan; Mokkapati, Venkata R S S; Koseoglu-Imer, Derya Y; Koyuncu, Ismail

    2018-05-01

    Multi-walled carbon nanotubes (MWCNTs) can be used for the fabrication of mixed matrix polymeric membranes that can enhance filtration perfomances of the membranes by modifying membrane surface properties. In this study, detailed characterization and filtration performances of MWCNTs functionalized with COOH group, blended into polymeric flat-sheet membranes were investigated using different polymer types. Morphological characterization was carried out using atomic force microscopy, scanning electron microscopy and contact angle measurements. For filtration performance tests, protein, dextran, E. coli suspension, Xanthan Gum and real activated sludge solutions were used. Experimental data and analyses revealed that Polyethersulfone (PES) + MWCNT-COOH mixed matrix membranes have superior performance abilities compared to other tested membranes.

  4. HYDROPHOBIC ZEOLITE-SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER SEPARATION: EFFECT OF ZEOLITE AND SILICONE COMPONENT SELECTION ON PERVAPORATION PERFORMANCE

    Science.gov (United States)

    High-silica ZSM 5 zeolites were incorporated into poly(dimethyl siloxane) (PDMS) polymers to form mixed matrix membranes for ethanol removal from water via pervaporation. Membrane formulation and preparation parameters were varied to determine the effect on pervaporation perform...

  5. Integrating seawater desalination and wastewater reclamation forward osmosis process using thin-film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone support layer.

    Science.gov (United States)

    Choi, Hyeon-Gyu; Son, Moon; Choi, Heechul

    2017-10-01

    Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) support layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant-membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also supported by visualized characterization of fouling layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant-membrane interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Protein translocation channel of mitochondrial inner membrane and matrix-exposed import motor communicate via two-domain coupling protein.

    Science.gov (United States)

    Banerjee, Rupa; Gladkova, Christina; Mapa, Koyeli; Witte, Gregor; Mokranjac, Dejana

    2015-12-29

    The majority of mitochondrial proteins are targeted to mitochondria by N-terminal presequences and use the TIM23 complex for their translocation across the mitochondrial inner membrane. During import, translocation through the channel in the inner membrane is coupled to the ATP-dependent action of an Hsp70-based import motor at the matrix face. How these two processes are coordinated remained unclear. We show here that the two domain structure of Tim44 plays a central role in this process. The N-terminal domain of Tim44 interacts with the components of the import motor, whereas its C-terminal domain interacts with the translocation channel and is in contact with translocating proteins. Our data suggest that the translocation channel and the import motor of the TIM23 complex communicate through rearrangements of the two domains of Tim44 that are stimulated by translocating proteins.

  7. Viability of chondrocytes seeded onto a collagen I/III membrane for matrix-induced autologous chondrocyte implantation.

    Science.gov (United States)

    Hindle, Paul; Hall, Andrew C; Biant, Leela C

    2014-11-01

    Cell viability is crucial for effective cell-based cartilage repair. The aim of this study was to determine the effect of handling the membrane during matrix-induced autologous chondrocyte implantation surgery on the viability of implanted chondrocytes. Images were acquired under five conditions: (i) Pre-operative; (ii) Handled during surgery; (iii) Cut edge; (iv) Thumb pressure applied; (v) Heavily grasped with forceps. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 6.60 × 10(5) cells/cm(2) (5.74-7.11 × 10(5) ) in specimens that did not have significant trauma decreasing significantly in specimens that had been grasped with forceps (p < 0.001) or cut (p = 0.004). Cell viability on delivery grade membrane was 75.1%(72.4-77.8%). This dropped to 67.4%(64.1-69.7%) after handling (p = 0.002), 56.3%(51.5-61.6%) after being thumbed (p < 0.001) and 28.8%(24.7-31.2%) after crushing with forceps (p < 0.001). When cut with scissors there was a band of cell death approximately 275 µm in width where cell viability decreased to 13.7%(10.2-18.2%, p < 0.001). Higher magnification revealed cells without the typical rounded appearance of chondrocytes. We found that confocal laser-scanning microscope (CLSM) can be used to quantify and image the fine morphology of cells on a matrix-induced autologous chondrocyte implantation (MACI) membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Thermo-mechanical properties of mixed-matrix membranes encompassing zeolitic imidazolate framework-90 and polyvinylidine difluoride: ZIF-90/PVDF nanocomposites

    Science.gov (United States)

    Flyagina, Irina S.; Mahdi, E. M.; Titov, Kirill; Tan, Jin-Chong

    2017-08-01

    Mixed-matrix membranes are contemporary nanocomposite materials with many potential applications, from liquid and gas separations to chemical sensors and biomedicine. We report fabrication of a metal-organic framework (MOF)-based nanocomposite, combining polyvinylidene difluoride (PVDF) polymer as the matrix and ZIF-90 nanocrystals of up to 30 wt. % filler content. The focus is to establish the processing—microstructure—mechanical property relationships. We reveal the importance for quantifying salient effects of the filler contents: (i) tensile strength degrades beyond 10 wt. % and (ii) mechanical toughness declines due to membrane embrittlement. These are vital mechanical aspects but widely overlooked in the emergent field of MOF membranes and composites.

  9. Graphene immobilized enzyme/polyethersulfone mixed matrix membrane: Enhanced antibacterial, permeable and mechanical properties

    International Nuclear Information System (INIS)

    Duan, Linlin; Wang, Yuanming; Zhang, Yatao; Liu, Jindun

    2015-01-01

    Graphical abstract: - Highlights: • Lysozyme was immobilized on the surface of graphene oxide (GO) and reduced GO (RGO). • The novel hybrid membranes based on lysozyme and graphene were fabricated firstly. • These membranes showed good antibacterial and mechanical performance. - Abstract: Enzyme immobilization has been developed to address lots of issues of free enzyme, such as instability, low activity and difficult to retain. In this study, graphene was used as an ideal carrier for lysozyme immobilization, including graphene oxide (GO) immobilized lysozyme (GO-Ly) and chemically reduced graphene oxide (CRGO) immobilized lysozyme (CRGO-Ly). Herein, lysozyme as a bio-antibacterial agent has excellent antibacterial performance and the products of its catalysis are safety and nontoxic. Then the immobilized lysozyme materials were blended into polyethersulfone (PES) casting solution to prepare PES ultrafiltration membrane via phase inversion method. GO and CRGO were characterized by Fourier transform infrared spectroscopy (FTIR), Ultraviolet–visible spectrum (UV), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and the immobilized lysozyme composites were observed by fluorescent microscopy. The results revealed that GO and CRGO were successfully synthesized and lysozyme was immobilized on their surfaces. The morphology, hydrophilicity, mechanical properties, separation properties and antibacterial activity of the hybrid membranes were characterized in detail. The hydrophilicity, water flux and mechanical strength of the hybrid membranes were significantly enhanced after adding the immobilized lysozyme. In the antibacterial experiment, the hybrid membranes exhibited an effective antibacterial performance against Escherichia coli (E. coli).

  10. On the direct synthesis of Cu(BDC) MOF nanosheets and their performance in mixed matrix membranes

    Energy Technology Data Exchange (ETDEWEB)

    Shete, Meera; Kumar, Prashant; Bachman, Jonathan E.; Ma, Xiaoli; Smith, Zachary P.; Xu, Wenqian; Mkhoyan, K. Andre; Long, Jeffrey R.; Tsapatsis, Michael

    2018-03-01

    High aspect-ratio nanosheets of metal-organic frameworks (MOFs) hold promise for use as selective flakes in gas separation membranes. However, simple and scalable methods for the synthesis of MOF nanosheets have thus far remained elusive. Here, we describe the direct synthesis of Cu(BDC) (BDC2-= 1,4-benzenedicarboxylate) nanosheets with an average lateral size of 2.5 mu m and a thickness of 25 nm from a well-mixed solution. Characterization of the nanosheets by powder and thin film X-ray diffraction, electron microscopy, and electron diffraction reveals pronounced structural disorder that may affect their pore structure. Incorporation of the Cu (BDC) nanosheets into a Matrimid polymer matrix results in mixed matrix membranes (MMMs) that exhibit a 70% increase in the CO2/CH4 selectivity compared with that of Matrimid. Analysis of new and previously reported permeation data for Cu(BDC) MMMs using a mathematical model for selective flake composites indicates that further performance improvements could be achieved with the selection of different polymers for use in the continuous phase.

  11. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: II. Performance characterization under contaminated feed conditions

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Mixed matrix membranes (MMMs) composed of the crosslinkable polyimide PDMC and surface modified (SM) SSZ-13 have recently been shown to enhance carbon dioxide permeability and carbon dioxide/methane selectivity versus neat PDMC films by as much as 47% and 13%, respectively (Part I). The previous film characterization, however, was performed using ideal, clean mixed gas feeds. In this paper, PDMC/SSZ-13 MMMs are further characterized using more realistic mixed gases containing low concentrations (500 or 1000. ppm) of toluene as a model contaminant. Mixed matrix membranes are shown to outperform pure PDMC films in the presence of toluene with 43% greater carbon dioxide permeability and 12% greater carbon dioxide/selectivity at 35 °C and 700 psia feed pressure. These results suggest that MMMs-in addition to exhibiting enhanced transport properties-may mitigate performance degradation due to antiplasticization effects. Moreover, the analyses presented here show that the reduction in separation performance by trace contaminant-accelerated physical aging can be suppressed greatly with MMMs. © 2011 Elsevier B.V.

  12. A membrane-bound matrix-metalloproteinase from Nicotiana tabacum cv. BY-2 is induced by bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Wahner Verena

    2009-06-01

    Full Text Available Abstract Background Plant matrix metalloproteinases (MMP are conserved proteolytic enzymes found in a wide range of monocotyledonous and dicotyledonous plant species. Acting on the plant extracellular matrix, they play crucial roles in many aspects of plant physiology including growth, development and the response to stresses such as pathogen attack. Results We have identified the first tobacco MMP, designated NtMMP1, and have isolated the corresponding cDNA sequence from the tobacco suspension cell line BY-2. The overall domain structure of NtMMP1 is similar to known MMP sequences, although certain features suggest it may be constitutively active rather than dependent on proteolytic processing. The protein appears to be expressed in two forms with different molecular masses, both of which are enzymatically active as determined by casein zymography. Exchanging the catalytic domain of NtMMP1 with green fluorescent protein (GFP facilitated subcellular localization by confocal laser scanning microscopy, showing the protein is normally inserted into the plasma membrane. The NtMMP1 gene is expressed constitutively at a low level but can be induced by exposure to bacterial pathogens. Conclusion Our biochemical analysis of NtMMP1 together with bioinformatic data on the primary sequence indicate that NtMMP1 is a constitutively-active protease. Given its induction in response to bacterial pathogens and its localization in the plasma membrane, we propose a role in pathogen defense at the cell periphery.

  13. Growth and morphogenesis of embryonic mouse organs on non-coated and extracellular matrix-coated Biopore membrane

    Science.gov (United States)

    Hardman, P.; Klement, B. J.; Spooner, B. S.

    1993-01-01

    Embryonic mouse salivary glands, pancreata, and kidneys were isolated from embryos of appropriate gestational age by microdissection, and were cultured on Biopore membrane either non-coated or coated with type I collagen or Matrigel. As expected, use of Biopore membrane allowed high quality photomicroscopy of the living organs. In all organs extensive mesenchymal spreading was observed in the presence of type I collagen or Matrigel. However, differences were noted in the effects of extracellular matrix (ECM) coatings on epithelial growth and morphogenesis: salivary glands were minimally affected, pancreas morphogenesis was adversely affected, and kidney growth and branching apparently was enhanced. It is suggested that these differences in behaviour reflect differences in the strength of interactions between the mesenchymal cells and their surrounding endogenous matrix, compared to the exogenous ECM macromolecules. This method will be useful for culture of these and other embryonic organs. In particular, culture of kidney rudiments on ECM-coated Biopore offers a great improvement over previously used methods which do not allow morphogenesis to be followed in vitro.

  14. Mixed matrix membranes for process intensification in electrodialysis of amino acids

    NARCIS (Netherlands)

    Kattan Readi, O.M.; Rolevink, Hendrikus H.M.; Nijmeijer, Dorothea C.

    2014-01-01

    BACKGROUND Amino acids are valuable intermediates in the biobased economy for the production of chemicals. Electro-membrane processes combined with enzymatic modification have been investigated as an alternative technology for the fractionation of a mixture of amino acids with almost identical

  15. New low-flux mixed matrix membranes that offer superior removal of protein-bound toxins from human plasma

    Science.gov (United States)

    Pavlenko, Denys; van Geffen, Esmée; van Steenbergen, Mies J.; Glorieux, Griet; Vanholder, Raymond; Gerritsen, Karin G. F.; Stamatialis, Dimitrios

    2016-10-01

    Hemodialysis is a widely available and well-established treatment for patients with End Stage Renal Disease (ESRD). However, although life-sustaining, patient mortality rates are very high. Several recent studies corroborated the link between dialysis patients’ outcomes and elevated levels of protein-bound uremic toxins (PBUT) that are poorly removed by conventional hemodialysis. Therefore, new treatments are needed to improve their removal. Recently, our group showed that the combination of dialysis and adsorption on one membrane, the mixed matrix membrane (MMM), can effectively remove those toxins from human plasma. However, these first MMMs were rather large in diameter and their mass transport characteristics needed improvement before application in the clinical setting. Therefore, in this study we developed a new generation of MMMs that have a smaller diameter and optimized characteristics offering superior ability in removing the PBUT indoxyl sulfate (IS) and p-cresyl sulfate (pCS) in comparison to first generation MMMs (30 and 125% respectively), as well as, a commercial dialysis membrane (more than 100% better removal).

  16. Characterizing fluorescent dissolved organic matter in a membrane bioreactor via excitation-emission matrix combined with parallel factor analysis.

    Science.gov (United States)

    Maqbool, Tahir; Quang, Viet Ly; Cho, Jinwoo; Hur, Jin

    2016-06-01

    In this study, we successfully tracked the dynamic changes in different constitutes of bound extracellular polymeric substances (bEPS), soluble microbial products (SMP), and permeate during the operation of bench scale membrane bioreactors (MBRs) via fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC). Three fluorescent groups were identified, including two protein-like (tryptophan-like C1 and tyrosine-like C2) and one microbial humic-like components (C3). In bEPS, protein-like components were consistently more dominant than C3 during the MBR operation, while their relative abundance in SMP depended on aeration intensities. C1 of bEPS exhibited a linear correlation (R(2)=0.738; pbEPS amounts in sludge, and C2 was closely related to the stability of sludge. The protein-like components were more greatly responsible for membrane fouling. Our study suggests that EEM-PARAFAC can be a promising monitoring tool to provide further insight into process evaluation and membrane fouling during MBR operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Messenger RNA for membrane-type 2 matrix metalloproteinase, MT2-MMP, is expressed in human placenta of first trimester.

    Science.gov (United States)

    Bjørn, S F; Hastrup, N; Larsen, J F; Lund, L R; Pyke, C

    2000-01-01

    An intimately regulated cell surface activation of matrix metalloproteinases (MMPs) is believed to be of critical importance for the control of trophoblast invasion. A histological investigation of the expression and localization of three different MMPs, the membrane-type matrix metalloproteinases 1 and 2 (MT1-MMP, MT2-MMP) and matrix metalloproteinase 2 (MMP-2/gelatinase A) was performed by in situ hybridization on consecutive sections from human placentae of first trimester pregnancies. Cytokeratin immunostaining identified trophoblast cells. Both normal and tubal implantation sites were studied. We observed a high degree of coexpression of MT2-MMP, MT1-MMP and MMP-2 mRNAs in single extravillous cytotrophoblasts that had invaded the endometrium and tubal wall. Furthermore, mRNAs for all three genes were also seen in cytotrophoblasts of cell islands. In contrast to this coexpression pattern, MT2-MMP expression was absent from cell columns and decidual cells, in which signals for MT1-MMP and MMP-2 mRNAs were seen. The present data on the cellular expression of MT2-MMP mRNA in placenta extend our knowledge of the proteolytic events that take place during early pregnancy. The data suggest that MT2-MMP, capable of activating MMP-2 in vitro, is involved in the invasion of extravillous cytotrophoblast, possibly related to the physiological activation of MMP-2. Copyright 2000 Harcourt Publishers Ltd.

  18. Mitochondrial matrix delivery using MITO-Porter, a liposome-based carrier that specifies fusion with mitochondrial membranes

    International Nuclear Information System (INIS)

    Yasuzaki, Yukari; Yamada, Yuma; Harashima, Hideyoshi

    2010-01-01

    Mitochondria are the principal producers of energy in cells of higher organisms. It was recently reported that mutations and defects in mitochondrial DNA (mtDNA) are associated with various mitochondrial diseases including a variety of neurodegenerative and neuromuscular diseases. Therefore, an effective mitochondrial gene therapy and diagnosis would be expected to have great medical benefits. To achieve this, therapeutic agents need to be delivered into the innermost mitochondrial space (mitochondrial matrix), which contains the mtDNA pool. We previously reported on the development of MITO-Porter, a liposome-based carrier that introduces macromolecular cargos into mitochondria via membrane fusion. In this study, we provide a demonstration of mitochondrial matrix delivery and the visualization of mitochondrial genes (mtDNA) in living cells using the MITO-Porter. We first prepared MITO-Porter containing encapsulated propidium iodide (PI), a fluorescent dye used to stain nucleic acids to detect mtDNA. We then confirmed the emission of red-fluorescence from PI by conjugation with mtDNA, when the carriers were incubated in the presence of isolated rat liver mitochondria. Finally, intracellular observation by confocal laser scanning microscopy clearly verified that the MITO-Porter delivered PI to the mitochondrial matrix.

  19. Gas transport properties of novel mixed matrix membranes made of titanate nanotubes and PBI or PPO

    Czech Academy of Sciences Publication Activity Database

    Giel, Verena; Galajdová, Barbora; Popelková, Daniela; Kredatusová, Jana; Trchová, Miroslava; Pavlova, Ewa; Beneš, Hynek; Válek, R.; Peter, Jakub

    2015-01-01

    Roč. 56, č. 12 (2015), s. 3285-3293 ISSN 1944-3994. [International Conference on Membrane and Electromembrane Processes - MELPRO 2014. Prague, 18.05.2014-21.05.2014] R&D Projects: GA ČR(CZ) GPP106/12/P643 Institutional support: RVO:61389013 Keywords : polybenzimidazole * poly(phenylene oxide) * titanate nanotubes Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.272, year: 2015

  20. Type 1 Diabetes and Sleep

    OpenAIRE

    Farabi, Sarah S.

    2016-01-01

    IN BRIEF In people with type 1 diabetes, sleep may be disrupted as a result of both behavioral and physiological aspects of diabetes and its management. This sleep disruption may negatively affect disease progression and development of complications. This review highlights key research findings regarding sleep in people with type 1 diabetes.

  1. LIM kinase1 modulates function of membrane type matrix metalloproteinase 1: implication in invasion of prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Chakrabarti Ratna

    2011-01-01

    Full Text Available Abstract Background LIM kinase 1 (LIMK1 is an actin and microtubule cytoskeleton modulatory protein that is overexpressed in a number of cancerous tissues and cells and also promotes invasion and metastasis of prostate and breast cancer cells. Membrane type matrix metalloproteinase 1 (MT1-MMP is a critical modulator of extracellular matrix (ECM turnover through pericellular proteolysis and thus plays crucial roles in neoplastic cell invasion and metastasis. MT1-MMP and its substrates pro-MMP-2 and pro-MMP-9 are often overexpressed in a variety of cancers including prostate cancer and the expression levels correlate with the grade of malignancy in prostate cancer cells. The purpose of this study is to determine any functional relation between LIMK1 and MT1-MMP and its implication in cell invasion. Results Our results showed that treatment with the hydroxamate inhibitor of MT1-MMP, MMP-2 and MMP-9 ilomastat inhibited LIMK1-induced invasion of benign prostate epithelial cells. Over expression of LIMK1 resulted in increased collagenolytic activity of MMP-2, and secretion of pro-MMP2 and pro-MMP-9. Cells over expressing LIMK1 also exhibited increased expression of MT1-MMP, transcriptional activation and its localization to the plasma membrane. LIMK1 physically associates with MT1-MMP and is colocalized with it to the Golgi vesicles. We also noted increased expression of both MT1-MMP and LIMK1 in prostate tumor tissues. Conclusion Our results provide new information on regulation of MT1-MMP function by LIMK1 and showed for the first time, involvement of MMPs in LIMK1 induced cell invasion.

  2. The Force Exerted by the Membrane Potential During Protein Import into the Mitochondrial Matrix

    Science.gov (United States)

    Shariff, Karim; Ghosal, Sandip; Matouschek, Andreas

    2002-01-01

    The electrostatic force exerted on a targeting sequence by the electrical potential across the inner mitochondrial membrane is calculated and found to vary from 1.4 pN to 2.2 pN (per unit elementary charge) as the radius of the inner membrane pore (assumed aqueous) is varied from 12 to 6.5 Angstroms, its measured range. Since the pore is not very much wider than the distance between water molecules, the full shielding effect of water may not be present; the extreme case of a nonaqueous pore gives a force of 3.1 pN per unit charge, which represents an upper limit. When applied to mitochondrial import experiments on the protein harness, these results imply that a force of 11 plus or minus 4 pN is sufficient to catalyze the unfolding of harness during import. Comparison of these results with unfolding forces measured using atomic force microscopy suggests that the two are not inconsistent.

  3. Construction and characterization of human oral mucosa equivalent using hyper-dry amniotic membrane as a matrix.

    Science.gov (United States)

    Qi, Fangfang; Yoshida, Toshiko; Koike, Takeshi; Aizawa, Hitoshi; Shimane, Tetsu; Li, Yinghui; Yamada, Shinichi; Okabe, Motonori; Nikaido, Toshio; Kurita, Hiroshi

    2016-05-01

    Human amniotic membrane(HAM) as a graft material has been used in various fields. Hyper-dry amniotic membrane (HD-AM) is a novel dried amniotic membrane that is easy to handle and can be preserved at room temperature without time limitation. The purpose of this study was to investigate the useful properties of HD-AM in reconstruction of the oral mucosa. Human oral keratinocytes were isolated and seeded on HD-AM in serum-free culture system. Oral mucosa equivalent (OME) was developed and transplanted onto full-thickness wound on athymic mice. The wound healing was analyzed and the OME both before and after transplantation was analyzed with hematoxylin-eosin staining and immunohistochemical staining for Cytokines 10 (CK10), Cytokines 16 (CK16), and Ivolucrin (IVL). Oral keratinocytes spread and proliferated well on HD-AM. Two weeks after air-lifting, OME had formed with good differentiation and morphology. We confirmed immunohistochemically that the expression of CK10 was positive in all suprabasal layers, as was CK16 in the upper layers, while IVL was present in all cell layers. Three weeks after transplantation to athymic mice, the newly generated tissue had survived well with the smallest contraction. The epithelial cells of newly generated tissue expressed CK10 throughout in all suprabasal layers, IVL was mainly in the granular layer, and CK16 positive cells were observed in all spinous layer and granular layer but were not expressed in the mouse skin, all of which were similar to native gingival mucosa. The OME with HD-AM as a matrix revealed a good morphology and stable wound healing. This study demonstrates that HD-AM is a useful and feasible biomaterial for oral mucosa reconstruction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Comparative Study of MIL-96(Al) as Continuous Metal-Organic Frameworks Layer and Mixed-Matrix Membrane.

    Science.gov (United States)

    Knebel, Alexander; Friebe, Sebastian; Bigall, Nadja Carola; Benzaqui, Marvin; Serre, Christian; Caro, Jürgen

    2016-03-23

    MIL-96(Al) layers were prepared as supported metal-organic frameworks membrane via reactive seeding using the α-alumina support as the Al source for the formation of the MIL-96(Al) seeds. Depending on the solvent mixture employed during seed formation, two different crystal morphologies, with different orientation of the transport-active channels, have been formed. This crystal orientation and habit is predefined by the seed crystals and is kept in the subsequent growth of the seeds to continuous layers. In the gas separation of an equimolar H2/CO2 mixture, the hydrogen permeability of the two supported MIL-96(Al) layers was found to be highly dependent on the crystal morphology and the accompanied channel orientation in the layer. In addition to the neat supported MIL-96(Al) membrane layers, mixed-matrix membranes (MMMs, 10 wt % filler loading) as a composite of MIL-96(Al) particles as filler in a continuous Matrimid polymer phase have been prepared. Five particle sizes of MIL-96(Al) between 3.2 μm and 55 nm were synthesized. In the preparation of the MIL-96(Al)/Matrimid MMM (10 wt % filler loading), the following preparation problems have been identified: The bigger micrometer-sized MIL-96(Al) crystals show a trend toward sedimentation during casting of the MMM, whereas for nanoparticles aggregation and recrystallization to micrometer-sized MIL-96(Al) crystals has been observed. Because of these preparation problems for MMM, the neat supported MIL-96(Al) layers show a relatively high H2/CO2 selectivity (≈9) and a hydrogen permeance approximately 2 magnitudes higher than that of the best MMM.

  5. Study of the relationship between mononuclear inflammatory infiltrate and Ki-67 and basement membrane and extracellular matrix protein expression in radicular cysts.

    Science.gov (United States)

    Mourão, R V C; Júnior, E C Pinheiro; Barros Silva, P G; Turatti, E; Mota, M R L; Alves, A P N N

    2016-05-01

    To evaluate the relationship between mononuclear inflammatory infiltrate and the expression of a proliferative immunomarker (Ki-67) as well as to evaluate basement membrane and extracellular matrix proteins (laminin and collagen type IV) in radicular cysts and dentigerous cysts (DC). Immunohistochemical analyses were performed in heavily inflamed radicular cysts (HIRC), slightly inflamed radicular cysts (SIRC) and DC (n = 20) using Ki-67 (Dako(®) , 1 : 50), anticollagen type IV (DBS(®) , 1 : 40) and antilaminin (DBS(®) , 1 : 20). The data were analysed using anova/Tukey's test (Ki-67) and Kruskal-Wallis/Dunn's test (collagen type IV and laminin) (P collagen type IV in the basement membrane of the SIRC group was significantly more continuous (P = 0.0475) than in the HIRC group. DC had significantly less collagen type IV in extracellular matrix immunoexpression than HIRC and SIRC (P = 0.0246). Laminin was absent in the basement membrane in the SIRC and DC groups, and the extracellular matrix of the HIRC was weak and punctate. The presence of inflammatory factors in the radicular cyst wall modified the expression of proliferation factors in the epithelial lining and the expression of collagen type IV and laminin in the basement membrane, but did not modify extracellular matrix behaviour in radicular cysts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  6. Thermo-mechanical properties of mixed-matrix membranes encompassing zeolitic imidazolate framework-90 and polyvinylidine difluoride: ZIF-90/PVDF nanocomposites

    Directory of Open Access Journals (Sweden)

    Irina S. Flyagina

    2017-08-01

    Full Text Available Mixed-matrix membranes are contemporary nanocomposite materials with many potential applications, from liquid and gas separations to chemical sensors and biomedicine. We report fabrication of a metal-organic framework (MOF-based nanocomposite, combining polyvinylidene difluoride (PVDF polymer as the matrix and ZIF-90 nanocrystals of up to 30 wt. % filler content. The focus is to establish the processing—microstructure—mechanical property relationships. We reveal the importance for quantifying salient effects of the filler contents: (i tensile strength degrades beyond 10 wt. % and (ii mechanical toughness declines due to membrane embrittlement. These are vital mechanical aspects but widely overlooked in the emergent field of MOF membranes and composites.

  7. Expression of matrix metalloproteinase genes during basement membrane degradation in the metamorphosis of Bombyx mori.

    Science.gov (United States)

    Kawasaki, Hideki; Manickam, Asaithambi; Shahin, Rima; Ote, Manabu; Iwanaga, Masashi

    2018-01-05

    The present study was conducted to clarify the involvement of the basement membrane (BM) in insect metamorphosis through analysis of the expression profile of two types of metalloproteinase (MMP and ADAMTS) genes in several organs, their ecdysone involvement, and the histological change of BM. BM was observed around wing sac and in the wing cavity and around fat bodies at the W0 stage but disappeared after the W3 stage, and wing discs evaginated and fat body cells scattered after the W3 stage. The disappearance of the BM of midgut and silk glands was not observed after the W3 stage, but degenerated epithelium cells in the midgut and shrunken cells in the silk gland were observed after the W3 stage. BmMMP1 showed a peak at P0 in the wing discs, fat bodies, midgut, and silk gland. BmMMP2 showed a broad peak around pupation in the wing discs, fat bodies, midgut, and silk gland. BmADAMTS-1 showed enhanced expression at W2 in the wing discs, fat bodies, midgut, and hemocyte, while BmADAMTS-L showed enhanced expression at W3 in the fat bodies, midgut, silk gland, and hemocyte. After pupation, they showed a different expression in different organs. All of four genes were induced by 20-hydroxyecdysone in wing discs in vitro. The present results suggested the involvement of MMPs and ADAMTS in the BM digestion and the morphogenesis of organs during Bombyx metamorphosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A Mixed Matrix Membrane of Poly (4-methyl-1-pentyne Filled with MIL 53 Particles and Its Application in Carbon Dioxide and Nitrogen Separation

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2016-05-01

    Full Text Available The performance of poly (4-metyl-1-pentyne as mixed matrix membrane (MMM mixed with MIL 53 particles was studied to separate mixtures of carbon dioxide and nitrogen. MIL 53 particles was added to the polymer matrix with 10, 20 and 30 weight percentages. The adsorption of CO2 and N2 gases by MIL 53 was evaluated and the adsorption data was analyzed by Langmuir equation. Structure and thermal/mechanical properties of prepared membranes were characterized by means of FTIR, SEM, TGA and elongation test. Moreover, the gas permeation properties of membranes were studied by measuring the permeation of pure CO2 and N2. Furthermore, for accurate understanding of the gas permeation properties of the membranes, diffusion and solution coefficient of gases in neat membrane and MMMs were calculated using modified time-lag method. The results from TGA analysis showed that the degradation temperature of MMMs was enhanced and increased to 348ºC for membrane containing 30 wt% of MIL 53. The SEM images also illustrated a relatively uniform dispersion of particles with proper polymer/filler interfaces in the polymer matrix. The gas permeation results revealed that the permeability of both gases (especially CO2 increased with increasing MIL 53 loading, in which the permeability of CO2 increased from 98.74 Barrer in neat membrane to 217.65 Barrer in MMM containing 30 wt% filler. Moreover, calculation of CO2/N2 selectivity depicted that the selectivity enhanced from 16.66 to 22.70. Finally, the performance of MMMs was compared with Robeson’s upper bound in CO2/N2 separation and results showed that the MMM having 30 wt% of MIL 53 took over the Robeson bound.

  9. Matrigel Basement Membrane Matrix influences expression of microRNAs in cancer cell lines

    International Nuclear Information System (INIS)

    Price, Karina J.; Tsykin, Anna; Giles, Keith M.; Sladic, Rosemary T.; Epis, Michael R.; Ganss, Ruth; Goodall, Gregory J.; Leedman, Peter J.

    2012-01-01

    Highlights: ► Matrigel alters cancer cell line miRNA expression relative to culture on plastic. ► Many identified Matrigel-regulated miRNAs are implicated in cancer. ► miR-1290, -210, -32 and -29b represent a Matrigel-induced miRNA signature. ► miR-32 down-regulates Integrin alpha 5 (ITGA5) mRNA. -- Abstract: Matrigel is a medium rich in extracellular matrix (ECM) components used for three-dimensional cell culture and is known to alter cellular phenotypes and gene expression. microRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and have roles in cancer. While miRNA profiles of numerous cell lines cultured on plastic have been reported, the influence of Matrigel-based culture on cancer cell miRNA expression is largely unknown. This study investigated the influence of Matrigel on the expression of miRNAs that might facilitate ECM-associated cancer cell growth. We performed miRNA profiling by microarray using two colon cancer cell lines (SW480 and SW620), identifying significant differential expression of miRNAs between cells cultured in Matrigel and on plastic. Many of these miRNAs have previously been implicated in cancer-related processes. A common Matrigel-induced miRNA signature comprised of up-regulated miR-1290 and miR-210 and down-regulated miR-29b and miR-32 was identified using RT-qPCR across five epithelial cancer cell lines (SW480, SW620, HT-29, A549 and MDA-MB-231). Experimental modulation of these miRNAs altered expression of their known target mRNAs involved in cell adhesion, proliferation and invasion, in colon cancer cell lines. Furthermore, ITGA5 was identified as a novel putative target of miR-32 that may facilitate cancer cell interactions with the ECM. We propose that culture of cancer cell lines in Matrigel more accurately recapitulates miRNA expression and function in cancer than culture on plastic and thus is a valuable approach to the in vitro study of miRNAs.

  10. Higher Dialysate Matrix Metalloproteinase-2 Levels Are Associated with Peritoneal Membrane Dysfunction

    Science.gov (United States)

    Cho, Yeoungjee; Johnson, David W.; Vesey, David A.; Hawley, Carmel M.; Pascoe, Elaine M.; Clarke, Margaret; Topley, Nicholas

    2016-01-01

    ♦ Background: Peritoneal dialysis (PD) patients develop progressive and cumulative peritoneal injury with longer time spent on PD. The present study aimed to a) describe the trend of peritoneal injury biomarkers, matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1), in incident PD patients, b) to explore the capacity of dialysate MMP-2 to predict peritoneal solute transport rate (PSTR) and peritonitis, and c) to evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solution on these outcomes. ♦ Methods: The study included 178 participants from the balANZ trial who had at least 1 stored dialysate sample. Changes in PSTR and peritonitis were primary outcome measures, and the utility of MMP-2 in predicting these outcomes was analyzed using multilevel linear regression and multilevel Poisson regression, respectively. ♦ Results: Significant linear increases in dialysate MMP-2 and TIMP-1 concentrations were observed (p < 0.001), but neither was affected by the type of PD solutions received (MMP-2: p = 0.07; TIMP-1: p = 0.63). An increase in PSTR from baseline was associated with higher levels of MMP-2 (p = 0.02), and the use of standard solutions over longer PD duration (p = 0.001). The risk of peritonitis was independently predicted by higher dialysate MMP-2 levels (incidence rate ratio [IRR] per ng/mL 1.01, 95% confidence interval [CI] 1.005 – 1.02, p = 0.002) and use of standard solutions (Biocompatible solution: IRR 0.45, 95% CI 0.24 – 0.85, p = 0.01). ♦ Conclusion: Dialysate MMP-2 and TIMP-1 concentrations increased with longer PD duration. Higher MMP-2 levels were associated with faster PSTR and future peritonitis risk. Administration of biocompatible solutions exerted no significant effect on dialysate levels of MMP-2 or TIMP-1, but did counteract the increase in PSTR and the risk of peritonitis associated with the use of standard PD solutions. This is the first longitudinal study to examine

  11. Polymeric matrix membrane sensors for stability-indicating potentiometric determination of oxybutynin hydrochloride and flavoxate hydrochloride urogenital system drugs.

    Science.gov (United States)

    Heba, Mohamed; Ramadan, Nesrin; El-Laithy, Moustafa

    2008-01-01

    Four polyvinyl chloride (PVC) matrix membrane electrodes responsive to 2 drugs affecting the urogenital system--oxybutynin hydrochloride (OX) and flavoxate hydrochloride (FX)--were developed, described, and characterized. A precipitation-based technique with tungstophosphate (TP) and ammonium reineckate (R) anions as electroactive materials in a PVC matrix with an OX cation was used for electrode 1 and 2 fabrication, respectively. Electrode 3 and 4 fabrication was based on use of the precipitation technique of FX cation with tetrakis (4-chlorophenyl) borate and R anions as electroactive materials. Fast and stable Nernstian responses in the range 1 x 10(-2)-1 x 10(-6) M for the 2 drugs over the pH range 5-8 revealed the performance characteristics of these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was applied to FX and OX in their pharmaceutical formulations and in human plasma samples. The 4 proposed sensors were found to be specific for the drugs in the presence of up to 60% of their degradation products. Validation of the method according to the quality assurance standards showed suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for determination of the drugs by the 4 proposed selective electrodes were 99.5 +/- 0.5, 100.0 +/- 0.4, 99.9 +/- 0.4, and 100.1 +/- 0.4% for sensors 1-4, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was done, and no significant difference found.

  12. Reconstructing the microstructure of polyimide-silicalite mixed-matrix membranes and their particle connectivity using FIB-SEM tomography.

    Science.gov (United States)

    Diblíková, P; Veselý, M; Sysel, P; Čapek, P

    2018-03-01

    Properties of a composite material made of a continuous matrix and particles often depend on microscopic details, such as contacts between particles. Focusing on processing raw focused-ion beam scanning electron microscope (FIB-SEM) tomography data, we reconstructed three mixed-matrix membrane samples made of 6FDA-ODA polyimide and silicalite-1 particles. In the first step of image processing, backscattered electron (BSE) and secondary electron (SE) signals were mixed in a ratio that was expected to obtain a segmented 3D image with a realistic volume fraction of silicalite-1. Second, after spatial alignment of the stacked FIB-SEM data, the 3D image was smoothed using adaptive median and anisotropic nonlinear diffusion filters. Third, the image was segmented using the power watershed method coupled with a seeding algorithm based on geodesic reconstruction from the markers. If the resulting volume fraction did not match the target value quantified by chemical analysis of the sample, the BSE and SE signals were mixed in another ratio and the procedure was repeated until the target volume fraction was achieved. Otherwise, the segmented 3D image (replica) was accepted and its microstructure was thoroughly characterized with special attention paid to connectivity of the silicalite phase. In terms of the phase connectivity, Monte Carlo simulations based on the pure-phase permeability values enabled us to calculate the effective permeability tensor, the main diagonal elements of which were compared with the experimental permeability. In line with the hypothesis proposed in our recent paper (Čapek, P. et al. (2014) Comput. Mater. Sci. 89, 142-156), the results confirmed that the existence of particle clusters was a key microstructural feature determining effective permeability. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  13. Living with Type 1 Diabetes

    Science.gov (United States)

    ... elements: blood glucose control and insulin management, exercise, nutrition and support. Medication A diagnosis of type 1 diabetes means ... crucial part of your daily routine. Learn more: Nutrition How foods ... meal plans Support Emotional support, while not often initially considered, plays ...

  14. Mixed-Matrix Membranes for CO2 and H2 Gas Separations Using Metal-Organic Framework and Mesoporus Hybrid Silicas

    International Nuclear Information System (INIS)

    Musselman, Inga; Balkus, Kenneth Jr.; Ferraris, John

    2009-01-01

    In this work, we have investigated the separation performance of polymer-based mixed-matrix membranes containing metal-organic frameworks and mesoporous hybrid silicas. The MOF/Matrimid(reg s ign) and MOP-18/Matrimid(reg s ign) membranes exhibited improved dispersion and mechanical strength that allowed high additive loadings with reduced aggregation, as is the case of the 80 wt% MOP-18/Matrimid(reg s ign) and the 80% (w/w) Cu-MOF/Matrimid(reg s ign) membranes. Membranes with up to 60% (w/w) ZIF-8 content exhibited similar mechanical strength and improved dispersion. The H 2 /CO 2 separation properties of MOF/Matrimid(reg s ign) mixed-matrix membranes was improved by either keeping the selectivity constant and increasing the permeability (MOF-5, Cu-MOF) or by improving both selectivity and permeability (ZIF-8). In the case of MOF-5/Matrimid(reg s ign) mixed-matrix membranes, the H 2 /CO 2 selectivity was kept at 2.6 and the H 2 permeability increased from 24.4 to 53.8 Barrers. For the Cu-MOF/Matrimid(reg s ign) mixed-matrix membranes, the H 2 /CO 2 selectivity was kept at 2.05 and the H 2 permeability increased from 17.1 to 158 Barrers. These two materials introduced porosity and uniform paths that enhanced the gas transport in the membranes. When ZIF-8/Matrimid(reg s ign) mixed-matrix membranes were studied, the H 2 /CO 2 selectivity increased from 2.9 to 4.4 and the permeability of H 2 increased from 26.5 to 35.8 Barrers. The increased H 2 /CO 2 selectivity in ZIF-8/Matrimid(reg s ign) membranes was explained by the sieving effect introduced by the ZIF-8 crystals (pore window 0.34 nm) that restricted the transport of molecules larger than H 2 . Materials with microporous and/or mesoporous cavities like carbon aerogel composites with zeolite A and zeolite Y, and membranes containing mesoporous ZSM-5 showed sieving effects for small molecules (e.g. H 2 and CO 2 ), however, the membranes were most selective for CO 2 due to the strong interaction of the zeolites with

  15. Stepwise observation and quantification and mixed matrix membrane separation of CO2 within a hydroxy-decorated porous host.

    Science.gov (United States)

    Morris, Christopher G; Jacques, Nicholas M; Godfrey, Harry G W; Mitra, Tamoghna; Fritsch, Detlev; Lu, Zhenzhong; Murray, Claire A; Potter, Jonathan; Cobb, Tom M; Yuan, Fajin; Tang, Chiu C; Yang, Sihai; Schröder, Martin

    2017-04-01

    The identification of preferred binding domains within a host structure provides important insights into the function of materials. State-of-the-art reports mostly focus on crystallographic studies of empty and single component guest-loaded host structures to determine the location of guests. However, measurements of material properties ( e.g. , adsorption and breakthrough of substrates) are usually performed for a wide range of pressure (guest coverage) and/or using multi-component gas mixtures. Here we report the development of a multifunctional gas dosing system for use in X-ray powder diffraction studies on Beamline I11 at Diamond Light Source. This facility is fully automated and enables in situ crystallographic studies of host structures under (i) unlimited target gas loadings and (ii) loading of multi-component gas mixtures. A proof-of-concept study was conducted on a hydroxyl-decorated porous material MFM-300(V III ) under (i) five different CO 2 pressures covering the isotherm range and (ii) the loading of equimolar mixtures of CO 2 /N 2 . The study has successfully captured the structural dynamics underpinning CO 2 uptake as a function of surface coverage. Moreover, MFM-300(V III ) was incorporated in a mixed matrix membrane (MMM) with PIM-1 in order to evaluate the CO 2 /N 2 separation potential of this material. Gas permeation measurements on the MMM show a great improvement over the bare PIM-1 polymer for CO 2 /N 2 separation based on the ideal selectivity.

  16. Prion Fragment Peptides Are Digested with Membrane Type Matrix Metalloproteinases and Acquire Enzyme Resistance through Cu2+-Binding

    Directory of Open Access Journals (Sweden)

    Aya Kojima

    2014-05-01

    Full Text Available Prions are the cause of neurodegenerative disease in humans and other mammals. The structural conversion of the prion protein (PrP from a normal cellular protein (PrPC to a protease-resistant isoform (PrPSc is thought to relate to Cu2+ binding to histidine residues. In this study, we focused on the membrane-type matrix metalloproteinases (MT-MMPs such as MT1-MMP and MT3-MMP, which are expressed in the brain as PrPC-degrading proteases. We synthesized 21 prion fragment peptides. Each purified peptide was individually incubated with recombinant MT1-MMP or MT3-MMP in the presence or absence of Cu2+ and the cleavage sites determined by LC-ESI-MS analysis. Recombinant MMP-7 and human serum (HS were also tested as control. hPrP61-90, from the octapeptide-repeat region, was cleaved by HS but not by the MMPs tested here. On the other hand, hPrP92-168 from the central region was cleaved by MT1-MMP and MT3-MMP at various sites. These cleavages were inhibited by treatment with Cu2+. The C-terminal peptides had higher resistance than the central region. The data obtained from this study suggest that MT-MMPs expressed in the brain might possess PrPC-degrading activity.

  17. Crosslinkable mixed matrix membranes with surface modified molecular sieves for natural gas purification: I. Preparation and experimental results

    KAUST Repository

    Ward, Jason K.

    2011-07-01

    Dense film mixed matrix membranes (MMMs) comprised of SSZ-13 dispersed in a crosslinkable polyimide (PDMC) were fabricated and evaluated for carbon dioxide/methane separations. MMMs containing 25% (w/w) as-received (AR) SSZ-13 exhibited a carbon dioxide permeability of 153 Barrers with a carbon dioxide/methane ideal selectivity of 34.7 at 65. psia and 35 °C. This represents a permeability enhancement of 129% and a decline in selectivity of 4.7% over neat PDMC (PCO2=66.9 Barrers, αCO2/CH4=36.4). A sieve surface modification procedure was developed with the aim of improving SSZ-13/PDMC MMM transport properties. MMMs containing 25% (w/w) surface modified (SM) SSZ-13 exhibited a carbon dioxide permeability of 148 Barrers and carbon dioxide/methane selectivity of 38.9 at 65. psia and 35 °C, representing enhancements in both permeability and selectivity of 121% and 6.9%, respectively. Mixed gas permeation analyses of MMMs containing SM-SSZ-13 using a 10% carbon dioxide/90% methane mixture shows that permeability and selectivity enhancements of 47% and 13%, respectively, over neat PDMC are possible at 700. psia and 35 °C. © 2011 Elsevier B.V.

  18. A Comparison on Gas Separation between PES(polyethersulfone)/MMT (Na-montmorillonite) and PES/TiO2 Mixed Matrix Membranes

    Czech Academy of Sciences Publication Activity Database

    Liang, Ch.-Y.; Uchytil, Petr; Petričkovič, Roman; Lai, Y.-Ch.; Friess, K.; Šípek, M.; Reddy, M.M.; Suen, S.-Y.

    2012-01-01

    Roč. 92, MAY 18 (2012), s. 57-63 ISSN 1383-5866 R&D Projects: GA ČR GCP106/10/J038 Grant - others:NSCT(TW) NSC:99-2911-I-005-002; NSCT(TW) NSC:99-2923-E-005-001-MY2 Institutional research plan: CEZ:AV0Z40720504 Keywords : mixed matrix membrane * polyethersulfone membrane * sodium montmorillonite Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.894, year: 2012

  19. Prepare and characterization of nanocomposite - mixed matrix membranes based on polycarbonate; Preparo e caracterizacao de membranas polimericas de matriz mista nanocomposito baseadas em policarbonato

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Caio M; Pessan, Luiz A., E-mail: caiomp.dema@gmail.co [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais. Lab. de Permeacao e Sorcao; Gomes, Ana C. de O. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas

    2009-07-01

    Mixed matrix membranes based on polycarbonate with different content of sepiolite were prepared by casting. The obtained membranes were characterized by wide-angle X-ray diffraction, thermal analysis, optical transparency and permeation to oxygen. The presence of sepiolite leads to the formation of a polymer-clay interface. The presence of the interface causes the increase in O{sub 2} permeation. Increasing content of sepiolite results in aggregates of sepiolite, which forms preferential channels to the O{sub 2} molecules. This fact is directly related to the strong increasing observed in O{sub 2} permeability. (author)

  20. Barn og diabetes type 1

    OpenAIRE

    Ramstad, Marte Elise; Sagbakken, Sina Bekkelund

    2017-01-01

    Bacheloroppgave sykepleie, 2017 Bakgrunn: Vi har valgt denne problemstillingen fordi diabetes type 1 er svært utbredt hos barn i Norge. Videre har vi lite erfaringer med barn og ønsket å lære mer om denne pasientgruppen. Vi ønsket videre å se på hvordan vi kan undervise og veilede for å gi god og hensiktsmessig sykepleie til barn og deres familier. Hensikt: Finne ut hvordan sykepleier kan fremme egenomsorg hos barn med diabetes gjennom veiledning og undervisning. Dette er noe som sykepl...

  1. Study on physical and electrostatic interactions of counterions in poly(perfluorosulfonic) acid matrix: Characterization of diffusion properties of membrane using radiotracers

    International Nuclear Information System (INIS)

    Suresh, G.; Sodaye, Suparna; Scindia, Y.M.; Pandey, A.K.; Goswami, A.

    2007-01-01

    The self-diffusion coefficients of water and ions were used to study the physical (tortuosity) and electrostatic interactions of counterions in poly(perfluorosulfonic) acid membrane (Nafion-117) matrix. The self-diffusion coefficients of water (D H 2 O m ) were measured in the water swollen Nafion-117 membrane with Zn 2+ , Ca 2+ , Sr 2+ , and Fe 2+ counterions by analyzing the experimental exchange rates between tritium tagged water (HTO) in membrane and equilibrating water. In order to study the effects of equilibrating solution, the HTO-desorption rate profiles between the membrane samples in H + or Cs + forms and equilibrating solution containing CsCl or HCl (0.25mol/L) were measured. It was observed that the HTO-exchange rate profile was slower in case of membrane sample in Cs + -from equilibrated with salt/acid solution than that equilibrated with deionized water in same ionic form. However, HTO-exchange rate profile did not alter in case of H + -form of membrane on equilibration with salt or acid solution. The variation of lnD H 2 O m with polymer volume function V p /(1-V p ), where V p is polymer volume fraction, indicated that: (i) D H 2 O m in the membrane with multivalent counterions was lower than that reported for membrane with monovalent counterions at same V p , and (ii) the linear trends observed in variation of lnD H 2 O m with V p /(1-V p ) for multivalent and monovalent counterions were significantly different. The values of D H 2 O m in membrane normalized with D H 2 O m at V p =0 were taken as an estimate of the tortuosity factor for self-diffusion of ions in the membrane matrix. The self-diffusion coefficients of ions reported in the literature along with tortuosity factor obtained from D H 2 O m in the corresponding ionic forms of the membrane were analyzed to obtain the charge (Z i ) independent electrostatic interaction parameter g(φ) of monovalent and divalent ions in the membrane. This analysis indicated that g(φ) also vary

  2. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis12

    Science.gov (United States)

    Huang, Chi-Hung; Yang, Wen-Hao; Chang, Shyue-Yih; Tai, Shyh-Kuan; Tzeng, Cheng-Hwei; Kao, Jung-Yie; Wu, Kou-Juey; Yang, Muh-Hwa

    2009-01-01

    The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT), and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP) is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis. PMID:20019845

  3. Mesoporous Silica Gel–Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler

    Science.gov (United States)

    Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y.; Huo, Fengwei

    2015-01-01

    The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4–30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores. PMID:26592565

  4. Mesoporous Silica Gel-Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler.

    Science.gov (United States)

    Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y; Huo, Fengwei

    2015-11-23

    The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4-30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores.

  5. What causes type 1 diabetes?

    DEFF Research Database (Denmark)

    Buschard, Karsten

    2011-01-01

    To study type 1 diabetes (T1D), excellent animal models exist, both spontaneously diabetic and virus-induced. Based on knowledge from these, this review focuses on the environmental factors leading to T1D, concentrated into four areas which are: (1) The thymus-dependent immune system: T1D is a T...... T cell reaction and less autoimmunity. Glycolipids presented by CD1 molecules are central in this stimulation. (4) Importance of the intestine and gliadin intake: Gluten-free diet dramatically inhibits T1D in animal models, and epidemiological data are supportive of such an effect in humans....... The mechanisms include less subclinical intestinal inflammation and permeability, and changed composition of bacterial flora, which can also be obtained by intake of probiotics. Gluten-free diet is difficult to implement, and short-term intake has no effect. Regarding the onset of the T1D disease process, slow...

  6. Mixed-Matrix Membranes containing an Azine-Linked Covalent Organic Framework: Influence of the polymeric matrix on Post-Combustion CO 2 -capture

    KAUST Repository

    Shan, Meixia; Seoane, Beatriz; Andres-Garcia, Eduardo; Kapteijn, Freek; Gascon, Jorge

    2017-01-01

    with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO2/N2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While

  7. Matrimid®/polysulfone blend mixed matrix membranes containing ZIF-8 nanoparticles for high pressure stability in natural gas separation

    NARCIS (Netherlands)

    Shahid, S.; Nijmeijer, K.

    2017-01-01

    Plasticization is of important concern in high pressure natural gas separation. Majority of the pure polymers and MOF-MMM systems suffer from plasticization at low pressures. Combination of polymer blending and MMM approach could lead to plasticization resistant membranes with improved membrane

  8. Evidence for the existence of multiple heparan sulfate proteoglycans in the human glomerular basement membrane and mesangial matrix

    NARCIS (Netherlands)

    Groffen, Alexander J A; Hop, Frank W H; Tryggvason, Karl; Dijkman, Henri; Assmann, Karel J M; Veerkamp, Jacques H.; Monnens, Leo A H; Van Den Heuvel, Lambert P W J

    1997-01-01

    Heparan sulfate proteoglycans (HSPGs) are essential components of the glomerular basement membrane (GBM) carrying a strong anionic charge. A well- characterized extracellular HSPG is perlecan, ubiquitously expressed in basement membranes. A cDNA construct encoding domains I and II of human perlecan

  9. Matrimid-JUC-62 and Matrimid-PCN-250 mixed matrix membranes displaying light-responsive gas separation and beneficial ageing characteristics for CO2/N2 separation.

    Science.gov (United States)

    Prasetya, Nicholaus; Teck, Anastasia A; Ladewig, Bradley P

    2018-02-13

    The performance of two generation-3 light-responsive metal-organic framework (MOF), namely JUC-62 and PCN-250, was investigated in a mixed matrix membrane (MMM) form. Both of them were incorporated inside the matrimid as the polymer matrix. Using our custom-designed membrane testing cell, it was observed that the MMMs showed up to 9% difference in CO 2 permeability between its pristine and UV-irradiated condition. This shows that the light-responsive ability of the light-responsive MOFs could still be maintained. Thus, this finding is applicable in designing a smart material. Apart from that, the MMMs also has the potential to be applied for post-combustion carbon capture. At loadings up to 15 wt%, both CO 2 permeability and CO 2 /N 2 ideal selectivity could be significantly improved and surpassed the value exhibited by most of the MOF-matrimid MMM. Lastly the long term performance of the MMM was also evaluated and it was observed that both MMM could maintain their performance up to 1 month with only a slight decrease in CO 2 permeability observed for 10 wt% PCN-250-matrimid. This study then opens up the possibility to fabricate a novel anti-aging multifunctional membrane material that is applicable as a smart material and also in post combustion carbon capture applications.

  10. Mixed-matrix membranes with enhanced antifouling activity: probing the surface-tailoring potential of Tiron and chromotropic acid for nano-TiO2

    Science.gov (United States)

    Pal, Avishek; Dey, T. K.; Debnath, A. K.; Bhushan, Bharat; Sahu, A. K.; Bindal, R. C.; Kar, Soumitra

    2017-09-01

    Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO2 (nano-TiO2) by using two different organoligands, viz. Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, FT-nano-TiO2 and FC-nano-TiO2, respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for FT-nano-TiO2, whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for FC-nano-TiO2. The surface chemistry of the studied membranes, polysulfone (Psf): FT-nano-TiO2 UF and Psf: FC-nano-TiO2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites (-SO3 -H+ ), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz. 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

  11. Proteolytic processing of lysyl oxidase-like-2 in the extracellular matrix is required for crosslinking of basement membrane collagen IV.

    Science.gov (United States)

    López-Jiménez, Alberto J; Basak, Trayambak; Vanacore, Roberto M

    2017-10-13

    Lysyl oxidase-like-2 (LOXL2) is an enzyme secreted into the extracellular matrix that crosslinks collagens by mediating oxidative deamination of lysine residues. Our previous work demonstrated that this enzyme crosslinks the 7S domain, a structural domain that stabilizes collagen IV scaffolds in the basement membrane. Despite its relevant role in extracellular matrix biosynthesis, little is known about the structural requirements of LOXL2 that enable collagen IV crosslinking. In this study, we demonstrate that LOXL2 is processed extracellularly by serine proteases, generating a 65-kDa form lacking the first two scavenger receptor cysteine-rich domains. Site-specific mutagenesis to prevent proteolytic processing generated a full-length enzyme that is active in vitro toward a soluble substrate, but fails to crosslink insoluble collagen IV within the extracellular matrix. In contrast, the processed form of LOXL2 binds to collagen IV and crosslinks the 7S domain. Together, our data demonstrate that proteolytic processing is an important event that allows LOXL2-mediated crosslinking of basement membrane collagen IV. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Evaluating adhesion reduction efficacy of type I/III collagen membrane and collagen-GAG resorbable matrix in primary flexor tendon repair in a chicken model.

    Science.gov (United States)

    Turner, John B; Corazzini, Rubina L; Butler, Timothy J; Garlick, David S; Rinker, Brian D

    2015-09-01

    Reduction of peritendinous adhesions after injury and repair has been the subject of extensive prior investigation. The application of a circumferential barrier at the repair site may limit the quantity of peritendinous adhesions while preserving the tendon's innate ability to heal. The authors compare the effectiveness of a type I/III collagen membrane and a collagen-glycosaminoglycan (GAG) resorbable matrix in reducing tendon adhesions in an experimental chicken model of a "zone II" tendon laceration and repair. In Leghorn chickens, flexor tendons were sharply divided using a scalpel and underwent repair in a standard fashion (54 total repairs). The sites were treated with a type I/III collagen membrane, collagen-GAG resorbable matrix, or saline in a randomized fashion. After 3 weeks, qualitative and semiquantitative histological analysis was performed to evaluate the "extent of peritendinous adhesions" and "nature of tendon healing." The data was evaluated with chi-square analysis and unpaired Student's t test. For both collagen materials, there was a statistically significant improvement in the degree of both extent of peritendinous adhesions and nature of tendon healing relative to the control group. There was no significant difference seen between the two materials. There was one tendon rupture observed in each treatment group. Surgical handling characteristics were subjectively favored for type I/III collagen membrane over the collagen-GAG resorbable matrix. The ideal method of reducing clinically significant tendon adhesions after injury remains elusive. Both materials in this study demonstrate promise in reducing tendon adhesions after flexor tendon repair without impeding tendon healing in this model.

  13. Amino-Functionalized ZIF-7 Nanocrystals: Improved Intrinsic Separation Ability and Interfacial Compatibility in Mixed-Matrix Membranes for CO2 /CH4 Separation.

    Science.gov (United States)

    Xiang, Long; Sheng, Luqian; Wang, Chongqing; Zhang, Lixiong; Pan, Yichang; Li, Yanshuo

    2017-08-01

    Highly permeable and selective, as well as plasticization-resistant membranes are desired as promising alternatives for cost- and energy-effective CO 2 separation. Here, robust mixed-matrix membranes based on an amino-functionalized zeolitic imidazolate framework ZIF-7 (ZIF-7-NH 2 ) and crosslinked poly(ethylene oxide) rubbery polymer are successfully fabricated with filler loadings up to 36 wt%. The ZIF-7-NH 2 materials synthesized from in situ substitution of 2-aminobenzimidazole into the ZIF-7 structure exhibit enlarged aperture size compared with monoligand ZIF-7. The intrinsic separation ability for CO 2 /CH 4 on ZIF-7-NH 2 is remarkably enhanced as a result of improved CO 2 uptake capacity and diffusion selectivity. The incorporation of ZIF-7-NH 2 fillers simultaneously makes the neat polymer more permeable and more selective, surpassing the state-of-the-art 2008 Robeson upper bound. The chelating effect between metal (zinc) nodes of fillers and ester groups of a polymer provides good bonding, enhancing the mechanical strength and plasticization resistance of the neat polymer membrane. The developed novel ZIF-7 structure with amino-function and the resulting nanocomposite membranes are very attractive for applications like natural-gas sweetening or biogas purification. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)-Polysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS).

    Science.gov (United States)

    Jeazet, Harold B Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph

    2013-10-25

    Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model.

  15. Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)–Polysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS)

    Science.gov (United States)

    Jeazet, Harold B. Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph

    2013-01-01

    Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model. PMID:24957061

  16. Insulin requirements in type 1 diabetic pregnancy

    DEFF Research Database (Denmark)

    Callesen, Nicoline; Ringholm, Lene; Stage, Edna

    2012-01-01

    To evaluate the insulin requirements in women with type 1 diabetes during twin pregnancy compared with singleton pregnancy.......To evaluate the insulin requirements in women with type 1 diabetes during twin pregnancy compared with singleton pregnancy....

  17. Mixed-matrix membranes with enhanced antifouling activity: probing the surface-tailoring potential of Tiron and chromotropic acid for nano-TiO2.

    Science.gov (United States)

    Pal, Avishek; Dey, T K; Debnath, A K; Bhushan, Bharat; Sahu, A K; Bindal, R C; Kar, Soumitra

    2017-09-01

    Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO 2 (nano-TiO 2 ) by using two different organoligands, viz . Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, F T -nano-TiO 2 and F C -nano-TiO 2 , respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for F T -nano-TiO 2 , whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for F C -nano-TiO 2 . The surface chemistry of the studied membranes, polysulfone (Psf): F T -nano-TiO 2 UF and Psf: F C -nano-TiO 2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites ([Formula: see text]), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz . 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

  18. Three-Dimensional Graphene Matrix-Supported and Thylakoid Membrane-Based High-Performance Bioelectrochemical Solar Cell

    DEFF Research Database (Denmark)

    Pankratova, Galina; Pankratov, Dmitrii; Di Bari, Chiara

    2018-01-01

    A combination of thylakoid membranes (TMs) as photobiocatalysts with high-surface-area electroactive materials could hold great potential for sustainable “green” solar energy conversion. We have studied the orientated immobilization of TMs on high-surface-area graphene electrodes, which were...

  19. Molecular aspects of the interaction between MasonPfizer monkey virus matrix protein and artificial phospholipid membrane

    Czech Academy of Sciences Publication Activity Database

    Junková, P.; Prchal, J.; Spiwok, V.; Pleskot, Roman; Kadlec, J.; Krásný, Libor; Hynek, R.; Hrabal, R.; Ruml, T.

    2016-01-01

    Roč. 84, č. 11 (2016), s. 1717-1727 ISSN 0887-3585 Institutional support: RVO:61389030 ; RVO:61388971 Keywords : d-type retrovirus * force-field * nucleotide-sequence * myristate exposure * plasma-membrane * rhesus monkey Subject RIV: EB - Genetics ; Molecular Biology; EE - Microbiology, Virology (MBU-M) Impact factor: 2.289, year: 2016

  20. Molecular aspects of the interaction between Mason-Pfizer monkey virus matrix protein and artificial phospholipid membrane

    Czech Academy of Sciences Publication Activity Database

    Junková, P.; Prchal, J.; Spiwok, V.; Pleskot, Roman; Kadlec, Jan; Krásný, L.; Hynek, R.; Hrabal, R.; Ruml, T.

    2016-01-01

    Roč. 84, č. 11 (2016), s. 1717-1727 ISSN 0887-3585 Institutional support: RVO:61388963 Keywords : covalent labelling * mass spectrometry * multiscale molecular dynamics * protein-membrane interaction * phosphatidylinositol-(4,5)-bisphosphate * liposomes Subject RIV: CE - Biochemistry Impact factor: 2.289, year: 2016

  1. Autoimmune Hypoglycemia in Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Ambigapathy, Jayakumar; Sahoo, Jayaprakash; Kamalanathan, Sadishkumar

    2017-07-15

    Antibodies against exogenous insulin are common in type 1 diabetes mellitus patients. They can cause hypoglycemia, albeit uncommonly. A 14-year-old girl with type 1 diabetes mellitus presented with recurrent hypoglycemia. High insulin, low C-peptide and raised insulin antibody levels documented during hypoglycemia. Plasmapheresis led to remission of hypoglycemia. Antibodies to exogenous insulin should be considered as a cause of recurrent refractory hypoglycemia in type 1 diabetes mellitus patients.

  2. Type 1 Diabetes and Interferon Therapy

    OpenAIRE

    Nakamura, Kan; Kawasaki, Eiji; Imagawa, Akihisa; Awata, Takuya; Ikegami, Hiroshi; Uchigata, Yasuko; Kobayashi, Tetsuro; Shimada, Akira; Nakanishi, Koji; Makino, Hideichi; Maruyama, Taro; Hanafusa, Toshiaki

    2011-01-01

    OBJECTIVE Interferon therapy can trigger induction of several autoimmune diseases, including type 1 diabetes. To assess the clinical, immunologic, and genetic characteristics of type 1 diabetes induced by interferon therapy, we conducted a nationwide cross-sectional survey. RESEARCH DESIGN AND METHODS Clinical characteristics, anti-islet autoantibodies, and HLA-DR typing were examined in 91 patients for whom type 1 diabetes developed during or shortly after interferon therapy. RESULTS Median ...

  3. Eating disorders in type 1 diabetes

    DEFF Research Database (Denmark)

    Nash, J.; Skinner, T. C.

    2005-01-01

    There is some debate in the literature as to whether there is an increased risk of developing eating disorders in individuals with type 1 diabetes. This review located 12 empirical studies of eating pathology in females with type 1 diabetes. Review of these papers indicates...... that there is no evidence for an increase in the rates of anorexia or bulimia, in females with type 1 diabetes. However, the data do suggest that eating disorders not otherwise specified (EDNOS) are more prevalent in individuals with type 1 diabetes. Key features of these articles are reviewed and discussed....

  4. Effective enhancement of gas separation performance in mixed matrix membranes using core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons

    Science.gov (United States)

    Xue, Qingzhong; Pan, Xinglong; Li, Xiaofang; Zhang, Jianqiang; Guo, Qikai

    2017-02-01

    Novel core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons (MWCNT@GONRs) nanohybrids were successfully prepared using a modified chemical longitudinal unzipping method. Subsequently, the MWCNT@GONRs nanohybrids were used as fillers to enhance the gas separation performance of polyimide based mixed matrix membranes (MMMs). It is found that MMMs concurrently exhibited higher gas selectivity and higher gas permeability compared to pristine polyimide. The high gas selectivity could be attributed to the GONRs shell, which provided a selective barrier and large gas adsorbed area, while the high gas permeability resulted from the hollow structured MWCNTs core with smooth internal surface, which acted as a rapid transport channel. MWCNT@GONRs could be promising candidates to improve gas separation performance of MMMs due to the unique microstructures, ease of synthesis and low filling loading.

  5. Relapsing/remitting type 1 diabetes

    NARCIS (Netherlands)

    van Megen, Kayleigh M.; Spindler, Matthew P.; Keij, Fleur M.; Bosch, Ineke; Sprangers, Fleur; van Royen-Kerkhof, Annet; Nikolic, Tatjana; Roep, Bart O.

    2017-01-01

    Aims/hypothesis: Type 1 diabetes is believed to be an autoimmune disease associated with irreversible loss of insulin secretory function that follows a chronic progressive course. However, it has been speculated that relapsing/remitting disease progression may occur in type 1 diabetes. Methods: We

  6. Type 1 Diabetes: What Is It?

    Science.gov (United States)

    ... Videos for Educators Search English Español Type 1 Diabetes: What Is It? KidsHealth / For Parents / Type 1 ... español Diabetes tipo 1: ¿Qué es? What Is Diabetes? Diabetes is a disease that affects how the ...

  7. Overexpression of membrane sialic acid-specific sialidase Neu3 inhibits matrix metalloproteinase-9 expression in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Moon, Sung-Kwon; Cho, Seung-Hak; Kim, Kyung-Woon; Jeon, Jae Heung; Ko, Jeong-Heon; Kim, Bo Yeon; Kim, Cheorl-Ho

    2007-01-01

    The ganglioside-specific sialidase Neu3 has been suggested to participate in cell growth, migration, and differentiation. Recent reports suggest that sialidase may be involved in intimal thickening, an early stage in the development of atherosclerosis. However, the role of the Neu3 gene in vascular smooth muscle cells (VSMC) responses has not yet been elucidated. To determine whether a Neu3 is able to modulate VSMC growth, the effect of overexpression of the Neu3 gene on cell proliferation was examined. However, the results show that the overexpression of this gene has no effect on DNA synthesis and ERK phosphorylation in cultured VSMC in the presence of TNF-α. Because atherogenic effects need not be limited to proliferation, we decided to examine whether Neu3 exerted inhibitory effects on matrix metalloproteinase-9 (MMP-9) activity in TNF-α-induced VSMC. The expression of the Neu3 gene led to the inhibition of TNF-α-induced matrix metalloproteinase-9 (MMP-9) expression in VSMC as determined by zymography and immunoblot. Furthermore, Neu3 gene expression strongly decreased MMP-9 promoter activity in response to TNF-α. This inhibition was characterized by the down-regulation of MMP-9, which was transcriptionally regulated at NF-κB and activation protein-1 (AP-1) sites in the MMP-9 promoter. These findings suggest that the Neu3 gene represents a physiological modulator of VSMC responses that may contribute to plaque instability in atherosclerosis

  8. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin; S. Pillai, Renjith; Sabetghadam, Anahid; Benoit, Virginie; Normand, Pé rine; Marrot, Jerome; Menguy, Nicolas; Montero, David; Shepard, William; Tissot, Antoine; Martineau-Corcos, Charlotte; Sicard, Clé mence; Mihaylov, Mihail; Carn, Florent; Beurroeis, Isabelle; Llewellyn, Philip L.; De Weireld, Guy; Hadjiivanov, Konstantin; Gascon, Jorge; Kapteijn, Freek; Maurin, Guillaume; Steunou, Nathalie; Serre, Christian

    2017-01-01

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  9. The role of tetragonal-metal-organic framework-5 loadings with extra ZnO molecule on the gas separation performance of mixed matrix membrane

    International Nuclear Information System (INIS)

    Arjmandi, Mehrzad; Pakizeh, Majid; Pirouzram, Omid

    2015-01-01

    The effect of more ZnO molecule in tetragonal structure of MOF-5 than cubic structure on the gas permeation properties of T-MOF-5/polyetherimide mixed matrix membranes was investigated. T-MOF-5 was first successfully synthesized and carefully characterized by XRD, FTIR, SEM and N 2 adsorption technique at 77 K. Novel T-MOF-5/PEI MMMs were prepared using solution casting method and characterized by FTIR and SEM. The SEM pictures of the MMMs showed that T-MOF-5 nanocrystals changed the morphology of PEI and exhibited acceptable contacts between the filler particles and the polymer chains. Gas permeation properties of these membranes with different T-MOF-5 contents were studied for pure H 2 , CO 2 , CH 4 and N 2 gases. Permeation measurement showed that the all gases' permeability, diffusivity and solubility were increased with T-MOF-5 loading. H 2 permeability and the ideal selectivity of H 2 /CO 2 and H 2 /CH 4 in MMM with 25 wt% loading of T-MOF-5 nanocrystals were increased. This behavior was attributed to more ZnO molecule in T-MOF-5 structure. The experimental gas permeations through T-MOF-5/PEI nanocomposite with different filler loadings were fitted on Higuchi model. Good agreement between the experimental data and the predicted gas permeability was obtained

  10. The role of tetragonal-metal-organic framework-5 loadings with extra ZnO molecule on the gas separation performance of mixed matrix membrane

    Energy Technology Data Exchange (ETDEWEB)

    Arjmandi, Mehrzad; Pakizeh, Majid [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Pirouzram, Omid [Kurdistan University, Kurdistan (Iran, Islamic Republic of)

    2015-06-15

    The effect of more ZnO molecule in tetragonal structure of MOF-5 than cubic structure on the gas permeation properties of T-MOF-5/polyetherimide mixed matrix membranes was investigated. T-MOF-5 was first successfully synthesized and carefully characterized by XRD, FTIR, SEM and N{sub 2} adsorption technique at 77 K. Novel T-MOF-5/PEI MMMs were prepared using solution casting method and characterized by FTIR and SEM. The SEM pictures of the MMMs showed that T-MOF-5 nanocrystals changed the morphology of PEI and exhibited acceptable contacts between the filler particles and the polymer chains. Gas permeation properties of these membranes with different T-MOF-5 contents were studied for pure H{sub 2}, CO{sub 2}, CH{sub 4} and N{sub 2} gases. Permeation measurement showed that the all gases' permeability, diffusivity and solubility were increased with T-MOF-5 loading. H{sub 2} permeability and the ideal selectivity of H{sub 2}/CO{sub 2} and H{sub 2}/CH{sub 4} in MMM with 25 wt% loading of T-MOF-5 nanocrystals were increased. This behavior was attributed to more ZnO molecule in T-MOF-5 structure. The experimental gas permeations through T-MOF-5/PEI nanocomposite with different filler loadings were fitted on Higuchi model. Good agreement between the experimental data and the predicted gas permeability was obtained.

  11. Progesterone receptor membrane component 1 as the mediator of the inhibitory effect of progestins on cytokine-induced matrix metalloproteinase 9 activity in vitro.

    Science.gov (United States)

    Allen, Terrence K; Feng, Liping; Grotegut, Chad A; Murtha, Amy P

    2014-02-01

    Progesterone (P4) and the progestin, 17α-hydroxyprogesterone caproate, are clinically used to prevent preterm births (PTBs); however, their mechanism of action remains unclear. Cytokine-induced matrix metalloproteinase 9 (MMP-9) activity plays a key role in preterm premature rupture of the membranes and PTB. We demonstrated that the primary chorion cells and the HTR8/SVneo cells (cytotrophoblast cell line) do not express the classical progesterone receptor (PGR) but instead a novel progesterone receptor, progesterone receptor membrane component 1 (PGRMC1), whose role remains unclear. Using HTR8/SVneo cells in culture, we further demonstrated that 6 hours pretreatment with medroxyprogesterone acetate (MPA) and dexamethasone (Dex) but not P4 or 17α-hydroxyprogesterone hexanoate significantly attenuated tumor necrosis factor α-induced MMP-9 activity after a 24-hour incubation period. The inhibitory effect of MPA, but not Dex, was attenuated when PGRMC1 expression was successfully reduced by PGRMC1 small interfering RNA. Our findings highlight a possible novel role of PGRMC1 in mediating the effects of MPA and in modulating cytokine-induced MMP-9 activity in cytotrophoblast cells in vitro.

  12. Extracellular Matrix (ECM) Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair

    Science.gov (United States)

    Park, Sang-Hyug; Kim, Moon Suk; Kim, Young Jick; Choi, Byung Hyune; Lee, Chun Tek; Park, So Ra; Min, Byoung-Hyun

    2016-01-01

    Recombinant human transforming growth factor beta-3 (rhTGF-β3) is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM) membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS) are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs) using western blot and circular dichroism (CD) analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+) rhTGF-β3 EMLDS) in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair. PMID:27258120

  13. Extracellular Matrix (ECM Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair.

    Directory of Open Access Journals (Sweden)

    Soon Sim Yang

    Full Text Available Recombinant human transforming growth factor beta-3 (rhTGF-β3 is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs using western blot and circular dichroism (CD analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+ rhTGF-β3 EMLDS in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair.

  14. Revisiting the Aluminum Trimesate-based MOF (MIL-96): from Structure Determination to the Processing of Mixed Matrix Membranes for CO2 Capture.

    KAUST Repository

    Benzaqui, Marvin

    2017-11-08

    A microporous Al trimesate-based metal-organic framework (MOF), denoted MIL-96-(Al), was selected as a porous hybrid filler for the processing of mixed matrix membranes (MMMs) for CO2/N-2 postcombustion separation. First, the structural model of MIL-96-(Al) initially reported was revisited using a combination of synchrotron-based single-crystal X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory (DFT) calculations. In a second step, pure MIL-96-(Al) crystals differing by their size and aspect ratio, including anisotropic hexagonal platelets and nanoparticles of about 70 nm in diameter, were prepared. Then, a combination of in situ IR spectroscopy, single-gas, and CO2/N-2 coadsorption experiments, calorimetry, and molecular simulations revealed that MIL-96-(Al) nanoparticles show a relatively high CO2 affinity over N-2 owing to strong interactions between CO2 molecules and several adsorption sites such as Al3+ Lewis centers, coordinated water, and hydroxyl groups. Finally, the high compatibility between MIL-96-(Al) nanoparticles and the 6FDA-DAM polymer allowed the processing of homogeneous and defect-free MMMs with a high MOF loading (up to 25 wt %) that outperform pure polymer membranes for CO2/N-2 separation.

  15. Gas transport behavior of mixed-matrix membranes composed of silica nanoparticles in a polymer of intrinsic microporosity (PIM-1)

    KAUST Repository

    Ahn, Juhyeon; Chung, Wookjin; Pinnau, Ingo; Song, Jingshe; Du, Naiying; Robertson, Gilles P.; Guiver, Michael D.

    2010-01-01

    Recently, high-free volume, glassy ladder-type polymers, referred to as polymers of intrinsic microporosity (PIM), have been developed and their reported gas transport performance exceeded the Robeson upper bound trade-off for O2/N2 and CO2/CH4. The present work reports the gas transport behavior of PIM-1/silica nanocomposite membranes. The changes in free volume, as well as the presence and volume of the void cavities, were investigated by analyzing the density, thermal stability, and nano-structural morphology. The enhancement in gas permeability (e.g., He, H2, O2, N2, and CO2) with increasing filler content shows that the trend is related to the true silica volume and void volume fraction. Crown Copyright © 2009.

  16. Developmental expression of membrane type 4-matrix metalloproteinase (Mt4-mmp/Mmp17) in the mouse embryo

    Science.gov (United States)

    Clemente, Cristina; Montalvo, María Gregoria; Seiki, Motoharu; Arroyo, Alicia G.

    2017-01-01

    Matrix metalloproteinases (MMPs) constitute a large group of endoproteases that play important functions during embryonic development, tumor metastasis and angiogenesis by degrading components of the extracellular matrix. Within this family, we focused our study on Mt4-mmp (also called Mmp17) that belongs to a distinct subset that is anchored to the cell surface via a glycosylphosphatidylinositol (GPI) moiety and with the catalytic site exposed to the extracellular space. Information about its function and substrates is very limited to date, and little has been reported on its role in the developing embryo. Here, we report a detailed expression analysis of Mt4-mmp during mouse embryonic development by using a LacZ reporter transgenic mouse line. We showed that Mt4-mmp is detected from early stages of development to postnatal stages following a dynamic and restricted pattern of expression. Mt4-mmp was first detected at E8.5 limited to the intersomitic vascularization, the endocardial endothelium and the dorsal aorta. Mt4-mmpLacZ/+ cells were also observed in the neural crest cells, somites, floor plate and notochord at early stages. From E10.5, expression localized in the limb buds and persists during limb development. A strong expression in the brain begins at E12.5 and continues to postnatal stages. Specifically, staining was observed in the olfactory bulb, cerebral cortex, hippocampus, striatum, septum, dorsal thalamus and the spinal cord. In addition, LacZ-positive cells were also detected during eye development, initially at the hyaloid artery and later on located in the lens and the neural retina. Mt4-mmp expression was confirmed by quantitative RT-PCR and western blot analysis in some embryonic tissues. Our data point to distinct functions for this metalloproteinase during embryonic development, particularly during brain formation, angiogenesis and limb development. PMID:28926609

  17. Maculopathy and spinocerebellar ataxia type 1

    DEFF Research Database (Denmark)

    Lebranchu, Pierre; Le Meur, Guylène; Magot, Armelle

    2013-01-01

    Autosomal dominant cerebellar ataxia is a rare heterogeneous group of diseases characterized by cerebellar symptoms, often associated with other multisystemic signs. Mild optic neuropathy has been associated with spinocerebellar ataxia type 1 (SCA1), but macular dysfunction has been reported...

  18. Genetics Home Reference: type 1 diabetes

    Science.gov (United States)

    ... Jan 4. Review. Citation on PubMed or Free article on PubMed Central van Belle TL, Coppieters KT, von Herrath MG. Type 1 diabetes: etiology, immunology, and therapeutic strategies. Physiol Rev. 2011 Jan;91( ...

  19. Genetics Home Reference: distal arthrogryposis type 1

    Science.gov (United States)

    ... 1 is a disorder characterized by joint deformities (contractures) that restrict movement in the hands and feet. ... distal arthrogryposis type 1 . However, researchers speculate that contractures may be related to problems with muscle contraction ...

  20. Methylenetetrahydrofolate reductase gene polymorphism in type 1 ...

    African Journals Online (AJOL)

    Mohammed A AboElAsrar

    2012-05-05

    May 5, 2012 ... in type 1 diabetes mellitus: Relationship to microvascular complications ... b Pediatric Molecular Genetics Department, Ankara University, Turkey. Received 15 .... Patients with diabetic nephropathy were classified into two.

  1. Liraglutide for treating type 1 diabetes

    DEFF Research Database (Denmark)

    Dejgaard, Thomas Fremming; Frandsen, Christian Seerup; Holst, Jens Juul

    2016-01-01

    INTRODUCTION: Many persons with type 1 diabetes do not achieve glycemic targets, why new treatments, complementary to insulin, are of interest. Liraglutide, a long-acting glucagon-like peptide-1 receptor agonist could be a potential pharmacological supplement to insulin. This review discusses...... the mechanism of actions, efficacy and safety of liraglutide as add-on to insulin in persons with type 1 diabetes. AREAS COVERED: Physiological and clinical data on liraglutide in type 1 diabetes were reviewed. We searched the Cochrane library, MEDLINE and EMBASE, with the final search performed February 16...... there was no clinically relevant effect on HbA1c. Adverse events were mostly transient gastrointestinal side effects, primarily nausea. Based on the available data, liraglutide cannot be recommended as add-on therapy to insulin in persons with type 1 diabetes with the aim to improve glycemic control. Ongoing trials...

  2. Immunogenetics of type 1 diabetes mellitus

    African Journals Online (AJOL)

    EL-HAKIM

    to other autoimmune diseases, the etiology of T1D remains obscure but ..... T1D, type 1 diabetes; AIT, autoimmune thyroiditis; CD, celiac disease; AD, Addison's disease. Table 5. .... (GAD65Ab) in prediabetic adults developing diabetes.

  3. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  4. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  5. Type 1 Does The Two-Step: Type 1 Secretion Substrates With A Functional Periplasmic Intermediate.

    Science.gov (United States)

    Smith, Timothy J; Sondermann, Holger; O'Toole, George A

    2018-06-04

    Bacteria have evolved several secretion strategies for polling and responding to environmental flux and insult. Of these, the type 1 secretion system (T1SS) is known to secrete an array of biologically diverse proteins - from small < 10 kDa bacteriocins to gigantic adhesins with a mass over 1 MDa. For the last several decades T1SS have been characterized as a one-step translocation strategy whereby the secreted substrate is transported directly into the extracellular environment from the cytoplasm with no periplasmic intermediate. Recent phylogenetic, biochemical, and genetic evidence point to a distinct sub-group of T1SS machinery linked with a bacterial transglutaminase-like cysteine proteinase (BTLCP), which uses a two-step secretion mechanism. BTLCP-linked T1SS transport a class of repeats-in-toxin (RTX) adhesins that are critical for biofilm formation. The prototype of this RTX adhesin group, LapA of Pseudomonas fluorescens Pf0-1, uses a novel N-terminal retention module to anchor the adhesin at the cell surface as a secretion intermediate threaded through the outer membrane-localized, TolC-like protein LapE. This secretion intermediate is post-translationally cleaved by the BTLCP family LapG protein to release LapA from its cognate T1SS pore. Thus, secretion of LapA and related RTX adhesins into the extracellular environment appears to be a T1SS-mediated, two-step process that involves a periplasmic intermediate. In this review, we contrast the T1SS machinery and substrates of the BLTCP-linked two-step secretion process with those of the classical one-step T1SS to better understand the newly recognized and expanded role of this secretion machinery. Copyright © 2018 American Society for Microbiology.

  6. Should Type 1 diabetics fast in Ramadan.

    Science.gov (United States)

    Mohsin, Fauzia; Azad, Kishwar; Zabeen, Bedowra; Tayyeb, Samin; Baki, Abdul; Nahar, Nazmun

    2015-05-01

    Fasting during the holy month of Ramadan is obligatory for all healthy adult and adolescent Muslims from the age of 12 years. This involves abstaining from eating or drinking from early dawn (Suhur/Sehri) till sunset (Iftar).Fasting is not meant to create excessive hardships or impart any adverse effect to the Muslim individual. As such, Islam has exempted certain categories of people from fasting including young children, travelers, the sick, the elderly,and pregnant and lactating women. According to expert opinion, people with type 1 diabetes who fast during Ramadan are at very high risk of metabolic deterioration. However, some recent studies have demonstrated that individuals with type 1 diabetes who are otherwise healthy and stable, can fast during Ramadan provided they comply with the Ramadan focused management plan and are under close professional supervision. This article discusses how to assess, counsel, monitor and manage people with type 1 diabetes who wish to fast during Ramadan.

  7. Distal technologies and type 1 diabetes management.

    Science.gov (United States)

    Duke, Danny C; Barry, Samantha; Wagner, David V; Speight, Jane; Choudhary, Pratik; Harris, Michael A

    2018-02-01

    Type 1 diabetes requires intensive self-management to avoid acute and long-term health complications. In the past two decades, substantial advances in technology have enabled more effective and convenient self-management of type 1 diabetes. Although proximal technologies (eg, insulin pumps, continuous glucose monitors, closed-loop and artificial pancreas systems) have been the subject of frequent systematic and narrative reviews, distal technologies have received scant attention. Distal technologies refer to electronic systems designed to provide a service remotely and include heterogeneous systems such as telehealth, mobile health applications, game-based support, social platforms, and patient portals. In this Review, we summarise the empirical literature to provide current information about the effectiveness of available distal technologies to improve type 1 diabetes management. We also discuss privacy, ethics, and regulatory considerations, issues of global adoption, knowledge gaps in distal technology, and recommendations for future directions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Neurofibromatosis type 1: clinical and radiological aspects

    International Nuclear Information System (INIS)

    Muniz, Marcos Pontes; Souza, Antonio Soares; Bertelli, Erika Cristina Pavarino; Bertollo, Eny Maria Goloni

    2006-01-01

    Neurofibromatosis type 1 is a genetic disease with an incidence of approximately 1 in 3,000 people, characterized mainly by systemic and progressive involvement, manifesting by physical deformity and compromising of neurological functions. The diagnosis of the neurofibromatosis type 1 must be performed the earliest possible through clinical exams and familiar history. The use of imaging diagnosis as radiography, computed tomography, and magnetic resonance imaging is valuable for diagnosis, treatment, follow-up of patients and control of lesions, preventing complications. In this study we describe the clinical and radiological aspects of the neurofibromatosis type 1, considering clinical features, genetics, bone alterations in chest, vertebral column, upper and lower limbs, and craniofacial abnormalities. (author)

  9. Development and Characterization of Defect-Free Matrimid® Mixed-Matrix Membranes Containing Activated Carbon Particles for Gas Separation

    Directory of Open Access Journals (Sweden)

    Fynn Weigelt

    2018-01-01

    Full Text Available In this work, mixed-matrix membranes (MMMs for gas separation in the form of thick films were prepared via the combination of the polymer Matrimid® 5218 and activated carbons (AC. The AC particles had a mean particle size of 1.5 μm and a mean pore diameter of 1.9 nm. The films were prepared by slow solvent evaporation from casting solutions in chloroform, which had a varying polymer–AC ratio. It was possible to produce stable films with up to a content of 50 vol % of AC. Thorough characterization experiments were accomplished via differential scanning calorimetry and thermogravimetric analysis, while the morphology of the MMMs was also investigated via scanning electron microscopy. The gas transport properties were revealed by employing time-lag measurements for different pure gases as well as sorption balance experiments for the filler particles. It was found that defect free Matrimid® MMMs with AC were prepared and the increase of the filler content led to a higher effective permeability for different gases. The single gas selectivity αij of different gas pairs maintained stable values with the increase of AC content, regardless of the steep increase in the effective permeability of the pure gases. Estimation of the solubilities and the diffusivities of the Matrimid®, AC, and MMMs allowed for the explanation of the increasing permeabilities of the MMMs, with the increase of AC content by modelling.

  10. Learning Disabilities in Neurofibromatosis Type 1

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-12-01

    Full Text Available The frequency of specific leaning disabilities (SLD in neurofibromatosis type 1 (NF1 was determined in a cohort of 81 patients (43 males, 38 females; mean age 11 years 6 months; age range 8-16 followed at Children's Hospital, Westmead, NSW, Australia.

  11. Outcomes in type 1 diabetic pregnancies

    DEFF Research Database (Denmark)

    Jensen, Dorte Møller; Damm, Peter; Moelsted-Pedersen, Lars

    2004-01-01

    OBJECTIVE: The aim of this study was to compare pregnancy outcomes in type 1 diabetic pregnancies with the background population. RESEARCH DESIGN AND METHODS: This nationwide prospective multicenter study took place in eight Danish centers treating pregnant women with type 1 diabetes during 1993...... mortality rate was 3.1% in type 1 diabetic pregnancies compared with 0.75% in the background population (RR 4.1 [95% CI 2.9-5.6]), and the stillbirth rate was 2.1% compared with 0.45 (4.7 [3.2-7.0]). The congenital malformation rate was 5.0% in the study population and 2.8% (1.7 [1.3-2.2]) in the background......, daily self-monitoring was associated with a reduction in serious adverse outcomes. The caesarean section rate was 55.9 and 12.6%, respectively, and the risk of preterm delivery was 41.7 and 6.0%, respectively. CONCLUSIONS: Type 1 diabetic pregnancies are still complicated by considerably higher rates...

  12. Mouse adenovirus type 1 infection of macrophages

    NARCIS (Netherlands)

    Ashley, S.L.; Welton, A.R.; Harwood, K.M.; Rooijen, van N.; Spindler, K.R.

    2009-01-01

    Mouse adenovirus type 1 (MAV-1) causes acute and persistent infections in mice, with high levels of virus found in the brain, spinal cord and spleen in acute infections. MAV-1 infects endothelial cells throughout the mouse, and monocytes/macrophages have also been implicated as targets of the virus.

  13. Tumor cell invasion of collagen matrices requires coordinate lipid agonist-induced G-protein and membrane-type matrix metalloproteinase-1-dependent signaling

    Directory of Open Access Journals (Sweden)

    Anthis Nicholas J

    2006-12-01

    Full Text Available Abstract Background Lysophosphatidic acid (LPA and sphingosine 1-phosphate (S1P are bioactive lipid signaling molecules implicated in tumor dissemination. Membrane-type matrix metalloproteinase 1 (MT1-MMP is a membrane-tethered collagenase thought to be involved in tumor invasion via extracellular matrix degradation. In this study, we investigated the molecular requirements for LPA- and S1P-regulated tumor cell migration in two dimensions (2D and invasion of three-dimensional (3D collagen matrices and, in particular, evaluated the role of MT1-MMP in this process. Results LPA stimulated while S1P inhibited migration of most tumor lines in Boyden chamber assays. Conversely, HT1080 fibrosarcoma cells migrated in response to both lipids. HT1080 cells also markedly invaded 3D collagen matrices (~700 μm over 48 hours in response to either lipid. siRNA targeting of LPA1 and Rac1, or S1P1, Rac1, and Cdc42 specifically inhibited LPA- or S1P-induced HT1080 invasion, respectively. Analysis of LPA-induced HT1080 motility on 2D substrates vs. 3D matrices revealed that synthetic MMP inhibitors markedly reduced the distance (~125 μm vs. ~45 μm and velocity of invasion (~0.09 μm/min vs. ~0.03 μm/min only when cells navigated 3D matrices signifying a role for MMPs exclusively in invasion. Additionally, tissue inhibitors of metalloproteinases (TIMPs-2, -3, and -4, but not TIMP-1, blocked lipid agonist-induced invasion indicating a role for membrane-type (MT-MMPs. Furthermore, MT1-MMP expression in several tumor lines directly correlated with LPA-induced invasion. HEK293s, which neither express MT1-MMP nor invade in the presence of LPA, were transfected with MT1-MMP cDNA, and subsequently invaded in response to LPA. When HT1080 cells were seeded on top of or within collagen matrices, siRNA targeting of MT1-MMP, but not other MMPs, inhibited lipid agonist-induced invasion establishing a requisite role for MT1-MMP in this process. Conclusion LPA is a

  14. Premarriage counseling in Type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Gagan Priya

    2018-01-01

    Full Text Available Type 1 diabetes is a challenging illness and needs lifelong diabetes self-care. At the same time, there is a significant stigma associated with it, especially with relation to marriage. There are concerns related to premarriage disclosure, marital relationship, ability to procreate, risk during pregnancy in women, and the risk of disease in children. In this document, we discuss the issue of disease-related stigma which may become a significant challenge for a prospective spouse and the impact of type 1 diabetes on marital relationships and procreation. We also highlight the need for premarriage counseling to ensure long-term success in achieving both individual and interpersonal well-being.

  15. Reporting Severe Hypoglycemia in Type 1 Diabetes

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2017-01-01

    PURPOSE OF REVIEW: To describe potential factors influencing reporting of severe hypoglycemia in adult patients with type 1 diabetes and to analyze their effect on reported rates of severe hypoglycemia. RECENT FINDINGS: Reported rates of severe hypoglycemia defined as need for third party...... by partners report higher rates of severe hypoglycemia. There is a large variation between studies reporting incidence and prevalence of severe hypoglycemia in patients with type 1 diabetes, mainly explained by definition of severity, methods of reporting, and patient selection. These findings call...... hypoglycemia are 0.02-0.5 events per patient-year and 1-29%, respectively. When subjects with recurrent severe hypoglycemia in the past or suffering from impaired hypoglycemia awareness are excluded from participation in studies, lower rates are reported. Studies applying anonymous reporting or reporting...

  16. Genetic risk factors for type 1 diabetes

    DEFF Research Database (Denmark)

    Pociot, Flemming; Lernmark, Åke

    2016-01-01

    Type 1 diabetes is diagnosed at the end of a prodrome of β-cell autoimmunity. The disease is most likely triggered at an early age by autoantibodies primarily directed against insulin or glutamic acid decarboxylase, or both, but rarely against islet antigen-2. After the initial appearance of one...... is generally needed. The pathogenesis can be divided into three stages: 1, appearance of β-cell autoimmunity, normoglycaemia, and no symptoms; 2, β-cell autoimmunity, dysglycaemia, and no symptoms; and 3, β-cell autoimmunity, dysglycaemia, and symptoms of diabetes. The genetic association with each one...... of the three stages can differ. Type 1 diabetes could serve as a disease model for organ-specific autoimmune disorders such as coeliac disease, thyroiditis, and Addison's disease, which show similar early markers of a prolonged disease process before clinical diagnosis....

  17. Metformin in adults with type 1 diabetes

    DEFF Research Database (Denmark)

    Petrie, John R; Chaturvedi, Nish; Ford, Ian

    2017-01-01

    AIMS: Cardiovascular (CV) disease is a major cause of reduced life expectancy in type 1 diabetes (T1D). Intensive insulin therapy prevents CV complications but is constrained by hypoglycaemia and weight gain. Adjunct metformin reduces insulin dose requirement and stabilizes weight...... but there are no data on its cardiovascular effects. We have therefore initiated an international double-blind, randomized, placebo-controlled trial (REMOVAL: REducing with MetfOrmin Vascular Adverse Lesions in type 1 diabetes) to examine whether metformin reduces progression of atherosclerosis in adults with T1D....... Individuals ≥40 years of age with T1D for ≥5 years are eligible if they have ≥3 of 10 specified CV risk factors. The enrolment target is 500 participants in 17 international centres. MATERIALS AND METHODS: After 12 weeks of single-blind placebo-controlled run-in, participants with ≥ 70% adherence...

  18. Diabetes in young: Beyond type 1

    Directory of Open Access Journals (Sweden)

    Anju Virmani

    2012-01-01

    Full Text Available Although majority of diabetes in children is type1 diabetes, childhood type2 diabetes prevalence is rapidly increasing due to changing lifestyle. Most patients can be definitely grouped into either of the two but some present diagnostic difficulty due to overlapping and non specific clinical features and laboratory findings. MODY and several other diseases affecting the pancreas also result in childhood diabetes. Treatment of diabetes in children presents unique challenges and primary prevention is of prime importance.

  19. Birth Weight in Type 1 Diabetic Pregnancy

    Directory of Open Access Journals (Sweden)

    Jacquemyn Yves

    2010-01-01

    Full Text Available Our aim was to investigate whether birth weight in mothers with diabetes mellitus type 1 is higher as compared to nondiabetic controls. Methods. A retrospective study was performed using an existing database covering the region of Flanders, Belgium. Data included the presence of diabetes type 1, hypertension, parity, maternal age, the use artificial reproductive technology, fetal- neonatal death, congenital anomalies, admission to a neonatal intensive care unit, and delivery by Caesarean section or vaginally. Results. In the period studied, 354 women with diabetes type 1 gave birth and were compared with 177.471 controls. Women with type 1 diabetes more often had a maternal age of over 35 years (16.7% versus 12.0%, P=.008, OR 1.46; 95% CI 1.09–1.95. They more frequently suffered hypertension in pregnancy (19.5% versus 4.7%, P<.0001, OR 4.91; 95% CI 3.73–6.44. Perinatal death was significantly higher in the diabetes mellitus group (3.05% versus 0.73%, P<.0001, OR 4.28; 95% CI 2.22–8.01. Caesarean section was performed almost 5 times as frequently in the diabetes versus the control group (OR 4.57; 95% CI 3.70–5.65. Birth weight was significantly higher in diabetic pregnant women from 33 until 38 weeks included, but those reaching 39 weeks and later were not different with control groups. Conclusion. In Belgium, diabetic pregnancy still carries a high risk for fetal and maternal complications; in general birth weight is significantly higher but for those reaching term there is no significant difference in birth weight.

  20. Exploring diabetes type 1-related stigma.

    Science.gov (United States)

    Abdoli, Samereh; Abazari, Parvaneh; Mardanian, Leila

    2013-01-01

    Empowerment of people with diabetes means integrating diabetes with identity. However, others' stigmatization can influence it. Although diabetes is so prevalent among Iranians, there is little knowledge about diabetes-related stigma in Iran. The present study explored diabetes-related stigma in people living with type 1 diabetes in Isfahan. A conventional content analysis was used with in-depth interview with 26 people with and without diabetes from November 2011 to July 2012. A person with type 1 diabetes was stigmatized as a miserable human (always sick and unable, death reminder, and intolerable burden), rejected marriage candidate (busy spouse, high-risk pregnant), and deprived of a normal life [prisoner of (to must), deprived of pleasure]. Although, young adults with diabetes undergo all aspects of the social diabetes-related stigma; in their opinion they were just deprived of a normal life. It seems that in Isfahan, diabetes-related stigma is of great importance. In this way, conducting an appropriate intervention is necessary to improve the empowerment process in people with type 1 diabetes in order to reduce the stigma in the context.

  1. Matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in paediatric burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors.

    Science.gov (United States)

    Weremijewicz, Artur; Matuszczak, Ewa; Sankiewicz, Anna; Tylicka, Marzena; Komarowska, Marta; Tokarzewicz, Anna; Debek, Wojciech; Gorodkiewicz, Ewa; Hermanowicz, Adam

    2018-01-30

    The purpose of this study was the determination of matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in the blood plasma of burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors. 31 children scalded by hot water who were managed at the Department of Paediatric Surgery between 2014-2015, after primarily presenting with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2,5+1 years). There were 10 girls and 21 boys. Venous blood samples were drawn 2-6h, and 12-16h after the thermal injury, and on the subsequent days 3, 5 and 7. The matrix metalloproteinase-2, collagen type IV and laminin-5 concentrations were assessed using Surface Plasmon Resonance Imaging by the investigators blinded to the other data. The MMP-2, laminin-5 and collagen type IV concentrations in the blood plasma of patients with burns, were highest 12-16h after thermal injury, the difference was statistically significant. The MMP-2, laminin-5 and collagen type IV concentrations measured 3 days, 5 days and 7 days after the thermal injury, slowly decreased over time, and on the 7th day reached the normal range, when compared with the concentration measured in controls. Current work is the first follow-up study regarding MMP-2 in burns. MMP-2, laminin-5 and collagen type IV levels were elevated early after burn injury in the plasma of studied patients, and were highest 12-16h after the injury. MMP-2, laminin-5 and collagen type IV levels were not proportional to the severity of the burn. We believe in the possibility that the gradual decrease of MMP-2, collagen type IV and laminin-5 concentrations could be connected with the process of healing, but to prove it, more investigation is needed in this area. The SPR imaging biosensor is a good diagnostic tool for determination of MMP-2, laminin-5 and collagen type IV in blood plasma of patients with burns. Copyright © 2017 Elsevier Ltd

  2. Reduction of facial wrinkles by hydrolyzed water-soluble egg membrane associated with reduction of free radical stress and support of matrix production by dermal fibroblasts

    Directory of Open Access Journals (Sweden)

    Jensen GS

    2016-10-01

    Full Text Available Gitte S Jensen,1 Bijal Shah,2 Robert Holtz,3 Ashok Patel,4 Donald C Lo2 1NIS Labs, Klamath Falls, OR, 2Department of Neurobiology, Center for Drug Discovery, Duke University Medical Center, Durham, NC, 3BioInnovation Laboratories, Inc., Lakewood, CO, 4Centre Manufacturing LLC, Eden Prairie, MN, USA Objective: The aim of this study was to evaluate the effects of water-soluble egg membrane (WSEM on wrinkle reduction in a clinical pilot study and to elucidate specific mechanisms of action using primary human immune and dermal cell-based bioassays.Methods: To evaluate the effects of topical application of WSEM (8% on human skin, an open-label 8-week study was performed involving 20 healthy females between the age of 45 years and 65 years. High-resolution photography and digital analysis were used to evaluate the wrinkle depth in the facial skin areas beside the eye (crow’s feet. WSEM was tested for total antioxidant capacity and effects on the formation of reactive oxygen species by human polymorphonuclear cells. Human keratinocytes (HaCaT cells were used for quantitative polymerase chain reaction analysis of the antioxidant response element genes Nqo1, Gclm, Gclc, and Hmox1. Evaluation of effects on human primary dermal fibroblasts in vitro included cellular viability and production of the matrix components collagen and elastin.Results: Topical use of a WSEM-containing facial cream for 8 weeks resulted in a significant reduction of wrinkle depth (P<0.05. WSEM contained antioxidants and reduced the formation of reactive oxygen species by inflammatory cells in vitro. Despite lack of a quantifiable effect on Nrf2, WSEM induced the gene expression of downstream Nqo1, Gclm, Gclc, and Hmox1 in human keratinocytes. Human dermal fibroblasts treated with WSEM produced more collagen and elastin than untreated cells or cells treated with dbcAMP control. The increase in collagen production was statistically significant (P<0.05.Conclusion: The topical use

  3. Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

    Science.gov (United States)

    Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

    2011-10-01

    The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

  4. Congenital CMV with LAD type 1 and NK cell deficiency.

    Science.gov (United States)

    Rai, Narendra; Thakur, Neha

    2013-08-01

    We report a rare case of congenital cytomegalovirus (CMV) in a patient who was subsequently diagnosed as leukocyte adhesion defect type 1 with natural killer cell deficiency. The clinical course was complicated by severe CMV pneumonitis during the newborn period. Thereafter the infant suffered from recurrent skin infections without pus formation, otitis media, and bronchopneumonia since 3 months of age. The patient had congenital CMV infection as urine and blood plasma was positive for CMV from day 12 onward. Neutrophil chemotaxis studies showed a decrease in directed chemotaxis. Neutrophils were dyspoetic and nonfunctional lacking HLA DR, CD11c, and CD18. Lymphocytes were polyclonal but lacked CD56, CD16, and surface membrane immunoglobulin.

  5. Teleconsultation in type 1 diabetes mellitus (TELEDIABE).

    Science.gov (United States)

    Bertuzzi, Federico; Stefani, Ilario; Rivolta, Benedetta; Pintaudi, Basilio; Meneghini, Elena; Luzi, Livio; Mazzone, Antonino

    2018-02-01

    The growing incidence of diabetes and the need to contain healthcare costs empower the necessity to identify new models of care. Telemedicine offers an acknowledged instrument to provide clinical health care at a distance, increasing patient compliance and the achievement of therapeutical goals. The objective was to test the feasibility and the efficacy in the improvement of the glycemic control of the teleconsultation for patients with type 1 diabetes mellitus. A randomized open-label, parallel arms, controlled trial was conducted in two diabetes centers in Italy. Participants affected by type 1 diabetes mellitus have been randomly (1:1) assigned to receive their visits as standard or a web-based care. Patients in the teleconsultation group can arrange their appointments on a Web site and can also have access to web educational courses or to nutritional and psychological counseling. The primary outcome was the assessment of glycemic control by HbA1c measurement after a 12-month follow-up. Overall 74 participants were followed for 1 year. HbA1c changes were not statistically different within (p = 0.56 for standard care group; p = 0.45 for telemedicine group) and between (p = 0.60) groups when considering differences from baseline to the end of the study. Patients randomized to teleconsultation reported reduced severe hypoglycemic episodes (p = 0.03). In addition, they were largely satisfied with the activities, perceived a good improvement in the self-management of the diabetes, and reported to have a time saving and a cost reduction. In conclusion, TELEDIABE proposes a new system for the management of patients with type 1 diabetes mellitus.

  6. Setting research priorities for Type 1 diabetes.

    Science.gov (United States)

    Gadsby, R; Snow, R; Daly, A C; Crowe, S; Matyka, K; Hall, B; Petrie, J

    2012-10-01

    Research priorities are often set by academic researchers or the pharmaceutical industry. The interests of patients, carers and clinicians may therefore be overlooked and research questions that matter may be neglected. The aims of this study were to collect uncertainties about the treatment of Type 1 diabetes from patients, carers and health professionals, and to collate and prioritize these uncertainties to develop a top 10 list of research priorities, using a structured priority-setting partnership of patients, carers, health professionals and diabetes organizations, as described by the James Lind Alliance. A partnership of interested organizations was set up, and from this a steering committee of 10 individuals was formed. An online and paper survey was used to identify uncertainties. These were collated, and the steering group carried out an interim priority-setting exercise with partner organizations. This group of uncertainties was then voted on to give a smaller list that went forward to the final priority-setting workshop. At this meeting, a final list of the top 10 research priorities was agreed. An initial 1141 uncertainties were described. These were reduced to 88 indicative questions, 47 of which went out for voting. Twenty-four were then taken forward to a final priority-setting workshop. This workshop resulted in a list of top 10 research priorities in Type 1 diabetes. We have shown that it is possible using the James Lind Alliance process to develop an agreed top 10 list of research priorities for Type 1 diabetes from health professionals, patients and carers. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  7. Insulinbehandling af voksne med type 1-diabetes

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2015-01-01

    Whereas insulin treatment of type 1 diabetes formerly was limited by the availability of one or a few types of insulin with suboptimal pharmacokinetic properties, insulin analogues with more fitting physiological action profiles have now been developed and ultimately near-physiological insulin...... treatment can be delivered with insulin pumps. Adjustments of insulin dosing can be rationally based on dosing algorithms. This requires frequent glucose measurements and knowledge about dietary carbohydrate content. Today, the treatment and its complexity are individualized according to needs and wishes...

  8. Insulinbehandling af voksne med type 1-diabetes

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2015-01-01

    Whereas insulin treatment of type 1 diabetes formerly was limited by the availability of one or a few types of insulin with suboptimal pharmacokinetic properties, insulin analogues with more fitting physiological action profiles have now been developed and ultimately near-physiological insulin...... treatment can be delivered with insulin pumps. Adjustments of insulin dosing can be rationally based on dosing algorithms. This requires frequent glucose measurements and knowledge about dietary carbohydrate content. Today, the treatment and its complexity are individualized according to needs and wishes...... of the patient....

  9. Therapeutic perspectives in type-1 diabetes

    CERN Document Server

    SINGH, PRACHI; TUPALLY, KARNAKER R; PODDAR, KINGSHUK; Tan, Aaron; VENKATESAN, VENKY; PAREKH, HARENDRA S; PASTORIN, GIORGIA

    2016-01-01

    This book provides critical insights into and appraisals of recent breakthroughs in type 1 diabetes modulation, with a particular emphasis on the potential impact of current prevention and treatment strategies. It also discusses recent successes and failures in clinical trials. Presenting an comprehensive overview of the disease, it is especially useful for newcomers in the field. It also includes illustrations, which make it easy for the reader to grasp the basic concepts involved. Furthermore, the tables include concise and easy-to-understand information on current clinical trials.

  10. Teenage pregnancy in type 1 diabetes mellitus.

    Science.gov (United States)

    Carmody, David; Doyle, Aoife; Firth, Richard G R; Byrne, Maria M; Daly, Sean; Mc Auliffe, Fionnuala; Foley, Micheal; Coulter-Smith, Samuel; Kinsley, Brendan T

    2010-03-01

    Younger maternal age at delivery has been linked to adverse reproductive outcomes. Pregnancy complicated by type 1 diabetes mellitus (T1DM) is also associated with adverse pregnancy outcomes. Optimising diabetic glycaemic control prior to pregnancy is known to reduce the rate of congenital abnormalities and improve pregnancy outcomes. Teenage pregnancies are not usually planned and little data exist on teenage pregnancy complicated by T1DM. We sought to identify the glycemic control achieved in teenage pregnancy with T1DM and to clarify if there is an associated increase in adverse pregnancy outcomes compared to those seen in older women with T1DM. We compared outcomes in 18 teenagers (TG) with 582 older women with T1DM (CON) from 1995-2007. TG booked to the combined diabetes-obstetrical service at a median gestational age of 11 weeks (range 6-22) compared to 7 weeks in CON (range 4-40, p teenage women with T1DM book later to specialised care and have worse glycaemic control in pregnancy compared to older women with T1DM. This group also appear to be more insulin resistant than older women in early pregnancy. Our data would suggest that teenagers with type 1 diabetes mellitus may constitute a high-risk group for adverse pregnancy outcomes.

  11. Neurofibromatosis type 1: brain stem tumours

    International Nuclear Information System (INIS)

    Bilaniuk, L.T.; Molloy, P.T.; Zimmerman, R.A.; Phillips, P.C.; Vaughan, S.N.; Liu, G.T.; Sutton, L.N.; Needle, M.

    1997-01-01

    We describe the clinical and imaging findings of brain stem tumours in patients with neurofibromatosis type 1 (NF1). The NF1 patients imaged between January 1984 and January 1996 were reviewed and 25 patients were identified with a brain stem tumour. Clinical, radiographical and pathological results were obtained by review of records and images. Brain stem tumour identification occurred much later than the clinical diagnosis of NF1. Medullary enlargement was most frequent (68 %), followed by pontine (52 %) and midbrain enlargement (44 %). Patients were further subdivided into those with diffuse (12 patients) and those with focal (13 patients) tumours. Treatment for hydrocephalus was required in 67 % of the first group and only 15 % of the second group. Surgery was performed in four patients and revealed fibrillary astrocytomas, one of which progressed to an anaplastic astrocytoma. In 40 % of patients both brain stem and optic pathway tumours were present. The biological behaviour of brain stem tumours in NF1 is unknown. Diffuse tumours in the patients with NF1 appear to have a much more favourable prognosis than patients with similar tumours without neurofibromatosis type 1. (orig.). With 7 figs., 3 tabs

  12. Immune intervention in type 1 diabetes.

    Science.gov (United States)

    Michels, Aaron W; Eisenbarth, George S

    2011-06-01

    Type 1 diabetes (T1D) is a chronic autoimmune disease that results in the specific immune destruction of insulin producing beta cells. Currently there is no cure for T1D and treatment for the disease consists of lifelong administration of insulin. Immunotherapies aimed at preventing beta cell destruction in T1D patients with residual c-peptide or in individuals developing T1D are being evaluated. Networks of researchers such as TrialNet and the Immune Tolerance Network in the U.S. and similar networks in Europe have been established to evaluate such immunotherapies. This review focuses on immune intervention for the prevention and amelioration of human T1D with a focus on potential immune suppressive, antigen specific and environmental therapies. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Type 1 diabetes care updates: Tanzania

    Directory of Open Access Journals (Sweden)

    Kandi Catherine Muze

    2015-01-01

    Full Text Available Tanzania is located in east Africa with a population of 45 million. The country′s population is growing at 2.5% annually. The International Diabetes Federation Child Sponsorship Program was launched in Tanzania in 2005. The number of type 1 diabetes mellitus children enrolled in the changing diabetes in children program in Tanzania has augmented from almost below 50 in 2005 to over 1200 in 2014. The country had an overall trend of HbA1c value of 14% in 2005 while the same has reduced over the years to 10% in 2012-13. The program has been able to reduce the proportion of patients with HbA1c values of 11-14%; from 71.9% in 2008 to 49.8% in 2012-13. The challenges, which CDiC faces are misdiagnosis, low public awareness, and stigma especially in the reproductive age/adolescent groups.

  14. Microcephalic osteodysplastic primordial dwarfism type 1.

    Science.gov (United States)

    Ferrell, Steven; Johnson, Aaron; Pearson, Waylon

    2016-06-16

    Microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) is an uncommon cause of microcephaly and intrauterine growth retardation in a newborn. Early identifying features include but are not limited to sloping forehead, micrognathia, sparse hair, including of eyebrows and short limbs. Immediate radiological findings may include partial or complete agenesis of the corpus callosum, interhemispheric cyst and shallow acetabula leading to dislocation. Genetic testing displaying a mutation in RNU4ATAC gene is necessary for definitive diagnosis. Early identification is important as MOPD1 is an autosomal recessive condition and could present in subsequent pregnancies. The purpose of this case is to both identify and describe some common physical findings related to MOPD1. We present a case of MOPD1 in a girl born to non-consanguineous parents that was distinct for subglottic stenosis and laryngeal cleft. 2016 BMJ Publishing Group Ltd.

  15. Research progress of spinocerebellar ataxia type 1

    Directory of Open Access Journals (Sweden)

    Lin-wei ZHANG

    2014-05-01

    Full Text Available Spinocerebellar ataxia type 1 (SCA1 is a kind of autosomal dominant genetic neurodegenerative disorder. To date, the pathogenesis of SCA1 remains unclear. Studies in numerous SCA1 experimental models, including transgenic mice, transgenic drosophila and induced pluripotent stem cells, have shown that phosphorylation of S776 in mutant ataxin-1, molecular chaperones, ubiquitin-proteasome system and down-regulation of several components of RAS-MAPK-MSK1 pathway may involve in the pathogenesis of SCA1. In this review, the clinical and pathological features of SCA1, and the latest advances of pathogenesis, model systems and therapeutic exploration will be briefly summarized. doi: 10.3969/j.issn.1672-6731.2014.05.017

  16. Type 1 diabetes and multiple sclerosis

    DEFF Research Database (Denmark)

    Nielsen, N.M.; Westergaard, T.; Frisch, M.

    2006-01-01

    BACKGROUND: Type 1 diabetes mellitus (T1D) and multiple sclerosis (MS) contribute considerably to the burden of autoimmune diseases in young adults. Although HLA patterns of T1D and MS are considered mutually exclusive, individual and familial co-occurrence of the 2 diseases has been reported...... Multiple Sclerosis Register were used to identify patients with T1D, defined as patients in whom diabetes was diagnosed before age 20 years (N = 6078), and patients with MS (N = 11 862). First-degree relatives (N = 14,771) of patients with MS were identified from family information in the Danish Civil....... OBJECTIVE: To assess the co-occurrence of T1D and MS by estimating the risk for MS in patients with T1D and the risk for T1D in first-degree relatives of patients with MS. DESIGN, SETTING, AND PARTICIPANTS: Two population-based disease registers, the Danish Hospital Discharge Register and the Danish...

  17. Teenage pregnancy in type 1 diabetes mellitus.

    LENUS (Irish Health Repository)

    Carmody, David

    2010-03-01

    Younger maternal age at delivery has been linked to adverse reproductive outcomes. Pregnancy complicated by type 1 diabetes mellitus (T1DM) is also associated with adverse pregnancy outcomes. Optimising diabetic glycaemic control prior to pregnancy is known to reduce the rate of congenital abnormalities and improve pregnancy outcomes. Teenage pregnancies are not usually planned and little data exist on teenage pregnancy complicated by T1DM. We sought to identify the glycemic control achieved in teenage pregnancy with T1DM and to clarify if there is an associated increase in adverse pregnancy outcomes compared to those seen in older women with T1DM. We compared outcomes in 18 teenagers (TG) with 582 older women with T1DM (CON) from 1995-2007. TG booked to the combined diabetes-obstetrical service at a median gestational age of 11 weeks (range 6-22) compared to 7 weeks in CON (range 4-40, p < 0.02). Glycaemic was worse in TG compared to CON at 13, 26 and 35 weeks gestation, despite higher insulin doses. First trimester miscarriage rate did not differ between groups. Major congenital anomaly rate was 6.2% (1\\/16) compared to 3.2% in CON. This preliminary study has demonstrated that pregnant teenage women with T1DM book later to specialised care and have worse glycaemic control in pregnancy compared to older women with T1DM. This group also appear to be more insulin resistant than older women in early pregnancy. Our data would suggest that teenagers with type 1 diabetes mellitus may constitute a high-risk group for adverse pregnancy outcomes.

  18. Metamaterial membranes

    International Nuclear Information System (INIS)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2017-01-01

    We introduce a new class of metamaterial device to achieve separation of compounds by using coordinate transformations and metamaterial theory. By rationally designing the spatial anisotropy for mass diffusion, we simultaneously concentrate different compounds in different spatial locations, leading to separation of mixtures across a metamaterial membrane. The separation of mixtures into their constituent compounds is critically important in biophysics, biomedical, and chemical applications. We present a practical case where a mixture of oxygen and nitrogen diffusing through a polymeric planar matrix is separated. This work opens doors to new paradigms in membrane separations via coordinate transformations and metamaterials by introducing novel properties and unconventional mass diffusion phenomena. (paper)

  19. Type 1 diabetes: The Bangladesh perspective

    Directory of Open Access Journals (Sweden)

    Kishwar Azad

    2015-01-01

    Full Text Available Diabetes mellitus (DM is a common endocrine disorder among children and adolescents in Bangladesh. The latest International Diabetes Federation atlas estimated the incidence of type 1 DM (T1DM in Bangladesh as 4.2 new cases of T1DM/100,000 children (0-14 years/year, in 2013. Diabetes, being a lifelong disease, places a huge burden on the economy of the most densely populated, and resource-poor country of the world. The Diabetic Association of Bangladesh (BADAS, the largest of its kind in the world, provides comprehensive care to the biggest number of diabetics at any one centre and is engaged in advocacy. Although sounding grandiose, it′s aims that ′no diabetic shall die untreated, unfed or unemployed, even if poor′ is pursued with a passion. Recently BADAS has been supported in its endeavor for children and adolescents by two programmes; viz the Changing Diabetes in Children program (a joint initiative of BADAS, the World Diabetes Foundation and Novo Nordisk, and the Life for a Child Programme (LFAC supported by the IDF. Numerous studies from the prosperous countries have demonstrated the incidence of T1DM is increasing. Data from the CDiC clinic at BIRDEM shows a rising trend in patients presenting with classical T1DM. In addition, the pattern of DM is changing.

  20. Type 1 diabetes guidelines: Are they enough?

    Directory of Open Access Journals (Sweden)

    Abdul Abdul Zargar

    2015-01-01

    Full Text Available The discovery of insulin by Banting and Best in 1922 changed the landscape of type 1 diabetes mellitus (T1DM. Guidelines on T1DM should be evidence based and should emphasize comprehensive risk management. Guidelines would improve awareness amongst governments, state health care providers and the general public about the serious long-term implications of poorly managed diabetes and of the essential resources needed for optimal care. T1DM requires lifelong daily medication, regular control as well as access to facilities to manage acute and chronic complications. American Diabetes Association 2014 guidelines recommends annual nephropathy screening for albumin levels; random spot urine sample for albumin-to-creatinine ratio at start of puberty or age ≥10 years, whichever is earlier, once the child has had diabetes for 5 years. Hypertension should be screened for in T1DM patients by measuring blood pressure at each routine visit. Dyslipidemia in T1DM patients is important and patients should be screened if there is a family history of hypercholesterolemia or a cardiovascular event before the age of 55 years exists or if family history is unknown. Retinopathy is another important complication of diabetes and patients should be subjected to an initial dilated and comprehensive eye examination. Basic diabetes training should be provided for school staff, and they should be assigned with responsibilities for the care of diabetic children. Self-management should be allowed at all school settings for students.

  1. The Genetic Architecture of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Samuel T Jerram

    2017-08-01

    Full Text Available Type 1 diabetes (T1D is classically characterised by the clinical need for insulin, the presence of disease-associated serum autoantibodies, and an onset in childhood. The disease, as with other autoimmune diseases, is due to the interaction of genetic and non-genetic effects, which induce a destructive process damaging insulin-secreting cells. In this review, we focus on the nature of this interaction, and how our understanding of that gene–environment interaction has changed our understanding of the nature of the disease. We discuss the early onset of the disease, the development of distinct immunogenotypes, and the declining heritability with increasing age at diagnosis. Whilst Human Leukocyte Antigens (HLA have a major role in causing T1D, we note that some of these HLA genes have a protective role, especially in children, whilst other non-HLA genes are also important. In adult-onset T1D, the disease is often not insulin-dependent at diagnosis, and has a dissimilar immunogenotype with reduced genetic predisposition. Finally, we discuss the putative nature of the non-genetic factors and how they might interact with genetic susceptibility, including preliminary studies of the epigenome associated with T1D.

  2. Celiac disease in type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Camarca Maria

    2012-03-01

    Full Text Available Abstract Celiac Disease (CD occurs in patients with Type 1 Diabetes (T1D ranging the prevalence of 4.4-11.1% versus 0.5% of the general population. The mechanism of association of these two diseases involves a shared genetic background: HLA genotype DR3-DQ2 and DR4-DQ8 are strongly associated with T1D, DR3-DQ2 with CD. The classical severe presentation of CD rarely occurs in T1D patients, but more often patients have few/mild symptoms of CD or are completely asymptomatic (silent CD. In fact diagnosis of CD is regularly performed by means of the screening in T1D patients. The effects of gluten-free diet (GFD on the growth and T1D metabolic control in CD/T1D patient are controversial. Regarding of the GFD composition, there is a debate on the higher glycaemic index of gluten-free foods respect to gluten-containing foods; furthermore GFD could be poorer of fibers and richer of fat. The adherence to GFD by children with CD-T1D has been reported generally below 50%, lower respect to the 73% of CD patients, a lower compliance being more frequent among asymptomatic patients. The more severe problems of GFD adherence usually occur during adolescence when in GFD non compliant subjects the lowest quality of life is reported. A psychological and educational support should be provided for these patients.

  3. [NARCOLEPSY WITH CATAPLEXY: TYPE 1 NARCOLEPSY].

    Science.gov (United States)

    Dauvilliers, Yves; Lopez, Régis

    2016-06-01

    Narcolepsy with cataplexy or narcolepsy type 1 in a rare, disabling sleep disorder, with a prevalence of 20 to 30 per 100,000. Its onset peaks in the second decade. The main features are excessive daytime sleepiness and cataplexy or sudden less of muscle tone triggered by emotional situations. Other less consistent symptoms include hypnagogic hallucinations, sleep paralysis, disturbed nighttime sleep, and weight gain. Narcolepsy with cataplexy remains a clinical diagnosis but nighttime and daytime polysomnography (multiple sleep latency tests) are useful to document mean sleep latency below 8 min and at least two sleep-onset REM periods. HLA typing shows an association with HLA DQB1*0602 in more than 92% of cases but was not included in the new diagnostic criteria. In contrast, a low hypocretin-1/orexin-A levels (values below 110 pg/mL) in the cerebrospinal fluid was highly specific for narcolepsy with cataplexy and was included in the recent diagnostic criteria for narcolepsy. The deficiency of the hypocretin system is well-established in human narcoleptics with a reduction of cerebrospinal fluid hypocretin levels in relation with an early loss of hypocretin neurons. The cause of human narcolepsy remains unknown, however an autoimmune process in most probable acting on a highly genetic background with environmental factors such as streptococcal infections, and H1N1 AS03-adjuvanted vaccine named Pandemrix.

  4. Stem Cell Treatment for Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Ming eLi

    2014-03-01

    Full Text Available Type 1 diabetes mellitus (T1DM is a common chronic disease in children, characterized by a loss of  cells, which results in defects in insulin secretion and hyperglycemia. Chronic hyperglycemia causes diabetic complications, including diabetic nephropathy, neuropathy and retinopathy. Curative therapies mainly include diet and insulin administration. Although hyperglycemia can be improved by insulin administration, exogenous insulin injection cannot successfully mimic the insulin secretion from normal  cells, which keeps blood glucose levels within the normal range all the time. Islet and pancreas transplantation achieves better glucose control, but there is a lack of organ donors. Cell based therapies have also been attempted to treat T1DM. Stem cells such as embryonic stem cells, induced pluripotent stem cells and tissue stem cells (TSCs such as bone marrow-, adipose tissue- and cord blood-derived stem cells, have been shown to generate insulin-producing cells. In this review, we summarize the most-recently available information about T1DM and the use of TSCs to treat T1DM.

  5. Pregnancy in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Colstrup, Miriam; Mathiesen, Elisabeth; Damm, Peter

    2013-01-01

    Abstract Objective: In 1989 the St. Vincent declaration set a five-year target for approximating outcomes of pregnancies in women with diabetes to those of the background population. We investigated and quantified the risk of adverse pregnancy outcomes in pregnant women with type 1 diabetes (T1DM......) to evaluate if the goals of the 1989 St. Vincent Declaration have been obtained concerning foetal and neonatal complications. Methods: Twelve population-based studies published within the last 10 years with in total 14 099 women with T1DM and 4 035 373 women from the background population were identified....... The prevalence of four foetal and neonatal complications was compared. Results: In women with T1DM versus the background population, congenital malformations occurred in 5.0% (2.2-9.0) (weighted mean and range) versus 2.1% (1.5-2.9), relative risk (RR) = 2.4, perinatal mortality in 2.7% (2.0-6.6) versus 0.72% (0...

  6. Altered Immune Regulation in Type 1 Diabetes

    Science.gov (United States)

    Zóka, András; Műzes, Györgyi; Somogyi, Anikó; Varga, Tímea; Szémán, Barbara; Al-Aissa, Zahra; Hadarits, Orsolya; Firneisz, Gábor

    2013-01-01

    Research in genetics and immunology was going on separate strands for a long time. Type 1 diabetes mellitus might not be characterized with a single pathogenetic factor. It develops when a susceptible individual is exposed to potential triggers in a given sequence and timeframe that eventually disarranges the fine-tuned immune mechanisms that keep autoimmunity under control in health. Genomewide association studies have helped to understand the congenital susceptibility, and hand-in-hand with the immunological research novel paths of immune dysregulation were described in central tolerance, apoptotic pathways, or peripheral tolerance mediated by regulatory T-cells. Epigenetic factors are contributing to the immune dysregulation. The interplay between genetic susceptibility and potential triggers is likely to play a role at a very early age and gradually results in the loss of balanced autotolerance and subsequently in the development of the clinical disease. Genetic susceptibility, the impaired elimination of apoptotic β-cell remnants, altered immune regulatory functions, and environmental factors such as viral infections determine the outcome. Autoreactivity might exist under physiologic conditions and when the integrity of the complex regulatory process is damaged the disease might develop. We summarized the immune regulatory mechanisms that might have a crucial role in disease pathology and development. PMID:24285974

  7. Altered Immune Regulation in Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    András Zóka

    2013-01-01

    Full Text Available Research in genetics and immunology was going on separate strands for a long time. Type 1 diabetes mellitus might not be characterized with a single pathogenetic factor. It develops when a susceptible individual is exposed to potential triggers in a given sequence and timeframe that eventually disarranges the fine-tuned immune mechanisms that keep autoimmunity under control in health. Genomewide association studies have helped to understand the congenital susceptibility, and hand-in-hand with the immunological research novel paths of immune dysregulation were described in central tolerance, apoptotic pathways, or peripheral tolerance mediated by regulatory T-cells. Epigenetic factors are contributing to the immune dysregulation. The interplay between genetic susceptibility and potential triggers is likely to play a role at a very early age and gradually results in the loss of balanced autotolerance and subsequently in the development of the clinical disease. Genetic susceptibility, the impaired elimination of apoptotic β-cell remnants, altered immune regulatory functions, and environmental factors such as viral infections determine the outcome. Autoreactivity might exist under physiologic conditions and when the integrity of the complex regulatory process is damaged the disease might develop. We summarized the immune regulatory mechanisms that might have a crucial role in disease pathology and development.

  8. The geoepidemiology of type 1 diabetes.

    Science.gov (United States)

    Borchers, Andrea T; Uibo, Raivo; Gershwin, M E

    2010-03-01

    Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by absolute insulin deficiency resulting from the progressive immune-mediated destruction of pancreatic islet beta cells. It is thought to be triggered by as yet unidentified environmental factors in genetically susceptible individuals, the major genetic contribution coming from loci within the HLA complex, in particular HLA class II. The worldwide incidence of T1D varies by at least 100-fold, being highest in Finland and Sardinia (Italy) and lowest in Venezuela and China. The incidence has been increasing worldwide at an annual rate of approximately 3%. While genetic factors are thought to explain some of the geographic variability in T1D occurrence, they cannot account for its rapidly increasing frequency. Instead, the declining proportion of newly diagnosed children with high-risk genotypes suggests that environmental pressures are now able to trigger T1D in genotypes that previously would not have developed the disease during childhood. Although comparisons between countries and regions with low and high-incidence rates have suggested that higher socioeconomic status and degree of urbanization are among the environmental factors that play a role in the rising incidence of T1D, the findings are too inconsistent to allow firm conclusions. Morbidity and mortality as well as causes of death also show considerable geographic variation. While glycemic control has been identified as a major predictor of the micro- and macrovascular complications of T1D and shows considerable geographical variability, it does not appear to be the only factor involved in the regional differences in complication rates. The role of genetics in susceptibility to nephropathy, retinopathy and other diabetic complications largely remains to be explored. 2009 Elsevier B.V. All rights reserved.

  9. [Neuropsychological performance in neurofibromatosis type 1].

    Science.gov (United States)

    Hernández Del Castillo, Lilia; Martínez Bermejo, Antonio; Portellano Pérez, José Antonio; Tirado Requero, Pilar; Garriz Luis, Alexandra; Velázquez Fragua, Ramón

    2017-08-01

    Neurofibromatosis type 1 (NF1) is a genetic disorder with various clinical manifestations that affect the peripheral and central nervous system, as well as the skin, bones and endocrine and vascular system. There is still insufficient knowledge of neuropsychological effects of NF1 on children, and there is some controversy about the cognitive deficits that defines the cognitive profile of patients affected by this disorder. In this study an analysis is made of the neuropsychological performance of a group of patients affected by NF1, compared with a control group of healthy children. A comparison was made between the neuropsychological performance of a group of 23 boys and girls with a mean age of 8.7 years (+/-1.39) and diagnosed with NF1, and a control group consisting of 21 healthy children, with mean age of 8.9 years (+/- 1.41) and with similar socio-demographic characteristics. The Wechsler Intelligence Scale for Children (WISC) was applied to evaluate the subjects of both groups. The group of patients affected with NF1 showed a lower performance in every primary index of WISC IV: Verbal Comprehension Index, Fluid Reasoning Index, Working Memory Index, Processing Speed Index, and full Scale IQ. Only in two subscales were no statistically significant differences observed: similarities and coding. The results show subtle and generalised neuropsychological alterations in the sample of children affected with NF1, which affect most of cognitive domains that have been evaluated. Proper specific and early neuropsychological treatment should be provided in order to prevent the high risk for these children of presenting learning difficulties and school failure. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Type 1 diabetes in India: Overall insights.

    Science.gov (United States)

    Das, Ashok Kumar

    2015-04-01

    Type 1 diabetes mellitus (T1DM) is also on increase like type 2 diabetes, even though not in the same proportion, but still with a trend of 3-5% increase/year. India has three new cases of T1DM/100,000 children of 0-14 years. Three sets of prevalence data shows 17.93 cases/100,000 children in Karnataka, 3.2 cases/100,000 children in Chennai, and 10.2 cases/100,000 children in Karnal (Haryana). T1DM may be autoimmune or idiopathic in nature and is present in 9% cases of insulin deficiency. T1DM is primarily caused by genetic factors, environmental factors, and disorder of the immune regulatory mechanism. A combination of all these three factors causes autoimmune disease, which may ultimately result in the destruction of pancreatic beta cells leading to hyperglycemia, ketoacidosis and potentially death, if not treated with insulin. Prediabetes is the phase before the onset of T1DM, which provides a window of opportunity for early intervention. All available interventions including steroids, immunosuppressants, and cyclosporins can be possibly applied during the prediabetes phase. The treatment goals for T1DM are simple and include maintaining near normal blood glucose levels and avoiding long-term complications, which is a constant juggle between insulin and maintaining an appropriate lifestyle. The Indian Council of Medical Research funded Registry of People with diabetes in India with young age at onset (YDR) was started in the year 2006 with 10 collaborating centres across India. This registry is focusing on to provide an overview of diabetes in the young.

  11. Type 1 diabetes in India: Overall insights

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Das

    2015-01-01

    Full Text Available Type 1 diabetes mellitus (T1DM is also on increase like type 2 diabetes, even though not in the same proportion, but still with a trend of 3-5% increase/year. India has three new cases of T1DM/100,000 children of 0-14 years. Three sets of prevalence data shows 17.93 cases/100,000 children in Karnataka, 3.2 cases/100,000 children in Chennai, and 10.2 cases/100,000 children in Karnal (Haryana.T1DM may be autoimmune or idiopathic in nature and is present in 9% cases of insulin deficiency. T1DM is primarily caused by genetic factors, environmental factors, and disorder of the immune regulatory mechanism. A combination of all these three factors causes autoimmune disease, which may ultimately result in the destruction of pancreatic beta cells leading to hyperglycemia, ketoacidosis and potentially death, if not treated with insulin. Prediabetes is the phase before the onset of T1DM, which provides a window of opportunity for early intervention. All available interventions including steroids, immunosuppressants, and cyclosporins can be possibly applied during the prediabetes phase. The treatment goals for T1DM are simple and include maintaining near normal blood glucose levels and avoiding long-term complications, which is a constant juggle between insulin and maintaining an appropriate lifestyle. The Indian Council of Medical Research funded Registry of People with diabetes in India with young age at onset (YDR was started in the year 2006 with 10 collaborating centres across India. This registry is focusing on to provide an overview of diabetes in the young.

  12. Adenoviral vectors expressing fusogenic membrane glycoproteins activated via matrix metalloproteinase cleavable linkers have significant antitumor potential in the gene therapy of gliomas.

    Science.gov (United States)

    Allen, Cory; McDonald, Cari; Giannini, Caterina; Peng, Kah Whye; Rosales, Gabriela; Russell, Stephen J; Galanis, Evanthia

    2004-11-01

    Fusogenic membrane glycoproteins (FMG) such as the gibbon ape leukemia virus envelope (GALV) glycoprotein are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. Transfection of glioma cell lines with FMG expression constructs results in fusion with massive syncytia formation followed by cytotoxic cell death. Nevertheless, ubiquitous expression of the GALV receptor, Pit-1, makes targeting desirable in order to increase the specificity of the observed cytopathic effect. Here we report on use of matrix metalloproteinase (MMP)-cleavable linkers to target the cytotoxicity of FMG-expressing adenoviral vectors against gliomas. Replication-defective adenoviruses (Ad) were constructed expressing the hyperfusogenic version of the GALV glycoprotein linked to a blocking ligand (C-terminal extracellular domain of CD40 ligand) through either an MMP-cleavable linker (AdM40) or a non-cleavable linker (AdN40). Both viruses also co-expressed the green fluorescent protein (GFP) via an internal ribosomal entry site. The glioma cell lines U87, U118, and U251 characterized by zymography and MMP-2 activity assay as high, medium and low MMP expressors, respectively, the MMP-poor cell lines TE671 and normal human astrocytes were infected with AdM40 and AdN40 at different multiplicities of infection (MOIs) from 1-30. Fusion was quantitated by counting both number and size of syncytia. Infection of these cell lines with AdN40 did not result in fusion or cytotoxic cell death, despite the presence of infection, as demonstrated by GFP positivity, therefore indicating that the displayed CD40 ligand blocked GALV-induced fusion. Fusion was restored after infection of glioma cells with AdM40 at an MOI as low as 1 to an extent dependent on MMP expression and coxsackie adenovirus receptor (CAR) expression in the specific cell line. Western immunoblotting demonstrated the presence of the cleaved CD40 ligand in the supernatant of fused glioma cells. Use of the MMP

  13. Equid herpesvirus type 1 activates platelets.

    Directory of Open Access Journals (Sweden)

    Tracy Stokol

    Full Text Available Equid herpesvirus type 1 (EHV-1 causes outbreaks of abortion and neurological disease in horses. One of the main causes of these clinical syndromes is thrombosis in placental and spinal cord vessels, however the mechanism for thrombus formation is unknown. Platelets form part of the thrombus and amplify and propagate thrombin generation. Here, we tested the hypothesis that EHV-1 activates platelets. We found that two EHV-1 strains, RacL11 and Ab4 at 0.5 or higher plaque forming unit/cell, activate platelets within 10 minutes, causing α-granule secretion (surface P-selectin expression and platelet microvesiculation (increased small events double positive for CD41 and Annexin V. Microvesiculation was more pronounced with the RacL11 strain. Virus-induced P-selectin expression required plasma and 1.0 mM exogenous calcium. P-selectin expression was abolished and microvesiculation was significantly reduced in factor VII- or X-deficient human plasma. Both P-selectin expression and microvesiculation were re-established in factor VII-deficient human plasma with added purified human factor VIIa (1 nM. A glycoprotein C-deficient mutant of the Ab4 strain activated platelets as effectively as non-mutated Ab4. P-selectin expression was abolished and microvesiculation was significantly reduced by preincubation of virus with a goat polyclonal anti-rabbit tissue factor antibody. Infectious virus could be retrieved from washed EHV-1-exposed platelets, suggesting a direct platelet-virus interaction. Our results indicate that EHV-1 activates equine platelets and that α-granule secretion is a consequence of virus-associated tissue factor triggering factor X activation and thrombin generation. Microvesiculation was only partly tissue factor and thrombin-dependent, suggesting the virus causes microvesiculation through other mechanisms, potentially through direct binding. These findings suggest that EHV-1-induced platelet activation could contribute to the thrombosis

  14. The structure of myristoylated Mason-Pfizer monkey virus matrix protein and the role of phosphatidylinositol-(4,5)-bisphosphate in its membrane binding.

    Science.gov (United States)

    Prchal, Jan; Srb, Pavel; Hunter, Eric; Ruml, Tomáš; Hrabal, Richard

    2012-10-26

    We determined the solution structure of myristoylated Mason-Pfizer monkey virus matrix protein by NMR spectroscopy. The myristoyl group is buried inside the protein and causes a slight reorientation of the helices. This reorientation leads to the creation of a binding site for phosphatidylinositols. The interaction between the matrix protein and phosphatidylinositols carrying C(8) fatty acid chains was monitored by observation of concentration-dependent chemical shift changes of the affected amino acid residues, a saturation transfer difference experiment and changes in (31)P chemical shifts. No differences in the binding mode or affinity were observed with differently phosphorylated phosphatidylinositols. The structure of the matrix protein-phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)] complex was then calculated with HADDOCK software based on the intermolecular nuclear Overhauser enhancement contacts between the ligand and the matrix protein obtained from a (13)C-filtered/(13)C-edited nuclear Overhauser enhancement spectroscopy experiment. PI(4,5)P(2) binding was not strong enough for triggering of the myristoyl-switch. The structural changes of the myristoylated matrix protein were also found to result in a drop in the oligomerization capacity of the protein. Copyright © 2012. Published by Elsevier Ltd.

  15. Pregnancy outcome in type 1 diabetic women with microalbuminuria

    DEFF Research Database (Denmark)

    Ekbom, P; Damm, P; Feldt-Rasmussen, B

    2001-01-01

    To determine the influence of microalbuminuria on pregnancy outcome in women with type 1 diabetes.......To determine the influence of microalbuminuria on pregnancy outcome in women with type 1 diabetes....

  16. Postprandial hyperinsulinaemic hypoglycaemia and type 1 diabetes mellitus

    OpenAIRE

    Poon, Myra; Hussain, Khalid

    2009-01-01

    A patient with severe postprandial hyperinsulinaemic hypoglycaemia (PPHH) for 4 years developed type 1 diabetes mellitus. She had no insulin or insulin receptor antibodies but was positive for islet cell and glutamic acid decarboxylase (GAD) antibodies. PPHH prior to the onset of type 1 diabetes mellitus has not been previously described and may be a prodrome of type 1 diabetes mellitus.

  17. 27 CFR 555.207 - Construction of type 1 magazines.

    Science.gov (United States)

    2010-04-01

    ... constructed of, or covered with, a nonsparking material. (3) Wood frame wall construction. The exterior of... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Construction of type 1... Construction of type 1 magazines. A type 1 magazine is a permanent structure: a building, an igloo or “Army...

  18. Tests for genetic interactions in type 1 diabetes

    DEFF Research Database (Denmark)

    Morahan, Grant; Mehta, Munish; James, Ian

    2011-01-01

    Interactions between genetic and environmental factors lead to immune dysregulation causing type 1 diabetes and other autoimmune disorders. Recently, many common genetic variants have been associated with type 1 diabetes risk, but each has modest individual effects. Familial clustering of type 1...... diabetes has not been explained fully and could arise from many factors, including undetected genetic variation and gene interactions....

  19. Observation of Fermi Arc Surface States Induced by Organic Memristive/Memcapacitive Devices with a Double-Helical Polarized Single-Wall Nanotube Membrane for Direct Chelating with Matrix Matelloproteinase-2

    Directory of Open Access Journals (Sweden)

    E. T. CHEN

    2017-07-01

    Full Text Available Matrix Matelloproteinase-2 (MMP-2 plays a key role in many diseases. A new type of dual-functioning device was developed for fast, direct ultrasensitive detection of MMP-2. We report a memristive/memcapacitive device with vertex double-helical polarized biomimetic protein nanotubules forming double membranes with potential gradient mimicking mitochondria’s inner double membrane has developed. We also report Fermi arcs with nodes on the surface of the nanostructured membrane was observed at the first time by using a 3D real-time - energy-current dynamic mapping method based on data obtained from the Cyclic Voltammetry (CV method. The memristive/memcapacitive device comprises a cross- linked organic polymer having single-wall cross-bar polarized nanotube self-assembling membrane (SAM on a gold chip, under an applied potential, a pair of vertex double- helical circular current flow induced the Fermi arcs states occurrence and these Fermi arcs promoted a direct chelating with zinc ions of the MMP-2 to become possible without any antibody, tracer, or reagent used at room temperature was accomplished. We observed the pair of Dirac Cones became alignment and strengthened with each other in the presence of MMP-2 compared without MMP-2. The MMP-2 can be detected with ag/mL level sensitivity and the value of Detection of Limits (DOL reached orders of magnitude lower than published reports with simplified procedures by a Chronoamperometry (CA method and a Double Step Chronopotentiometry (DSCPO method using NIST SRM 965A standard human serum, respectively. The results show a feasible application for developing the commercial fast and real-time MMP monitoring devices for various diseases.

  20. Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture

    KAUST Repository

    Sabetghadam, Anahid

    2018-03-24

    To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25wt% of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10%, while for Pebax they were enhanced to 25 and 18%, respectively. The observed differences in membrane performance in the separation of CO from N are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases.

  1. Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture

    KAUST Repository

    Sabetghadam, Anahid; Liu, Xinlei; Benzaqui, Marvin; Gkaniatsou, Effrosyni; Orsi, Angelica; Lozinska, Magdalena M.; Sicard, Clemence; Johnson, Timothy; Steunou, Nathalie; Wright, Paul A.; Serre, Christian; Gascon, Jorge; Kapteijn, Freek

    2018-01-01

    To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25wt% of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10%, while for Pebax they were enhanced to 25 and 18%, respectively. The observed differences in membrane performance in the separation of CO from N are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases.

  2. Decision-making in diabetes mellitus type 1.

    Science.gov (United States)

    Rustad, James K; Musselman, Dominique L; Skyler, Jay S; Matheson, Della; Delamater, Alan; Kenyon, Norma S; Cáceda, Ricardo; Nemeroff, Charles B

    2013-01-01

    Decreased treatment adherence in patients with diabetes mellitus type 1 (type 1 DM) may reflect impairments in decision-making and underlying associated deficits in working memory and executive functioning. Other factors, including comorbid major depression, may also interfere with decision-making. The authors sought to review the clinically relevant characteristics of decision-making in type 1 DM by surveying the literature on decision-making by patients with type 1 DM. Deficiencies in decision-making in patients with type 1 DM or their caregivers contribute to treatment nonadherence and poorer metabolic control. Animal models of type 1 DM reveal deficits in hippocampal-dependent memory tasks, which are reversible with insulin. Neurocognitive studies of patients with type 1 DM reveal lowered performance on ability to apply knowledge to solve problems in a new situation and acquired scholarly knowledge, psychomotor efficiency, cognitive flexibility, visual perception, speed of information-processing, and sustained attention. Other factors that might contribute to poor decision-making in patients with type 1 DM, include "hypoglycemia unawareness" and comorbid major depression (given its increased prevalence in type 1 DM). Future studies utilizing novel treatment strategies to help patients with type 1 DM make better decisions about their disease may improve their glycemic control and quality of life, while minimizing the impact of end-organ disease.

  3. Influence of Filler Pore Structure and Polymer on the Performance of MOF-based Mixed Matrix Membranes for CO2 Capture.

    Science.gov (United States)

    Sabetghadam, Anahid; Liu, Xinlei; Benzaqui, Marvin; Gkaniatsou, Effrosyni; Orsi, Angelica; Lozinska, Magdalena M; Sicard, Clemence; Johnson, Timothy; Steunou, Nathalie; Wright, Paul A; Serre, Christian; Gascon, Jorge; Kapteijn, Freek

    2018-03-24

    In order to gain insight into the influence of metal-organic framework (MOF) filler and polymer on membrane performance, eight different composites are studied by combining four MOFs and two polymers. MOF materials (NH2-MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, while two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were deliberately selected as matrices. The best performing MOF-polymer composites were prepared by loading 25 wt.% of MIL-96(Al) as filler which improved the permeability and selectivity of 6FDA-DAM up to 32% and 10%, while for Pebax this enhancement was 25% and 18%, respectively. The observed differences in membrane performance in the separation of CO2 from N2 are explained on the basis of gas solubility, diffusivity properties and compatibility between the filler and polymer phases. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Interbirth interval is associated with childhood type 1 diabetes risk

    DEFF Research Database (Denmark)

    Cardwell, Chris R; Svensson, Jannet; Waldhoer, Thomas

    2012-01-01

    to calculate pooled odds ratios (ORs) and investigate heterogeneity between studies. Overall, 2,787 children with type 1 diabetes were included. There was a reduction in the risk of childhood type 1 diabetes in children born to mothers after interbirth intervals...... of childhood type 1 diabetes has not been investigated. A secondary analysis of 14 published observational studies of perinatal risk factors for type 1 diabetes was conducted. Risk estimates of diabetes by category of interbirth interval were calculated for each study. Random effects models were used...

  5. Stigma Perceived and Experienced by Adults with Type 1 Diabetes

    DEFF Research Database (Denmark)

    Hansen, Ulla Møller; Willaing, Ingrid; Ventura, Adriana D

    2017-01-01

    OBJECTIVES: We aimed to (a) culturally and linguistically adapt the Type 1 Diabetes Stigma Assessment Scale (DSAS-1) from English (for Australia) into Danish and (b) examine psychometric properties of the measure among Danish adults with type 1 diabetes. METHODS: We performed a forward......-backward translation, face validity interviews with experts and cognitive debriefing of the Danish version (DSAS-1 DK) with ten adults from the target group. The DSAS-1 DK was then completed by 1594 adults with type 1 diabetes. Electronic clinical records provided age, diabetes duration, diabetes-related complications...... to advance research into the stigma perceived and experienced by adults with type 1 diabetes in a Danish context....

  6. Helicobacter pylori-elicited induction in gastric mucosal matrix metalloproteinase-9 (MMP-9) release involves ERK-dependent cPLA2 activation and its recruitment to the membrane-localized Rac1/p38 complex.

    Science.gov (United States)

    Slomiany, B L; Slomiany, A

    2016-06-01

    Matrix metalloproteinases (MMPs) are a family of endopeptidases implicated in a wide rage of degenerative and inflammatory diseases, including Helicobacter pylori-associated gastritis, and gastric and duodenal ulcer. As gastric mucosal inflammatory responses to H. pylori are characterized by the rise in MMP-9 production, as well as the induction in mitogen-activated protein kinase (MAPK) and Rac1 activation, we investigated the role of Rac1/MAPK in the processes associated with the release of MMP-9. We show that H. pylori LPS-elicited induction in gastric mucosal MMP-9 release is associated with MAPK, ERK and p38 activation, and occurs with the involvement of Rac1 and cytosolic phospholipase A2 (cPLA2). Further, we demonstrate that the LPS-induced MMP-9 release requires ERK-mediated phosphorylation of cPLA2 on Ser(505) that is essential for its membrane localization with Rac1, and that this process necessitates p38 participation. Moreover, we reveal that the activation and membrane translocation of p38 to the Rac1-GTP complex plays a pivotal role in cPLA2-dependent enhancement in MMP-9 release. Hence, our findings provide a strong evidence for the role of ERK/cPLA2 and Rac1/p38/cPLA2 cascade in H. pylori LPS-induced up-regulation in gastric mucosal MMP-9 release.

  7. Lymphocyte apoptosis in the pathogenesis of type 1 diabetes mellitus

    African Journals Online (AJOL)

    EL-HAKIM

    biochemical features.2 It is a coordinated series of events for the ... sex matched subjects with no clinical or laboratory signs or family history of ... Keywords: lymphocyte apoptosis; CD95 system; type 1 DM; prediabetes. Eman M. ..... percentage among complicated and non-complicated cases of type-1 diabetes mellitus.

  8. Management of Type 1 Diabetes in Schools: Whose Responsibility?

    Science.gov (United States)

    Mandali, Swarna L.; Gordon, Theresa A.

    2009-01-01

    The Centers for Disease Control and Prevention (2008) reports that approximately 0.2% of all persons under the age of 20 have been diagnosed with either type 1 or type 2 diabetes. This represents 186,300 children and young adults. Type 1 diabetes has traditionally been a disease of children and adolescents. Although type 2 diabetes has in the past…

  9. Coexistence of coeliac disease and type 1 diabetes

    OpenAIRE

    Szaflarska-Popławska, Anna

    2014-01-01

    There is a selective review of the literature concerning the coexistence of coeliac disease and type 1 diabetes mellitus. This review focuses on the principles of serological tests towards coeliac disease in patients with type 1 diabetes mellitus and metabolic control measures as a result of a gluten-free diet.

  10. Partial sleep restriction decreases insulin sensitivity in type 1 diabetes

    NARCIS (Netherlands)

    Donga, Esther; van Dijk, Marieke [Leiden Univ., LUMC; van Dijk, J. Gert; Biermasz, Nienke R.; Lammers, Gert-Jan; van Kralingen, Klaas; Hoogma, Roel P. L. M.; Corssmit, Eleonora P. M.; Romijn, Johannes A.

    2010-01-01

    Sleep restriction results in decreased insulin sensitivity and glucose tolerance in healthy subjects. We hypothesized that sleep duration is also a determinant of insulin sensitivity in patients with type 1 diabetes. We studied seven patients (three men, four women) with type 1 diabetes: mean age 44

  11. Breast-feeding and childhood-onset type 1 diabetes

    DEFF Research Database (Denmark)

    Cardwell, Chris R; Stene, Lars C; Ludvigsson, Johnny

    2012-01-01

    To investigate if there is a reduced risk of type 1 diabetes in children breastfed or exclusively breastfed by performing a pooled analysis with adjustment for recognized confounders.......To investigate if there is a reduced risk of type 1 diabetes in children breastfed or exclusively breastfed by performing a pooled analysis with adjustment for recognized confounders....

  12. Human leukocyte antigen (HLA) polymorphism and type 1 diabetes ...

    African Journals Online (AJOL)

    Insulin-dependent diabetes mellitus or type 1 diabetes is an autoimmune multifactorial disease which has a great socio-economic impact. In Morocco, less is known about the contribution of Human leukocyte antigen (HLA) alleles to type 1 diabetes susceptibility. Our study focused on evaluating the distribution of class II ...

  13. Type 1,1-operators defined by vanishing frequency modulation

    DEFF Research Database (Denmark)

    Johnsen, Jon

    This paper presents a general definition of pseudo-differential operators of type 1,1; the definition is shown to be the largest one that is both compatible with negligible operators and stable under vanishing frequency modulation. Elaborating counter-examples of Ching andHörmander, type 1...

  14. The Effect of Type-1 Error on Deterrence

    DEFF Research Database (Denmark)

    Lando, Henrik; Mungan, Murat C.

    2018-01-01

    According to a conventional view, type-1 error (wrongful conviction) is as detrimental to deterrence as type-2 error (wrongful acquittal), because type-1 error lowers the pay-off from acting within the law. This view has led to the claim that the pro-defendant bias of criminal procedure, and its ...

  15. Efficacy of standardised herbal extracts in type 1 diabetes - an ...

    African Journals Online (AJOL)

    In the present study, the hypoglycemic activity of Withania somnifera Dunal, Allium sativum Linn., Gymnema sylvestre (Retz.) Schult, Ferula foetida (Bunge.) Reg. and Murraya koenigii (L.) Spreng. extracts have been studied in an experimental model of type 1 diabetes. Type 1 diabetes was induced in albino rats by a single ...

  16. The epidemiology and pathogenesis of type 1 diabetes mellitus in ...

    African Journals Online (AJOL)

    Type 1 diabetes is a serious, debilitating disease, with life-threatening complications, and the financial burden associated with the management of this disease is enormous. Early diagnosis and intervention can improve morbidity and mortality. Unfortunately, in Africa, type 1 diabetes is poorly characterised, and there is ...

  17. Audit on stillbirths in women with pregestational type 1 diabetes

    DEFF Research Database (Denmark)

    Lauenborg, Jeannet; Mathiesen, Elisabeth Reinhardt; Ovesen, Per Glud

    2003-01-01

    To audit stillbirth cases in women with type 1 diabetes to search for specific characteristics in order to improve antenatal care and treatment.......To audit stillbirth cases in women with type 1 diabetes to search for specific characteristics in order to improve antenatal care and treatment....

  18. Experimental Therapy Shows Promise for Type 1 Diabetes

    Science.gov (United States)

    ... triggers cells to take up sugar from the blood. In type 1 diabetes, the immune system The cells and tissues that ... people to eat or drink to raise their blood sugar levels. However, many people with type 1 diabetes can’t tell when their blood sugar is ...

  19. Type 1 diabetes: New horizons in prediction and prevention.

    Science.gov (United States)

    Razack, Natasha N; Wherrett, Diane K

    2005-01-01

    Significant advances have been made in our understanding of the pathogenesis of type 1 diabetes and our ability to predict risk for the condition. This knowledge is being used to develop new and innovative strategies to prevent type 1 diabetes or to prevent further destruction of beta cells in those who are newly diagnosed. Several multicentre studies are underway investigating the natural history of the disease, the genetics behind the disease and ways to stop the autoimmune reaction against beta cells (Type 1 Diabetes TrialNet, Type 1 Diabetes Genetics Consortium and the Trial to Reduce Diabetes in the Genetically at Risk [TRIGR] Study Group). The stage is set to find an agent or strategy to prevent type 1 diabetes or to preserve the residual beta cell mass in new-onset patients.

  20. Prelabor Cesarean Section and Risk of Childhood Type 1 Diabetes

    DEFF Research Database (Denmark)

    Clausen, Tine Dalsgaard; Bergholt, Thomas; Eriksson, Frank

    2016-01-01

    BACKGROUND: Unfavorable conditions associated with cesarean section may influence the risk of type 1 diabetes in offspring, but results from studies are conflicting. We aimed to evaluate the association between prelabor cesarean section and risk of childhood type 1 diabetes. METHODS: A Danish...... nationwide cohort study followed all singletons born during 1982-2010. Five national registers provided information on mode of delivery, outcome, and confounders. The risk of childhood type 1 diabetes with onset before the age of 15 years was assessed by Cox regression. A total of 1,760,336 singletons...... contributed 20,436,684 person-years, during which 4,400 were diagnosed with childhood type 1 diabetes. RESULTS: The hazard ratio for childhood type 1 diabetes was increased in children delivered by prelabor cesarean section compared with vaginal delivery when adjusted for year of birth, parity, sex, parental...

  1. Fulminant type 1 diabetes mellitus: a case report

    Science.gov (United States)

    Yunir, E.; Nenfiati

    2018-03-01

    Type 1 diabetes mellitus is a metabolic disease caused by insulin deficiency that results from destruction of β-cells in the pancreas. Based on American Diabetes Association, there are two types of type 1 diabetes mellitus: type 1A (autoimmune) and 1B (idiopathic). In this case, we are presenting a new archetype of type 1 diabetes named fulminant type 1 diabetes mellitus. This disease results from quick destruction of β-cells byanautoimmune mechanism. The manifestation of this disease consists of unspecific flu-like symptoms, abdominal symptoms, to specific hyperglycemia symptoms such as fatigue, malaise, change in mental status that are attributable to high blood glucose and ketosis. Laboratory examination reveals high blood glucose, normal glycosylated hemoglobin, ketosis or ketoacidosis, potassium depletion and elevation of liver function tests. Treatment consists of intravenous infusion followed by insulin injection for blood glucose control, followed by treatment of metabolic derangements such as acid-base and electrolyte disorder.

  2. Reduction of /sup 51/Cr-permeability of tissue culture cells by infection with herpes simplex virus type 1

    Energy Technology Data Exchange (ETDEWEB)

    Schlehofer, J.R.; Habermehl, K.O.; Diefenthal, W.; Hampl, H.

    1979-01-01

    Infection of different strains of tissue culture cells with herpes simplex virus type 1(HSV-1) resulted in a reduced /sup 51/Cr-permeability. A stability of the cellular membrane to Triton X-100, toxic sera and HSV-specific complement-mediated immune-cytolysis could be observed simultaneously. The results differed with respect to the cell strain used in the experiments.

  3. Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

    Directory of Open Access Journals (Sweden)

    Tianzhi Chen

    2016-09-01

    Full Text Available To investigate whether ocular albinism type 1 (OA1 is differentially expressed in the skin of mice with different coat colors and to determine its correlation with coat color establishment in mouse, the expression patterns and tissue distribution characterization of OA1 in the skin of mice with different coat colors were qualitatively and quantitatively analyzed by real-time quantitative PCR (qRT-PCR, immunofluorescence staining and Western blot. The qRT-PCR analysis revealed that OA1 mRNA was expressed in all mice skin samples tested, with the highest expression level in brown skin, a moderate expression level in black skin and the lowest expression level in gray skin. Positive OA1 protein bands were also detected in all skin samples by Western blot analysis. The relative expression levels of OA1 protein in both black and brown skin were significantly higher than that in gray skin, but there was no significant difference between black and brown mice. Immunofluorescence assays revealed that OA1 was mainly expressed in the hair follicle matrix, the inner and outer root sheath in the skin tissues with different coat colors. To get further insight into the important role of OA1 in the melanocytes’ pigmentation, we transfected the OA1 into mouse melanocytes and then detected the relative expression levels of pigmentation-related gene. Simultaneously, we tested the melanin content of melanocytes. As a result, the overexpression of OA1 significantly increased the expression levels of microphthalmia-associated transcription factor (MITF, tyrosinase (TYR, tyrosinase-related protein 1 (TRP1 and premelanosome protein (PMEL. However, the tyrosinase-related protein 2 (TRP2 level was attenuated. By contrast, the level of glycoprotein non-metastatic melanoma protein b (GPNMB was unaffected by OA1 overexpression. Furthermore, we observed a significant increase in melanin content in mouse melanocyte transfected OA1. Therefore, we propose that OA1 may

  4. Distinct cell clusters touching islet cells induce islet cell replication in association with over-expression of Regenerating Gene (REG protein in fulminant type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Kaoru Aida

    Full Text Available BACKGROUND: Pancreatic islet endocrine cell-supporting architectures, including islet encapsulating basement membranes (BMs, extracellular matrix (ECM, and possible cell clusters, are unclear. PROCEDURES: The architectures around islet cell clusters, including BMs, ECM, and pancreatic acinar-like cell clusters, were studied in the non-diabetic state and in the inflamed milieu of fulminant type 1 diabetes in humans. RESULT: Immunohistochemical and electron microscopy analyses demonstrated that human islet cell clusters and acinar-like cell clusters adhere directly to each other with desmosomal structures and coated-pit-like structures between the two cell clusters. The two cell-clusters are encapsulated by a continuous capsule composed of common BMs/ECM. The acinar-like cell clusters have vesicles containing regenerating (REG Iα protein. The vesicles containing REG Iα protein are directly secreted to islet cells. In the inflamed milieu of fulminant type 1 diabetes, the acinar-like cell clusters over-expressed REG Iα protein. Islet endocrine cells, including beta-cells and non-beta cells, which were packed with the acinar-like cell clusters, show self-replication with a markedly increased number of Ki67-positive cells. CONCLUSION: The acinar-like cell clusters touching islet endocrine cells are distinct, because the cell clusters are packed with pancreatic islet clusters and surrounded by common BMs/ECM. Furthermore, the acinar-like cell clusters express REG Iα protein and secrete directly to neighboring islet endocrine cells in the non-diabetic state, and the cell clusters over-express REG Iα in the inflamed milieu of fulminant type 1 diabetes with marked self-replication of islet cells.

  5. Matrix theory

    CERN Document Server

    Franklin, Joel N

    2003-01-01

    Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.

  6. NHSBSP type 1 interval cancers: a scientifically valid grouping?

    International Nuclear Information System (INIS)

    Porter, G.J.R.; Evans, A.J.; Burrell, H.C.; Lee, A.H.S.; Chakrabarti, J.

    2007-01-01

    Aim: To assess whether there are differences in the pathological features or survival between the new National Health Service Breast Screening Programme (NHSBSP) interval cancer classification system category of type 1 interval cancers, and the previously used, separate categories of occult, unclassified, and true interval cancers. Materials and methods: The prognostic pathological features (grade, lymph node stage, size, vascular invasion, oestrogen receptor status, and histological type) and survival of 428 type 1 interval invasive breast cancers were analysed by subgroup (occult, unclassified and true interval). Results: Occult cancers compared with other type 1 interval cancers were of significantly lower grade [38 of 52 (73%) versus 151 of 340 (44%) grade 1 or 2, p = 0.0005], more likely to be smaller size [37 of 51 (73%) versus 158 of 341 (46%) <20 mm, p = 0.0003] and more frequently of lobular type at histology [14 of 42 (32%) versus 50 of 286 (17%), p = 0.03]. There was no significant difference in pathological features of unclassified tumours compared with other type 1 tumours. There was no significant survival difference between different type 1 subgroups (p = 0.12). Conclusion: The NHSBSP type 1 interval cancers are a heterogeneous grouping with markedly differing pathological features. However, no significant survival difference is seen between the different type 1 subgroups

  7. NHSBSP type 1 interval cancers: a scientifically valid grouping?

    Energy Technology Data Exchange (ETDEWEB)

    Porter, G.J.R. [Nottingham Breast Institute, City Hospital, Nottingham (United Kingdom)]. E-mail: garethporter@doctors.org.uk; Evans, A.J. [Nottingham Breast Institute, City Hospital, Nottingham (United Kingdom); Burrell, H.C. [Nottingham Breast Institute, City Hospital, Nottingham (United Kingdom); Lee, A.H.S. [Nottingham Breast Institute, City Hospital, Nottingham (United Kingdom); Chakrabarti, J. [Nottingham Breast Institute, City Hospital, Nottingham (United Kingdom)

    2007-03-15

    Aim: To assess whether there are differences in the pathological features or survival between the new National Health Service Breast Screening Programme (NHSBSP) interval cancer classification system category of type 1 interval cancers, and the previously used, separate categories of occult, unclassified, and true interval cancers. Materials and methods: The prognostic pathological features (grade, lymph node stage, size, vascular invasion, oestrogen receptor status, and histological type) and survival of 428 type 1 interval invasive breast cancers were analysed by subgroup (occult, unclassified and true interval). Results: Occult cancers compared with other type 1 interval cancers were of significantly lower grade [38 of 52 (73%) versus 151 of 340 (44%) grade 1 or 2, p = 0.0005], more likely to be smaller size [37 of 51 (73%) versus 158 of 341 (46%) <20 mm, p = 0.0003] and more frequently of lobular type at histology [14 of 42 (32%) versus 50 of 286 (17%), p = 0.03]. There was no significant difference in pathological features of unclassified tumours compared with other type 1 tumours. There was no significant survival difference between different type 1 subgroups (p = 0.12). Conclusion: The NHSBSP type 1 interval cancers are a heterogeneous grouping with markedly differing pathological features. However, no significant survival difference is seen between the different type 1 subgroups.

  8. [Endurance capabilities of triathlon competitors with type 1 diabetes mellitus].

    Science.gov (United States)

    Boehncke, S; Poettgen, K; Maser-Gluth, C; Reusch, J; Boehncke, W-H; Badenhoop, K

    2009-04-01

    Treatment of type 1 diabetes mellitus (DM) aims to prevent complications by strictly optimizing blood glucose levels. Although physical exercise is an important part of metabolic control, endurance sports are considered hazardous for patients with type 1 diabetes because of the extreme physiological stress they represent. To further elucidate the metabolic challenge this form of exercise presented we investigated the performance of triathlon competitors with type 1 diabetes. Ten patients (32-61 years) with type 1 diabetes (disease duration 2-35 years) were followed for three years, during which each year they participated in one triathlon long-distance competitions (2.4 miles swimming, 26.2 miles running and 112 miles cycling; Ironman Germany 2005-2007). Glucose, cortisol, aldosterone, renin, thyroid hormones, testosterone, growth hormone and catecholamines were measured in blood and saliva. Five non-diabetic competitors served as controls. The performance equalled those of age-matched healthy athletes. Several participants experienced hyperglycemia early in the bike leg, whereas all of them developed low blood glucose levels during the marathon leg. Basal insulin supply was reduced up to 50 % on race day. Hormone levels in athletes with type 1 DM and healthy controls were similar. Patients with type 1 DM can successfully sustain extreme endurance challenges. Physiological alterations of the metabolic state complicated by type 1 DM can readily be compensated by adapting intensified insulin therapy and nutritional modifications. Thus 1 DM should not be regarded a contraindication to participating in high endurance sports.

  9. Validated RP-HPLC/DAD Method for the Quantification of Insect Repellent Ethyl 2-Aminobenzoate in Membrane-Moderated Matrix Type Monolithic Polymeric Device.

    Science.gov (United States)

    Islam, Johirul; Zaman, Kamaruz; Chakrabarti, Srijita; Sharma Bora, Nilutpal; Mandal, Santa; Pratim Pathak, Manash; Srinivas Raju, Pakalapati; Chattopadhyay, Pronobesh

    2017-07-01

    A simple, accurate and sensitive reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for the estimation of ethyl 2-aminobenzoate (EAB) in a matrix type monolithic polymeric device and validated as per the International Conference on Harmonization guidelines. The analysis was performed isocratically on a ZORBAX Eclipse plus C18 analytical column (250 × 4.4 mm, 5 μm) and a diode array detector (DAD) using acetonitrile and water (75:25 v/v) as the mobile phase by keeping the flow-rate constant at 1.0 mL/min. Determination of EAB was not interfered in the presence of excipients. Inter- and intra-day relative standard deviations were not higher than 2%. Mean recovery was between 98.7 and 101.3%. Calibration curve was linear in the concentration range of 0.5-10 µg/mL. Limits of detection and quantification were 0.19 and 0.60 µg/mL, respectively. Thus, the present report put forward a novel method for the estimation of EAB, an emerging insect repellent, by using RP-HPLC technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. [The child from families with type 1 diabetes].

    Science.gov (United States)

    Wasikowa, Renata; Suchańska, Dorota; Suchańska, Danuta; Basiak, Aleksander; Noczyńska, Anna; Stasińska, Teresa

    2005-01-01

    Diabetes type 1 is observed in individuals with a genetic predisposition to the disease. Observed is a 3-5 fold risk for congenital defects, therefore diabetes type 1 is one of the highest known teratogenic risk factor. The main factor responsible for the development of congenital defects is hyperglycemia. Observed are congenital defects of the central nervous system, the bones, urinary and digestive tract. Characteristic is macrosomia. Observed are hypocalcemia, hypomagnesemia, polycythemia, hyperbilirubinemia, hypertrophic cardiomyopathy, respiratory disturbances. Children from families with diabetes type 1 are at high risk for the development of the disease in the newborn period, additional diseases. They must be in permanent medical control.

  11. Matrix String Theory

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1997-01-01

    Via compactification on a circle, the matrix model of M-theory proposed by Banks et al suggests a concrete identification between the large N limit of two-dimensional N=8 supersymmetric Yang-Mills theory and type IIA string theory. In this paper we collect evidence that supports this identification. We explicitly identify the perturbative string states and their interactions, and describe the appearance of D-particle and D-membrane states.

  12. SWGELLA DYSENTERIAE TYPE 1 IN KwAZuLU-NATAL

    African Journals Online (AJOL)

    -control. 1995: 15. ure co. LABORATORY SURV~ILLAN.CEOF. SWGELLA DYSENTERIAE TYPE 1 IN. KwAZuLU- ... freeze-dried quality-eontrol specimens were prepared containing ... (National Committee for Clinical Laboratory Standards,.

  13. Type 1 or Type 2 Diabetes and Pregnancy

    Science.gov (United States)

    ... and Pregnancy Articles Type 1 or Type 2 Diabetes and Pregnancy Language: English (US) Español (Spanish) Recommend on Facebook Tweet Share Compartir Problems of Diabetes in Pregnancy Blood sugar that is not well ...

  14. Fertility treatment and childhood type 1 diabetes mellitus

    DEFF Research Database (Denmark)

    Kettner, Laura Ozer; Matthiesen, Niels Bjerregaard; Ramlau-Hansen, Cecilia Høst

    2016-01-01

    OBJECTIVE: To investigate the association between specific types of fertility treatment and childhood type 1 diabetes mellitus. DESIGN: Nationwide birth cohort study. SETTING: Not applicable. PATIENT(S): All pregnancies resulting in a live-born singleton child in Denmark from 1995 to 2003....... INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Childhood type 1 diabetes mellitus identified from redeemed prescriptions for insulin until 2013. RESULT(S): The study included 565,116 singleton pregnancies. A total of 14,985 children were conceived by ovulation induction or intrauterine insemination......, and 8,490 children were conceived by in vitro fertilization or intracytoplasmic sperm injection. During the follow-up period, 2,011 (0.4%) children developed type 1 diabetes mellitus. The primary analyses showed no association between fertility treatment and childhood type 1 diabetes mellitus...

  15. On Generalized Type 1 Logistic Distribution | Ahsanullah | Afrika ...

    African Journals Online (AJOL)

    Some distributional properties of the generalized type 1 logistic distribution are given. Based on these distributional property a characterization of this distribution is presented. Key words: Conditional Expectation; Reversed Hazard Rate; Characterization.

  16. Metabolomic Biomarkers in the Progression to Type 1 Diabetes

    DEFF Research Database (Denmark)

    Overgaard, Anne Julie; Kaur, Simranjeet; Pociot, Flemming

    2016-01-01

    diabetes has been studied using this technique, although in relatively small cohorts and at limited time points. Overall, three observations have been consistently reported; phospholipids at birth are lower in children developing type 1 diabetes early in childhood, methionine levels are lower in children......Metabolomics is the snapshot of all detectable metabolites and lipids in biological materials and has potential in reflecting genetic and environmental factors contributing to the development of complex diseases, such as type 1 diabetes. The progression to seroconversion to development of type 1...... at seroconversion, and triglycerides are increased at seroconversion and associated to microbiome diversity, indicating an association between the metabolome and microbiome in type 1 diabetes progression....

  17. Epidemiology of type 1 (insulin-dependent) diabetes mellitus

    DEFF Research Database (Denmark)

    Green, Anders

    1999-01-01

    Recent estimates suggest that more than 100,000 inhabitants in the Middle East suffer from type 1 diabetes and that about 6000 subjects in the region develop the disease each year. This paper illustrates how epidemiological principles and methods may assist in a rational assessment of the public...... health impact of type 1 diabetes in the Middle East. Making a series of assumptions, it is estimated that the future prevalence of type 1 diabetes in the region will increase slightly, but that the increase may be more pronounced if the disease incidence is increasing and the prognosis improved....... It is recommended that more valid information is established on the basic epidemiological features of type 1 diabetes in the Middle East, as this will provide the basis of more rational planning of the current and future diabetes healthcare in the region....

  18. Long-term mortality and retinopathy in type 1 diabetes

    DEFF Research Database (Denmark)

    Grauslund, Jakob

    2010-01-01

    The incidence of type 1 diabetes is increasing in Denmark as well as the rest of the world. Due to diabetes-related micro- and macrovascular complications, the morbidity and the mortality is higher among type 1 diabetic patients. The aim of this thesis was to examine a population-based cohort...... of 727 type 1 diabetic patients from Fyn County, Denmark, with an onset of diabetes before 1 July 1973 in order to: (1) Evaluate the all-cause mortality rates and the influence of sex, duration of diabetes and calendar year of diagnosis in a 33-year follow-up (Paper I). (2) Examine glycaemic regulation...... of DR was graded higher in the digital photos. Among these, PDR was detected in three eyes using digital photos but remained undetected on all films. This suggests that digital photos with wide fields are the best way to detect DR in long-term type 1 diabetic patients. Overall, it is concluded...

  19. Interleukin-1 antagonism in type 1 diabetes of recent onset

    DEFF Research Database (Denmark)

    Moran, Antoinette; Bundy, Brian; Becker, Dorothy J

    2013-01-01

    Innate immunity contributes to the pathogenesis of autoimmune diseases, such as type 1 diabetes, but until now no randomised, controlled trials of blockade of the key innate immune mediator interleukin-1 have been done. We aimed to assess whether canakinumab, a human monoclonal anti-interleukin-1...... antibody, or anakinra, a human interleukin-1 receptor antagonist, improved β-cell function in recent-onset type 1 diabetes....

  20. Omkostningseffektivitet ved behandling af type 1-diabetes med insulinpumpe

    DEFF Research Database (Denmark)

    Nørgaard, Kirsten; Sohlberg, Anna; Goodall, Gordan

    2010-01-01

    This study's aim was to project the long-term clinical and economic outcomes of continuous subcutaneous insulin infusion (CSII) treatment compared to multiple daily injections (MDI) in type 1 diabetes patients in Denmark.......This study's aim was to project the long-term clinical and economic outcomes of continuous subcutaneous insulin infusion (CSII) treatment compared to multiple daily injections (MDI) in type 1 diabetes patients in Denmark....

  1. Longterm visual prognosis in Usher syndrome types 1 and 2.

    Science.gov (United States)

    Sadeghi, André M; Eriksson, Kristina; Kimberling, William J; Sjöström, Anders; Möller, Claes

    2006-08-01

    To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (type 2 subjects tending to be more impaired, while comparison indicated no significant differences between the groups in any of the other visual field categories. Cataract was found to be generally more common in Usher syndrome type 1 than type 2. Progressive loss of visual acuity and visual field begins to be substantial between the second and third decades of life in both Usher types. The rate of degeneration varies between individuals in both groups. The data are useful for the counselling of affected subjects with Usher syndrome types 1 and 2.

  2. Affinity of hemoglobin for the cytoplasmic fragment of human erythrocyte membrane band 3. Equilibrium measurements at physiological pH using matrix-bound proteins: the effects of ionic strength, deoxygenation and of 2,3-diphosphoglycerate.

    Science.gov (United States)

    Chétrite, G; Cassoly, R

    1985-10-05

    The cytoplasmic fragment of band 3 protein isolated from the human erythrocyte membrane was linked to a CNBr-activated Sepharose matrix in an attempt to measure, in batch experiments, its equilibrium binding constant with oxy- and deoxyhemoglobin at physiological pH and ionic strength values and in the presence or the absence of 2,3-diphosphoglycerate. All the experiments were done at pH 7.2, and equilibrium constants were computed on the basis of one hemoglobin tetramer bound per monomer of fragment. In 10 mM-phosphate buffer, a dissociation constant KD = 2 X 10(-4)M was measured for oxyhemoglobin and was shown to increase to 8 X 10(-4)M in the presence of 50 mM-NaCl. Association could not be demonstrated at higher salt concentrations. Diphosphoglycerate-stripped deoxyhemoglobin was shown to associate more strongly with the cytoplasmic fragment of band 3. In 10 mM-bis-Tris (pH 7.2) and in the presence of 120 mM-NaCl, a dissociation constant KD = 4 X 10(-4)M was measured. Upon addition of increasing amounts of 2,3-diphosphoglycerate, the complex formed between deoxyhemoglobin and the cytoplasmic fragment of band 3 was dissociated. On the reasonable assumption that the hemoglobin binding site present on band 3 fragment was not modified upon linking the protein to the Sepharose matrix, the results indicated that diphosphoglycerate-stripped deoxyhemoglobin or partially liganded hemoglobin tetramers in the T state could bind band 3 inside the intact human red blood cell.

  3. Enhanced aging properties of HKUST-1 in hydrophobic mixed-matrix membranes for ammonia adsorption† †Electronic supplementary information (ESI) available: Experimental procedures. See DOI: 10.1039/c5sc04368a Click here for additional data file.

    Science.gov (United States)

    Denny, Jr., Michael S.; Peterson, Gregory W.; Mahle, John J.

    2016-01-01

    Metal–organic frameworks (MOFs) in their free powder form have exhibited superior capacities for many gases when compared to other materials, due to their tailorable functionality and high surface areas. Specifically, the MOF HKUST-1 binds small Lewis bases, such as ammonia, with its coordinatively unsaturated copper sites. We describe here the use of HKUST-1 in mixed-matrix membranes (MMMs) prepared from polyvinylidene difluoride (PVDF) for the removal of ammonia gas. These MMMs exhibit ammonia capacities similar to their hypothetical capacities based on the weight percent of HKUST-1 in each MMM. HKUST-1 in its powder form is unstable toward humid conditions; however, upon exposure to humid environments for prolonged periods of time, the HKUST-1 MMMs exhibit outstanding structural stability, and maintain their ammonia capacity. Overall, this study has achieved all of the critical and combined elements for real-world applications of MOFs: high MOF loadings, fully accessible MOF surfaces, enhanced MOF stabilization, recyclability, mechanical stability, and processability. This study is a critical step in advancing MOFs to a stable, usable, and enabling technology. PMID:28660045

  4. Insulin gene therapy for type 1 diabetes mellitus.

    Science.gov (United States)

    Handorf, Andrew M; Sollinger, Hans W; Alam, Tausif

    2015-04-01

    Type 1 diabetes mellitus is an autoimmune disease resulting from the destruction of pancreatic β cells. Current treatments for patients with type 1 diabetes mellitus include daily insulin injections or whole pancreas transplant, each of which are associated with profound drawbacks. Insulin gene therapy, which has shown great efficacy in correcting hyperglycemia in animal models, holds great promise as an alternative strategy to treat type 1 diabetes mellitus in humans. Insulin gene therapy refers to the targeted expression of insulin in non-β cells, with hepatocytes emerging as the primary therapeutic target. In this review, we present an overview of the current state of insulin gene therapy to treat type 1 diabetes mellitus, including the need for an alternative therapy, important features dictating the success of the therapy, and current obstacles preventing the translation of this treatment option to a clinical setting. In so doing, we hope to shed light on insulin gene therapy as a viable option to treat type 1 diabetes mellitus.

  5. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  6. Glutaric aciduria type 1--importance of early diagnosis and treatment.

    Science.gov (United States)

    Afroze, Bushra; Yunus, Zabedah Mohammad

    2014-05-01

    Glutaric aciduria type 1 is a rare inherited organic academia. Untreated patients characteristically develop dystonia secondary to striatal injury during early childhood, which results in high morbidity and mortality. In patients diagnosed during neonatal period, striatal injury can be prevented by metabolic treatment including low lysine diet, carnitine supplementation and aggressive emergency treatment during acute episode of inter current illnesses. However, after the onset of neurological damage initiation of treatment is generally not effective. Therefore; glutaric aciduria type 1 is included in newborn screening panel for inherited metabolic diseases in many countries. We describe two children in a family with glutaric aciduria type 1 and their different long term outcomes. The first child was diagnosed late leading to severe neurological damage. The second child was diagnosed in the neonatal period as a result of selective high-risk screening and was treated appropriately giving a normal growth.

  7. Adolescents developing life skills for managing type 1 diabetes

    DEFF Research Database (Denmark)

    Husted, Gitte R; Esbensen, Bente Appel; Hommel, Eva

    2014-01-01

    AIM: To explore and illustrate how the Guided Self-Determination-Youth method influences the development of life skills in adolescents with type 1 diabetes supported by their parents and healthcare providers. BACKGROUND: Evidence-based methods that accomplish constructive cooperation between...... adolescents with poorly controlled type 1 diabetes, their parents and healthcare providers are needed. We adjusted an adult life skills intervention comprising reflection sheets and advanced communication for use by adolescent-parent-professional triads in outpatient visits. DESIGN: A qualitative realistic...... with type 1 diabetes for ≥1 year and having poor glycaemic control participated together with 17 parents and eight healthcare providers. Data were collected from December 2009-March 2012 and consisted of digitally recorded outpatient Guide Self-Determination-Youth visits collected during the intervention...

  8. ARX MPC for people with type 1 diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Finan, Daniel Aaron; Jørgensen, John Bagterp

    Type 1 diabetes is a chronic disease characterized by a lack of production of pancreatic insulin, consequently leading to high blood glucose concentrations (hyperglycemia). Hyperglycemia has negative health effects in the long term such as eye, nerve, and kidney disease. Exogenous insulin must......, or even death. Currently, insulin administration is performed by the subject with type 1 diabetes based on infrequent glucose measurements (in the form of finger-sticks), often resulting in an unsatisfactory blood glucose control. An artificial pancreas is a medical device that injects exogenous insulin...... and insulin injection information to compute the optimal insulin administration for the current conditions. We use model predictive control (MPC) to compute the optimal insulin administration for 20 virtual type 1 diabetes subjects. The system (i.e., subject) has one manipulated input (insulin infusion rate...

  9. The pregnancy journey for women with type 1 diabetes

    DEFF Research Database (Denmark)

    Edwards, Helen; Speight, Jane; Bridgman, Heather

    2016-01-01

    The purpose of this study is to describe and develop a model of the pregnancy journey for women with type 1 diabetes. We undertook a thematic analysis of written interactions (n = 200; n = 2060 text excerpts) with an online counselling support service from 93 women with type 1 diabetes. Seven...... reassurance during Pregnancy; however, some women still worried, with peer support offering the most reassurance. In conclusion, women with type 1 diabetes potentially experience seven distinct phases of the pregnancy journey, with eight themes varying in significance across phases. Contemplation begins well...... possible discrete phases in the pregnancy journey were revealed: Contemplation, Pregnancy planning, Conception, Pregnancy, Delivery/birth, and Motherhood or Pregnancy loss. Eight common themes were identified, varying in importance across phases. Diabetes-specific distress was most evident during...

  10. Severe hypoglycaemia in 1076 adult patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, Ulrik; Pramming, Stig; Heller, Simon R

    2004-01-01

    BACKGROUND: Differences between studies in rates of severe hypoglycaemia in type 1 diabetic cohorts are common and poorly understood. The purpose of this study was to assess the frequency of severe hypoglycaemia in unselected patients treated in different secondary care centres and to evaluate...... the influence of risk markers, clinical setting and selection. METHODS: Cross-sectional Danish-British multicentre survey of 1076 consecutive adult patients with clinical type 1 diabetes who completed a detailed questionnaire on hypoglycaemia and related issues. Key variable was the self-reported rate of severe......, the rate of severe hypoglycaemia was 0.35 episodes/patient-year and only retinopathy was a significant risk marker together with state of awareness. CONCLUSION: Severe hypoglycaemia remains a significant clinical problem in type 1 diabetes. The rate of severe hypoglycaemia and the influence of risk markers...

  11. Hypoglycaemia during pregnancy in women with Type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Pedersen-Bjergaard, U; Thorsteinsson, B

    2012-01-01

    Diabet. Med. 29, 558-566 (2012) ABSTRACT: Aims To explore incidence, risk factors, possible pathophysiological factors and clinical management of hypoglycaemia during pregnancy in women with Type 1 diabetes. Methods Literature review. Results In women with Type 1 diabetes, severe hypoglycaemia......% of the pregnant women account for 60% of all recorded events. Risk factors for severe hypoglycaemia during pregnancy include a history with severe hypoglycaemia in the year preceding pregnancy, impaired hypoglycaemia awareness, long duration of diabetes, low HbA(1c) in early pregnancy, fluctuating plasma glucose...... should have high priority among clinicians with the persistent aim of improving pregnancy outcome among women with Type 1 diabetes. Pre-conception counselling, carbohydrate counting, use of insulin analogues, continuous subcutaneous insulin infusion (insulin pump) therapy and real-time continuous glucose...

  12. New technologies in the treatment of type 1 diabetes

    DEFF Research Database (Denmark)

    Schmidt, Signe

    2013-01-01

    Type 1 diabetes is a chronic condition characterized by insufficient production of insulin, a hormone needed for proper control of blood glucose levels. People with type 1 diabetes must monitor their blood glucose throughout the day using a glucose meter or a continuous glucose monitor, calculate...... how much insulin is needed to maintain normal blood glucose levels, and administer the insulin dose by pen injection or insulin pump infusion into the subcutaneous tissue. In recent years, several new technologies for the treatment of type 1 diabetes have been developed. This PhD thesis covers two...... studies of the effects of commercially available technologies--sensor-augmented pump therapy and automated insulin bolus calculators--when used in clinical practice. Both studies demonstrated that these technologies have the potential to improve diabetes care. In addition, two in-clinic studies related...

  13. Type 1 Tyrosinemia with Hypophosphatemic Rickets; a Case Report

    Directory of Open Access Journals (Sweden)

    Peyman Eshraghi

    2014-09-01

    Full Text Available Background: Tyrosinemia type 1 is an autosomal recessive metabolic disorder, which typically affects liver and kidneys. It is caused by a defect in fumarylacetoacetate hydrolase or fumarylacetoacetase (FAH enzyme, the final enzyme in the tyrosine degradation pathway. The disease typically manifests as early onset type in early infancy with acute hepatic crisis with hepatomegaly and bleeding tendency. In 1992, a new drug orfadin (NTBC, Nitisinone which is a potent inhibitor of 4 hydroxy phenyl pyrovate dioxygenase has revolutionized the treatment of tyrosinemia type 1 and is now the mainstry of therapy. Case presentation: Our case was a girl in midchidhood period with profound rickets and slowly progressing liver disease who presented with difficulty walking and weakness of muscles. She had an elevated serum tyrosine and urinary succinylacetone, which confirmed the diagnosis of tyrosinemia type 1 and after treatment with NTBC significant remission, was achieved.

  14. Hand functions in type 1 and type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Akpinar Pinar

    2017-01-01

    Full Text Available Introduction/Objective. Hand functions have an enormous impact on activities of daily living in patients with diabetes mellitus (DM, such as self-care, administering insulin injections, and preparing and eating meals. The aim of the study was to evaluate hand functions and grip strength in patients with type 1 and type 2 DM. Methods. This was an observational case-control study investigating the hand functions and grip strength in patients with type 1 and type 2 DM. The study comprised 41 patients with type 1 DM aged 25–50 years sex- and age-matched, 40 non-diabetic controls, and 91 patients with type 2 DM aged 40–65 years sex- and age-matched 60 non-diabetic controls. Patients with documented history of diabetic sensorimotor neuropathy and adhesive capsulitis were excluded. The Duruoz Hand Index was used to assess the functional hand disability. Grip strength was tested with a calibrated Jamar dynamometer. Results. The Duruoz Hand Index scores in patients with type 2 DM were significantly higher than in persons in the control group (p 0.05. Grip strength values of patients with type 1 DM were significantly lower compared to those in the control group (p < 0.05, whereas there was no significant difference between patients with type 2 DM and their control group. There was a negatively significant correlation between grip strength and the Duruoz Hand Index scores in patients with both type 1 and type 2 DM (p < 0.05. Conclusion. Patients with type 1 DM and type 2 DM have different degrees of hand disability as compared to healthy control groups.

  15. Confirmation of novel type 1 diabetes risk loci in families

    DEFF Research Database (Denmark)

    Cooper, J D; Howson, J M M; Smyth, D

    2012-01-01

    Over 50 regions of the genome have been associated with type 1 diabetes risk, mainly using large case/control collections. In a recent genome-wide association (GWA) study, 18 novel susceptibility loci were identified and replicated, including replication evidence from 2,319 families. Here, we......, the Type 1 Diabetes Genetics Consortium (T1DGC), aimed to exclude the possibility that any of the 18 loci were false-positives due to population stratification by significantly increasing the statistical power of our family study....

  16. US Army Soldiers With Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Choi, Y Sammy; Cucura, Jon

    2018-04-01

    US Army soldiers diagnosed with type 1 diabetes were previously considered unfit for duty. For highly motivated soldiers, current advanced technologies allow the possibility of not only retention on active duty, but military deployment. We present our experience at Fort Bragg, North Carolina, taking care of soldiers newly diagnosed with type 1 diabetes mellitus. Through intensive diabetes education, extensive military and physical training, optimization of diabetes technology, and remote real-time monitoring, soldiers are able to continue to serve their country in the most specialized roles.

  17. A Quasi-Type-1 Phase-Locked Loop Structure

    DEFF Research Database (Denmark)

    Golestan, Saeed; Fernandez, Francisco Daniel Freijedo; Vidal, Ana

    2014-01-01

    The grid voltage phase and frequency are crucial information in control of most grid connected power electronic based equipment. Most often, a phase-locked loop (PLL) is employed for this purpose. A PLL is a closed-loop feedback control system that the phase of its output signal is related...... to the phase of its input signal. Arguably, the simplest PLL is a type-1 PLL. The type-1 PLLs are characterized by having only one integrator in their control loop and therefore having a high stability margin. However, they suffer from a serious drawback: they cannot achieve zero average steady-state phase...

  18. Continuous subcutaneous insulin infusion preserves axonal function in type 1 diabetes mellitus.

    Science.gov (United States)

    Kwai, Natalie; Arnold, Ria; Poynten, Ann M; Lin, Cindy S-Y; Kiernan, Matthew C; Krishnan, Arun V

    2015-02-01

    Diabetic peripheral neuropathy is a common and debilitating complication of diabetes mellitus. Although strict glycaemic control may reduce the risk of developing diabetic peripheral neuropathy, the neurological benefits of different insulin regimens remain relatively unknown. In the present study, 55 consecutive patients with type 1 diabetes mellitus underwent clinical neurological assessment. Subsequently, 41 non-neuropathic patients, 24 of whom were receiving multiple daily insulin injections (MDII) and 17 receiving continuous subcutaneous insulin infusion (CSII), underwent nerve excitability testing, a technique that assesses axonal ion channel function and membrane potential in human nerves. Treatment groups were matched for glycaemic control, body mass index, disease duration and gender. Neurophysiological parameters were compared between treatment groups and those taken from age and sex-matched normal controls. Prominent differences in axonal function were noted between MDII-treated and CSII-treated patients. Specifically, MDII patients manifested prominent abnormalities when compared with normal controls in threshold electrotonus (TE) parameters including depolarizing TE(10-20ms), undershoot and hyperpolarizing TE (90-100 ms) (P type 1 diabetes is maintained within normal limits in patients treated with continuous subcutaneous insulin infusion and not with multiple daily insulin injections. This raises the possibility that CSII therapy may have neuroprotective potential in patients with type 1 diabetes. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Leprosy type 1 reactions and erythema nodosum leprosum

    OpenAIRE

    Kahawita,Indira P.; Walker,Stephen L.; Lockwood,Diana N.J.

    2008-01-01

    Leprosy reactions are a major cause of nerve damage and morbidity in a significant proportion of leprosy patients. Reactions are immunologically mediated and can occur even after successful completion of multi-drug therapy. This review focuses on the epidemiology, pathology and treatment of leprosy type 1 reactions, erythema nodosum leprosum and silent neuropathy.

  20. Isolation of Ancestral Sylvatic Dengue Virus Type 1, Malaysia

    Science.gov (United States)

    Teoh, Boon-Teong; Sam, Sing-Sin; Abd-Jamil, Juraina

    2010-01-01

    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle. PMID:21029545

  1. Improving School Experiences for Adolescents with Type 1 Diabetes

    Science.gov (United States)

    Kise, Saori S.; Hopkins, Amanda; Burke, Sandra

    2017-01-01

    Background: Diabetes mellitus (diabetes) is one of the most common metabolic diseases in children worldwide and the incidence of type 1 diabetes (T1D) is growing. T1D is complicated to manage and adolescents with diabetes face unique, age-specific challenges. The purpose of this article is to discuss ways in which schools can create a positive…

  2. Peptide and protein biomarkers for type 1 diabetes mellitus

    Science.gov (United States)

    Zhang, Qibin; Metz, Thomas O.

    2016-08-30

    A method for identifying persons with increased risk of developing type 1 diabetes mellitus, or having type I diabetes mellitus, utilizing selected biomarkers described herein either alone or in combination. The present disclosure allows for broad based, reliable, screening of large population bases. Also provided are arrays and kits that can be used to perform such methods.

  3. Caring for Students with Type 1 Diabetes: School Nurses' Experiences

    Science.gov (United States)

    Wang, Yueh-Ling; Volker, Deborah L.

    2013-01-01

    This qualitative study used a Husserlian phenomenological approach to obtain an understanding of the essences of five experienced Taiwanese school nurses' lived experience of caring for students with type 1 diabetes mellitus (T1DM). Audio-recorded, semi-structured, in-depth interviews were conducted. Data analysis entailed a modified method from…

  4. Determinants of daily insulin use in Type 1 diabetes

    NARCIS (Netherlands)

    Muis, Marian J.; Bots, Michiel L.; Bilo, Henk J. G.; Hoogma, Roel P. L. M.; Hoekstra, Joost B. L.; Grobbee, Diederick E.; Stolk, Ronald P.

    2006-01-01

    OBJECTIVE: Insulin need for a given degree of glucose control varies markedly among individuals. We examined which factors determine daily insulin use in patients with Type 1 diabetes. METHODS: A cross-sectional study was performed in 416 patients. Clinical parameters, medication use, physical

  5. Antigenic variation and resistance to neutralization in poliovirus type 1.

    NARCIS (Netherlands)

    D.C. Diamond; B.A. Jameson; J. Bonin; M. Kohara; S. Abe; H. Itoh; T. Komatsu; M. Arita; S. Kuge; A. Nomoto; A.D.M.E. Osterhaus (Albert); R. Crainic; E. Wimmer

    1985-01-01

    textabstractMutations have been identified in variants of poliovirus, type 1 (Mahoney) on the basis of their resistance to neutralization by individual monoclonal antibodies. The phenotypes of these variants were defined in terms of antibody binding; the pattern of epitopes expressed or able to be

  6. Increased basal glucose production in type 1 Gaucher's disease

    NARCIS (Netherlands)

    Corssmit, E. P.; Hollak, C. E.; Endert, E.; van Oers, M. H.; Sauerwein, H. P.; Romijn, J. A.

    1995-01-01

    To evaluate the metabolic effects of Gaucher's disease, glucose metabolism and parameters of fat metabolism were studied by indirect calorimetry and primed continuous infusion of [3-3H]glucose in seven clinically stable untreated patients with type 1 Gaucher's disease and in seven healthy matched

  7. Motor problems in children with neurofibromatosis type 1

    NARCIS (Netherlands)

    A.B. Rietman (André); R. Oostenbrink (Rianne); Bongers, S. (Sanne); Gaukema, E. (Eddy); Van Abeelen, S. (Sandra); J.G.M. Hendriksen; C.W.N. Looman (Caspar); P.F.A. de Nijs (Pieter); M.C.Y. de Wit (Marie Claire)

    2017-01-01

    textabstractBackground: Children with the neurogenetic disorder neurofibromatosis type 1 (NF1) often have problems with learning and behaviour. In both parent reports and neuropsychological assessment, motor problems are reported in approximately one third to one half of the children with NF1.

  8. [Adolescents with diabetes type 1 in adolescent psychiatry and psychotherapy].

    Science.gov (United States)

    Walter, Joachim

    2013-01-01

    Psychiatric comorbidity, family and biographical risk factors, and individual motivational aspects influence the therapeutic adherence and treatment motivation in Diabetes Type 1. The article provides basis diabetological knowledge for adolescent psychotherapists and describes practical out- and inpatient experiences and deliberations with especially problematic comorbid patients. In psychiatrically comorbid patients family conflicts and individual psychopathology is often reflected and manifested in selfharming diabetes management.

  9. Type 1 diabetes mellitus and atopic diseases in children.

    African Journals Online (AJOL)

    Ehab

    Nancy S. Elbarbary. Assistant Professor of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt. Background. Diabetes mellitus type 1 (T1DM) is a complex disease resulting from the interplay of genetic, epigenetic, and environmental factors.1 Worldwide,. T1DM epidemic represents an increasing global.

  10. The vaccines for Bovine Herpesvirus Type 1: A review | Zhao ...

    African Journals Online (AJOL)

    Bovine herpesvirus type 1 (BoHV-1) is the pathogen of Infectious Bovine Rhinothracheitis (IBR) disease, causing great economic losses in the livestock industry. Vaccine is a powerful means to control the virus. Here, the review described the currently available knowledge regarding to the advance in the field of BoHV-1 ...

  11. Type 1,1-operators defined by vanishing frequency modulation

    DEFF Research Database (Denmark)

    Johnsen, Jon

    2009-01-01

    This paper presents a general definition of pseudo-differential operators of type 1,1; the definition is shown to be the largest one that is both compatible with negliible operators and stable under vanishing frequency modulation. Elaborating counter-examples of Ching, Hörmander and Parenti...

  12. Case report: type 1 diabetes in monozygotic quadruplets

    Czech Academy of Sciences Publication Activity Database

    Štechová, K.; Halbhuber, Z.; Hubáčková, M.; Kayserová, J.; Petruželková, L.; Včeláková, J.; Koloušková, S.; Ulmannová, T.; Faresjo, M.; Neuwirth, Aleš; Spíšek, R.; Šedivá, A.; Filipp, Dominik; Sumnik, Z.

    2012-01-01

    Roč. 20, č. 4 (2012), s. 457-462 ISSN 1018-4813 R&D Projects: GA MŠk 2B08066 Institutional research plan: CEZ:AV0Z50520514 Keywords : autoimmunity * type 1 diabetes * beta cell s Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.319, year: 2012

  13. Viral infections as potential triggers of type 1 diabetes

    NARCIS (Netherlands)

    van der Werf, Nienke; Kroese, Frans G. M.; Rozing, Jan; Hillebrands, Jan-Luuk

    During the last decades, the incidence of type 1 diabetes (T1D) has increased significantly, reaching percentages of 3% annually worldwide. This increase suggests that besides genetical factors environmental perturbations (including viral infections) are also involved in the pathogenesis of T1D. T1D

  14. Neuroendocrine Tumour in a Patient with Neurofibromatosis Type 1 ...

    African Journals Online (AJOL)

    We report the case of an HIV-positive female patient with neurofibromatosis type 1 who was treated for recurrent peptic ulcer disease and later developed diabetes mellitus and chronic diarrhoea. A metastasising somatostatinoma was histologically proven and evidence of a concomitant gastrin-producing neuroendocrine ...

  15. Reflex sympathetic dystrophy/complex regional pain syndrome, type 1

    African Journals Online (AJOL)

    Enrique

    with MRI every 3 months and the bone marrow oedema disappeared after 6 months. Introduction ... SA JOURNAL OF RADIOLOGY • August 2004. Reflex sympathetic dystrophy/complex regional pain syndrome, type 1 ... may be either trauma of external origin or iatrogenic, post surgery. In some patients particularly children ...

  16. Human immunodeficiency virus type-1 (HIV-1) genetic diversity and ...

    African Journals Online (AJOL)

    The presence of human immunodeficiency virus (HIV) type-1 diversity has an impact on vaccine efficacy and drug resistance. It is important to know the circulating genetic variants and associated drug-resistance mutations in the context of scale up of antiretroviral therapy (ART) in Nigeria. The objective of this study was to ...

  17. Immunological Adaptations to Pregnancy in Women with Type 1 Diabetes

    NARCIS (Netherlands)

    Groen, Bart; van der Wijk, Anne-Eva; van den Berg, Paul P.; Lefrandt, Joop D.; van den Berg, Gerrit; Sollie, Krystina M.; de Vos, Paul; Links, Thera P.; Faas, Marijke M.

    2015-01-01

    Despite adequate glycemic control, pregnancy outcome of women with type 1 diabetes (T1D) is still unfavorable as compared to healthy women. In a rat-model of T1D under normoglycemic conditions, adverse pregnancy outcome was also observed, which was associated with aberrant immunological adaptations

  18. Non HLA genetic markers association with type-1 diabetes mellitus ...

    African Journals Online (AJOL)

    The currently available data identified IDDM1 and IDDM2 as 2 susceptibility loci for type 1 diabetes (T1D). The major histocompatibility complex (MHC)/HLA region referred to as IDDM1 contains several 100 genes known to have a great influence on T1D risk. Within IDDM2, a minisatellite variable number of tandem repeats ...

  19. Type 1 diabetes and obesity in children : Focus on inflammation

    NARCIS (Netherlands)

    Verrijn Stuart, A.A.

    2013-01-01

    Type 1 diabetes (T1D) is an inflammatory disorder as is obesity. This thesis addresses inflammatory features in both conditions, with focus on inflammatory mediators and the role of adipose tissue (AT). The first part, specific aspects of immune tolerance in T1D,focuses on immune (dys) regulation

  20. Personality profiles of children and adolescents with neurofibromatosis type 1

    NARCIS (Netherlands)

    Prinzie, P.; Descheemaeker, M.J.; Vogels, A.; Cleymans, T.; Haselager, G.J.T.; Curfs, L.M.G.; Hellinckx, W.; Onghena, P.; Legius, E.; Lieshout, C.F.M. van; Fryns, J.P.

    2003-01-01

    The personality profile of 44 youngsters (24 males, 20 females; mean age 11 years, 3 months) with neurofibromatosis type 1 (NF1) was compared with a group of 220 non-NF1 control youngsters (matched on age and gender). Personality characteristics of each youngster were rated by both parents, using

  1. Sensor Augmented Pump Therapy Use in Type 1 Diabetes Mellitus

    LENUS (Irish Health Repository)

    Carolan, E

    2016-11-01

    Tight metabolic control in Type 1 Diabetes Mellitus (T1DM) reduces incidence and delays progression of micro-vascular complications. Severe hypoglycaemia remains a significant barrier to achieving optimal diabetes control. Continuous subcutaneous insulin infusion (CSII) systems refine insulin delivery with programmable basal rates and mealtime bolusing

  2. Exercise management in type 1 diabetes: a consensus statement.

    Science.gov (United States)

    Riddell, Michael C; Gallen, Ian W; Smart, Carmel E; Taplin, Craig E; Adolfsson, Peter; Lumb, Alistair N; Kowalski, Aaron; Rabasa-Lhoret, Remi; McCrimmon, Rory J; Hume, Carin; Annan, Francesca; Fournier, Paul A; Graham, Claudia; Bode, Bruce; Galassetti, Pietro; Jones, Timothy W; Millán, Iñigo San; Heise, Tim; Peters, Anne L; Petz, Andreas; Laffel, Lori M

    2017-05-01

    Type 1 diabetes is a challenging condition to manage for various physiological and behavioural reasons. Regular exercise is important, but management of different forms of physical activity is particularly difficult for both the individual with type 1 diabetes and the health-care provider. People with type 1 diabetes tend to be at least as inactive as the general population, with a large percentage of individuals not maintaining a healthy body mass nor achieving the minimum amount of moderate to vigorous aerobic activity per week. Regular exercise can improve health and wellbeing, and can help individuals to achieve their target lipid profile, body composition, and fitness and glycaemic goals. However, several additional barriers to exercise can exist for a person with diabetes, including fear of hypoglycaemia, loss of glycaemic control, and inadequate knowledge around exercise management. This Review provides an up-to-date consensus on exercise management for individuals with type 1 diabetes who exercise regularly, including glucose targets for safe and effective exercise, and nutritional and insulin dose adjustments to protect against exercise-related glucose excursions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Charcot-Marie-Tooth disease type 1A

    DEFF Research Database (Denmark)

    Hertz, Jens Michael; Børglum, A D; Brandt, C A

    1994-01-01

    Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant peripheral neuropathy associated with a DNA duplication on chromosome 17p11.2-p12 in the majority of cases. Most of the sporadic cases are due to a de novo duplication. We have screened for this duplication in 11 Danish patients...

  4. Osteomyelitis in leukocyte adhesion deficiency type 1 syndrome

    DEFF Research Database (Denmark)

    Jabbari Azad, Farahzad; Ardalan, Maryam; H.Rafati, Ali

    2010-01-01

    Leukocyte adhesion deficiency type 1 (LAD-1) is a rare, inherited immunodeficiency that affects one per million people yearly and usually presents with recurrent, indolent bacterial infections of the skin, mouth, and respiratory tract and impaired pus formation and wound healing. A 13-year-old girl...

  5. [Complex regional pain syndrome type 1: negating the myth

    NARCIS (Netherlands)

    Frolke, J.P.M.; Dongen, R.T.M. van; Meent, H. van de

    2015-01-01

    Complex regional pain syndrome type 1 (CRPS-1) was identified in the Netherlands more than 30 years ago, but since then the arguments supporting this diagnosis have become weaker. Incidence has decreased, it is often not possible to make a definite diagnosis, the pathophysiology remains unclear and

  6. Chronic comorbidities in children and adolescents with type 1 diabetes

    NARCIS (Netherlands)

    Fazelifarsani, Soulmaz; Souverein, Patrick C.; Van Der Vorst, Marja M.J.; Knibbe, Catherijne A.J.; De Boer, Anthonius; Mantel-Teeuwisse, Aukje K.

    2014-01-01

    Background: Limited quantitative data exist on the burden of chronic comorbidities in children and adolescents with type 1 diabetes (T1D). Such knowledge is necessary for the development of guidelines and prevention programs. Objectives: To determine the incidence of chronic comorbidities in

  7. Overnight glucose control in people with type 1 diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Duun-Henriksen, Anne Katrine; Schmidt, Signe

    2018-01-01

    This paper presents an individualized model predictive control (MPC) algorithm for overnight blood glucose stabilization in people with type 1 diabetes (T1D). The MPC formulation uses an asymmetric objective function that penalizes low glucose levels more heavily. We compute the model parameters...

  8. Continuous glucose monitoring systems for type 1 diabetes mellitus

    NARCIS (Netherlands)

    Langendam, Miranda; Luijf, Yoeri M.; Hooft, Lotty; DeVries, J. Hans; Mudde, Aart H.; Scholten, Rob J. P. M.

    2012-01-01

    Background Self-monitoring of blood glucose is essential to optimise glycaemic control in type 1 diabetes mellitus. Continuous glucose monitoring (CGM) systems measure interstitial fluid glucose levels to provide semi-continuous information about glucose levels, which identifies fluctuations that

  9. Insulin analogues and severe hypoglycaemia in type 1 diabetes

    DEFF Research Database (Denmark)

    Kristensen, P L; Hansen, L S; Jespersen, M J

    2012-01-01

    The effect of insulin analogues on glycaemic control is well-documented, whereas the effect on avoidance of severe hypoglycaemia remains tentative. We studied the frequency of severe hypoglycaemia in unselected patients with type 1 diabetes treated with insulin analogues, human insulin, or mixed...

  10. Imaging Finding of Multiple Endocrine Neoplasia Type 1: Case Report

    International Nuclear Information System (INIS)

    Yum, Tae Jun; Cho, Hee Woo

    2012-01-01

    Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited syndrome with characteristic clinical and radiological manifestations. Many reports on MEN1 have been published; however, no cases of radiologically diagnosed MEN1 have been reported. Therefore, we report on a radiologically diagnosed case of MEN1 with clinical symptoms of gastroduodenal ulcer.

  11. Characteristics of children presenting with newly diagnosed type 1 ...

    African Journals Online (AJOL)

    The clinical presentation of type 1 diabetes in children can be acute or insidious, and symptoms may be subtle ... weakness, together with simple bedside tests such as urine dipsticks ... a recent worldwide focus on programmes to reduce the incidence .... by parents, asking the correct questions by medical personnel, and.

  12. Nuclear Receptors and Multiple Endocrine Neoplasia type 1 (MEN1)

    NARCIS (Netherlands)

    Dreijerink, K.M.A.

    2009-01-01

    Multiple Endocrine Neoplasia type 1 (MEN1) is an inherited syndrome that is characterized by the occurrence of tumours of the parathyroid glands, gastroenteropancreatic tumours, pitui-tary gland adenomas, as well as adrenal adenomas and neuro-endocrine tumours, often at a young age. MEN1 tumours can

  13. Speech Disorders in Neurofibromatosis Type 1: A Sample Survey

    Science.gov (United States)

    Cosyns, Marjan; Vandeweghe, Lies; Mortier, Geert; Janssens, Sandra; Van Borsel, John

    2010-01-01

    Background: Neurofibromatosis type 1 (NF1) is an autosomal-dominant neurocutaneous disorder with an estimated prevalence of two to three cases per 10 000 population. While the physical characteristics have been well documented, speech disorders have not been fully characterized in NF1 patients. Aims: This study serves as a pilot to identify key…

  14. Reproduction and fertility in human immunodeficiency virus type-1 infection

    NARCIS (Netherlands)

    van Leeuwen, E.; Prins, J. M.; Jurriaans, S.; Boer, K.; Reiss, P.; Repping, S.; van der Veen, F.

    2007-01-01

    Human immunodeficiency virus type-1 (HIV-1) affects mostly men and women in their reproductive years. For those who have access to highly active antiretroviral therapy (HAART), the course of HIV-1 infection has shifted from a lethal to a chronic disease. As a result of this, many patients with HIV-1

  15. Genetics Home Reference: acute necrotizing encephalopathy type 1

    Science.gov (United States)

    ... encephalopathy type 1 typically appears in infancy or early childhood, although some people do not develop the condition ... status and number of prior infections, may also influence risk. Related ... it mean if a disorder seems to run in my family? What are the different ways in which a ...

  16. NMR Structure of the Myristylated Feline Immunodeficiency Virus Matrix Protein

    Directory of Open Access Journals (Sweden)

    Lola A. Brown

    2015-04-01

    Full Text Available Membrane targeting by the Gag proteins of the human immunodeficiency viruses (HIV types-1 and -2 is mediated by Gag’s N-terminally myristylated matrix (MA domain and is dependent on cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5P2]. To determine if other lentiviruses employ a similar membrane targeting mechanism, we initiated studies of the feline immunodeficiency virus (FIV, a widespread feline pathogen with potential utility for development of human therapeutics. Bacterial co-translational myristylation was facilitated by mutation of two amino acids near the amino-terminus of the protein (Q5A/G6S; myrMAQ5A/G6S. These substitutions did not affect virus assembly or release from transfected cells. NMR studies revealed that the myristyl group is buried within a hydrophobic pocket in a manner that is structurally similar to that observed for the myristylated HIV-1 protein. Comparisons with a recent crystal structure of the unmyristylated FIV protein [myr(-MA] indicate that only small changes in helix orientation are required to accommodate the sequestered myr group. Depletion of PI(4,5P2 from the plasma membrane of FIV-infected CRFK cells inhibited production of FIV particles, indicating that, like HIV, FIV hijacks the PI(4,5P2 cellular signaling system to direct intracellular Gag trafficking during virus assembly.

  17. NMR structure of the myristylated feline immunodeficiency virus matrix protein.

    Science.gov (United States)

    Brown, Lola A; Cox, Cassiah; Baptiste, Janae; Summers, Holly; Button, Ryan; Bahlow, Kennedy; Spurrier, Vaughn; Kyser, Jenna; Luttge, Benjamin G; Kuo, Lillian; Freed, Eric O; Summers, Michael F

    2015-04-30

    Membrane targeting by the Gag proteins of the human immunodeficiency viruses (HIV types-1 and -2) is mediated by Gag's N-terminally myristylated matrix (MA) domain and is dependent on cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. To determine if other lentiviruses employ a similar membrane targeting mechanism, we initiated studies of the feline immunodeficiency virus (FIV), a widespread feline pathogen with potential utility for development of human therapeutics. Bacterial co-translational myristylation was facilitated by mutation of two amino acids near the amino-terminus of the protein (Q5A/G6S; myrMAQ5A/G6S). These substitutions did not affect virus assembly or release from transfected cells. NMR studies revealed that the myristyl group is buried within a hydrophobic pocket in a manner that is structurally similar to that observed for the myristylated HIV-1 protein. Comparisons with a recent crystal structure of the unmyristylated FIV protein [myr(-)MA] indicate that only small changes in helix orientation are required to accommodate the sequestered myr group. Depletion of PI(4,5)P2 from the plasma membrane of FIV-infected CRFK cells inhibited production of FIV particles, indicating that, like HIV, FIV hijacks the PI(4,5)P2 cellular signaling system to direct intracellular Gag trafficking during virus assembly.

  18. Focal adhesions and cell-matrix interactions

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms...

  19. Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis

    OpenAIRE

    Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F

    1998-01-01

    Background—Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). 
Aims—Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. 
Patients—Twenty one patients with type 2 AIH were studied. 
Methods—A...

  20. Risk factors for necrobiosis lipoidica in Type 1 diabetes mellitus.

    Science.gov (United States)

    Hammer, E; Lilienthal, E; Hofer, S E; Schulz, S; Bollow, E; Holl, R W

    2017-01-01

    To compare the clinical and metabolic characteristics of patients with Type 1 diabetes and necrobiosis lipoidica with those of patients with Type 1 diabetes who do not have necrobiosis lipoidica. A multicentre analysis was performed. Clinical and laboratory data were obtained from 64 133 patients (aged 0-25 years) with Type 1 diabetes with and without necrobiosis lipoidica who were registered in the German/Austrian Diabetes Prospective Documentation Initiative registry. Data were analysed using multivariable regression modelling. Age, diabetes duration, treatment year and sex were considered as confounding factors. Results adjusted for demographic variables are presented. In patients with necrobiosis lipoidica, metabolic control was worse (HbA 1c 72 vs. 67 mmol/mol, 8.7% vs. 8.3%; P = 0.0065) and the duration of diabetes was longer [6.24 (3.28-9.97) vs. 5.11 (2.08-8.83) years; P = 0.014; not adjusted]. Patients with necrobiosis lipoidica required higher insulin doses than those without (1.02 vs. 0.92 U/kg/day; P 1). There was no significant difference in the frequency of microvascular complications (microalbuminuria and retinopathy) between the groups. Furthermore, 24.8% and 17.5% of patients with Type 1 diabetes with and without necrobiosis lipoidica, respectively, had elevated thyroid antibodies (P = 0.051). Necrobiosis lipoidica was correlated with coeliac disease in patients with Type 1 diabetes (3.4% vs. 1.0%; P = 0.0035). Our data indicate a strong correlation between hyperglycaemia and the development of necrobiosis lipoidica. We postulate that the underlying pathogenic processes differ from those leading to microalbuminuria and retinopathy, and additional immunological mechanisms may play a role. © 2016 Diabetes UK.

  1. Cardiorenal Syndrome Type 1: Definition, Etiopathogenesis, Diagnostics and Treatment

    Directory of Open Access Journals (Sweden)

    Nikolic Tomislav

    2018-03-01

    Full Text Available Cardiorenal Syndrome Type 1 (CRS-1 is defined as an acute worsening of heart function leading to acute kidney injury and/or dysfunction. It is an important cause of hospitalization which affects the diagnosis as well as the prognosis and treatment of patients. The purpose of this paper is to analyze causes that lead to the development of cardiorenal syndrome type 1 and its clinical consequences, as well as to emphasize the clinical importance of its early detection. The clinical studies and professional papers dealing with etiopathogenesis, diagnosis and treatment of cardiorenal syndrome type 1, have been analyzed. The most important role in the occurrence of cardio renal syndrome type 1 is played by hemodynamic mechanisms, activation of neurohumoral systems, inflammation and imbalance between the production of reactive oxygen species (ROS and nitric oxide (NO. Diagnosis of cardiorenal syndrome type 1 involves biomarkers of acute renal injury among which the most important are: neutrophil gelatinaseassociated lipocalin (NGAL, cystatin C, kidney injury molecule 1 (KIM-1, liver-type fatty acid binding protein (L-FABP, IL-18 and the values of nitrogen compounds in serum. In addition to a pharmacological therapy, various modalities of extracorporeal ultrafiltration are applied in treatment of CRS-1, particularly if there is resistance to the use of diuretic therapy. As opposed to the experimental models, in clinical practice acute renal injury is often diagnosed late so that the measures taken do not give the expected results and the protective role shown in experimental conditions do not give the same results. For all these reasons, it is necessary to analyze the pathophysiology of renal impairment in cardiorenal syndrome as well as detect early indicators of kidney injury that could have clinical benefit and positive impact on reducing the cost of treatment.

  2. Hyperglycemia and xerostomia are key determinants of tooth decay in type 1 diabetic mice.

    Science.gov (United States)

    Yeh, Chih-Ko; Harris, Stephen E; Mohan, Sumathy; Horn, Diane; Fajardo, Roberto; Chun, Yong-Hee Patricia; Jorgensen, James; Macdougall, Mary; Abboud-Werner, Sherry

    2012-06-01

    Insulin-dependent type 1 diabetes mellitus (DM) and oral diseases are closely interrelated. Poor metabolic control in diabetics is associated with a high risk of gingivitis, periodontitis and tooth loss. Salivary flow declines in diabetics and patients suffer from xerostomia. Reduced saliva predisposes to enamel hypomineralization and caries formation; however, the mechanisms that initiate and lead to progression of tooth decay and periodontitis in type 1 DM have not been explored. To address this issue, we analyzed tooth morphology in Akita ⁻/⁻ mice that harbor a point mutation in the Ins2 insulin gene, which leads to progressive hyperglycemia. Mandibles from Akita ⁻/⁻ and wild-type littermates were analyzed by microCT, scanning EM and histology; teeth were examined for amelogenin (Amel) and ameloblastin (Ambn) expression. Mice were injected with pilocarpine to assess saliva production. As hyperglycemia may alter pulp repair, the effect of high glucose levels on the proliferation/differentiation of cultured MD10-F2 pulp cells was also analyzed. Results showed that Akita ⁻/⁻ mice at 6 weeks of age showed chalky white incisors that correlated with marked hyperglycemia and impaired saliva production. MicroCT of Akita ⁻/⁻ teeth revealed excessive enamel wearing and hypomineralization; immunostaining for Amel and Ambn was decreased. A striking feature was invasion of dentinal tubules with Streptococcus mitis and microabcesses that originated in the coronal pulp and progressed to pulp necrosis and periapical periodontitis. High levels of glucose also inhibited MD10-F2 cell proliferation and differentiation. Our findings provide the first evidence that hyperglycemia in combination with reduced saliva in a model of type1 DM leads to decreased enamel mineralization/matrix proteins and predisposes to excessive wearing and decay. Importantly, hyperglycemia adversely affects enamel matrix proteins and pulp repair. Early detection and treatment of hyperglycemia

  3. Matrix calculus

    CERN Document Server

    Bodewig, E

    1959-01-01

    Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well

  4. The planar cell polarity protein VANGL2 coordinates remodeling of the extracellular matrix.

    Science.gov (United States)

    Williams, B Blairanne; Mundell, Nathan; Dunlap, Julie; Jessen, Jason

    2012-07-01

    Understanding how planar cell polarity (PCP) is established, maintained, and coordinated in migrating cell populations is an important area of research with implications for both embryonic morphogenesis and tumor cell invasion. We recently reported that the PCP protein Vang-like 2 (VANGL2) regulates the endocytosis and cell surface level of membrane type-1 matrix metalloproteinase (MMP14 or MT1-MMP). Here, we further discuss these findings in terms of extracellular matrix (ECM) remodeling, cell migration, and zebrafish gastrulation. We also demonstrate that VANGL2 function impacts the focal degradation of ECM by human cancer cells including the formation or stability of invadopodia. Together, our findings implicate MMP14 as a downstream effector of VANGL2 signaling and suggest a model whereby the regulation of pericellular proteolysis is a fundamental aspect of PCP in migrating cells.

  5. Effects of angiotensin II type 1 receptor blocker on bones in mice with type 1 diabetes induced by streptozotocin.

    Science.gov (United States)

    Zhang, Yan; Diao, Teng-Yue; Gu, Sa-Sa; Wu, Shu-Yan; Gebru, Yoseph A; Chen, Xi; Wang, Jing-Yu; Ran, Shu; Wong, Man-Sau

    2014-09-01

    This study was performed to address the pathological roles of the skeletal renin-angiotensin system (RAS) in type 1 diabetes-induced osteoporosis and the effects of the angiotensin II type 1 receptor blocker losartan on bones in diabetic mice. Bone histomorphology was detected by H&E staining, Safranin O staining and X-ray radiography. Micro-CT was performed for the analysis of bone parameters. Gene and protein expression were determined by RT-PCR and immunoblotting. Type 1 diabetic mice displayed osteopenia phenotype, and losartan treatment had no osteoprotective effects on diabetic mice as shown by the reduction of bone mineral density and microarchitectural parameters at the proximal metaphysis of the tibia. The mRNA expression of AGT, renin receptor and ACE, and protein expression of renin and AT1R were markedly up-regulated in the bones of vehicle-treated diabetic mice compared to those of non-diabetic mice. The treatment with losartan further significantly increased the expression of AGT, renin, angiotensin II and AT1R, and reduced the expression of AT2R receptor as compared to those of diabetic mice. Local bone RAS functionally played a role in the development of type 1 diabetic osteoporosis, and losartan had no bone-sparing function in diabetes mice because of enhance skeletal RAS activity. © The Author(s) 2013.

  6. Consensus guidelines for management of glycogen storage disease type 1b - European Study on Glycogen Storage Disease Type 1

    NARCIS (Netherlands)

    Visser, G; Rake, JP; Labrune, P; Leonard, JV; Moses, S; Ullrich, K; Wendel, U; Smit, GPA

    2002-01-01

    Life expectancy in glycogen storage disease type 1 (GSD-1) has improved considerably. Its relative rarity implies that no metabolic centre has experience of large series of patients and therefore experience with long-term management and follow-up at each centre is limited. There is wide variation in

  7. VANGL2 interacts with integrin αv to regulate matrix metalloproteinase activity and cell adhesion to the extracellular matrix.

    Science.gov (United States)

    Jessen, Tammy N; Jessen, Jason R

    2017-12-15

    Planar cell polarity (PCP) proteins are implicated in a variety of morphogenetic processes including embryonic cell migration and potentially cancer progression. During zebrafish gastrulation, the transmembrane protein Vang-like 2 (VANGL2) is required for PCP and directed cell migration. These cell behaviors occur in the context of a fibrillar extracellular matrix (ECM). While it is thought that interactions with the ECM regulate cell migration, it is unclear how PCP proteins such as VANGL2 influence these events. Using an in vitro cell culture model system, we previously showed that human VANGL2 negatively regulates membrane type-1 matrix metalloproteinase (MMP14) and activation of secreted matrix metalloproteinase 2 (MMP2). Here, we investigated the functional relationship between VANGL2, integrin αvβ3, and MMP2 activation. We provide evidence that VANGL2 regulates cell surface integrin αvβ3 expression and adhesion to fibronectin, laminin, and vitronectin. Inhibition of MMP14/MMP2 activity suppressed the cell adhesion defect in VANGL2 knockdown cells. Furthermore, our data show that MMP14 and integrin αv are required for increased proteolysis by VANGL2 knockdown cells. Lastly, we have identified integrin αvβ3 as a novel VANGL2 binding partner. Together, these findings begin to dissect the molecular underpinnings of how VANGL2 regulates MMP activity and cell adhesion to the ECM. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Abnormal islet sphingolipid metabolism in type 1 diabetes.

    Science.gov (United States)

    Holm, Laurits J; Krogvold, Lars; Hasselby, Jane P; Kaur, Simranjeet; Claessens, Laura A; Russell, Mark A; Mathews, Clayton E; Hanssen, Kristian F; Morgan, Noel G; Koeleman, Bobby P C; Roep, Bart O; Gerling, Ivan C; Pociot, Flemming; Dahl-Jørgensen, Knut; Buschard, Karsten

    2018-04-18

    Sphingolipids play important roles in beta cell physiology, by regulating proinsulin folding and insulin secretion and in controlling apoptosis, as studied in animal models and cell cultures. Here we investigate whether sphingolipid metabolism may contribute to the pathogenesis of human type 1 diabetes and whether increasing the levels of the sphingolipid sulfatide would prevent models of diabetes in NOD mice. We examined the amount and distribution of sulfatide in human pancreatic islets by immunohistochemistry, immunofluorescence and electron microscopy. Transcriptional analysis was used to evaluate expression of sphingolipid-related genes in isolated human islets. Genome-wide association studies (GWAS) and a T cell proliferation assay were used to identify type 1 diabetes related polymorphisms and test how these affect cellular islet autoimmunity. Finally, we treated NOD mice with fenofibrate, a known activator of sulfatide biosynthesis, to evaluate the effect on experimental autoimmune diabetes development. We found reduced amounts of sulfatide, 23% of the levels in control participants, in pancreatic islets of individuals with newly diagnosed type 1 diabetes, which were associated with reduced expression of enzymes involved in sphingolipid metabolism. Next, we discovered eight gene polymorphisms (ORMDL3, SPHK2, B4GALNT1, SLC1A5, GALC, PPARD, PPARG and B4GALT1) involved in sphingolipid metabolism that contribute to the genetic predisposition to type 1 diabetes. These gene polymorphisms correlated with the degree of cellular islet autoimmunity in a cohort of individuals with type 1 diabetes. Finally, using fenofibrate, which activates sulfatide biosynthesis, we completely prevented diabetes in NOD mice and even reversed the disease in half of otherwise diabetic animals. These results indicate that islet sphingolipid metabolism is abnormal in type 1 diabetes and suggest that modulation may represent a novel therapeutic approach. The RNA expression data is

  9. The skeletal phenotype of achondrogenesis type 1A is caused exclusively by cartilage defects.

    Science.gov (United States)

    Bird, Ian M; Kim, Susie H; Schweppe, Devin K; Caetano-Lopes, Joana; Robling, Alexander G; Charles, Julia F; Gygi, Steven P; Warman, Matthew L; Smits, Patrick J

    2018-01-08

    Inactivating mutations in the ubiquitously expressed membrane trafficking component GMAP-210 (encoded by Trip11 ) cause achondrogenesis type 1A (ACG1A). ACG1A is surprisingly tissue specific, mainly affecting cartilage development. Bone development is also abnormal, but as chondrogenesis and osteogenesis are closely coupled, this could be a secondary consequence of the cartilage defect. A possible explanation for the tissue specificity of ACG1A is that cartilage and bone are highly secretory tissues with a high use of the membrane trafficking machinery. The perinatal lethality of ACG1A prevents investigating this hypothesis. We therefore generated mice with conditional Trip11 knockout alleles and inactivated Trip11 in chondrocytes, osteoblasts, osteoclasts and pancreas acinar cells, all highly secretory cell types. We discovered that the ACG1A skeletal phenotype is solely due to absence of GMAP-210 in chondrocytes. Mice lacking GMAP-210 in osteoblasts, osteoclasts and acinar cells were normal. When we inactivated Trip11 in primary chondrocyte cultures, GMAP-210 deficiency affected trafficking of a subset of chondrocyte-expressed proteins rather than globally impairing membrane trafficking. Thus, GMAP-210 is essential for trafficking specific cargoes in chondrocytes but is dispensable in other highly secretory cells. © 2018. Published by The Company of Biologists Ltd.

  10. Bariatric Surgery in Type 1 Diabetes Mellitus: A Systematic Review.

    Science.gov (United States)

    Mahawar, Kamal K; De Alwis, Nimantha; Carr, William R J; Jennings, Neil; Schroeder, Norbert; Small, Peter K

    2016-01-01

    Bariatric surgery is recognised as an effective treatment strategy for obese patients with type 2 diabetes mellitus. An increasing number of patients with type 1 diabetes mellitus also suffer with obesity and obesity-associated comorbidities but the role of bariatric and metabolic surgery in this group of patients is unclear. This systematic review investigates published English language scientific literature to understand the results of bariatric surgery in obese patients with type 1 diabetes mellitus. We found that these patients can experience significant weight loss and comorbidity resolution with bariatric surgery. Though most patients also see a decline in total insulin requirement, glycaemic control remains difficult. Most of the patients reported in literature have undergone gastric bypass but data is insufficient to recommend any particular procedure.

  11. Solar wind interaction with type-1 comet tails

    International Nuclear Information System (INIS)

    Ershkovich, A.I.

    1977-01-01

    A comet tail is considered as a plasma cylinder separated by a tangential discontinuity surface from the solar wind. Under typical conditions a comet tail boundary is shown to undergo the Kelvin-Helmholtz instability. With infinite amplitude the stabilizing effect of the magnetic field increases, and waves become stable. The proposed model supplies the detailed quantitative description of helical waves observed in type-1 comet tails. This theory enables the evaluation of the comet tail magnetic field by means of the observations of helical waves. The magnetic field in the comet tail turns out to be of the order of the interplanetary field. This conclusion seems to be in accordance with Alfven's idea that the magnetic field in type-1 comet tails is a captured interplanetary field. (Auth.)

  12. Maternal glycemic control and hypoglycemia in type 1 diabetic pregnancy

    DEFF Research Database (Denmark)

    Mathiesen, Elisabeth R; Kinsley, Brendan; Amiel, Stephanie A

    2007-01-01

    OBJECTIVE: To assess the safety and efficacy of insulin aspart (IAsp) versus regular human insulin (HI) in basal-bolus therapy with NPH insulin in pregnant women with type 1 diabetes. RESEARCH DESIGN AND METHODS: Subjects (n = 322) who were pregnant or planning pregnancy were randomized to IAsp...... in basal-bolus therapy with NPH insulin in pregnant women with type 1 diabetes and may potentially offer some benefits in terms of postprandial glucose control and preventing severe hypoglycemia....... or HI as meal-time insulin in an open-label, parallel-group, multicenter study. Subjects had A1C pregnancy. Insulin doses were titrated toward predefined glucose targets and A1C 1C, plasma glucose...

  13. Abnormal islet sphingolipid metabolism in type 1 diabetes

    DEFF Research Database (Denmark)

    Holm, Laurits J; Krogvold, Lars; Hasselby, Jane P

    2018-01-01

    AIMS/HYPOTHESIS: Sphingolipids play important roles in beta cell physiology, by regulating proinsulin folding and insulin secretion and in controlling apoptosis, as studied in animal models and cell cultures. Here we investigate whether sphingolipid metabolism may contribute to the pathogenesis....... Transcriptional analysis was used to evaluate expression of sphingolipid-related genes in isolated human islets. Genome-wide association studies (GWAS) and a T cell proliferation assay were used to identify type 1 diabetes related polymorphisms and test how these affect cellular islet autoimmunity. Finally, we...... diabetes, which were associated with reduced expression of enzymes involved in sphingolipid metabolism. Next, we discovered eight gene polymorphisms (ORMDL3, SPHK2, B4GALNT1, SLC1A5, GALC, PPARD, PPARG and B4GALT1) involved in sphingolipid metabolism that contribute to the genetic predisposition to type 1...

  14. Clustering of microvascular complications in Type 1 diabetes mellitus

    DEFF Research Database (Denmark)

    Bjerg, Lasse; Hulman, Adam; Charles, Morten

    2018-01-01

    AIMS: To describe to what extent microvascular complications exhibit clustering in persons with Type 1 diabetes, and to assess whether the presence of one complication modified the strength of the association between the other two. METHODS: We conducted a cross-sectional analysis of the electronic...... medical records of 2276 persons with Type 1 diabetes treated in a specialized care hospital in Denmark in 2013. We used log-linear analysis to describe associations between diabetic kidney disease, neuropathy and retinopathy and logistic regression models to quantify the magnitude of associations...... adjusting for potential confounders. RESULTS: The median duration of diabetes was 24 years and median HbA1c was 63 mmol/mol (7.9%). We found strong indication of clustering and found no evidence that presence of one complication modified the association between the other two. In models adjusted for diabetes...

  15. Behavioral interventions for adolescents with type 1 diabetes

    DEFF Research Database (Denmark)

    Hampson, S. E.; Skinner, T. C.; Hart, J.

    2000-01-01

    OBJECTIVE - To evaluate the effectiveness of behavioral interventions for adolescents with type 1 diabetes based on a systematic review of the literature. RESEARCH DESIGN AND METHODS - The literature was identified by searching 11 electronic databases, hand-searching 3 journals from their start...... dates, and contacting individual researchers. Only articles that reported evaluations of behavioral (including educational and psychosocial) interventions for adolescents (age range 9-21 years) with type 1 diabetes that included a control group were included in the present review. Data summarizing...... were RCTs. Effect sizes could be calculated for 18 interventions. The overall mean effect size calculated across all outcomes was 0.33 (median 0.21), indicating that these interventions have a small- to medium-sized beneficial effect on diabetes management. Interventions that were theoretically based...

  16. Glucocorticoid receptors in monocytes in type 1 diabetes mellitus

    DEFF Research Database (Denmark)

    Damm, P; Binder, C

    1989-01-01

    Glucocorticoid receptor binding characteristics were investigated in 8 males with poorly controlled Type 1 diabetes mellitus and 14 healthy males. The cell type studied was monocytes, and a method for correction for heterogeneity in glucocorticoid binding in a mononuclear leucocyte population...... or with HbA1c. In conclusion, no major abnormalities in glucocorticoid receptor binding characteristics could be demonstrated in Type 1 diabetes mellitus....... was introduced. The number of receptors and the dissociation constant KD were, respectively, 13,699 and 2.93 X 10(-8) mol/l for the control group and 15,788 and 2.75 X 10(-8) mol/l for diabetics (p greater than 0.05). In diabetics, KD correlated negatively with blood glucose (r = 0.762, p less than 0...

  17. Intervening before the onset of Type 1 diabetes

    DEFF Research Database (Denmark)

    Reimers, Jesper Irving

    2003-01-01

    AIMS/HYPOTHESIS: To set up a clinical trial to establish whether nicotinamide can prevent or delay clinical onset of Type 1 diabetes. METHOD: The European Nicotinamide Diabetes Intervention Trial is a randomised, double-blind, placebo-controlled intervention trial undertaken in 18 European...... countries, Canada and the USA. Entry criteria were a first-degree family history of Type 1 diabetes, age 3-40 years, confirmed islet cell antibody (ICA) levels greater than or equal to 20 JDF units, and a non-diabetic OGTT; the study group was further characterised by intravenous glucose tolerance testing......) centile in 34%. Additional islet autoantibodies were identified in 354 trial entrants. Diabetes-associated HLA class II haplotypes were found in 84% of the younger age group and 80% of the older group. The protective haplotype HLA-DQA1*0102-DQB1*0602 was found in 10% overall. CONCLUSIONS...

  18. Insulin Administration for People with Type 1 diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Finan, Daniel Aaron; Poulsen, Niels Kjølstad

    2011-01-01

    considers meal announcement at mealtimes only. They give a quantitative upper bound on the achievable control performance. The third control strategy is a feedforward-feedback control strategy. This strategy uses a time-varying setpoint to reduce the risk of hypoglycemia. The feedback controller computes......In this paper, we apply model predictive control (MPC) for control of blood glucose in people with type 1 diabetes. The two first control strategies are based on nonlinear model predictive control (NMPC). The first control strategy is based on meal announcement in advance, while the second one...... the optimal basal insulin infusion rate. The feedforward controller consists of a bolus calculator. It computes the optimal bolus, along with the time-varying glucose setpoint. We test these three strategies on a virtual patient with type 1 diabetes. The numerical results demonstrate the robustness...

  19. Bartter Syndrome Type 1 Presenting as Nephrogenic Diabetes Insipidus

    Directory of Open Access Journals (Sweden)

    Gianluca Vergine

    2018-01-01

    Full Text Available Bartter syndrome (BS type 1 (OMIM #601678 is a hereditary salt-losing renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypercalciuria, nephrocalcinosis, polyuria, recurrent vomiting, and growth retardation. It is caused by loss-of-function mutations of the SLC12A1 gene, encoding the furosemide-sensitive Na-K-Cl cotransporter. Recently, a phenotypic variability has been observed in patients with genetically determined BS, including absence of nephrocalcinosis, hypokalemia, and/or metabolic alkalosis in the first year of life as well as persistent metabolic acidosis mimicking distal renal tubular acidosis. We report the case of a child with a genetically determined diagnosis of Bartter syndrome type 1 who presented with a phenotype of nephrogenic diabetes insipidus, with severe hypernatremia and urinary concentrating defect. In these atypical cases, molecular analysis is mandatory to define the diagnosis, in order to establish the correct clinical and therapeutic management.

  20. Bartter Syndrome Type 1 Presenting as Nephrogenic Diabetes Insipidus.

    Science.gov (United States)

    Vergine, Gianluca; Fabbri, Elena; Pedini, Annalisa; Tedeschi, Silvana; Borsa, Niccolò

    2018-01-01

    Bartter syndrome (BS) type 1 (OMIM #601678) is a hereditary salt-losing renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypercalciuria, nephrocalcinosis, polyuria, recurrent vomiting, and growth retardation. It is caused by loss-of-function mutations of the SLC12A1 gene, encoding the furosemide-sensitive Na-K-Cl cotransporter. Recently, a phenotypic variability has been observed in patients with genetically determined BS, including absence of nephrocalcinosis, hypokalemia, and/or metabolic alkalosis in the first year of life as well as persistent metabolic acidosis mimicking distal renal tubular acidosis. We report the case of a child with a genetically determined diagnosis of Bartter syndrome type 1 who presented with a phenotype of nephrogenic diabetes insipidus, with severe hypernatremia and urinary concentrating defect. In these atypical cases, molecular analysis is mandatory to define the diagnosis, in order to establish the correct clinical and therapeutic management.

  1. Therapeutic management of type 1 diabetes before and during pregnancy

    DEFF Research Database (Denmark)

    Mathiesen, Elisabeth R; Damm, Peter; Nielsen, Lene Ringholm

    2011-01-01

    before and during pregnancy is crucial and the prevalence of severe hypoglycemia during pregnancy needs to be reduced. Rapid-acting insulin analogues are regarded as safe to use in pregnancy and studies on long-acting insulin analogues are in the pipeline. Supplementation with folic acid may reduce......Introduction: Pregnancy increases the risks of adverse outcomes for mother and infant in women with type 1 diabetes. Obtaining and maintaining adequate glycemic control during pregnancy is crucial for optimizing outcomes. Areas covered: The importance of prepregnancy planning and treatment during...... pregnancy is reviewed. The use of insulin analogues and antihypertensive drugs in diabetic pregnancy are in focus. The reader is presented with evidence discussing the importance of prepregnancy counseling and treatment during pregnancy in women with type 1 diabetes. Expert opinion: Tight glycemic control...

  2. Multimodal imaging of choroidal nodules in neurofibromatosis type-1

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2018-01-01

    Full Text Available Choroidal nodules in neurofibromatosis type-1 are common and are best imaged with near-infrared reflectance (NIR imaging. The authors describe swept-source optical coherence tomography angiography (SSOCTA of choroidal nodules. These nodules are seen as hyperflow areas on SSOCTA and correlate well to bright patches on NIR imaging. The utility of multicolor scanning laser imaging in detecting these abnormalities is also described.

  3. Can Type 1 Diabetes patients safely fast during Ramadan?

    Directory of Open Access Journals (Sweden)

    M. Hamed Farooqi

    2016-09-01

    Full Text Available The issue whether people with Type 1 Diabetes can safely fast during Ramadan has been the subject of quite a few debates over the years. Had it been a simple "yes" or "no" issue, there would have been no reason to debate. However, like a lot of other topics in medical management, this particular subject overlaps both the science and the art of medicine.

  4. Preventing microvascular complications in type 1 diabetes mellitus

    OpenAIRE

    Viswanathan, Vijay

    2015-01-01

    Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progressi...

  5. Type 1 diabetes : The autoimmune process and islet transplantation

    OpenAIRE

    Jacobson, Stella

    2010-01-01

    Type 1 diabetes (T1D) is an autoimmune disease characterized by the selective loss of the insulin-producing β-cells residing in the islets of Langerhans in the pancreas. Cytokines are involved in diabetes development in the nonobese diabetic (NOD) mouse model. NOD mice over-expressing the suppressor of cytokine signaling (SOCS-1) specifically in the β-cells are protected from T1D. Previous studies showed that immune cells infiltrated the pancreas of SOCS-1-transgenic (tg)...

  6. Kenny-Caffey syndrome type 1 in an Egyptian girl

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    Kotb Abbass Metwalley

    2012-01-01

    Full Text Available Kenny-Caffey syndrome type 1 (KCS1 (OMIM 244460 is a rare syndrome characterized by growth retardation, uniformly small slender long bones with medullary stenosis, thickened cortex of the long bones, hypocalcemia possibly with tetany at an early age and normal intelligence. The primary outcome of KCS1 is short stature. We present here an Egyptian girl aged 32 months with typical feature of KCS1.

  7. Ocular manifestations of Type 1 diabetes mellitus in pediatric population

    Directory of Open Access Journals (Sweden)

    Handan Akil

    2016-01-01

    Full Text Available Context: To evaluate the necessity of ocular screening in Type 1 diabetes mellitus (DM. Aims: This study aims to investigate the diabetes-related ocular changes according to the glycosylated hemoglobin (HbA1c level and duration of diabetes in children and compare the results with nondiabetic healthy children. Settings and Design: Observational cross-sectional study designed by ophthalmology and pediatric endocrinology clinics. Subjects and Methods: Forty-two children with Type 1 DM, 42 healthy gender- and age-matched children as controls were enrolled. All patients underwent ophthalmic and physical examination, with a review of medical history and current medication. HbA1c level, best corrected visual acuity, intraocular pressure (IOP, central corneal thickness (CCT, tear break-up time (BUT, Schirmer test, dilated fundus examination findings, central retinal thickness (CRT, and total macular volume (TMV measurements were noted. Statistical Analysis: Descriptive statistics, Student's t-test, Mann–Whitney U-test, Chi-square test for comparison of the group parameters and correlation analyses (Spearman analysis were performed with SPSS statistical software 17.0 (SPSS Inc., Chicago, IL, USA. Results: Type 1 DM group exhibited significantly reduced Schirmer test, increased IOP and decreased retinal thickness relative to the age-matched control group (P < 0.05 but no statistically significant difference was found for the BUT (P = 0.182 and for the CCT (P = 0.495. The correlations between the age, duration, HbA1c and IOP, BUT, Schirmer test, TMV, CRT measurements did not reach statistical significance. Conclusions: More frequent screening may be needed for complications, including neuropathy-related dry eye syndrome, IOP changes, and diabetic retinopathy in children with Type 1 DM.

  8. Varenicline may trigger severe hypoglycaemia in Type 1 diabetes

    DEFF Research Database (Denmark)

    Kristensen, P.L.; Pedersen-Bjergaard, U.; Thorsteinsson, B.

    2008-01-01

    is important to reduce risk of cardiovascular morbidity, especially in diabetes, use of effective drugs indicated for smoking cessation is rational. Case report We report multiple episodes of severe hypoglycaemia after starting varenicline in a 53-year-old woman with Type 1 diabetes. Since onset of diabetes......, intensified blood glucose monitoring and careful education of patients with diabetes treated with varenicline. Further investigation of the use of varenicline in patients with diabetes is warranted Udgivelsesdato: 2008/5...

  9. Genetic heterogeneity in patients with Bartter syndrome type 1.

    Science.gov (United States)

    Sun, Mingran; Ning, Jing; Xu, Weihong; Zhang, Han; Zhao, Kaishu; Li, Wenfu; Li, Guiying; Li, Shibo

    2017-02-01

    Bartter syndrome (BS) type 1 is an autosomal recessive kidney disorder caused by loss‑of‑function mutations in the solute carrier family 12 member 1 (SLC12A1) gene. To date, 72 BS type 1 patients harboring SLC12A1 mutations have been documented. Of these 144 alleles studied, 68 different disease‑causing mutations have been detected in 129 alleles, and no mutation was detected in the remaining 15 alleles. The mutation types included missense/nonsense mutations, splicing mutations and small insertions and deletions ranging from 1 to 4 nucleotides. A large deletion encompassing a whole exon in the SLC12A1 gene has not yet been reported. The current study initially identified an undocumented homozygous frameshift mutation (c.1833delT) by Sanger sequencing analysis of a single infant with BS type 1. However, in a subsequent analysis, the mutation was detected only in the father's DNA. Upon further investigation using a next‑generation sequencing approach, a deletion in exons 14 and 15 in both the patient and patient's mother was detected. The deletion was subsequently confirmed by use of a long‑range polymerase chain reaction and was determined to be 3.16 kb in size based on sequencing of the junction fragment. The results of the present study demonstrated that pathogenic variants of SLC12A1 are heterogeneous. Large deletions appear to serve an etiological role in BS type 1, and may be more prevalent than previously thought.

  10. Coexistence of Ankylosing Spondylitis and Neurofibromatosis Type 1.

    Science.gov (United States)

    Gundogdu, Baris; Yolbas, Servet; Yildirim, Ahmet; Gonen, Murat; Koca, Suleyman Serdar

    2016-01-01

    Ankylosing spondylitis (AS) is a systemic disease primarily characterized by the inflammation of sacroiliac joints and axial skeleton. Neurofibromatosis type 1 (NF1) is a multisystem genetic disease which is characterized by cutaneous findings, most importantly café-au-lait spots and axillary freckling, by skeletal dysplasia, and by the growth of both benign and malignant nervous system neoplasms, most notably benign neurofibromas. In this case report, we present a 43-year-old male with AS and NF1.

  11. Type 1 diabetes mellitus and exercise in competitive athletes.

    Science.gov (United States)

    Ratjen, I; Weber, K S; Roden, M; Herrmann, M-E; Müssig, K

    2015-07-01

    The number of patients with type 1 diabetes mellitus who are actively participating in competitive sports is increasing. Here, we aimed to assess individual experiences of competitive athletes with type 1 diabetes and to compare these experiences with current recommendations. A survey of 20 competitive athletes with type 1 diabetes, categorized as endurance (n=10) and non-endurance (n=10) athletes, was performed. Endurance and non-endurance athletes did not differ in gender distribution, age, body mass index, and known diabetes duration. Self-reported target blood glucose values prior to exercise were lower in non-endurance than in endurance athletes (195±34 vs. 137±28 mg/dl, P=0.001). The majority of all athletes experienced activity-induced hypo- and hyperglycemic events, independently of exercise type. However, endurance athletes used additional carbohydrate units to prevent activity-induced hypoglycemic events more frequently without monitoring their blood glucose levels than non-endurance athletes (50% vs. 0%, P=0.01). The reduction of the insulin dose on training and competition days compared to days without exercise was similar for endurance and non-endurance athletes. These results point to a very individual adaption of the athlete's therapy during training and competition. However, there are distinct differences in diabetes management between endurance and non-endurance athletes. © Georg Thieme Verlag KG Stuttgart · New York.

  12. [Prerenal kidney failure in type 1 diabetes mellitus].

    Science.gov (United States)

    Schloot, N C; Hübinger, A; Scherbaum, W A

    2003-12-05

    A 22-year-old man was admitted in a severely reduced condition. Type 1 diabetes mellitus had been diagnosed when he was 13 years old, hypothyroidism was treated with L-thyroxine for 2 years. For the past 3 years he suffered from repetitive hypoglycemia, combined with vertigo, weakness and low blood pressure. He presented with hypotension and hyperpigmentation of the skin. Pathological laboratory results were: serum creatinine 2.5 mg/dl; urea 145 mg/dl; sodium 124 mmol/l; potassium 8.3 mmol/l, HbA (1c) 9.1%. The ECG showed large T waves. Additionally, plasma aldosterone was decreased (diabetes mellitus type 1 and hypothyroidism (Schmidt-Carpenter-Syndrome) were diagnosed. Initially, the patient was treated with sodium chloride 0.9% i. v. and oral sodium 5 g 4 times/day. In addition, he was given hydrocortisone 100 mg i. v., and then switched to 40 mg per day (20-10-10 mg), fludrocortisone 0.05 mg/ day and L-thyroxine 75 microg/ day orally the clinical condition improved dramatically within 24 hours. Intensified conventional insulin therapy was continued. In patients with type 1 diabetes, especially in combination with associated organ-specific autoimmune diseases, autoimmune polyglandular syndrome should be considered and adequately treated with those hormones that are reduced.

  13. Diabetes Distress Among Persons With Type 1 Diabetes.

    Science.gov (United States)

    Powers, Margaret A; Richter, Sara A; Ackard, Diann M; Craft, Cheryl

    2017-02-01

    Purpose The purpose of this study is to evaluate associations between diabetes distress and a range of psychological health behaviors and concerns among persons with type 1 diabetes for the benefit of enhancing early identification and intervention of at-risk individuals. Methods Persons with type 1 diabetes (n = 268; 57.1% female, 91.0% white, 76.8% satisfaction with life, self-esteem, self-efficacy, depression, perfectionism, body image satisfaction, dietary restraint and eating, and shape and weight concerns. Each subscale score was compared within age groups (depression scores and eating, and shape and weight concerns than those with low or moderate distress. For patients satisfaction with life, self-esteem, and self-efficacy and higher on dietary restraint and several areas of perfectionism than those with low or moderate distress. Conclusions Individuals with type 1 diabetes who have high diabetes distress also report higher A1C values and poorer psychological health concerns. A brief diabetes distress questionnaire can help to identify those who need additional screening, education and support, and treatment for overall health and well-being.

  14. Usher syndrome type 1: early detection of electroretinographic changes.

    Science.gov (United States)

    Flores-Guevara, Roberto; Renault, Francis; Loundon, Natalie; Marlin, Sandrine; Pelosse, Béatrice; Momtchilova, Martha; Auzoux-Chevé, Monique; Vermersch, Anne Isabelle; Richard, Pascal

    2009-11-01

    Usher syndrome type 1 needs to be diagnosed at early age in order to timely manage speech therapy, cochlear implantation, and genetic counseling. Few data are available regarding electroretinographic testing before the age of six years. To describe electroretinographic changes in young children with Usher syndrome type 1. Retrospective study of fourteen patients. Age at first neurophysiologic testing was between 17 months and 5 years 4 months. Electroretinogram was performed using flash stimulation in mesopic conditions in the conscious child. Analysis was focused on the amplitudes and latencies of a- and b-waves. Whatever the age, an abnormal fundus was always confirmed with an absent electroretinogram. The youngest patient with absent electroretinogram was 17 month-old. When recorded on and after the 29th month of age, electroretinogram was absent in all cases, including 6 patients with normal fundus. In three patients a low-amplitude electroretinogram was present at first recording within the 26th and 27th months. Electroretinogram showed retinopathy in young children with Usher syndrome type 1, even in the absence of fundoscopic signs of retinal degeneration.

  15. Trabecular bone histomorphometry in humans with Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Armas, Laura A G; Akhter, Mohammed P; Drincic, Andjela; Recker, Robert R

    2012-01-01

    Patients with Type 1 Diabetes Mellitus (DM) have markedly increased risk of fracture, but little is known about abnormalities in bone microarchitecture or remodeling properties that might give insight into the pathogenesis of skeletal fragility in these patients. We report here a case-control study comparing bone histomorphometric and micro-CT results from iliac biopsies in 18 otherwise healthy subjects with Type 1 Diabetes Mellitus with those from healthy age- and sex-matched non-diabetic control subjects. Five of the diabetics had histories of low-trauma fracture. Transilial bone biopsies were obtained after tetracycline labeling. The biopsy specimens were fixed, embedded, and scanned using a desktop μCT at 16 μm resolution. They were then sectioned and quantitative histomorphometry was performed as previously described by Recker et al. [1]. Two sections, >250 μm apart, were read from the central part of each biopsy. Overall there were no significant differences between diabetics and controls in histomorphometric or micro-CT measurements. However, fracturing diabetics had structural and dynamic trends different from nonfracturing diabetics by both methods of analysis. In conclusion, Type 1 Diabetes Mellitus does not result in abnormalities in bone histomorphometric or micro-CT variables in the absence of manifest complications from the diabetes. However, diabetics suffering fractures may have defects in their skeletal microarchitecture that may underlie the presence of excess skeletal fragility. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Glutaric aciduria type 1: neuroimaging features with clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad, Shaimaa Abdelsattar; Ahmed, Khaled A. [Ain-Shams University, Department of Radiodiagnosis, Faculty of Medicine, Cairo (Egypt); Abdelkhalek, Heba Salah; Zaki, Osama K. [Ain-Shams University, Medical Genetics Unit, Pediatric Department, Faculty of Medicine, Cairo (Egypt)

    2015-10-15

    Glutaric aciduria type 1 is a rare neurometabolic disease with high morbidity. To describe the MR imaging abnormalities in glutaric aciduria type 1 and to identify any association between the clinical and imaging features. MRI scans of 29 children (mean age: 16.9 months) with confirmed diagnosis of glutaric aciduria type 1 were retrospectively reviewed. Gray matter and white matter scores were calculated based on a previously published pattern-recognition approach of assessing leukoencephalopathies. Hippocampal formation and opercular topography were assessed in relation to the known embryological basis. MRI scores were correlated with morbidity score. The most consistent MRI abnormality was widened operculum with dilatation of the subarachnoid spaces surrounding underdeveloped frontotemporal lobes. Incomplete hippocampal inversion was also seen. The globus pallidus was the most frequently involved gray matter structure (86%). In addition to the central tegmental tract, white matter abnormalities preferentially involved the central and periventricular regions. The morbidity score correlated with the gray matter abnormality score (P = 0.004). Patients with dystonia had higher gray matter and morbidity scores. Morbidity is significantly correlated with abnormality of gray matter, rather than white matter, whether secondary to acute encephalopathic crisis or insidious onset disease. (orig.)

  17. Efficacy and safety of sotagliflozin in treating diabetes type 1.

    Science.gov (United States)

    Rendell, Marc S

    2018-02-01

    Sotagliflozin is the first dual SGLT1/SGLT2 inhibitor developed for use in diabetes. Sotagliflozin blocks SGLT2 in the kidneys and SGLT1 in the intestines resulting in reduced early phase glucose absorption and increased blood levels of GLP-1 and PYY. Urinary glucose excretion is lower than with other agents as a result of decreased glucose absorption. The primary development effort to date has been in Type 1 diabetes. Areas covered: The published information on sotagliflozin is reviewed, along with the recent results of several pivotal Type 1 diabetes trials. Expert opinion: Sotagliflozin treatment lowers HbA1c and reduces glucose variability, with a trend to less hypoglycemic events. In the Type 1 trials, sotagliflozin treated individuals experienced DKA at a higher rate than placebo treated patients. An additional safety issue arises from the as yet unknown potential risks in women of child bearing potential in whom DKA is of utmost concern. The sotagliflozin development program has now been extended to trials in Type 2 diabetes, and long term studies will be needed to assess the benefits and risks of the agent in comparison to other currently marketed SGLT2 inhibitors.

  18. Introduction of Molecular Diagnosis of Hemochromatosis Type 1 in Cuba

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    Ismael Aramís Cervera García

    2013-06-01

    Full Text Available Background: hemochromatosis type 1 is an autosomal recessive genetic disorder, which should be diagnosed during its preclinical phase in order to prevent severe organ damage. Objective: to establish the diagnosis of hemochromatosis type 1 in Cuba, and calculate its frequencies in patients with hepatopathies. Methods: an analytic cross-sectional study was conducted including 65 patients with liver disease, who were referred to the laboratory of Molecular Biology of the National Medical Genetics Center by clinical geneticists. A PCR-RFLP analysis was used for detecting the C282Y and H63D mutations in the HFE gene. Results: PCR-RFLP analysis was standardized for the detection of C282Y and H63D mutations. Frequencies of C282Y and H63D mutations in the HFE gene in patients with hepatopathies were 6.3% and 18.2% respectively. Conclusions: molecular diagnosis of C282Y and H63D mutations in the HFE gene causing hemochromatosis type 1 contributed to the identification of 28 carriers in the 65 patients who were studied, as well as a homozygous individual for the H63D mutation, which shows the high prevalence of these mutations in Cuban patients with liver disease.

  19. Frequency of Ketoacidosis in Newly Diagnosed Type 1 Diabetic Children

    Science.gov (United States)

    Razavi, Zahra

    2010-01-01

    Objectives Diabetic ketoacidosis (DKA) is the leading cause of morbidity and mortality in children with type 1 diabetes mellitus (TIDM). Many patients with newly diagnosed type 1 diabetes present with DKA. The aim of this study is to determine the frequency and the clinical presentation of diabetic ketoacidosis at the diagnosis of type 1 diabetes mellitus in youths in hamadan, Western Province of Iran. Methods The Clinical and laboratory data of a total of 200 patients under 19 years of age with newly diagnosed type 1 diabetes mellitus between 1995-2005 were retrospectively reviewed. Statistical analysis was performed using SPSS 11. Results 48 (24%)of the children were presented in a state of ketoacidosis. Sever form of DKA (pH≤7.2) was observed in 54.5% of patients. The mean age at diagnosis was 7.3±5.15 years in DKA group and 8.59±3.07 in non-DKA group (p=0.22). 60.4% of patient with DKA were female whereas in the non-DKA group, 53.3% of patients were female, the difference was not significant (p=0.38). The duration of symptoms before diagnosis was 14.84±8.19 days in patients with DKA and 22.39±2.27 in the non-DKA group, (p=0.11). No significant difference was found between the age, sex and duration of the symptoms and occurance of DKA. Polydipsia (85.4) polyuria (83.3%), weakness (68.8%) and abdominal pain (52.1%) were the most frequently notified symptoms among the patients. In two cases, diagnosis of DKA was preceded by as appendicitis and the patient underwent appendectomy. Conclusion Frequency of DKA at onset of type 1 diabetes mellitus was significant in the studied region. However, it was lower than other regions in Asia. Polydipsia, polyuria, fatigue and abdominal pain were the most common symptoms on presentation. PMID:22125712

  20. Frequency of Ketoacidosis in Newly Diagnosed Type 1 Diabetic Children

    Directory of Open Access Journals (Sweden)

    Zahra Razavi

    2010-04-01

    Full Text Available ABSTRACTObjectives: Diabetic ketoacidosis (DKA is the leading cause of morbidity and mortality in children with type 1 diabetes mellitus (TIDM. Many patients with newly diagnosed type 1 diabetes present with DKA. The aim of this study is to determine the frequency and the clinical presentation of diabetic ketoacidosis at the diagnosis of type 1 diabetes mellitus in youths in hamadan, Western Province of Iran.Methods: The Clinical and laboratory data of a total of 200 patients under 19 years of age with newly diagnosed type 1 diabetes mellitus between 1995-2005 were retrospectively reviewed. Statistical analysis was performed using SPSS 11.Results: 48 (24%of the children were presented in a state of ketoacidosis. Sever form of DKA (pH≤7.2 was observed in 54.5% of patients. The mean age at diagnosis was 7.3±5.15 years in DKA group and 8.59±3.07 in non-DKA group (p=0.22. 60.4% of patient with DKA were female whereas in the non-DKA group, 53.3% of patients were female, the difference was not significant (p=0.38. The duration of symptoms before diagnosis was 14.84±8.19 days in patients with DKA and 22.39±2.27 in the non-DKA group, (p=0.11. No significant difference was found between the age, sex and duration of the symptoms and occurance of DKA. Polydipsia (85.4 polyuria (83.3%, weakness (68.8% and abdominal pain (52.1% were the most frequently notified symptoms among the patients. In two cases, diagnosis of DKA was preceded by as appendicitis and the patient underwent appendectomy.Conclusion: Frequency of DKA at onset of type 1 diabetes mellitus was significant in the studied region. However, it was lower than other regions in Asia. Polydipsia, polyuria, fatigue and abdominal pain were the most common symptoms on presentation.

  1. Polypropilene nuclear track membranes - a new type of membranes for cleaning and analysis of agressive media

    International Nuclear Information System (INIS)

    Apel', P.Yu.; Shirkova, V.V.; Soboleva, T.I.; Kuznetsov, V.I.; Shestakov, V.D.

    1988-01-01

    The brief description of the polypropylene nuclear track membranes is given. The membranes are obtained from biaxially oriented polypropylene films 10μm thick by means of irradiation with accelerated heavy ions and following chemical etching. The data on pore shape, pore size dispersion, the permeability of membranes and on the content of impurities in membrane matrix are given. It is noted that the polypropylene membranes can be used for cleaning and analysis of agressive chemical species. 9 refs.; 2 figs

  2. Prediction of First Cardiovascular Disease Event in Type 1 Diabetes Mellitus: The Steno Type 1 Risk Engine.

    Science.gov (United States)

    Vistisen, Dorte; Andersen, Gregers Stig; Hansen, Christian Stevns; Hulman, Adam; Henriksen, Jan Erik; Bech-Nielsen, Henning; Jørgensen, Marit Eika

    2016-03-15

    Patients with type 1 diabetes mellitus are at increased risk of developing cardiovascular disease (CVD), but they are currently undertreated. There are no risk scores used on a regular basis in clinical practice for assessing the risk of CVD in type 1 diabetes mellitus. From 4306 clinically diagnosed adult patients with type 1 diabetes mellitus, we developed a prediction model for estimating the risk of first fatal or nonfatal CVD event (ischemic heart disease, ischemic stroke, heart failure, and peripheral artery disease). Detailed clinical data including lifestyle factors were linked to event data from validated national registers. The risk prediction model was developed by using a 2-stage approach. First, a nonparametric, data-driven approach was used to identify potentially informative risk factors and interactions (random forest and survival tree analysis). Second, based on results from the first step, Poisson regression analysis was used to derive the final model. The final CVD prediction model was externally validated in a different population of 2119 patients with type 1 diabetes mellitus. During a median follow-up of 6.8 years (interquartile range, 2.9-10.9) a total of 793 (18.4%) patients developed CVD. The final prediction model included age, sex, diabetes duration, systolic blood pressure, low-density lipoprotein cholesterol, hemoglobin A1c, albuminuria, glomerular filtration rate, smoking, and exercise. Discrimination was excellent for a 5-year CVD event with a C-statistic of 0.826 (95% confidence interval, 0.807-0.845) in the derivation data and a C-statistic of 0.803 (95% confidence interval, 0.767-0.839) in the validation data. The Hosmer-Lemeshow test showed good calibration (P>0.05) in both cohorts. This high-performing CVD risk model allows for the implementation of decision rules in a clinical setting. © 2016 American Heart Association, Inc.

  3. ROLE OF MASTOIDECTOMY IN TYPE 1 TYMPANOPLASTY OF SAFE TYPE CHRONIC SUPPURATIVE OTITIS MEDIA- A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Sami Ullah

    2016-12-01

    Full Text Available BACKGROUND Chronic Suppurative Otitis Media (CSOM is one of the most common diseases of younger age in middle class population of the developing countries. Loss of hearing due to CSOM has a role in learning and intelligence of the students. There are multiple factors, which affect the tympanic membrane repair, mastoidectomy is one. MATERIALS AND METHODS This study at Era’s Lucknow Medical College and Hospital was planned to assess the effect of cortical mastoidectomy in safe type CSOM. For that, 120 patients were taken who were divided in two groups of 60 each. One group was subjected to tympanoplasty type 1 and other to cortical mastoidectomy and type 1 tympanoplasty. RESULTS After six months of follow up, it was found that graft rejection was 13 in group 1 compared to 12 in group2 and cortical mastoidectomy has almost no effect on graft acceptance and hearing gain in pure tone audiometry. CONCLUSION This study was planned to find the effect of cortical mastoidectomy in tympanoplasty type 1 in safe type CSOM. Two groups of 60 patients were taken. In one group, only tympanoplasty type 1 while in other cortical mastoidectomy along with tympanoplasty type 1 was done. After 6 months of follow up, no statistically significant difference was found in the graft rejection and hearing gain between the two groups.

  4. Characterization of soluble glycoprotein D-mediated herpes simplex virus type 1 infection

    International Nuclear Information System (INIS)

    Tsvitov, Marianna; Frampton, Arthur R.; Shah, Waris A.; Wendell, Steven K.; Ozuer, Ali; Kapacee, Zoher; Goins, William F.; Cohen, Justus B.; Glorioso, Joseph C.

    2007-01-01

    Herpes simplex virus type 1 (HSV-1) entry into permissive cells involves attachment to cell-surface glycosaminoglycans (GAGs) and fusion of the virus envelope with the cell membrane triggered by the binding of glycoprotein D (gD) to cognate receptors. In this study, we characterized the observation that soluble forms of the gD ectodomain (sgD) can mediate entry of gD-deficient HSV-1. We examined the efficiency and receptor specificity of this activity and used sequential incubation protocols to determine the order and stability of the initial interactions required for entry. Surprisingly, virus binding to GAGs did not increase the efficiency of sgD-mediated entry and gD-deficient virus was capable of attaching to GAG-deficient cells in the absence of sgD. These observations suggested a novel binding interaction that may play a role in normal HSV infection

  5. Smooth muscle antibodies and type 1 autoimmune hepatitis.

    Science.gov (United States)

    Muratori, Paolo; Muratori, Luigi; Agostinelli, Daniela; Pappas, Georgios; Veronesi, Lorenza; Granito, Alessandro; Cassani, Fabio; Terlizzi, Paolo; Lenzi, Marco; Bianchi, Francesco B

    2002-12-01

    Smooth muscle antibodies (SMA) characterize type 1 autoimmune hepatitis. Our aim was to evaluate sensitivity and specificity of different immunofluorescence substrates for the detection of SMA. Sera from 55 patients with type 1 AIH 20 with primary biliary cirrhosis, 20 with HCV-related chronic hepatitis and 25 blood donors were studied for SMA and anti-microfilaments reactivity by immunofluorescence on rat tissue sections, cultured fibroblasts and commercially available HEp-2 cells (collectively revealing the so called anti-actin pattern), and for the XR1 system by counterimmunoelectrophoresis. SMA was classified on the basis of its immunofluorescence pattern (V--vessels, G--glomerular, T--tubular). As further control group, we studied 26 patients with a diagnosis other than AIH, selected on the basis of a SMA-non-T/XR1 positivity. In patients with AIH the SMA-T pattern on rodent tissue, and anti-MF on fibroblasts and on HEp-2 cells were present in 80, 82 and 80%, respectively. Five out of 11 SMA-non T positive AIH patients were anti-MF positive. None of the pathological and healthy controls was positive for SMA-T or anti-MF reactivity. XR1 system was present in 84% of AIH patients and in 5% of pathological controls (p = 0.01). Two out of 26 SMA-non-T/XR1 positive sera were positive for anti-MF by fibroblasts and HEp-2 cells. A significant correlation was found between SMA-T pattern and anti-MF reactivity; no correlation was found between XR1 system and SMA-T pattern or anti-MF reactivity. SMA-T pattern is highly sensitive and specific first diagnostic test for type 1 AIH; anti-MF can be used as additional tool for the diagnosis, particularly when, despite the absence of the SMA-T pattern, AIH is strongly suspected.

  6. Matrix thermalization

    International Nuclear Information System (INIS)

    Craps, Ben; Evnin, Oleg; Nguyen, Kévin

    2017-01-01

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  7. Matrix thermalization

    Science.gov (United States)

    Craps, Ben; Evnin, Oleg; Nguyen, Kévin

    2017-02-01

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  8. Matrix thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)

    2017-02-08

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  9. Coexistence of Ankylosing Spondylitis and Neurofibromatosis Type 1

    Directory of Open Access Journals (Sweden)

    Baris Gundogdu

    2016-01-01

    Full Text Available Ankylosing spondylitis (AS is a systemic disease primarily characterized by the inflammation of sacroiliac joints and axial skeleton. Neurofibromatosis type 1 (NF1 is a multisystem genetic disease which is characterized by cutaneous findings, most importantly café-au-lait spots and axillary freckling, by skeletal dysplasia, and by the growth of both benign and malignant nervous system neoplasms, most notably benign neurofibromas. In this case report, we present a 43-year-old male with AS and NF1.

  10. Early risk stratification in pediatric type 1 diabetes

    DEFF Research Database (Denmark)

    Broe, Rebecca

    2015-01-01

    In the late 1980s all Danish children with type 1 diabetes were invited for a nationwide evaluation of glycemic control. Approximately 75% (n = 720) participated and have later been referred to as The Danish Cohort of Pediatric Diabetes 1987 (DCPD1987). The results were surprisingly poor glycemic...... control among these young patients which lead to a great emphasis on glycemic control in the Danish Pediatric Departments. In 1995 the participants were invited for yet another evaluation but this time with main focus on early signs of microvascular complications - 339 participated. The mean HbA1c had...

  11. Overnight glucose control in people with type 1 diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Duun-Henriksen, Anne Katrine; Schmidt, Signe

    2018-01-01

    This paper presents an individualized model predictive control (MPC) algorithm for overnight blood glucose stabilization in people with type 1 diabetes (T1D). The MPC formulation uses an asymmetric objective function that penalizes low glucose levels more heavily. We compute the model parameters...... algorithm uses frequent glucose measurements from a continuous glucose monitor (CGM) and its decisions are implemented by a continuous subcutaneous insulin infusion (CSII) pump. We provide guidelines for tuning the control algorithm and computing the Kalman gain in the linear state space model in innovation...

  12. Canine adenovirus type 1 in a fennec fox (Vulpes zerda).

    Science.gov (United States)

    Choi, Jeong-Won; Lee, Hyun-Kyoung; Kim, Seong-Hee; Kim, Yeon-Hee; Lee, Kyoung-Ki; Lee, Myoung-Heon; Oem, Jae-Ku

    2014-12-01

    A 10-mo-old female fennec fox (Vulpes zerda) with drooling suddenly died and was examined postmortem. Histologic examination of different tissue samples was performed. Vacuolar degeneration and diffuse fatty change were observed in the liver. Several diagnostic methods were used to screen for canine parvovirus, canine distemper virus, canine influenza virus, canine coronavirus, canine parainfluenza virus, and canine adenovirus (CAdV). Only CAdV type 1 (CAdV-1) was detected in several organs (liver, lung, brain, kidney, spleen, and heart), and other viruses were not found. CAdV-1 was confirmed by virus isolation and nucleotide sequencing.

  13. [SPECIFIC CLINICAL FEATURES OF TYPE 1 AUTOIMMUNE POLYGLANDULAR SYNDROME].

    Science.gov (United States)

    Mikhina, M S; Molashenko, N V; Troshina, E A; Orlova, E M; Sozaeva, L S; Eystein, S H; Breivik, S

    2015-01-01

    Autoimmune polyglandular syndrome is a primary autoimmune disorder affecting two or more peripheral endocrine glands and responsible for their incompetence. It is frequently combined with various organ-specific non-endocrine diseases. Patients with this pathology need life-long replacement therapy and dynamic observation by endocrinologists and other specialists to monitor the effectiveness of the treatment and detect new components of the disease. We report a variant of type 1 autoimmune polyglandular syndrome. Special emphasis is laid on the importance of succession of actions of endocrinologists and specialists in related medical disciplines dealing with children and adult patients.

  14. Burning mouth syndrome due to herpes simplex virus type 1.

    Science.gov (United States)

    Nagel, Maria A; Choe, Alexander; Traktinskiy, Igor; Gilden, Don

    2015-04-01

    Burning mouth syndrome is characterised by chronic orofacial burning pain. No dental or medical cause has been found. We present a case of burning mouth syndrome of 6 months duration in a healthy 65-year-old woman, which was associated with high copy numbers of herpes simplex virus type 1 (HSV-1) DNA in the saliva. Her pain resolved completely after antiviral treatment with a corresponding absence of salivary HSV-1 DNA 4 weeks and 6 months later. 2015 BMJ Publishing Group Ltd.

  15. Type 1 diabetes and Ramadan fasting: A narrative review

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-03-01

    Full Text Available Ramadan fasting is an important pillars of Islam .although patients and children expected from fasting during Ramadan, but every diabetic adolescents intends to fast should consult his diabetes management time, and intensive monitoring of blood glucose and urine ketones .close observation by endocrinologist, and weekly follow- up and highly individualized planning for each diabetic person is essential. In this Article we described general role that should be considered by type 1 diabetic people if they want to be fast during Ramadan.

  16. Diabetes Distress Among Adolescents with Type 1 Diabetes

    DEFF Research Database (Denmark)

    Hagger, Virginia; Hendrieckx, Christel; Sturt, Jackie

    2016-01-01

    with type 1 diabetes: the prevalence of DD; demographic, clinical, behavioral and psychosocial correlates of DD and interventions that reduce DD. Consistent with adult studies, around one third of adolescents experience elevated DD and this is frequently associated with suboptimal glycemic control, low self......Diabetes distress (DD) refers to the negative emotions arising from living with diabetes and the burden of self-management. Among adults, the prevalence and significance of DD are well established, but this is not the case among adolescents. This systematic review investigated among adolescents...

  17. Muscle phenotype in patients with myotonic dystrophy type 1

    DEFF Research Database (Denmark)

    Andersen, Anne Grete Kielgast; Orngreen, Mette C; Preisler, Nicolai Rasmus

    2012-01-01

    Introduction: The pathogenesis of muscle involvement in patients with myotonic dystrophy type 1 (DM1) is not well understood. In this study, we characterized the muscle phenotype in patients with confirmed DM1. Methods: In 38 patients, muscle strength was tested by hand-held dynamometry. Myotonia...... was evaluated by a handgrip test and by analyzing the decrement of the compound muscle action potential. Muscle biopsies were assessed for morphological changes and Na(+) -K(+) pump content. Results: Muscle strength correlated with a decline in Na(+) -K(+) pump content (r = 0.60, P

  18. Early feeding and risk of type 1 diabetes

    DEFF Research Database (Denmark)

    Knip, Mikael; Virtanen, Suvi M; Becker, Dorothy

    2011-01-01

    recruited 5606 newborn infants with a family member affected by type 1 diabetes and enrolled 2159 eligible subjects who carried a risk-conferring HLA genotype. All recruited mothers were encouraged to breastfeed. The intervention lasted for 6-8 mo with a minimum study formula exposure time of 2 mo......, and hydrolyzed casein and standard cow milk-based weaning formulas were compared. Eighty percent of the participants were exposed to the study formula. The overall retention rate over the first 5 y was 87%, and protocol compliance was 94%. The randomization code will be opened when the last recruited child turns...

  19. Fabrication and evaluation of novel zeolite membranes to control the neoplastic activity and anti-tumoral drug treatments in human breast cancer cells. Part 1: Synthesis and characterization of Pure Zeolite Membranes and Mixed Matrix Membranes for adhesion and growth of cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Tavolaro, Palmira, E-mail: p.tavolaro@unical.it [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cubo 4/c, 87036 Rende (Italy); Martino, Guglielmo [Department Di.B.E.S.T. (Biologia, Ecologia, Scienze della Terra), Unit of Physiology, University of Calabria, Cubo 4/c, 87036 Rende (Italy); Andò, Sebastiano [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cubo 4/c, 87036 Rende (Italy); Tavolaro, Adalgisa [Research Institute on Membrane Technology, Unit of Zeolite Membranes, ITM-CNR, University of Calabria, Cubo 17/c, 87036 Rende (Italy)

    2016-12-01

    Novel pure and hybrid zeolite membranes were prepared with appropriate different physicochemical characteristics such as frameworks, hydrophilicity, crystal size, chemical composition, acid-base properties (Point of Zero Charge, PZC) and surface morphology and used in inorganic cell/scaffold constructs. Because the control of cell interactions, as the adhesion, proliferation, remodelling and mobility, is important for differentiation and progression of tumors, this work focused on response of cancer cells adhered and grown on synthesized zeolite surfaces in order to study the influence of these scaffolds in controlled conditions. We have selected the MCF-7 and MDA-MB-231 human breast cancer cell line as model tumor cell lines. This study showed that all the zeolite membranes synthesized are excellent scaffolds because they are very selective materials to support the adhesion and growth of neoplastic cells. All zeolite scaffolds were characterized by FESEM, FTIR ATR, XRD, AFM, PZC and contact angle analyses. Cell adhesion, viability and morphology were measured by count, MTT assay and FESEM microphotography analysis, at various incubation times. - Highlights: • Novel pure and hybrid zeolite scaffolds were developed. • PZMs and MMMs were characterized and used with human cancer cells. • A systematic study of zeolite scaffolds influence on cell adhesion and morphology was performed. • The PZC value of zeolite membranes controls the cell-cell and scaffold-cell interactions.

  20. Fabrication and evaluation of novel zeolite membranes to control the neoplastic activity and anti-tumoral drug treatments in human breast cancer cells. Part 1: Synthesis and characterization of Pure Zeolite Membranes and Mixed Matrix Membranes for adhesion and growth of cancer cells

    International Nuclear Information System (INIS)

    Tavolaro, Palmira; Martino, Guglielmo; Andò, Sebastiano; Tavolaro, Adalgisa

    2016-01-01

    Novel pure and hybrid zeolite membranes were prepared with appropriate different physicochemical characteristics such as frameworks, hydrophilicity, crystal size, chemical composition, acid-base properties (Point of Zero Charge, PZC) and surface morphology and used in inorganic cell/scaffold constructs. Because the control of cell interactions, as the adhesion, proliferation, remodelling and mobility, is important for differentiation and progression of tumors, this work focused on response of cancer cells adhered and grown on synthesized zeolite surfaces in order to study the influence of these scaffolds in controlled conditions. We have selected the MCF-7 and MDA-MB-231 human breast cancer cell line as model tumor cell lines. This study showed that all the zeolite membranes synthesized are excellent scaffolds because they are very selective materials to support the adhesion and growth of neoplastic cells. All zeolite scaffolds were characterized by FESEM, FTIR ATR, XRD, AFM, PZC and contact angle analyses. Cell adhesion, viability and morphology were measured by count, MTT assay and FESEM microphotography analysis, at various incubation times. - Highlights: • Novel pure and hybrid zeolite scaffolds were developed. • PZMs and MMMs were characterized and used with human cancer cells. • A systematic study of zeolite scaffolds influence on cell adhesion and morphology was performed. • The PZC value of zeolite membranes controls the cell-cell and scaffold-cell interactions.