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Sample records for enhanced thymidine uptake

  1. OBSERVATIONS ON THE UPTAKE OF TRITIATED THYMIDINE IN THE PRONUCLEI OF FERTILIZED SAND DOLLAR EMBRYOS

    Science.gov (United States)

    Simmel, Eva B.; Karnofsky, David A.

    1961-01-01

    Following fertilization of the egg of the sand dollar Echinarachnius parma, tritiated thymidine (H3TDR) was taken up independently by the male and female pronuclei beginning within about 15 to 20 minutes, and the labeled pronuclei fused at about 30 to 40 minutes. At cleavage 90 minutes later the labeled nuclear material was distributed to both daughter cells. Unfertilized eggs and sperm exposed to H3TDR did not show nuclear localization of thymidine. DNA replication, thus, is initiated in the haploid pronuclei shortly after fertilization and prior to fusion. The major portion of DNA synthesis, as evidenced by thymidine uptake, appears to be during a 20 to 30 minute period after fertilization. Fertilization is associated with the activation of a mechanism which initiates early and independent replication of DNA in both the male and female pronuclei. PMID:19866590

  2. Ganciclovir uptake in human mammary carcinoma cells expressing herpes simplex virus thymidine kinase

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    Haberkorn, Uwe; Khazaie, Khashayarsha; Morr, Iris; Altmann, Annette; Mueller, Markus; Kaick, Gerhard van

    1998-05-01

    Assessment of suicide enzyme activity would have considerable impact on the planning and the individualization of suicide gene therapy of malignant tumors. This may be done by determining the pharmacokinetics of specific substrates. We generated ganciclovir (GCV)-sensitive human mammary carcinoma cell lines after transfection with a retroviral vector bearing the herpes simplex virus thymidine kinase (HSV-tk) gene. Thereafter, uptake measurements and HPLC analyses were performed up to 48 h in an HSV-tk-expressing cell line and in a wild-type cell line using tritiated GCV. HSV-tk-expressing cells showed higher GCV uptake and phosphorylation than control cells, whereas in wild-type MCF7 cells no phosphorylated GCV was detected. In bystander experiments the total GCV uptake was related to the amount of HSV-tk-expressing cells. Furthermore, the uptake of GCV correlated closely with the growth inhibition (r=0.92). Therefore, the accumulation of specific substrates may serve as an indicator of the HSV-tk activity and of therapy outcome. Inhibition and competition experiments demonstrated slow transport of GCV by the nucleoside carriers. The slow uptake and low affinity to HSV-tk indicate that GCV is not an ideal substrate for the nucleoside transport systems or for HSV-tk. This may be the limiting factor for therapy success, necessitating the search for better substrates of HSV-tk.

  3. Cytoenzymology and 3H-thymidine uptake of retro-ocular connective tissue cultures in experimental endocrino-exophthalmos.

    Science.gov (United States)

    Vaida, E; Petrescu, R; Ghinea, E; Stefaneanu, L

    1976-01-01

    The in vitro retro-ocular connective tissue cultures from guinea pigs with endocrine exophthalmos were studied before and after retro-ocular treatment with cortisol and hyaluronidase. Both cortisol and hyaluronidase inhibited the cell proliferation, the cytoenzymic activities of oxydoreductases, the 3H-thymidine uptake, the number of mitoses and the protein content of cultivated cells.

  4. Influence of dehydroepiandrosterone on G-6-PD activity and /sup 3/H-thymidine uptake of human lymphocytes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ennas, M.G.; Laconi, S.; Dessi, S.; Milia, G.; Murru, M.R.; Manconi, P.E.

    1987-01-01

    Dehydroepiandrosterone (DHEA) was found to inhibit experimental cancer development in mouse and rat lung, colon and mammary gland. Since DHEA is a potent inhibitor of mammalian G-6-PD, the hypothesis that the compound could inhibit cell proliferation through an inhibition of the pentose phosphate pathway has been formulated. We studied the effects of DHEA on the proliferation in vitro of human lymphocytes induced by several mitogens (PHA, ConA and PWM), measuring /sup 3/H-thymidine uptake. DHEA inhibited /sup 3/H-thymidine uptake of mitogen-stimulated cells from both G-6-PD+ and G-6-PD- (mediterranean type deficiency) individuals in a dose-dependent and reversible fashion. The inhibitory effect was found even if DHEA was added to cells in the last hours of culture, simultaneously with the addition of /sup 3/H-thymidine. These data suggest that the inhibition of thymidine uptake induced by DHEA on human lymphocytes probably does not depend on the inhibition of G-6-PD.

  5. Elevation of radiolabelled thymidine uptake in RIF-1 fibrosarcoma and HT29 colon adenocarcinoma cells after treatment with thymidylate synthase inhibitors

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    Yau, Kawai; Price, Patricia; Pillai, Radhakrishma G.; Aboagye, Eric [Imperial College, Imaging Sciences, London (United Kingdom)

    2006-09-15

    We recently showed an increase in tumour uptake of 2-[{sup 11}C]thymidine in patients with gastrointestinal malignancies after thymidylate synthase (TS) inhibition. To understand the phenomenon in more detail, we investigated whether TS inhibition by different TS inhibitors leads to a dose- and time-dependent change in the uptake of radiolabelled thymidine, and whether radiotracer uptake is related to changes in cell viability resulting from treatment. RIF-1 and HT29 cells were treated with the TS inhibitors 5-fluorouracil (5-FU) and AG337 (nolatrexed dihydrochloride), as well as cisplatin as control. The cell viability and net accumulation of [{sup 3}H]thymidine after a 1-h pulse was determined at different times after drug treatment. In both cell lines, [{sup 3}H]thymidine uptake increased after a 2-h treatment with 5-FU, in a dose- and time-dependent manner. [{sup 3}H]thymidine uptake decreased at 24 and 48 h post treatment. AG337 also produced a similar effect. In contrast to the TS inhibitors, cisplatin decreased [{sup 3}H]thymidine uptake in RIF-1 and HT29 cells at all time points. Cell viability was compromised only after 24 h. Using two types of TS inhibitor, we have shown an increase in [{sup 3}H]thymidine uptake, in a dose-dependent manner, a few hours after TS inhibition when the cell viability was not compromised. This effect was not seen with a non-TS inhibitor. These findings suggest that 2-[{sup 11}C]thymidine positron emission tomography can be used to study TS inhibition in vivo at early time points when cell viability is not compromised and may therefore be helpful in the development of new TS inhibitors and in differentiating between patients with tumours sensitive to TS inhibitors and those unlikely to respond. (orig.)

  6. Effect of p53 activation on cell growth, thymidine kinase-1 activity, and 3'-deoxy-3'fluorothymidine uptake

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Jeffrey L. E-mail: jschwart@u.washington.edu; Tamura, Yasuko; Jordan, Robert; Grierson, John R.; Krohn, Kenneth A

    2004-05-01

    The use of thymidine (TdR) and thymidine analogs such as 3'-deoxy-3'-fluorothymidine (FLT) as positron emission tomography (PET)-based tracers of tumor proliferation rate is based on the hypothesis that measurement of uptake of these nucleosides, a function primarily of thymidine kinase-1 (TK{sub 1}) activity, provides an accurate measure of cell proliferation in tumors. Tumor growth is influenced by many factors including the oxygen concentration within tumors and whether tumor cells have been exposed to cytotoxic therapies. The p53 gene plays an important role in regulating growth under both of these conditions. The goal of this study was to investigate the influence of p53 activation on cell growth, TK{sub 1} activity, and FLT uptake. To accomplish this, TK{sub 1} activity, S phase fraction, and the uptake of FLT were determined in plateau-phase and exponentially growing cultures of an isogenic pair of human tumor cell lines in which p53 expression was normal or inactivated by human papilloma virus type 16 E6 expression. Ionizing radiation exposure was used to stimulate p53 activity and to induce alterations in cell cycle progression. We found that exposure of cells to ionizing radiation induced dose-dependent changes in cell cycle progression in both cell lines. The relationship between S phase percentage, TK{sub 1} activity, and FLT uptake were essentially unchanged in the p53-normal cell line. In contrast, TK{sub 1} activity and FLT uptake remained high in the p53-deficient variant even when S phase percentage was low due to a p53-dependent G2 arrest. We conclude that a functional p53 response is required to maintain the normal relationship between TK1 activity and S phase percentage following radiation exposure.

  7. Correlations of {sup 18}F-fluorothymidine uptake with pathological tumour size, Ki-67 and thymidine kinase 1 expressions in primary and metastatic lymph node colorectal cancer foci

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    Nakajo, Masatoyo; Nakajo, Masayuki [Kagoshima University, Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima (Japan); Nanpuh Hospital, Department of Radiology, Kagoshima (Japan); Kajiya, Yoriko; Tani, Atsushi [Nanpuh Hospital, Department of Radiology, Kagoshima (Japan); Goto, Yuko; Higashi, Michiyo [Kagoshima University, Department of Human Pathology, Graduate School of Medical and Dental Sciences, Kagoshima, 890-8544 (Japan); Jinguji, Megumi; Fukukura, Yoshihiko [Kagoshima University, Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima (Japan); Tanaka, Sadao [Nanpuh Hospital, Department of Pathology, Kagoshima (Japan)

    2014-12-15

    To examine correlations of {sup 18}F-fluorothymidine (FLT) uptake with pathological tumour size and immunohistochemical Ki-67, and thymidine kinase 1 (TK-1) expressions in primary and metastatic node colorectal cancer foci. Thirty primary cancers (PCs) and 37 metastatic nodes (MNs) were included. FLT uptake was assessed by visual scores (non-visible: 0-1 and visible: 2-4), standardized uptake value (SUV), and correlated with size, Ki-67, and TK-1. SUV was measured in visible lesions. FLT heterogeneity was assessed by visual scores (no heterogeneous uptake: 0 and heterogeneous uptake: 1-4). Forty-two lesions were visible. The visible group showed significantly higher values than the non-visible group in size, Ki-67, and TK-1 (each p < 0.05). Size correlated significantly with visual score (PC; ρ = 0.74 and MN; ρ = 0.63), SUVmax (PC; ρ = 0.49, and MN; ρ = 0.76), and SUVmean (PC; ρ = 0.40 and MN; ρ = 0.76) (each p < 0.05). Visual score correlated significantly with size (ρ = 0.86), Ki-67max (ρ = 0.35), Ki-67mean (ρ = 0.38), TK-1max (ρ = 0.35) and TK-1mean (ρ = 0.25) (each p < 0.05). No significant correlations were found between FLT uptake and Ki-67 or TK-1 in 42 visible lesions (each p > 0.05). Heterogeneous FLT uptake was noted in 73 % (22/30) of PCs. FLT uptake correlated with size. Heterogeneous FLT distribution in colorectal cancers may be one of the causes of weak or lack of FLT uptake/Ki-67 or TK-1 correlation. (orig.)

  8. Cytotoxicity and cellular uptake of pyrimidine nucleosides for imaging herpes simplex type-1 thymidine kinase (HSV-1 TK) expression in mammalian cells

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    Morin, Kevin W.; Duan Weili; Xu Lihua; Zhou Aihua; Moharram, Sameh; Knaus, Edward E.; McEwan, Alexander J.B.; Wiebe, Leonard I. E-mail: leonard.wiebe@ualberta.ca

    2004-07-01

    In vivo transfer of the herpes simplex virus type-1 thymidine kinase (HSV-1 TK) gene, with subsequent administration of antiviral drugs such as ganciclovir, has emerged as a promising gene therapy protocol for treating proliferative disorders. The in vitro cytotoxicities (IC{sub 50}) for two series of 5-iodo- and (E)-5-(2-iodovinyl)-substituted 2'-deoxy- and 2'-deoxy-2'-fluoro-pyrimidine nucleosides ranged from millimolar to low nanomolar concentrations in mammalian tumor cell lines (KBALB; R-970-5; 143B; EMT-6) and their counterparts engineered to express HSV-1 TK (KBALB-STK; 143B-LTK). Their HSV-1 TK selectivity indices ranged from one (nonselective) to one million (highly selective) based on cytotoxicity, with FIRU being the least toxic to all cell lines, and FIAU being most toxic. HSV-1 TK selectivity, based on uptake, ranged from 10 to 140, with IVDU being most selective for HSV-1 TK expressing cells, followed by IVFRU, FIRU, FIAU, IVFAU and finally IUDR. Phosphorylation of [{sup 125}I]FIAU led to incorporation of the radiolabel into nucleic acids, whereas IVFRU and FIRU radioactivity was trapped primarily in the nucleotide pool. These data indicate that cytotoxicity does not depend on initial metabolic trapping (e.g., phosphorylation), but on elaboration of the mononucleotides to more cytotoxic anabolites. Lipophilicities and nucleoside transport rates of the six nucleosides tested were within narrow ranges. This supports the premise that cellular biochemistry, and not cellular bioavailability, is responsible for the observed broad range of cytotoxicity and trapping. In vivo biodistribution studies with 5-[{sup 125}I]iodo-2'-fluoro-2'-deoxyribouridine (FIRU), 5-[{sup 125}I]iodo-2'-fluoro-2'-deoxyarabinouridine (FIAU) and (E)-5-(2-[{sup 125}I]iodovinyl)-2'-fluoro-2'-deoxyuridine (IVFRU) demonstrate selective accumulation of all three radiotracers in HSV-1 TK-expressing KBABK-STK tumors, compared to their very low

  9. Trichoderma -mediated enhancement of nutrient uptake and ...

    African Journals Online (AJOL)

    Trichoderma harzianum is a naturally occurring filamentous fungus which solubilizes mineral nutrients and inorganic fertilizers, increasing availability and uptake of nutrients to the plant. Rhizoctonia solani is a major problem for seedlings, causing damping-off and in mature plants causing foot and root rot in the tomato crop, ...

  10. Organic acids enhance the uptake of lead by wheat roots.

    Science.gov (United States)

    Wang, Huanhua; Shan, Xiaoquan; Liu, Tao; Xie, Yaning; Wen, Bei; Zhang, Shuzhen; Han, Fang; van Genuchten, Martinus Th

    2007-05-01

    The uptake and bioavailability of lead (Pb) in soil-plant systems remain poorly understood. This study indicates that acetic and malic acids enhance the uptake of Pb by wheat (Triticum aestivum L.) roots under hydroponic conditions. The net concentration-dependent uptake influx of Pb in the presence and absence of organic acids was characterized by Michaelis-Menten type nonsaturating kinetic curves that could be resolved into linear and saturable components. Fitted maximum uptake rates (V (max)) of the Michaelis-Menton saturable component in the presence of acetic and malic acids were, respectively, 2.45 and 1.63 times those of the control, while the Michaelis-Menten K (m) values of 5.5, 3.7 and 2.2 microM, respectively, remained unchanged. Enhanced Pb uptake by organic acids was partially mediated by Ca(2+) and K(+) channels, and also depended upon the physiological function of the plasma membrane P-type ATPase. Uptake may have been further enhanced by an effectively thinner unstirred layer of Pb adjacent to the roots, leading to more rapid diffusion towards roots. X-ray absorption spectroscopic studies provided evidence that the coordination environment of Pb in wheat roots was similar to that of Pb(CH(3)COO)(2)x3H(2)O in that one Pb atom was coordinated to four oxygen atoms via the carboxylate group.

  11. Tanshinone IIA increases the bystander effect of herpes simplex virus thymidine kinase/ganciclovir gene therapy via enhanced gap junctional intercellular communication.

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    Jianyong Xiao

    Full Text Available The bystander effect is an intriguing phenomenon by which adjacent cells become sensitized to drug treatment during gene therapy with herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV. This effect is reported to be mediated by gap junctional intercellular communication (GJIC, and therefore, we postulated that upregulation of genes that facilitate GJIC may enhance the HSV-tk/GCV bystander effect. Previous findings have shown Tanshinone IIA (Tan IIA, a chemical substance derived from a Chinese medicine herb, promotes the upregulation of the connexins Cx26 and Cx43 in B16 cells. Because gap junctions are formed by connexins, we hypothesized that Tan IIA might increase GJIC. Our results show that Tan IIA increased GJIC in B16 melanoma cells, leading to more efficient GCV-induced bystander killing in cells stably expressing HSV-tk. Additionally, in vivo experiments demonstrated that tumors in mice with 10% HSV-tk positive B16 cells and 90% wild-type B16 cells became smaller following treatment with the combination of GCV and Tan IIA as compared to GCV or Tan IIA alone. These data demonstrate that Tan IIA can augment the bystander effect of HSV-tk/GCV system through increased gap junction coupling, which adds strength to the promising strategy that develops connexins inducer to potentiate the effects of suicide gene therapy.

  12. Vesicular Stomatitis Virus G Glycoprotein and ATRA Enhanced Bystander Killing of Chemoresistant Leukemic Cells by Herpes Simplex Virus Thymidine Kinase/Ganciclovir.

    Science.gov (United States)

    Hu, Chenxi; Chen, Zheng; Zhao, Wenjun; Wei, Lirong; Zheng, Yanwen; He, Chao; Zeng, Yan; Yin, Bin

    2014-02-01

    Refractoriness of acute myeloid leukemia (AML) cells to chemotherapeutics represents a major clinical barrier. Suicide gene therapy for cancer has been attractive but with limited clinical efficacy. In this study, we investigated the potential application of herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) based system to inhibit chemoresistant AML cells. We first generated Ara-C resistant K562 cells and doxorubicin-resistant THP-1 cells. We found that the HSV-TK/GCV anticancer system suppressed drug resistant leukemic cells in culture. Chemoresistant AML cell lines displayed similar sensitivity to HSV-TK/GCV. Moreover, HSV-TK/GCV killing of leukemic cells was augmented to a mild but significant extent by all-trans retinoic acid (ATRA) with concomitant upregulation of Connexin 43, a major component of gap junctions. Interestingly, HSV-TK/GCV killing was enhanced by expression of vesicular stomatitis virus G glycoprotein (VSV-G), a fusogenic membrane protein, which also increased leukemic cell fusion. Co-culture resistant cells expressing HSV-TK and cells stably transduced with VSV-G showed that expression of VSV-G could promote the bystander killing effect of HSV-TK/GCV. Furthermore, combination of HSV-TK/GCV with VSV-G plus ATRA produced more pronounced antileukemia effect. These results suggest that the HSV-TK/GCV system in combination with fusogenic membrane proteins and/or ATRA could provide a strategy to mitigate the chemoresistance of AML.

  13. Tanshinone IIA increases the bystander effect of herpes simplex virus thymidine kinase/ganciclovir gene therapy via enhanced gap junctional intercellular communication.

    Science.gov (United States)

    Xiao, Jianyong; Zhang, Guangxian; Qiu, Pengxiang; Liu, Xijuan; Wu, Yingya; Du, Biaoyan; Li, Jiefen; Zhou, Jing; Li, Jingjing; Tan, Yuhui

    2013-01-01

    The bystander effect is an intriguing phenomenon by which adjacent cells become sensitized to drug treatment during gene therapy with herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV). This effect is reported to be mediated by gap junctional intercellular communication (GJIC), and therefore, we postulated that upregulation of genes that facilitate GJIC may enhance the HSV-tk/GCV bystander effect. Previous findings have shown Tanshinone IIA (Tan IIA), a chemical substance derived from a Chinese medicine herb, promotes the upregulation of the connexins Cx26 and Cx43 in B16 cells. Because gap junctions are formed by connexins, we hypothesized that Tan IIA might increase GJIC. Our results show that Tan IIA increased GJIC in B16 melanoma cells, leading to more efficient GCV-induced bystander killing in cells stably expressing HSV-tk. Additionally, in vivo experiments demonstrated that tumors in mice with 10% HSV-tk positive B16 cells and 90% wild-type B16 cells became smaller following treatment with the combination of GCV and Tan IIA as compared to GCV or Tan IIA alone. These data demonstrate that Tan IIA can augment the bystander effect of HSV-tk/GCV system through increased gap junction coupling, which adds strength to the promising strategy that develops connexins inducer to potentiate the effects of suicide gene therapy.

  14. Farmer Field Schools as a Springboard for Enhanced Uptake of ...

    African Journals Online (AJOL)

    The latest approach in enhancing the uptake of agricultural technologies is through the Farmer Field Schools that have only a short history in Tanzania.This paper reviews the literature on Farmer Field Schools, first giving a brief description of the nature of Farmer Field Schools. This is then followed by experiences from ...

  15. Thymidine selectively enhances growth suppressive effects of camptothecin/irinotecan in MSI+ cells and tumors containing a mutation of MRE11

    DEFF Research Database (Denmark)

    Rodriguez, Rene; Hansen, Lasse Tengbjerg; Phear, Geraldine

    2008-01-01

    -thymidine combinations by measuring colony formation, cell cycle distribution, and senescence. Cell strains defective in p53, p21, or Mre11 were used in these assays to investigate the role of these cell cycle regulators. The in vivo antitumor response of xenografts to irinotecan and thymidine combinations was assessed...... in nude mice. RESULTS: Camptothecin-thymidine combinations suppress colony formation of MMR-deficient tumor cells 10- to 3,000-fold relative to that obtained with camptothecin alone and significantly reduce the concentrations of the agents required to induce late S/G(2) arrest and senescence. Sensitivity......PURPOSE: DNA synthesis inhibitors and damaging agents are widely used in cancer therapy; however, sensitivity of tumors to such agents is highly variable. The response of tumor cells in culture to these agents is strongly influenced by the status of DNA damage response pathways. Here, we attempt...

  16. Enhanced oleate uptake and lipotoxicity associated with laurate.

    Science.gov (United States)

    Kitaura, Yasuyuki; Inoue, Kana; Kato, Naoki; Matsushita, Nahomi; Shimomura, Yoshiharu

    2015-01-01

    Free fatty acids have been reported to induce cell death (lipotoxicity), but the effects depend on the carbon chain length and number of double bonds. Medium-chain saturated fatty acids (MC-SFAs), such as laurate, have less lipotoxicity than long-chain saturated fatty acids (LC-SFAs), such as palmitate. Monounsaturated fatty acids, such as oleate, have also been reported not only to exert cytotoxic effects, but also to reduce the lipotoxicity of LC-SFA. However the interaction between MC-SFA and oleate with respect to cell death is unclear. In this report, we found that lipotoxicity was enhanced by a combination of laurate and oleate relative to either fatty acid alone. The possible mechanisms involved were examined by measuring the production of reactive oxygen species, mitochondrial depolarization, caspase-3 activity, and lipid droplet formation. Although the stress signals and cell death pathways were distinct among different cell types, we found a common phenomenon of enhanced lipid droplet formation in all cells tested. Using fluorescent- or radioisotope-labeled fatty acids, we found that oleate, but not laurate, increased the uptake of fluorescent-labeled fatty acids, and the combinatory effect was more efficient than with oleate alone. We also found that laurate increased oleate uptake, but the effect of oleate on laurate uptake varied among cell types. These results suggest that laurate enhances the influx rate of oleate, the increased intracellular concentration of which not only enhances lipid storage, but also induces cell death by lipotoxic stress responses, which vary according to cell type.

  17. Glucose transport and apoptosis after gene therapy with HSV thymidine kinase

    Energy Technology Data Exchange (ETDEWEB)

    Haberkorn, U.; Henze, M. [Heidelberg Univ. (Germany). Abt. fuer Klinische Nuklearmedizin; Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Altmann, A.; Morr, I.; Jiang Shiming [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Kamencic, H.; Traut, U.; Metz, J.; Kinscherf, R. [Dept. of Anatomy and Cell Biology III, Univ. of Heidelberg (Germany)

    2001-11-01

    The relation between tumour metabolism and induction of apoptosis by gene therapy was investigated in a rat Morris hepatoma (MH3924A) model expressing the HSV thymidine kinase (HSVtk) gene. In vivo the amount of glucose transporter (GLUT1 and GLUT3 isoforms) expressing cells was determined in tumours of untreated and treated animals using immunohistochemistry. In vitro uptake studies with 2-fluoro-2-deoxy-D-glucose (FDG), 3-O-methylglucose and thymidine (TdR) and a TUNEL (TdT-mediated dUTP nick end labelling) assay for the assessment of apoptosis were done immediately and 24 h after treatment of the recombinant cells with different doses of ganciclovir (GCV). Immunohistochemistry revealed a significant increase in GLUT1 in treated tumours which showed enhanced transport activity for FDG. In vitro the FDG and 3-O-methylglucose uptake increased to 186% when compared with that of the non-treated cells immediately after incubation with GCV. However, 24 h later the FDG uptake had declined to its normal level, whereas the accumulation of 3-O-methylglucose remained elevated. The uptake of TdR, which was determined simultaneously, decreased in the acid-insoluble fraction of the cells to 27% and 11%, respectively, immediately and 24 h after therapy, while in the acid-soluble fraction it increased to 229% and to 167%, respectively. Employing the TUNEL technique, 25% of cells were found to be apoptotic 24 h after the termination of GCV treatment. Inhibition of glucose transport by cytochalasin B or competition with deoxyglucose resulted in a 78% (cytochalasin B) and 88% (deoxyglucose) decrease in FDG uptake in the recombinant hepatoma cells and in an increase in the apoptotic cell fraction. It is concluded that inhibition of enhanced glucose transport in GCV-treated cells increased apoptosis. Therefore, enhanced glucose transport seems to represent a stress reaction of tumour cells dedicated for the prevention of cell death. (orig.)

  18. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  19. γ-Oryzanol Enhances Adipocyte Differentiation and Glucose Uptake

    Directory of Open Access Journals (Sweden)

    Chang Hwa Jung

    2015-06-01

    Full Text Available Recent studies show that brown rice improves glucose intolerance and potentially the risk of diabetes, although the underlying molecular mechanisms remain unclear. One of the phytochemicals found in high concentration in brown rice is γ-oryzanol (Orz, a group of ferulic acid esters of phytosterols and triterpene alcohols. Here, we found that Orz stimulated differentiation of 3T3-L1 preadipocytes and increased the protein expression of adipogenic marker genes such as peroxisome proliferator-activated receptor gamma (PPAR-γ and CCAAT/enhanced binding protein alpha (C/EBPα. Moreover, Orz significantly increased the glucose uptake in insulin-resistant cells and translocation of glucose transporter type 4 (GLUT4 from the cytosol to the cell surface. To investigate the mechanism by which Orz stimulated cell differentiation, we examined its effects on cellular signaling of the mammalian target of rapamycin complex 1 (mTORC1, a central mediator of cellular growth and proliferation. The Orz treatment increased mTORC1 kinase activity based on phosphorylation of 70-kDa ribosomal S6 kinase 1 (S6K1. The effect of Orz on adipocyte differentiation was dependent on mTORC1 activity because rapamycin blocks cell differentiation in Orz-treated cells. Collectively, our results indicate that Orz stimulates adipocyte differentiation, enhances glucose uptake, and may be associated with cellular signaling mediated by PPAR-γ and mTORC1.

  20. Plant growth regulators enhance gold uptake in Brassica juncea.

    Science.gov (United States)

    Kulkarni, Manoj G; Stirk, Wendy A; Southway, Colin; Papenfus, Heino B; Swart, Pierre A; Lux, Alexander; Vaculík, Marek; Martinka, Michal; Van Staden, Johannes

    2013-01-01

    The use of plant growth regulators is well established and they are used in many fields of plant science for enhancing growth. Brassica juncea plants were treated with 2.5, 5.0 and 7.5 microM auxin indole-3-butyric acid (IBA), which promotes rooting. The IBA-treated plants were also sprayed with 100 microM gibberellic acid (GA3) and kinetin (Kin) to increase leaf-foliage. Gold (I) chloride (AuCl) was added to the growth medium of plants to achieve required gold concentration. The solubilizing agent ammonium thiocyanate (1 g kg(-1)) (commonly used in mining industries to solubilize gold) was added to the nutrient solution after six weeks of growth and, two weeks later, plants were harvested. Plant growth regulators improved shoot and root dry biomass of B. juncea plants. Inductively Coupled Plasma Optical Emission Spectrometry analysis showed the highest Au uptake for plants treated with 5.0 microM IBA. The average recovery of Au with this treatment was significantly greater than the control treatment by 45.8 mg kg(-1) (155.7%). The other IBA concentrations (2.5 and 7.5 microM) also showed a significant increase in Au uptake compared to the control plants by 14.7 mg kg(-1) (50%) and 42.5 mg kg(-1) (144.5%) respectively. A similar trend of Au accumulation was recorded in the roots of B. juncea plants. This study conducted in solution culture suggests that plant growth regulators can play a significant role in improving phytoextraction of Au.

  1. Accumulation of thymidine-derived sugars in thymidine phosphorylase overexpressing cells

    NARCIS (Netherlands)

    Bijnsdorp, I. V.; Azijli, K.; Jansen, E. E.; Wamelink, M. M.; Jakobs, C.; Struys, E. A.; Fukushima, M.; Kruyt, F. A. E.; Peters, G. J.

    2010-01-01

    Thymidine phosphorylase (TP) is often overexpressed in cancer and potentially plays a role in the stimulation of angiogenesis The exact mechanism of angiogenesis induction is unclear, but is postulated to be related to thymidine-derived sugars. TP catalyzes the conversion of thymidine (TdR) to

  2. Compost amendment, enhanced nutrient uptake and dry matter ...

    African Journals Online (AJOL)

    Contamination of agricultural lands with heavy metals from industrial activities reduces crop production as a result of poor soil fertility and phytotoxicity. Field trial was conducted to assess the influence of Compost and inorganic fertilizer as well as plant growth stage on growth, nutrient uptake, dry matter accumulation and ...

  3. Drivers to Enhance ICT Uptake in IBS Management Processes in the Construction Industry

    Directory of Open Access Journals (Sweden)

    Soon Ern Peniel Ang

    2016-01-01

    Full Text Available In Malaysia, as a result of the government’s initiative and future outlook in advancing the use of innovative technologies, the Industrialised Building System (IBS approach is actively promoted through several strategies and incentives as an alternative to conventional building methods. Extensive uptakes of modern Information Communication Technology (ICT applications are able to support the different IBS processes for effective production. However, it is argued that ICT uptake at the organisational level is still in its infancy. This raises the importance to identify critical drivers for effective uptake of ICT in the IBS production management process. Critical drivers to ICT uptake were identified through questionnaire survey with industry stakeholders which was analysed using mean index and critical t-value with the use of SPSS software. The top ten priority ranked drivers reflect the People, Technology and Policy elements to ICT uptake. These identified critical drivers are able enhance ICT uptake in IBS management process in the construction industry.

  4. Triterpenoids Isolated from Ziziphus jujuba Enhance Glucose Uptake Activity in Skeletal Muscle Cells.

    Science.gov (United States)

    Kawabata, Kyuichi; Kitamura, Kenji; Irie, Kazuhiro; Naruse, Shoma; Matsuura, Tomohiro; Uemae, Tomoyuki; Taira, Shu; Ohigashi, Hajime; Murakami, Shigeru; Takahashi, Masakazu; Kaido, Yoko; Kawakami, Bunsei

    2017-01-01

    Jujube (Ziziphus jujuba Mill.), a traditional folk medicine and functional food in China and South Korea, is known for its beneficial properties, which include anti-cancer, anti-oxidative, and anti-obesity effects. To assess the anti-hyperglycemic effect of jujube in this study, we investigated the glucose uptake-promoting activity of jujube in rat L6 myotubes. After determining that the jujube extract induces muscle glucose uptake, we identified the following active compounds by bioassay-guided fractionation: betulonic acid, betulinic acid, and oleanonic acid. Ursonic acid, known to be present in jujube, was semi-synthesized from ursolic acid and also observed to enhance glucose uptake. These four triterpenic acids induced glucose uptake in a glucose transporter 4-dependent manner. Comparison experiments of jujube fruits from three countries, namely, China, South Korea, and Japan, revealed that Japanese jujube has a higher content of active triterpenoids and is the most potent enhancer of glucose uptake.

  5. Transcriptional profiling of thymidine-producing strain recombineered from Escherichia coli BL21

    Directory of Open Access Journals (Sweden)

    Jin-Sook Kim

    2015-12-01

    Full Text Available DNA microarrays were used to compare the expression profiles of a thymidine overproducing strain (BLT013 and its isogenic parent, Escherichia coli BL21(DE3, when each was grown under well-defined thymidine production conditions with glycerol as carbon source. Here we describe the experimental procedures and methods in detail to reproduce the results and provide resource to be applied to similar engineering approach (available at Gene Expression Omnibus database under GSE69963. Taken together, the microarray data provide a basis for new testable hypotheses regarding enhancement of thymidine productivity and attaining a more complete understanding of nucleotide metabolism in bacteria.

  6. Enhanced Cellular Uptake of Bowl-like Microcapsules.

    Science.gov (United States)

    Li, Huiying; Zhang, Wenbo; Tong, Weijun; Gao, Changyou

    2016-05-11

    Among several properties of colloidal particles, shape is emerging as an important parameter for tailoring the interactions between particles and cells. In this study, bowl-like multilayer microcapsules were prepared by osmotic-induced invagination of their spherical counterparts in a concentrated polyelectrolyte solution. The internalization behaviors of bowl-like and spherical microcapsules were compared by coincubation with smooth muscle cells (SMCs) and macrophages. The bowl-like capsules tended to attach onto the cell membranes from the bend side and could be enwrapped by the membranes of SMCs, leading to a faster uptake rate and larger accumulation inside cells than those of their spherical counterparts. These results are important for understanding the shape-dependent internalization behavior, providing useful guidance for further materials design especially in biomedical applications.

  7. Ability of higenamine and related compounds to enhance glucose uptake in L6 cells.

    Science.gov (United States)

    Kato, Eisuke; Kimura, Shunsuke; Kawabata, Jun

    2017-12-15

    β2-Adrenergic receptor (β2AR) agonists are employed as bronchodilators to treat pulmonary disorders, but are attracting attention for their modulation of glucose handling and energy expenditure. Higenamine is a tetrahydroisoquinoline present in several plant species and has β2AR agonist activity, but the involvement of each functional groups in β2AR agonist activity and its effectiveness compared with endogenous catecholamines (dopamine, epinephrine, and norepinephrine) has rarely been studied. Glucose uptake of muscle cells are known to be induced through β2AR activation. Here, the ability to enhance glucose uptake of higenamine was compared with that of several methylated derivatives of higenamine or endogenous catecholamines. We found that: (i) the functional groups of higenamine except for the 4'-hydroxy group are required to enhance glucose uptake; (ii) higenamine shows a comparable ability to enhance glucose uptake with that of epinephrine and norepinephrine; (iii) the S-isomer shows a greater ability to enhance glucose uptake compared with that of the R-isomer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Enhancement of the relative uptake of {sup 18}F-FDG in mouse fibrosarcoma by rolipram

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Kaoru; Hosoi, Rie; Momosaki, Sotaro; Inoue, Osamu [Osaka Univ., Suita (Japan). School of Allied Health Science; Koike, Sachiko; Ando, Koichi [National Inst. of Radiological Sciences, Chiba (Japan); Nishimura, Tsunehiko [Kyoto Prefectural Univ. of Medicine (Japan)

    2002-11-01

    The effect of rolipram, a selective phosphodiesterase type 4 inhibitor, on the uptake of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in tumor tissue was examined in mice transplanted with NFSa fibrosarcoma. The uptake indexes of {sup 18}F-FDG in the heart, skeletal muscle and brain remarkably decreased after treatment with 3 mg/kg of rolipram (heart: 13%, skeletal muscle: 14%, brain: 31%), but fibrosarcoma tissue showed only a 50% reduction in the uptake index of {sup 18}F-FDG. The tumor/muscle ratio of radioactivity 30 min after {sup 18}F-FDG injection was consequently enhanced from 1.9 to 6.5 by rolipram. This indicates the possible use of rolipram to enhance the sensitivity of tumor detection, as well as characterization of tumors in {sup 18}F-FDG PET. (author)

  9. HIV screening at health facilities and community pharmacies in Kenya : Enhancing test uptake and early diagnosis

    NARCIS (Netherlands)

    Mugo, P.M.

    2017-01-01

    Despite a tremendous scale-up of antiretroviral therapy, as many as 54% of HIV-infected persons globally remain undiagnosed hence are not on treatment. This thesis presents findings from a series of studies conducted in Coastal Kenya aiming to enhance HIV test uptake and early diagnosis. We found

  10. Selective chemical binding enhances cesium tolerance in plants through inhibition of cesium uptake

    DEFF Research Database (Denmark)

    Adams, Eri; Chaban, Vitaly; Khandelia, Himanshu

    2015-01-01

    High concentrations of cesium (Cs(+)) inhibit plant growth but the detailed mechanisms of Cs(+) uptake, transport and response in plants are not well known. In order to identify small molecules with a capacity to enhance plant tolerance to Cs(+), chemical library screening was performed using Ara...

  11. Enzymatic Regulation of Cytosolic Thymidine Kinase 1 and Mitochondrial Thymidine Kinase 2

    DEFF Research Database (Denmark)

    Munch-Petersen, Birgitte

    2010-01-01

    . Apart from the complex de novo synthesis of dTTP through UDP reduction, dTTP is provided through salvage of thymidine catalyzed by the thymidine kinases, the cytosolic and cell cycle regulated TK1 and the mitochondrial and constitutively expressed TK2. The complex enzymatic regulation of TK1 and TK2...

  12. Warming enhances nitrogen uptake by winter wheat under two tillage systems

    Science.gov (United States)

    Hou, Ruixing

    2017-04-01

    Despite the perceived importance of N to wheat growth and production, few studies have attempted to examine the effects of warming on wheat N uptake patter or its preference for NO3-N, NH4+-N, especially under different tillage systems. In the North China Plain, an in situ 15N labelling study was conducted on winter wheat in which effects of experimental warming during the jointing stage under till and no-till tillage systems on uptake of total N and three forms of N (NO3-N, NH4+-N and glycine-N) was studied. Warming strongly enhanced wheat biomass and N content in both roots and shoots. Total N uptake rates increased by 40% and 47% under till and no-till treatments, respectively. Warming changed the uptake pattern of the three forms of N by significantly increasing the contributions of NO3-N and glycine-derived N, while decreasing the contribution of NH4+-N. Between the two tillage systems, wheat under no-till without warming obtained more N than till. However, warming was found to suppress N uptake under no-till relative to till. Collectively, high temperatures accelerate N sequestration in winter wheat and improve the preferential contribution of NO3-N due to high soil N availability and enhanced microbial activity.

  13. Do anthropogenic aerosols enhance CO2 uptake by plants?

    Science.gov (United States)

    Strada, S.; Unger, N.

    2013-12-01

    Plant productivity (photosynthesis) is tightly connected to the supply of solar radiation and water and to surface temperature. Solar radiation reaching the Earth's surface and the water cycle are strongly modified by anthropogenic aerosols. Aerosols reduce the amount of global radiation and surface temperature, and they modify the partitioning between direct and diffuse radiation. Moreover, they modify cloud radiative properties and lifetime. These aerosols effects may influence Gross Primary Productivity (GPP): (1) by intensifying the diffuse-radiation fertilization effect (i.e. plant productivity is more efficient under diffuse light whose amount may increase due to aerosol loading); (2) by modifying water supply through suppression/enhancement of rainfall; (3) by reducing surface temperature. Among aerosol impacts on GPP, it is unclear if there exists a prevailing one, or if the prevailing impact varies across ecosystems. Feedbacks to GPP from the effects of biogenic secondary organic aerosol (BSOA) formed from vegetation reactive carbon emissions have not been investigated. Moreover, human-made pollution and biomass burning induce high ozone concentrations that simultaneously reduce plant productivity. We apply satellite observations and global model simulations to investigate the spatial pattern in the relationship between aerosols and plant productivity across different ecosystems, and whether plants control their diffuse radiation environment through the reactive carbon emissions. We quantify the correlation between MODIS GPP and: (1) fine-fraction Aerosol Optical Depth from MODIS (fAOD); (2) ozone levels in the middle troposphere from TES. The analysis of satellite data reveals strong positive correlation between GPP and fAOD in temperate and boreal ecosystems, and strong negative correlation in tropical ecosystems. The tropical ecosystem also presents strong negative correlation between GPP and O3. Simulations using Yale-E2 global carbon

  14. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi-Ching; Chang, Fan-Yu [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Tu, Shu-Ju [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Chen, Jyh-Ping [Department of Chemical and Materials Engineering, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Ma, Yunn-Hwa, E-mail: yhma@mail.cgu.edu.tw [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Department of Neurology, Chang Gung Memorial Hospital, Guishan, Taoyuan City 33305, Taiwan, ROC (China)

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNP{sub cell}) appeared to be magnetic field- and concentration-dependent. In H-field, MNP{sub cell} reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNP{sub cell}, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNP{sub cell} in the L-field may reach as high as 80% of that in H-field during 1–6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNP{sub cell} analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo. - Graphical abstract: Averaged MNP uptake by glioma cells in the low and non-uniformed magnetic field reached as high as 80% of that in uniformed magnetic field, which is probably due to both heterogeneous distributions of MNPs in the non-uniformed magnetic field and high capacity of the MNP uptake by these cells. - Highlights:

  15. Intracellular cholesterol-binding proteins enhance HDL-mediated cholesterol uptake in cultured primary mouse hepatocytes

    Science.gov (United States)

    Storey, Stephen M.; McIntosh, Avery L.; Huang, Huan; Landrock, Kerstin K.; Martin, Gregory G.; Landrock, Danilo; Payne, H. Ross; Atshaves, Barbara P.; Kier, Ann B.

    2012-01-01

    A major gap in our knowledge of rapid hepatic HDL cholesterol clearance is the role of key intracellular factors that influence this process. Although the reverse cholesterol transport pathway targets HDL to the liver for net elimination of free cholesterol from the body, molecular details governing cholesterol uptake into hepatocytes are not completely understood. Therefore, the effects of sterol carrier protein (SCP)-2 and liver fatty acid-binding protein (L-FABP), high-affinity cholesterol-binding proteins present in hepatocyte cytosol, on HDL-mediated free cholesterol uptake were examined using gene-targeted mouse models, cultured primary hepatocytes, and 22-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol). While SCP-2 overexpression enhanced NBD-cholesterol uptake, counterintuitively, SCP-2/SCP-x gene ablation also 1) enhanced the rapid molecular phase of free sterol uptake detectable in cholesterol and 2) differentially enhanced free cholesterol uptake mediated by the HDL3, rather than the HDL2, subfraction. The increased HDL free cholesterol uptake was not due to increased expression or distribution of the HDL receptor [scavenger receptor B1 (SRB1)], proteins regulating SRB1 [postsynaptic density protein (PSD-95)/Drosophila disk large tumor suppressor (dlg)/tight junction protein (ZO1) and 17-kDa membrane-associated protein], or other intracellular cholesterol trafficking proteins (steroidogenic acute response protein D, Niemann Pick C, and oxysterol-binding protein-related proteins). However, expression of L-FABP, the single most prevalent hepatic cytosolic protein that binds cholesterol, was upregulated twofold in SCP-2/SCP-x null hepatocytes. Double-immunogold electron microscopy detected L-FABP sufficiently close to SRB1 for direct interaction, similar to SCP-2. These data suggest a role for L-FABP in HDL cholesterol uptake, a finding confirmed with SCP-2/SCP-x/L-FABP null mice and hepatocytes. Taken together

  16. Modulated synthesis of chromium-based metal-organic framework (MIL-101) with enhanced hydrogen uptake

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2014-08-01

    Full Text Available -1 International Journal of Hydrogen Energy Vol. 39(23) Modulated synthesis of chromium-based metalorganic framework (MIL-101) with enhanced hydrogen uptake Jianwei Ren a,*, Nicholas M. Musyoka a, Henrietta W. Langmi a, Tshiamo Segakweng a, Brian C. North... a, Mkhulu Mathe a, Xiangdong Kang b a HySA Infrastructure Centre of Competence, Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), PO Box 395, Pretoria 0001, South Africa b Shenyang National Laboratory...

  17. Nitrogen removal by thiosulfate-driven denitrification and plant uptake in enhanced floating treatment wetland.

    Science.gov (United States)

    Gao, Lei; Zhou, Weili; Wu, Suqing; He, Shengbing; Huang, Jungchen; Zhang, Xu

    2018-04-15

    This study investigated the potential of thiosulfate-driven autotrophic enhanced floating treatment wetland (AEFTW) in removing nitrogen from the secondary effluent at the relatively short hydraulic retention times and low S/N ratios. Simultaneous autotrophic and heterotrophic denitrification was observed in AEFTW. The peak TN removal rate (15.3gm-2d-1) exceeded most of the reported floating treatment wetlands. Based on the kinetic model results, low mean temperature coefficient and high k20 verified that the excellent performance in AEFTW diminished the microbial dependence on temperature. Nitrogen removal performance of enhanced floating treatment wetland (EFTW) and floating treatment wetland (FTW) were similar and highly sensitive to temperature. The interaction of sulfur transformation on the nitrogen, carbon uptake of plants was studied. Thiosulfate addition significantly raised sulfur content in the shoots and further enhanced the uptake of nitrogen and carbon, and increased the plant biomass at the same time. Higher composition of autotrophic and heterotrophic denitrifiers in AEFTW interpreted the occurrence of mixotrophic denitrification during summer. Thiosulfate induced mutual promotion of nitrogen removal by plant uptake and microbial denitrification in AEFTW. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Sodium-glucose transporter-2 (SGLT2; SLC5A2 enhances cellular uptake of aminoglycosides.

    Directory of Open Access Journals (Sweden)

    Meiyan Jiang

    Full Text Available Aminoglycoside antibiotics, like gentamicin, continue to be clinically essential worldwide to treat life-threatening bacterial infections. Yet, the ototoxic and nephrotoxic side-effects of these drugs remain serious complications. A major site of gentamicin uptake and toxicity resides within kidney proximal tubules that also heavily express electrogenic sodium-glucose transporter-2 (SGLT2; SLC5A2 in vivo. We hypothesized that SGLT2 traffics gentamicin, and promotes cellular toxicity. We confirmed in vitro expression of SGLT2 in proximal tubule-derived KPT2 cells, and absence in distal tubule-derived KDT3 cells. D-glucose competitively decreased the uptake of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-ylamino-2-deoxyglucose (2-NBDG, a fluorescent analog of glucose, and fluorescently-tagged gentamicin (GTTR by KPT2 cells. Phlorizin, an SGLT2 antagonist, strongly inhibited uptake of 2-NBDG and GTTR by KPT2 cells in a dose- and time-dependent manner. GTTR uptake was elevated in KDT3 cells transfected with SGLT2 (compared to controls; and this enhanced uptake was attenuated by phlorizin. Knock-down of SGLT2 expression by siRNA reduced gentamicin-induced cytotoxicity. In vivo, SGLT2 was robustly expressed in kidney proximal tubule cells of heterozygous, but not null, mice. Phlorizin decreased GTTR uptake by kidney proximal tubule cells in Sglt2+/- mice, but not in Sglt2-/- mice. However, serum GTTR levels were elevated in Sglt2-/- mice compared to Sglt2+/- mice, and in phlorizin-treated Sglt2+/- mice compared to vehicle-treated Sglt2+/- mice. Loss of SGLT2 function by antagonism or by gene deletion did not affect gentamicin cochlear loading or auditory function. Phlorizin did not protect wild-type mice from kanamycin-induced ototoxicity. We conclude that SGLT2 can traffic gentamicin and contribute to gentamicin-induced cytotoxicity.

  19. Enhanced Iron and Selenium Uptake in Plants by Volatile Emissions of Bacillus amyloliquefaciens (BF06

    Directory of Open Access Journals (Sweden)

    Jianfei Wang

    2017-01-01

    Full Text Available Volatile organic compounds (VOCs released by plant growth-promoting rhizobacteria (PGPR are involved in promoting growth and triggering systemic resistance (ISR in plants. Importantly, the release of VOCs by some PGPR strains confers improved plant uptake of nutrient elements from the soil. However, the underlying mechanisms of VOCs-regulated nutrient acquisition remain elusive. In this study, VOCs were extracted and identified from Bacillus amyloliquefaciens (strain BF06 using gas chromatography–mass spectrometry (GC–MS. BF06 VOCs exposure significantly promoted the growth and photosynthesis of Arabidopsis plants. To explore how microbial VOCs stimulate growth in plants, gene expression profiles of Arabidopsis seedlings exposed to BF06 VOCs were examined using transcriptomic analyses. In screening differentially expressed genes (DEGs, most upregulated DEGs were found to be related to amino acid transport, iron (Fe uptake and homeostasis, and sulfate transport. Furthermore, BF06 VOCs significantly enhanced Fe absorption in plants under Fe-limited conditions. However, when nitric oxide (NO synthesis was inhibited, BF06 VOCs exposure could not substantially augment Fe acquisition in plants under alkaline stress, indicating that VOCs-mediated plant uptake of Fe was required for induction of root NO accumulation. In addition, BF06 VOCs exposure led to a marked increase in some genes encoding for sulfate transporters, and further increased Se accumulation in plants. Intriguingly, BF06 VOCs exposure failed to increase Se uptake in sultr1;2 mutants, which may indicate that high-level transcription of these sulfate transporters induced by BF06 VOCs was essential for enhancing Se absorption by plants. Taken together, our results demonstrated the potential of VOCs released by this strain BF06 to increase Fe and Se uptake in plants.

  20. Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms.

    Science.gov (United States)

    Fekri, Farnaz; Delos Santos, Ralph Christian; Karshafian, Raffi; Antonescu, Costin N

    2016-01-01

    Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB) is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME) for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR), and distinct mechanism(s) that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may improve targeted

  1. Lymphocyte transformation (by (/sup 3/H)thymidine) in mice infected with Trichinella spiralis

    Energy Technology Data Exchange (ETDEWEB)

    Borojevic, D.; Lalic, R.; Cuperlovic, K. (Institut za Primeni Nuklearne Energije u Poljoprivedri, Veterinarstvu i Sumarstvu, Zemun (Yugoslavia)); Dujic, A. (Belgrade Univ. (Yugoslavia). Medicinski Fakultet)

    1983-05-01

    The blastogenic response of infected and normal mice (to stimulation by specific antigen and nonspecific antigens) was followed by the uptake of (/sup 3/H)thymidine. It was established that there was a minimum number of cells (1 x 10/sup 6/) per culture for these responses to be observed and that for specific stimulation by T. spiralis soluble antigen 10..mu..g per culture gave optimal results.

  2. Arsenate and fluoride enhanced each other's uptake in As-sensitive plant Pteris ensiformis.

    Science.gov (United States)

    Das, Suchismita; de Oliveira, Letuzia M; da Silva, Evandro; Ma, Lena Q

    2017-08-01

    We investigated the effects of arsenate (AsV) and fluoride (F) on each other's uptake in an As-sensitive plant Pteris ensiformis. Plants were exposed to 1) 0.1 × Hoagland solution control, 2) 3.75 mg L -1 As and 1.9, 3.8, or 7.6 mg L -1 F, or 3) 1 mg L -1 F and 3.75 mg L -1 or 7.5 mg L -1 As for 7 d in hydroponics. P. ensiformis accumulated 14.7-32.6 mg kg -1 As at 3.75 mg L -1 AsV, and 99-145 mg kg -1 F at 1 mg L -1 F. Our study revealed that AsV and F increased each other's uptake when co-present. At 1.9 mg L -1 , F increased frond As uptake from 14.7 to 40.3 mg kg -1 , while 7.5 mg L -1 As increased frond F uptake from 99 to 371 mg kg -1 . Although, AsV was the predominant As species in all tissues, F enhanced AsIII levels in the rhizomes and fronds, while the reverse was observed in the roots. Increasing As concentrations also enhanced TBARS and H 2 O 2 in tissues, indicating oxidative stress. However, F alleviated As stress by lowering their levels in the fronds. Frond and root membrane leakage were also evident due to As or F exposure. The results may facilitate better understanding of the mechanisms underlying the co-uptake of As and F in plants. However, the mechanisms of how they enhance each other's uptake in P. ensiformis need further investigation. Published by Elsevier Ltd.

  3. Enhanced cerebral uptake of receptor ligands by modulation of P-glycoprotein function in the blood-brain barrier

    NARCIS (Netherlands)

    Doze, P; Van Waarde, A; Elsinga, P H; Hendrikse, N H; Vaalburg, W

    Low cerebral uptake of some therapeutic drugs can be enhanced by modulation of P-glycoprotein (P-gp), an ATP-driven drug efflux pump at the blood-brain barrier (BBB). We investigated the possibility of increasing cerebral uptake of the beta-adrenergic ligands S-1'-[(18)F]-fluorocarazolol (FCAR) and

  4. Purified glycosaminoglycans from cooked haddock may enhance Fe uptake via endocytosis in a Caco-2 cell culture model

    Science.gov (United States)

    This study aims to understand the enhancing effect of glycosaminoglycans (GAGs), such as chondroitin/dermatan structures, on Fe uptake to Caco-2 cells. High sulfated GAGs were selectively purified from cooked haddock. An in vitro digestion/Caco-2 cell culture model was used to evaluate Fe uptake (ce...

  5. Enhanced Intracellular Uptake of CdTe Quantum Dots by Conjugation of Oligopeptides

    Directory of Open Access Journals (Sweden)

    Moon-Jeong Choi

    2013-01-01

    Full Text Available Arg-Gly-Asp-Ser (RGDS, a typical membrane-permeable carrier peptide, was conjugated with mercaptoisobutyric acid-immobilized CdTe quantum dot (CTNPs to enhance the intracellular uptake of quantum dots. Mean size of mercaptoisobutyric acid-immobilized quantum dots (37 nm as determined by dynamic light scattering was increased up to 54 nm after RGDS immobilization. It was found, from in vitro cell culture experiment, that fibroblast (NIH 3T3 cells were well proliferated in the presence of RGDS-conjugated quantum dots (RCTNPs, and the intracellular uptake of CTNPs and RCTNPs was studied by means of ICP and fluorescence microscopy. As a result, the RCTNPs specifically bound to the membrane of NIH 3T3 cells and almost saturated after 6 hours incubation. The amount of RCTNPs uptaken by the cells was higher than that of CTNPs, demonstrating the enhancing effect of RGDS peptide conjugation on the intracellular uptake of quantum dots (QDs.

  6. Genome dynamics of short oligonucleotides: the example of bacterial DNA uptake enhancing sequences.

    Directory of Open Access Journals (Sweden)

    Mohammed Bakkali

    Full Text Available Among the many bacteria naturally competent for transformation by DNA uptake-a phenomenon with significant clinical and financial implications- Pasteurellaceae and Neisseriaceae species preferentially take up DNA containing specific short sequences. The genomic overrepresentation of these DNA uptake enhancing sequences (DUES causes preferential uptake of conspecific DNA, but the function(s behind this overrepresentation and its evolution are still a matter for discovery. Here I analyze DUES genome dynamics and evolution and test the validity of the results to other selectively constrained oligonucleotides. I use statistical methods and computer simulations to examine DUESs accumulation in Haemophilus influenzae and Neisseria gonorrhoeae genomes. I analyze DUESs sequence and nucleotide frequencies, as well as those of all their mismatched forms, and prove the dependence of DUESs genomic overrepresentation on their preferential uptake by quantifying and correlating both characteristics. I then argue that mutation, uptake bias, and weak selection against DUESs in less constrained parts of the genome combined are sufficient enough to cause DUESs accumulation in susceptible parts of the genome with no need for other DUES function. The distribution of overrepresentation values across sequences with different mismatch loads compared to the DUES suggests a gradual yet not linear molecular drive of DNA sequences depending on their similarity to the DUES. Other genomically overrepresented sequences, both pro- and eukaryotic, show similar distribution of frequencies suggesting that the molecular drive reported above applies to other frequent oligonucleotides. Rare oligonucleotides, however, seem to be gradually drawn to genomic underrepresentation, thus, suggesting a molecular drag. To my knowledge this work provides the first clear evidence of the gradual evolution of selectively constrained oligonucleotides, including repeated, palindromic and protein

  7. Carbon Nanotubes Enhance CpG Uptake and Potentiate Anti-Glioma Immunity

    Science.gov (United States)

    Zhao, Dongchang; Alizadeh, Darya; Zhang, Leying; Liu, Wei; Farrukh, Omar; Manuel, Edwin; Diamond, Don J.; Badie, Behnam

    2010-01-01

    Purpose Stimulation of toll-like receptor-9 (TLR9) by CpG oligodeoxynucleotides (CpG) has been shown to counteract the immunosuppressive microenvironment and to inhibit tumor growth in glioma models. Since TLR9 is located intracellularly, we hypothesized that methods that enhance its internalization may also potentiate its immunostimulatory response. The goal of this study was to evaluate carbon nanotubes (CNTs) as a CpG delivery vehicle in brain tumor models. Experimental Design Functionalized single-walled CNTs were conjugated with CpG (CNT-CpG) and evaluated in vitro and in mice bearing intracranial GL261 gliomas. Flow cytometry was used to assess CNT-CpG uptake and anti-glioma immune response. Tumor growth was measured by bioluminescent imaging, histology, and animal survival. Results CNT-CpG was nontoxic and enhanced CpG uptake both in vitro and intracranial gliomas. CNT-mediated CpG delivery also potentiated pro-inflammatory cytokine production by primary monocytes. Interestingly, a single intracranial injection of low-dose CNT-CpG (but not free CpG or blank CNT) eradicated intracranial GL261 gliomas in half of tumor-bearing mice. Moreover, surviving animals exhibited durable tumor-free remission (> 3 months), and were protected from intracranial tumor rechallenge, demonstrating induction of long-term anti-tumor immunity. Conclusions These findings suggest that CNTs can potentiate CpG immunopotency by enhancing its delivery into tumor-associated inflammatory cells. PMID:21088258

  8. Carbon nanotubes enhance CpG uptake and potentiate antiglioma immunity.

    Science.gov (United States)

    Zhao, Dongchang; Alizadeh, Darya; Zhang, Leying; Liu, Wei; Farrukh, Omar; Manuel, Edwin; Diamond, Don J; Badie, Behnam

    2011-02-15

    Stimulation of toll-like receptor-9 (TLR9) by CpG oligodeoxynucleotides (CpG) has been shown to counteract the immunosuppressive microenvironment and to inhibit tumor growth in glioma models. Because TLR9 is located intracellularly, we hypothesized that methods that enhance its internalization may also potentiate its immunostimulatory response. The goal of this study was to evaluate carbon nanotubes (CNT) as a CpG delivery vehicle in brain tumor models. Functionalized single-walled CNTs were conjugated with CpG (CNT-CpG) and evaluated in vitro and in mice bearing intracranial GL261 gliomas. Flow cytometry was used to assess CNT-CpG uptake and antiglioma immune response. Tumor growth was measured by bioluminescent imaging, histology, and animal survival. CNT-CpG was nontoxic and enhanced CpG uptake both in vitro and intracranial gliomas. CNT-mediated CpG delivery also potentiated proinflammatory cytokine production by primary monocytes. Interestingly, a single intracranial injection of low-dose CNT-CpG (but not free CpG or blank CNT) eradicated intracranial GL261 gliomas in half of tumor-bearing mice. Moreover, surviving animals exhibited durable tumor-free remission (>3 months), and were protected from intracranial tumor rechallenge, demonstrating induction of long-term antitumor immunity. These findings suggest that CNTs can potentiate CpG immunopotency by enhancing its delivery into tumor-associated inflammatory cells. ©2010 AACR.

  9. Inhibition of BRD4 suppresses tumor growth and enhances iodine uptake in thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Xuemei [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Wu, Xinchao [Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Zhang, Xiao; Hua, Wenjuan; Zhang, Yajing [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Maimaiti, Yusufu [Department of Thyroid and Breast Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Gao, Zairong, E-mail: gaobonn@163.com [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Zhang, Yongxue [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China)

    2016-01-15

    Thyroid cancer is a common malignancy of the endocrine system. Although radioiodine {sup 131}I treatment on differentiated thyroid cancer is widely used, many patients still fail to benefit from {sup 131}I therapy. Therefore, exploration of novel targeted therapies to suppress tumor growth and improve radioiodine uptake remains necessary. Bromodomain-containing protein 4 (BRD4) is an important member of the bromodomain and extra terminal domain family that influences transcription of downstream genes by binding to acetylated histones. In the present study, we found that BRD4 was up-regulated in thyroid cancer tissues and cell lines. Inhibition of BRD4 in thyroid cancer cells by JQ1 resulted in cell cycle arrest at G0/G1 phase and enhanced {sup 131}I uptake in vitro and suppressed tumor growth in vivo. Moreover, JQ1 treatment suppressed C-MYC but enhanced NIS expression. We further demonstrated that BRD4 was enriched in the promoter region of C-MYC, which could be markedly blocked by JQ1 treatment. In conclusion, our findings revealed that the aberrant expression of BRD4 in thyroid cancer is possibly involved in tumor progression, and JQ1 is potentially an effective chemotherapeutic agent against human thyroid cancer. - Highlights: • BRD4 is upregulated in thyroid cancer tissues and cell lines. • Inhibition of BRD4 induced cell cycle arrest and enhanced radioiodine uptake in vitro and impaired tumor growth in vivo. • JQ1 suppressed the expression of C-MYC and promoted the expression of NIS and P21. • JQ1 attenuated the recruitment of BRD4 to MYC promoter in thyroid cancer.

  10. Intestinal adaptation during lactation in the mouse. I. Enhanced intestinal uptake of dietary protein antigen.

    Science.gov (United States)

    Harmatz, P R; Bloch, K J; Brown, M; Walker, W A; Kleinman, R E

    1989-01-01

    Small quantities of dietary protein antigens cross the intestinal epithelium of the lactating mouse, enter the circulation, are transferred across the mammary gland into the milk and reach the suckling neonate. In this study, we sought to determine whether intestinal uptake of ovalbumin (OVA) was enhanced in lactating compared to control mice. OVA was administered by gavage under ether anaesthesia. Blood was obtained at 15, 30, 60 and 120 min and immunoreactive OVA (iOVA) measured by enzyme immunoassay. At 30 and 60 min, a three- to four-fold higher concentration of iOVA was detected in lactating compared to control mice. Because this increase in concentration of iOVA might be explained by changes in plasma volume, rate of clearance of OVA from the circulation or altered uptake from the intestine, plasma volume was measured by isotope dilution after i.v. injection of 125I-bovine serum albumin (BSA) and clearance was assessed by measuring elimination of OVA from the circulation after i.v. injection of OVA. In comparison to controls, plasma volume of Day 7-10 lactating mice was increased two-fold and no difference in clearance rate was noted. Because the increase in concentration of iOVA in lactating mice is several-fold greater than in controls, we suggest that increased intestinal uptake of the protein occurs during lactation. PMID:2737698

  11. Molecular moment similarity between several nucleoside analogs of thymidine and thymidine. sil@watson.ibm.com.

    Science.gov (United States)

    Silverman, B D; Pitman, M C; Platt, D E

    1999-06-01

    Molecular moment descriptors of the shape and charge distributions of twenty five nucleoside structures have been examined. The structures include thymidine as well as the difluorotoluene nucleoside analog which has been found to pair efficiently with adenine by polymerase catalysis. The remaining twenty three structures have been chosen to be as structurally similar to thymidine and to the difluorotoluene nucleoside analog as possible. The moment descriptors which include a description of the relationship of molecular charge to shape show the difluorotoluene nucleoside to be one of the most proximate molecules to thymidine in the space of the molecular moments. The calculations, therefore, suggest that polymerase specificity might be not only a consequence of molecular steric features alone but also of the molecular electrostatic environment and its registration with molecular shape.

  12. Multiwalled carbon nanotubes enter broccoli cells enhancing growth and water uptake of plants exposed to salinity.

    Science.gov (United States)

    Martínez-Ballesta, M Carmen; Zapata, Lavinia; Chalbi, Najla; Carvajal, Micaela

    2016-06-08

    Carbon nanotubes have been shown to improve the germination and growth of some plant species, extending the applicability of the emerging nano-biotechnology field to crop science. In this work, exploitation of commercial multiwalled carbon nanotubes (MWCNTs) in control and 100 mM NaCl-treated broccoli was performed. Transmission electron microscopy demonstrated that MWCNTs can enter the cells in adult plants with higher accumulation under salt stress. Positive effect of MWCNTs on growth in NaCl-treated plants was consequence of increased water uptake, promoted by more-favourable energetic forces driving this process, and enhanced net assimilation of CO2. MWCNTs induced changes in the lipid composition, rigidity and permeability of the root plasma membranes relative to salt-stressed plants. Also, enhanced aquaporin transduction occurred, which improved water uptake and transport, alleviating the negative effects of salt stress. Our work provides new evidences about the effect of MWCNTs on plasma membrane properties of the plant cell. The positive response to MWCNTs in broccoli plants opens novel perspectives for their technological uses in new agricultural practices, especially when 1plants are exposed to saline environments.

  13. In vivo PET imaging with {sup 18}F-FHBG of hepatoma cancer gene therapy using herpes simplex virus thymidine kinase and ganciclovir

    Energy Technology Data Exchange (ETDEWEB)

    Lee, TaeSup; Kim, JunYoup; Moon, ByungSeok; Kang, JooHyun; Song, Inho; Kwon, HeeChung; Kim, KyungMin; Cheon, GiJeong; Choi, ChangWoon; Lim, SangMoo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2007-07-01

    Monitoring gene expression in vivo to evaluate the gene therapy efficacy is a critical issue for scientists and physicians. Non-invasive nuclear imaging can offer information regarding the level of gene expression and its location when an appropriate reporter gene is constructed in the therapeutic gene therapy. Herpes simplex virus type 1 thymidine kinase gene (HSV1-tk) is the most common reporter gene and is used in cancer gene therapy by activating relatively nontoxic compounds, such as acyclovir or ganciclovir (GCV), to induce cell death. In this study, we investigate the feasibility of monitoring cancer gene therapy using retroviral vector transduced HSV1-tk and GCV, in vitro cellular uptake and in vivo animal studies, including biodistribution and small animal positron emission tomography (PET) imaging, were performed in HSV1-tk and luciferase (Luc)-transduced MCA-TK/Luc and enhanced green fluorescent protein (eGFP)-transduced MCA-eGFP hepatoma cell lines.

  14. (S)-[6]-Gingerol enhances glucose uptake in L6 myotubes by activation of AMPK in response to [Ca2+]i.

    Science.gov (United States)

    Li, Yiming; Tran, Van H; Koolaji, Nooshin; Duke, Colin; Roufogalis, Basil D

    2013-01-01

    The aim of this study was to investigate the mechanism of (S)-[6]-gingerol in promoting glucose uptake in L6 skeletal muscle cells. The effect of (S)-[6]-gingerol on glucose uptake in L6 myotubes was examined using 2-[1,2-3H]-deoxy-D-glucose. Intracellular Ca2+ concentration was measured using Fluo-4. Phosphorylation of AMPKα was determined by Western blotting analysis. (S)-[6]-Gingerol time-dependently enhanced glucose uptake in L6 myotubes. (S)-[6]-Gingerol elevated intracellular Ca2+ concentration and subsequently induced a dose- and time-dependent enhancement of threonine172 phosphorylated AMPKα in L6 myotubes via modulation by Ca2+/calmodulin-dependent protein kinase kinase. The results indicated that (S)-[6]-gingerol increased glucose uptake in L6 skeletal muscle cells by activating AMPK. (S)-[6]-gingerol, a major component of Zingiber officinale, may have potential for development as an antidiabetic agent.

  15. Photoreaction of 8-methoxypsoralen with thymidine

    Energy Technology Data Exchange (ETDEWEB)

    Shim, S.C.; Kim, Y.Z. (Korea Advanced Inst. of Science and Technology, Seoul (Republic of Korea))

    1983-09-01

    The photoreaction of 8-methoxypsoralen (8-MOP) with thymidine in solid film state yielded two 4',5'-monoadducts (a pair of diastereomers) and three 3,4-monoadducts. The stereochemistry of two 4',5'monoadducts was found to be cis-syn and trans-syn and one 3,4-monoadduct was cis-anti. In addition to these monoadducts, 3,4-, 4',5-biadducts were also formed during the reaction, but the isolation of each isomer of these adducts was not successful; however, the formation of these biadducts was confirmed by UV, IR, TLC and photosplitting experiments.

  16. Enhanced cellular uptake of antisecretory peptide AF-16 through proteoglycan binding.

    Science.gov (United States)

    Matson Dzebo, Maria; Reymer, Anna; Fant, Kristina; Lincoln, Per; Nordén, Bengt; Rocha, Sandra

    2014-10-21

    Peptide AF-16, which includes the active site of Antisecretory Factor protein, has antisecretory and anti-inflammatory properties, making it a potent drug candidate for treatment of secretory and inflammatory diseases such as diarrhea, inflammatory bowel diseases, and intracranial hypertension. Despite remarkable physiological effects and great pharmaceutical need for drug discovery, very little is yet understood about AF-16 mechanism of action. In order to address interaction mechanisms, we investigated the binding of AF-16 to sulfated glycosaminoglycan, heparin, with focus on the effect of pH and ionic strength, and studied the influence of cell-surface proteoglycans on cellular uptake efficiency. Confocal laser scanning microscopy and flow cytometry experiments on wild type and proteoglycan-deficient Chinese hamster ovary cells reveal an endocytotic nature of AF-16 cellular uptake that is, however, less efficient for the cells lacking cell-surface proteoglycans. Isothermal titration calorimetry provides quantitative thermodynamic data and evidence for that the peptide affinity to heparin increases at lower pH and ionic strength. Experimental data, supported by theoretical modeling, of peptide-glycosaminoglycan interaction indicate that it has a large electrostatic contribution, which will be enhanced in diseases accompanied by decreased pH and ionic strength. These observations show that cell-surface proteoglycans are of general and crucial importance for the antisecretory and anti-inflammatory activities of AF-16.

  17. Bioactive Peptides Isolated from Casein Phosphopeptides Enhance Calcium and Magnesium Uptake in Caco-2 Cell Monolayers.

    Science.gov (United States)

    Cao, Yong; Miao, Jianyin; Liu, Guo; Luo, Zhen; Xia, Zumeng; Liu, Fei; Yao, Mingfei; Cao, Xiaoqiong; Sun, Shengwei; Lin, Yanyin; Lan, Yaqi; Xiao, Hang

    2017-03-22

    The ability of casein phosphopeptides (CPPs) to bind and transport minerals has been previously studied. However, the single bioactive peptides responsible for the effects of CPPs have not been identified. This study was to purify calcium-binding peptides from CPPs and to determine their effects on calcium and magnesium uptake by Caco-2 cell monolayers. Five monomer peptides designated P1 to P5 were isolated and the amino acid sequences were determined using LC-MS/MS. Compared with the CPP-free control, all five monomeric peptides exhibited significant enhancing effects on the uptake of calcium and magnesium (P magnesium were presented simultaneously with P5, magnesium was taken up with priority over calcium in the Caco-2 cell monolayers. For example, at 180 min, the amount of transferred magnesium and calcium was 78.4 ± 0.95 μg/well and 2.56 ± 0.64 μg/well, respectively, showing a more than 30-fold difference in the amount of transport caused by P5. These results provide novel insight into the mineral transport activity of phosphopeptides obtained from casein.

  18. Nanocrystalline diamond protects Zr cladding surface against oxygen and hydrogen uptake: Nuclear fuel durability enhancement.

    Science.gov (United States)

    Škarohlíd, Jan; Ashcheulov, Petr; Škoda, Radek; Taylor, Andrew; Čtvrtlík, Radim; Tomáštík, Jan; Fendrych, František; Kopeček, Jaromír; Cháb, Vladimír; Cichoň, Stanislav; Sajdl, Petr; Macák, Jan; Xu, Peng; Partezana, Jonna M; Lorinčík, Jan; Prehradná, Jana; Steinbrück, Martin; Kratochvílová, Irena

    2017-07-25

    In this work, we demonstrate and describe an effective method of protecting zirconium fuel cladding against oxygen and hydrogen uptake at both accident and working temperatures in water-cooled nuclear reactor environments. Zr alloy samples were coated with nanocrystalline diamond (NCD) layers of different thicknesses, grown in a microwave plasma chemical vapor deposition apparatus. In addition to showing that such an NCD layer prevents the Zr alloy from directly interacting with water, we show that carbon released from the NCD film enters the underlying Zr material and changes its properties, such that uptake of oxygen and hydrogen is significantly decreased. After 100-170 days of exposure to hot water at 360 °C, the oxidation of the NCD-coated Zr plates was typically decreased by 40%. Protective NCD layers may prolong the lifetime of nuclear cladding and consequently enhance nuclear fuel burnup. NCD may also serve as a passive element for nuclear safety. NCD-coated ZIRLO claddings have been selected as a candidate for Accident Tolerant Fuel in commercially operated reactors in 2020.

  19. Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

    Directory of Open Access Journals (Sweden)

    Xuzhu Lin

    2017-11-01

    Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

  20. Edge effects enhance carbon uptake and its vulnerability to climate change in temperate broadleaf forests.

    Science.gov (United States)

    Reinmann, Andrew B; Hutyra, Lucy R

    2017-01-03

    Forest fragmentation is a ubiquitous, ongoing global phenomenon with profound impacts on the growing conditions of the world's remaining forest. The temperate broadleaf forest makes a large contribution to the global terrestrial carbon sink but is also the most heavily fragmented forest biome in the world. We use field measurements and geospatial analyses to characterize carbon dynamics in temperate broadleaf forest fragments. We show that forest growth and biomass increase by 89 ± 17% and 64 ± 12%, respectively, from the forest interior to edge, but ecosystem edge enhancements are not currently captured by models or approaches to quantifying regional C balance. To the extent that the findings from our research represent the forest of southern New England in the United States, we provide a preliminary estimate that edge growth enhancement could increase estimates of the region's carbon uptake and storage by 13 ± 3% and 10 ± 1%, respectively. However, we also find that forest growth near the edge declines three times faster than that in the interior in response to heat stress during the growing season. Using climate projections, we show that future heat stress could reduce the forest edge growth enhancement by one-third by the end of the century. These findings contrast studies of edge effects in the world's other major forest biomes and indicate that the strength of the temperate broadleaf forest carbon sink and its capacity to mitigate anthropogenic carbon emissions may be stronger, but also more sensitive to climate change than previous estimates suggest.

  1. Synthesis and evaluation of a {sup 99m}Tc-MAMA-propyl-thymidine complex as a potential probe for in vivo visualization of tumor cell proliferation with SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Celen, Sofie [Laboratory for Radiopharmacy, K.U. Leuven, B-3000 Leuven (Belgium); Groot, Tjibbe de [Radiopharmacy, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Balzarini, Jan [Rega Institute for Medical Research, K.U. Leuven, B-3000 Leuven (Belgium); Vunckx, Kathleen [Nuclear Medicine, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Terwinghe, Christelle [Radiopharmacy, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Vermaelen, Peter [Nuclear Medicine, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Van Berckelaer, Lizette [Rega Institute for Medical Research, K.U. Leuven, B-3000 Leuven (Belgium); Vanbilloen, Hubert [Radiopharmacy, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Nuyts, Johan [Nuclear Medicine, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Mortelmans, Luc [Nuclear Medicine, U.Z. Gasthuisberg K.U. Leuven, B-3000 Leuven (Belgium); Verbruggen, Alfons [Laboratory for Radiopharmacy, K.U. Leuven, B-3000 Leuven (Belgium); Bormans, Guy [Laboratory for Radiopharmacy, K.U. Leuven, B-3000 Leuven (Belgium)]. E-mail: guy.bormans@pharm.kuleuven.be

    2007-04-15

    Introduction: Cytosolic thymidine kinase (TK1) catalyzes phosphorylation of thymidine to its monophosphate. TK1 activity is closely related with DNA synthesis, and thymidine analogs derivatized with bulky carboranylalkyl groups at the N-3 position were reported to be good substrates for TK1. Accordingly, we have synthesized {sup 99m}Tc-MAMA-propyl-thymidine and evaluated it as a potential tumor tracer. Methods: The bis(S-trityl)-protected MAMA-propyl-thymidine precursor (3-N-[S-trityl-2-mercaptoethyl]-N-[N'-(S-trityl-2-mercaptoethyl) amidoacetyl] -aminopropyl-thymidine) was prepared in three steps, and its structure was confirmed with {sup 1}H NMR and mass spectrometry. Deprotection of the thiols and labeling with {sup 99m}Tc were done in a two-step, one-pot procedure, yielding {sup 99m}Tc-MAMA-propyl-thymidine, which was analyzed with high-performance liquid chromatography, radio-LC-MS analysis (ESI+) and electrophoresis, and its log P was determined. The biodistribution in normal mice was evaluated, and its biodistribution in a radiation-induced fibrosarcoma (RIF) tumor mouse was compared with that of 3'-deoxy-3'-[{sup 18}F] fluorothymidine [{sup 18}F]FLT. Results: {sup 99m}Tc-MAMA-propyl-thymidine was obtained with a radiochemical yield of 70%. Electrophoresis indicated that the complex is uncharged, and its log P was 1.0. The molecular ion mass of the Tc complex was 589 Da, which is compatible with the hypothesized N{sub 2}S{sub 2}-oxotechnetium structure. Tissue distribution showed fast clearance from plasma primarily by the hepatobiliary pathway. Whole-body planar imaging after injection of {sup 99m}Tc-MAMA-propyl-thymidine in an RIF tumor-bearing mouse showed high uptake in the liver and the intestines. No uptake was observed in the tumor, in contrast to the clear uptake observed for [{sup 18}F] FLT visualized with {mu}PET. Conclusions: Although it has been reported that TK1 accepts large substituents at the N-3 position of the thymine ring

  2. Reconstitution of an efficient thymidine salvage pathway in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Vernis, L.; Piskur, Jure; Diffley, J.F.X.

    2003-01-01

    as an equilibrative nucleoside transporter. By also deleting the gene encoding thymidylate synthase (CDC21) we have constructed strains that are entirely dependent upon exogenous thymidine for viability and that can grow with normal kinetics at low thymidine concentrations. Using this novel approach, we show...

  3. Successful Stabilization of Graphene Oxide in Electrolyte Solutions: Enhancement of Bio-functionalization and Cellular Uptake

    Science.gov (United States)

    Hong, Bong Jin; Compton, Owen C.; An, Zhi; Eryzazici, Ibrahim; Nguyen, SonBinh T.

    2013-01-01

    Aqueous dispersions of graphene oxide are inherently unstable in the presence of electrolytes, which screen the electrostatic surface charge on these nanosheets and induce irreversible aggregation. Two complementary strategies, utilizing either electrostatic or steric stabilization, have been developed to enhance the stability of graphene oxide in electrolyte solutions, allowing it to stay dispersed in cell culture media and serum. The electrostatic stabilization approach entails further oxidation of graphene oxide to low C/O ratio (~1.03) and increases ionic tolerance of these nanosheets. The steric stabilization technique employs an amphiphilic block copolymer that serves as a non-covalently bound surfactant to minimize the aggregate-induced nanosheets-nanosheet interactions. Both strategies can stabilize graphene oxide nanosheets with large dimensions (>300 nm) in biological media, allowing for an enhancement of >250% in the bioconjugation efficiency of streptavidin in comparison to untreated nanosheets. Notably, both strategies allow the stabilized nanosheets to be readily uptake by cells, demonstrating their excellent performance as potential drug delivery vehicles. PMID:22017285

  4. Urea uptake enhances barrier function and antimicrobial defense in humans by regulating epidermal gene expression

    Science.gov (United States)

    Grether-Beck, Susanne; Felsner, Ingo; Brenden, Heidi; Kohne, Zippora; Majora, Marc; Marini, Alessandra; Jaenicke, Thomas; Rodriguez-Martin, Marina; Trullas, Carles; Hupe, Melanie; Elias, Peter M.; Krutmann, Jean

    2012-01-01

    Urea is an endogenous metabolite, known to enhance stratum corneum hydration. Yet, topical urea anecdotally also improves permeability barrier function, and it appears to exhibit antimicrobial activity. Hence, we hypothesized that urea is not merely a passive metabolite, but a small-molecule regulator of epidermal structure and function. In 21 human volunteers, topical urea improved barrier function in parallel with enhanced antimicrobial peptide (LL-37 and β-defensin-2) expression. Urea both stimulates expression of, and is transported into keratinocytes by two urea transporters, UT-A1 and UT-A2, and by aquaporin 3, 7 and 9. Inhibitors of these urea transporters block the downstream biological effects of urea, which include increased mRNA and protein levels for: (i) transglutaminase-1, involucrin, loricrin and filaggrin; (ii) epidermal lipid synthetic enzymes, and (iii) cathelicidin/LL-37 and β-defensin-2. Finally, we explored the potential clinical utility of urea, showing that topical urea applications normalized both barrier function and antimicrobial peptide expression in a murine model of atopic dermatitis (AD). Together, these results show that urea is a small-molecule regulator of epidermal permeability barrier function and antimicrobial peptide expression after transporter uptake, followed by gene regulatory activity in normal epidermis, with potential therapeutic applications in diseased skin. PMID:22418868

  5. Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas Møller; Treebak, Jonas Thue; Schjerling, Peter

    2014-01-01

    signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase α2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot......Background: Metformin-induced activation of AMPK has been associated with enhanced glucose uptake in skeletal muscle but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent upon AMPK...... analyzes. Results: Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (45%, P...

  6. Enhancement of radioiodine uptake in hyperthyroidism with hydrochlorothiazide: a prospective randomised control study

    Energy Technology Data Exchange (ETDEWEB)

    Tepmongkol, Supatporn [Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330 (Thailand)

    2002-10-01

    The aim of this study was to determine whether hydrochlorothiazide (HCTZ) could improve radioiodine uptake in low-uptake hyperthyroid patients. Eighteen hyperthyroid patients with low 3-h and 24-h iodine-131 uptake were recruited to the study. Eleven patients were assigned to the HCTZ group, and seven to the control group. Two weeks after the first, baseline uptake study, a second uptake study was performed. Patients in both groups had a low-iodine diet after the first uptake study. In the HCTZ group, 50 mg of HCTZ was administered twice a day for 5 days prior to the second uptake study. Improvement in uptake at 3 and 24 h in the second uptake study, as compared with the baseline study, was assessed within and between groups. In the control group, compared with the baseline study there was a significant improvement in uptake at 3 h (P=0.03) but a non-significant improvement at 24 h (P=0.07). In the HCTZ group, significant improvements were observed at both 3 h (P=0.0005) and 24 h (P=2.28 x 10{sup -5}). Patients in the HCTZ group had statistically greater improvement in uptake at both 3 h and 24 h compared with the control group (P=0.003 and 0.0008, respectively). There was a 7.18-fold average improvement in uptake in the HCTZ group at 24 h, compared with only a 1.33-fold improvement in the control group. Administration of HCTZ significantly improves 24-h radioiodine uptake in high-iodide pool, low-uptake hyperthyroid patients compared with patients who have received a low-iodine diet alone. (orig.)

  7. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    Science.gov (United States)

    Kristensen, Jonas Møller; Treebak, Jonas T.; Schjerling, Peter; Goodyear, Laurie

    2014-01-01

    Metformin-induced activation of the 5′-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P metformin treatment. Insulin signaling at the level of Akt and TBC1D4 protein expression as well as Akt Thr308/Ser473 and TBC1D4 Thr642/Ser711 phosphorylation were not changed by metformin treatment. Also, protein expressions of Rab4, GLUT4, and hexokinase II were unaltered after treatment. The acute metformin treatment did not affect glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. PMID:24644243

  8. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle.

    Science.gov (United States)

    Kristensen, Jonas Møller; Treebak, Jonas T; Schjerling, Peter; Goodyear, Laurie; Wojtaszewski, Jørgen F P

    2014-05-15

    Metformin-induced activation of the 5'-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. Copyright © 2014 the American Physiological Society.

  9. Chloroquine Increases Glucose Uptake via Enhancing GLUT4 Translocation and Fusion with the Plasma Membrane in L6 Cells

    Directory of Open Access Journals (Sweden)

    Qi Zhou

    2016-05-01

    Full Text Available Background/Aims: Chloroquine can induce an increase in the cellular uptake of glucose; however, the underlying mechanism is unclear. Methods: In this study, translocation of GLUT4 and intracellular Ca2+ changes were simultaneously observed by confocal microscope in L6 cells stably over-expressing IRAP-mOrange. The GLUT4 fusion with the plasma membrane (PM was traced using HA-GLUT4-GFP. Glucose uptake was measured using a cell-based glucose uptake assay. GLUT4 protein was detected by Western blotting and mRNA level was detected by RT-PCR. Results: We found that chloroquine induced significant increases in glucose uptake, glucose transporter GLUT4 translocation to the plasma membrane (GTPM, GLUT4 fusion with the PM, and intracellular Ca2+ in L6 muscle cells. Chloroquine-induced increases of GTPM and intracellular Ca2+ were inhibited by Gallein (Gβγ inhibitor and U73122 (PLC inhibitor. However, 2-APB (IP3R blocker only blocked the increase in intracellular Ca2+ but did not inhibit GTPM increase. These results indicate that chloroquine, via the Gβγ-PLC-IP3-IP3R pathway, induces elevation of Ca2+, and this Ca2+ increase does not play a role in chloroqui-ne-evoked GTPM increase. However, GLUT4 fusion with the PM and glucose uptake were significantly inhibited with BAPTA-AM. This suggests that Ca2+ enhances GLUT4 fusion with the PM resulting in glucose uptake increase. Conclusion: Our data indicate that chloroquine via Gβγ-PLC-IP3-IP3R induces Ca2+ elevation, which in turn promotes GLUT4 fusion with the PM. Moreover, chloroquine can enhance GLUT4 trafficking to the PM. These mechanisms eventually result in glucose uptake increase in control and insulin-resistant L6 cells. These findings suggest that chloroquine might be a potential drug for improving insulin tolerance in diabetic patients.

  10. Synergistically enhanced selective intracellular uptake of anticancer drug carrier comprising folic acid-conjugated hydrogels containing magnetite nanoparticles

    Science.gov (United States)

    Kim, Haneul; Jo, Ara; Baek, Seulgi; Lim, Daeun; Park, Soon-Yong; Cho, Soo Kyung; Chung, Jin Woong; Yoon, Jinhwan

    2017-01-01

    Targeted drug delivery has long been extensively researched since drug delivery and release at the diseased site with minimum dosage realizes the effective therapy without adverse side effects. In this work, to achieve enhanced intracellular uptake of anticancer drug carriers for efficient chemo-therapy, we have designed targeted multifunctional anticancer drug carrier hydrogels. Temperature-responsive poly(N-isopropylacrylamide) (PNIPAm) hydrogel core containing superparamagnetic magnetite nanoparticles (MNP) were prepared using precipitation polymerization, and further polymerized with amine-functionalized copolymer shell to facilitate the conjugation of targeting ligand. Then, folic acid, specific targeting ligand for cervical cancer cell line (HeLa), was conjugated on the hydrogel surface, yielding the ligand conjugated hybrid hydrogels. We revealed that enhanced intracellular uptake by HeLa cells in vitro was enabled by both magnetic attraction and receptor-mediated endocytosis, which were contributed by MNP and folic acid, respectively. Furthermore, site-specific uptake of the developed carrier was confirmed by incubating with several other cell lines. Based on synergistically enhanced intracellular uptake, efficient cytotoxicity and apoptotic activity of HeLa cells incubated with anticancer drug loaded hybrid hydrogels were successfully achieved. The developed dual-targeted hybrid hydrogels are expected to provide a platform for the next generation intelligent drug delivery systems.

  11. Enhanced vaginal drug delivery through the use of hypotonic formulations that induce fluid uptake.

    Science.gov (United States)

    Ensign, Laura M; Hoen, Timothy E; Maisel, Katharina; Cone, Richard A; Hanes, Justin S

    2013-09-01

    Mucosal epithelia use osmotic gradients for fluid absorption and secretion. We hypothesized that administration of hypotonic solutions would induce fluid uptake that could be advantageous for rapidly delivering drugs through mucus to the vaginal epithelium. We found that hypotonic formulations markedly increased the rate at which small molecule drugs and mucoinert nanoparticles (mucus-penetrating particles, or MPP), but not conventional mucoadhesive nanoparticles (CP), reached the vaginal epithelial surface in vivo in mice. Additionally, hypotonic formulations greatly enhanced drug and MPP delivery to the entire epithelial surface, including deep into the vaginal folds (rugae) that drugs or MPP in isotonic formulations failed to reach efficiently. However, hypotonic formulations caused unencapsulated "free" drugs to be drawn through the epithelium, reducing vaginal retention. In contrast, hypotonic formulations caused MPP to accumulate rapidly and uniformly on vaginal surfaces, ideally positioned for localized sustained drug delivery. Using a mouse model of vaginal genital herpes (HSV-2) infection, we found that hypotonic delivery of free drug led to improved immediate protection, but diminished longer-term protection. In contrast, as we previously demonstrated, hypotonic delivery of drug via MPP led to better long-term retention and protection in the vagina. Importantly, we demonstrate that slightly hypotonic formulations provided rapid and uniform delivery of MPP to the entire vaginal surface, thus enabling formulations with minimal risk of epithelial toxicity. Hypotonic formulations for vaginal drug delivery via MPP may significantly improve prevention and treatment of reproductive tract diseases and disorders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Promoting siRNA delivery via enhanced cellular uptake using an arginine-decorated amphiphilic dendrimer

    Science.gov (United States)

    Liu, Xiaoxuan; Liu, Cheng; Zhou, Jiehua; Chen, Chao; Qu, Fanqi; Rossi, John J.; Rocchi, Palma; Peng, Ling

    2015-02-01

    RNA interference (RNAi) with small interfering RNA (siRNA) is expected to offer an attractive means to specifically and efficiently silence disease-associated genes for treating various diseases provided that safe and efficient delivery systems are available. In this study, we have established an arginine-decorated amphiphilic dendrimer composed of a hydrophobic alkyl chain and a hydrophilic PAMAM dendron bearing arginine terminals as nonviral vector for siRNA delivery. Indeed, this dendrimer proved to be very effective at delivering siRNAs in human prostate cancer PC-3 cells and in human hematopoietic CD34+ stem cells, leading to improved gene silencing compared to the corresponding nonarginine decorated dendrimer. Further investigation confirmed that this dendrimer was granted with the capacity to form stable nanoparticles with siRNA and significantly enhance cellular uptake of siRNA. In addition, this dendrimer revealed no discernible cytotoxicity. All these findings demonstrate that decoration of the dendrimer surface with arginine residues is indeed a useful strategy to improve the delivery ability of dendrimers.

  13. PET imaging of oncolytic VSV expressing the mutant HSV-1 thymidine kinase transgene in a preclinical HCC rat model.

    Science.gov (United States)

    Muñoz-Álvarez, Kim A; Altomonte, Jennifer; Laitinen, Iina; Ziegler, Sibylle; Steiger, Katja; Esposito, Irene; Schmid, Roland M; Ebert, Oliver

    2015-04-01

    Hepatocellular carcinoma (HCC) is the most predominant form of liver cancer and the third leading cause of cancer-related death worldwide. Due to the relative ineffectiveness of conventional HCC therapies, oncolytic viruses have emerged as novel alternative treatment agents. Our previous studies have demonstrated significant prolongation of survival in advanced HCC in rats after oncolytic vesicular stomatitis virus (VSV) treatment. In this study, we aimed to establish a reporter system to reliably and sensitively image VSV in a clinically relevant model of HCC for clinical translation. To this end, an orthotopic, unifocal HCC model in immune-competent Buffalo rats was employed to test a recombinant VSV vector encoding for an enhanced version of the herpes simplex virus 1 (HSV-1) thymidine kinase (sr39tk) reporter, which would allow the indirect detection of VSV via positron emission tomography (PET). The resulting data revealed specific tracer uptake in VSV-HSV1-sr39tk-treated tumors. Further characterization of the VSV-HSV1-sr39tk vector demonstrated its optimal detection time-point after application and its detection limit via PET. In conclusion, oncolytic VSV expressing the HSV1-sr39tk reporter gene allows for highly sensitive in vivo imaging via PET. Therefore, this imaging system may be directly translatable and beneficial in further clinical applications.

  14. A shape memory foam composite with enhanced fluid uptake and bactericidal properties as a hemostatic agent.

    Science.gov (United States)

    Landsman, T L; Touchet, T; Hasan, S M; Smith, C; Russell, B; Rivera, J; Maitland, D J; Cosgriff-Hernandez, E

    2017-01-01

    Uncontrolled hemorrhage accounts for more than 30% of trauma deaths worldwide. Current hemostatic devices focus primarily on time to hemostasis, but prevention of bacterial infection is also critical for improving survival rates. In this study, we sought to improve on current devices used for hemorrhage control by combining the large volume-filling capabilities and rapid clotting of shape memory polymer (SMP) foams with the swelling capacity of hydrogels. In addition, a hydrogel composition was selected that readily complexes with elemental iodine to impart bactericidal properties to the device. The focus of this work was to verify that the advantages of each respective material (SMP foam and hydrogel) are retained when combined in a composite device. The iodine-doped hydrogel demonstrated an 80% reduction in bacteria viability when cultured with a high bioburden of Staphylococcus aureus. Hydrogel coating of the SMP foam increased fluid uptake by 19× over the uncoated SMP foam. The composite device retained the shape memory behavior of the foam with more than 15× volume expansion after being submerged in 37°C water for 15 min. Finally, the expansion force of the composite was tested to assess potential tissue damage within the wound during device expansion. Expansion forces did not exceed 0.6N, making tissue damage during device expansion unlikely, even when the expanded device diameter is substantially larger than the target wound site. Overall, the enhanced fluid uptake and bactericidal properties of the shape memory foam composite indicate its strong potential as a hemostatic agent to treat non-compressible wounds. No hemostatic device currently used in civilian and combat trauma situations satisfies all the desired criteria for an optimal hemostatic wound dressing. The research presented here sought to improve on current devices by combining the large volume-filling capabilities and rapid clotting of shape memory polymer (SMP) foams with the swelling

  15. CD36 enhances fatty acid uptake by increasing the rate of intracellular esterification but not transport across the plasma membrane.

    Science.gov (United States)

    Xu, Su; Jay, Anthony; Brunaldi, Kellen; Huang, Nasi; Hamilton, James A

    2013-10-15

    CD36 is a multifunctional protein that enhances cellular fatty acid (FA) uptake, a key step in energy metabolism, and its dysregulation in multiple tissue sites is central to obesity-linked diabetes, a risk factor for atherosclerosis. Although CD36 has been implicated in FA uptake in a correlative way, the molecular mechanisms are not known. Their elucidation in cells is confounded by receptor-mediated uptake of low-density lipoprotein by CD36 and the competitive and/or contributive effects of other proteins involved in FA transport and metabolism, which include caveolin(s), fatty acid transport protein (FATP), intracellular fatty acid binding protein, and enzymes involved in the conversion of FAs to esters. Here we utilized a simpler cellular system (HEK cells), which lack caveolin-1, CD36, and FATP and metabolize FAs slowly compared to the time frame of transmembrane FA movement. Our previous studies of HEK cells showed that caveolin-1 affects FA binding and translocation across the plasma membrane and but not FA esterification [Simard, J. R., et al. (2010) J. Lipid Res. 51 (5), 914-922]. Our key new finding is that CD36 accelerates FA uptake and extensive incorporation into triglycerides, a process that is slower (minutes) than transmembrane movement (seconds). Real-time fluorescence measurements showed that the rates of binding and transport of oleic acid into cells with and without CD36 were not different. Thus, CD36 enhances intracellular metabolism, i.e., esterification, and thereby increases the rate of FA uptake without catalyzing the translocation of FA across the plasma membrane, suggesting that CD36 is central to FA uptake via its effects on intracellular metabolism.

  16. Reconstitution of an efficient thymidine salvage pathway in Saccharomyces cerevisiae

    Science.gov (United States)

    Vernis, Laurence; Piskur, Jure; Diffley, John F. X.

    2003-01-01

    The budding yeast Saccharomyces cerevisiae is unable to incorporate exogenous nucleosides into DNA. We have made a number of improvements to existing strategies to reconstitute an efficient thymidine salvage pathway in yeast. We have constructed strains that express both a nucleoside kinase as well as an equilibrative nucleoside transporter. By also deleting the gene encoding thymidylate synthase (CDC21) we have constructed strains that are entirely dependent upon exogenous thymidine for viability and that can grow with normal kinetics at low thymidine concentrations. Using this novel approach, we show that depletion of a single deoxyribonucleoside causes reversible arrest of cells in S phase with concomitant phosphorylation and activation of the S phase checkpoint kinase, Rad53. We show that this strain also efficiently incorporates the thymidine analogue, BrdU, into DNA and can be used for pulse–chase labelling. PMID:14500848

  17. Background 99mTc-methoxyisobutylisonitrile uptake of breast-specific gamma imaging in relation to background parenchymal enhancement in magnetic resonance imaging.

    Science.gov (United States)

    Yoon, Hai-Jeon; Kim, Yemi; Lee, Jee Eun; Kim, Bom Sahn

    2015-01-01

    This study investigated factors that could affect background uptake of (99m)Tc- methoxyisobutylisonitrile (MIBI) on normal breast by breast-specific gamma imaging (BSGI). In addition, the impact of background (99m)Tc-MIBI uptake on the diagnostic performance of BSGI was further investigated. One hundred forty-five women with unilateral breast cancer who underwent BSGI, MRI, and mammography were retrospectively enrolled. Background uptake on BSGI was evaluated qualitatively and quantitatively. Patients were classified into non-dense and dense breast groups according to mammographic breast density. Background parenchymal enhancement (BPE) was rated according to BI-RADS classification. The relationship of age, menopausal status, mammographic breast density, and BPE with background (99m)Tc-MIBI uptake was analyzed. Heterogeneous texture and high background uptake ratio on BSGI were significantly correlated with younger age (p background MIBI uptake (p background MIBI uptake and BPE grade increased. BPE on MRI was the most important factor for background MIBI uptake on BSGI. High background MIBI uptake or marked BPE can diminish the diagnostic performance of BSGI. • Age, menopause, density, and background parenchymal enhancement affect background MIBI uptake. • BPE is an independent factor for background MIBI uptake on BSGI. • Marked BPE may impair BSGI interpretation.

  18. Social capital strategies to enhance hepatitis C treatment awareness and uptake among men in prison.

    Science.gov (United States)

    Lafferty, L; Treloar, C; Guthrie, J; Chambers, G M; Butler, T

    2017-02-01

    Prisoner populations are characterized by high rates of hepatitis C (HCV), up to thirty times that of the general population in Australia. Within Australian prisons, less than 1% of eligible inmates access treatment. Public health strategies informed by social capital could be important in addressing this inequality in access to HCV treatment. Twenty-eight male inmates participated in qualitative interviews across three correctional centres in New South Wales, Australia. All participants had recently tested as HCV RNA positive or were receiving HCV treatment. Analysis was conducted with participants including men with experiences of HCV treatment (n=10) (including those currently accessing treatment and those with a history of treatment) and those who were treatment naïve (n=18). Social capital was a resourceful commodity for inmates considering and undergoing treatment while in custody. Inmates were a valuable resource for information regarding HCV treatment, including personal accounts and reassurance (bonding social capital), while nurses a resource for the provision of information and care (linking social capital). Although linking social capital between inmates and nurses appeared influential in HCV treatment access, there remained opportunities for increasing linking social capital within the prison setting (such as nurse-led engagement within the prisons). Bonding and linking social capital can be valuable resources in promoting HCV treatment awareness, uptake and adherence. Peer-based programmes are likely to be influential in promoting HCV outcomes in the prison setting. Engagement in prisons, outside of the clinics, would enhance opportunities for linking social capital to influence HCV treatment outcomes. © 2016 John Wiley & Sons Ltd.

  19. Prevention of Cutaneous Penetration and CD1c+ Uptake of Pollen Allergens by a Barrier-Enhancing Formulation.

    Science.gov (United States)

    Meinke, Martina Claudia; Schanzer, Sabine; Richter, Heike; Rippke, Frank; Filbry, Alexander; Bohnsack, Kerstin; Patzelt, Alexa; Lademann, Jürgen

    2016-01-01

    Recent studies have shown that pollen proteins can penetrate the impaired skin barrier of atopic patients and exacerbate their disease. In the presented study the effect of a topically applied barrier-enhancing formulation was investigated for its preventive effect on the uptake of pollen allergens into CD1c+ epidermal cells. The pollen proteins were fluorescence labelled and applied on barrier-disrupted excised human skin. CD1c+ cells were selected after magnetic cell sorting and analysed using laser scanning microscopy. In untreated disrupted skin, 81% of the CD1c+ cells contained the fluorescence-labelled pollen allergens. In formulation-pretreated skin only 12% of the CD1c+ cells showed an uptake of pollen allergens. These results encourage the treatment of atopic patients with barrier-enhancing formulations to reduce the impact of pollen on air-exposed skin areas and hence the exacerbation of cutaneous symptoms. © 2016 S. Karger AG, Basel.

  20. Black pepper and piperine reduce cholesterol uptake and enhance translocation of cholesterol transporter proteins.

    Science.gov (United States)

    Duangjai, Acharaporn; Ingkaninan, Kornkanok; Praputbut, Sakonwun; Limpeanchob, Nanteetip

    2013-04-01

    Black pepper (Piper nigrum L.) lowers blood lipids in vivo and inhibits cholesterol uptake in vitro, and piperine may mediate these effects. To test this, the present study aimed to compare actions of black pepper extract and piperine on (1) cholesterol uptake and efflux in Caco-2 cells, (2) the membrane/cytosol distribution of cholesterol transport proteins in these cells, and (3) the physicochemical properties of cholesterol micelles. Piperine or black pepper extract (containing the same amount of piperine) dose-dependently reduced cholesterol uptake into Caco-2 cells in a similar manner. Both preparations reduced the membrane levels of NPC1L1 and SR-BI proteins but not their overall cellular expression. Micellar cholesterol solubility of lipid micelles was unaffected except by 1 mg/mL concentration of black pepper extract. These data suggest that piperine is the active compound in black pepper and reduces cholesterol uptake by internalizing the cholesterol transporter proteins.

  1. Curcumin uptake enhancement using low dose light illumination during incubation in Candida albicans

    Science.gov (United States)

    Romano, Renan A.; Pratavieira, Sebastião.; da Silva, Ana P.; Kurachi, Cristina; Bagnato, Vanderlei S.; Guimarães, Francisco E. G.

    2017-07-01

    A new PDI protocol is presented in this study. C. albicans cells pre-illuminated with a low dose light demonstrated an increase of curcumin uptake when compared to dark incubation, leading to a higher PDI efficacy.

  2. Modeling of Stomatal Conductance for Estimating Ozone Uptake of Fagus crenata Under Experimentally Enhanced Free-air Ozone Exposure

    OpenAIRE

    Hoshika, Yasutomo; Watanabe, Makoto; Inada, Naoki; Koike, Takayoshi

    2012-01-01

    We examined a performance of the multiplicative stomatal conductance model to estimate the stomatal ozone uptake for Fagus crenata. Parameterization of the model was carried out by in-situ measurements in a free-air ozone exposure experiment. The model performed fairly well under ambient conditions, with low ozone concentration. However, the model overestimated stomatal conductance under enhanced ozone condition due to ozone-induced stomatal closure. A revised model that included a parameter ...

  3. Prodrugs of herpes simplex thymidine kinase inhibitors.

    Science.gov (United States)

    Yanachkova, Milka; Xu, Wei-Chu; Dvoskin, Sofya; Dix, Edward J; Yanachkov, Ivan B; Focher, Federico; Savi, Lida; Sanchez, M Dulfary; Foster, Timothy P; Wright, George E

    2015-04-01

    Because guanine-based herpes simplex virus thymidine kinase inhibitors are not orally available, we synthesized various 6-deoxy prodrugs of these compounds and evaluated them with regard to solubility in water, oral bioavailability, and efficacy to prevent herpes simplex virus-1 reactivation from latency in a mouse model. Organic synthesis was used to prepare compounds, High Performance Liquid Chromatography (HPLC) to analyze hydrolytic conversion, Mass Spectrometry (MS) to measure oral bioavailability, and mouse latent infection and induced reactivation to evaluate the efficacy of a specific prodrug. Aqueous solubilities of prodrugs were improved, oxidation of prodrugs by animal cytosols occurred in vitro, and oral absorption of the optimal prodrug sacrovir™ (6-deoxy-mCF3PG) in the presence of the aqueous adjuvant Soluplus® and conversion to active compound N(2)-[3-(trifluoromethyl)pheny])guanine (mCF3PG) were accomplished in mice. Treatment of herpes simplex virus-1 latent mice with sacrovir™ in 1% Soluplus in drinking water significantly suppressed herpes simplex virus-1 reactivation and viral genomic replication. Ad libitum oral delivery of sacrovir™ was effective in suppressing herpes simplex virus-1 reactivation in ocularly infected latent mice as measured by the numbers of mice shedding infectious virus at the ocular surface, numbers of trigeminal ganglia positive for infectious virus, number of corneas that had detectable infectious virus, and herpes simplex virus-1 genome copy numbers in trigeminal ganglia following reactivation. These results demonstrate the statistically significant effect of the prodrug on suppressing herpes simplex virus-1 reactivation in vivo. © The Author(s) 2015.

  4. CETP expression enhances liver HDL-cholesteryl ester uptake but does not alter VLDL and biliary lipid secretion.

    Science.gov (United States)

    Harada, Lila M; Amigo, Ludwig; Cazita, Patrícia M; Salerno, Alessandro G; Rigotti, Attilio A; Quintão, Eder C R; Oliveira, Helena C F

    2007-04-01

    The aim of this work was to study how CETP expression affects whole body cholesterol homeostasis. Thus, tissue uptake and plasma removal rates of labeled HDL-cholesteryl ester (CE), VLDL secretion rates, and biliary lipid secretion and fecal bile acid content were compared between human CETP transgenic (Tg) and non-transgenic (nTg) mice fed with a standard diet. CETP Tg mice exhibited increased HDL-CE plasma fractional catabolic rate and uptake by the liver, adrenals, adipose tissue and spleen. HDL fractions from both CETP Tg and from nTg mice were removed faster from the plasma of CETP expressing than from nTg mice, suggesting a direct role of CETP in accelerating tissue CE uptake. However, neither hepatic output of VLDL cholesterol and triglycerides nor biliary lipid and fecal bile acid excretion were changed in CETP Tg compared to nTg mice. CETP Tg mice also showed enhanced hepatic cholesterol content. Steady state cholesterol homeostasis was probably preserved through the downregulation of hepatic HMG-CoA reductase and LDL receptor expression. In conclusion, although CETP expression facilitates cholesteryl ester tissue uptake, it does not alter biliary lipid and fecal bile acid excretion, the mandatory final step of the reverse cholesterol transport.

  5. Atmospheric CO2 uptake throughout bio-enhanced brucite-water reaction at Montecastelli serpentinites (Italy)

    Science.gov (United States)

    Bedini, Federica; Boschi, Chiara; Ménez, Benedicte; Perchiazzi, Natale; Zanchetta, Giovanni

    2014-05-01

    In the last several years, interactions between microorganisms and minerals have intrigued and catched the interest of the scientific community. Montecastelli serpentinites (Tuscany, Italy) are characterized by CO2-mineral carbonation, an important process which leads to spontaneous formation of carbonate phases uptaking atmospheric CO2. In the studied areas carbonate precipitates, mainly hydrated Mg-carbonates, are present in form of crusts, coating and spherules on exposed rock surfaces, and filling rock fractures. Petrographic and mineralogical observations revealed that Tuscan brucite-rich serpentinites hosts preserve their original chemical compositions with typical mesh-textured serpentine (± brucite) after olivine, magnetite-rich mesh rims and relicts of primary spinel. Representative hydrated carbonate samples have been collected in three different areas and analyzed to investigate the role of biological activity and its influence in the serpentine-hydrated Mg-carbonates reaction. The different types of whitish precipitates have been selected under binocular microscope for XRD analyses performed at the Dipartimento di Scienze della Terra (University of Pisa, Italy): their mineralogical composition consists of mainly hydromagnesite and variable amount of other metastable carbonate phases (i.e. nesquehonite, manasseite, pyroaurite, brugnatellite and aragonite). Moreover, the crystallinity analysis of whitish crust and spherules have been carried out by detailed and quantitative XRD analyses to testify a possible biologically controlled growth, inasmuch as the crystal structure of biominerals could be affected by many lattice defects (i.e. dislocations, twinning, etc.) and this observation cause low crystallinity of the mineral. The presence of microbial cells and relicts of organic matter has already been detected by confocal laser scanning microscopy (CLSM) combined with Raman spectromicroscopy in a previous study (Bedini et al., 2013). The presence of

  6. Engineering of Nitrosomonas europaea to express Vitreoscilla hemoglobin enhances oxygen uptake and conversion of ammonia to nitrite.

    Science.gov (United States)

    Kunkel, Stephanie A; Pagilla, Krishna R; Stark, Benjamin C

    2015-12-01

    Nitrosomonas europaea was transformed with a recombinant plasmid bearing the gene (vgb) encoding the hemoglobin (VHb) from the bacterium Vitreoscilla under control of the N. europaea amoC P1 promoter. Vgb was maintained stably and appeared to be expressed in the transformants at VHb levels of about 0.75 nmol/g wet weight. Expression of VHb in the N. europaea transformants was correlated with an approximately 2 fold increase in oxygen uptake rate by whole cells at oxygen concentrations in the range of 75-100% saturation, but no change in oxygen uptake rate at oxygen concentrations below 25% saturation. VHb expression was also correlated with an increase of as much as about 30% in conversion of ammonia to nitrite by growing cells. The results suggest that engineering of key aerobic wastewater bacteria to express bacterial hemoglobins may be a useful strategy to produce species with enhanced respiratory abilities.

  7. Multifunctional non-viral gene vectors with enhanced stability, improved cellular and nuclear uptake capability, and increased transfection efficiency

    Science.gov (United States)

    Yang, Zhe; Jiang, Zhaozhong; Cao, Zhong; Zhang, Chao; Gao, Di; Luo, Xingen; Zhang, Xiaofang; Luo, Huiyan; Jiang, Qing; Liu, Jie

    2014-08-01

    We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell for nanoparticle stabilization, poly(γ-glutamic acid) (γ-PGA) and mTAT (a cell-penetrating peptide) for accelerated cellular uptake, and a nuclear localization signal peptide (NLS) for enhanced intracellular transport of DNA to the nucleus. In vitro study showed that coating of the binary PPMS/DNA polyplex with γ-PGA promotes cellular uptake of the polyplex particles, particularly by γ-glutamyl transpeptidase (GGT)-positive cells through the GGT-mediated endocytosis pathway. Conjugating PEG to the γ-PGA led to the formation of a ternary PPMS/DNA/PGA-g-PEG polyplex with decreased positive charges on the surface of the polyplex particles and substantially higher stability in serum-containing aqueous medium. The cellular uptake rate was further improved by incorporating mTAT into the ternary polyplex system. Addition of the NLS peptide was designed to facilitate intracellular delivery of the plasmid to the nucleus--a rate-limiting step in the gene transfection process. As a result, compared with the binary PPMS/LucDNA polyplex, the new mTAT-quaternary PPMS/LucDNA/NLS/PGA-g-PEG-mTAT system exhibited reduced cytotoxicity, remarkably faster cellular uptake rate, and enhanced transport of DNA to the nucleus. All these advantageous functionalities contribute to the remarkable gene transfection efficiency of the mTAT-quaternary polyplex both in vitro and in vivo, which exceeds that of the binary polyplex and commercial Lipofectamine™ 2000/DNA lipoplex. The multifunctional mTAT-quaternary polyplex system with improved efficiency and reduced cytotoxicity represents a new type of promising non-viral vectors for the delivery of therapeutic genes to treat tumors.We have developed a new multifunctional, non-viral gene delivery platform consisting of cationic poly(amine-co-ester) (PPMS) for DNA condensation, PEG shell

  8. Mutation Study of Two Thymidine Kinases 

    DEFF Research Database (Denmark)

    Skovgaard, Tine; Munch-Petersen, Birgitte; Eklund, Hans

    The deoxyribonucleoside kinase, thymidine kinase 1 (TK1), is a key enzyme in the salvage pathway, where it catalyzes the first of three phosphate transfers from ATP to thymidine. Besides from their importance in DNA metabolism deoxyribonucleoside kinases are also important for activation of antic...... not phosphorylate the anticancer analog 1-β-D-arabinofuranosylcytosine (AraC), however. The HuTK1 mutant has been crystallized, and azidothymidine monophosphate has been modelled into the active site.......The deoxyribonucleoside kinase, thymidine kinase 1 (TK1), is a key enzyme in the salvage pathway, where it catalyzes the first of three phosphate transfers from ATP to thymidine. Besides from their importance in DNA metabolism deoxyribonucleoside kinases are also important for activation...... of anticancer and antiviral nucleoside pro-drugs. Humans have four different deoxyribonucleoside kinases, the two cytosolic: TK1 and deoxycytidine kinase (dCK) and the two mitochondrial: thymidine kinase 2 (TK2) and deoxyguanosine kinase (dGK). In insects, a single gene encodes a multi substrate kinase...

  9. Does increased zinc uptake enhance grain zinc mass concentration in rice?

    NARCIS (Netherlands)

    Jiang, W.; Struik, P.C.; Keulen, van H.; Zhao, M.; Jin, L.N.; Stomph, T.J.

    2008-01-01

    Rice (Oryza sativa) is the worlds' most important cereal and potentially an important source of zinc (Zn) for people who eat mainly rice. To improve Zn delivery by rice, plant Zn uptake and internal allocation need to be better understood. This study reports on within-plant allocation and potential

  10. Preparation and Characterization of Mucoadhesive Nanoparticles for Enhancing Cellular Uptake of Coenzyme Q10.

    Science.gov (United States)

    Lee, Ji-Soo; Suh, Ji Woon; Kim, Eun Suh; Lee, Hyeon Gyu

    2017-10-11

    The mucoadhesive nanoparticles (NPs) for oral delivery of coenzyme Q10 (CoQ10) were prepared using natural mucoadhesive polysaccharides, chitosan (CS), and dextran sulfate sodium salt (DS) in order to improve the solubility, cellular uptake, and thermo- and photostability of CoQ10. CoQ10-loaded NPs were prepared in the range of 340-450 nm with an entrapment efficiency of 60-98%. The mucoadhesiveness and cellular uptake of NPs were evaluated by measuring the amount of mucin adsorbed on NPs and CoQ10 absorbed in Caco-2 cells, respectively. CS/DS NPs had higher mucoadhesive strength than CS/sodium triphosphate pentabasic NPs (control group). Moreover, the solubility, cellular uptake, thermo- and photostability of CS/DS NPs were significantly improved compared with non-nanoencapsulated free CoQ10. Particularly, CS/DS NPs prepared with 0.5 mg/mL of CS and DS produced the highest mucoadhesiveness, solubility, cellular uptake, and cellular antioxidant activity. Thus, mucoadhesive CS/DS NPs may be an effective oral delivery platform for improving bioavailability of CoQ10.

  11. Laser-induced thermal coagulation enhances skin uptake of topically applied compounds

    DEFF Research Database (Denmark)

    Haak, C S; Hannibal, J; Paasch, U

    2017-01-01

    BACKGROUND: Ablative fractional laser (AFL) generates microchannels in skin surrounded by a zone of thermally altered tissue, termed the coagulation zone (CZ). The thickness of CZ varies according to applied wavelength and laser settings. It is well-known that AFL channels facilitate uptake...

  12. Enhanced uptake and photoactivation of topical methyl aminolevulinate after fractional CO2 laser pretreatment

    DEFF Research Database (Denmark)

    Haedersdal, M; Katsnelson, J; Sakamoto, F H

    2011-01-01

    Photodynamic therapy (PDT) of thick skin lesions is limited by topical drug uptake. Ablative fractional resurfacing (AFR) creates vertical channels that may facilitate topical PDT drug penetration and improve PDT-response in deep skin layers. The purpose of this study was to evaluate whether pre...

  13. Binding proteins enhance specific uptake rate by increasing the substrate-transporter encounter rate.

    NARCIS (Netherlands)

    Bosdriesz, E.; Magnúsdóttir, S.; Bruggeman, F.J.; Teusink, B.; Molenaar, D.

    2015-01-01

    Microorganisms rely on binding-protein assisted, active transport systems to scavenge for scarce nutrients. Several advantages of using binding proteins in such uptake systems have been proposed. However, a systematic, rigorous and quantitative analysis of the function of binding proteins is

  14. Fermented milk, Kefram-Kefir enhances glucose uptake into insulin-responsive muscle cells.

    Science.gov (United States)

    Teruya, Kiichiro; Yamashita, Maiko; Tominaga, Rumi; Nagira, Tsutomu; Shim, Sun-Yup; Katakura, Yoshinori; Tokumaru, Sennosuke; Tokumaru, Koichiro; Barnes, David; Shirahata, Sanetaka

    2002-11-01

    Diminution of insulin-responses in the target organ is the primary cause of non-insulin dependent diabetes mellitus (NIDDM).It is thought to be correlated to the excessive production of reactive oxygen species (ROS). In this article, we attempted to evaluate whether fermented milk, Kefram-Kefir known as an antioxidant, reduces the cellular ROS levels and can stimulate the glucose uptake in L6 skeletal muscle cells. Water-soluble or chloroform/methanol-extracted fractions from Kefram-Kefir were examined to evaluate the glucose uptake ability of L6 myotubes.As a result, the water-soluble fraction augmented the uptake of glucose in L6 myotubes both in the presence and absence of insulin stimulation. Estimation of intracellular ROS level revealed that the water-soluble fraction of Kefram-Kefir reduced the intracellular ROS level on both the undifferentiated and differentiated L6 cells. Especially, glucose uptake was augmented up to six times with the addition of water-soluble fraction in the insulin-stimulated L6 myotubes. Glucose transport determination revealed that the active agent in Kefram-Kefir was resistant to autoclave and stable in pH range from 4 to 10, and the small molecule below the molecular weight of 1000. Furthermore, this augmentation was inhibited in the presence of phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor wortmannin. Considering together with the reports that PI 3-kinase is locatedin the insulin signaling pathway and the participation in the translocation of glucose transporter 4 to the cell membrane, it is suggested that the water-soluble fraction of Kefram-Kefir activates PI 3-kinase or other upstream molecules in the insulin signaling pathway, which resulted in the augmentation of glucose uptake and its specific inhibition by wortmannin.

  15. Hexavalent chromium stress enhances the uptake of nitrate but reduces the uptake of ammonium and glycine in pak choi (Brassica chinensis L.).

    Science.gov (United States)

    Ma, Qingxu; Cao, Xiaochuang; Ma, Jinzhao; Tan, Xiaoli; Xie, Yinan; Xiao, Han; Wu, Lianghuan

    2017-05-01

    Chromium (Cr) pollution affects plant growth and biochemical processes, so, the relative uptake of glycine, nitrate, and ammonium by pak choi (Brassica chinensis) seedlings in treatments with 0mgL(-1) and 10mgL(-1) Cr (VI) were detected by substrate-specific (15)N-labelling in a sterile environment. The short-term uptake of (15)N-labelled sources and (15)N-enriched amino acids were detected by gas chromatography mass spectrometry to explore the mechanism by which Cr stress affects glycine uptake and metabolism, which showing that Cr stress hindered the uptake of ammonium and glycine but increased significantly the uptake of nitrate. Cr stress did not decrease the active or passive uptake of glycine, but it inhibited the conversion of glycine to serine in pak choi roots, indicating that the metabolism of glycine to serine in roots, rather than the root uptake, was the limiting step in glycine contribution to total N uptake in pak choi. Since Cr affects the relative uptake of different N sources, a feasible way to reduce Cr-induced stress is application of selective fertilization, in particular nitrate, in pak choi cultivation on Cr-polluted soil. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Pasteurella multocida thymidine kinase 1 efficiently activates pyrimidine nucleoside analogs.

    Science.gov (United States)

    Clausen, A R; Al Meani, S A L; Piskur, J

    2010-06-01

    In the Pasteurella multocida genome only one putative deoxyribonucleoside kinase encoding gene, for thymidine kinase 1 (PmTK1), was identified. The PmTK1 gene was sub-cloned into Escherichia coli KY895 and it sensitized the host towards 2',2'-difluoro-deoxycytidine (gemcitabine, dFdC), 3'-azido-thymidine (AZT) and 5-fluoro-deoxyuridine (5F-dU). PmTK1 was over-expressed and purified with two different tags. Apparently, deoxyuridine (dU), and not thymidine (dT), is the preferred substrate. We suggest that PmTK1s could be employed as a species-specific activator of uracil-based nucleoside antibiotics.

  17. Synergic regulation of redox potential and oxygen uptake to enhance production of coenzyme Q10 in Rhodobacter sphaeroides.

    Science.gov (United States)

    Zhu, Yongqiang; Ye, Lidan; Chen, Zhaofeng; Hu, Weijiang; Shi, Yanghui; Chen, Jianbo; Wang, Chenfei; Li, Yong; Li, Weifeng; Yu, Hongwei

    2017-06-01

    The physiological role of Coenzyme Q10 (CoQ10) as an electron carrier suggests its association with redox potential. Overexpression of glyceraldehyde-3-phosphate dehydrogenase type I (gapA-1) in Rhodobacter sphaeroides elevated the NADH/NAD+ ratio and meanwhile enhanced the CoQ10 content by 58%, but at the sacrifice of biomass. On the other hand, Vitreoscilla hemoglobin was heterologously expressed to enhance the oxygen uptake ability of the cells, leading to 127% improvement of biomass. Subsequent coexpression of gapA-1 and vgb resulted in a CoQ10 titer of 83.24mg/L, representing 71% improvement as compared to the control strain RspMCS. When gapA-1 and vgb genes were co-expressed in a previously created strain RspMQd [1], 163.5mg/L of CoQ10 was produced. Finally, 600mg/L of CoQ10 production was achieved in fed-batch fermentation. These results demonstrated the synergic effect of redox potential regulation and oxygen uptake improvement on enhancing CoQ10 production in R. sphaeroides. Copyright © 2017. Published by Elsevier Inc.

  18. Stepwise pH-responsive nanoparticles for enhanced cellular uptake and on-demand intracellular release of doxorubicin.

    Science.gov (United States)

    Chen, Wei-Liang; Li, Fang; Tang, Yan; Yang, Shu-di; Li, Ji-Zhao; Yuan, Zhi-Qiang; Liu, Yang; Zhou, Xiao-Feng; Liu, Chun; Zhang, Xue-Nong

    2017-01-01

    Physicochemical properties, including particle size, zeta potential, and drug release behavior, affect targeting efficiency, cellular uptake, and antitumor effect of nanocarriers in a formulated drug-delivery system. In this study, a novel stepwise pH-responsive nanodrug delivery system was developed to efficiently deliver and significantly promote the therapeutic effect of doxorubicin (DOX). The system comprised dimethylmaleic acid-chitosan-urocanic acid and elicited stepwise responses to extracellular and intracellular pH. The nanoparticles (NPs), which possessed negative surface charge under physiological conditions and an appropriate nanosize, exhibited advantageous stability during blood circulation and enhanced accumulation in tumor sites via enhanced permeability and retention effect. The tumor cellular uptake of DOX-loaded NPs was significantly promoted by the first-step pH response, wherein surface charge reversion of NPs from negative to positive was triggered by the slightly acidic tumor extracellular environment. After internalization into tumor cells, the second-step pH response in endo/lysosome acidic environment elicited the on-demand intracellular release of DOX from NPs, thereby increasing cytotoxicity against tumor cells. Furthermore, stepwise pH-responsive NPs showed enhanced antiproliferation effect and reduced systemic side effect in vivo. Hence, the stepwise pH-responsive NPs provide a promising strategy for efficient delivery of antitumor agents.

  19. Enhanced uptake and photoactivation of topical methyl aminolevulinate after fractional CO2 laser pretreatment

    DEFF Research Database (Denmark)

    Haedersdal, M; Katsnelson, J; Sakamoto, F H

    2011-01-01

    Photodynamic therapy (PDT) of thick skin lesions is limited by topical drug uptake. Ablative fractional resurfacing (AFR) creates vertical channels that may facilitate topical PDT drug penetration and improve PDT-response in deep skin layers. The purpose of this study was to evaluate whether pre......-treating the skin with AFR before topically applied methyl aminolevulinate (MAL) could enable a deep PDT-response....

  20. Increasing the Size of the Microbial Biomass Altered Bacterial Community Structure which Enhances Plant Phosphorus Uptake

    OpenAIRE

    Pu Shen; Daniel Vaughan Murphy; George, Suman J.; Hazel Lapis-Gaza; Minggang Xu; Deirdre Bridget Gleeson

    2016-01-01

    Agricultural production can be limited by low phosphorus (P) availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C) and nitrogen (N) availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i) the addition of readily-available organic...

  1. Acylsulfonamide-Functionalized Zwitterionic Gold Nanoparticles for Enhanced Cellular Uptake at Tumor pH.

    Science.gov (United States)

    Mizuhara, Tsukasa; Saha, Krishnendu; Moyano, Daniel F; Kim, Chang Soo; Yan, Bo; Kim, Young-Kwan; Rotello, Vincent M

    2015-05-26

    A nanoparticle design featuring pH-responsive alkoxyphenyl acylsulfonamide ligands is reported herein. As a result of ligand structure, this nanoparticle is neutral at pH 7.4, becoming positively charged at tumor pH (pH range. This pH-controlled uptake and toxicity makes this particle a promising tool for tumor selective therapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Nanoscale Fluorescent Metal-Organic Framework@Microporous Organic Polymer Composites for Enhanced Intracellular Uptake and Bioimaging.

    Science.gov (United States)

    Wang, Lei; Wang, Weiqi; Zheng, Xiaohua; Li, Zhensheng; Xie, Zhigang

    2017-01-26

    Polymer-modified metal-organic frameworks combine the advantages of both soft polymers and crystalline metal-organic frameworks (MOFs). It is a big challenge to develop simple methods for surface modification of MOFs. In this work, MOF@microporous organic polymer (MOP) hybrid nanoparticles (UNP) have been synthesized by epitaxial growth of luminescent boron-dipyrromethene (BODIPYs)-imine MOPs on the surface of UiO-MOF seeds, which exhibit low cytotoxicity, smaller size distribution, well-retained pore integrity, and available functional sites. After folic acid grafting, the enhanced intracellular uptake and bioimaging was validated. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Image-guided local delivery strategies enhance therapeutic nanoparticle uptake in solid tumors.

    Science.gov (United States)

    Mouli, Samdeep K; Tyler, Patrick; McDevitt, Joseph L; Eifler, Aaron C; Guo, Yang; Nicolai, Jodi; Lewandowski, Robert J; Li, Weiguo; Procissi, Daniel; Ryu, Robert K; Wang, Y Andrew; Salem, Riad; Larson, Andrew C; Omary, Reed A

    2013-09-24

    Nanoparticles (NP) have emerged as a novel class of therapeutic agents that overcome many of the limitations of current cancer chemotherapeutics. However, a major challenge to many current NP platforms is unfavorable biodistribution, and limited tumor uptake, upon systemic delivery. Delivery, therefore, remains a critical barrier to widespread clinical adoption of NP therapeutics. To overcome these limitations, we have adapted the techniques of image-guided local drug delivery to develop nanoablation and nanoembolization. Nanoablation is a tumor ablative strategy that employs image-guided placement of electrodes into tumor tissue to electroporate tumor cells, resulting in a rapid influx of NPs that is not dependent on cellular uptake machinery or stage of the cell cycle. Nanoembolization involves the image-guided delivery of NPs and embolic agents directly into the blood supply of tumors. We describe the design and testing of our innovative local delivery strategies using doxorubicin-functionalized superparamagnetic iron oxide nanoparticles (DOX-SPIOs) in cell culture, and the N1S1 hepatoma and VX2 tumor models, imaged by high resolution 7T MRI. We demonstrate that local delivery techniques result in significantly increased intratumoral DOX-SPIO uptake, with limited off-target delivery in tumor-bearing animal models. The techniques described are versatile enough to be extended to any NP platform, targeting any solid organ malignancy that can be accessed via imaging guidance.

  4. Impact of nitrite on aerobic phosphorus uptake by poly-phosphate accumulating organisms in enhanced biological phosphorus removal sludges.

    Science.gov (United States)

    Zeng, Wei; Li, Boxiao; Yang, Yingying; Wang, Xiangdong; Li, Lei; Peng, Yongzhen

    2014-02-01

    Impact of nitrite on aerobic phosphorus (P) uptake of poly-phosphate accumulating organisms (PAOs) in three different enhanced biological phosphorus removal (EBPR) systems was investigated, i.e., the enriched PAOs culture fed with synthetic wastewater, the two lab-scale sequencing batch reactors (SBRs) treating domestic wastewater for nutrient removal through nitrite-pathway nitritation and nitrate-pathway nitrification, respectively. Fluorescence in situ hybridization results showed that PAOs in the three sludges accounted for 72, 7.6 and 6.5% of bacteria, respectively. In the enriched PAOs culture, at free nitrous acid (FNA) concentration of 0.47 × 10(-3) mg HNO₂-N/L, aerobic P-uptake and oxidation of intercellular poly-β-hydroxyalkanoates were both inhibited. Denitrifying phosphorus removal under the aerobic conditions was observed, indicating the existence of PAOs using nitrite as electron acceptor in this culture. When the FNA concentration reached 2.25 × 10(-3) mg HNO2-N/L, denitrifying phosphorus removal was also inhibited. And the inhibition ceased once nitrite was exhausted. Corresponding to both SBRs treating domestic wastewater with nitritation and nitrification pathway, nitrite inhibition on aerobic P-uptake by PAOs did not occur even though FNA concentration reached 3 × 10(-3) and 2.13 × 10(-3) mg HNO₂-N/L, respectively. Therefore, PAOs taken from different EBPR activated sludges had different tolerance to nitrite.

  5. Enhanced hepatic uptake and processing of cholesterol esters from low density lipoprotein by specific lactosaminated Fab fragments.

    Science.gov (United States)

    Bijsterbosch, M K; Bernini, F; Bakkeren, H F; Gotto, A M; Smith, L C; van Berkel, T J

    1991-01-01

    Reduction of the blood levels of low density lipoprotein (LDL) is important for lowering the incidence of atherosclerosis. In this study, LDL was directed to rat parenchymal liver cells by lactosaminated Fab fragments of anti-apolipoprotein B antibodies (LacFab). We followed the fate of intravenously injected complexes of LacFab and [3H]cholesteryl oleate-labeled LDL. Complexing of LacFab to LDL led to rapid disappearance of LDL from the circulation. At 30 minutes after injection, the liver contained 58.5 +/- 9.0% of the injected dose (at that time the liver contained only 5.7 +/- 2.2% of an injected dose of free LDL). Liver uptake was blocked by N-acetylgalactosamine but not by N-acetylglucosamine, which indicates that galactose-specific recognition sites are responsible for the LacFab-induced hepatic uptake. By isolating liver cells, it was found that parenchymal, endothelial, and Kupffer cells account for 87%, 3%, and 10% of the total hepatic uptake, respectively. Subcellular fractionation of the liver indicated that the complexes are rapidly internalized and transported to lysosomes. Within 1 hour after injection, virtually all the [3H]cholesteryl oleate of the internalized LDL was hydrolyzed; hydrolysis was followed by excretion of radioactivity into the bile. Compared with rats injected with native [3H]cholesteryl oleate-labeled LDL, eight times as much radioactivity was excreted into the bile during the first 4 hours after the injection of LacFab-complexed [3H]cholesteryl oleate-labeled LDL. Thus, LacFab induces enhanced hepatic uptake of LDL via galactose receptors on the parenchymal cells, followed by processing in lysosomes and excretion into the bile. In this way, LacFab induces an increased irreversible removal of LDL cholesterol from the body.

  6. Mycorrhiza and heavy metal resistant bacteria enhance growth, nutrient uptake and alter metabolic profile of sorghum grown in marginal soil.

    Science.gov (United States)

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2016-08-01

    The main challenge for plants growing in nutrient poor, contaminated soil is biomass reduction, nutrient deficiency and presence of heavy metals. Our aim is to overcome these challenges using different microbial combinations in mining-impacted soil and focus on their physiological and biochemical impacts on a model plant system, which has multiple applications. In the current study, sorghum BTx623 seedlings grown in mining-impacted soil in greenhouse were subjected to plant growth promoting bacteria (PGPB or B) alone, PGPB with arbuscular mycorrhizal fungi (My), My alone and control group with no treatment. Root biomass and uptake of most of the elements showed significant increase in all treatment groups in comparison with control. Mycorrhiza group showed the best effect followed by My + B and B groups for uptake of majority of the elements by roots. On the contrary, biomass of both shoot and root was more influenced by B treatment than My + B and My treatments. Metabolomics identified compounds whose levels changed in roots of treatment groups significantly in comparison to control. Upregulation of stearic acid, sorbitol, sebacic acid and ferulic acid correlated positively with biomass and uptake of almost all elements. Two biochemical pathways, fatty acid biosynthesis and galactose metabolism, were regulated in all treatment groups. Three common pathways were upregulated only in My and My + B groups. Our results suggest that PGPB enhanced metabolic activities which resulted in increase in element uptake and sorghum root biomass whether accompanied with mycorrhiza or used solely. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging: Implications for CT dosimetry.

    Science.gov (United States)

    Perisinakis, Kostas; Tzedakis, Antonis; Spanakis, Kostas; Papadakis, Antonios E; Hatzidakis, Adam; Damilakis, John

    2018-01-01

    To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry. The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging. The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake. Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure. • Radiation absorption ability of organs/tissues is considerably affected by iodine uptake • Iodinated organ/tissues may absorb up to 100 % higher radiation dose • Compared to non-enhanced, contrast-enhanced CT may deliver higher dose to patient tissues • CT dosimetry of contrast-enhanced CT imaging should encounter tissue iodine uptake.

  8. Point mutations at the thymidine kinase locus in L5178Y mouse lymphoma cells. II. Test validation and interpretation.

    Science.gov (United States)

    Amacher, D E; Paillet, S C; Turner, G N; Ray, V A; Salsburg, D S

    1980-08-01

    The L5178Y Mouse Lymphoma TK assay was studied extensively to determine if this mammalian cell assay for gene mutations at the thymidine kinase (TK) locus could provide valid, interpretable determinations of mutagenic potential, and whether this information is of value in the safety evaluation of chemicals. We first determined that test-derived TFTR mutants were phenotypically stable, possessing little or no thymidine kinase activity as measured by labeled thymidine uptake, but demonstrating 100% cross resistance to bromodeoxyuridine. Common solvent vehicles such as acetone, dimethylsulfoxide and ethanol were shown to produce little cytotoxicity and no mutagenic activity when present at 1% levels. Out of a total of 10 noncarcinogens tested, all were negative when results were analyzed by a 2-sample loge t test on control and treated mutant count means. Of the 13 putative animal carcinogens tested, 10 were positive, 2 were negative (auramine O and sodium phenobarbital), and 1 showed sporadic activity (hydrazine sulfate) in the TK assay on the basis of test-derived t statistics. 2 compounds, 1,2-epoxybutane and ICR 191, which have been described as Ames positive non-carcinogens, were also positive in the TK assay. Although this sampling of a total of 29 compounds is insufficient for precise estimations of expected false-positive or false-negative frequencies, these data indicate the TK assay can be expected to detect a majority of carcinogens as mutagens including some missed by more established point-mutation assays.

  9. Tomato thymidine kinase is subject to inefficient TTP feedback regulation

    DEFF Research Database (Denmark)

    Larsen, Nicolai Balle; Munch-Petersen, Birgitte; Piskur, Jure

    2014-01-01

    A promising suicide gene therapy system to treat gliomas has been reported: the thymidine kinase 1 from tomato (toTK1) combined with the nucleoside analog pro-drug zidovudine (azidothymidine, AZT), which is known to penetrate the blood–brain barrier. Transduction with toTK1 has been found...

  10. Comparison of Physical Pretreatment Regimens to Enhance Protoporphyrin IX Uptake in Photodynamic Therapy

    DEFF Research Database (Denmark)

    Bay, Christiane; Lerche, Catharina Margrethe; Ferrick, Bradford

    2017-01-01

    Importance: Skin pretreatment is recommended for adequate penetration of topical photosensitizing agents and subsequent protoporphyrin IX (PPIX) accumulation in photodynamic therapy (PDT). Objective: To compare the relative potential of different physical pretreatments to enhance PPIX fluorescence...... indicate relatively enhanced PDT response by AFXL pretreatment in diseased skin. Trial Registration: clinicaltrials.gov Identifier: NCT02372370....

  11. Coumarin enhances nitrate uptake in maize roots throughout a modulation of plasma membrane H+ -ATPase activity.

    Science.gov (United States)

    Lupini, Antonio; Araniti, Fabrizio; Mauceri, Antonio; Princi, Maria Polsia; Sorgonà, Agostino; Sunseri, Francesco; Varanini, Zeno; Abenavoli, Maria Rosa

    2017-11-27

    1.Coumarin is one of the simplest plant secondary metabolite widely distributed in plant kingdom affecting root form and function, including anatomy, morphology and nutrient uptake. Although, some plant responses to coumarin have been described, comprehensive knowledge of the physiological and molecular mechanisms is lacking. 2.Maize seedlings exposed to different coumarin concentrations, alone or in combination with 200 μM nitrate (NO3- ), were analyzed, through a physiological and molecular approach, to elucidate action of coumarin on net NO3- uptake rate (NNUR). In detail, the time course of NNUR, plasma membrane (PM) H+ -ATPase activity, the proton pumping, and related gene expressions (ZmNPF6.3, ZmNRT2.1, ZmNAR2.1, ZmHA3 and ZmHA4) were evaluated. 3.Coumarin alone did not affect nitrate uptake, the PM H+ -ATPase activity as well as the transcript levels of ZmNRT2.1 and ZmHA3. By contrast, coumarin alone increased ZmNPF6.3, ZmNAR2.1 and ZmHA4 expression, as observed in response to abiotic stress. When coumarin and NO3- were concurrently added to the nutrient solution, a significant increase in the NNUR, PM H+ -ATPase activity together with ZmNAR2.1:ZmNRT2.1 and ZmHA4 expressions were observed, suggesting that coumarin affected the inducible component of high affinity transport system (iHATS), and this effect appeared to be mediated by nitrate. Moreover, the results with vanadate, an inhibitor of the PM H+ -ATPase, suggested that this enzyme could be a main target of coumarin. 4.Surprisingly, coumarin did not affect the PM H+ -ATPase activity by direct contact with plasma membrane vesicle isolated from maize roots, indicating its possible elicitor role in the gene transcription. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Vaccination of adolescents with chronic medical conditions: Special considerations and strategies for enhancing uptake

    Science.gov (United States)

    Hofstetter, Annika M; LaRussa, Philip; Rosenthal, Susan L

    2015-01-01

    Adolescents with chronic medical conditions (CMCs), a growing population worldwide, possess a wide array of preventive health care needs. Vaccination is strongly recommended for the vast majority of these adolescents given their increased risk of vaccine preventable infection and associated complications. Not only should they receive routine vaccines, but some also require additional vaccines. Despite these guidelines, evidence suggests that adolescents with CMCs often fail to receive needed vaccines. Many factors contribute to this under-immunization, including lack of knowledge among parents and providers and suboptimal coordination of primary and subspecialty care. This review describes current vaccination recommendations for these adolescents as well as recent data related to infection risk, vaccine efficacy and safety, vaccination coverage, and the unique multilevel factors impacting uptake in this population. It also discusses strategies for improving coverage levels and reducing missed vaccination opportunities, with a particular focus on technology-based interventions. PMID:26212313

  13. Carboxymethyl Cellulose-Grafted Mesoporous Silica Hybrid Nanogels for Enhanced Cellular Uptake and Release of Curcumin

    Directory of Open Access Journals (Sweden)

    Neha Tiwari

    2017-02-01

    Full Text Available Mesoporous silica nanoparticles (MSNs with ordered pore structure have been synthesized and used as carriers for the anticancer drug curcumin. MSNs were functionalized with amine groups and further attached with carboxymethyl cellulose (CMC using 1-ethyl-3-(3-dimethylaminopropyl-carbodiimide (EDC coupling chemistry, which increased the hydrophilicity and biocompatibility of MSNs. The functionalized MSNs (MSN-NH2 and MSN-CMC were characterized using Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM, Dynamic Light Scattering (DLS, N2 adsorption, X-Ray Diffraction (XRD, Thermo Gravimetric Analysis (TGA and Fourier Transform Infrared Spectroscopy (FT-IR. The in vitro release of curcumin from the –NH2 and CMC functionalized MSNs (MSN-cur-NH2 and MSN-cur-CMC was performed in 0.5% aqueous solution of sodium lauryl sulphate (SLS. The effect of CMC functionalization of MSNs towards cellular uptake was studied in the human breast cancer cell line MDA-MB-231 and was compared with that of MSN-NH2 and free curcumin (cur. Both MSN-NH2 and MSN-CMC showed good biocompatibility with the breast cancer cell line. The MTT assay study revealed that curcumin-loaded MSN-cur-CMC showed better uptake as compared to curcumin-loaded MSN-cur-NH2. Free curcumin was used as a control and was shown to have much less internalization as compared to the curcumin-loaded functionalized MSNs due to poor bioavailability. Fluorescence microscopy was used to localize the fluorescent drug curcumin inside the cells. The work demonstrates that CMC-functionalized MSNs can be used as potential carriers for loading and release of hydrophobic drugs that otherwise cannot be used effectively in their free form for cancer therapy.

  14. Enhanced terrestrial carbon uptake linked to a recent pause in the growth rate of atmospheric CO2

    Science.gov (United States)

    Keenan, T. F.; Prentice, I. C. C.; Canadell, J.; Williams, C. A.; Wang, H.; Collatz, G. J.

    2016-12-01

    The terrestrial carbon sink is increasing, yet the mechanisms responsible for its long-term enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here, using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple process-based global vegetation models, we examine the causes and consequences of the enhancement of the terrestrial carbon sink. We show that over the past century the enhanced sink is largely due to the effect of elevated CO2 on photosynthesis dominating over warming induced increases in respiration. The slowdown in global warming since the start of the 21st century is shown to have increased the sink, leading to a pause in the growth rate of atmospheric CO2, and providing further evidence of the relative roles of CO2 fertilization and warming induced respiration. The effect of enhanced terrestrial carbon uptake on the atmospheric CO2 growth rate highlights the need to protect both existing carbon stocks and those areas where the sink is growing most rapidly.

  15. Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones have enhanced activity under high glucose conditions

    Directory of Open Access Journals (Sweden)

    de Dios Stephanie T

    2007-10-01

    Full Text Available Abstract Background Inhibition of vascular smooth muscle cell (vSMC proliferation by oral anti-hyperglycemic agents may have a role to play in the amelioration of vascular disease in diabetes. Thiazolidinediones (TZDs inhibit vSMC proliferation but it has been reported that they anomalously stimulate [3H]-thymidine incorporation. We investigated three TZDs, two biguanides and two sulfonylureas for their ability of inhibit vSMC proliferation. People with diabetes obviously have fluctuating blood glucose levels thus we determined the effect of media glucose concentration on the inhibitory activity of TZDs in a vSMC preparation that grew considerably more rapidly under high glucose conditions. We further explored the mechanisms by which TZDs increase [3H]-thymidine incorporation. Methods VSMC proliferation was investigated by [3H]-thymidine incorporation into DNA and cell counting. Activation and inhibition of thymidine kinase utilized short term [3H]-thymidine uptake. Cell cycle events were analyzed by FACS. Results VSMC cells grown for 3 days in DMEM with 5% fetal calf serum under low (5 mM glucose and high (25 mM glucose increased in number by 2.5 and 4.7 fold, respectively. Rosiglitazone and pioglitazone showed modest but statistically significantly greater inhibitory activity under high versus low glucose conditions (P 3H]-thymidine into DNA but did not increase cell numbers. Troglitazone inhibited serum mediated thymidine kinase induction in a concentration dependent manner. FACS analysis showed that troglitazone and rosiglitazone but not pioglitazone placed a slightly higher percentage of cells in the S phase of a growing culture. Of the biguanides, metformin had no effect on proliferation assessed as [3H]-thymidine incorporation or cell numbers whereas phenformin was inhibitory in both assays albeit at high concentrations. The sulfonylureas chlorpropamide and gliclazide had no inhibitory effect on vSMC proliferation assessed by either [3H]-thymidine

  16. Silicon-enhanced resistance to cadmium toxicity in Brassica chinensis L. is attributed to Si-suppressed cadmium uptake and transport and Si-enhanced antioxidant defense capacity

    Energy Technology Data Exchange (ETDEWEB)

    Song Alin [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Zhaojun [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang Jie [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Xue Gaofeng; Fan Fenliang [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Liang Yongchao, E-mail: ycliang@caas.ac.cn [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi 832003 (China)

    2009-12-15

    A series of hydroponics experiments were performed to investigate roles of silicon (Si) in enhancing cadmium (Cd) tolerance in two pakchoi (Brassica chinensis L.) cultivars: i.e. cv. Shanghaiqing, a Cd-sensitive cultivar, and cv. Hangyoudong, a Cd-tolerant cultivar. Plants were grown under 0.5 and 5 mg Cd L{sup -1} Cd stress without or with 1.5 mM Si. Plant growth of the Cd-tolerant cultivar was stimulated at the lower Cd level, but was decreased at the higher Cd level when plants were treated with Cd for one week. However, Plant growth was severely inhibited at both Cd levels as stress duration lasted for up to three weeks. Plant growth of the Cd-sensitive cultivar was severely inhibited at both Cd levels irrespective of Cd stress duration. Addition of Si increased shoot and root biomass of both cultivars at both Cd levels and decreased Cd uptake and root-to-shoot transport. Superoxide dismutase, catalase and ascorbate peroxidase activities decreased, but malondialdehyde and H{sub 2}O{sub 2} concentrations increased at the higher Cd level, which were counteracted by Si added. Ascorbic acid, glutathione and non-protein thiols concentrations increased at the higher Cd level, which were further intensified by addition of Si. The effects of Si and Cd on the antioxidant enzyme activity were further verified by isoenzyme analysis. Silicon was more effective in enhancing Cd tolerance in the Cd-tolerant cultivar than in the Cd-sensitive cultivar. It can be concluded that Si-enhanced Cd tolerance in B. chinensis is attributed mainly to Si-suppressed Cd uptake and root-to-shoot Cd transport and Si-enhanced antioxidant defense activity.

  17. Thymidine kinase 1 deficient cells show increased survival rate after UV-induced DNA damage

    DEFF Research Database (Denmark)

    Skovgaard, T; Rasmussen, Lene Juel; Munch-Petersen, Birgitte

    2010-01-01

    Balanced deoxynucleotide pools are known to be important for correct DNA repair, and deficiency for some of the central enzymes in deoxynucleotide metabolism can cause imbalanced pools, which in turn can lead to mutagenesis and cell death. Here we show that cells deficient for the thymidine salvage...... enzyme thymidine kinase 1 (TK1) are more resistant to UV-induced DNA damage than TK1 positive cells although they have thymidine triphosphate (dTTP) levels of only half the size of control cells. Our results suggest that higher thymidine levels in the TK- cells caused by defect thymidine salvage to d...

  18. Cationic micelle based vaccine induced potent humoral immune response through enhancing antigen uptake and formation of germinal center.

    Science.gov (United States)

    Luo, Zichao; Shi, Shuai; Jin, Ling; Xu, Lu; Yu, Jing; Chen, Hao; Li, Xingyi

    2015-11-01

    Nanoparticles have been proven to be an effective vaccine delivery system that can boost immune responses to subunit vaccines. Herein, we developed and characterized a cationic polymeric polyethylene glycol2000-poly ϵ-caprolactone2000-polyethylenimine2000 (mPEG2000-PCL2000-g-PEI2000) micelle as a potent vaccine delivery system to boost the immune response in vivo. The micelles that we developed exhibited great antigen-loading capability and minimal cytotoxicity in vitro. Meanwhile, micelles facilitated OVA antigen uptake by dendritic cells both in vitro and in vivo. More importantly, a micelle-formulated OVA vaccine could significantly promote anti-OVA antibody production by 190-fold and potently enhance T cell proliferation and the secretion of IL-5 and IFN-γ. We attributed these effects to its ability to promote antigen uptake, antigen deposition, and germinal center formation. In conclusion, the mPEG2000-PCL2000-PEI2000 micelle that we developed has potential as potent vaccine delivery system to induce Th2 immune response. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Preparation of pH-sensitive zwitterionic nano micelles and drug controlled release for enhancing cellular uptake.

    Science.gov (United States)

    Wu, Luyan; Ni, Caihua; Zhang, Liping; Shi, Gang

    2016-01-01

    Zwitterionic copolymers have exhibited high resistance to nonspecific protein adsorption and have wide applications in drug delivery systems. Herein, a pH-responsive poly(Lysine-alt-N,N'-bis(acryloyl) diaminohexane) was synthesized through the Michael addition polymerization between N, N'-bis(acryloyl) diaminohexane and lysine. Subsequently, nano micelles (NMs) were formed by self-assembly of the copolymer in an aqueous solution. The NMs showed a slightly negative charge in blood environment, but a positively charged surface in extracellular pH of tumor. This feature could be used to enhance permeability and retention effect, and reinforce tumor cell uptake. Vitro release studies revealed that the release of DOX from the DOX-loaded NMs was evidently faster at pH 5.0 than at pH 7.4. MTT assays revealed that NMs were nontoxic. Thus, these smart NMs were feasible candidates and could be potentially used in cancer chemotherapy.

  20. Titanium uptake, induction of RANK-L expression, and enhanced proliferation of human T-lymphocytes.

    Science.gov (United States)

    Cadosch, Dieter; Sutanto, Michael; Chan, Erwin; Mhawi, Amir; Gautschi, Oliver P; von Katterfeld, Brilliana; Simmen, Hans-Peter; Filgueira, Luis

    2010-03-01

    There is increasing evidence that titanium ions are released from orthopedic implants by biocorrosion. The aim of this study was to investigate titanium uptake by human T-lymphocytes and its effects on phenotype and proliferation. Freshly isolated human nonadherent peripheral blood mononuclear cells (NA-PBMC), were exposed to TiCl4 [Ti(IV)]. Bioavailability and distribution of Ti(IV) in T-lymphocytes was determined by energy-filtered electron microscopy (EFTEM). The effects of Ti(IV) challenge on nonactivated and PHA-activated cells were assessed by flow cytometric analysis of surface markers, RANK-L production, and proliferation assays. EFTEM colocalized Ti(IV) with phosphorus in the nucleus, ribosomes, cytoplasmic membranes, and the surface membrane of T-lymphocytes. Ti(IV) increased significantly the expression of CD69, CCR4, and RANK-L in a concentration-dependent manner. Titanium enters T-lymphocytes through a currently unknown mechanism and binds to phosphorus-rich cell structures. Titanium influences phenotype and function of T-lymphocytes, resulting in activation of a CD69+ and CCR4+ T-lymphocyte population and secretion of RANK-L. These results strongly suggest the involvement of titanium ions challenged T-lymphocytes in the complex pathophysiological mechanisms of aseptic loosening of orthopedic implants.

  1. Enhanced, sialoadhesin-dependent uptake of Guillain-Barre syndrome-associated Campylobacter jejuni strains by human macrophages.

    Science.gov (United States)

    Heikema, Astrid P; Koning, Roman I; Duarte dos Santos Rico, Sharon; Rempel, Hans; Jacobs, Bart C; Endtz, Hubert P; van Wamel, Willem J B; Samsom, Janneke N

    2013-06-01

    Molecular mimicry between Campylobacter jejuni sialylated lipooligosaccharides (LOS) and human nerve gangliosides can trigger the production of cross-reactive antibodies which induce Guillain-Barré syndrome (GBS). To better understand the immune events leading to GBS, it is essential to know how sialylated LOS are recognized by the immune system. Here, we show that GBS-associated C. jejuni strains bind to human sialoadhesin (hSn), a conserved, mainly macrophage-restricted I-type lectin. Using hSn-transduced THP-1 cells, we observed that C. jejuni strains with α(2,3)-sialylated LOS, including strains expressing GM1a- and GD1a-like epitopes, bind to hSn. This observation is of importance, as these epitopes are frequently the targets of the cross-reactive antibodies detected in GBS patients. Interestingly, the Sn binding domains were not constitutively exposed on the surface of C. jejuni. Heat inactivation and the environmental conditions which food-borne C. jejuni encounters during its passage through the intestinal tract, such as low pH and contact with bile constituents, exposed LOS and facilitated Sn binding. Sn binding enhanced bacterial uptake and increased the production of interleukin-6 (IL-6) by primary human Sn-expressing monocyte-derived macrophages compared to control conditions, where Sn was blocked using neutralizing antibodies or when nonsialylated C. jejuni was used. Sn-mediated uptake has been reported to enhance humoral immune responses. As C. jejuni strains expressing ganglioside mimics GD1a and GM1a are closely associated with GBS, Sn binding may be a determining event in the production of cross-reactive antibodies and the development of GBS.

  2. Microbial siderophores and root exudates enhanced goethite dissolution and Fe/As uptake by As-hyperaccumulator Pteris vittata.

    Science.gov (United States)

    Liu, Xue; Fu, Jing-Wei; Da Silva, Evandro; Shi, Xiao-Xia; Cao, Yue; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2017-04-01

    Arsenic (As) in soils is often adsorbed on Fe-(hydro)oxides surface, rendering them more resistant to dissolution, which is undesirable for phytoremediation of As-contaminated soils. Arsenic hyperaccumulator Pteris vittata prefers to grow in calcareous soils where available Fe and As are low. To elucidate its mechanisms of acquiring Fe and As from insoluble sources in soils, we investigated dissolution of goethite with pre-adsorbed arsenate (AsV; As-goethite) in presence of four organic ligands, including two root exudates (oxalate and phytate, dominant in P. vittata) and two microbial siderophores (PG12-siderophore and desferrioxamine B). Their presence increased As solubilization from As-goethite from 0.03 to 0.27-5.33 mg L-1 compared to the control. The siderophore/phytate bi-ligand treatment released 7.42 mg L-1 soluble Fe, which was 1.2-fold that of the sum of siderophore and phytate, showing a synergy in promoting As-goethite dissolution. In the ligand-mineral-plant system, siderophore/phytate was most effective in releasing As and Fe from As-goethite. Moreover, the continuous plant uptake induced more As-goethite dissolution. The continued release of As and Fe significantly enhanced their plant uptake (from 0.01 to 0.43 mg plant-1 As and 2.7-14.8 mg plant-1 Fe) and plant growth (from 1.2 to 3.1 g plant-1 fw) in P. vittata. Since microbial siderophores and root exudates often coexist in soil rhizosphere, their synergy in enhancing dissolution of insoluble As-Fe minerals may play an important role in efficient phytoremediation of As-contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The fine-tuning of thermosensitive and degradable polymer micelles for enhancing intracellular uptake and drug release in tumors.

    Science.gov (United States)

    Li, Wei; Li, Jinfeng; Gao, Jie; Li, Bohua; Xia, Yu; Meng, Yanchun; Yu, Yongsheng; Chen, Huaiwen; Dai, Jianxin; Wang, Hao; Guo, Yajun

    2011-05-01

    Focusing on high temperature and low pH of tumor tissue, we prepared temperature and pH responsive poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide-b-lacitde) (PID(118)-b-PLA(59)) and poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide-b-ε-caprolactone) (PID(118)-b-PCL(60)) diblock copolymers with symmetric hydrophobic blocks by the reversible addition-fragmentation chain transfer (RAFT). The corresponding dual functional polymeric micelles were fabricated by dialysis methods. Their well-defined core-shell structure was characterized by (1)H NMR in D(2)O and further confirmed by TEM. Their structural and physical chemistry properties such as diameters (D), core corona dimension (R(core), R(shell)), distribution (PDI), M(w), aggregation number (N(agg)), second virial coefficient (A(2)), critical micellization concentration (CMC) and z-potential were firstly systemically investigated by dynamic and static laser light scattering. The volume phase transition temperature (VPTT) was around 40 °C above which the intracellular uptake of adriamycin (ADR) was significantly enhanced. Both flow cytometry and fluorescent microscopy showed that the ADR transported by these micelles was about 4 times higher than that by the commercial ADR formulation Taxotere®. In vitro cytotoxicity assay against N-87 cancer cell and confocal laser scanning microscopy (CLSM) also confirmed such promoting efficiency. In addition, it was interesting to find that cell surviving bounced back as T = 42 °C due to the inter-micellar aggregation. The well clarified mechanism strongly support that our finely tailored dual functional core-shell micelles are potent in enhancing cellular uptake and drug release. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Enhanced cellular uptake and cytotoxicity studies of organometallic bioconjugates of the NLS peptide in Hep G2 cells.

    Science.gov (United States)

    Noor, Fozia; Kinscherf, Ralf; Bonaterra, Gabriel A; Walczak, Steffen; Wölfl, Stefan; Metzler-Nolte, Nils

    2009-02-13

    SPACE INVADERS: Organometallic fragments such as the ferrocenyl group (shown in red in the picture) help to enhance cellular entry of NLS peptides. Eventually, these nontoxic conjugates find their way to the cellular nucleus as shown by fluorescence microscopy studies in this work. Intracellular delivery to biomolecular targets is still a major challenge in molecular and cell biology. We recently found that attaching an organometallic group, namely the cobaltocenium cation, to the SV 40 large T antigen nuclear localisation signal (NLS) greatly enhances cellular uptake of the conjugate (Noor et al., Angew. Chem. Int. Ed. 2005, 45, 2429). In addition, nuclear localisation of the conjugate was observed. In this work, we present a thorough investigation of this novel cellular delivery system with respect to the nature of the metal complex and the peptide sequence. A number of ferrocene ((Fe(II)), neutral metal complex) and cobaltocenium ((Co(III)), cationic metal complex) bioconjugates with both the NLS wild-type sequence PKKKRKV and a scrambled sequence (NLS(scr), KKVKPKR) were prepared by solid-phase peptide synthesis (SPPS). Cellular and nuclear uptake of these bioconjugates was studied by fluorescence microscopy on living Hep G2 cells. In addition, cytotoxicity screening on the conjugates was carried out, as the toxic effects of several simple metallocenes have been noted previously. Rapid cellular uptake as well as nuclear localisation was observed for the metal-NLS conjugates, but not for any dipeptide controls, the metal-NLS(scr) conjugates or any metal-free conjugates. It thus appears that the presence of a metallocene, but not its charge, and the correct NLS sequence is essential for cellular uptake. Fluorescence microscopy co-localisation studies did not reveal a significant endosomal entrapment of the conjugates. The metallocene not only provides a hydrophobic handle for membrane translocation but also facilitates the localisation and distribution of the

  5. A mathematical model of human thymidine kinase 2 activity

    DEFF Research Database (Denmark)

    Radivoyevitch, Tom; Munch-Petersen, Birgitte; Wang, Liya

    2011-01-01

    _ The mitochondrial enzyme thymidine kinase 2 (TK2) phosphorylates deoxythymidine (dT) and deoxycytidine (dC) to form dTMP and dCMP, which in cells rapidly become the negative-feedback end-products dTTP and dCTP. TK2 kinetic activity exhibits Hill coefficients of ∼0.5 (apparent negative cooperati......_ The mitochondrial enzyme thymidine kinase 2 (TK2) phosphorylates deoxythymidine (dT) and deoxycytidine (dC) to form dTMP and dCMP, which in cells rapidly become the negative-feedback end-products dTTP and dCTP. TK2 kinetic activity exhibits Hill coefficients of ∼0.5 (apparent negative...

  6. Increasing the Size of the Microbial Biomass Altered Bacterial Community Structure which Enhances Plant Phosphorus Uptake.

    Directory of Open Access Journals (Sweden)

    Pu Shen

    Full Text Available Agricultural production can be limited by low phosphorus (P availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C and nitrogen (N availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i the addition of readily-available organic substrates would increase the size of the microbial biomass thus exhausting the pool of easily-available P and (ii this would cause the microbial biomass to access P from more recalcitrant pools. In this model it is hypothesised that the size of the microbial population is regulating access to less available P rather than the diversity of organisms contained within this biomass. To test this hypothesis we added mixtures of simple organic compounds that reflect typical root exudates at different C:N ratios to a soil microcosm experiment and assessed changes in soil P pools, microbial biomass and bacterial diversity measures. We report that low C:N ratio (C:N = 12.5:1 artificial root exudates increased the size of the microbial biomass while high C:N ratio (C:N = 50:1 artificial root exudates did not result in a similar increase in microbial biomass. Interestingly, addition of the root exudates did not alter bacterial diversity (measured via univariate diversity indices but did alter bacterial community structure. Where C, N and P supply was sufficient to support plant growth the increase observed in microbial biomass occurred with a concurrent increase in plant yield.

  7. Increasing the Size of the Microbial Biomass Altered Bacterial Community Structure which Enhances Plant Phosphorus Uptake.

    Science.gov (United States)

    Shen, Pu; Murphy, Daniel Vaughan; George, Suman J; Lapis-Gaza, Hazel; Xu, Minggang; Gleeson, Deirdre Bridget

    2016-01-01

    Agricultural production can be limited by low phosphorus (P) availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C) and nitrogen (N) availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i) the addition of readily-available organic substrates would increase the size of the microbial biomass thus exhausting the pool of easily-available P and (ii) this would cause the microbial biomass to access P from more recalcitrant pools. In this model it is hypothesised that the size of the microbial population is regulating access to less available P rather than the diversity of organisms contained within this biomass. To test this hypothesis we added mixtures of simple organic compounds that reflect typical root exudates at different C:N ratios to a soil microcosm experiment and assessed changes in soil P pools, microbial biomass and bacterial diversity measures. We report that low C:N ratio (C:N = 12.5:1) artificial root exudates increased the size of the microbial biomass while high C:N ratio (C:N = 50:1) artificial root exudates did not result in a similar increase in microbial biomass. Interestingly, addition of the root exudates did not alter bacterial diversity (measured via univariate diversity indices) but did alter bacterial community structure. Where C, N and P supply was sufficient to support plant growth the increase observed in microbial biomass occurred with a concurrent increase in plant yield.

  8. Enhancing Uranium Uptake by Amidoxime Adsorbent in Seawater: An investigation for optimum alkaline conditioning parameters

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.; Tsouris, Constantinos; Zhang, C.; Kim, J.; Brown, S.; Oyola, Yatsandra; Janke, C.; Mayes, R. T.; Kuo, Li-Jung; Wood, Jordana R.; Gill, Gary A.; Dai, Sheng

    2016-04-20

    A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory (ORNL) by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 ºC). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration of ~ 7-8 ppm and pH 8. FTIR and solid state NMR indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 ºC resulted in increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. Scanning electron microscopy showed that long conditioning times may also lead to adsorbent degradation

  9. Structures of thymidine kinase 1 of human and mycoplasma origin

    DEFF Research Database (Denmark)

    Welin, Martin; Kosinska, Urszula; Mikkelsen, Nils-Egil

    2004-01-01

    Cytosolic thymidine kinase, TK1, is a well-known cell cycle regulated enzyme of importance in nucleotide metabolism as well as an activator of antiviral and anticancer drugs as AZT. We have now determined the first structures of the TK1 family, the human and Ureaplasma urealyticum enzymes, in com...... differs fundamentally from the structures of the other deoxyribonucleoside kinases indicating a different evolutionary origin....

  10. Photoaddition of p-aminobenzoil acid to thymine and thymidine

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, A.A.; Wainschel, L.A.; Shetlar, M.D. (California Univ., San Francisco, CA (United States). School of Pharmacy)

    1992-05-01

    Several studies in the literature have shown that DNA is damaged after UV irradiation in the presence of the sunscreen agent p-aminobenzoic acid (PABA), both in vivo and in vitro. One type of damage has been shown to be the result of increased yields of pyrimidime cyclobutane dimer formation. However, it has been suggested that other types of lesions are produced as well. We have studied the photochemistry of the thymine-PABA and thymidine-PABA systems and report here the isolation and characterization of thymine-PABA and thymidine-PABA photoadducts. These products have been identified, respectively as 5-(2-amino-5-carboxyphenyl)-5,6-dihydrothymine and isomeric forms of 5-(2-amino-5-carboxyphenyl)-5,6-dihydrothymidine. The quantum yields for the formation of these ducts in deaerated aqueous solutions at pH 7.0 have been determined to be 9.5 x 10{sup -4} and 4.3 x 10{sup -3} for the thymine and thymidine based adducts respectively. A pH profile for the thymine-PABA system indicated a maximum quantum yield for adduct formation at pH 6.5, although it could be detected over the whole pH range studied (pH 3.5-11.0). (Author).

  11. Novel antibody conjugates for enhanced tumor uptake. Final report, September 1, 1992--August 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, M.

    1997-12-31

    Progress in three areas of research is summarized. These are as follows: Labeling Monoclonal antibodies (MAbs) with Tc-99m and Re-186; human melanoma tumors and specific MAbs; evaluation of biological response modifiers (BRM). The techniques of labeling MAbs (IgM, IgG, F(ab{prime}){sub 2} or F(ab{prime})) with Tc-99m was developed in the author`s laboratory in 1989 and that with Re-186 in 1992. The techniques are in daily use in the laboratory since then and are adapted to a convenient kit formulation. The metal ions are bound at MAb sulfhydryls generated by a controlled reduction of a pair of disulfide groups. At least two types of MAbs labeled with Tc-99m by this method have been administered into patients and excellent diagnostic results have been obtained. Over the past two and a half years the author has been successfully growing human melanoma tumors in athymic Balb/c nude mice. The cell LINE, WM-9, was obtained from Dr. D Herlyn`s laboratory at Wistar Institute in Philadelphia. Sufficient quantities of antihuman melanoma specific antibodies ME 31.3 (Wistar, IgG-1) and MEM-136 (Hybritech, IgG-2A) and their F(ab{prime}){sub 2} fragments are also available in the laboratory. The use of BRM is a rapidly evolving field. Over the past four years, the author has evaluated a number of BRMs in a quest for agents that may augment MAb tumor uptake. These included interferon-{alpha}; a pokeweed mitogen and Ukrain, an alkaloid separated from a plant Chelideonium Majis. In these preliminary studies, normal Balb/c mice were used and the BRMs were given i.p. one hour prior to the i.v. administration of tumor necrosis factor or an MAb (TNT-F(ab{prime}){sub 2}) labeled with Tc-99m which served as an imaging agent. Animals were sacrificed at 1.5 hr or 4 hrs post-injection. Highlights of the work are given here in a table.

  12. Citric acid enhanced the antioxidant defense system and chromium uptake by Lemna minor L. grown in hydroponics under Cr stress.

    Science.gov (United States)

    Sallah-Ud-Din, Rasham; Farid, Mujahid; Saeed, Rashid; Ali, Shafaqat; Rizwan, Muhammad; Tauqeer, Hafiz Muhammad; Bukhari, Syed Asad Hussain

    2017-07-01

    Phytoextraction is a cost-effective and eco-friendly technique for the removal of pollutants, mainly heavy metal(loids) especially from polluted water and metal-contaminated soils. The phytoextraction of heavy metals is, in general, limited due to the low availability of heavy metals in the growth medium. Organic chelators can help to improve the phytoextraction by increasing metal mobility and solubility in the growth medium. The present research was carried out to examine the possibility of citric acid (CA) in improving chromium (Cr) phytoextraction by Lemna minor (duckweed). For this purpose, healthy plants were collected from nearby marsh and grown in hydroponics under controlled conditions. Initial metal contents of both marsh water and plant were measured along with physico-chemical properties of the marsh water. Different concentrations of Cr and CA were applied in the hydroponics in different combinations after defined intervals. Continuous aeration was supplied and pH maintained at 6.5 ± 0.1. Results showed that increasing concentration of Cr significantly decreased the plant biomass, photosynthetic pigments, leaf area, and antioxidant enzyme activities (like catalase, ascorbate peroxidase, superoxide dismutase, peroxidase). Furthermore, Cr stress increased the Cr concentrations, electrolyte leakage, hydrogen peroxide, and malondialdehyde contents in plants. The addition of CA alleviated the Cr-induced toxicity in plants and further enhanced the Cr uptake and its accumulation in L. minor. The addition of CA enhanced the Cr concentration in L. minor by 6.10, 26.5, 20.5, and 20.2% at 0, 10, 100, and 200 μM Cr treatments, respectively, compared to the respective Cr treatments without CA. Overall, the results of the present study showed that CA addition may enhance the Cr accumulation and tolerance in L. minor by enhancing the plant growth and activities of antioxidant enzymes.

  13. Radiochemotherapy of hepatocarcinoma via lentivirus-mediated transfer of human sodium iodide symporter gene and herpes simplex virus thymidine kinase gene

    Energy Technology Data Exchange (ETDEWEB)

    Chen Libo, E-mail: libochen888@hotmail.com [Department of Nuclear Medicine, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Guo Guoying [Xinyuan Institute of Medicine and Biotechnology, School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Liu Tianjing; Guo Lihe [Division of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Zhu Ruisen [Department of Nuclear Medicine, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China)

    2011-07-15

    Herpes simplex virus thymidine kinase (HSV-TK) gene/ganciclovir (GCV) system has been widely used as a traditional gene therapy modality, and the sodium/iodide symporter gene (NIS) has been found to be a novel therapeutic gene. Since the therapeutic effects of radioiodine therapy or prodrug chemotherapy on cancers following NIS or HSV-TK gene transfer need to be enhanced, this study was designed to investigate the feasibility of radiochemotherapy for hepatocarcinoma via coexpression of NIS gene and HSV-TK gene. Methods: HepG2 cells were stably transfected with NIS, TK and GFP gene via recombinant lentiviral vector and named HepG2/NTG. Gene expression was examined by reverse transcriptase polymerase chain reaction, fluorescence imaging and iodide uptake. The therapeutic effects were assessed by MTT assay and clonogenic assay. Results: HepG2/NTG cells concentrated {sup 125}I{sup -} up to 76-fold higher than the wild-type cells within 20 min, and the efflux happened with a T{sub 1/2eff} of less than 10 min. The iodide uptake in HepG2/NTG cells was specifically inhibited by sodium perchlorate. Dose-dependent toxicity to HepG2/NTG cells by either GCV or {sup 131}I was revealed by clonogenic assay and MTT assay, respectively. The survival rate of HepG2/NTG cells decreased to 49.7%{+-}2.5%, 43.4%{+-}2.8% and 8.6%{+-}1.2% after exposure to {sup 131}I, GCV and combined therapy, respectively. Conclusion: We demonstrate that radiochemotherapy of hepatocarcinoma via lentiviral-mediated coexpression of NIS gene and HSV-TK gene leads to stronger killing effect than single treatment, and in vivo studies are needed to verify these findings.

  14. Sorption-reduction coupled gold recovery process boosted by Pycnoporus sanguineus biomass: Uptake pattern and performance enhancement via biomass surface modification.

    Science.gov (United States)

    Shi, Chaohong; Zhu, Nengwu; Kang, Naixin; Wu, Pingxiao; Zhang, Xiaoping; Zhang, Yanhong

    2017-09-01

    Biorecovery is emerging as a promising process to retrieve gold from secondary resources. The present study aimed to explore the uptake pattern of Pycnoporus sanguineus biomass for gold, identify the effective functional groups in gold recovery process, and thus further intensify the process via microbial surface modification. Results showed that P. sanguineus biomass could effectively recover gold with the formation of highly crystal AuNPs without any exogeneous electron donor. Under the conditions of various initial gold concentrations (1.0, 2.0, and 3.0 mM), biomass dosage of 2.0 g/L, solution pH value of 4.0, and incubation temperature of 30°C, the uptake equilibrium established after 4, 8, and 12 h, respectively. The uptake process could be well described by pseudo-second order kinetics model (R2  = 0.9988) and Langmuir isotherm model (R2  = 0.9958). The maximum uptake capacity of P. sanguineus reached as high as 358.69 mg/g. Further analysis indicated that amino, carboxyl and hydroxyl groups positively contributed to the uptake process. Among them, amino group significantly favored the uptake of gold during recovery process. When P. sanguineus biomass was modified by introduction of amino group, the gold uptake process was successfully intensified by shortening the uptake period and enhancing the uptake capacity. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1314-1322, 2017. © 2017 American Institute of Chemical Engineers.

  15. Enzymatically Modified Low-Density Lipoprotein Promotes Foam Cell Formation in Smooth Muscle Cells via Macropinocytosis and Enhances Receptor-Mediated Uptake of Oxidized Low-Density Lipoprotein.

    Science.gov (United States)

    Chellan, Bijoy; Reardon, Catherine A; Getz, Godfrey S; Hofmann Bowman, Marion A

    2016-06-01

    Enzyme-modified nonoxidized low-density lipoprotein (ELDL) is present in human atherosclerotic lesions. Our objective is to understand the mechanisms of ELDL uptake and its effects on vascular smooth muscle cells (SMC). Transformation of murine aortic SMCs into foam cells in response to ELDL was analyzed. ELDL, but not acetylated or oxidized LDL, was potent in inducing SMC foam cell formation. Inhibitors of macropinocytosis (LY294002, wortmannin, amiloride) attenuated ELDL uptake. In contrast, inhibitors of receptor-mediated endocytosis (dynasore, sucrose) and inhibitor of caveolae-/lipid raft-mediated endocytosis (filipin) had no effect on ELDL uptake in SMC, suggesting that macropinocytosis is the main mechanism of ELDL uptake by SMC. Receptor for advanced glycation end products (RAGE) is not obligatory for ELDL-induced SMC foam cell formation, but primes SMC for the uptake of oxidized LDL in a RAGE-dependent manner. ELDL increased intracellular reactive oxygen species, cytosolic calcium, and expression of lectin-like oxidized LDL receptor-1 in wild-type SMC but not in RAGE(-/-) SMC. The macropinocytotic uptake of ELDL is regulated predominantly by intracellular calcium because ELDL uptake was completely inhibited by pretreatment with the calcium channel inhibitor lacidipine in wild-type and RAGE(-/-) SMC. This is in contrast to pretreatment with PI3 kinase inhibitors which completely prevented ELDL uptake in RAGE(-/-) SMC, but only partially in wild-type SMC. ELDL is highly potent in inducing foam cells in murine SMC. ELDL endocytosis is mediated by calcium-dependent macropinocytosis. Priming SMC with ELDL enhances the uptake of oxidized LDL. © 2016 American Heart Association, Inc.

  16. Ciliary neurotrophic factor protects striatal neurons against excitotoxicity by enhancing glial glutamate uptake.

    Directory of Open Access Journals (Sweden)

    Corinne Beurrier

    Full Text Available Ciliary neurotrophic factor (CNTF is a potent neuroprotective cytokine in different animal models of glutamate-induced excitotoxicity, although its action mechanisms are still poorly characterized. We tested the hypothesis that an increased function of glial glutamate transporters (GTs could underlie CNTF-mediated neuroprotection. We show that neuronal loss induced by in vivo striatal injection of the excitotoxin quinolinic acid (QA was significantly reduced (by approximately 75% in CNTF-treated animals. In striatal slices, acute QA application dramatically inhibited corticostriatal field potentials (FPs, whose recovery was significantly higher in CNTF rats compared to controls (approximately 40% vs. approximately 7%, confirming an enhanced resistance to excitotoxicity. The GT inhibitor DL-threo-beta-benzyloxyaspartate greatly reduced FP recovery in CNTF rats, supporting the role of GT in CNTF-mediated neuroprotection. Whole-cell patch-clamp recordings from striatal medium spiny neurons showed no alteration of basic properties of striatal glutamatergic transmission in CNTF animals, but the increased effect of a low-affinity competitive glutamate receptor antagonist (gamma-D-glutamylglycine also suggested an enhanced GT function. These data strongly support our hypothesis that CNTF is neuroprotective via an increased function of glial GTs, and further confirms the therapeutic potential of CNTF for the clinical treatment of progressive neurodegenerative diseases involving glutamate overflow.

  17. Reducing plant uptake of PAHs by cationic surfactant-enhanced soil retention

    Energy Technology Data Exchange (ETDEWEB)

    Lu Li, E-mail: ll19840106@zju.edu.c [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong, E-mail: zlz@zju.edu.c [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, Zhejiang University, Hangzhou, Zhejiang 310029 (China)

    2009-06-15

    Reducing the transfer of contaminants from soils to plants is a promising approach to produce safe agricultural products grown on contaminated soils. In this study, 0-400 mg/kg cetyltrimethylammonium bromide (CTMAB) and dodecylpyridinium bromide (DDPB) were separately utilized to enhance the sorption of PAHs onto soils, thereby reducing the transfer of PAHs from soil to soil solution and subsequently to plants. Concentrations of phenanthrene and pyrene in vegetables grown in contaminated soils treated with the cationic surfactants were lower than those grown in the surfactant-free control. The maximum reductions of phenanthrene and pyrene were 66% and 51% for chrysanthemum (Chrysanthemum coronarium L.), 62% and 71% for cabbage (Brassica campestris L.), and 34% and 53% for lettuce (Lactuca sativa L.), respectively. Considering the impacts of cationic surfactants on plant growth and soil microbial activity, CTMAB was more appropriate to employ, and the most effective dose was 100-200 mg/kg. - Cationic surfactants could enhance the retention of PAHs in soil, and reduce PAH transfer to and accumulation in vegetables.

  18. Greenhouse evaluation of EDTA effectiveness at enhancing Cd, Cr, and Ni uptake in Helianthus annuus and Thlaspi caerulescens

    Energy Technology Data Exchange (ETDEWEB)

    Munn, J.; January, M.; Cutright, T.J. [Dept. Civil Engineering, The Univ. of Akron, OH (United States)

    2008-04-15

    Background, aims and scope. Phytoremediation is a promising means for the treatment of heavy metal contamination. Although several species have been identified as hyperaccumulators, most studies have been conducted with only one metal. Experiments were conducted to investigate the ability of Helianthus annuus and Thlaspi caerulescens to simultaneously uptake Cd, Cr and Ni. Materials and methods. The efficiency of plants grown in a sandy-loam soil was investigated. The ability of two EDTA concentrations (0.1 and 0.3 g kg{sup -1}) for enhancing the phytoremediation of Cd, Cr and Ni at two different metal concentrations (24.75 mg kg{sup -1} and 90 mg kg{sup -1}) was studied. Results. Thlaspi hyperaccumulated Ni with 0.1 g kg{sup -1} EDTA. When the EDTA dosage was increased to 0.3 g kg{sup -1}, Thlaspi was able to hyperaccumulate both Ni and Cr. Since Thlaspi is a low-biomass plant, it was considered insufficient for full-scale applications. Helianthus annuus hyperacummulated Cr (with 0.1 g kg{sup -1} EDTA) and Cd (0.3 g kg{sup -1} EDTA). Discussion. When the contamination was 8.25 mg kg{sup -1} per metal, the total metal uptake was 10-25% (1.35 to 2.12 mg) higher and had the same uptake selectivity (Cr>>Cd>Ni) for both EDTA levels. It was hypothesized that complexation with EDTA interfered with Ni translocation. For these experiments, the optimal results were obtained with the H. annuus-0.1 g kg{sup -1} EDTA combination. Conclusions. Although the use of EDTA did increase the amount of metal that could be extracted, care should be taken during in-situ field applications. Chelators can also increase the amount of metals that are leached past the root zone. Metal leaching and subsequent migration could lead to ground water contamination as well as lead to new soil contamination. Recommendations and perspectives. Additional research to identify the optimal EDTA dosage for field applications is warranted. This is necessary to ensure that the metals do not leach past the

  19. AMF Inoculation Enhances Growth and Improves the Nutrient Uptake Rates of Transplanted, Salt-Stressed Tomato Seedlings

    Directory of Open Access Journals (Sweden)

    Astrit Balliu

    2015-12-01

    Full Text Available The study aimed to investigate the effects of commercially available AMF inoculate (Glomus sp. mixture on the growth and the nutrient acquisition in tomato (Solanumlycopersicum L. plants directly after transplanting and under different levels of salinity. Inoculated (AMF+ and non-inoculated (AMF− tomato plants were subjected to three levels of NaCl salinity (0, 50, and 100 mM·NaCl. Seven days after transplanting, plants were analyzed for dry matter and RGR of whole plants and root systems. Leaf tissue was analyzed for mineral concentration before and after transplanting; leaf nutrient content and relative uptake rates (RUR were calculated. AMF inoculation did not affect plant dry matter or RGR under fresh water-irrigation. The growth rate of AMF−plants did significantly decline under both moderate (77% and severe (61% salt stress compared to the fresh water-irrigated controls, while the decline was much less (88% and 75%,respectivelyand statistically non-significant in salt-stressed AMF+ plants. Interestingly, root system dry matter of AMF+ plants (0.098 g plant–1 remained significantly greater under severe soil salinity compared to non-inoculated seedlings (0.082 g plant–1. The relative uptake rates of N, P, Mg, Ca, Mn, and Fe were enhanced in inoculated tomato seedlings and remained higher under (moderate salt stress compared to AMF− plants This study suggests that inoculation with commercial AMF during nursery establishment contributes to alleviation of salt stress by maintaining a favorable nutrient profile. Therefore, nursery inoculation seems to be a viable solution to attenuate the effects of increasing soil salinity levels, especially in greenhouses with low natural abundance of AMF spores.

  20. Background {sup 18}F-FDG uptake in positron emission mammography (PEM): Correlation with mammographic density and background parenchymal enhancement in breast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Hye Ryoung, E-mail: huilings@hanmail.net [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Moon, Woo Kyung, E-mail: moonwk@snu.ac.kr [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Chun, In Kook, E-mail: inkook.chun@gmail.com [Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Eo, Jae Seon, E-mail: jaeseon76@gmail.com [Department of Nuclear Medicine, Korea University Guro Hospital, 148 Gurodongro, Guro-gu, Seoul 152-703 (Korea, Republic of); Jeyanth, Joseph Xavier, E-mail: jeyanth7@snu.ac.kr [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Chang, Jung Min, E-mail: imchangjm@gmail.com [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Cho, Nariya, E-mail: river7774@gmail.com [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Kang, Keon Wook, E-mail: kangkw@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of)

    2013-10-01

    We aimed to determine whether background {sup 18}F-FDG uptake in positron emission mammography (PEM) was related to mammographic density or background parenchymal enhancement in breast MRI. Methods: We studied a total of 52 patients (mean age, 50.9 years, 26 premenopausal, 26 postmenopausal) with newly diagnosed breast cancer who underwent {sup 18}F-FDG PEM (positron emission mammography), conventional mammography and breast MRI. The background mean {sup 18}F-FDG uptake value on PEM was obtained by drawing a user-defined region of interest (ROI) in a normal area of the contralateral breast. We reviewed the mammography retrospectively for overall breast density of contralateral breast according to the four-point scale (grade 1–4) of the Breast Imaging Reporting and Data System (BI-RADS) classification. The background parenchymal enhancement of breast MRI was classified as minimal, mild, moderate, or marked. All imaging findings were interpreted by two readers in consensus without knowledge of image findings of other modalities. Results: Multiple linear regression analysis revealed a significant correlation between background {sup 18}F-FDG uptake on PEM and mammographic density after adjustment for age and menopausal status (P < 0.01), but not between background {sup 18}F-FDG uptake on PEM and background parenchymal enhancement on MRI. Conclusion: Background {sup 18}F-FDG uptake on PEM significantly increases as mammographic density increases. Background parenchymal enhancement in breast MRI was not an independent predictor of the background {sup 18}F-FDG uptake on PEM unlike mammographic density.

  1. Quantitative assessment of cellular uptake and cytosolic access of antibody in living cells by an enhanced split GFP complementation assay.

    Science.gov (United States)

    Kim, Ji-sun; Choi, Dong-Ki; Park, Seong-wook; Shin, Seung-Min; Bae, Jeomil; Kim, Dong-Myung; Yoo, Tae Hyeon; Kim, Yong-Sung

    2015-11-27

    Considering the number of cytosolic proteins associated with many diseases, development of cytosol-penetrating molecules from outside of living cells is highly in demand. To gain access to the cytosol after cellular uptake, cell-penetrating molecules should be released from intermediate endosomes prior to the lysosomal degradation. However, it is very challenging to distinguish the pool of cytosolic-released molecules from those trapped in the endocytic vesicles. Here we describe a method to directly demonstrate the cytosolic localization and quantification of cytosolic amount of a cytosol-penetrating IgG antibody, TMab4, based on enhanced split GFP complementation system. We generated TMab4 genetically fused with one GFP fragment and separately established HeLa cells expressing the other GFP fragment in the cytosol such that the complemented GFP fluorescence is observed only when extracellular-treated TMab4 reaches the cytosol after cellular internalization. The high affinity interactions between streptavidin-binding peptide 2 and streptavidin was employed as respective fusion partners of GFP fragments to enhance the sensitivity of GFP complementation. With this method, cytosolic concentration of TMab4 was estimated to be about 170 nM after extracellular treatment of HeLa cells with 1 μM TMab4 for 6 h. We also found that after cellular internalization into living cells, nearly 1.3-4.3% of the internalized TMab4 molecules escaped into the cytosol from the endocytic vesicles. Our enhanced split GFP complementation assay provides a useful tool to directly quantify cytosolic amount of cytosol-penetrating agents and allows cell-based high-throughput screening for cytosol-penetrating agents with increased endosomal-escaping activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Quantitative assessment of cellular uptake and cytosolic access of antibody in living cells by an enhanced split GFP complementation assay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-sun; Choi, Dong-Ki; Park, Seong-wook; Shin, Seung-Min; Bae, Jeomil [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Kim, Dong-Myung [Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Yoo, Tae Hyeon [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Kim, Yong-Sung, E-mail: kimys@ajou.ac.kr [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

    2015-11-27

    Considering the number of cytosolic proteins associated with many diseases, development of cytosol-penetrating molecules from outside of living cells is highly in demand. To gain access to the cytosol after cellular uptake, cell-penetrating molecules should be released from intermediate endosomes prior to the lysosomal degradation. However, it is very challenging to distinguish the pool of cytosolic-released molecules from those trapped in the endocytic vesicles. Here we describe a method to directly demonstrate the cytosolic localization and quantification of cytosolic amount of a cytosol-penetrating IgG antibody, TMab4, based on enhanced split GFP complementation system. We generated TMab4 genetically fused with one GFP fragment and separately established HeLa cells expressing the other GFP fragment in the cytosol such that the complemented GFP fluorescence is observed only when extracellular-treated TMab4 reaches the cytosol after cellular internalization. The high affinity interactions between streptavidin-binding peptide 2 and streptavidin was employed as respective fusion partners of GFP fragments to enhance the sensitivity of GFP complementation. With this method, cytosolic concentration of TMab4 was estimated to be about 170 nM after extracellular treatment of HeLa cells with 1 μM TMab4 for 6 h. We also found that after cellular internalization into living cells, nearly 1.3–4.3% of the internalized TMab4 molecules escaped into the cytosol from the endocytic vesicles. Our enhanced split GFP complementation assay provides a useful tool to directly quantify cytosolic amount of cytosol-penetrating agents and allows cell-based high-throughput screening for cytosol-penetrating agents with increased endosomal-escaping activity.

  3. Chelant-enhanced heavy metals uptake by Eucalyptus trees under controlled deficit irrigation

    Science.gov (United States)

    Fine, Pinchas; Rathod, Paresh; Beriozkin, Anna; Ein-Gal, Oz; Hass, Amir

    2014-05-01

    Enhancement of phytoremediation of heavy metal polluted soils employs organic ligands, aimed to solubilize, phytoextract and translocate metals into the canopy. The use of more persistent chelants (e.g. EDTA) is phasing out due to concerns over their role in the environment. We tested the hypothesis that controlled deficit irrigation (CDI) of the fast growing, salinity resistant Eucalyptus camaldulensis coupled with timely EDTA application enhances sediment phytoremediation while minimizing leaching of metal complexes below the root-zone. This was tested in 220-L lysimeters packed with sand mixed with metals polluted biosolids. One year old trees were brought under CDI with tap or RO water for two growing seasons. EDTA, EDDS and citric acid fertigation at 2 mM started in each May for 2.5-3.5 months, and prescribed soil leaching and sampling of tree leaves started thereafter. While all 3 chelants solubilized biosolids metal in batch extraction (EDDS often being the more efficient), EDTA was the only to increased metal concentrations both in the soil solution and in the Eucalyptus leaves. The average concentrations in the soil solution and in the leaves, in the EDTA vs. control (chelant-free) treatments, all respectively, were: Cd - 200 mg L-1 vs. 1.0, and 67 vs. 21 mg kg-1; Cu: 90 vs. 1.5 mg L-1, and 17 vs. 3.0 mg kg-1; Cr: 4.0 vs. 1.4 mg L-1, and 3.0 vs. 1.0 mg kg-1; Ni: 60 mg L-1 vs. 14, and 20 vs. 6.0 mg kg-1; Pb: >44 vs. 0.1 mg L-1, and 9.0 vs. 1.0 mg kg-1; and Zn: 650 vs. 4.0 mg L-1 and 200 vs. 70 mg kg-1. While EDDS was undetectable in all the leachates, EDTA concentrated to up to 100 mM. At 10 mM soil solution concentration, EDDS half-life in acclimated lysimeter media was 5-11 days and that of EDTA was ≥27-d. The study suggests that sustainable phytostabilization and phytoextraction of heavy metals are achievable under CDI with EDTA augmentation at low dose. This was yet futile with the biodegradable EDDS and citric acid. CDI with RO water further widened

  4. Enhanced terrestrial carbon uptake: global drivers and implications for the growth rate of atmospheric CO2.

    Science.gov (United States)

    Keenan, Trevor F.; Prentice, Colin; Canadell, Josep; Williams, Christopher; Han, Wang; Riley, William; Zhu, Qing; Koven, Charlie; Chambers, Jeff

    2017-04-01

    In this presentation we will focus on using decadal changes in the global carbon cycle to better understand how ecosystems respond to changes in CO2 concentration, temperature, and water and nutrient availability. Using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple process-based global vegetation models, we examine the causes and consequences of the long-term changes in the terrestrial carbon sink. We show that over the past century the sink has been greatly enhanced, largely due to the effect of elevated CO2 on photosynthesis dominating over warming induced increases in respiration. We also examine the relative roles of greening, water and nutrients, along with individual events such as El Nino. We show that a slowdown in the rate of warming over land since the start of the 21st century likely led to a large increase in the sink, and that this increase was sufficient to lead to a pause in the growth rate of atmospheric CO2. We also show that the recent El Nino resulted in the highest growth rate of atmospheric CO2 ever recorded. Our results provide evidence of the relative roles of CO2 fertilization and warming induced respiration in the global carbon cycle, along with an examination of the impact of climate extremes.

  5. Methanolic extract of Momordica cymbalaria enhances glucose uptake in L6 myotubes in vitro by up-regulating PPAR-γ and GLUT-4.

    Science.gov (United States)

    Kumar, Puttanarasaiah Mahesh; Venkataranganna, Marikunte V; Manjunath, Kirangadur; Viswanatha, Gollapalle L; Ashok, Godavarthi

    2014-12-01

    The present study was undertaken to evaluate the influence of the methanolic fruit extract of Momordica cymbalaria (MFMC) on PPARγ (Peroxisome Proliferator Activated Receptor gamma) and GLUT-4 (Glucose transporter-4) with respect to glucose transport. Various concentrations of MFMC ranging from 62.5 to 500 μg·mL(-1) were evaluated for glucose uptake activity in vitro using L6 myotubes, rosiglitazone was used as a reference standard. The MFMC showed significant and dose-dependent increase in glucose uptake at the tested concentrations, further, the glucose uptake activity of MFMC (500 μg·mL(-1)) was comparable with rosigilitazone. Furthermore, MFMC has shown up-regulation of GLUT-4 and PPARγ gene expressions in L6 myotubes. In addition, the MFMC when incubated along with cycloheximide (CHX), which is a protein synthesis inhibitor, has shown complete blockade of glucose uptake. This indicates that new protein synthesis is required for increased GLUT-4 translocation. In conclusion, these findings suggest that MFMC is enhancing the glucose uptake significantly and dose dependently through the enhanced expression of PPARγ and GLUT-4 in vitro. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  6. MR-guided focused ultrasound: enhancement of intratumoral uptake of [3H]-docetaxel in vivo

    Science.gov (United States)

    Chen, Lili; Mu, Zhaomei; Hachem, Paul; Ma, C.-M.; Wallentine, Annie; Pollack, Alan

    2010-12-01

    The purpose of this study is to quantify the enhancement of [3H]-docetaxel in implanted prostate tumors treated with MR-guided pulsed focused ultrasound (MRgFUS). Human prostate cancer, LNCaP cells in 25 µl, were implanted into the prostates of male nude mice. The tumor growth was directly monitored on MRI. When the tumor reached a designated size, MRgFUS treatment was performed using a focused ultrasound treatment system (InSightec ExAblate 2000) with a 1.5 T GE MR scanner. The tumor-bearing animals were randomly divided into three groups: group 1, MRgFUS treatment + [3H]-docetaxel; group 2, [3H]-docetaxel only and group 3, as a control. Animals in group 1 were treated with MRgFUS non-invasively. Immediately after the treatment, the animals received a single dose of tail vein injection of docetaxel at 15 mg kg-1 mixed with [3H]-docetaxel at 50 uCi kg-1 in a total volume of 150 µl. Animals in group 2 were treated the same as in group one, however without MRgFUS treatment. Animals in group 3 were treated as a control. Animals were sacrificed 30 min after i.v. injections regardless of whether or not they received focused ultrasound. Tumors were removed and processed. The radioactivity of [3H]-docetaxel in the tumor tissue was quantitatively measured by a liquid scintillation counter. Our study showed that all animals tolerated the MRgFUS treatment well. Our data showed increased 3H-docetaxel concentration in the tumor in the MRgFUS-treated group (1079 ± 132 cmp/75 mg) versus those without MRgFUS treatment (524 ± 201 cmp/75 mg) with P = 0.037.

  7. Chelant-enhanced heavy metal uptake by Eucalyptus trees under controlled deficit irrigation.

    Science.gov (United States)

    Fine, Pinchas; Paresh, Rathod; Beriozkin, Anna; Hass, Amir

    2014-09-15

    We tested the hypothesis that controlled deficit irrigation (CDI) of the fast growing, salinity resistant Eucalyptus camaldulensis tree with timely EDTA application can enhance sediment clean-up while minimizing leaching of metal complexes. 220-L lysimeters containing a sand-metal-polluted sludge mixture. Established saplings were irrigated with tap or desalinized (RO) water with/without 4-times daily addition of EDTA, EDDS and citric acid. In the 2nd season (2008/9) the chelates were added at 2 mM for ≈ 70 summer days. Diagnostic leaves and soil solution compositions were regularly monitored, the latter by applying prescribed leaching at an overall leaching percentage of ≈ 0.4%. While the three chelants solubilized sludge metals in batch extraction, EDDS often being the more efficient chelant, EDTA only was effective in the soil system. Leachate and leaves peak average concentrations in EDTA treatment vs. the control treatments were: Cd: 200 mg L(-1) vs. 1.0 and 67 vs. 21 mg kg(-1); Cu: 90 vs. 1.5 mg L(-1) and 17 vs. 3.0 mg kg(-1); Ni: 60 mg L(-1) vs. 14 and 20 vs. 6.0 mg kg(-1); Pb: >44 vs. 0.1 mg L(-1) and 9.0 vs. 1.0 mg kg(-1); and Zn: 650 vs. 4.0 mg L(-1) and 200 vs. 70 mg kg(-1), all respectively. Peak average leachate EDTA concentration was >60 mM, yet acclimating soil microflora gradually degraded most all the EDTA. In incubation study, EDDS and EDTA half-lives in acclimated lysimeter media were 5-11 days and ≥ 27 days, respectively. It suggests that sustainable phytoextraction of heavy metals is feasible under careful CDI with EDTA (yet not with biodegradable chelants) augmentation at low doses. Despite that the eucalypt was highly salinity (and EDTA) resistant, CDI using RO water further reduces soil solution salinity, thus increasing the usefulness of this remediation technique. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Enhancement of glucose uptake in skeletal muscle L6 cells and insulin secretion in pancreatic hamster-insulinoma-transfected cells by application of non-thermal plasma jet

    Science.gov (United States)

    Kumar, Naresh; Kaushik, Nagendra K.; Park, Gyungsoon; Choi, Eun H.; Uhm, Han S.

    2013-11-01

    Type-II diabetes Mellitus is characterized by defects in insulin action on peripheral tissues, such as skeletal muscle, adipose tissue, and liver and pancreatic beta cells. Since the skeletal muscle accounts for approximately 75% of insulin-stimulated glucose-uptake in our body, impaired insulin secretion from defected beta cell plays a major role in the afflicted glucose homoeostasis. It was shown that the intracellular reactive oxygen species and nitric oxide level was increased by non-thermal-plasma treatment in ambient air. These increased intracellular reactive species may enhance glucose uptake and insulin secretion through the activation of intracellular calcium (Ca+) and cAMP production.

  9. Evaluation of 5'-deoxy-5'-[F-18]fluorothymidine as a tracer of intracellular thymidine phosphorylase activity

    Energy Technology Data Exchange (ETDEWEB)

    Grierson, John R. [Department of Radiology, University of Washington, Seattle, WA 98195 (United States)]. E-mail: grierson@u.washington.edu; Brockenbrough, J. Scott [Department of Radiology, University of Washington, Seattle, WA 98195 (United States); Rasey, Janet S. [Department of Radiation Oncology, University of Washington, Seattle, WA 98195 (United States); Wiens, Linda W. [Department of Radiology, University of Washington, Seattle, WA 98195 (United States); Schwartz, Jeffery L. [Department of Radiation Oncology, University of Washington, Seattle, WA 98195 (United States); Jordan, Robert [Department of Radiation Oncology, University of Washington, Seattle, WA 98195 (United States); Vesselle, Hubert [Department of Radiology, University of Washington, Seattle, WA 98195 (United States)

    2007-07-15

    Two human cell lines (A549 and U937) with cytosolic thymidine phosphorylase (TP) activity were used to evaluate the potential of 5'-deoxy-5'-[F-18]fluorothymidine ([F-18]DFT) as a tracer of intracellular TP expression. Cellular metabolism of DFT led to the production of 5-[F-18]fluoro-2,5-dideoxy-D-ribose-1{alpha}-phosphate ([F-18]FddR-1P), in analogy to the metabolism of thymidine, which produces 2-deoxy-D-ribose-1{alpha}-phosphate (dR-1P). A549 cells showed the highest production rate of FddR-1P. After A549 cells were exposed to [F-18]DFT for 40 min, the relative intracellular concentration of [F-18]FddR-1P was more than sevenfold higher in cells than its precursor in the incubating medium. For the same amount of time, a twofold concentration was seen in U937 cells. However, uptake ratios did not rank with the corresponding TP activities found in cell extracts [TP activity ratio (U937:A549)=1.6] that were independently determined with a labeled thymidine/thymine cleavage assay. The discrepancy of TP activity ratios was traced to the instability of FddR-1P in cells. This was evident from the fact that cells accumulated radioactivity by producing FddR-1P, but activity also effluxed from cells over 1 h when the medium was subsequently made tracer free. The dominant labeled molecule released by cells was characterized as a neutral and lipophilic molecule, which was presumed to be a deoxynucleoside. Our results indicate that [F-18]DFT would not be effective for imaging TP expression because its initial metabolite undergoes further conversion to a diffusible secondary metabolite, allowing activity loss from cells.

  10. Addition of thymidine to culture media for accurate examination of thymidine-dependent small-colony variants of methicillin-resistant Staphylococcus aureus: a pilot study.

    Science.gov (United States)

    Horiuchi, Kazuki; Matsumoto, Takehisa; Ota, Yusuke; Kasuga, Eriko; Negishi, Tatsuya; Yaguchi, Tomomi; Sugano, Mitsutoshi; Honda, Takayuki

    2015-03-01

    Small-colony variants (SCVs) are slow-growing subpopulations of various auxotrophic bacterial strains. Thymidine-dependent SCVs (TD-SCVs) are unable to synthesize thymidine; hence, these variants fail to grow in a medium without thymidine. In this study, we used 10 TD-SCVs of Staphylococcus aureus, of which four strains possessed mecA. We compared the efficacy of a newly modified medium containing thymidine for the detection of TD-SCVs of methicillin-resistant S. aureus (MRSA) to the efficacy of routinely used laboratory media. We observed that none of the 10 TD-SCVs of S. aureus grew in Mueller-Hinton agar, and four TD-SCVs of MRSA failed to grow on all MRSA screening media, except for the ChromID™ MRSA medium. Laboratory tests conducted using medium with thymidine incorporated showed that thymidine did not affect the minimum inhibitory concentrations of oxacillin and cefoxitin for clinical isolates of S. aureus, and was able to detect MRSA, including TD-SCVs. These findings showed that thymidine-incorporated media are able to detect TD-SCVs of MRSA without altering the properties of other clinically isolated MRSA strains. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Fine Tuning of MOF-505 Analogues To Reduce Low-Pressure Methane Uptake and Enhance Methane Working Capacity.

    Science.gov (United States)

    Zhang, Mingxing; Zhou, Wei; Pham, Tony; Forrest, Katherine A; Liu, Wenlong; He, Yabing; Wu, Hui; Yildirim, Taner; Chen, Banglin; Space, Brian; Pan, Yi; Zaworotko, Michael J; Bai, Junfeng

    2017-09-11

    We present a crystal engineering strategy to fine tune the pore chemistry and CH4 -storage performance of a family of isomorphic MOFs based upon PCN-14. These MOFs exhibit similar pore size, pore surface, and surface area (around 3000 m(2)  g(-1) ) and were prepared with the goal to enhance CH4 working capacity. [Cu2 (L2)(H2 O)2 ]n (NJU-Bai 41: NJU-Bai for Nanjing University Bai's group), [Cu2 (L3)(H2 O)2 ]n (NJU-Bai 42), and [Cu2 (L4)(DMF)2 ]n (NJU-Bai 43) were prepared and we observed that the CH4 volumetric working capacity and volumetric uptake values are influenced by subtle changes in structure and chemistry. In particular, the CH4 working capacity of NJU-Bai 43 reaches 198 cm(3) (STP: 273.15 K, 1 atm) cm(-3) at 298 K and 65 bar, which is amongst the highest reported for MOFs under these conditions and is much higher than the corresponding value for PCN-14 (157 cm(3) (STP) cm(-3) ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils.

    Science.gov (United States)

    Li, Yinsheng; Tang, Hao; Hu, Yingxiu; Wang, Xiuhong; Ai, Xiaojie; Tang, Li; Matthew, Cory; Cavanagh, Jo; Qiu, Jiangping

    2016-05-05

    Individual and combined effects of enrofloxacin (EF) and cadmium (Cd) on the earthworm Eisenia fetida at environmentally relevant concentrations were investigated. EF is a veterinary antibiotic; Cd is an impurity in phosphatic fertiliser. For both, residues may accumulate in farm soils. In laboratory tests, over 98% of spiked EF was adsorbed by farm soils, with a half-life >8 weeks. However, earthworms absorbed less than 20% of spiked EF. Earthworms in soil with EF concentration 10 mg kg(-1) soil experienced transient oxidative stress and exhibited reduced burrowing activity and respiration after an 8-week exposure; EF at 0.1 and 1.0 mg kg(-1) soil did not elicit toxicity symptoms. When both were added, Cd did not affect EF uptake, but each increment of spiked EF increased Cd bioaccumulation and associated oxidative stress of earthworms, and also caused decreased burrow length and CO2 production. However, metallothionein induction was not affected. The enhanced toxicity of Cd to earthworms in the presence of EF at low environmental concentrations may have implications for the health and reproductive success of earthworm populations and highlights the importance of understanding effects of antibiotic contamination of farm soils, and of awareness of environmental effects from interaction between multiple contaminants. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Design of Thymidine Analogues Targeting Thymidilate Kinase of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Luc Calvin Owono Owono

    2013-01-01

    Full Text Available We design here new nanomolar antituberculotics, inhibitors of Mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt, by means of structure-based molecular design. 3D models of TMPKmt-inhibitor complexes have been prepared from the crystal structure of TMPKmt cocrystallized with the natural substrate deoxythymidine monophosphate (dTMP (1GSI for a training set of 15 thymidine analogues (TMDs with known activity to prepare a QSAR model of interaction establishing a correlation between the free energy of complexation and the biological activity. Subsequent validation of the predictability of the model has been performed with a 3D QSAR pharmacophore generation. The structural information derived from the model served to design new subnanomolar thymidine analogues. From molecular modeling investigations, the agreement between free energy of complexation (ΔΔGcom and Ki values explains 94% of the TMPKmt inhibition (pKi=-0.2924ΔΔGcom+3.234;R2=0.94 by variation of the computed ΔΔGcom and 92% for the pharmacophore (PH4 model (pKi=1.0206×pKipred-0.0832,  R2=0.92. The analysis of contributions from active site residues suggested substitution at the 5-position of pyrimidine ring and various groups at the 5′-position of the ribose. The best inhibitor reached a predicted Ki of 0.155 nM. The computational approach through the combined use of molecular modeling and PH4 pharmacophore is helpful in targeted drug design, providing valuable information for the synthesis and prediction of activity of novel antituberculotic agents.

  14. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yinsheng, E-mail: yinshengli@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China); Tang, Hao; Hu, Yingxiu; Wang, Xiuhong; Ai, Xiaojie; Tang, Li [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China); Matthew, Cory [Institute of Agriculture & Environment, Massey University, Private Bag 11-222, Palmerston North 4442 (New Zealand); Cavanagh, Jo [Landcare Research, PO Box 40, Lincoln 7640 (New Zealand); Qiu, Jiangping [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-05-05

    Highlights: • Enrofloxacin (EF) and cadmium (Cd) were independently adsorbed in soils. • EF accelerated and increased Cd bioaccumulation in earthworms. • At high concentration EF (10 mg kg{sup −1}) was toxic to earthworms. • EF enhanced Cd induced oxidative stress, and increased burrowing and respiration. • EF did not affect the Cd induced increase in metallothionein in earthworms. - Abstract: Individual and combined effects of enrofloxacin (EF) and cadmium (Cd) on the earthworm Eisenia fetida at environmentally relevant concentrations were investigated. EF is a veterinary antibiotic; Cd is an impurity in phosphatic fertiliser. For both, residues may accumulate in farm soils. In laboratory tests, over 98% of spiked EF was adsorbed by farm soils, with a half-life >8 weeks. However, earthworms absorbed less than 20% of spiked EF. Earthworms in soil with EF concentration 10 mg kg{sup −1} soil experienced transient oxidative stress and exhibited reduced burrowing activity and respiration after an 8-week exposure; EF at 0.1 and 1.0 mg kg{sup −1} soil did not elicit toxicity symptoms. When both were added, Cd did not affect EF uptake, but each increment of spiked EF increased Cd bioaccumulation and associated oxidative stress of earthworms, and also caused decreased burrow length and CO{sub 2} production. However, metallothionein induction was not affected. The enhanced toxicity of Cd to earthworms in the presence of EF at low environmental concentrations may have implications for the health and reproductive success of earthworm populations and highlights the importance of understanding effects of antibiotic contamination of farm soils, and of awareness of environmental effects from interaction between multiple contaminants.

  15. Edge effects resulting from forest fragmentation enhance carbon uptake and its vulnerability to climate change in temperate broadleaf forests

    Science.gov (United States)

    Reinmann, A.; Hutyra, L.

    2016-12-01

    Forest fragmentation resulting from land use and land cover change is a ubiquitous, ongoing global phenomenon with profound impacts on the growing conditions of the world's remaining forest. However, our understanding of forest carbon dynamics and their response to climate largely comes from unfragmented forest systems, which presents an important mismatch between the landscapes we study and those we aim to characterize. The temperate broadleaf forest makes a large contribution to the global terrestrial carbon sink, but is also the most heavily fragmented forest biome in the world. We use field measurements and geospatial analyses to characterize carbon dynamics in temperate broadleaf forest fragments. We show that forest growth and biomass increase by 89 ± 17% and 64 ± 12%, respectively, from the forest interior to edge. These ecosystem edge enhancements are not currently captured by models or approaches to quantifying regional C balance, but across southern New England, USA it increases carbon uptake and storage by 12.5 ± 2.9% and 9.6 ± 1.4%, respectively. However, we also find that forest growth near the edge declines three times faster than in the interior in response to heat stress during the growing season. Using climate projections, we show that future heat stress could reduce the forest edge growth enhancement by one-third by the end of the century. These findings contrast studies of edge effects in the world's other major forest biomes and indicate that the strength of the temperate broadleaf forest carbon sink and its capacity to mitigate anthropogenic carbon emissions may be stronger, but also more sensitive to climate change than previous estimates suggest.

  16. Role of Equilibrative Nucleobase Transporter 1/SLC43A3 as a Ganciclovir Transporter in the Induction of Cytotoxic Effect of Ganciclovir in a Suicide Gene Therapy with Herpes Simplex Virus Thymidine Kinase.

    Science.gov (United States)

    Furukawa, Junji; Inoue, Katsuhisa; Ohta, Kinya; Yasujima, Tomoya; Mimura, Yoshihisa; Yuasa, Hiroaki

    2017-01-01

    A suicide gene therapy using herpes simplex virus thymidine kinase (HSV-TK) with ganciclovir (GCV) has been under development as a tumor-targeted therapy; however, the mechanism of cellular GCV uptake, which is prerequisite in the therapy, has not been clarified. In an attempt to resolve this situation and gain information to optimize HSV-TK/GCV system for cancer therapy, we found that human equilibrative nucleobase transporter 1 (ENBT1) can transport GCV with a Michaelis constant of 2.75 mM in Madin-Darby canine kidney II (MDCKII) cells stably transfected with this transporter. In subsequent experiments using green fluorescent protein (GFP)-tagged ENBT1 (GFP-ENBT1) and HSV-TK, the uptake of GCV (30 μM), which was minimal in MDCKII cells and unchanged by their transfection with HSV-TK alone, was increased extensively by their transfection with GFP-ENBT1, together with HSV-TK. Accordingly, cytotoxicity, which was assessed by the WST-8 cell viability assay after the treatment of those cells with GCV (30 μM) for 72 hours, was induced in those transfected with GFP-ENBT1, together with HSV-TK but not in those transfected with HSV-TK alone. These results suggest that ENBT1 could facilitate GCV uptake and thereby enhance cytotoxicity in HSV-TK/GCV system. We also identified Helacyton gartleri (HeLa) and HepG2 as cancer cell lines that are rich with ENBT1 and A549, HCT-15 and MCF-7 as those poor with ENBT1. Accordingly, the HSV-TK/GCV system was effective in inducing cytotoxicity in the former but not in the latter. Thus, ENBT1 was found to be a GCV transporter that could enhance the performance of HSV-TK/GCV suicide gene therapy. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  17. Thymidine kinase 1 regulatory fine-tuning through tetramer formation

    DEFF Research Database (Denmark)

    Mutahir, Zeeshan; Clausen, Anders R.; Andersson, Karl-Magnus

    2013-01-01

    Abstract: Thymidine kinase 1 (TK1) provides a crucial precursor, deoxythymidine monophosphate, for nucleic acid synthesis, and the activity of TK1 increases by up to 200-fold during the S-phase of cell division in humans. An important part of the regulatory checkpoints is the ATP and enzyme...... in higher vertebrates and was especially pronounced in mammalian and bird TK1s. We suggest that the dimer form is the original form and that the tetramer originated in the animal lineage after the split of Dictyostelium and the lineages leading to invertebrates and vertebrates. The efficient switching...

  18. Reciprocal enhancement of uptake and toxicity of cadmium and calcium in rainbow trout (Oncorhynchus mykiss) liver mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Adiele, Reginald C.; Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3 (Canada)

    2010-03-01

    The interactive effects of cadmium (Cd) and calcium (Ca) on energy metabolism in rainbow trout liver mitochondria were studied to test the prediction that Ca would protect against Cd-induced mitochondrial liability. Isolated rainbow trout liver mitochondria were energized with malate and glutamate and exposed to increasing concentrations (5-100 {mu}M) of Cd and Ca singly and in combination at 15 {sup o}C. Accumulation of Cd and Ca in the mitochondria and mitochondrial respiration (oxygen consumption) rates were measured. Additionally, un-energized mitochondria were incubated with low doses (1 {mu}M) of Cd and Ca singly and in combination, with time-course measurements of cation accumulation/binding and oxygen consumption rates. In energized actively phosphorylating mitochondria, the uptake rates of both Cd and Ca were dose-dependent and enhanced when administered concurrently. Upon low-dose incubation, Cd accumulation was rapid and peaked in 5 min, while no appreciable uptake of Ca occurred. Functionally, the resting (state 4, ADP-limited) respiration rate was not affected in the dose-response exposure, but it decreased remarkably on low-dose incubation. Adenosine diphosphate (ADP)-stimulated respiration (state 3) rate was impaired dose-dependently with maximal inhibitions (at the highest dose, 100 {mu}M) of 32, 64 and 73% for Ca, Cd, and combined exposures, respectively. The combined effects of Ca and Cd suggested synergistic (more than additive) action and partial additivity of effects at low and higher doses of the two cations, respectively. Moreover, on a molar basis, Cd was twice as toxic as Ca to rainbow trout liver mitochondria and when combined, approximately 90% of the effects were attributable to Cd. The coupling efficiency, as measured by respiratory control ratio (RCR) and phosphorylation efficiency, measured as ADP/O ratio, both decreased as the exposure dosage and duration increased. In addition, Cd and Ca exposure decreased mitochondrial proton leak

  19. Some hints concerning phosphorus release and phosphorus uptake properties in enhanced biological phophorus removal; Empfehlungen zur Durchfuehrung und Auswertung von Phosphatrueckloese- und -aufnahmeversuchen

    Energy Technology Data Exchange (ETDEWEB)

    Scheer, H. [Hannover Univ. (Germany). Inst. fuer Siedlungswasserwirtschaft und Abfalltechnik

    1996-01-01

    Reproducible methods of analysis are necessary for the estimation of phosphorus release and phosphorus uptake properties of activated sludges in wastewater treatment plants using enhanced biological phosphorus removal (EBPR). These methods have to allow for comparisons and evaluations of different activated sludges impressed by EBPR. A phosphorus release and phosphorus uptake attempt modified for different operation facilities and conditions in wastewater treatment plants was developed. Using these methods phosphorus release and phosphorus uptake properties of activated sludges can be described qualitativley and quantitatively. (orig.) [Deutsch] Zur Abschaetzung der Phosphatrueckloese- und -aufnahmeeigenschaften eines belebten Schlammes bei Klaeranlagen mit vermehrter biologischer Phosphorelimination (BIO-P) bedarf es reproduzierbarer Untersuchungsmethoden, die einen Vergleich und eine Beurteilung hierzu durchgefuehrter Untersuchungen ermoeglichen. Hierzu wurde ein fuer klaeranlagenspezifische Betriebsbedingungen modifizierter Phosphatrueckloese- und -aufnahmeversuche entwickelt, mit dem die Phosphatrueckloese- und -aufnahmeeigenschaften eines belebten Schlammes qualitativ und quantitativ beschrieben werden koennen. (orig.)

  20. Effects of low-energy electrons on DNA constituents: effective cross sections for condensed thymidine

    Science.gov (United States)

    Panajotovic, Radmila

    2009-05-01

    Since the first experiments of low-energy electron scattering from condensed DNA [1] have been performed, the interest in studying low-energy electron-biomolecule interactions has been increasing. Knowledge of effective cross sections for single- and double-strand breaks of DNA and for vibrational and electronic excitation of nucleic bases and nucleosides are opening the door to better understanding of effects of radiation on live tissue and possibly indicating interaction pathways leading to gene mutations and cancer. The strong variation of effective cross sections for DNA single-strand breaks with incident electron energy and the resonant enhancement at 1 eV suggested that considerable damage is inflicted by very low-energy electrons to DNA, and indicates the important role of π* shape resonances in the bond-breaking process. However, the complexity of DNA, even if studied as a short single-strand chain, imposes a need to perform measurements on its isolated constituents, such as nucleic bases and nucleosides. Thymidine is one of the most important nucleosides of DNA and an important component of antiviral compounds. In the condensed phase, thymidine's 2'-deoxyribose ring is in the pentose sugar ring form, which is a true conformation of this nucleoside in DNA. Results from High-Resolution Electron Energy Loss [2] study of monomolecular films of thymidine will be discussed and the presence of resonances in the effective cross sections at incident energy below 5 eV will be commented as a possible indication of the dissociative electron attachment. In addition, results on the resonance structures in the effective cross sections for electronic excitations for the incident electron energy from 1.5 to 12 eV will be discussed as a possible pathway for strand brakes in DNA. [4pt] [1] Boudaiffa B, Cloutier P, Hunting D, Huels M A and Sanche L 2002 Rad. Res. 157 227-234[0pt] [2] Panajotovic R, Martin F, Cloutier P, Hunting, D, and Sanche L, 2006 Rad.Res. 165 452

  1. Enhanced cellular uptake of albumin-based lyophilisomes when functionalized with cell-penetrating peptide TAT in HeLa cells.

    Directory of Open Access Journals (Sweden)

    Etienne van Bracht

    Full Text Available Lyophilisomes are a novel class of biodegradable proteinaceous nano/micrometer capsules with potential use as drug delivery carrier. Cell-penetrating peptides (CPPs including the TAT peptide have been successfully implemented for intracellular delivery of a broad variety of cargos including various nanoparticulate pharmaceutical carriers. In the present study, lyophilisomes were modified using CPPs in order to achieve enhanced cellular uptake. Lyophilisomes were prepared by a freezing, annealing, and lyophilization method and a cystein-elongated TAT peptide was conjugated to the lyophilisomes using a heterobifunctional linker. Fluorescent-activated cell sorting (FACS was utilized to acquire a lyophilisome population with a particle diameter smaller than 1000 nm. Cultured HeLa, OVCAR-3, Caco-2 and SKOV-3 cells were exposed to unmodified lyophilisomes and TAT-conjugated lyophilisomes and examined with FACS. HeLa cells were investigated in more detail using a trypan blue quenching assay, confocal microscopy, and transmission electron microscopy. TAT-conjugation strongly increased binding and cellular uptake of lyophilisomes in a time-dependent manner in vitro, as assessed by FACS. These results were confirmed by confocal microscopy. Transmission electron microscopy indicated rapid cellular uptake of TAT-conjugated lyophilisomes via phagocytosis and/or macropinocytosis. In conclusion, TAT-peptides conjugated to albumin-based lyophilisomes are able to enhance cellular uptake of lyophilisomes in HeLa cells.

  2. Comparison of linear and nonlinear implementation of the compartmental tissue uptake model for dynamic contrast‐enhanced MRI

    Science.gov (United States)

    Sourbron, Steven; Irving, Benjamin; Tanderup, Kari; Schnabel, Julia A.; Chappell, Michael A.

    2016-01-01

    Purpose Fitting tracer kinetic models using linear methods is much faster than using their nonlinear counterparts, although this comes often at the expense of reduced accuracy and precision. The aim of this study was to derive and compare the performance of the linear compartmental tissue uptake (CTU) model with its nonlinear version with respect to their percentage error and precision. Theory and Methods The linear and nonlinear CTU models were initially compared using simulations with varying noise and temporal sampling. Subsequently, the clinical applicability of the linear model was demonstrated on 14 patients with locally advanced cervical cancer examined with dynamic contrast‐enhanced magnetic resonance imaging. Results Simulations revealed equal percentage error and precision when noise was within clinical achievable ranges (contrast‐to‐noise ratio >10). The linear method was significantly faster than the nonlinear method, with a minimum speedup of around 230 across all tested sampling rates. Clinical analysis revealed that parameters estimated using the linear and nonlinear CTU model were highly correlated (ρ ≥ 0.95). Conclusion The linear CTU model is computationally more efficient and more stable against temporal downsampling, whereas the nonlinear method is more robust to variations in noise. The two methods may be used interchangeably within clinical achievable ranges of temporal sampling and noise. Magn Reson Med 77:2414–2423, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:27605429

  3. Comparison of linear and nonlinear implementation of the compartmental tissue uptake model for dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Kallehauge, Jesper F; Sourbron, Steven; Irving, Benjamin; Tanderup, Kari; Schnabel, Julia A; Chappell, Michael A

    2017-06-01

    Fitting tracer kinetic models using linear methods is much faster than using their nonlinear counterparts, although this comes often at the expense of reduced accuracy and precision. The aim of this study was to derive and compare the performance of the linear compartmental tissue uptake (CTU) model with its nonlinear version with respect to their percentage error and precision. The linear and nonlinear CTU models were initially compared using simulations with varying noise and temporal sampling. Subsequently, the clinical applicability of the linear model was demonstrated on 14 patients with locally advanced cervical cancer examined with dynamic contrast-enhanced magnetic resonance imaging. Simulations revealed equal percentage error and precision when noise was within clinical achievable ranges (contrast-to-noise ratio >10). The linear method was significantly faster than the nonlinear method, with a minimum speedup of around 230 across all tested sampling rates. Clinical analysis revealed that parameters estimated using the linear and nonlinear CTU model were highly correlated (ρ ≥ 0.95). The linear CTU model is computationally more efficient and more stable against temporal downsampling, whereas the nonlinear method is more robust to variations in noise. The two methods may be used interchangeably within clinical achievable ranges of temporal sampling and noise. Magn Reson Med 77:2414-2423, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  4. Catabolism of exogenously supplied thymidine to thymine and dihydrothymine by platelets in human peripheral blood

    Energy Technology Data Exchange (ETDEWEB)

    Pero, R.W.; Johnson, D.; Olsson, A.

    1984-11-01

    The interference of platelets with the estimation of unscheduled DNA synthesis in human peripheral mononuclear leukocytes following genotoxic exposure was studied. A 96% reduction in the unscheduled DNA synthesis value was achieved by incubating (/sup 3/H)thymidine with platelet-rich plasma for 5 hr at 37 degrees. Using radioactive thymine-containing compounds, together with quantitative analyses based on thin-layer and ion-exchange chromatographies, we have shown that thymidine was converted to thymine which, in turn, was converted to dihydrothymine in platelet-rich plasma. The enzymes responsible were separated from platelet lysates by gel filtration and were identified as thymidine phosphorylase and dihydrothymine dehydrogenase. The phosphorylase reversibly catalyzed the formation of thymine from thymidine and converted bromodeoxyuridine to bromouracil. The dehydrogenase reversibly catalyzed the interconversion of thymine and dihydrothymine in a reaction dependent on NADP(H), and it was inhibited by diazouracil and by thymine. Nearly all the thymidine-catabolizing activity found in whole blood samples supplied exogenously with thymidine was accounted for by the platelets. Since most genetic toxicological tests that use blood samples do not involve removing platelets from the blood cell cultures, then it is concluded that precautions should be taken in the future to determine the influence of platelets on these test systems. This is particularly true for methods dependent on thymidine pulses such as unscheduled DNA synthesis, or those dependent on bromodeoxyuridine, such as sister chromatid exchanges, since this nucleoside is also a substrate for thymidine phosphorylase.

  5. Quantitative evaluation of contrast agent uptake in standard fat-suppressed dynamic contrast-enhanced MRI examinations of the breast.

    Science.gov (United States)

    Kousi, Evanthia; Smith, Joely; Ledger, Araminta E; Scurr, Erica; Allen, Steven; Wilson, Robin M; O'Flynn, Elizabeth; Pope, Romney J E; Leach, Martin O; Schmidt, Maria A

    2018-01-01

    To propose a method to quantify T 1 and contrast agent uptake in breast dynamic contrast-enhanced (DCE) examinations undertaken with standard clinical fat-suppressed MRI sequences and to demonstrate the proposed approach by comparing the enhancement characteristics of lobular and ductal carcinomas. A standard fat-suppressed DCE of the breast was performed at 1.5 T (Siemens Aera), followed by the acquisition of a proton density (PD)-weighted sequence, also fat suppressed. Both sequences were characterized with test objects (T 1 ranging from 30 ms to 2,400 ms) and calibration curves were obtained to enable T 1 calculation. The reproducibility and accuracy of the calibration curves were also investigated. Healthy volunteers and patients were scanned with Ethics Committee approval. The effect of B 0 field inhomogeneity was assessed in test objects and healthy volunteers. The T 1 of breast tumors was calculated at different time points (pre-, peak-, and post-contrast agent administration) for 20 patients, pre-treatment (10 lobular and 10 ductal carcinomas) and the two cancer types were compared (Wilcoxon rank-sum test). The calibration curves proved to be highly reproducible (coefficient of variation under 10%). T 1 measurements were affected by B 0 field inhomogeneity, but frequency shifts below 50 Hz introduced only 3% change to fat-suppressed T 1 measurements of breast parenchyma in volunteers. The values of T 1 measured pre-, peak-, and post-contrast agent administration demonstrated that the dynamic range of the DCE sequence was correct, that is, image intensity is approximately directly proportional to 1/T 1 for that range. Significant differences were identified in the width of the distributions of the post-contrast T 1 values between lobular and ductal carcinomas (P work has demonstrated the feasibility of fat-suppressed T 1 measurements as a tool for clinical studies. The proposed quantitative approach is practical, enabled the detection of differences between

  6. Thymidine kinase enzyme selective imaging radiopharmaceutical. {sup 99m}Tc(CO){sub 3}-Ganciclovir

    Energy Technology Data Exchange (ETDEWEB)

    Gedik, B.; Teksoez, S.; Ichedef, C.; Kilcar, A.Y.; Medine, E.I.; Ucar, E. [Ege Univ., Bornova, Izmir (Turkey). Dept. of Nuclear Applications

    2013-03-01

    The aim of this study is to radiolabel Ganciclovir, known as having selective antiviral properties against thymidine kinase, with technetium tricarbonylcore ({sup 99m}Tc(CO){sub 3}{sup +}) and to investigate the biological behavior of this complex in vitro and in vivo. Commercially provided Ganciclovir (GCV) was radiolabeled with {sup 99m}Tc(CO){sub 3}{sup +}. Initially, optimum radiolabeling conditions were determined by analyzing factors such as temperature, pH and time. Quality control of the radiolabeled compound was performed. The radiolabeling yield was found to be 97%. The {sup 99m}Tc(CO){sub 3}-GCV complex also displayed good in vitro stability during the 24 h period. In vitro cell uptake studies showed that the {sup 99m}Tc(CO){sub 3}-GCV complex is highly uptaken in A-549, PC-3, HeLa cell lines according to the control group {sup 99m}Tc(I)-tricarbonyl core. The knowledge gained from in vivo and in vitro studies of {sup 99m}Tc(CO){sub 3}-GCV could contribute to the development of a new HSV1-tk gene imaging agent. (orig.)

  7. [H-3]thymidine incorporation into whole liver as an alternative to [H-3]thymidine incorporation into DNA as a parameter of cell proliferation in regenerating liver tissue in rats

    NARCIS (Netherlands)

    de Jong, KP; Brinker, M; van Veen, M; Daemen, T; Scherphof, GL; Slooff, MJH

    1999-01-01

    OBJECTIVE: To monitor liver regeneration following partial hepatectomy, liver cell proliferation can be measured by assaying in vivo [H-3]thymidine incorporation into liver cell DNA. We hypothesized that [H-3]thymidine incorporation into whole liver tissue parallels [H-3]thymidine incorporation into

  8. Nuclear factor E2-related factor 2 knockdown enhances glucose uptake and alters glucose metabolism in AML12 hepatocytes.

    Science.gov (United States)

    Yuan, Xiaoyang; Huang, Huijing; Huang, Yi; Wang, Jinli; Yan, Jinhua; Ding, Ling; Zhang, Cuntai; Zhang, Le

    2017-05-01

    Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor known to induce the expression of a variety of antioxidant and detoxification genes. Recently, increasing evidence has revealed roles for Nrf2 in glucose, lipid, and energy metabolism; however, the exact functions of Nrf2 in hepatocyte biology are largely unclear. In the current study, the transient knockdown of Nrf2 via siRNA transfection enhanced the glucose uptake of fasting AML12 hepatocytes to 325.3 ± 11.1% ( P glucose metabolism were then examined in AML12 cells under both high-glucose (33 mmol/L) and low-glucose (4.5 mmol/L) conditions. NK lowered the gene and protein expression of the anti-oxidases heme oxygenase-1 and NAD(P)H: quinone oxidoreductase 1 and increased p-eukaryotic initiation factor-2α S51 , p-nuclear factor-κB p65 S276 , and its downstream proinflammatory factors, including interleukin-1 beta, tumor necrosis factor-α, matrix metalloproteinase 2, and matrix metalloproteinase 9, at the protein level. NK also altered the protein expression of fibroblast growth factor 21, glucose transporter type 4, insulin-like growth factor 1, forkhead box protein O1, p-AKT S473 , and p-GSK3α/β Y279/Y216 , which are involved in glucose uptake, glycogenesis, and gluconeogenesis in AML12 cells. Our results provide a comprehensive understanding of the central role of Nrf2 in the regulation of glucose metabolism in AML12 hepatocytes, in addition to its classical roles in the regulation of redox signaling, endoplasmic reticulum stress and proinflammatory responses, and support the potential of Nrf2 as a therapeutic target for the prevention and treatment of obesity and other associated metabolic syndromes. Impact statement Increasing evidence supports the complexity of Nrf2 functions beyond the antioxidant and detoxification response. Previous in vivo studies employing either Nrf2-knockout or Nrf2-activated mice have achieved a similar endpoint: protection against an obese and

  9. Nitrogen release, tree uptake, and ecosystem retention in a mid-rotation loblolly pine plantation following fertilization with 15N-enriched enhanced efficiency fertilizers.

    OpenAIRE

    Werner, Amy

    2013-01-01

    Nitrogen is the most frequently limiting nutrient in southern pine plantations.  Previous studies found that only 10 to 25% of applied urea fertilizer N is taken up by trees.  Enhanced efficiency fertilizers could increase tree uptake efficiency by controlling the release of N and/or stabilize N.  Three enhanced efficiency fertilizers were selected as a representation of fertilizers that could be used in forestry: 1) NBPT treated urea (NBPT urea), 2) polymer coated urea (PC urea), and 3) mono...

  10. Structural and Kinetic Characterization of Thymidine Kinase from Leishmania major.

    Directory of Open Access Journals (Sweden)

    Jennifer Timm

    2015-05-01

    Full Text Available Leishmania spp. is a protozoan parasite and the causative agent of leishmaniasis. Thymidine kinase (TK catalyses the transfer of the γ-phosphate of ATP to 2'-deoxythymidine (dThd forming thymidine monophosphate (dTMP. L. major Type II TK (LmTK has been previously shown to be important for infectivity of the parasite and therefore has potential as a drug target for anti-leishmanial therapy. In this study, we determined the enzymatic properties and the 3D structures of holo forms of the enzyme. LmTK efficiently phosphorylates dThd and dUrd and has high structural homology to TKs from other species. However, it significantly differs in its kinetic properties from Trypanosoma brucei TK since purines are not substrates of the enzyme and dNTPs such as dUTP inhibit LmTK. The enzyme had Km and kcat values for dThd of 1.1 μM and 2.62 s(-1 and exhibits cooperative binding for ATP. Additionally, we show that the anti-retroviral prodrug zidovudine (3-azido-3-deoxythymidine, AZT and 5'-modified dUrd can be readily phosphorylated by LmTK. The production of recombinant enzyme at a level suitable for structural studies was achieved by the construction of C-terminal truncated versions of the enzyme and the use of a baculoviral expression system. The structures of the catalytic core of LmTK in complex with dThd, the negative feedback regulator dTTP and the bi-substrate analogue AP5dT, were determined to 2.74, 3.00 and 2.40 Å, respectively, and provide the structural basis for exclusion of purines and dNTP inhibition. The results will aid the process of rational drug design with LmTK as a potential target for anti-leishmanial drugs.

  11. Enhanced washout of {sup 99m}Tc-tetrofosmin in hypertrophic cardiomyopathy: quantitative comparisons with regional {sup 123}I-BMIPP uptake and wall thickness determined by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Thet-Thet-Lwin, Tohoru; Takeda, Jin; Wu, Yuko; Fumikura, Keiji; Iida, Satoru; Kawano, Iwao; Yamaguchi, Yuji; Itai [Institute of Clinical Medicine, University of Tsukuba, Tennodai 1-1-1, 305-8575, Tsukuba-shi, Ibaraki-ken (Japan)

    2003-07-01

    The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 {beta}-methyl-p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment. Mean TF washout in the patients with HCM was significantly faster than that in normal control subjects (23.7{+-}5.7 vs 13.4{+-}4.1, P<0.0001). In the patients with HCM, TF washout showed an excellent correlation with MRI wall thickness (r=0.82, P<0.0001) and a good inverse correlation with regional BMIPP uptake (r=-0.72, P<0.0001). In addition, a good linear correlation was observed between TF uptake and MRI wall thickness in the 19 regional segments. In conclusion, the degree of TF washout corresponds well with the severity of myocardial wall thickness and the degree of metabolic abnormality in patients with HCM. These results suggest that enhanced TF washout might provide additional clinical information regarding metabolic alterations in HCM. (orig.)

  12. Canopy-level stomatal narrowing in adult Fagus sylvatica under O3 stress - means of preventing enhanced O3 uptake under high O3 exposure?

    Science.gov (United States)

    Matyssek, R; Baumgarten, M; Hummel, U; Häberle, K-H; Kitao, M; Wieser, G

    2015-01-01

    Spatio-temporally consistent O(3) doses are demonstrated in adult Fagus sylvatica from the Kranzberg Forest free-air fumigation experiment, covering cross-canopy and whole-seasonal scopes through sap flow measurement. Given O(3)-driven closure of stomata, we hypothesized enhanced whole-tree level O(3) influx to be prevented under enhanced O(3) exposure. Although foliage transpiration rate was lowered under twice-ambient O(3) around noon by 30% along with canopy conductance, the hypothesis was falsified, as O(3) influx was raised by 25%. Nevertheless, the twice-ambient/ambient ratio of O(3) uptake was smaller by about 20% than that of O(3) exposure, suggesting stomatal limitation of uptake. The O(3) response was traceable from leaves across branches to the canopy, where peak transpiration rates resembled those of shade rather than sun branches. Rainy/overcast-day and nightly O(3) uptake is quantified and discussed. Whole-seasonal canopy-level validation of modelled with sap flow-derived O(3) flux becomes available in assessing O(3) risk for forest trees. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Characterization of adducts formed in reactions of acrolein with thymidine and calf thymus DNA.

    Science.gov (United States)

    Pawłowicz, Agnieszka J; Kronberg, Leif

    2008-01-01

    Acrolein, an important industrial chemical and environmental contaminant, has been shown to interact with nucleic acids in vitro and in vivo. In this study, we examined the reactivity of acrolein towards thymidine and calf-thymus double- and single-stranded DNA in aqueous buffered solutions. LC-MS Analyses of the reaction mixture of acrolein with thymidine showed the formation of five structurally different adducts. The structures of the products were determined on the basis of mass spectrometry, UV absorbance, and (1)H- and (13)C-NMR spectroscopy. The adducts were identified as 3-(3-oxopropyl)thymidine (dT1), 3-[(tetrahydro-2,4-dihydroxypyran-3-yl)methyl]thymidine (dT2), 2-(hydroxymethyl)-5-(thymidin-3-yl)pent-2-enal (dT3), 3-hydroxy-2-methylidene-5-(thymidin-3-yl)pentanal (dT4), and 2-[(thymidin-3-yl)methyl]penta-2,4-dienal (dT5). The adducts dT2-dT5 were formed in reaction of dT1 with acrolein. In the reaction of acrolein with calf-thymus DNA, dT1 was the only adduct detected in the DNA hydrolysate.

  14. Dammarane-type triterpene extracts of Panax notoginseng root ameliorates hyperglycemia and insulin sensitivity by enhancing glucose uptake in skeletal muscle.

    Science.gov (United States)

    Kitamura, Kumiko; Takamura, Yusuke; Iwamoto, Taku; Nomura, Mitsuru; Iwasaki, Hideaki; Ohdera, Motoyasu; Murakoshi, Michiaki; Sugiyama, Keikichi; Matsuyama, Kazuki; Manabe, Yasuko; Fujii, Nobuharu L; Fushiki, Tohru

    2017-02-01

    Skeletal muscle is an important organ for controlling the development of type 2 diabetes. We discovered Panax notoginseng roots as a candidate to improve hyperglycemia through in vitro muscle cells screening test. Saponins are considered as the active ingredients of ginseng. However, in the body, saponins are converted to dammarane-type triterpenes, which may account for the anti-hyperglycemic activity. We developed a method for producing a dammarane-type triterpene extract (DTE) from Panax notoginseng roots and investigated the extract's potential anti-hyperglycemic activity. We found that DTE had stronger suppressive activity on blood glucose levels than the saponin extract (SE) did in KK-Ay mice. Additionally, DTE improved oral glucose tolerance, insulin sensitivity, glucose uptake, and Akt phosphorylation in skeletal muscle. These results suggest that DTE is a promising agent for controlling hyperglycemia by enhancing glucose uptake in skeletal muscle.

  15. Increased expression of six ZIP family genes by zinc (Zn) deficiency is associated with enhanced uptake and root-to-shoot translocation of Zn in barley (Hordeum vulgare).

    Science.gov (United States)

    Tiong, Jingwen; McDonald, Glenn; Genc, Yusuf; Shirley, Neil; Langridge, Peter; Huang, Chun Y

    2015-09-01

    Low zinc (Zn) in soils reduces yield and grain Zn content. Regulation of ZRT/IRT-like protein (ZIP) family genes is a major mechanism in plant adaptation to low and fluctuating Zn in soil. Although several Zn deficiency-inducible ZIP genes are identified in cereals, there has been no systematic study on the association of Zn deficiency-induced uptake and root-to-shoot translocation with expression of ZIP family genes. We measured Zn deficiency-induced uptake and root-to-shoot translocation of Zn in barley (Hordeum vulgare) plants by resupplying 0.5 μM Zn, and quantified the transcripts of thirteen HvZIP genes. Subcellular localization and tissue-specific expression were also determined for Zn deficiency-inducible HvZIP genes. Zn deficiency enhanced the capacity of uptake and root-to-shoot translocation of Zn, and sustained the enhanced capacity for 6 d after Zn resupply. Six HvZIP genes were highly induced in roots of Zn-deficient plants, and their proteins were localized in the plasma membrane. Tissue-specific expression in roots supports their roles in uptake and root-to-shoot translocation of Zn under low Zn conditions. Our results provide a comprehensive view on the physiological roles of ZIP genes in plant adaptation to low and fluctuating Zn in soil, and pave the way for development of new strategies to improve Zn-deficiency tolerance and biofortification in cereals. © 2015 Australian Centre for Plant Functional Genomics New Phytologist © 2015 New Phytologist Trust.

  16. Comparative active‐site mutation study of human and Caenorhabditis elegans thymidine kinase 1

    National Research Council Canada - National Science Library

    Skovgaard, Tine; Uhlin, Ulla; Munch‐Petersen, Birgitte

    2012-01-01

    The first step for the intracellular retention of several anticancer or antiviral nucleoside analogues is the addition of a phosphate group catalysed by a deoxyribonucleoside kinase such as thymidine kinase 1 (TK1...

  17. AMPK-dependent degradation of TXNIP upon energy stress leads to enhanced glucose uptake via GLUT1

    Science.gov (United States)

    Wu, Ning; Zheng, Bin; Shaywitz, Adam; Dagon, Yossi; Tower, Christine; Bellinger, Gary; Shen, Che-Hung; Wen, Jennifer; Asara, John; McGraw, Timothy E.; Kahn, Barbara B.; Cantley, Lewis C.

    2013-01-01

    Summary TXNIP is an α-arrestin family protein that is induced in response to glucose elevation. It has been shown to provide a negative feedback loop to regulate glucose uptake into cells, though the biochemical mechanism of action has been obscure. Here, we report that TXNIP suppresses glucose uptake directly by binding to the glucose transporter, Glut1, inducing Glut1 internalization through clathrin coated pits, as well as indirectly by reducing the level of Glut1 mRNA. In addition, we show that energy stress results in phosphorylation of TXNIP by AMP-dependent protein kinase (AMPK), leading to its rapid degradation. This suppression of TXNIP results in an acute increase in Glut1 function and an increase in Glut1 mRNA (hence total protein levels) for long-term adaptation. The glucose influx through GLUT1 restores ATP/ADP ratios in the short run and ultimately induces TXNIP protein production to suppress glucose uptake once energy homeostasis is reestablished. PMID:23453806

  18. Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane

    Science.gov (United States)

    Pohlman, John W.; Greinert, Jens; Ruppel, Carolyn; Silyakova, Anna; Vielstädte, Lisa; Casso, Michael; Mienert, Jürgen; Bünz, Stefan

    2017-05-01

    Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (biological uptake of carbon dioxide (CO2) has the potential to offset the positive warming potential of emitted methane, a process that has not received detailed consideration for these settings. Continuous sea-air gas flux data collected over a shallow ebullitive methane seep field on the Svalbard margin reveal atmospheric CO2 uptake rates (-33,300 ± 7,900 μmol m-2ṡd-1) twice that of surrounding waters and ˜1,900 times greater than the diffusive sea-air methane efflux (17.3 ± 4.8 μmol m-2ṡd-1). The negative radiative forcing expected from this CO2 uptake is up to 231 times greater than the positive radiative forcing from the methane emissions. Surface water characteristics (e.g., high dissolved oxygen, high pH, and enrichment of 13C in CO2) indicate that upwelling of cold, nutrient-rich water from near the seafloor accompanies methane emissions and stimulates CO2 consumption by photosynthesizing phytoplankton. These findings challenge the widely held perception that areas characterized by shallow-water methane seeps and/or strongly elevated sea-air methane flux always increase the global atmospheric greenhouse gas burden.

  19. Tillage and nitrogen fertilization enhanced belowground carbon allocation and plant nitrogen uptake in a semi-arid canola crop-soil system.

    Science.gov (United States)

    Sarker, Jharna Rani; Singh, Bhupinder Pal; He, Xinhua; Fang, Yunying; Li, Guangdi D; Collins, Damian; Cowie, Annette L

    2017-09-06

    Carbon (C) and nitrogen (N) allocation and assimilation are coupled processes, likely influencing C accumulation, N use efficiency and plant productivity in agro-ecosystems. However, dynamics and responses of these processes to management practices in semi-arid agro-ecosystems are poorly understood. A field-based 13CO2 and urea-15N pulse labelling experiment was conducted to track how C and N allocation and assimilation during canola growth from flowering to maturity were affected by short-term (2-year) tillage (T) and no-till (NT) with or without 100 kg urea-N ha-1 (T-0, T-100, NT-0, NT-100) on a Luvisol in an Australian semi-arid region. The T-100 caused greater (P < 0.05) belowground C allocation and higher (P < 0.05) translocation of soil N to shoots and seeds, compared to other treatments. Microbial N uptake was rapid and greatest in the fertilized (cf. non-fertilized) treatments, followed by a rapid release of microbial immobilized N, thus increasing N availability for plant uptake. In contrast, management practices had insignificant impact on soil C and N stocks, aggregate stability, microbial biomass, and 13C retention in aggregate-size fractions. In conclusion, tillage and N fertilization increased belowground C allocation and crop N uptake and yield, possibly via enhancing root-microbial interactions, with minimal impact on soil properties.

  20. Experimental warming of a mountain tundra increases soil CO2 effluxes and enhances CH4 and N2O uptake at Changbai Mountain, China.

    Science.gov (United States)

    Zhou, Yumei; Hagedorn, Frank; Zhou, Chunliang; Jiang, Xiaojie; Wang, Xiuxiu; Li, Mai-He

    2016-02-16

    Climatic warming is expected to particularly alter greenhouse gas (GHG) emissions from soils in cold ecosystems such as tundra. We used 1 m(2) open-top chambers (OTCs) during three growing seasons to examine how warming (+0.8-1.2 °C) affects the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from alpine tundra soils. Results showed that OTC warming increased soil CO2 efflux by 141% in the first growing season and by 45% in the second and third growing season. The mean CH4 flux of the three growing seasons was -27.6 and -16.7 μg CH4-C m(-2)h(-1) in the warmed and control treatment, respectively. Fluxes of N2O switched between net uptake and emission. Warming didn't significantly affect N2O emission during the first and the second growing season, but stimulated N2O uptake in the third growing season. The global warming potential of GHG was clearly dominated by soil CO2 effluxes (>99%) and was increased by the OTC warming. In conclusion, soil temperature is the main controlling factor for soil respiration in this tundra. Climate warming will lead to higher soil CO2 emissions but also to an enhanced CH4 uptake with an overall increase of the global warming potential for tundra.

  1. Drimane-type Sesquiterpene Coumarins from Ferula gummosa Fruits Enhance Doxorubicin Uptake in Doxorubicin-resistant Human Breast Cancer Cell Line

    Directory of Open Access Journals (Sweden)

    Mehrdad Iranshahi

    2014-04-01

    Full Text Available Multidrug resistance (MDR is the main cause of failure in the chemotherapy of cancer patients. The present study aimed to evaluate the effects of sesquiterpene coumarins of Ferula gummosa fruits on P-glycoprotein (P-gp–mediated MDR. Drimane-type sesquiterpene coumarins from the fruits of F. gummosa were extracted with dichloromethane and subjected to column chromatography. The effects of the isolated compounds on P-gp–mediated MDR were evaluated in the breast cancer cell line MCF-7 which shows high resistance to doxoribicin (MCF-7/Dox. Phytochemical investigation of dichloromethane extract of F. gummosa fruits resulted in three sesquiterpene coumarins including conferone (1, mogoltacin (2, and feselol (3. The structures of these compounds were confirmed by 1D and 2D Nuclear Magnetic Resonance (NMR spectroscopy. Exposure of cells to conferone, mogoltacin, feselol, and verapamil (positive control enhanced doxorubicin uptake by MCF-7/Dox cells. This effect was dose dependent, but varied with the structure of the chemical. At 25 μM, all the tested sesquiterpene coumarins restored at least 50% of the reference uptake (uptake by sensitive cells; but at 10 μM, their potency varied where conferone showed the highest potency and feselol showed the lowest potency. Conferone, mogoltacin, and feselol from F. gummosa suppress P-gp–mediated drug efflux in highly resistant human breast cancer cells.

  2. Structural Modification on the Lys Linker Enhanced Tumor to Kidney Uptake Ratios of Tc-99m-Labeled RGD-Conjugated Alpha-MSH Hybrid Peptides

    Science.gov (United States)

    Yang, Jianquan; Lu, Jie; Miao, Yubin

    2012-01-01

    The purpose of this study was to examine whether the structural modification on the positively-charged Lys linker could reduce the kidney uptake of 99mTc-labeled Arg-Gly-Asp (RGD)-conjugated alpha-melanocyte stimulating hormone (α-MSH) hybrid peptides. The RGD motif {cyclic(Arg-Gly-Asp-DTyr-Asp)} was coupled to [Cys3,4,10, D-Phe7, Arg11]α-MSH3–13 {(Arg11)CCMSH} through a neutral Glycine linker to eliminate the positively-charged amino side chain of Lys linker, or without linker to - delete the Lys linker. The receptor binding affinity of RGD-Gly-(Arg11)CCMSH and RGD-(Arg11)CCMSH was determined in B16/F1 melanoma cells. The melanoma targeting and imaging properties of 99mTc-RGD-Gly-(Arg11)CCMSH and 99mTc-RGD-(Arg11)CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The structural modification on the Lys linker retained low nanomolar receptor binding affinity of RGD-Gly-(Arg11)CCMSH and RGD-(Arg11)CCMSH (1.5 and 1.0 nM, respectively). The structural modification on the Lys linker dramatically decreased the renal uptake of 99mTc-RGD-Gly-(Arg11)CCMSH and 99mTc-RGD-(Arg11)CCMSH by 79% and 77% at 4 h post-injection compared to 99mTc-RGD-Lys-(Arg11)CCMSH. 99mTc-RGD-(Arg11)CCMSH displayed higher melanoma uptake (16.12 ± 3.09% ID/g) than 99mTc-RGD-Gly-(Arg11)CCMSH (11.50 ± 1.01% ID/g) at 2 post-injection. The tumor uptake of 99mTc-RGD-(Arg11)CCMSH was 1.4 times the tumor uptake of 99mTc-RGD-Gly-(Arg11)CCMSH at 2 post-injection. Dramatically enhanced tumor to kidney uptake ratio of 99mTc-RGD-(Arg11)CCMSH suggests that 188Re-RGD-(Arg11)CCMSH may behave in a similar fashion warranting future evaluation for melanoma treatment. PMID:22452443

  3. Structural modification on the Lys linker enhanced tumor to kidney uptake ratios of 99mTc-labeled RGD-conjugated α-MSH hybrid peptides.

    Science.gov (United States)

    Yang, Jianquan; Lu, Jie; Miao, Yubin

    2012-05-07

    The purpose of this study was to examine whether the structural modification on the positively charged Lys linker could reduce the kidney uptake of (99m)Tc-labeled Arg-Gly-Asp (RGD)-conjugated α-melanocyte stimulating hormone (α-MSH) hybrid peptides. The RGD motif {cyclic(Arg-Gly-Asp-D-Tyr-Asp)} was coupled to [Cys(3,4,10), D-Phe(7), Arg(11)]α-MSH(3-13) {(Arg(11))CCMSH} through a neutral glycine linker to eliminate the positively charged amino side chain of the Lys linker or without a linker to delete the Lys linker. The receptor binding affinity of RGD-Gly-(Arg(11))CCMSH and RGD-(Arg(11))CCMSH was determined in B16/F1 melanoma cells. The melanoma targeting and imaging properties of (99m)Tc-RGD-Gly-(Arg(11))CCMSH and (99m)Tc-RGD-(Arg(11))CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The structural modification on the Lys linker retained a low nanomolar receptor binding affinity of RGD-Gly-(Arg(11))CCMSH and RGD-(Arg(11))CCMSH (1.5 and 1.0 nM, respectively). The structural modification on the Lys linker dramatically decreased the renal uptake of (99m)Tc-RGD-Gly-(Arg(11))CCMSH and (99m)Tc-RGD-(Arg(11))CCMSH by 79% and 77% at 4 h postinjection compared to (99m)Tc-RGD-Lys-(Arg(11))CCMSH. (99m)Tc-RGD-(Arg(11))CCMSH displayed a higher melanoma uptake (16.12 ± 3.09% ID/g) than (99m)Tc-RGD-Gly-(Arg(11))CCMSH (11.50 ± 1.01% ID/g) at 2 postinjection. The tumor uptake of (99m)Tc-RGD-(Arg(11))CCMSH was 1.4 times the tumor uptake of (99m)Tc-RGD-Gly-(Arg(11))CCMSH at 2 postinjection. A dramatically enhanced tumor-to-kidney uptake ratio of (99m)Tc-RGD-(Arg(11))CCMSH suggests that (188)Re-RGD-(Arg(11))CCMSH may behave in a similar fashion warranting future evaluation for melanoma treatment.

  4. Role of thymidine phosphorylase in Fas-induced apoptosis.

    Science.gov (United States)

    Mori, S; Takao, S; Ikeda, R; Noma, H; Mataki, Y; Wang, X; Akiyama, S; Aiko, T

    2001-12-01

    Thymidine phosphorylase (TP) has chemotactic and angiogenic activity in vitro, and it promotes tumor growth and inhibits apoptosis in vivo. It plays a key role in the invasiveness and metastasis of TP-expressing solid tumors. KB/TP cells transfected with a TP cDNA have been shown to be resistant to hypoxia-induced apoptosis, suggesting that TP has effects on tumor growth and cell death independent of its effects on angiogenesis. However, the mechanisms of cell death inhibition by TP are unknown. In the present study, we demonstrate that caspase-8 is cleaved in control transfectant KB cells early on during Fas-induced apoptosis. Caspase-8 activation leads to the loss of mitochondrial membrane potential, followed by the release of cytochrome c, the activation of caspase-3, and apoptosis. In contrast, Fas-induced caspase-8 cleavage is inhibited in KB/TP cells, which lead to inhibition of the downstream apoptotic cascade and inhibition of apoptosis. These findings indicate that TP plays an important role in intracellular apoptotic signal transduction in the Fas-induced apoptotic pathway. Therefore, inhibition of TP may suppress the progression of TP-overexpressing solid tumors by inducing apoptosis.

  5. Extending Thymidine Kinase Activity to the Catalytic Repertoire of Human Deoxycytidine Kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hazra, Saugata; Sabini, Eliszbetta; Ort, Stephan; Konrad, Manfred; Lavie, Arnon; (UIC); (MXPL-G)

    2009-03-04

    Salvage of nucleosides in the cytosol of human cells is carried out by deoxycytidine kinase (dCK) and thymidine kinase 1 (TK1). Whereas TK1 is only responsible for thymidine phosphorylation, dCK is capable of converting dC, dA, and dG into their monophosphate forms. Using structural data on dCK, we predicted that select mutations at the active site would, in addition to making the enzyme faster, expand the catalytic repertoire of dCK to include thymidine. Specifically, we hypothesized that steric repulsion between the methyl group of the thymine base and Arg104 is the main factor preventing the phosphorylation of thymidine by wild-type dCK. Here we present kinetic data on several dCK variants where Arg104 has been replaced by select residues, all performed in combination with the mutation of Asp133 to an alanine. We show that several hydrophobic residues at position 104 endow dCK with thymidine kinase activity. Depending on the exact nature of the mutations, the enzyme's substrate preference is modified. The R104M-D133A double mutant is a pyrimidine-specific enzyme due to large K{sub m} values with purines. The crystal structure of the double mutant R104M-D133A in complex with the L-form of thymidine supplies a structural explanation for the ability of this variant to phosphorylate thymidine and thymidine analogs. The replacement of Arg104 by a smaller residue allows L-dT to bind deeper into the active site, making space for the C5-methyl group of the thymine base. The unique catalytic properties of several of the mutants make them good candidates for suicide-gene/protein-therapy applications.

  6. Early assessment of therapy response in malignant lymphoma with the thymidine analogue [18F]FLT.

    Science.gov (United States)

    Buck, Andreas K; Kratochwil, Clemens; Glatting, Gerhard; Juweid, Malik; Bommer, Martin; Tepsic, Djurdja; Vogg, Andreas T J; Mattfeldt, Torsten; Neumaier, Bernd; Möller, Peter; Reske, Sven N

    2007-11-01

    The aim of this study was to determine whether the thymidine analogue 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) is adequate for early evaluation of the response of malignant lymphoma to antiproliferative treatment in a mouse xenotransplant model. Immunodeficient mice bearing a follicular lymphoma xenotransplant were treated with high-dose chemotherapy (cyclophosphamide, n = 10), immunotherapy (CD20 mAb, ibritumomab-tiuxetan, n = 10) or radioimmunotherapy ([(90)Y]CD20 mAb, Zevalin, n = 10). Forty-eight hours after treatment, antiproliferative effects were assessed with [(18)F]FLT. Ninety minutes after i.v. injection of 5-10 MBq [(18)F]FLT, mice were sacrificed and radioactivity within the tumour and normal organs was measured using a gamma counter and calculated as % ID/g. The proliferation fraction in tissue samples derived from treated and untreated tumours was evaluated by Ki-67 immunohistochemistry, which served as the reference for proliferative activity. In untreated lymphoma, the mean proliferation fraction was 83.6%. After chemotherapy, the mean proliferation fraction decreased to 39.3% (p = 0.0001), after immunotherapy to 77.6% (p = 0.0078) and after radioimmunotherapy to 78.8% (p = 0.014). In none of the animals was a significant change in tumour size observed. In untreated lymphoma, tumoural [(18)F]FLT uptake was 5.4% ID/g, after chemotherapy it was 1.5% (p = 0.0005), after immunotherapy, 3.9% (non-significant), and after radioimmunotherapy, 5.8% (non-significant). In a lymphoma xenotransplant model, [(18)F]FLT detects early antiproliferative drug activity before changes in tumour size are visible. These findings further support the use of [(18)F]FLT-PET for imaging early response to treatment in malignant lymphoma.

  7. Inactivation of uptake hydrogenase leads to enhanced and sustained hydrogen production with high nitrogenase activity under high light exposure in the cyanobacterium Anabaena siamensis TISTR 8012

    Directory of Open Access Journals (Sweden)

    Khetkorn Wanthanee

    2012-10-01

    Full Text Available Abstract Background Biohydrogen from cyanobacteria has attracted public interest due to its potential as a renewable energy carrier produced from solar energy and water. Anabaena siamensis TISTR 8012, a novel strain isolated from rice paddy field in Thailand, has been identified as a promising cyanobacterial strain for use as a high-yield hydrogen producer attributed to the activities of two enzymes, nitrogenase and bidirectional hydrogenase. One main obstacle for high hydrogen production by A. siamensis is a light-driven hydrogen consumption catalyzed by the uptake hydrogenase. To overcome this and in order to enhance the potential for nitrogenase based hydrogen production, we engineered a hydrogen uptake deficient strain by interrupting hupS encoding the small subunit of the uptake hydrogenase. Results An engineered strain lacking a functional uptake hydrogenase (∆hupS produced about 4-folds more hydrogen than the wild type strain. Moreover, the ∆hupS strain showed long term, sustained hydrogen production under light exposure with 2–3 folds higher nitrogenase activity compared to the wild type. In addition, HupS inactivation had no major effects on cell growth and heterocyst differentiation. Gene expression analysis using RT-PCR indicates that electrons and ATP molecules required for hydrogen production in the ∆hupS strain may be obtained from the electron transport chain associated with the photosynthetic oxidation of water in the vegetative cells. The ∆hupS strain was found to compete well with the wild type up to 50 h in a mixed culture, thereafter the wild type started to grow on the relative expense of the ∆hupS strain. Conclusions Inactivation of hupS is an effective strategy for improving biohydrogen production, in rates and specifically in total yield, in nitrogen-fixing cultures of the cyanobacterium Anabaena siamensis TISTR 8012.

  8. Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane

    Science.gov (United States)

    Greinert, Jens; Silyakova, Anna; Vielstädte, Lisa; Casso, Michael; Mienert, Jürgen; Bünz, Stefan

    2017-01-01

    Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (methane released from the seafloor may reach the atmosphere and potentially amplify global warming. On the other hand, biological uptake of carbon dioxide (CO2) has the potential to offset the positive warming potential of emitted methane, a process that has not received detailed consideration for these settings. Continuous sea−air gas flux data collected over a shallow ebullitive methane seep field on the Svalbard margin reveal atmospheric CO2 uptake rates (−33,300 ± 7,900 μmol m−2⋅d−1) twice that of surrounding waters and ∼1,900 times greater than the diffusive sea−air methane efflux (17.3 ± 4.8 μmol m−2⋅d−1). The negative radiative forcing expected from this CO2 uptake is up to 231 times greater than the positive radiative forcing from the methane emissions. Surface water characteristics (e.g., high dissolved oxygen, high pH, and enrichment of 13C in CO2) indicate that upwelling of cold, nutrient-rich water from near the seafloor accompanies methane emissions and stimulates CO2 consumption by photosynthesizing phytoplankton. These findings challenge the widely held perception that areas characterized by shallow-water methane seeps and/or strongly elevated sea−air methane flux always increase the global atmospheric greenhouse gas burden. PMID:28484018

  9. Protein corona formation in bronchoalveolar fluid enhances diesel exhaust nanoparticle uptake and pro-inflammatory responses in macrophages.

    Science.gov (United States)

    Shaw, Catherine A; Mortimer, Gysell M; Deng, Zhou J; Carter, Edwin S; Connell, Shea P; Miller, Mark R; Duffin, Rodger; Newby, David E; Hadoke, Patrick W F; Minchin, Rodney F

    2016-09-01

    In biological fluids nanoparticles bind a range of molecules, particularly proteins, on their surface. The resulting protein corona influences biological activity and fate of nanoparticle in vivo. Corona composition is often determined by the biological milieu encountered at the entry portal into the body, and, can therefore, depend on the route of exposure to the nanoparticle. For environmental nanoparticles where exposure is by inhalation, this will be lung lining fluid. This study examined plasma and bronchoalveolar fluid (BALF) protein binding to engineered and environmental nanoparticles. We hypothesized that protein corona on nanoparticles would influence nanoparticle uptake and subsequent pro-inflammatory biological response in macrophages. All nanoparticles bound plasma and BALF proteins, but the profile of bound proteins varied between nanoparticles. Focusing on diesel exhaust nanoparticles (DENP), we identified proteins bound from plasma to include fibrinogen, and those bound from BALF to include albumin and surfactant proteins A and D. The presence on DENP of a plasma-derived corona or one of purified fibrinogen failed to evoke an inflammatory response in macrophages. However, coronae formed in BALF increased DENP uptake into macrophages two fold, and increased nanoparticulate carbon black (NanoCB) uptake fivefold. Furthermore, a BALF-derived corona increased IL-8 release from macrophages in response to DENP from 1720 ± 850 pg/mL to 5560 ± 1380 pg/mL (p = 0.014). These results demonstrate that the unique protein corona formed on nanoparticles plays an important role in determining biological reactivity and fate of nanoparticle in vivo. Importantly, these findings have implications for the mechanism of detrimental properties of environmental nanoparticles since the principle route of exposure to such particles is via the lung.

  10. Bile enhances glucose uptake, reduces permeability, and modulates effects of lectins, trypsin inhibitors and saponins on intestinal tissue.

    Science.gov (United States)

    Bakke, Anne Marie; Chikwati, Elvis M; Venold, Fredrik F; Sahlmann, Christian; Holm, Halvor; Penn, Michael H; Oropeza-Moe, Marianne; Krogdahl, Åshild

    2014-02-01

    Antinutritional factors (ANFs) can disrupt digestive and other intestinal functions. ANFs in soybean meal (SBM) are implicated in proliferative and inflammatory responses in the intestine of various (functionally) monogastric animals, including Atlantic salmon (Salmo salar L.). The goal of the current study was to investigate the effect of ex vivo exposure of mid and distal intestinal tissue of salmon to soybean saponins (SAP), lectin (LEC) and Kunitz' trypsin inhibitor (KTI), singly and in combination, on epithelial function, as assessed by measuring in vitro glucose uptake pathways along a glucose concentration gradient. As solubilization of SAP in the calcium-containing Ringer's solution was problematic but resolved with the addition of a physiological concentration of bile collected from the gall bladder of salmon, an evaluation of bile effects became an added element. Results indicated that bile increased baseline glucose absorption and possibly transport, and also had a protective effect on the epithelial barrier, at least partially due to taurocholate. Compared to controls, tissues exposed to LEC+bile, KTI+bile and LEC+KTI+bile exhibited increased glucose uptake at the higher glucose concentrations, apparently due to markedly increased tissue permeability. Addition of SAP, however, attenuated the response, possibly by binding bile components. SAP+bile, also in combination with LEC and/or KTI, as well as LEC, KTI and LEC+KTI without bile often reduced transcellular glucose uptake pathways, while maintaining low tissue permeability. SAP+LEC+KTI+bile, LEC and KTI caused the most marked reductions. The distal intestine was more affected, reflecting the restriction of in vivo SBM-induced inflammatory changes to this region. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Coating Nanoparticles with Plant-Produced Transferrin-Hydrophobin Fusion Protein Enhances Their Uptake in Cancer Cells

    DEFF Research Database (Denmark)

    Reuter, Lauri J.; Shahbazi, Mohammad-Ali; Makila, Ermei M.

    2017-01-01

    to a surfactant phase in an aqueous two-phase system, and the transferrin moiety was able to reversibly bind iron. Coating porous silicon nanoparticles with the fusion protein resulted in uptake of the nanoparticles in human cancer cells. This study provides a proof-of concept for the functionalization......The encapsulation of drugs to nanoparticles may offer a solution for targeted delivery. Here, we set out to engineer a self assembling targeting ligand by combining the functional properties of human transferrin and fungal hydrophobins in a single fusion protein. We showed that human transferrin...... of hydrophobin coatings with transferrin as a targeting ligand....

  12. Modifying Cationic Liposomes with Cholesteryl-PEG Prevents Their Aggregation in Human Urine and Enhances Cellular Uptake by Bladder Cancer Cells.

    Science.gov (United States)

    Nakamura, Takashi; Noma, Yosuke; Sakurai, Yu; Harashima, Hideyoshi

    2017-01-01

    Intravesical drug delivery by cationic liposomes (Cat-LPs) represents a potent nanotechnology for enhancing therapeutic effects against bladder disorders. However, preventing the aggregation of Cat-LPs in urine poses a significant barrier. We report on an examination of the effect of modifying liposomes with polyethylene glycol (PEG) lipids to prevent Cat-LPs from aggregating in human urine. Although Cat-LPs underwent significant aggregation in human urine, introducing 5 mol% of PEG2k lipid or 2 mol% of PEG5k lipid completely inhibited the aggregation of the Cat-LPs. When 2 mol% of PEG2k lipids were introduced, the lipid structures of 1,2-distearoly-sn-glycero-3-phosphoethanolamine (DSPE) and 1,2-distearoyl-sn-glycerol (DSG) greatly prevented aggregation compared with cholesterol. By contrast, when Cat-LPs, after incubation in urine, were exposed to bladder cancer cells, only introducing cholesteryl-PEG into the Cat-LPs showed a significant enhancement in cellular uptake. These results offer the potential for incorporating cholesteryl-PEG into Cat-LPs for achieving both stability in urine and effective cellular uptake.

  13. Enhanced Brain Delivery of Dimethyl Fumarate Employing Tocopherol-Acetate-Based Nanolipidic Carriers: Evidence from Pharmacokinetic, Biodistribution, and Cellular Uptake Studies.

    Science.gov (United States)

    Kumar, Pramod; Sharma, Gajanand; Kumar, Rajendra; Malik, Ruchi; Singh, Bhupinder; Katare, O P; Raza, Kaisar

    2017-04-19

    Dimethyl fumarate (DMF) is an approved drug for the management of relapsing multiple sclerosis. Despite efficacy, DMF is also reported to be a challenging drug owing to concerns like gastrointestinal tract flushing, multiple dosing, lower brain permeability, less patient compliance, and economic hurdles. The present study aims to develop DMF-tocopherol acetate nanolipidic carrier (NLCs) to enhance brain permeability and improve the gastric tolerance. The developed DMF-tocopherol acetate NLCs offered an average size of 69.70 nm, PDI of 0.317, and a zeta potential of -9.71 mV. Higher drug entrapment (90.12%) and drug loading (20.13%) assured controlled drug release behavior both in gastric and intestinal pH. Cellular uptake studies on Caco-2 and SH-SY5Y monolayers confirmed better intestinal absorption and neuronal uptake of the developed system, which was further corroborated by the pharmacokinetic and biodistribution studies. The oral bioavailability was enhanced by 4.09 times and brain availability was substantially improved vis-à-vis plain drug. The findings are promising and offer preclinical evidence for better brain availability of DMF, which can be exploited in the better management of diseases like multiple sclerosis.

  14. The uptake transporter OATP8 expression decreases during multistep hepatocarcinogenesis: correlation with gadoxetic acid enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kitao, Azusa; Matsui, Osamu; Yoneda, Norihide; Kozaka, Kazuto; Shinmura, Rieko; Koda, Wataru; Kobayashi, Satoshi; Gabata, Toshifumi [Kanazawa University Graduate School of Medical Science, Department of Radiology, Kanazawa (Japan); Zen, Yoh [Kanazawa University Graduate School of Medical Science, Human Pathology, Kanazawa (Japan); King' s College Hospital, Institute of Liver Studies, London (United Kingdom); Yamashita, Tatsuya; Kaneko, Shuichi [Kanazawa University Graduate School of Medical Science, Gastroenterology, Kanazawa (Japan); Nakanuma, Yasuni [Kanazawa University Graduate School of Medical Science, Human Pathology, Kanazawa (Japan)

    2011-10-15

    To clarify the changes in organic anion-transporting polypeptide 8 (OATP8) expression and enhancement ratio on gadoxetic acid-enhanced MR imaging in hepatocellular nodules during multistep hepatocarcinogenesis. In imaging analysis, we focused on 71 surgically resected hepatocellular carcinomas (well, moderately and poorly differentiated HCCs) and 1 dysplastic nodule (DN). We examined the enhancement ratio in the hepatobiliary phase of gadoxetic acid enhanced MR imaging [(1/postcontrast T1 value-1/precontrast T1 value)/(1/precontrast T1 value)], then analysed the correlation among the enhancement ratio, tumour differentiation grade and intensity of immunohistochemical OATP8 expression. In pathological analysis, we focused on surgically resected 190 hepatocellular nodules: low-grade DNs, high-grade DNs, early HCCs, well-differentiated, moderately differentiated and poorly differentiated HCCs, including cases without gadoxetic acid-enhanced MR imaging. We evaluated the correlation between the immunohistochemical OATP8 expression and the tumour differentiation grade. The enhancement ratio of HCCs decreased in accordance with the decline in tumour differentiation (P < 0.0001, R = 0.28) and with the decline of OATP8 expression (P < 0.0001, R = 0.81). The immunohistochemical OATP8 expression decreased from low-grade DNs to poorly differentiated HCCs (P < 0.0001, R = 0.15). The immunohistochemical expression of OATP8 significantly decreases during multistep hepatocarcinogenesis, which may explain the decrease in enhancement ratio on gadoxetic acid-enhanced MR imaging. (orig.)

  15. Reduction of glucose uptake through inhibition of hexose transporters and enhancement of their endocytosis by methylglyoxal in Saccharomyces cerevisiae.

    Science.gov (United States)

    Yoshida, Aya; Wei, Dandan; Nomura, Wataru; Izawa, Shingo; Inoue, Yoshiharu

    2012-01-02

    Diabetes mellitus is characterized by an impairment of glucose uptake even though blood glucose levels are increased. Methylglyoxal is derived from glycolysis and has been implicated in the development of diabetes mellitus, because methylglyoxal levels in blood and tissues are higher in diabetic patients than in healthy individuals. However, it remains to be elucidated whether such factors are a cause, or consequence, of diabetes. Here, we show that methylglyoxal inhibits the activity of mammalian glucose transporters using recombinant Saccharomyces cerevisiae cells genetically lacking all hexose transporters but carrying cDNA for human GLUT1 or rat GLUT4. We found that methylglyoxal inhibits yeast hexose transporters also. Glucose uptake was reduced in a stepwise manner following treatment with methylglyoxal, i.e. a rapid reduction within 5 min, followed by a slow and gradual reduction. The rapid reduction was due to the inhibitory effect of methylglyoxal on hexose transporters, whereas the slow and gradual reduction seemed due to endocytosis, which leads to a decrease in the amount of hexose transporters on the plasma membrane. We found that Rsp5, a HECT-type ubiquitin ligase, is responsible for the ubiquitination of hexose transporters. Intriguingly, Plc1 (phospholipase C) negatively regulated the endocytosis of hexose transporters in an Rsp5-dependent manner, although the methylglyoxal-induced endocytosis of hexose transporters occurred irrespective of Plc1. Meanwhile, the internalization of hexose transporters following treatment with methylglyoxal was delayed in a mutant defective in protein kinase C.

  16. Additive effects due to biochar and endophyte application enable soybean to enhance nutrient uptake and modulate nutritional parameters.

    Science.gov (United States)

    Waqas, Muhammad; Kim, Yoon-Ha; Khan, Abdul Latif; Shahzad, Raheem; Asaf, Sajjad; Hamayun, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Lee, In-Jung

    We studied the effects of hardwood-derived biochar (BC) and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean (Glycine max (L.) Merr.) with respect to basic, macro- and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC+G. geotrichum-treated soybean plants. In comparison, the uptakes of macro- and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC+G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents.

  17. Additive effects due to biochar and endophyte application enable soybean to enhance nutrient uptake and modulate nutritional parameters* #

    Science.gov (United States)

    Waqas, Muhammad; Kim, Yoon-Ha; Khan, Abdul Latif; Shahzad, Raheem; Asaf, Sajjad; Hamayun, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Lee, In-Jung

    2017-01-01

    We studied the effects of hardwood-derived biochar (BC) and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean (Glycine max (L.) Merr.) with respect to basic, macro-and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC+G. geotrichum-treated soybean plants. In comparison, the uptakes of macro-and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC+G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents. PMID:28124840

  18. Coating Nanoparticles with Plant-Produced Transferrin-Hydrophobin Fusion Protein Enhances Their Uptake in Cancer Cells.

    Science.gov (United States)

    Reuter, Lauri J; Shahbazi, Mohammad-Ali; Mäkilä, Ermei M; Salonen, Jarno J; Saberianfar, Reza; Menassa, Rima; Santos, Hélder A; Joensuu, Jussi J; Ritala, Anneli

    2017-06-21

    The encapsulation of drugs to nanoparticles may offer a solution for targeted delivery. Here, we set out to engineer a self-assembling targeting ligand by combining the functional properties of human transferrin and fungal hydrophobins in a single fusion protein. We showed that human transferrin can be expressed in Nicotiana benthamiana plants as a fusion with Trichoderma reesei hydrophobins HFBI, HFBII, or HFBIV. Transferrin-HFBIV was further expressed in tobacco BY-2 suspension cells. Both partners of the fusion protein retained their functionality; the hydrophobin moiety enabled migration to a surfactant phase in an aqueous two-phase system, and the transferrin moiety was able to reversibly bind iron. Coating porous silicon nanoparticles with the fusion protein resulted in uptake of the nanoparticles in human cancer cells. This study provides a proof-of-concept for the functionalization of hydrophobin coatings with transferrin as a targeting ligand.

  19. Ligand Torsion Triggered Two Robust Fe-Tetratopic Carboxylate Frameworks with Enhanced Gas Uptake and Separation Performance.

    Science.gov (United States)

    Zhang, Jian-Wei; Hu, Man-Cheng; Li, Shu-Ni; Jiang, Yu-Cheng; Zhai, Quan-Guo

    2017-05-11

    By regulating the tetratopic carboxylate ligands, two robust Fe-MOFs (MOF=Metal-organic framework) comprising trigonal prismatic building blocks under a DMA/DMSO/HBF4 solvent system, namely, [(CH3 )2 NH2 ][Fe(II)3 (OH)(BPTC)1.5 (DMSO)3 ] (SNNU-60) and [Fe(III) Fe(II)2 (OH)(ABTC)1.5 (DMSO)3 ] (SNNU-61) (BPTC=3,3',5,5'-biphenyltetracarboxylic acid, ABTC=3,3',5,5'-azobenzenetetracarboxylic acid, SNNU=Shaanxi Normal University) have been successfully synthesized. The torsions between the benzene groups of the ligands result in two MOFs exhibiting completely different (4,6)-connected frameworks, which represent the only two MOF types constructed by [M3 (O/OH)(COO)6 ] trimeric building units and quadrilateral tetratopic carboxylate linkers until now. The robust Fe-MOFs SNNU-60 and SNNU-61 both exhibit high thermal/chemical stability, permanent microporosity, and excellent gas uptake capability for H2 , CO2 , C2 H2 , and C2 H4 under 1 bar. SNNU-60 in particular displays very high C2 H2 capture under low pressure (85 cm(3)  cm(-3) at 0.15 bar and 298 K), which is among the top C2 H2 uptake MOF materials. Also, these two Fe-MOFs display high separation for CO2 and C2 -hydrocarbons over CH4 . Significantly, thanks to the high stability, suitable pore size, open Fe sites, and ion skeleton, SNNU-60 has extremely high C2 H2 /CH4 selectivity (83.6, 298 K), which surpasses most MOFs reported so far under the same conditions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Hepatic intestinal uptake and release of catecholamines in alcoholic cirrhosis. Evidence of enhanced hepatic intestinal sympathetic nervous activity

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Ring-Larsen, H; Christensen, N J

    1987-01-01

    spillover represents a minimum value. Our results indicate that the augmented circulating catecholamines in cirrhosis do not result from diminished removal but are contributed to from increased sympathetic nervous activity in the hepatic intestinal area (enhanced mesenteric sympathetic nervous activity)....

  1. Repeatability of quantitative FDG-PET/CT and contrast-enhanced CT in recurrent ovarian carcinoma: test-retest measurements for tumor FDG uptake, diameter, and volume.

    Science.gov (United States)

    Rockall, Andrea G; Avril, Norbert; Lam, Raymond; Iannone, Robert; Mozley, P David; Parkinson, Christine; Bergstrom, Donald; Sala, Evis; Sarker, Shah-Jalal; McNeish, Iain A; Brenton, James D

    2014-05-15

    Repeatability of baseline FDG-PET/CT measurements has not been tested in ovarian cancer. This dual-center, prospective study assessed variation in tumor 2[18F]fluoro-2-deoxy-D-glucose (FDG) uptake, tumor diameter, and tumor volume from sequential FDG-PET/CT and contrast-enhanced computed tomography (CECT) in patients with recurrent platinum-sensitive ovarian cancer. Patients underwent two pretreatment baseline FDG-PET/CT (n = 21) and CECT (n = 20) at two clinical sites with different PET/CT instruments. Patients were included if they had at least one target lesion in the abdomen with a standardized uptake value (SUV) maximum (SUVmax) of ≥ 2.5 and a long axis diameter of ≥ 15 mm. Two independent reading methods were used to evaluate repeatability of tumor diameter and SUV uptake: on site and at an imaging clinical research organization (CRO). Tumor volume reads were only performed by CRO. In each reading set, target lesions were independently measured on sequential imaging. Median time between FDG-PET/CT was two days (range 1-7). For site reads, concordance correlation coefficients (CCC) for SUVmean, SUVmax, and tumor diameter were 0.95, 0.94, and 0.99, respectively. Repeatability coefficients were 16.3%, 17.3%, and 8.8% for SUVmean, SUVmax, and tumor diameter, respectively. Similar results were observed for CRO reads. Tumor volume CCC was 0.99 with a repeatability coefficient of 28.1%. There was excellent test-retest repeatability for FDG-PET/CT quantitative measurements across two sites and two independent reading methods. Cutoff values for determining change in SUVmean, SUVmax, and tumor volume establish limits to determine metabolic and/or volumetric response to treatment in platinum-sensitive relapsed ovarian cancer. ©2014 American Association for Cancer Research.

  2. Hypoglycemic Effect of Opuntia ficus-indica var. saboten Is Due to Enhanced Peripheral Glucose Uptake through Activation of AMPK/p38 MAPK Pathway

    Directory of Open Access Journals (Sweden)

    Kang-Hyun Leem

    2016-12-01

    Full Text Available Opuntia ficus-indica var. saboten (OFS has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, detailed mechanisms underlying hypoglycemic effects remain unclear. In this study, the mechanism underlying the hypoglycemic activity of OFS was evaluated using in vitro and in vivo systems. OFS treatment inhibited α-glucosidase activity and intestinal glucose absorption assessed by Na+-dependent glucose uptake using brush border membrane vesicles. AMP-activated protein kinase (AMPK is widely recognized as an important regulator of glucose transport in skeletal muscle, and p38 mitogen-activated protein kinase (MAPK has been proposed to be a component of AMPK-mediated signaling. In the present study, OFS dose-dependently increased glucose uptake in L6 muscle cells. The AMPK and p38 MAPK phosphorylations were stimulated by OFS, and inhibitors of AMPK (compound C and p38 MAPK (SB203580 abolished the effects of OFS. Furthermore, OFS increased glucose transporter 4 (GLUT4 translocation to the plasma membrane. OFS administration (1 g/kg and 2 g/kg body weight in db/db mice dose-dependently ameliorated hyperglycemia, hyperinsulinemia, and glucose tolerance. Insulin resistance assessed by homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were also dose-dependently improved with OFS treatment. OFS administration improved pancreatic function through increased β-cell mass in db/db mice. These findings suggest that OFS acts by inhibiting glucose absorption from the intestine and enhancing glucose uptake from insulin-sensitive muscle cells through the AMPK/p38 MAPK signaling pathway.

  3. Hypoglycemic Effect of Opuntia ficus-indica var. saboten Is Due to Enhanced Peripheral Glucose Uptake through Activation of AMPK/p38 MAPK Pathway.

    Science.gov (United States)

    Leem, Kang-Hyun; Kim, Myung-Gyou; Hahm, Young-Tae; Kim, Hye Kyung

    2016-12-09

    Opuntia ficus-indica var. saboten (OFS) has been used in traditional medicine for centuries to treat several illnesses, including diabetes. However, detailed mechanisms underlying hypoglycemic effects remain unclear. In this study, the mechanism underlying the hypoglycemic activity of OFS was evaluated using in vitro and in vivo systems. OFS treatment inhibited α-glucosidase activity and intestinal glucose absorption assessed by Na⁺-dependent glucose uptake using brush border membrane vesicles. AMP-activated protein kinase (AMPK) is widely recognized as an important regulator of glucose transport in skeletal muscle, and p38 mitogen-activated protein kinase (MAPK) has been proposed to be a component of AMPK-mediated signaling. In the present study, OFS dose-dependently increased glucose uptake in L6 muscle cells. The AMPK and p38 MAPK phosphorylations were stimulated by OFS, and inhibitors of AMPK (compound C) and p38 MAPK (SB203580) abolished the effects of OFS. Furthermore, OFS increased glucose transporter 4 (GLUT4) translocation to the plasma membrane. OFS administration (1 g/kg and 2 g/kg body weight) in db/db mice dose-dependently ameliorated hyperglycemia, hyperinsulinemia, and glucose tolerance. Insulin resistance assessed by homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were also dose-dependently improved with OFS treatment. OFS administration improved pancreatic function through increased β-cell mass in db/db mice. These findings suggest that OFS acts by inhibiting glucose absorption from the intestine and enhancing glucose uptake from insulin-sensitive muscle cells through the AMPK/p38 MAPK signaling pathway.

  4. [Influence of the thymidine phosphorylase (platelet-derived endothelial cell growth factor) on tumor angiogenesis. Catalytic activity of enzyme inhibitors].

    Science.gov (United States)

    Miszczak-Zaborska, Elzbieta; Smolarek, Monika; Bartkowiak, Jacek

    2010-01-01

    Thymidine phosphorylase, also known as platelet-derived endothelial cell growth factor, is a potent angiogenic factor. Thymidine phosphorylase is overexpressed in various human tumors and plays an important role in angiogenesis. A novel inhibitor of thymidine phosphorylase (TP), 5-chloro-6-[1-(2-iminopyrrolidinyl) methyl] uracil hydrochloride (TPI) is about 1000-fold more active than 6-amino-5-chlorouracil, one of the most potent TP inhibitors to 1999 year. Thymidine phosphorylase is also inhibited by 5'-O-trityl-inosine (KIN59) and related compounds, 2-deoxy-L-ribose and glycosides isolated from the bark of Symplocos racemosa.

  5. Dynamics of the enhanced emissions of monoterpenes and methyl salicylate, and decreased uptake of formaldehyde, by Quercus ilex leaves after application of jasmonic acid.

    Science.gov (United States)

    Filella, Iolanda; Peñuelas, Josep; Llusià, Joan

    2006-01-01

    Jasmonic acid (JA) is a signalling compound with a key role in both stress and development in plants, and is reported to elicit the emission of volatile organic compounds (VOCs). Here we studied the dynamics of such emissions and the linkage with photosynthetic rates and stomatal conductance. We sprayed JA on leaves of the Mediterranean tree species Quercus ilex and measured the photosynthetic rates, stomatal conductances, and emissions and uptake of VOCs using proton transfer reaction mass spectrometry and gas chromatography after a dark-light transition. Jasmonic acid treatment delayed the induction of photosynthesis and stomatal conductance by approx. 20 min, and decreased them 24 h after spraying. Indications were found of both stomatal and nonstomatal limitations of photosynthesis. Monoterpene emissions were enhanced (20-30%) after JA spraying. Jasmonic acid also increased methyl salicylate (MeSa) emissions (more than twofold) 1 h after treatment, although after 24 h this effect had disappeared. Formaldehyde foliar uptake decreased significantly 24 h after JA treatment. Both biotic and abiotic stresses can thus affect plant VOC emissions through their strong impact on JA levels. Jasmonic acid-mediated increases in monoterpene and MeSa emissions might have a protective role when confronting biotic and abiotic stresses.

  6. Enhancement of bactericidal activity against group B streptococci with reduced penicillin susceptibility by uptake of gentamicin into cells resulting from combination with β-lactam antibiotics.

    Science.gov (United States)

    Ebara, Yoshifumi; Morozumi, Miyuki; Sato, Mamiko; Moritoki, Nobuko; Toyofuku, Meiwa; Takata, Misako; Murata, Mitsuru; Ubukata, Kimiko; Iwata, Satoshi

    2017-05-01

    Combined effects of penicillin (PEN) and gentamicin (GM) against Streptococcus agalactiae, i.e. group B streptococci (GBS), are known to occur, but synergy has not been examined in strains with reduced PEN susceptibility, usually called PEN-resistant GBS (PRGBS). We therefore studied combined effects of β-lactam antibiotics and GM in cultures of 3 PRGBS strains belonging to serotype Ia or III that were isolated from Japanese adults with invasive infections. Killing kinetics were determined at 2-h intervals from 0 to 6 h after exposure to ampicillin (AMP) or cefotaxime (CTX) combined with GM. Concentrations of GM in bacterial cells were measured by liquid chromatography-tandem mass spectrometry. Morphologic changes after exposure to agents were observed by transmission electron microscopy. Combining AMP or CTX with GM synergistically increased bactericidal activity against PRGBS beyond that of either β-lactam alone. GM concentrations in bacterial cells increased 5- to 8-fold when GM was combined with AMP or CTX. Electron microscopically, bacterial cells showed aggregates of strands and ribosomal damage most likely reflecting enhanced GM uptake into bacterial cells. This uptake appeared to result from cell wall damage caused by β-lactam antibiotics. This study suggests that combining β-lactam antibiotics with GM might be useful against severe PRGBS infection. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  7. Tetrameric far-red fluorescent protein as a scaffold to assemble an octavalent peptide nanoprobe for enhanced tumor targeting and intracellular uptake in vivo.

    Science.gov (United States)

    Luo, Haiming; Yang, Jie; Jin, Honglin; Huang, Chuan; Fu, Jianwei; Yang, Fei; Gong, Hui; Zeng, Shaoqun; Luo, Qingming; Zhang, Zhihong

    2011-06-01

    Relatively weak tumor affinities and short retention time in vivo hinder the application of targeting peptides in tumor molecular imaging. Multivalent strategies based on various scaffolds have been utilized to improve the ability of peptide-receptor binding or extend the clearance time of peptide-based probes. Here, we use a tetrameric far-red fluorescent protein (tfRFP) as a scaffold to create a self-assembled octavalent peptide fluorescent nanoprobe (Octa-FNP) using a genetic engineering approach. The multiligand connecting, fluorophore labeling and nanostructure formation of Octa-FNP were performed in one step. In vitro studies showed Octa-FNP is a 10-nm fluorescent probe with excellent serum stability. Cellular uptake of Octa-FNP by human nasopharyngeal cancer 5-8F cells is 15-fold of tetravalent probe, ∼80-fold of monovalent probe and ∼600-fold of nulvalent tfRFP. In vivo enhanced tumor targeting and intracellular uptake of Octa-FNP were confirmed using optical imaging and Western blot analysis. It achieved extremely high contrast of Octa-FNP signal between tumor tissue and normal organs, especially seldom Octa-FNP detected in liver and spleen. Owing to easy preparation, precise structural and functional control, and multivalent effect, Octa-FNP provides a powerful tool for tumor optical molecular imaging and evaluating the targeting ability of numerous peptides in vivo.

  8. Anti-diabetic effects of Caulerpa lentillifera: stimulation of insulin secretion in pancreatic β-cells and enhancement of glucose uptake in adipocytes.

    Science.gov (United States)

    Sharma, Bhesh Raj; Rhyu, Dong Young

    2014-07-01

    To evaluate anti-diabetic effect of Caulerpa lentillifera (C. lentillifera). The inhibitory effect of C. lentillifera extract on dipeptidyl peptidase-IV and α-glucosidase enzyme was measured in a cell free system. Then, interleukin-1β and interferon-γ induced cell death and insulin secretion were measured in rat insulinoma (RIN) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit, respectively. Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting, using 3T3-L1 adipocytes. C. lentillifera extract significantly decreased dipeptidyl peptidase-IV and α-glucosidase enzyme activities, and effectively inhibited cell death and iNOS expression in interleukin-1β and interferon-γ induced RIN cells. Furthermore, C. lentillifera extract significantly enhanced insulin secretion in RIN cells and glucose transporter expression and glucose uptake in 3T3-L1 adipocytes. Thus, our results suggest that C. lentillifera could be used as a potential anti-diabetic agent.

  9. PLGA-soya lecithin based micelles for enhanced delivery of methotrexate: Cellular uptake, cytotoxic and pharmacokinetic evidences.

    Science.gov (United States)

    Singh, Anupama; Thotakura, Nagarani; Kumar, Rajendra; Singh, Bhupinder; Sharma, Gajanand; Katare, Om Prakash; Raza, Kaisar

    2017-02-01

    Biocompatible and biodegradable polymers like PLGA have revolutionized the drug delivery approaches. However, poor drug loading and substantially high lipophilicity, pave a path for further tailing of this promising agent. In this regard, PLGA was feathered with biocompatible phospholipid and polymeric micelles were developed for delivery of Methotrexate (MTX) to cancer cells. The nanocarriers (114.6nm±5.5nm) enhanced the cytotoxicity of MTX by 2.13 folds on MDA-MB-231 cells. Confocal laser scanning microscopy confirmed the increased intracellular delivery. The carrier decreased the protein binding potential and enhanced the bioavailable fraction of MTX. Pharmacokinetic studies vouched substantial enhancement in AUC and bioresidence time, promising an ideal carrier to effectively deliver the drug to the site of action. The developed nanocarriers offer potential to deliver the drug in the interiors of cancer cells in an effective manner for improved therapeutic action. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Biochar enhances the cadmium tolerance in spinach (Spinacia oleracea) through modification of Cd uptake and physiological and biochemical attributes.

    Science.gov (United States)

    Younis, Uzma; Malik, Saeed Ahmad; Rizwan, Muhammad; Qayyum, Muhammad Farooq; Ok, Yong Sik; Shah, Muhammad Hasnain Raza; Rehman, Rabia Abdur; Ahmad, Niaz

    2016-11-01

    Cadmium (Cd) has no known role in plant biology and is toxic to plants and animals. The Cd mainly accumulated in agricultural soils through anthropogenic activities, such as sewage water irrigation and phosphorus fertilization. Biochar (BC) has been proposed as an amendment to reduce metal toxicity in plants. The objective of this study was to evaluate the role of BC (cotton stick at a rate of 0, 3, and 5 %) on Cd uptake and the photosynthetic, physiological, and biochemical responses of spinach (Spinacia oleracea) grown in Cd-spiked soil (0, 25, 50, 75, and 100 mg Cd kg-1 soil). The results showed that Cd toxicity decreased growth, photosynthetic pigments, gas exchange characteristics, and amino acid and protein contents in 52-day-old spinach seedlings. The Cd treatments increased the concentrations of Cd, sugar, ascorbic acid, and malondialdehyde (MDA) in plants. The application of BC ameliorated the harmful effects of Cd in spinach plants. Under Cd stress, BC application increased the growth, photosynthesis, and protein contents and decreased Cd concentrations and MDA contents in plants. The maximum BC-mediated increase in dry biomass was about 25 % with 5 % BC application in control plants. It is concluded that BC could ameliorate Cd toxic effects in spinach through changing the physiological and biochemical attributes under Cd stress.

  11. Enhanced uptake of lactosaminated human albumin by rat hepatocarcinomas: implications for an improved chemotherapy of primary liver tumors.

    Science.gov (United States)

    Di Stefano, Giuseppina; Fiume, Luigi; Bolondi, Luigi; Lanza, Marcella; Pariali, Milena; Chieco, Pasquale

    2005-08-01

    The hepatocyte receptor for asialoglycoproteins (ASGP-R) internalizes macromolecules exposing galactosyl residues (MEGRs) which can be used as liver-addressed drug carriers. This receptor was also found on the cells of the large majority of well differentiated hepatocarcinomas (HCCs). The aim of the present experiments was to ascertain whether ASGP-R of HCCs is functionally active and these tumors can internalize higher quantities of MEGRs than extra-hepatic tissues. We injected radioactive lactosaminated human albumin (L-HSA) in rats with HCCs produced by nitroso-diethylamine and measured the radioactivity of tumors, surrounding liver, heart, intestine and kidney. L-HSA is a MEGR successfully used in humans as a hepatotropic drug carrier. The levels of radioactivity of HCCs were two to three times lower than those of surrounding liver, but several times higher than those of extra-hepatic tissues. L-HSA accumulation in the tumors mainly occurred via the ASGP-R, as indicated by the 20 times lower penetration of non-lactosaminated HSA. L-HSA uptake by the well-differentiated tumors were four times higher compared with that by the poorly differentiated forms. The present results suggest that in the chemotherapy of HCCs expressing the ASGP-R the extra-hepatic toxicity of anticancer agents can be reduced by conjugation to L-HSA.

  12. Solid Lipid Nanoparticles of Albendazole for Enhancing Cellular Uptake and Cytotoxicity against U-87 MG Glioma Cell Lines

    Directory of Open Access Journals (Sweden)

    Gregory Marslin

    2017-11-01

    Full Text Available Albendazole (ABZ is an antihelminthic drug used for the treatment of several parasitic infestations. In addition to this, there are reports on the anticancer activity of ABZ against a wide range of cancer types. However, its effect on glioma has not yet been reported. In the present study, cytotoxicity of ABZ and ABZ loaded solid lipid nanoparticles (ASLNs was tested in human glioma/astrocytoma cell line (U-87 MG. Using glyceryl trimyristate as lipid carrier and tween 80 as surfactant spherical ASLNs with an average size of 218.4 ± 5.1 nm were prepared by a combination of high shear homogenization and probe sonication methods. A biphasic in vitro release pattern of ABZ from ASLNs was observed, where 82% of ABZ was released in 24 h. In vitro cell line studies have shown that ABZ in the form of ASLNs was more cytotoxic (IC50 = 4.90 µg/mL to U-87 MG cells compared to ABZ in the free form (IC50 = 13.30 µg/mL due to the efficient uptake of the former by these cells.

  13. Stay-green alleles individually enhance grain yield in sorghum under drought by modifying canopy development and water uptake patterns.

    Science.gov (United States)

    Borrell, Andrew K; van Oosterom, Erik J; Mullet, John E; George-Jaeggli, Barbara; Jordan, David R; Klein, Patricia E; Hammer, Graeme L

    2014-08-01

    Stay-green is an integrated drought adaptation trait characterized by a distinct green leaf phenotype during grain filling under terminal drought. We used sorghum (Sorghum bicolor), a repository of drought adaptation mechanisms, to elucidate the physiological and genetic mechanisms underpinning stay-green. Near-isogenic sorghum lines (cv RTx7000) were characterized in a series of field and managed-environment trials (seven experiments and 14 environments) to determine the influence of four individual stay-green (Stg1-4) quantitative trait loci (QTLs) on canopy development, water use and grain yield under post-anthesis drought. The Stg QTL decreased tillering and the size of upper leaves, which reduced canopy size at anthesis. This reduction in transpirational leaf area conserved soil water before anthesis for use during grain filling. Increased water uptake during grain filling of Stg near-isogenic lines (NILs) relative to RTx7000 resulted in higher post-anthesis biomass production, grain number and yield. Importantly, there was no consistent yield penalty associated with the Stg QTL in the irrigated control. These results establish a link between the role of the Stg QTL in modifying canopy development and the subsequent impact on crop water use patterns and grain yield under terminal drought. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  14. Miscellaneous additives can enhance plant uptake and affect geochemical fractions of copper in a heavily polluted riparian grassland soil.

    Science.gov (United States)

    Rinklebe, Jörg; Shaheen, Sabry M

    2015-09-01

    The problem of copper (Cu) pollution in riverine ecosystems is world-wide and has significant environmental, eco-toxicological, and agricultural relevance. We assessed the suitability and effectiveness of application rate of 1% of activated charcoal, bentonite, biochar, cement kiln dust, chitosan, coal fly ash, limestone, nano-hydroxyapatite, organo-clay, sugar beet factory lime, and zeolite as soil amendments together with rapeseed as bioenergy crop as a possible remediation option for a heavily Cu polluted floodplain soil (total Cu=3041.9mgkg(-1)) that has a very high proportion of sorbed/carbonate fraction (484.6mgkg(-1)) and potential mobile fraction of Cu (1611.9mgkg(-1)). Application changed distribution of Cu among geochemical fractions: alkaline materials lead to increased carbonate bounded fraction and the acid rhizosphere zone might cause release of this Cu. Thus, mobilization of Cu and uptake of Cu by rapeseed were increased compared to the control (except for organo-clay) under the prevailing conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Benzimidazole derivative small-molecule 991 enhances AMPK activity and glucose uptake induced by AICAR or contraction in skeletal muscle

    DEFF Research Database (Denmark)

    Bultot, Laurent; Jensen, Thomas Elbenhardt; Lai, Yu-Chiang

    2016-01-01

    )- and γ (γ1, γ2, γ3)-subunits, which are uniquely distributed across different cell types. There has been keen interest in developing specific and isoform-selective AMPK-activating drugs for therapeutic use and also as research tools. Moreover, establishing ways of enhancing cellular AMPK activity would...

  16. Human carotid plaque phosphatidylcholine specifically interacts with paraoxonase 1, increases its activity, and enhances its uptake by macrophage at the expense of its binding to HDL.

    Science.gov (United States)

    Cohen, Elad; Aviram, Michael; Khatib, Soliman; Artoul, Fadi; Rabin, Asaf; Mannheim, Dalit; Karmeli, Ron; Salamon, Tal; Vaya, Jacob

    2014-11-01

    Human carotid atherosclerotic plaque is in direct contact with circulatory blood components. Thus, plaque and blood components may affect each other. The current study presents the effects of plaque chloroform:methanol (C:M) extract on the HDL-associated enzyme paraoxnase 1 (PON1). This study is part of our investigation on the mutual effects of the interactions between atherosclerotic lesions and blood components. Recombinant PON1 (rePON1) was incubated with the human carotid plaques C:M extract and PON1 activities were analyzed. Lactonase and paraoxonase activities were elevated due to C:M treatment, by 140 and by 69%, respectively. Analytical chemistry analyses revealed specific phosphatidylcholines (PCs) as the plaque active components. Tryptophan fluorescence quenching assay, together with molecular docking, shows that PON1 activity is enhanced in correlation with the level of PC affinity to PON1. Molecular docking revealed that PCs interact specifically with H2-PON1 α-helix, which together with H1 enzyme α-helix links the protein to the HDL surface. These findings are supported by additional results from the PON1 ∆20 mutant that lack its H1-α-helix. Incubation of this mutant with the plaque C:M extract increased PON1 activity by only 20%, much less than the wild-type PON1 that elevated PON1 activity at the same concentration by as much as 95%. Furthermore, as much as the affinity of the enzyme to the PC was augmented, the ability of PON1 to bind to the HDL particle decreased. Finally, PON1 interaction with PC enhance its uptake into the macrophage cytoplasm. In conclusions, Specific lesion phosphatidylcholines (PCs) present in the human carotid plaque significantly enhance PON1 catalytic activities due to their interaction with the enzyme. Such a lesion׳s PC-PON1 interaction, in turn, competes with HDL PCs and enhances PON1 uptake by macrophage at the expense of PON1 binding to the HDL. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. WE-EF-BRA-09: Microbeam Radiation Therapy Enhances Tumor Drug Uptake of PEGylated Liposomal Doxorubicin (PLD) in a Triple Negative Breast Cancer GEM Model

    Energy Technology Data Exchange (ETDEWEB)

    Chang, SX; Madden, AJ; Rivera, JN; Santos, CM; Hunter, LM; Darr, DB; Zamboni, WC [UNC School of Medicine, Chapel Hill, NC (United States)

    2015-06-15

    Purpose: Overcoming low anti-cancer drug uptake in tumors is a key challenge limiting its clinical use. We propose to enhance the drug delivery using upfront Microbeam Radiation Therapy (MRT). MRT is a preclinical cancer therapy that utilizes microplanar beams to deliver spatially oscillating planes of high and low doses. Animal studies have demonstrated that ultrahigh dose (100s Gy) MRT eradicates tumors without damaging the function of normal tissue exposed to the same radiation. Our previous study indicated that MRT induces intense angiogenesis in tumor rim and surrounding normal tissue 1–2 days post radiation. We hypothesize that the tumor microenvironment modulation induced by MRT may enhance carrier-mediated agent drug delivery to tumors with inherent poor drug uptake. We thus investigated MRT-induced pharmacokinetics (PK) of PEGylated liposomal doxorubicin (PLD), a nano-scale doxorubicin, in T11 genetically engineered mouse model of triple negative breast cancer. Methods: A research irradiator (160kVp, RadSource Technologies) with a customized collimator was used to produce the MRT microbeam of in average 390µm width and 1190µm peak-to-peak distance. The peak dose rate of 1–2Gy/min. Dosimetry is by EBT3 film cross-calibrated with ion chamber at large fields. All mice were administered PLD at 6mg/kg IV x1 at 16h post MRT and sacrificed at 5min, 6h, 24h, and 96h post PLD administration (n=3 or 4 per group). Results: The MRT(28Gy)+PLD group mice had a total doxorubicin tumor concentration (area-under-the concentration-curve, AUC) of 206,040ng/mL•h, 3.71 times the concentration of the PLD-alone group. The MRT(34Gy)+PLD group had a higher mean total doxorubicin concentration in tumor (20,779ng/ml) than the MRT(28Gy)+PLD group (10,665ng/ml). Conclusion: Our preliminary results indicate that microbeam radiation therapy (MRT) can enhance nano-scale anti-cancer drug delivery to tumors approximately 4-fold. The exact working mechanism, the comparison with

  18. Comparison of thymidine phosphorylase expression and prognostic factors in gallbladder and bile duct cancer

    Directory of Open Access Journals (Sweden)

    You Young

    2010-10-01

    Full Text Available Abstract Background Biliary tract cancers have limitations in information about different location-related pathogenesis and clinico-pathological characteristics. The goal of this study was to investigate anatomical site-related similarities and differences in biliary tract cancers and to assess the expression and clinical significance of functional proteins such as p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1. Methods One hundred and sixty-one patients with biliary tract adenocarcinomas, who underwent curative or palliative surgery in a single institution between October 1994 and December 2003 were evaluated, retrospectively. The level of protein expression of p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1 was assessed by immunohistochemistry. Results With respect to clinico-pathological characteristics, gallbladder cancer was more frequent in women, and bile duct cancer was more common in men. Perineural invasion was more common in bile duct cancer. Recurrence as a distant metastasis was more common in gallbladder cancer. Immunohistochemical analysis revealed that thymidine phosphorylase expression was significantly higher in gallbladder cancer than in bile duct cancer. Positive thymidine phosphorylase and p53 staining were associated with an advanced stage. Differentiation, vascular invasion, perineural invasion, lymphatic invasion, lymph node metastasis, and TNM stage independently predicted poor prognosis in biliary tract cancer. These correlations were seen more clearly in gallbladder cancer. The immunohistochemical staining patterns of p53, cyclin D1, survivin, thymidine phosphorylase, and ERCC1 showed no prognostic significance in biliary tract cancers. Conclusions We concluded that gallbladder and bile duct cancers are considered to be separate diseases with different clinico-pathological characteristics and prognostic factors. In addition, we hypothesize that high expression of thymidine phosphorylase by

  19. Improved cellular uptake, enhanced efficacy and promising pharmacokinetic profile of docetaxel employing glycine-tethered C60-fullerenes.

    Science.gov (United States)

    Misra, Charu; Thotakura, Nagarani; Kumar, Rajendra; Singh, Bhupinder; Sharma, Gajanand; Katare, O P; Raza, Kaisar

    2017-07-01

    Water dispersible fullerenes were synthesized by tethering with glycine. The glycinated fullerenes were conjugated to docetaxel and characterized using FT-IR and NMR. The nanometric drug-loaded carriers were able to release drug at cancer cell pH, but resisted drug release at plasma pH. The cytotoxicity in MDA MB-231 cells was substantially enhanced as well as the system was well tolerated by erythrocytes. The confocal laser scanning microphotographs confirmed the substantial drug delivery to cytosol as well as nuclei of cancer cells. The developed system not only increased the circulation time of drug, but also decreased its protein binding and substantially enhanced AUC. The glycinated fullerenes can serve as promising "cargo vehicles" for delivery of anti-cancer drugs in safe and effective manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Hematite Reduction Buffers Acid Generation and Enhances Nutrient Uptake by a Fermentative Iron Reducing Bacterium, Orenia metallireducens Strain Z6.

    Science.gov (United States)

    Dong, Yiran; Sanford, Robert A; Chang, Yun-Juan; McInerney, Michael J; Fouke, Bruce W

    2017-01-03

    Fermentative iron-reducing organisms have been identified in a variety of environments. Instead of coupling iron reduction to respiration, they have been consistently observed to use ferric iron minerals as an electron sink for fermentation. In the present study, a fermentative iron reducer, Orenia metallireducens strain Z6, was shown to use iron reduction to enhance fermentation not only by consuming electron equivalents, but also by generating alkalinity that effectively buffers the pH. Fermentation of glucose by this organism in the presence of a ferric oxide mineral, hematite (Fe2O3), resulted in enhanced glucose decomposition compared with fermentation in the absence of an iron source. Parallel evidence (i.e., genomic reconstruction, metabolomics, thermodynamic analyses, and calculation of electron transfer) suggested hematite reduction as a proton-consuming reaction effectively consumed acid produced by fermentation. The buffering effect of hematite was further supported by a greater extent of glucose utilization by strain Z6 in media with increasing buffer capacity. Such maintenance of a stable pH through hematite reduction for enhanced glucose fermentation complements the thermodynamic interpretation of interactions between microbial iron reduction and other biogeochemical processes. This newly discovered feature of iron reducer metabolism also has significant implications for groundwater management and contaminant remediation by providing microbially mediated buffering systems for the associated microbial and/or chemical reactions.

  1. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber

    OpenAIRE

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    Although the effects of silicon application on enhancing plant salt tolerance have been widely investigated, the underlying mechanism has remained unclear. In this study, seedlings of cucumber, a medium silicon accumulator plant, grown in 0.83 mM silicon solution for 2 weeks were exposed to 65 mM NaCl solution for another 1 week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net...

  2. Application of theory to enhance audit and feedback interventions to increase the uptake of evidence-based transfusion practice: an intervention development protocol.

    Science.gov (United States)

    Gould, Natalie J; Lorencatto, Fabiana; Stanworth, Simon J; Michie, Susan; Prior, Maria E; Glidewell, Liz; Grimshaw, Jeremy M; Francis, Jill J

    2014-07-29

    Audits of blood transfusion demonstrate around 20% transfusions are outside national recommendations and guidelines. Audit and feedback is a widely used quality improvement intervention but effects on clinical practice are variable, suggesting potential for enhancement. Behavioural theory, theoretical frameworks of behaviour change and behaviour change techniques provide systematic processes to enhance intervention. This study is part of a larger programme of work to promote the uptake of evidence-based transfusion practice. The objectives of this study are to design two theoretically enhanced audit and feedback interventions; one focused on content and one on delivery, and investigate the feasibility and acceptability. Study A (Content): A coding framework based on current evidence regarding audit and feedback, and behaviour change theory and frameworks will be developed and applied as part of a structured content analysis to specify the key components of existing feedback documents. Prototype feedback documents with enhanced content and also a protocol, describing principles for enhancing feedback content, will be developed. Study B (Delivery): Individual semi-structured interviews with healthcare professionals and observations of team meetings in four hospitals will be used to specify, and identify views about, current audit and feedback practice. Interviews will be based on a topic guide developed using the Theoretical Domains Framework and the Consolidated Framework for Implementation Research. Analysis of transcripts based on these frameworks will form the evidence base for developing a protocol describing an enhanced intervention that focuses on feedback delivery. Study C (Feasibility and Acceptability): Enhanced interventions will be piloted in four hospitals. Semi-structured interviews, questionnaires and observations will be used to assess feasibility and acceptability. This intervention development work reflects the UK Medical Research Council's guidance

  3. Targeted Enhancement of H2 and CO2 Uptake for Autotrophic Production of Biodiesel in the Lithoautotrophic Bacterium Ralsonia Eutropha

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, C. A.; Sullivan, R.; Johnson, C.; Yu, J.; Maness, P. C.

    2013-01-01

    CO2 and H2 are promising feedstocks for production of valuable biocompounds. Ralstonia eutropha utilizes these feedstocks to generate energy (ATP) and reductant (NAD(P)H) via oxidation of H2 by a membrane-bound (MBH) and a soluble hydrogenase (SH) for CO2 fixation by the Calvin-Benson-Bassham (CBB) cycle. Increased expression of the enzyme that fixes CO2 (RubisCO) resulted in 6-fold activity improvement in vitro, while increased expression of the MBH operon or the SH operon plus MBH operon maturation factors necessary for activity resulted in a 10-fold enhancement. Current research involves genetic manipulation of two endogenous cbb operons for increased expression, analysis of expression and activity of CBB/MBH/SH, cofactor ratios, and downstream products during autotrophic growth in control versus enhanced strains, and development of strategies for long-term, optimal overexpression. These studies will improve our understanding of autotrophic metabolism and provide a chassis strain for autotrophic production of biodiesel and other valuable carbon biocompounds.

  4. Phosphate enhances uptake of As species in garland chrysanthemum (C. coronarium) applied with chicken manure bearing roxarsone and its metabolites.

    Science.gov (United States)

    Yao, Lixian; Huang, Lianxi; He, Zhaohuan; Zhou, Changming; Li, Guoliang; Deng, Xiancai

    2015-03-01

    Roxarsone (ROX), a world widely used feed organoarsenic additive in animal production, can be excreted as itself and its metabolites in animal manure. Animal manure is commonly land applied with phosphorous (P) fertilizer to enhance the P phytoavailability in agriculture. We investigated the accumulation of As species in garland chrysanthemum (C. coronarium) plants fertilized with 1% (w/w, manure/soil) chicken manure bearing ROX and its metabolites, plus 0, 0.05, 0.1, 0.2, 0.4, and 0.8 g P2O5/kg, respectively. The results show that As(III) was the sole As compound in garland chrysanthemum shoots, and As(III) and As(V) were detectable in roots. Elevated phosphate level supplied more As(V) for garland chrysanthemum roots through competitive desorption in rhizosphere, leading to significantly enhanced accumulation of As species in plants. As(III) was the predominant As form in plants (85.0∼90.6%). Phosphate could not change the allocation of As species in plants. Hence, the traditional practice that animal manure is applied with P fertilizer may inadvertently increase the potential risk of As contamination in crop via the way ROX → animal → animal manure → soil → crop.

  5. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber

    Science.gov (United States)

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    Although the effects of silicon application on enhancing plant salt tolerance have been widely investigated, the underlying mechanism has remained unclear. In this study, seedlings of cucumber, a medium silicon accumulator plant, grown in 0.83 mM silicon solution for 2 weeks were exposed to 65 mM NaCl solution for another 1 week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net photosynthetic rate, transpiration rate and leaf water content were higher in plants treated with silicon than in untreated plants under salt stress conditions. Further investigation showed that salt stress decreased root hydraulic conductance (Lp), but that silicon application moderated this salt-induced decrease in Lp. The higher Lp in silicon-treated plants may account for the superior plant water balance. Moreover, silicon application significantly decreased Na+ concentration in the leaves while increasing K+ concentration. Simultaneously, both free and conjugated types of polyamines were maintained at high levels in silicon-treated plants, suggesting that polyamines may be involved in the ion toxicity. Our results indicate that silicon enhances the salt tolerance of cucumber through improving plant water balance by increasing the Lp and reducing Na+ content by increasing polyamine accumulation. PMID:26442072

  6. 5TR1 aptamer-PEGylated liposomal doxorubicin enhances cellular uptake and suppresses tumour growth by targeting MUC1 on the surface of cancer cells.

    Science.gov (United States)

    Moosavian, Seyedeh Alia; Abnous, Khalil; Akhtari, Javad; Arabi, Leila; Gholamzade Dewin, Ali; Jafari, Mahmoudreza

    2017-12-05

    Employing targeting ligands with high affinity to tumour receptors is an important strategy to increase treatment efficacy. The use of aptamers as targeting agent is increasingly prevalent in drug delivery systems. Mucin1 (MUC1) is a glycoprotein that is over-expressed on the surface of several cancer cells and plays an important role in metastasis and invasion. 5TR1-aptamer is a DNA aptamer, which targets MUC1 receptors. The present study investigated the anti-tumour activity and therapeutic effectiveness of 5TR1-aptamer-PEGylated liposomal doxorubicin (PLD) delivery system in C26 tumour-bearing mice. The in vitro experiments demonstrated enhanced cytotoxicity and cellular uptake of PLD at the presence of 5TR1 aptamer into MUC1 + C26 cell line. Biodistribution study indicated that aptamer conjugation increased tumour accumulation of PLDs. Pharmacokinetic analysis showed despite higher clearance rate, selective delivery of doxorubicin to tumour tissue was increased in the 5TR1-Doxil group. In C26-bearing tumour mice, treatment with 5TR1-Doxil exhibited significant deceleration in tumour growth and enhanced survival. The results suggested that 5TR1 aptamer is promising ligand for active targeting which improves therapeutic efficiency of PLD in cancer therapy.

  7. Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

    Directory of Open Access Journals (Sweden)

    Norazlina Mohamad Yatim

    2016-01-01

    Full Text Available Efficient use of urea fertilizer (UF as important nitrogen (N source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs for enhancing the nitrogen uptake (NU and use efficiency (NUE. The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt% and functionalization reflux time (12–24 hrs with the corresponding responses (NUE, NU were structured via the Response Surface Methodology (RSM based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (p value < 0.05 for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

  8. Contribution of carboxyl modified chiral mesoporous silica nanoparticles in delivering doxorubicin hydrochloride in vitro: pH-response controlled release, enhanced drug cellular uptake and cytotoxicity.

    Science.gov (United States)

    Li, Jing; Du, Xiaotong; Zheng, Nan; Xu, Lu; Xu, Jinghua; Li, Sanming

    2016-05-01

    In this study, dual functionalized mesoporous silica nanoparticle (Dual-MSN) with functions of carboxyl modification and chirality was successfully developed and its special contribution in delivering doxorubicin hydrochloride (DOX) in vitro was mainly studied. Characteristics of Dual-MSN and its application as DOX carrier were intensively explored by comparing with naked non-functionalized MSN (Naked MSN). The results indicated that both Naked MSN and Dual-MSN significantly controlled DOX release due to the release hindrance caused by mesopores. As expected, Dual-MSN exhibited obvious enhanced pH-response because of its negative charges of carboxyl groups. DOX loaded Naked MSN and DOX loaded Dual-MSN presented better cytotoxicity than DOX due to carrier-mediated endocytosis and the favorable intercalation of DOX into DNA in the nuclei. The cytotoxicity of DOX loaded Dual-MSN was better than DOX loaded Naked MSN owing to its enhanced cellular uptake induced by chirality of Dual-MSN, demonstrating that double functions of Dual-MSN had unique advantages in improving antitumor effect of DOX towards MCF-7 cells and thus confirming its special contribution in DOX delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Tunable rare-earth fcu-MOFs: A platform for systematic enhancement of CO2 adsorption energetics and uptake

    KAUST Repository

    Xue, Dongxu

    2013-05-22

    A series of fcu-MOFs based on rare-earth (RE) metals and linear fluorinated/nonfluorinated, homo/heterofunctional ligands were targeted and synthesized. This particular fcu-MOF platform was selected because of its unique structural characteristics combined with the ability/potential to dictate and regulate its chemical properties (e.g., tuning of the electron-rich RE metal ions and high localized charge density, a property arising from the proximal positioning of polarizing tetrazolate moieties and fluoro-groups that decorate the exposed inner surfaces of the confined conical cavities). These features permitted a systematic gas sorption study to evaluate/elucidate the effects of distinctive parameters on CO2-MOF sorption energetics. Our study supports the importance of the synergistic effect of exposed open metal sites and proximal highly localized charge density toward materials with enhanced CO2 sorption energetics. © 2013 American Chemical Society.

  10. Partial neuromuscular blockade in humans enhances muscle blood flow during exercise independently of muscle oxygen uptake and acetylcholine receptor blockade

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Krustrup, Peter; Iaia, F Marcello

    2009-01-01

    This study examined the role of acetylcholine for skeletal muscle blood flow during exercise by use of the competitive neuromuscular blocking agent cisatracurium in combination with the acetylcholine receptor blocker glycopyrrone. Nine healthy male subjects performed a 10-min bout of one-legged k......This study examined the role of acetylcholine for skeletal muscle blood flow during exercise by use of the competitive neuromuscular blocking agent cisatracurium in combination with the acetylcholine receptor blocker glycopyrrone. Nine healthy male subjects performed a 10-min bout of one....... The enhanced exercise hyperemia during partial neuromuscular blockade may be related to a greater recruitment of fast-twitch muscle fibres. Key words: blood flow, neuromuscular blockade, exercise, skeletal muscle....

  11. Characterization of Oligomeric and Kinetic Properties of Tomato Thymidine Kinase 1

    DEFF Research Database (Denmark)

    Mutahir, Zeeshan; Larsen, Nicolai Balle; Andersson, Karl-Magnus

    2011-01-01

    The gene encoding thymidine kinase 1 from tomato (toTK1) has in combination with azidothymidine (AZT) recently been proposed as a powerful suicide gene for anticancer gene therapy. The toTK1/AZT combination has been demonstrated to have several advantages for the treatment of glioblastomas because...

  12. Bacterial incorporation of tritiated thymidine and populations of bacteriophagous fauna in the rhizosphere of wheat

    DEFF Research Database (Denmark)

    Christensen, Henrik; Griffiths, Bryan; Christensen, Søren

    1992-01-01

    Bacterial and microfaunal populations, and bacterial productivity measured by tritiated thymidine (3HTdr) incorporation, in the rhizosphere of wheat seedlings were measured. Soil from planted pots was fractionated into rhizosphere and non-rhizosphere (bulk) soil, while unplanted soil was taken fr...

  13. Elimination of the truncated message from the herpes simplex virus thymidine kinase suicide gene

    NARCIS (Netherlands)

    Chalmers, D; Ferrand, C; Apperley, JF; Melo, JV; Ebeling, S; Newton, [No Value; Duperrier, A; Hagenbeek, A; Garrett, E; Tiberghien, P; Garin, M

    Introduction of the Herpes simplex virus thymidine kinase (HSV-tk) gene into target cells renders them susceptible to killing by ganciclovir (GCV). We are studying the use of HSV-tk-transduced T lymphocytes in the context of hematopoietic stem cell transplantation. We have previously shown, in vitro

  14. Human cytosolic thymidine kinase: purification and physical characterization of the enzyme from HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Sherley, J.L.; Kelly, T.J.

    1988-01-05

    The mammalian cytosolic thymidine kinase is one of a number of enzymes involved in DNA replication whose activities increase dramatically during S phase of the cell cycle. As a first step in defining the mechanisms that control the S phase induction of thymidine kinase activity, the authors have purified the human enzyme from HeLa cells and raised a specific immune serum against the purified protein. The enzyme was isolated from cells arrested in S phase by treatment with methotrexate and purified to near homogeneity by ion-exchange and affinity chromatography. Stabilization of the purified enzyme was achieved by the addition of digitonin. An electrophoretic R/sub m/ of 0.2 in nondenaturing gels characterizes the purified enzyme activity as cytosolic thymidine kinase. The enzyme has a Stoke's radius of 40 A determined by gel filtration and a sedimentation coefficient of 5.5 S determined by glycerol gradient sedimentation. Based on these hydrodynamic values, a native molecular weight of 96,000 was calculated for the purified enzyme. When electrophoresed in denaturing sodium dodecyl sulfate-polyacrylamide gels under reducing conditions, the most purified enzyme fraction was found to contain one predominant polypeptide of M/sub r/ = 24,000. Several lines of evidence indicate that this polypeptide is responsible for thymidine kinase enzymatic activity.

  15. Radio diagnosis using 125I-fibrinogen and 203Hg-thymidine.

    Science.gov (United States)

    Zimmermann, M; Schmutz, H

    1976-12-30

    A comparative study of 125I-fibrinogen and 203Hg-thymidine using 144 Ehrlich carcinoma-bearing mice, indicates that tumor affinity of carrier substances with covalent labeling could be better used for scintigraphic tumor diagnosis. Halogenated or possibly metallo-organic compounds offer an alternative to the metal complexes in general use up to now.

  16. Treatment of malignant gliomas with a replicating adenoviral vector expressing herpes simplex virus-thymidine kinase

    NARCIS (Netherlands)

    D. Nanda (Dharminderkoemar); R. Vogels; M. Havenga; C.J.J. Avezaat (Cees); A. Bout; P.S. Smitt

    2001-01-01

    textabstractWe evaluated the interaction between oncolytic, replication-competent adenoviral vectors and the herpes simplex virus-1 thymidine kinase (HSV1-tk) gene/ganciclovir (GCV) suicide system for the treatment of malignant gliomas. We constructed a panel of

  17. Microwave-assisted synthesis and biological evaluation of novel uracil derivatives inhibiting human thymidine phosphorylase.

    Science.gov (United States)

    Corelli, Federico; Botta, Maurizio; Lossani, Andrea; Pasquini, Serena; Spadari, Silvio; Focher, Federico

    2004-12-01

    New 5-chloro-6-substituted-uracil derivatives have been prepared by microwave assisted-synthesis and tested in vitro as thymidine phosphorylase inhibitors. One of these compounds showed potent inhibitory activity, with an IC50 value in the submicromolar range. The biological activity of the new compounds is discussed in terms of structure-activity relationship.

  18. Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression with Radiolabeled 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in Liver by Hydrodynamic-based Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Song, In Ho; Lee, Tae Sup; Kang, Joo Hyun; Lee, Yong Jin; Kim, Kwang Il; An, Gwang Il; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-10-15

    Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynamic injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

  19. Is there an optimal training intensity for enhancing the maximal oxygen uptake of distance runners?: empirical research findings, current opinions, physiological rationale and practical recommendations.

    Science.gov (United States)

    Midgley, Adrian W; McNaughton, Lars R; Wilkinson, Michael

    2006-01-01

    The maximal oxygen uptake (V-dotO(2max)) is considered an important physiological determinant of middle- and long-distance running performance. Little information exists in the scientific literature relating to the most effective training intensity for the enhancement of V-dotO(2max) in well trained distance runners. Training intensities of 40-50% V-dotO(2max) can increase V-dotO(2max) substantially in untrained individuals. The minimum training intensity that elicits the enhancement of V-dotO(2max) is highly dependent on the initial V-dotO(2max), however, and well trained distance runners probably need to train at relative high percentages of V-dotO(2max) to elicit further increments. Some authors have suggested that training at 70-80% V-dotO(2max) is optimal. Many studies have investigated the maximum amount of time runners can maintain 95-100% V-dotO(2max) with the assertion that this intensity is optimal in enhancing V-dotO(2max). Presently, there have been no well controlled training studies to support this premise. Myocardial morphological changes that increase maximal stroke volume, increased capillarisation of skeletal muscle, increased myoglobin concentration, and increased oxidative capacity of type II skeletal muscle fibres are adaptations associated with the enhancement of V-dotO(2max). The strength of stimuli that elicit adaptation is exercise intensity dependent up to V-dotO(2max), indicating that training at or near V-dotO(2max) may be the most effective intensity to enhance V-dotO(2max) in well trained distance runners. Lower training intensities may induce similar adaptation because the physiological stress can be imposed for longer periods. This is probably only true for moderately trained runners, however, because all cardiorespiratory adaptations elicited by submaximal training have probably already been elicited in distance runners competing at a relatively high level.Well trained distance runners have been reported to reach a plateau in V

  20. MR-guided focused ultrasound: enhancement of intratumoral uptake of [{sup 3}H]-docetaxel in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Chen Lili; Mu Zhaomei; Hachem, Paul; Ma, C-M; Wallentine, Annie; Pollack, Alan, E-mail: lili.Chen@fccc.ed [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States)

    2010-12-21

    The purpose of this study is to quantify the enhancement of [{sup 3}H]-docetaxel in implanted prostate tumors treated with MR-guided pulsed focused ultrasound (MRgFUS). Human prostate cancer, LNCaP cells in 25 {mu}l, were implanted into the prostates of male nude mice. The tumor growth was directly monitored on MRI. When the tumor reached a designated size, MRgFUS treatment was performed using a focused ultrasound treatment system (InSightec ExAblate 2000) with a 1.5 T GE MR scanner. The tumor-bearing animals were randomly divided into three groups: group 1, MRgFUS treatment + [{sup 3}H]-docetaxel; group 2, [{sup 3}H]-docetaxel only and group 3, as a control. Animals in group 1 were treated with MRgFUS non-invasively. Immediately after the treatment, the animals received a single dose of tail vein injection of docetaxel at 15 mg kg{sup -1} mixed with [{sup 3}H]-docetaxel at 50 uCi kg{sup -1} in a total volume of 150 {mu}l. Animals in group 2 were treated the same as in group one, however without MRgFUS treatment. Animals in group 3 were treated as a control. Animals were sacrificed 30 min after i.v. injections regardless of whether or not they received focused ultrasound. Tumors were removed and processed. The radioactivity of [{sup 3}H]-docetaxel in the tumor tissue was quantitatively measured by a liquid scintillation counter. Our study showed that all animals tolerated the MRgFUS treatment well. Our data showed increased {sup 3}H-docetaxel concentration in the tumor in the MRgFUS-treated group (1079 {+-} 132 cmp/75 mg) versus those without MRgFUS treatment (524 {+-} 201 cmp/75 mg) with P = 0.037.

  1. Comparative pharmacodynamic studies with the novel serotonin uptake-enhancing tianeptine and -inhibiting fluvoxamine utilizing EEG mapping and psychometry.

    Science.gov (United States)

    Saletu, B; Grünberger, J; Anderer, P; Linzmayer, L; Zyhlarz, G

    1996-01-01

    In a double-blind, placebo-controlled study, the encephalotropic and psychotropic effects of tianeptine (TIA)--a new tricyclic antidepressant, enhancing serotonin reuptake--were investigated as compared with the serotonin reuptake inhibiting antidepressant, fluvoxamine (FLU), utilizing EEG mapping, psychometric and psychophysiological measures. 16 healthy volunteers (8 males, 8 females) aged 21-35 (man 27) years received randomized and at weekly intervals single oral doses of placebo, 12.5 and 25 mg TIA and 50 mg FLU. EEG recordings, psychometric and psychophysiological tests and evaluation of pulse, blood pressure and side effects were carried out at 0, 2, 4, 6 and 8 hours; blood sampling, in addition, at hour 1. TIA plasma levels rose fast to peaks at 1-2 hours and declined rapidly as well, while the MC5 metabolite peaked in the 4th hour and declined more slowly. EEG mapping demonstrated that both TIA and FLU induced significant changes in brain function between the 1st and 8th hour, which, however, differed in their time course. 12.5 mg TIA exhibited, as compared with placebo, slight activating properties in the EEG (decrease of delta and theta, increase of alpha and beta, acceleration of the centroid), parallelled by thymopsychic improvement (mood elevation). 25 mg TIA showed EEG activation up to the 4th hour, later EEG sedation, accompanied by an initial thymopsychic improvement and differential changes thereafter (improved mood, decreased vigility), with the noopsyche improving at all times (attention, Pauli test). 50 mg FLU induced initially sedation and thereafter activation, accompanied by thymopsychic deterioration and subsequent improvement, the latter also being observed in the noopsyche (attention, memory). In pupillary and skin conductance measures, generally a slight activation occurred after placebo, which was attenuated by 25 mg TIA. Correlation maps between plasma levels and EEG changes demonstrated: the higher the TIA plasma levels, the more

  2. Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

    Directory of Open Access Journals (Sweden)

    Keiko Yamaji

    Full Text Available Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

  3. Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

    Science.gov (United States)

    Yamaji, Keiko; Watanabe, Yumiko; Masuya, Hayato; Shigeto, Arisa; Yui, Hiroshi; Haruma, Toshikatsu

    2016-01-01

    Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s) underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

  4. Uptake of silver nanoparticles by DHA-treated cancer cells examined by surface-enhanced Raman spectroscopy in a microfluidic chip.

    Science.gov (United States)

    Zhai, Zhimin; Zhang, Fengqiu; Chen, Xiangyu; Zhong, Jie; Liu, Gang; Tian, Yangchao; Huang, Qing

    2017-03-29

    This paper reports on the synthesis and application of biocompatible and sensitive SERS nanoparticles for the study of uptake of nanoparticles into living cells in a microfluidic chip through surface-enhanced Raman spectroscopy (SERS). The nanoparticles were fabricated as beta-cyclodextrin-coated silver nanoparticles (Ag@CD NPs) modified with para-aminothiophenol (p-ATP) and folic acid (FA) on the surface. The p-ATP molecules act as the Raman reporter while the FA tags have high affinity for folate receptors (FR) that are over-expressed on the surface cancerous cells, so that the nanoparticles can enter the cells and be monitored by the Raman reporter. Therefore, the nanoparticles could be utilized not only as cell invaders due to endocytosis but also as a SERS sensitive probe to monitor the effect of FR-targeted drugs such as dihydroartemisinin (DHA) that induce the population change of FR on the membrane of living cells. As a result, we have successfully demonstrated that we are able to employ the Ag@CD@p-ATP@FA NPs to evaluate the number of NPs entering living cells quantitatively and correspondingly the drug effect on cancer cells in a well-controlled way.

  5. 18F-Fluorothymidine-Pet Imaging of Glioblastoma Multiforme: Effects of Radiation Therapy on Radiotracer Uptake and Molecular Biomarker Patterns

    Directory of Open Access Journals (Sweden)

    Sanjay Chandrasekaran

    2013-01-01

    Full Text Available Introduction. PET imaging is a useful clinical tool for studying tumor progression and treatment effects. Conventional 18F-FDG-PET imaging is of limited usefulness for imaging Glioblastoma Multiforme (GBM due to high levels of glucose uptake by normal brain and the resultant signal-to-noise intensity. 18F-Fluorothymidine (FLT in contrast has shown promise for imaging GBM, as thymidine is taken up preferentially by proliferating cells. These studies were undertaken to investigate the effectiveness of 18F-FLT-PET in a GBM mouse model, especially after radiation therapy (RT, and its correlation with useful biomarkers, including proliferation and DNA damage. Methods. Nude/athymic mice with human GBM orthografts were assessed by microPET imaging with 18F-FDG and 18F-FLT. Patterns of tumor PET imaging were then compared to immunohistochemistry and immunofluorescence for markers of proliferation (Ki-67, DNA damage and repair (γH2AX, hypoxia (HIF-1α, and angiogenesis (VEGF. Results. We confirmed that 18F-FLT-PET uptake is limited in healthy mice but enhanced in the intracranial tumors. Our data further demonstrate that 18F-FLT-PET imaging usefully reflects the inhibition of tumor by RT and correlates with changes in biomarker expression. Conclusions. 18F-FLT-PET imaging is a promising tumor imaging modality for GBM, including assessing RT effects and biologically relevant biomarkers.

  6. Molecular mechanisms of enhanced [18F] fluorodeoxy glucose (FDG) uptake in isochemically injured myocardium: the role of glucose transporter and hexokinase expression. Final technical report for period August 1, 1993--November 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Brosius, F.C. III

    1999-08-01

    We determined that there were no regional differences in GLUT1 or GLUT4 expression in normal dog heart. We demonstrated that glucose uptake was relatively enhanced in regions of severe ischemia in this model. We showed that GLUT1 mRNA and polypeptide expression but not GLUT4 expression were substantially and significantly increased in both ischemic and nonischemic myocardial regions after 6 hours. We also found that GLUT4 translocation and glucose uptake induced by ischemia in perfused rat hearts were not inhibited by Wortmannin, a PI3 kinase inhibitor, whereas insulin-stimulatd increases in GLUT4 translocation and glucose uptake were inhibited. To determine whether some of the same phenomena occurred in humans with chronic myocardial ischemia, we investigated myocardial GLUT mRNA expression in 11 patients who underwent coronary artery bypass surgery. We have cultured neonatal rat cardiomyocytes and tested the effects of several factors including hypoxia and insulin.

  7. Comparative active-site mutation study of human and Caenorhabditis elegans thymidine kinase 1

    DEFF Research Database (Denmark)

    Skovgaard, Tine; Uhlin, Ulla; Munch-Petersen, Birgitte

    2012-01-01

    The first step for the intracellular retention of several anticancer or antiviral nucleoside analogues is the addition of a phosphate group catalysed by a deoxyribonucleoside kinase such as thymidine kinase 1 (TK1). Recently, human TK1 (HuTK1) has been crystallized and characterized using different...... ligands. To improve our understanding of TK1 substrate specificity, we performed a detailed, mutation-based comparative structure-function study of the active sites of two thymidine kinases: HuTK1 and Caenorhabditis elegans TK1 (CeTK1). Specifically, mutations were introduced into the hydrophobic pocket...... surrounding the substrate base. In CeTK1, some of these mutations led to increased activity with deoxycytidine and deoxyguanosine, two unusual substrates for TK1-like kinases. In HuTK1, mutation of T163 to S resulted in a kinase with a 140-fold lower K(m) for the antiviral nucleoside analogue 3'-azido-3...

  8. Deoxyribonucleoside kinases in two aquatic bacteria with high specificity for thymidine and deoxyadenosine

    DEFF Research Database (Denmark)

    Tinta, Tinkara; Christiansen, Louise Slot; Konrad, Anke

    2012-01-01

    Deoxyribonucleoside kinases (dNKs) are essential in the mammalian cell but their 'importance' in bacteria, especially aquatic ones, is less clear. We studied two aquatic bacteria, Gram-negative Flavobacterium psychrophilum JIP02/86 and Polaribacter sp. MED152, for their ability to salvage...... deoxyribonucleosides (dNs). Both had a Gram-positive-type thymidine kinase (TK1), which could phosphorylate thymidine, and one non-TK1 dNK, which could efficiently phosphorylate deoxyadenosine and slightly also deoxycytosine. Surprisingly, the four tested dNKs could not phosphorylate deoxyguanosine, and apparently......, these two bacteria are missing this activity. When tens of available aquatic bacteria genomes were examined for the presence of dNKs, a majority had at least a TK1-like gene, but several lacked any dNKs. Apparently, among aquatic bacteria, the role of the dN salvage varies....

  9. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  10. Thyroid Scan and Uptake

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  11. Mutation Spectra of Herpes Simplex Virus Type 1 Thymidine Kinase Mutants

    OpenAIRE

    Lu, Qiaosheng; Hwang, Ying T.; Hwang, Charles B. C.

    2002-01-01

    To examine whether the exonuclease activity intrinsic to the polymerase (Pol) of herpes simplex virus type 1 can influence the mutational spectra, we applied the denaturing gradient gel electrophoresis (DGGE) system combined with sequencing to characterize thymidine kinase mutants isolated from both the wild-type virus and a mutant deficient in exonuclease activity, Y7. Wild-type viruses produced predominately frameshift mutations (67%), whereas Y7 replicated a significantly lower proportion ...

  12. A functional chimaeric S-layer-enhanced green fluorescent protein to follow the uptake of S-layer-coated liposomes into eukaryotic cells.

    Science.gov (United States)

    Ilk, Nicola; Küpcü, Seta; Moncayo, Gerald; Klimt, Sigrid; Ecker, Rupert C; Hofer-Warbinek, Renate; Egelseer, Eva M; Sleytr, Uwe B; Sára, Margit

    2004-04-15

    The chimaeric gene encoding a C-terminally truncated form of the S-layer protein SbpA of Bacillus sphaericus CCM 2177 and the EGFP (enhanced green fluorescent protein) was ligated into plasmid pET28a and cloned and expressed in Escherichia coli. Just 1 h after induction of expression an intense EGFP fluorescence was detected in the cytoplasm of the host cells. Expression at 28 degrees C instead of 37 degrees C resulted in clearly increased fluorescence intensity, indicating that the folding process of the EGFP moiety was temperature sensitive. To maintain the EGFP fluorescence, isolation of the fusion protein from the host cells had to be performed in the presence of reducing agents. SDS/PAGE analysis, immunoblotting and N-terminal sequencing of the isolated and purified fusion protein confirmed the presence of both the S-layer protein and the EGFP moiety. The fusion protein had maintained the ability to self-assemble in suspension and to recrystallize on peptidoglycan-containing sacculi or on positively charged liposomes, as well as to fluoresce. Comparison of fluorescence excitation and emission spectra of recombinant EGFP and rSbpA(31-1068)/EGFP revealed identical maxima at 488 and 507 nm respectively. The uptake of liposomes coated with a fluorescent monomolecular protein lattice of rSbpA(31-1068)/EGFP into HeLa cells was studied by confocal laser-scanning microscopy. The major part of the liposomes was internalized within 2 h of incubation and entered the HeLa cells by endocytosis.

  13. Bystander killing of malignant cells via the delivery of engineered thymidine-active deoxycytidine kinase for suicide gene therapy of cancer.

    Science.gov (United States)

    Neschadim, A; Wang, J C M; Lavie, A; Medin, J A

    2012-05-01

    Activity and specificity of chemotherapeutic agents against solid tumors can be augmented via the targeted or localized delivery of 'suicide' genes. Selective activation of specific prodrugs in cells expressing the 'suicide' gene drives their elimination by apoptosis, while also enabling the killing of adjacent bystander cells. Strong bystander effects can compensate for poor 'suicide' gene delivery, and depend on the prodrugs used and mechanisms for the acquisition of activated drug by the bystander population, such as the presence of gap junctional intercellular communications. Although a number of 'suicide' gene therapies for cancer have been developed and characterized, such as herpes simplex virus-derived thymidine kinase (HSV-tk)-based activation of ganciclovir, their limited success highlights the need for the development of more robust approaches. Limiting activation kinetics and evolution of chemoresistance are major obstacles. Here we describe 'suicide' gene therapy of cancer based on the lentivirus-mediated delivery of a thymidine-active human deoxycytidine kinase variant. This enzyme possesses substrate plasticity that enables it to activate a multitude of prodrugs, some with distinct mechanisms of action. We evaluated the magnitude and mechanisms of bystander effects induced by different prodrugs, and show that when used in combination, they can synergistically enhance the bystander effect while avoiding off-target toxicity.

  14. Cellular influx, efflux, and anabolism of 3-carboranyl thymidine analogs: potential boron delivery agents for neutron capture therapy.

    Science.gov (United States)

    Sjuvarsson, Elena; Damaraju, Vijaya L; Mowles, Delores; Sawyer, Michael B; Tiwari, Rohit; Agarwal, Hitesh K; Khalil, Ahmed; Hasabelnaby, Sherifa; Goudah, Ayman; Nakkula, Robin J; Barth, Rolf F; Cass, Carol E; Eriksson, Staffan; Tjarks, Werner

    2013-11-01

    3-[5-{2-(2,3-Dihydroxyprop-1-yl)-o-carboran-1-yl}pentan-1-yl]thymidine (N5-2OH) is a first generation 3-carboranyl thymidine analog (3CTA) that has been intensively studied as a boron-10 ((10)B) delivery agent for neutron capture therapy (NCT). N5-2OH is an excellent substrate of thymidine kinase 1 and its favorable biodistribution profile in rodents led to successful preclinical NCT of rats bearing intracerebral RG2 glioma. The present study explored cellular influx and efflux mechanisms of N5-2OH, as well as its intracellular anabolism beyond the monophosphate level. N5-2OH entered cultured human CCRF-CEM cells via passive diffusion, whereas the multidrug resistance-associated protein 4 appeared to be a major mediator of N5-2OH monophosphate efflux. N5-2OH was effectively monophosphorylated in cultured murine L929 [thymidine kinase 1 (TK1(+))] cells whereas formation of N5-2OH monophosphate was markedly lower in L929 (TK1(-)) cell variants. Further metabolism to the di- and triphosphate forms was not observed in any of the cell lines. Regardless of monophosphorylation, parental N5-2OH was the major intracellular component in both TK1(+) and TK1(-) cells. Phosphate transfer experiments with enzyme preparations showed that N5-2OH monophosphate, as well as the monophosphate of a second 3-carboranyl thymidine analog [3-[5-(o-carboran-1-yl)pentan-1-yl]thymidine (N5)], were not substrates of thymidine monophosphate kinase. Surprisingly, N5-diphosphate was phosphorylated by nucleoside diphosphate kinase although N5-triphosphate apparently was not a substrate of DNA polymerase. Our results provide valuable information on the cellular metabolism and pharmacokinetic profile of 3-carboranyl thymidine analogs.

  15. Early assessment of therapy response in malignant lymphoma with the thymidine analogue [{sup 18}F]FLT

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Andreas K. [University Hospital Ulm, Department of Nuclear Medicine, Ulm (Germany); Technical University Munich, Department of Nuclear Medicine, Munich (Germany); Kratochwil, Clemens; Glatting, Gerhard; Tepsic, Djurdja; Vogg, Andreas T.J.; Neumaier, Bernd; Reske, Sven N. [University Hospital Ulm, Department of Nuclear Medicine, Ulm (Germany); Juweid, Malik [University of Iowa, Department of Radiology and Holden Comprehensive Cancer Center, Iowa City, IA (United States); Bommer, Martin [University Hospital Ulm, Department of Haematology, Ulm (Germany); Mattfeldt, Torsten; Moeller, Peter [University Hospital Ulm, Institute of Pathology, Ulm (Germany)

    2007-11-15

    The aim of this study was to determine whether the thymidine analogue 3'-deoxy-3'-[{sup 18}F]fluorothymidine ([{sup 18}F]FLT) is adequate for early evaluation of the response of malignant lymphoma to antiproliferative treatment in a mouse xenotransplant model. Immunodeficient mice bearing a follicular lymphoma xenotransplant were treated with high-dose chemotherapy (cyclophosphamide, n = 10), immunotherapy (CD20 mAb, ibritumomab-tiuxetan, n = 10) or radioimmunotherapy ([{sup 90}Y]CD20 mAb, Zevalin, n = 10). Forty-eight hours after treatment, antiproliferative effects were assessed with [{sup 18}F]FLT. Ninety minutes after i.v. injection of 5-10 MBq [{sup 18}F]FLT, mice were sacrificed and radioactivity within the tumour and normal organs was measured using a gamma counter and calculated as % ID/g. The proliferation fraction in tissue samples derived from treated and untreated tumours was evaluated by Ki-67 immunohistochemistry, which served as the reference for proliferative activity. In untreated lymphoma, the mean proliferation fraction was 83.6%. After chemotherapy, the mean proliferation fraction decreased to 39.3% (p = 0.0001), after immunotherapy to 77.6% (p = 0.0078) and after radioimmunotherapy to 78.8% (p = 0.014). In none of the animals was a significant change in tumour size observed. In untreated lymphoma, tumoural [{sup 18}F]FLT uptake was 5.4% ID/g, after chemotherapy it was 1.5% (p = 0.0005), after immunotherapy, 3.9% (non-significant), and after radioimmunotherapy, 5.8% (non-significant). In a lymphoma xenotransplant model, [{sup 18}F]FLT detects early antiproliferative drug activity before changes in tumour size are visible. These findings further support the use of [{sup 18}F]FLT-PET for imaging early response to treatment in malignant lymphoma. (orig.)

  16. Procollagen C-endopeptidase Enhancer Protein 2 (PCPE2) Reduces Atherosclerosis in Mice by Enhancing Scavenger Receptor Class B1 (SR-BI)-mediated High-density Lipoprotein (HDL)-Cholesteryl Ester Uptake.

    Science.gov (United States)

    Pollard, Ricquita D; Blesso, Christopher N; Zabalawi, Manal; Fulp, Brian; Gerelus, Mark; Zhu, Xuewei; Lyons, Erica W; Nuradin, Nebil; Francone, Omar L; Li, Xiang-An; Sahoo, Daisy; Thomas, Michael J; Sorci-Thomas, Mary G

    2015-06-19

    Studies in human populations have shown a significant correlation between procollagen C-endopeptidase enhancer protein 2 (PCPE2) single nucleotide polymorphisms and plasma HDL cholesterol concentrations. PCPE2, a 52-kDa glycoprotein located in the extracellular matrix, enhances the cleavage of C-terminal procollagen by bone morphogenetic protein 1 (BMP1). Our studies here focused on investigating the basis for the elevated concentration of enlarged plasma HDL in PCPE2-deficient mice to determine whether they protected against diet-induced atherosclerosis. PCPE2-deficient mice were crossed with LDL receptor-deficient mice to obtain LDLr(-/-), PCPE2(-/-) mice, which had elevated HDL levels compared with LDLr(-/-) mice with similar LDL concentrations. We found that LDLr(-/-), PCPE2(-/-) mice had significantly more neutral lipid and CD68+ infiltration in the aortic root than LDLr(-/-) mice. Surprisingly, in light of their elevated HDL levels, the extent of aortic lipid deposition in LDLr(-/-), PCPE2(-/-) mice was similar to that reported for LDLr(-/-), apoA-I(-/-) mice, which lack any apoA-I/HDL. Furthermore, LDLr(-/-), PCPE2(-/-) mice had reduced HDL apoA-I fractional clearance and macrophage to fecal reverse cholesterol transport rates compared with LDLr(-/-) mice, despite a 2-fold increase in liver SR-BI expression. PCPE2 was shown to enhance SR-BI function by increasing the rate of HDL-associated cholesteryl ester uptake, possibly by optimizing SR-BI localization and/or conformation. We conclude that PCPE2 is atheroprotective and an important component of the reverse cholesterol transport HDL system. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Oncolytic adenoviruses armed with thymidine kinase can be traced by PET imaging and show potent antitumoural effects by ganciclovir dosing.

    Directory of Open Access Journals (Sweden)

    Daniel Abate-Daga

    Full Text Available Replication-competent adenoviruses armed with thymidine kinase (TK combine the concepts of virotherapy and suicide gene therapy. Moreover TK-activity can be detected by noninvasive positron emission-computed tomography (PET imaging, what could potentially facilitate virus monitoring in vivo. Here, we report the generation of a novel oncolytic adenovirus that incorporates the Tat8-TK gene under the control of the Major Late Promoter in a highly selective backbone thus providing selectivity by targeting the retinoblastoma pathway. The selective oncolytic TK virus, termed ICOVIR5-TK-L, showed reduced potency compared to a non-selective counterpart. However the combination of ICOVIR5-TK-L with ganciclovir (GCV induced a potent antitumoural effect similar to that of wild type adenovirus in a preclinical model of pancreatic cancer. Although the treatment with GCV provoked a reduction in the viral yield, both in vitro and in vivo, a two-cycle treatment of virus and GCV resulted in an enhanced antitumoral response that correlated with high TK-activity, based on microPET measurements. Thus, TK-expressing oncolytic adenoviruses can be traced by PET imaging providing real time information on the activity of the virus and its antitumoral potency can be optimized by GCV dosing.

  18. Differences in temporal aspects of mutagenesis and cytotoxicity in Chinese hamster cells treated with methylating agents and thymidine.

    Science.gov (United States)

    Peterson, A R; Peterson, H

    1982-01-01

    Equitoxic concentrations of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and methyl methanesulfonate (MeMes) produced different frequencies of 8-azaguanine-resistant mutants and different amounts of N7-methylguanine, O6-methylguanine (m6G), and N3-methyladenine in the DNA of V79 Chinese hamster cells. Thus, neither the cytotoxicities nor the mutagenicities of these methylating agents could be attributed solely to nitrogen or to oxygen methylations in the DNA. However, MNNG produced 12-fold more m6G and 5-fold more mutants than did MeMes, indicating that a substantial part of the MNNG-induced mutations resulted from m6G--thymine mispairing during DNA replication. The expression as mutants of mutagenic oxygen methylations in the DNA of cells treated with MNNG was enhanced by thymidine (dThd) and deoxycytidine (dCyd), but these nucleosides did not significantly enhance MeMes-induced mutagenesis. The cytotoxicities of MNNG and MeMes were also increased by 10 microM dThd in proportion to the amount of m6G in the DNA. These increases in cytotoxicity were abolished by dCyd, which did not greatly reduce the dThd-induced enhancements of mutagenesis. Moreover, when dThd was present only during the 2-hr treatment with MNNG, maximal cytotoxicity occurred, but MNNG-induced mutagenesis was not increased. Maximal mutagenesis occurred when the dThd was present throughout the first doubling time of the MNNG-treated cells. Thus, the expression of the cytotoxicity and the mutagenicity associated with m6G in the DNA of V79 cells occurred by quite different mechanisms. PMID:6951203

  19. [3H]-thymidine labelling of DNA triggers apoptosis potentiated by E1A-adenoviral protein.

    Science.gov (United States)

    Orlov, S N; Pchejetski, D V; Sarkissian, S D; Adarichev, V; Taurin, S; Pshezhetsky, A V; Tremblay, J; Maximov, G V; deBlois, D; Bennett, M R; Hamet, P

    2003-03-01

    [(3)H]-thymidine is commonly used to analyze the accumulation of [(3)H]-labeled chromatin fragments in cells undergoing apoptosis. This study shows that [(3)H]-thymidine incorporation within DNA is sufficient per se to inhibit growth and to induce apoptosis in canine kidney epithelial cells and porcine aorta endothelial cells. Despite high-level [(3)H]-thymidine-DNA labeling, rat vascular smooth muscle cells (VSMC) showed only modest inhibition of growth and induction of apoptosis compared to other cell types. Similarly to serum deprivation, apoptosis triggered by [(3)H]-thymidine labeling was sharply potentiated by VSMC transfection with a functional analogue of c-myc, E1A-adenoviral protein (VSMC-E1A), and was suppressed by stimulation of cAMP signaling with forskolin as well as by and Na/K pump inhibition with ouabain. Both apoptosis induction and growth suppression seen in [(3)H]-thymidine-treated VSMC-E1A were reduced by the pan-caspase inhibitor z-VAD.fmk. Thus, our results show that the differential efficiency of the apoptotic machinery determines cell type-specific attenuation of growth in cells with [(3)H]-thymidine-labeled DNA. They also demonstrate that [(3)H]-thymidine-treated and serum-deprived VSMC employ common intermediates of the apoptotic machinery, including steps that are potentiated by E1A-adenoviral protein and inhibited by activation of cAMP signaling as well as by inversion of the intracellular [Na(+)](i)/[K(+)](i) ratio.

  20. Is there any additional benefit of contrast-enhanced CT as part of routine PET/CT protocols for the differentiation of suspicious incidental gastrointestinal 2-deoxy-{sup 18}F-FDG uptake?

    Energy Technology Data Exchange (ETDEWEB)

    Brendle, Cornelia Bettina; Aschoff, Phillip; Kratt, Thomas; Schraml, Christina; Reimold, Matthias; Claussen, Claus Detlef; Pfannenberg, Christina Anna [University Hospital Tuebingen, Tuebingen (Germany)

    2013-12-15

    Suspicious incidental gastrointestinal FDG uptake during positron-emission tomography/computed tomography (PET/CT) examinations can be caused by different diseases, including malignancies. However, differentiation with PET alone is difficult. The aim of this study was to investigate the potential of PET alone, contrast-enhanced CT (ceCT), and low-dose CT (ldCT) in routine PET/CT protocols for differentiation of incidental gastrointestinal lesions. Sixty patients with incidental gastrointestinal lesions who underwent a routine PET/CT protocol with ldCT and ceCT were retrospectively analysed. The PET lesions were evaluated regarding their FDG uptake patterns and the standard uptake value. The anatomical correlates in both CT protocols were compared in regard to the correct lesion classification with the reference standard endoscopy. Sixty-two lesions were found in 60 patients (17 malignant, 10 premalignant, 5 benign, 13 inflammatory, 17 physiological). The differentiation of the FDG uptake patterns did not enable reliable lesion classification. The positive predictive value for pathology was 0.81 for ceCT in PET/CT and 0.70 for ldCT. Malignancies were detected in 100% of the patients by ceCT vs. 29.4% by ldCT. The false negative rate of ceCT for all pathologies was 31.1%, vs. 68.9% for ldCT. False positive results (17/62) could not be excluded sufficiently by either CT protocol. PET/ceCT protocols provide additional benefit especially in detecting gastrointestinal malignancies as a cause of suspicious incidental gastrointestinal FDG uptake. However, since follow-up endoscopy cannot be forgone due to the considerable false negative rate even with ceCT, the addition of ceCT to a routine PET/ldCT protocol cannot be recommended for this purpose.

  1. Thymine utilization in Escherichia coli K12. On the role of deoxyribose 1-phosphate and thymidine phosphorylase

    DEFF Research Database (Denmark)

    Jensen, Kaj Frank; Leer, Johan Christian; Nygaard, Per

    1973-01-01

    to be presented in this paper indicate that the ability of different thymine auxotrophs to grow on progressively lower thymine concentrations is a function of their capacity to increase the internal pool of deoxyribose 1-phosphate and/or the level of thymidine phosphorylase. Thymine incorporation in wild...... to the external thymine concentration. The experiments in vivo led us to conclude that the incorporation of exogenous thymine occurs via thymidine, which is synthesized from thymine and deoxyribose 1-phosphate, catalyzed by thymidine phosphorylase. In accordance with this studies in vitro with purified thymidine...

  2. The endozepine ODN stimulates [{sup 3}H]thymidine incorporation in cultured rat astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Gandolfo, P.; Patte, C.; Thoumas, J.L.; Leprince, J.; Vaudry, H.; Tonon, M.C. [European Institute for Peptide Research (IFRMP no. 23), Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U 413, UA CNRS, University of Rouen, 76821 Mont-Saint-Aignan (France)

    1999-05-15

    High concentrations of diazepam-binding inhibitor (DBI) mRNA have been detected in astrocytoma, suggesting that DBI-derived peptides may play a role in glial cell proliferation. In the present study, we have investigated the effect of a processing product of DBI, the octadecaneuropeptide ODN, on DNA synthesis in cultured rat astrocytes. At very low concentrations (10{sup -14} to 10{sup -11} M), ODN caused a dose-dependent increase of [{sup 3}H]thymidine incorporation. At higher doses (10{sup -10} to 10{sup -5} M), the effect of ODN gradually declined. The central-type benzodiazepine receptor antagonist flumazenil (10{sup -6} M) completely suppressed the stimulatory action of ODN whereas the peripheral-type benzodiazepine receptor ligand, PK11195 (10{sup -6} M) had no effect. The ODN-induced stimulation of [{sup 3}H]thymidine incorporation was mimicked by methyl 6,7-dimethoxy-4-ethyl-{beta}-carboline-3-carboxylate (DMCM). The GABA{sub A} receptor antagonist bicuculline (10{sup -4} M) suppressed the effect of both ODN and DMCM on DNA synthesis. Exposure of cultured astrocytes to the specific GABA{sub A} agonist 3APS (10{sup -10} to 10{sup -4} M) also induced a dose-related increase of [{sup 3}H]thymidine incorporation. The present study indicates that ODN, acting through central-type benzodiazepine receptors associated with the GABA{sub A} receptor complex, stimulates DNA synthesis in rat glial cells. These data provide evidence for an autocrine role of endozepines in the control of glial cell proliferation. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Autoradiographic investigation of sperm transit through the male mouse genital tract after tritiated thymidine incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Dadoune, J.P.; Alfonsi, M.F. (Faculte de Medecine Broussais-Hotel-Dieu, U.E.R. Biomedicale des Saints-Peres, 75 - Paris (France))

    1984-01-01

    The transit of spermatozoa in the genital tract of the male mouse was investigated by quantitative light microscopic autoradiography after intraperitoneal injection of tritiated thymidine. Transit duration in the caput and the corpus of the epididymis was shown to be 3 days; the total duration of transit in the genital tract was 5 days. These findings indicate that the time required for the transit of spermatozoa in the epididymal caput and corpus was comparable to that calculated in other mammals studied. However, the duration of sperm storage in the epididymal cauda appeared to be shorter than that previously reported for rodents.

  4. Characterization of the Denitrification-Associated Phosphorus Uptake Properties of “Candidatus Accumulibacter phosphatis” Clades in Sludge Subjected to Enhanced Biological Phosphorus Removal

    Science.gov (United States)

    Kim, Jeong Myeong; Lee, Hyo Jung; Lee, Dae Sung

    2013-01-01

    To characterize the denitrifying phosphorus (P) uptake properties of “Candidatus Accumulibacter phosphatis,” a sequencing batch reactor (SBR) was operated with acetate. The SBR operation was gradually acclimated from anaerobic-oxic (AO) to anaerobic-anoxic-oxic (A2O) conditions by stepwise increases of nitrate concentration and the anoxic time. The communities of “Ca. Accumulibacter” and associated bacteria at the initial (AO) and final (A2O) stages were compared using 16S rRNA and polyphosphate kinase genes and using fluorescence in situ hybridization (FISH). The acclimation process led to a clear shift in the relative abundances of recognized “Ca. Accumulibacter” subpopulations from clades IIA > IA > IIF to clades IIC > IA > IIF, as well as to increases in the abundance of other associated bacteria (Dechloromonas [from 1.2% to 19.2%] and “Candidatus Competibacter phosphatis” [from 16.4% to 20.0%]), while the overall “Ca. Accumulibacter” abundance decreased (from 55.1% to 29.2%). A series of batch experiments combined with FISH/microautoradiography (MAR) analyses was performed to characterize the denitrifying P uptake properties of the “Ca. Accumulibacter” clades. In FISH/MAR experiments using slightly diluted sludge (∼0.5 g/liter), all “Ca. Accumulibacter” clades successfully took up phosphorus in the presence of nitrate. However, the “Ca. Accumulibacter” clades showed no P uptake in the presence of nitrate when the sludge was highly diluted (∼0.005 g/liter); under these conditions, reduction of nitrate to nitrite did not occur, whereas P uptake by “Ca. Accumulibacter” clades occurred when nitrite was added. These results suggest that the “Ca. Accumulibacter” cells lack nitrate reduction capabilities and that P uptake by “Ca. Accumulibacter” is dependent upon nitrite generated by associated nitrate-reducing bacteria such as Dechloromonas and “Ca. Competibacter.” PMID:23335771

  5. New Variants of Tomato Thymidine Kinase 1 Selected for Increased Sensitivity of E. coli KY895 towards Azidothymidine

    DEFF Research Database (Denmark)

    Christiansen, Louise Slot; Egeblad, Louise; Munch-Petersen, Birgitte

    2015-01-01

    Nucleoside analogues (NA) are prodrugs that are phosphorylated by deoxyribonucleoside kinases (dNKs) as the first step towards a compound toxic to the cell. During the last 20 years, research around dNKs has gone into new organisms other than mammals and viruses. Newly discovered dNKs have been...... tested as enzymes for suicide gene therapy. The tomato thymidine kinase 1 (ToTK1) is a dNK that has been selected for its in vitro kinetic properties and then successfully been tested in vivo for the treatment of malignant glioma. We present the selection of two improved variants of ToTK1 generated...... for the NA AZT over the natural substrate thymidine as well as a decrease in inhibition by dTTP, the end product of the nucleoside salvage pathway for thymidine. The understanding of the enzymatic properties improving the variants efficacy is instrumental to further develop dNKs for use in suicide gene...

  6. Novel theranostic zinc phthalocyanine-phospholipid complex self-assembled nanoparticles for imaging-guided targeted photodynamic treatment with controllable ROS production and shape-assisted enhanced cellular uptake.

    Science.gov (United States)

    Ma, Jinyuan; Li, Yang; Liu, Guihua; Li, Ai; Chen, Yilin; Zhou, Xinyi; Chen, Dengyue; Hou, Zhenqing; Zhu, Xuan

    2018-02-01

    The novel drug delivery system based on self-assembly of zinc phthalocyanine-soybean phosphatidylcholine (ZnPc-SPC) complex was developed by a co-solvent method followed by a nanoprecipitaion technique. DSPE-PEG-methotrexate (DSPE-PEG-MTX) was introduced on the surface of ZnPc-SPC self-assembled nanoparticles (ZS) to endow them with folate receptor-targeting property. NMR, XRD, FTIR, and UV-vis-NIR analysis demonstrated the weak molecular interaction between ZnPc and SPC. The ZS functionalized with DSPE-PEG-MTX (ZSPM) was successfully constructed with an average particle size of ∼170nm, a narrow size distribution, and could remain physiologically stable for at least 7days. In vitro cellular uptake and cytotoxicity studies demonstrated that ZSPM exhibited stronger cellular uptake efficacy and photodynamic cytotoxicity against HeLa and MCF-7 cells than ZS functionalized with DSPE-mPEG (ZSP) and free ZnPc. More importantly, ZSPM showed the enhanced accumulation effect at the tumor region compared with ZSP by the active-plus-passive targeting via enhanced permeability and retention (EPR) effect and folate receptor-mediated endocytosis. Furthermore, in vivo antitumor effect and histological analysis demonstrated the superior tumor growth inhibition effect of ZSPM. In addition, the needle-shape ZSP (ZSPN) exhibited better in vitro cellular uptake and in vivo tumor accumulation compared with ZSP due to the shape-assisted effect. Moreover, the interesting off-on switch effect of reactive oxygen species (ROS) production of ZnPc-SPC complex-based nanoparticles was discovered to achieve photodynamic treatment in a controllable way. These findings suggested that the ZnPc-SPC complex-based self-assembled nanoparticles could serve as a promising and effective formulation to achieve tumor-targeting fluorescence imaging and enhanced photodynamic treatment. Copyright © 2017. Published by Elsevier B.V.

  7. Adaptation of a retrovirus as a eucaryotic vector transmitting the herpes simplex virus thymidine kinase gene.

    Science.gov (United States)

    Tabin, C J; Hoffmann, J W; Goff, S P; Weinberg, R A

    1982-01-01

    We investigated the feasibility of using retroviruses as vectors for transferring DNA sequences into animal cells. The thymidine kinase (tk) gene of herpes simplex virus was chosen as a convenient model. The internal BamHI fragments of a DNA clone of Moloney leukemia virus (MLV) were replaced with a purified BamHI DNA segment containing the tk gene. Chimeric genomes were created carrying the tk insert in both orientations relative to the MLV sequence. Each was transfected into TK- cells along with MLV helper virus, and TK+ colonies were obtained by selection in the presence of hypoxanthine, aminopterin, and thymidine (HAT). Virus collected from TK+-transformed, MLV producer cells passed the TK+ phenotype to TK- cells. Nonproducer cells were isolated, and TK+ transducing virus was subsequently rescued from them. The chimeric virus showed single-hit kinetics in infections. Virion and cellular RNA and cellular DNA from infected cells were all shown to contain sequences which hybridized to both MLV- and tk-specific probes. The sizes of these sequences were consistent with those predicted for the chimeric virus. In all respects studied, the chimeric MLV-tk virus behaved like known replication-defective retroviruses. These experiments suggest great general applicability of retroviruses as eucaryotic vectors. Images PMID:6180306

  8. Two thymidine kinases and one multisubstrate deoxyribonucleoside kinase salvage DNA precursors in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Clausen, Anders R.; Girandon, Lenart; Ali, Ashfaq

    2012-01-01

    Deoxyribonucleotides are the building blocks of DNA and can be synthesized via de novo and salvage pathways. Deoxyribonucleoside kinases (EC 2.7.1.145) salvage deoxyribonucleosides by transfer of a phosphate group to the 5′ of a deoxyribonucleoside. This salvage pathway is well characterized....... Deoxyribonucleoside kinase activities were present in all tissues during all growth stages. In the A. thaliana genome, we identified two types of genes that could encode enzymes which are involved in the salvage of deoxyribonucleosides. Thymidine kinase activity was encoded by two thymidine kinase 1 (EC 2.......7.1.21)‐like genes (AtTK1a and AtTK1b). Deoxyadenosine, deoxyguanosine and deoxycytidine kinase activities were encoded by a single AtdNK gene. T‐DNA insertion lines of AtTK1a and AtTK1b mutant genes had normal growth, although AtTK1a AtTK1b double mutants died at an early stage, which indicates that AtTK1a...

  9. Two thymidine kinases and one multisubstrate deoxyribonucleoside kinase salvage DNA precursors in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Anders Ranegaard Clausen, Anders Ranegaard; Girandon, Lenart; Ali, Ashfaq

    2012-01-01

    Deoxyribonucleotides are the building blocks of DNA and can be synthesized via de novo and salvage pathways. Deoxyribonucleoside kinases (EC 2.7.1.145) salvage deoxyribonucleosides by transfer of a phosphate group to the 5' of a deoxyribonucleoside. This salvage pathway is well characterized....... Deoxyribonucleoside kinase activities were present in all tissues during all growth stages. In the A. thaliana genome, we identified two types of genes that could encode enzymes which are involved in the salvage of deoxyribonucleosides. Thymidine kinase activity was encoded by two thymidine kinase 1 (EC 2.......7.1.21)-like genes (AtTK1a and AtTK1b). Deoxyadenosine, deoxyguanosine and deoxycytidine kinase activities were encoded by a single AtdNK gene. T-DNA insertion lines of AtTK1a and AtTK1b mutant genes had normal growth, although AtTK1a AtTK1b double mutants died at an early stage, which indicates that AtTK1a...

  10. Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

    Energy Technology Data Exchange (ETDEWEB)

    Villarroya, Joan, E-mail: joanvillarroya@gmail.com [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Institut de Recerca l' Hospital de la Santa Creu i Sant Pau, Barcelona (Spain); Lara, Mari-Carmen [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Department of Neurology, Columbia University Medical Center, New York, NY (United States); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Dorado, Beatriz [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Garrido, Marta [Unitat de Biologia Cel.lular i Molecular, IMIM-Hospital del Mar, Barcelona (Spain); Garcia-Arumi, Elena [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), ISCIII (Spain); Meseguer, Anna [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain); Hirano, Michio [Department of Neurology, Columbia University Medical Center, New York, NY (United States); Vila, Maya R. [Institut de Recerca, Hospital Universitari de la Vall d' Hebron, Barcelona (Spain)

    2011-04-08

    Highlights: {yields} We impaired TK2 expression in Ost TK1{sup -} cells via siRNA-mediated interference (TK2{sup -}). {yields} TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. {yields} Despite mtDNA depletion, TK2{sup -} cells show high cytochrome oxidase activity. {yields} Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. {yields} Nuclear-encoded ENT1, DNA-pol {gamma}, TFAM and TP gene expression is lowered in TK2{sup -} cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1{sup -} cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase {gamma}, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity

  11. Cinnamon extract enhances glucose uptake in 3T3-L1 adipocytes and C2C12 myocytes by inducing LKB1-AMP-activated protein kinase signaling.

    Directory of Open Access Journals (Sweden)

    Yan Shen

    Full Text Available We previously demonstrated that cinnamon extract (CE ameliorates type 1 diabetes induced by streptozotocin in rats through the up-regulation of glucose transporter 4 (GLUT4 translocation in both muscle and adipose tissues. This present study was aimed at clarifying the detailed mechanism(s with which CE increases the glucose uptake in vivo and in cell culture systems using 3T3-L1 adipocytes and C2C12 myotubes in vitro. Specific inhibitors of key enzymes in insulin signaling and AMP-activated protein kinase (AMPK signaling pathways, as well as small interference RNA, were used to examine the role of these kinases in the CE-induced glucose uptake. The results showed that CE stimulated the phosphorylation of AMPK and acetyl-CoA carboxylase. An AMPK inhibitor and LKB1 siRNA blocked the CE-induced glucose uptake. We also found for the first time that insulin suppressed AMPK activation in the adipocyte. To investigate the effect of CE on type 2 diabetes in vivo, we further performed oral glucose tolerance tests and insulin tolerance tests in type 2 diabetes model rats administered with CE. The CE improved glucose tolerance in oral glucose tolerance tests, but not insulin sensitivity in insulin tolerance test. In summary, these results indicate that CE ameliorates type 2 diabetes by inducing GLUT4 translocation via the AMPK signaling pathway. We also found insulin antagonistically regulates the activation of AMPK.

  12. Cinnamon extract enhances glucose uptake in 3T3-L1 adipocytes and C2C12 myocytes by inducing LKB1-AMP-activated protein kinase signaling.

    Science.gov (United States)

    Shen, Yan; Honma, Natsumi; Kobayashi, Katsuya; Jia, Liu Nan; Hosono, Takashi; Shindo, Kazutoshi; Ariga, Toyohiko; Seki, Taiichiro

    2014-01-01

    We previously demonstrated that cinnamon extract (CE) ameliorates type 1 diabetes induced by streptozotocin in rats through the up-regulation of glucose transporter 4 (GLUT4) translocation in both muscle and adipose tissues. This present study was aimed at clarifying the detailed mechanism(s) with which CE increases the glucose uptake in vivo and in cell culture systems using 3T3-L1 adipocytes and C2C12 myotubes in vitro. Specific inhibitors of key enzymes in insulin signaling and AMP-activated protein kinase (AMPK) signaling pathways, as well as small interference RNA, were used to examine the role of these kinases in the CE-induced glucose uptake. The results showed that CE stimulated the phosphorylation of AMPK and acetyl-CoA carboxylase. An AMPK inhibitor and LKB1 siRNA blocked the CE-induced glucose uptake. We also found for the first time that insulin suppressed AMPK activation in the adipocyte. To investigate the effect of CE on type 2 diabetes in vivo, we further performed oral glucose tolerance tests and insulin tolerance tests in type 2 diabetes model rats administered with CE. The CE improved glucose tolerance in oral glucose tolerance tests, but not insulin sensitivity in insulin tolerance test. In summary, these results indicate that CE ameliorates type 2 diabetes by inducing GLUT4 translocation via the AMPK signaling pathway. We also found insulin antagonistically regulates the activation of AMPK.

  13. Flavonoids from Enicostema littorale blume enhances glucose uptake of cells in insulin resistant human liver cancer (HepG2) cell line via IRS-1/PI3K/Akt pathway.

    Science.gov (United States)

    Mokashi, Priyanka; Khanna, Aparna; Pandita, Nancy

    2017-06-01

    Diabetes mellitus has spread over the world with 347 million people affected. Insulin resistance is a main pathogenic event in Type 2 Diabetes Mellitus (T2DM) leading to a reduction in glucose uptake by peripheral tissue and increased hepatic glucose output. In this study, we have isolated four flavonoid rich fractions fraction A (FA), fraction B (FB), fraction C (FC) and fraction D (FD) from Enicostema littorale. All the fractions were preliminary screened for TLC fingerprinting, total flavonoid content. Total eight flavonoids were identified by LC/MS. Insulin resistant HepG2 (IR/HepG2) model was established by inducing insulin resistance in HepG2 cells to investigate the effect of these fractions on IR/HepG2 cell line for their glucose uptake. The results showed the significant dose dependant increase in glucose uptake of cells treated with FD. It showed significant activity at a concentration of 10μg/ml. The LC/MS results of FD demonstrated the presence of C-glycoside Swertisin which could be responsible for the effect. Further, to investigate the mechanism of action, gene expression for insulin receptor substrate 1 (IRS-1), protein kinase B (Akt-2) and glucose transporter 4 (GLUT-4) genes were evaluated by real time PCR. A significant upregulation of these genes was observed in FD treated samples, thereby indicating the enhancement of glucose uptake rate of cells via IRS-1/PI3K/Akt pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Quaternary structures of recombinant, cellular, and serum forms of Thymidine Kinase 1 from dogs and humans

    Directory of Open Access Journals (Sweden)

    Hanan Sharif

    2012-06-01

    Full Text Available Abstract Background Thymidine kinase 1 (TK1 is a salvage enzyme involved in DNA precursor synthesis, and its expression is proliferation dependent. A serum form of TK1 has been used as a biomarker in human medicine for many years and more recently to monitor canine lymphoma. Canine TK1 has not been cloned and studied. Therefore, dog and human TK1 cDNA were cloned and expressed, and the recombinant enzymes characterized. The serum and cellular forms of canine and human TK1 were studied by size-exclusion chromatography and the level of TK1 protein was determined using polyclonal and monoclonal anti-TK1 antibodies. Results Canine TK1 phosphorylated the thymidine (dThd analog 3'-azido-thymidine (AZT as efficiently as it did dThd, whereas AZT phosphorylation by human TK1 was less efficient than that of dThd. Dog TK1 was also more thermostable and pH tolerant than the human enzyme. Oligomeric forms were observed with both enzymes in addition to the tetrameric and dimeric forms. Cellular TK1 was predominantly seen in dimeric and tetrameric forms, in the case of both dog TK1 from MDCK cells and human TK1 from CEM cells. Active serum TK1 was found mainly in a high molecular weight form, and treatment with a reducing agent shifted the high molecular weight complex to lower molecular weight forms with reduced total activity. Western blot analysis demonstrated a polypeptide of 26 kDa (dog and 25 kDa (human for cellular and serum TK1. There was no direct correlation between serum TK1 activity and protein level. It appears that a substantial fraction of serum TK1 is not enzymatically active. Conclusions These results suggest that the serum TK1 protein differs from cellular or recombinant forms, is more active in high molecular weight complexes, and is sensitive to reducing agents. The results presented here provide important information for the future development and use of serum TK1 as a diagnostic biomarker in human and veterinary medicine.

  15. Aqueous fraction of Beta vulgaris ameliorates hyperglycemia in diabetic mice due to enhanced glucose stimulated insulin secretion, mediated by acetylcholine and GLP-1, and elevated glucose uptake via increased membrane bound GLUT4 transporters.

    Science.gov (United States)

    Ul Kabir, Ashraf; Samad, Mehdi Bin; Ahmed, Arif; Jahan, Mohammad Rajib; Akhter, Farjana; Tasnim, Jinat; Hasan, S M Nageeb; Sayfe, Sania Sarker; Hannan, J M A

    2015-01-01

    The study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris. Aqueous fraction of B. Vulgaris extract was the only active fraction (50mg/kg). Plasma insulin level was found to be the highest at 30 mins after B. Vulgaris administration at a dose of 200mg/kg. B. Vulgaris treated mice were also assayed for plasma Acetylcholine, Glucagon Like Peptide-1 (GLP-1), Gastric Inhibitory Peptide (GIP), Vasoactive Intestinal Peptide, Pituitary Adenylate Cyclase-Activating Peptide (PACAP), Insulin Like Growth Factor-1 (IGF-1), Pancreatic Polypeptides (PP), and Somatostatin, along with the corresponding insulin levels. Plasma Acetylcholine and GLP-1 significantly increased in B. Vulgaris treated animals and were further studied. Pharmacological enhancers, inhibitors, and antagonists of Acetylcholine and GLP-1 were also administered to the test animals, and corresponding insulin levels were measured. These studies confirmed the role of acetylcholine and GLP-1 in enhanced insulin secretion (ptransporters were quantified and the subsequent glucose uptake and glycogen synthesis were assayed. We showed that levels of membrane bound GLUT4 transporters, glucose-6-phosphate in skeletal myocytes, activity of glycogen synthase, and level of glycogen deposited in the skeletal muscles all increased (pglucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in the anti-hyperglycemic activity of B. Vulgaris.

  16. Imaging in vivo herpes simplex virus thymidine kinase gene transfer to tumour-bearing rodents using positron emission tomography and [{sup 18}F]FHPG

    Energy Technology Data Exchange (ETDEWEB)

    Hustinx, R.; Shiue, C.Y.; Alavi, A.; Shiue, G.G.; Zhuang, H.; Karp, J.S. [Hospital of the Univ. of Pennsylvania (HUP), Philadelphia (United States). Dept. of Radiology; McDonald, D. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Chemistry; Lanuti, M.; Lambright, E. [Dept. of Surgery, University of Pennsylvania, Philadelphia (United States); Eck, S.L. [Dept. of Medicine, University of Pennsylvania, Philadelphia (United States)

    2001-01-01

    Radiolabelled ganciclovir analogues have shown promise as imaging agents to detect herpes simplex virus thymidine kinase (HSVtk) expression. This study evaluated the use of positron emission tomography (PET) imaging with 9-[(3-[{sup 18}F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([{sup 18}F]FHPG) to assess gene transfer into tumours. HSVtk-positive and HSVtk-negative cell lines were first treated in vitro with [{sup 18}F]FHPG. To assess the efficacy of PET in detecting HSVtk expression following in vivo gene transfer, mice were injected intravenously with an adenovirus encoding HSVtk (Ad.HSVtk), a control vector (Ad.Bgl2) or saline. Subcutaneous human glioma xenografts were grown in mice and treated by direct injection of Ad.HSVtk or Ad.Bgl2. Imaging was performed 48 h after transduction. Similar experiments were performed using Fischer rats implanted with syngeneic tumours. The presence of the HSVtk protein was confirmed by immunohistochemistry. Biodistribution studies were also obtained in 14 naive mice. In vitro studies showed high and specific uptake of [{sup 18}F]FHPG in HSVtk-positive cell lines, with an uptake ratio of up to 27:1. PET imaging and direct counting of major organs demonstrated HSVtk-specific tracer retention. In mice, HSVtk-positive tumours retained 3.4% dose/gram as compared to 0.6% for control tumours (P=0.03). They were clearly seen on the PET images as early as 100 min post injection. Similar results were obtained with syngeneic rat tumours. Biodistribution studies demonstrated the rapid distribution and clearance of the tracer in all major organs. Our results demonstrate that PET imaging of HSVtk gene transfer to tumours is feasible and is highly specific for HSVtk expression. (orig.)

  17. A human osteosarcoma cell line expressing herpes simplex type-1 thymidine kinase: studies with radiolabeled (E)-5-(2-iodovinyl)-2'-fluoro-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Kevin W. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); Duan Weili [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); Knaus, Edward E. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); McEwan, Alexander J.B. [Department of Radiology and Diagnostic Imaging, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 2N8 (Canada); Wiebe, Leonard I. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada)]. E-mail: leonard.wiebe@ualberta.ca

    2005-07-01

    Introduction: (E)-5-(2-Iodovinyl)-2'-fluoro-2'-deoxyuridine (IVFRU) is a pyrimidine nucleoside analogue that accumulates selectively in murine cells expressing herpes simplex type-1 thymidine kinase (HSV-1 TK). The uptake of [{sup 125}I]IVFRU in human 143B osteosarcoma cells transduced with a retroviral vector bearing the HSV-1 TK gene (143B-LTK cells) is now reported. Methods: HSV-1 TK gene expression in 143B-LTK cells was confirmed by Western blotting and reverse transcriptase (RT)-PCR. Cell and subcellular uptake of [{sup 125}I]IVFRU was determined in cell culture, and whole body biodistribution after intravenous injection of [{sup 125}I]IVFRU was determined using nude mice bearing implanted 143B or 143B-LTK tumors. Results: Although IVFRU was less toxic to the human cell line expressing HSV-1 TK (143B-LTK) than ganciclovir, both IVFRU and ganciclovir were not toxic to the cell line not expressing HSV-1 TK (143B). When cells were exposed to [{sup 125}I]IVFRU in vitro, only the 143B-LTK cells accumulated radioactivity. The acid-soluble fraction from 143B-LTK cell lysates contained 8-fold greater activity than the acid-insoluble fraction after an 8-h exposure to [{sup 125}I]IVFRU. Biodistribution of [{sup 125}I]IVFRU in nude mice bearing subcutaneous 143B and 143B-LTK tumors revealed widespread distribution of the nucleoside in vivo but with specific localization in 143B-LTK tumors. Conclusion: The underlying biochemical process of metabolic entrapment of IVFRU in human osteosarcoma cells expressing HSV-1 TK is responsible for selective localization in these cells. The differences in subcellular distribution into the nucleic acid fraction, and in cytotoxicity, reflect the importance of cell type and lineage as determinants of the performance of gene imaging radiopharmaceuticals.

  18. Use of Fe-Impregnated Biochar To Efficiently Sorb Chlorpyrifos, Reduce Uptake by Allium fistulosum L., and Enhance Microbial Community Diversity.

    Science.gov (United States)

    Tang, Xiao-Yan; Huang, Wen-Da; Guo, Jing-Jing; Yang, Yang; Tao, Ran; Feng, Xu

    2017-07-05

    Fe-impregnated biochar was assessed as a method to remove the pesticide pollutant chlorpyrifos, utilizing biochar/FeOx composite synthesized via chemical coprecipitation of Fe(3+)/Fe(2+) onto Cyperus alternifolius biochar. Fe-impregnated biochar exhibited a higher sorption capacity than pristine biochar, resulting in more efficient removal of chlorpyrifos from water. Soil was dosed with pristine or Fe-impregnated biochar at 0.1 or 1.0% w/w, to evaluate chlorpyrifos uptake in Allium fistulosum L. (Welsh onion). The results showed that the average concentration of chlorpyrifos and its degradation product, 3,5,6-trichloro-2-pyridinol (TCP), decreased in A. fistulosum L. with increased levels of pristine biochar and Fe-biochar. Fe-biochar was found to be more effective in reducing the uptake of chlorpyrifos by improving the sorption ability and increasing plant root iron plaque. Bioavailability of chlorpyrifos is reduced with both biochar and Fe-biochar soil dosing; however, the greatest persistence of chlorpyrifos residues was observed with 1.0% pristine biochar. Microbial community analysis showed Fe-biochar to have a positive impact on the efficiency of chlorpyrifos degradation in soils, possibly by altering microbial communities.

  19. Detection of bovine herpesvirus 4 glycoprotein B and thymidine kinase DNA by PCR assays in bovine milk

    NARCIS (Netherlands)

    Wellenberg, G.J.; Verstraten, E.; Belak, S.; Verschuren, S.B.E.; Rijsewijk, F.A.M.; Peshev, R.; Oirschot, van J.T.

    2001-01-01

    A polymerase chain reaction (PCR) assay was developed to detect bovine herpesvirus 4 (BHV4) glycoprotein B (gB) DNA, and a nested-PCR assay was modified for the detection of BHV4 thymidine kinase (TK) DNA in bovine milk samples. To identify false-negative PCR results, internal control templates were

  20. Prognostic significance of numeric aberrations of genes for thymidylate synthase, thymidine phosphorylase and dihydrofolate reductase in colorectal cancer

    DEFF Research Database (Denmark)

    Jensen, Søren Astrup; Vainer, B.; Witton, C.J.

    2008-01-01

    BACKGROUND: Most human cancer cells have structural aberrations of chromosomal regions leading to loss or gain of gene specific alleles. This study aimed to assess the range of gene copies per nucleus of thymidylate synthase (TYMS), thymidine phosphorylase (TP) and dihydrofolate reductase (DHFR...

  1. Isolation of a human lymphoblastoid line heterozygous at the thymidine kinase locus: possibility for a rapid human cell mutation assay

    Energy Technology Data Exchange (ETDEWEB)

    Skopek, T.R.; Liber, H.L.; Penman, B.W.; Thilly, W.G.

    1978-09-29

    A thymidine kinase heterozygote designated H2BT has been isolated from the human lymphoblast line HH4. Significant increase in the trifluorothymidine-resistant fraction was observed in the new cell line following treatment with the mutagens ICR-191 and butylmethansulfonate. Phenotypic expression was complete forty-eight hours after treatment.

  2. Secretion of thymidine kinase to increase the effectivity of suicide gene therapy results in the loss of enzymatic activity

    NARCIS (Netherlands)

    Beerens, A. M. J.; Rots, M. G.; Bermudez, B.; De Vries, E. F. J.; Haisma, H. J.

    2008-01-01

    Low efficiency of gene transfer is one of the major limitations of gene therapy. A solution to this problem may be transmission; by modification of the transgene, the gene product can be secreted and internalized by the surrounding cells. Cancer gene therapy using the herpes simplex thymidine kinase

  3. Development and trial of a bovine herpesvirus 1-thymidine kinase deletion virus as a vaccine.

    Science.gov (United States)

    Smith, G A; Young, P L; Rodwell, B J; Kelly, M A; Storie, G J; Farrah, C A; Mattick, J S

    1994-03-01

    An Australian bovine herpesvirus 1 (BHV1) isolate with a defined (427 base pair) deletion in the protein coding region of the thymidine kinase gene was obtained by standard marker rescue procedures. After selection in the presence of the nucleotide analogue 5'-iodo-deoxy-uridine the virus was analysed by hybridisation with three differential oligonucleotide probes, restriction endonuclease profile studies and DNA sequence analysis. The virus elicited an immune response in recipient animals after either intramuscular or intravenous administration and produced no significant deleterious side-effects when administered at a dose sufficient to stimulate the host immune response. The safety and immunogenicity of the recombinant BHV1 virus 39B1 were similar to those reported for other registered BHV1 vaccines and the virus would appear to be suitable for the production of a vaccine seed lot and more exhaustive field trials as a prelude to commercial vaccine production and registration.

  4. Studies of the cytosolic thymidine kinase in human cells and comparison to the recombinantly expressed enzyme

    DEFF Research Database (Denmark)

    Kock Jensen, Helle

    Thymidine kinase (TK) is a key enzyme in the salvage pathway of the nucleoside metabolism catalyzing the first phosphorylation step in TTP synthesis. Human cytosolic TK (TKl) is highly cell cycle regulated. TKl is regulated on many different levels of expression and isoforms with altered enzymatic...... properties are found in cancer cells. Investigation of these factors offers possibilities to understand the molecular background for TKl expression including to clarify general regulation patterns. It also gives valuable information for constructing new nucleoside analogs for the therapy of cancer and virus...... infections. In the first part of the present investigation a sensitive test for quantitating TKl mRNA (competitive PCR) is developed and the results show that PHA stimulated lymphocytes reveal the same pattern concerning expression of TKl mRNA and TKl enzyme activity as serum-stimulated cells. This pattern...

  5. A pseudoreceptor modelling study of the varicella-zoster virus and human thymidine kinase binding sites

    Science.gov (United States)

    Greenidge, Paulette A.; Merz, Alfred; Folkers, Gerd

    1995-12-01

    A representative range of pyrimidine nucleoside analogues that are known to inhibit herpes simplex virus (HSV) replication have been used to construct receptor binding site models for the varicella-zoster virus (VZV), thymidine kinase (TK) and human TK1. Given a set of interacting ligands, superimposed in such a manner as to define a pharmacophore, the pseudoreceptor modelling technique Yak provides a means of building binding site models of macromolecules for which no three-dimensional experimental structures are available. Once the models have been evaluated by their ability to reproduce experimental binding data [Vedani et al., J. Am. Chem. Soc., 117 (1995) 4987], they can be used for predictive purposes. Calculated and experimental values of relative binding affinity are compared. Our models suggest that the substitution of one residue may be sufficient to determine ligand subtype affinity.

  6. Use of Thymidine Kinase Recombinant Adenovirus and Ganciclovir Mediated Mouse Liver Preconditioning for Hepatocyte Xenotransplantation.

    Science.gov (United States)

    Moreno, Daniel; Neri, Leire; Vicente, Eva; Vales, Africa; Aldabe, Rafael

    2017-01-01

    Hepatocyte transplantation is the best approach to maintain and propagate differentiated hepatocytes from different species. Host liver has to be adapted for transplanted hepatocytes productive engraftment and proliferation being required a chronic liver injury to eliminate host hepatocytes and provide a proliferative advantage to the transplanted hepatocytes. Most valuable mouse models for xenograft hepatocyte transplantation are based on genetically modified animals to cause a chronic liver damage and to limit host hepatocyte regeneration potential. We present a methodology that generates a chronic liver damage and can be applied to any host mouse strain and animal species based on the inoculation of a recombinant adenovirus to express herpes simplex thymidine kinase in host hepatocytes sensitizing them to ganciclovir treatment. This causes a prolonged liver damage that allows hepatocyte transplantation and generation of regenerative nodules in recipient mouse liver integrated by transplanted cells and host sinusoidal. Obtained chimeric animals maintain functional chimeric nodules for several weeks, ready to be used in any study.

  7. A phase II trial of thymidine and carboplatin for recurrent malignant glioma: a North American Brain Tumor Consortium Study.

    Science.gov (United States)

    Robins, H. Ian; Chang, Susan M.; Prados, Michael D.; Yung, W. K. Alfred; Hess, Kenneth; Schiff, David; Greenberg, Harry; Fink, Karen; Nicolas, Kelly; Kuhn, John G.; Cloughesy, Timothy; Junck, Larry; Mehta, Minesh

    2002-01-01

    This phase II study in recurrent high-grade glioma evaluated the response rate, toxicities, and time to treatment failure of high-dose carboplatin modulated by a 24-h infusion of thymidine (75 g/m(2)). The trial was based on preclinical data and a prior phase I study ( J. Clin. Oncol. 17, 2922-2931, 1999); a phase II recurrent high-grade glioma study was initiated in July of 1998. Thymidine was given over 24 h; carboplatin was given over 20 min at hour 20 of the thymidine infusion. The starting dose of carboplatin had a value of 7 for the area under the curve (AUC), with allowance for dose escalation of 1 AUC unit per cycle if grade 2 toxicity was observed. Treatment cycles were repeated every 4 weeks. Accrual as of September 1999 was 45 patients [4 were unevaluable]: 76% with glioblastoma multiforme (GBM), 20% with anaplastic oligodendroglioma, 2% with mixed type, and 2% with anaplastic astrocytoma. Most patients had prior chemotherapy (78%). As observed in the earlier phase I study (in which carboplatin pharmacokinetics were unaltered by thymidine or antiseizure medications), thymidine was myeloprotective, resulting in a minimal need for dose reduction for patients having a >2 grade toxicity (in only 4% of the courses of treatment). Of 101 total courses, the number of courses (at the AUCs) was 3 (5), 4 (6), 58 (7), 20 (8), 11 (9), and 5 (10). Grade 3 nonhematologic toxicities included headache (4%), altered consciousness (3%), fatigue (1%), and nausea (3%). Responses included 2 partial (1 oligodendroglioma, 1 GBM; 5%); 3 minor (1 anaplastic astrocytoma, 2 GBM; 7.3%); 6 stable disease (14.6%); and 30 progressive disease (73.2%). For GBM patients, median survival was 23 weeks (with a 95% confidence interval of 20 to 50 weeks), and progression-free survival was 8 weeks (with a 95% confidence interval of 7-16 weeks). These results in GBM were comparable to other phase II GBM trials and thus do not represent a therapeutic advance in the treatment of GBM. Taken

  8. Structure of vaccinia virus thymidine kinase in complex with dTTP: insights for drug design

    Directory of Open Access Journals (Sweden)

    Balzarini Jan

    2006-10-01

    Full Text Available Abstract Background Development of countermeasures to bioterrorist threats such as those posed by the smallpox virus (variola, include vaccination and drug development. Selective activation of nucleoside analogues by virus-encoded thymidine (dThd kinases (TK represents one of the most successful strategies for antiviral chemotherapy as demonstrated for anti-herpes drugs. Vaccinia virus TK is a close orthologue of variola TK but also shares a relatively high sequence identity to human type 2 TK (hTK, thus achieving drug selectivity relative to the host enzyme is challenging. Results In order to identify any differences compared to hTK that may be exploitable in drug design, we have determined the crystal structure of VVTK, in complex with thymidine 5'-triphosphate (dTTP. Although most of the active site residues are conserved between hTK and VVTK, we observe a difference in conformation of residues Asp-43 and Arg-45. The equivalent residues in hTK hydrogen bond to dTTP, whereas in subunit D of VVTK, Asp-43 and Arg-45 adopt a different conformation preventing interaction with this nucleotide. Asp-43 and Arg-45 are present in a flexible loop, which is disordered in subunits A, B and C. The observed difference in conformation and flexibility may also explain the ability of VVTK to phosphorylate (South-methanocarbathymine whereas, in contrast, no substrate activity with hTK is reported for this compound. Conclusion The difference in conformation for Asp-43 and Arg-45 could thus be used in drug design to generate VVTK/Variola TK-selective nucleoside analogue substrates and/or inhibitors that have lower affinity for hTK.

  9. Clinical significance of thymidine kinase in Egyptian children with acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Adel A Hagag

    2015-01-01

    Full Text Available Background: Acute lymphoblastic leukemia (ALL is the most common childhood malignancy, representing one-third of pediatric cancers. Thymidine kinase-1 (TK-1 is expressed in proliferating cells so elevated TK-1 indicates active tumor growth. Objective: To study the clinical significance of TK-1 in children with ALL. Patients and Methods: This study was carried out on 40 children with newly diagnosed ALL who were admitted to Oncology Unit, Pediatric department, Tanta University (26 males and 14 females with their ages ranged from 4 to 10 years and 30 healthy children of matched age and sex as a control group. For all patients the following were done: Complete blood picture, bone marrow examination, immunophenotyping and TK-1 serum levels. Results: Mean TK-1 level was significantly higher in patients at diagnosis than controls and significantly higher in patients with unfavorable outcome than patients with favorable outcome. Mean TK-1 level was significantly higher in patients in relapse than patients in remission and controls. No significant differences in mean TK-1 level between patients in remission and controls. There were statistically significant differences in disease free survival and overall survival between patients with favorable and unfavorable outcome. Conclusion: From this study we concluded that TK is a helpful marker in diagnosis and follow-up of patients with ALL. Recommendations: Thymidine kinase-1 should be routinely assessed at diagnosis and during follow-up in ALL patients for better diagnostic and prognostic assessment and should be taken in consideration in designing future therapeutic strategies based on patients-specific risk factors.

  10. Molecular Delivery System for Antisense Oligonucleotides: Enhanced Effectiveness of Antisense Oligonucleotides by HVJ-liposome Mediated Transfer.

    Science.gov (United States)

    Morishita; Gibbons; Horiuchi; Nakajima; Ellison; Lee; Kaneda; Ogihara; Dzau

    1997-07-01

    BACKGROUND: The effectiveness of antisense oligodeoxynucleotides for in vitro and in vivo studies is limited by a low efficiency of cellular uptake and instability due to degradation by nucleases. To overcome some of these problems, we recently developed a transfer method that utilizes inactivated Sendai virus (hemagglutinating virus of Japan [HVJ]) complexed with liposomes to deliver antisense oligodeoxynucleotides. In this study, we compared the effectiveness of the HVJ-liposome method versus a cationic liposome method versus passive uptake to deliver antisense oligodeoxynucleotides against basic fibroblast growth factor on angiotensin (Ang) II-induced rat vascular smooth muscle cell growth. METHODS AND RESULTS: Twenty to twenty-eight hours after transfection, antisense fibroblast growth factor oligodeoxynucleotides introduced by passive uptake and HVJ-liposome method decreased basal DNA synthesis significantly as compared to the sense, control, and scrambled oligodeoxynucleotides groups; however, 60-68 hours after transfection, only antisense fibroblast growth factor oligodeoxynucleotides transduced by the HVJ-liposome method resulted in a significant inhibition of DNA synthesis under basal and Ang II-(10(-;6)M) stimulated conditions. The IC(25) of oligodeoxynucleotides assessed by the inhibition of thymidine incorporation was significantly lower using the HVJ-liposome method than those using the other transfer methods. To clarify the mechanisms of cellular uptake of oligodeoxynucleotides with the HVJ-liposome method, we studied the cellular fate of fluorescein isothiocyanate (FITC)-labeled oligodeoxynucleotides FITC-oligodeoxynucleotides was localized in nuclei at 5 minutes after transfection with the HVJ-liposome method. In contrast, FITC-oligodeoxynucleotides introduced by passive uptake was detected in nonnuclear cellular compartments, possibly endosomes, but not the nuclei. Cellular fluorescence of oligodeoxynucleotides introduced by passive uptake

  11. Clinical breast examination as the recommended breast cancer screening modality in a rural community in Malaysia; what are the factors that could enhance its uptake?

    Directory of Open Access Journals (Sweden)

    Nik Daliana Nik Farid

    Full Text Available Breast cancer is the most common cause of deaths and the most frequently diagnosed cancer among women worldwide. This study aimed to determine the prevalence of breast cancer screening, specifically on clinical breast examination, and the predictors of its uptake among women in Malaysia. A cross-sectional study was carried out in five selected districts whereby women aged between 20 to 64 years old, from a total of 1000 households were interviewed. A total of 1192 women responded to the survey of which 53.3% reported had ever done clinical breast examination. Significant associations with clinical breast examination were noted for income and distance from the hospital. These factors should be considered in developing interventions aimed at promoting clinical breast examination. In particular, healthcare providers should be proactive in raising awareness about clinical breast examination among women in Malaysia.

  12. Enhanced uptake and translocation of arsenic in Cretan brake fern (Pteris cretica L.) through siderophorearsenic complex formation with an aid of rhizospheric bacterial activity.

    Science.gov (United States)

    Jeong, Seulki; Moon, Hee Sun; Nam, Kyoungphile

    2014-09-15

    Siderophores, produced by Pseudomonas aeruginosa, released slightly more Fe (53.6 μmol) than that chelated by ethylenediaminetetraacetic acid (EDTA; i.e. 43.7 μmol) in batch experiment using As-adsorbed ferrihydrite. More importantly, about 1.79 μmol of As was found to be associated with siderophores in the aqueous phase due to siderophore-As complex formation when siderophores were used to release As from ferrihydrite. In contrast, As was not detected in the aqueous phase when EDTA was used, probably due to the readsorption of released As to ferrihydrite. A series of pot experiment was conducted to investigate the effect of siderophores as a microbial iron-chelator on As uptake by Cretan brake fern (Pteris cretica L.) during phtoextraction. Results revealed that P. cretica, a known As hyperaccumulator, grown in the siderophore-amended soil showed about 3.7 times higher As uptake (5.62 mg-Asg(-1)-plant) than the plant grown in the EDTA-treated soil (1.51 mg-Asg(-1)-plant). In addition, As taken up by roots of P. cretica in the presence of siderophores seemed to be favorably translocated to shoots (i.e. stems and leaves). About 79% of the accumulated As was detected in the shoots in the presence of siderophores after ten weeks. Fluorescence microscopic analysis confirmed that As in the roots was delivered to the leaves of P. cretica as a siderophore-As complex. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Antioxidant rich flavonoids from Oreocnide integrifolia enhance glucose uptake and insulin secretion and protects pancreatic β-cells from streptozotocin insult

    Directory of Open Access Journals (Sweden)

    Ansarullah

    2011-12-01

    Full Text Available Abstract Background Insulin deficiency is the prime basis of all diabetic manifestations and agents that can bring about insulin secretion would be of pivotal significance for cure of diabetes. To test this hypothesis, we carried out bioactivity guided fractionation of Oreocnide integrifolia (Urticaceae; a folklore plant consumed for ameliorating diabetic symptoms using experimental models. Methods We carried out bioassay guided fractionation using RINmF and C2C12 cell line for glucose stimulated insulin secretion (GSIS and glucose uptake potential of fractions. Further, the bioactive fraction was challenged for its GSIS in cultured mouse islets with basal (4.5 mM and stimulated (16.7 mM levels of glucose concentrations. The Flavonoid rich fraction (FRF was exposed to 2 mM streptozotocin stress and the anti-ROS/RNS potential was evaluated. Additionally, the bioactive fraction was assessed for its antidiabetic and anti-apoptotic property in-vivo using multidose streptozotocin induced diabetes in BALB/c mice. Results The results suggested FRF to be the most active fraction as assessed by GSIS in RINm5F cells and its ability for glucose uptake in C2C12 cells. FRF displayed significant potential in terms of increasing intracellular calcium and cAMP levels even in presence of a phosphodiesterase inhibitor, IBMX in cultured pancreatic islets. FRF depicted a dose-dependent reversal of all the cytotoxic manifestations except peroxynitrite and NO formation when subjected in-vitro along with STZ. Further scrutinization of FRF for its in-vivo antidiabetic property demonstrated improved glycemic indices and decreased pancreatic β-cell apoptosis. Conclusions Overall, the flavonoid mixture has shown to have significant insulin secretogogue, insulinomimetic and cytoprotective effects and can be evaluated for clinical trials as a therapeutant in the management of diabetic manifestations.

  14. Thyroid Scan and Uptake

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    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... code: Phone no: Thank you! Do you have a personal story about radiology? Share your patient story ...

  15. Thyroid Scan and Uptake

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    Full Text Available ... known as a thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. ... eating can affect the accuracy of the uptake measurement. Jewelry and other metallic accessories should be left ...

  16. Thyroid Scan and Uptake

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    Full Text Available ... limitations of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... top of page What are some common uses of the procedure? The thyroid scan is used to ...

  17. Thyroid Scan and Uptake

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    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... of page What are some common uses of the procedure? The thyroid scan is used to determine ...

  18. Thyroid Scan and Uptake

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    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ...

  19. Thyroid Scan and Uptake

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    Full Text Available ... the limitations of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid ... body converts food to energy. top of page What are some common uses of the procedure? The ...

  20. Thyroid Scan and Uptake

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    Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

  1. Phenyl 1,2,3-triazole-thymidine ligands stabilize G-quadruplex DNA, inhibit DNA synthesis and potentially reduce tumor cell proliferation over 3'-azido deoxythymidine.

    Directory of Open Access Journals (Sweden)

    Jerald Mahesh Kumar

    Full Text Available Triazoles are known for their non-toxicity, higher stability and therapeutic activity. Few nucleoside (L1, L2 and L3 and non-nucleoside 1,2,3-triazoles (L4-L14 were synthesised using click chemistry and they were screened for tumor cell cytotoxicity and proliferation. Among these triazole ligands studied, nucleoside ligands exhibited higher potential than non-nucleoside ligands. The nucleoside triazole analogues, 3'-Phenyl-1,2,3- triazole-thymidine (L2 and 3'-4-Chlorophenyl-1,2,3-triazole-thymidine (L3, demonstrated higher cytotoxicity in tumor cells than in normal cells. The IC₅₀ value for L3 was lowest (50 µM among the ligands studied. L3 terminated cell cycle at S, G2/M phases and enhanced sub-G1 populations, manifesting induction of apoptosis in tumor cells. Confocal studies indicated that nucleoside triazole ligands (L2/L3 cause higher DNA fragmentation than other ligands. Preclinical experiments with tumor-induced mice showed greater reduction in tumor size with L3. In vitro DNA synthesis reaction with L3 exhibited higher DNA synthesis inhibition with quadruplex forming DNA (QF DNA than non quadruplex forming DNA (NQF DNA. T(m of quadruplex DNA increased in the presence of L3, indicating its ability to enhance stability of quadruplex DNA at elevated temperature and the results indicate that it had higher affinity towards quadruplex DNA than the other forms of DNA (like dsDNA and ssDNA. From western blot experiment, it was noticed that telomerase expression levels in the tissues of tumor-induced mice were found to be reduced on L3 treatment. Microcalorimetry results emphasise that two nucleoside triazole ligands (L2/L3 interact with quadruplex DNA with significantly higher affinity (K(d≈10⁻⁷ M. Interestingly the addition of an electronegative moiety to the phenyl group of L2 enhanced its anti-proliferative activity. Though IC₅₀ values are not significantly low with L3, the studies on series of synthetic 1,2,3-triazole ligands

  2. Evaluation of F-18-labeled 5-iodocytidine ({sup 18}F-FIAC) as a new potential positron emission tomography probe for herpes simplex virus type 1 thymidine kinase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Pei-Chia; Wu, Chun-Yi; Chang, Wen-Yi; Chang, Wei-Ting [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 11221, Taiwan (China); Alauddin, Mian [Department of Experimental Diagnostic Imaging, MD Anderson Cancer Center, University of Texas, TX, 77054 (United States); Liu, Ren-Shan [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 11221, Taiwan (China); Department of Nuclear Medicine, Faculty of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan (China); Department of Nuclear Medicine and National PET/Cyclotron Center, Taipei Veterans General Hospital, Taipei, 11217, Taiwan (China); Lin, Wuu-Jyh [Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, 32546, Taiwan (China); Chen, Fu-Du [College of Health and Leisure Science, TransWorld University, Yunlin, 64063, Taiwan (China); Chen, Chuan-Lin, E-mail: clchen2@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 11221, Taiwan (China); Wang, Hsin-Ell, E-mail: hewang@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 11221, Taiwan (China)

    2011-10-15

    Objective: Herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene in combination with radiolabeled nucleoside substrates is the most widely used reporter system. This study characterized 1-(2'-deoxy-2'-[{sup 18}F]fluoro-{beta}-D-arabinofuranosyl)-5-iodocytosine ({sup 18}F-FIAC) as a new potential positron emission tomography (PET) probe for HSV1-tk gene imaging and compared it with 2'-deoxy-2'-[{sup 18}F]fluoro-5-iodo-1-{beta}-D-arabinofuranosyluracil ({sup 18}F-FIAU) and 2'-deoxy-2'-[{sup 18}F]fluoro-5-ethyl-1-{beta}-D-arabinofuranosyluracil({sup 18}F-FEAU) (thymidine analogues) in an NG4TL4-WT/STK sarcoma-bearing mouse model. Methods: A cellular uptake assay, biodistribution study, radioactive metabolites assay and microPET imaging of NG4TL4-WT/STK tumor-bearing mice post administration of {sup 18}F-FIAC, {sup 18}F-FIAU and {sup 18}F-FEAU were conducted to characterize the biological properties of these tracers. Results: Highly specific uptake of {sup 18}F-FIAC, {sup 18}F-FIAU and {sup 18}F-FEAU in tk-transfected [tk(+)] cells was observed. The tk(+)-to-tk(-) cellular uptake ratio after a 2-h incubation was 66.6{+-}25.1, 76.3{+-}18.2 and 247.2{+-}37.2, respectively. In biodistribution studies, {sup 18}F-FIAC showed significant tk(+) tumor specificity (12.6; expressed as the tk(+)-to-tk(-) tumor uptake ratio at 2 h postinjection) comparable with {sup 18}F-FIAU (15.8) but lower than {sup 18}F-FEAU (48.0). The results of microPET imaging also revealed the highly specific accumulation of these three radioprobes in the NG4TL4-tk(+) tumor. Conclusion: Our findings suggested that the cytidine analogue {sup 18}F-FIAC is a new potential PET probe for the imaging of HSV1-tk gene expression. {sup 18}F-FIAC may be regarded as the prodrug of {sup 18}F-FIAU in vivo.

  3. Enhanced cellular uptake and phototoxicity of Verteporfin-conjugated gold nanoparticles as theranostic nanocarriers for targeted photodynamic therapy and imaging of cancers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Linlin [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin 300384 (China); Graduate School of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Tae-Hyun; Kim, Hae-Won [Department of Nanobiomedical Science, Dankook University Graduate School, Cheonan 330-714 (Korea, Republic of); Institute of Tissue Regeneration Engineering (ITREN) & College of Dentistry, Dankook University, Cheonan 330-714 (Korea, Republic of); Ahn, Jin-Chul [Department of Biomedical Science, College of Medicine, Dankook University, Cheonan, 330-714 (Korea, Republic of); Kim, So Yeon, E-mail: kimsy@cnu.ac.kr [Graduate School of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Chemical Engineering Education, College of Education, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2016-10-01

    Activatable theranostics with the capacity to respond to a given stimulus have recently been intensively explored to develop more specific, individualized therapies for various diseases, and to combine diagnostic and therapeutic capabilities into a single agent. In this work, we designed tumor-targeting ligand-conjugated block copolymer-gold nanoparticle (AuNP) conjugates as multifunctional nanocarriers of the hydrophobic photosensitizer (PS), verteporfin (Verte), for simultaneous photodynamic therapy and imaging of cancers. Folic acid (FA)-conjugated block copolymers composed of polyethylene glycol (PEG) and poly-β-benzyl-L-aspartate (PBLA) were attached to citrate-stabilized AuNPs through a bidentate dihydrolipoic acid (DHLA) linker. The resulting AuNP conjugates (FA-PEG-P(Asp-Hyd)-DHLA-AuNPs) were significantly more stable than unmodified AuNPs, and their optical properties were not affected by pH. The hydrophobic PS, Verte, was covalently incorporated onto the surfaces of the AuNP conjugates through a pH-sensitive linkage, which increased the water solubility of Verte from < 1 μg/ml to > 2000 μg/ml. The size of FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte as determined by light-scattering measurements was about 110.3 nm, and FE-SEM and FE-TEM images showed that these nanoparticles were spherical and showed adequate dispersivity after modification. In particular, an in vitro cell study revealed high intracellular uptake of FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte (about 98.62%) and marked phototoxicity after laser irradiation compared with free Verte. These results suggest that FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte has great potential as an effective nanocarrier for dual imaging and photodynamic therapy. - Highlights: • We designed theranostic nanocarriers for photodynamic therapy and imaging of cancers. • AuNP conjugates had a spherical shape and a narrow size distribution with a mean diameter of 110.3 nm. • Cellular uptake of free Verte was 18.86%, whereas that of Au

  4. Cyclic RGD peptide-modified liposomal drug delivery system for targeted oral apatinib administration: enhanced cellular uptake and improved therapeutic effects.

    Science.gov (United States)

    Song, Zhiwang; Lin, Yun; Zhang, Xia; Feng, Chan; Lu, Yonglin; Gao, Yong; Dong, Chunyan

    2017-01-01

    Apatinib is an oral tyrosine kinase inhibitor, which selectively targets vascular endothelial growth factor receptor 2 and has the potential to treat many tumors therapeutically. Cyclic arginylglycylaspartic acid (cRGD)- and polyethylene glycol (PEG)-modified liposomes (cRGD-Lipo-PEG) were constructed to act as a targeted delivery system for the delivery of apatinib to the human colonic cancer cell line, HCT116. These cRGD-modified liposomes specifically recognized integrin α v β 3 and exhibited greater uptake efficiency with respect to delivering liposomes into HCT116 cells when compared to nontargeted liposomes (Lipo-PEG), as well as greater death of tumor cells and apoptosis. The mechanism by which cRGD-Lipo-PEG targets cells was elucidated further with competition assays. To determine the anticancer efficacy in vivo, nude mice were implanted with HCT116 xenografts and treated with apatinib-loaded liposomes or free apatinib intravenously or via intragastric administration. The active and passive targeting of cRGD-Lipo-PEG led to significant tumor treatment targeting ability, better inhibition of tumor growth, and less toxicity when compared with treatments using uncombined apatinib. The results presented strongly support the case for cRGD-Lipo-PEG representing a targeted delivery system for apatinib in the treatment of colonic cancer.

  5. Silicon occurrence, uptake, transport and mechanisms of heavy metals, minerals and salinity enhanced tolerance in plants with future prospects: A review.

    Science.gov (United States)

    Imtiaz, Muhammad; Rizwan, Muhammad Shahid; Mushtaq, Muhammad Adnan; Ashraf, Muhammad; Shahzad, Sher Muhammad; Yousaf, Balal; Saeed, Dawood Anser; Rizwan, Muhammad; Nawaz, Muhammad Azher; Mehmood, Sajid; Tu, Shuxin

    2016-12-01

    Recently, heavy metals pollution due to industrialization and urbanization, use of untreated wastewater and unreasonable use of pesticides and fertilizers is increasing rapidly, resulting in major threat to the environment and contaminate soils. Silicon (Si) is the second most abundant element in the earth crust after oxygen. Although it's higher accumulation in plants, yet Si has not been listed as essential nutrient however, considered as beneficial element for growth of plants particularly in stressed environment. Research to date has demonstrated that silicon helps the plants to alleviate the various biotic and abiotic stresses. This review article presents a comprehensive update about Si and heavy metals, minerals and salinity stresses, and contained the progress about Si so far done worldwide in the light of previous studies to evaluate the ecological importance of Si. Moreover, this review will also be helpful to understand the Si uptake ability and its benefits on plants grown under stressed environment. Further research needs for Si-mediated mitigation of heavy metals and mineral nutrients stresses are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Aqueous fraction of Beta vulgaris ameliorates hyperglycemia in diabetic mice due to enhanced glucose stimulated insulin secretion, mediated by acetylcholine and GLP-1, and elevated glucose uptake via increased membrane bound GLUT4 transporters.

    Directory of Open Access Journals (Sweden)

    Ashraf Ul Kabir

    Full Text Available The study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris.Aqueous fraction of B. Vulgaris extract was the only active fraction (50mg/kg. Plasma insulin level was found to be the highest at 30 mins after B. Vulgaris administration at a dose of 200mg/kg. B. Vulgaris treated mice were also assayed for plasma Acetylcholine, Glucagon Like Peptide-1 (GLP-1, Gastric Inhibitory Peptide (GIP, Vasoactive Intestinal Peptide, Pituitary Adenylate Cyclase-Activating Peptide (PACAP, Insulin Like Growth Factor-1 (IGF-1, Pancreatic Polypeptides (PP, and Somatostatin, along with the corresponding insulin levels. Plasma Acetylcholine and GLP-1 significantly increased in B. Vulgaris treated animals and were further studied. Pharmacological enhancers, inhibitors, and antagonists of Acetylcholine and GLP-1 were also administered to the test animals, and corresponding insulin levels were measured. These studies confirmed the role of acetylcholine and GLP-1 in enhanced insulin secretion (p<0.05. Principal signaling molecules were quantified in isolated mice islets for the respective pathways to elucidate their activities. Elevated concentrations of Acetylcholine and GLP-1 in B. Vulgaris treated mice were found to be sufficient to activate the respective pathways for insulin secretion (p<0.05. The amount of membrane bound GLUT1 and GLUT4 transporters were quantified and the subsequent glucose uptake and glycogen synthesis were assayed. We showed that levels of membrane bound GLUT4 transporters, glucose-6-phosphate in skeletal myocytes, activity of glycogen synthase, and level of glycogen deposited in the skeletal muscles all increased (p<0.05.Findings of the present study clearly prove the role of Acetylcholine and GLP-1 in the Insulin secreting activity of B. Vulgaris. Increased glucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in the anti-hyperglycemic activity of B. Vulgaris.

  7. 5-[{sup 18}F]Fluoroalkyl pyrimidine nucleosides: probes for positron emission tomography imaging of herpes simplex virus type 1 thymidine kinase gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Chacko, Ann-Marie [Institute for Environmental Medicine, Targeted Therapeutics Program, University of Pennsylvania, Philadelphia, PA 19104 (United States); Blankemeyer, Eric; Lieberman, Brian P.; Qu, Wenchao [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)], E-mail: kunghf@gmail.com

    2009-01-15

    Introduction: The preliminary in vivo evaluation of novel 5-[{sup 18}F]fluoroalkyl-2'-deoxyuridines ([{sup 18}F]FPrDU, [{sup 18}F]FBuDU, [{sup 18}F]FPeDU; [{sup 18}F]1a-c, respectively) and 2'-fluoro-2'-deoxy-5-[{sup 18}F]fluoroalkyl-1-{beta}-D-arabinofuranosyl uracils ([{sup 18}F]FFPrAU, [{sup 18}F]FFBuAU, [{sup 18}F]FFPeAU; [{sup 18}F]1d-f, respectively) as probes for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene expression is described. Methods: [{sup 18}F]1a-f were successfully synthesized by a rapid and efficient two-step one-pot nucleophilic fluorination reaction using 5-O-mesylate precursors and [{sup 18}F]F{sup -}. For in vivo studies, tumor xenografts were grown in nude mice by implanting RG2 cells stably expressing HSV1-tk (RG2TK+) and wild-type cells (RG2). Results: Biodistribution studies at 2 h pi revealed that the uptake of [{sup 18}F]1a-b and [{sup 18}F]1d-e in RG2TK+ tumors was not significantly different from control tumors. However, [{sup 18}F]1c and [{sup 18}F]1f had an average 1.6- and 1.7-fold higher uptake in RG2TK+ tumors than control RG2 tumors. Blood activity curves for [{sup 18}F]1c and [{sup 18}F]1f highlight rapid clearance of radioactivity in the blood. Dynamic small animal PET (A-PET) imaging studies of tumor-bearing mice with [{sup 18}F]1c and [{sup 18}F]1f showed higher initial uptake (3.5- and 1.4-fold, respectively) in RG2TK+ tumors than in control tumors, with continued washout of activity from both tumors over time. Conclusions: Biological evaluations suggest that [{sup 18}F]1c and [{sup 18}F]1f may have limited potential for imaging HSV1-tk gene expression due to fast washout of activity from the blood, thus significantly decreasing sensitivity and specificity of tracer accumulation in HSV1-tk-expressing tumors.

  8. Phycocyanin-Functionalized Selenium Nanoparticles Reverse Palmitic Acid-Induced Pancreatic β Cell Apoptosis by Enhancing Cellular Uptake and Blocking Reactive Oxygen Species (ROS)-Mediated Mitochondria Dysfunction.

    Science.gov (United States)

    Liu, Chang; Fu, Yuanting; Li, Chang-E; Chen, Tianfeng; Li, Xiaoling

    2017-06-07

    Accumulation of palmitic acid (PA) in human bodies could cause damage to pancreatic β cells and lead to chronic diseases by generation of reactive oxygen species (ROS). Therefore, it is of great significance to search for nutrition-available agents with antioxidant activity to protect pancreatic islet cells against PA-induced damage. Phycocyanin (PC) and selenium (Se) have been reported to have excellent antioxidant activity. In this study, PC-functionalized selenium nanoparticles (PC-SeNPs) were synthesized to investigate the in vitro protective effects on INS-1E rat insulinoma β cells against PA-induced cell death. A potent protective effect was achieved by regulation of particle size and PC content. Among three PC-SeNPs (165, 235, and 371 nm), PC-SeNPs-235 nm showed the highest cellular uptake and the best protective activities. For cell cycle analysis, PC-SeNPs showed a better protective effect on PA-induced INS-1E cell apoptosis than PC or SeNPs, and PC-SeNPs-235 nm exhibited the best effect. Further mechanistic studies demonstrated that PA induced overproduction of intracellular ROS, mitochondria fragmentation, activation of caspase-3, -8, and -9, and cleavage of PARP. However, pretreatment of the cells with PC-SeNPs effectively blocked these intracellular events, which suggests that PC-SeNPs could protect INS-1E cells against PA-induced cell apoptosis via attenuating oxidative stress and downstream signaling pathways. This finding provides a great promising nutritional approach for protection against diseases related to islet damage.

  9. Macrophage receptor with collagenous structure (MARCO) is a dynamic adhesive molecule that enhances uptake of carbon nanotubes by CHO-K1 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Seishiro, E-mail: seishiro@nies.go.jp [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Fujitani, Yuji; Furuyama, Akiko [Environmental Nanotoxicology Project, RCER, National Institute for Environmental Studies (Japan); Kanno, Sanae [Department of Legal Medicine, St. Marianna School of Medicine (Japan)

    2012-02-15

    The toxicity of carbon nanotubes (CNTs), a highly promising nanomaterial, is similar to that of asbestos because both types of particles have a fibrous shape and are biopersistent. Here, we investigated the characteristics of macrophage receptor with collagenous structure (MARCO), a membrane receptor expressed on macrophages that recognizes environmental or unopsonized particles, and we assessed whether and how MARCO was involved in cellular uptake of multi-walled CNTs (MWCNTs). MARCO-transfected Chinese hamster ovary (CHO-K1) cells took up polystyrene beads irrespective of the particle size (20 nm–1 μm). In the culture of MARCO-transfected CHO-K1 cells dendritic structures were observed on the bottom of culture dishes, and the edges of these dendritic structures were continually renewed as the cell body migrated along the dendritic structures. MWCNTs were first tethered to the dendritic structures and then taken up by the cell body. MWCNTs appeared to be taken up via membrane ruffling like macropinocytosis, rather than phagocytosis. The cytotoxic EC{sub 50} value of MWCNTs in MARCO-transfected CHO-K1 cells was calculated to be 6.1 μg/mL and transmission electron microscopic observation indicated that the toxicity of MWCNTs may be due to the incomplete inclusion of MWCNTs by the membrane structure. -- Highlights: ►Carbon nanotubes (CNTs) were tethered to MARCO in vitro. ►CNTs were taken up rapidly into the cell body via MARCO by membrane ruffling. ►The incomplete inclusion of CNTs by membranes caused cytotoxicity.

  10. Modifying Cationic Liposomes with Cholesteryl-PEG Prevents Their Aggregation in Human Urine and Enhances Cellular Uptake by Bladder Cancer Cells

    OpenAIRE

    Nakamura, Takashi; Noma, Yosuke; Sakurai, Yu; Harashima, Hideyoshi

    2017-01-01

    Intravesical drug delivery by cationic liposomes (Cat-LPs) represents a potent nanotechnology for enhancing therapeutic effects against bladder disorders. However, preventing the aggregation of Cat-LPs in urine poses a significant barrier. We report on an examination of the effect of modifying liposomes with polyethylene glycol (PEG) lipids to prevent Cat-LPs from aggregating in human urine. Although Cat-LPs underwent significant aggregation in human urine, introducing 5 mol% of PEG2k lipid o...

  11. Increased brain fatty acid uptake in metabolic syndrome

    DEFF Research Database (Denmark)

    Karmi, Anna; Iozzo, Patricia; Viljanen, Antti

    2010-01-01

    To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it.......To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it....

  12. Influence of concomitant infusion of thymidine and inosine on methotrexate activity in normal and P388-bearing mice

    NARCIS (Netherlands)

    Uitendaal, Martin P.; Schornagel, J.H.; Leyva, A.; Pinedo, H.M.

    1984-01-01

    Combinations of thymidine and inosine (ranging from 0 to 7.5 mg/hr) were co-administered during a 72-hr continuous i.v. infusion of 3 μg/hr methotrexate in normal and P388 solid tumor-bearing DBA/2 mice. Methotrexate alone was lethal to all normal mice. Inosine at 1.0–7.5 mg/hr could reverse

  13. Syntheses of pyrimidine acyclic nucleoside phosphonates as potent inhibitors of thymidine phosphorylase (PD-ECGF) from SD-lymphoma

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Votruba, Ivan; Holý, Antonín; Pohl, Radek

    2007-01-01

    Roč. 26, 8/9 (2007), s. 1025-1028 ISSN 1525-7770. [International Roundtable /17./. Bern, 03.09.2006-07.09.2006] R&D Projects: GA MŠk 1M0508 Grant - others: Descartes Prize(XE) HPAW-CT-2002-9001 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * pyrimidines * FPMP derivatives * fluorination Subject RIV: CC - Organic Chemistry Impact factor: 0.723, year: 2007

  14. Investigation on Cell Proliferation with a New Antibody against Thymidine Kinase 1

    Directory of Open Access Journals (Sweden)

    Naining Wang

    2001-01-01

    Full Text Available The cytosolic thymidine kinase 1 (TK1 is one of the enzymes involved in DNA replication. Based on biochemical studies, TK1 is activated at late G1 of cell cycle, and its activity correlates with the cell proliferation. We have developed a polyclonal anti‐TK1 antibody against a synthetic peptide from the C‐terminus of human TK1. Using this antibody, here we demonstrate the exclusive location of TK1 in the cytoplasm of cells. Cell cycle dependent TK1 expression was studied by simultaneous fluorescence staining for TK1 and bromodeoxyuridine, by using elutriated cells, and by quantitation of the amount TK1 in relation to the cellular DNA content. TK1, which was strongly expressed in the cells in S+G2 period, raised at late G1 and decreased during mitosis. The amount of TK1 increased three folds from late G1 to G2. TK1 positive cells were demonstrated in areas of proliferation activity of various normal and malignant tissues. The new anti‐TK1 antibody works in archival specimens and is a specific marker of cell proliferation.

  15. In Vitro Bypass of Thymidine Glycol by DNA Polymerase θ Forms Sequence-Dependent Frameshift Mutations.

    Science.gov (United States)

    Laverty, Daniel J; Greenberg, Marc M

    2017-12-26

    Unrepaired DNA lesions block replication and threaten genomic stability. Several specialized translesion polymerases, including polymerase θ (Pol θ), contribute to replicative bypass of these lesions. The role of Pol θ in double-strand break repair is well-understood, but its contribution to translesion synthesis is much less so. We describe the action of Pol θ on templates containing thymidine glycol (Tg), a major cytotoxic, oxidative DNA lesion that blocks DNA replication. Unrepaired Tg lesions are bypassed in human cells by specialized translesion polymerases by one of two distinct pathways: high-fidelity bypass by the combined action of Pol κ and Pol ζ or weakly mutagenic bypass by Pol θ. Here we report that in vitro bypass of Tg by Pol θ results in frameshift mutations (deletions) in a sequence-dependent fashion. Steady-state kinetic analysis indicated that one- and two-nucleotide deletions are formed 9- and 6-fold more efficiently, respectively, than correct, full-length bypass products. Sequencing of in vitro bypass products revealed that bypass preference decreased in the following order on a template where all three outcomes were possible: two-nucleotide deletion > correct bypass > one-nucleotide deletion. These results suggest that bypass of Tg by Pol θ results in mutations opposite the lesion, as well as frameshift mutations.

  16. Elimination of proliferating cells from CNS grafts using a Ki67 promoter-driven thymidine kinase.

    Science.gov (United States)

    Tieng, Vannary; Cherpin, Ophelie; Gutzwiller, Eveline; Zambon, Alexander C; Delgado, Christophe; Salmon, Patrick; Dubois-Dauphin, Michel; Krause, Karl-Heinz

    2016-01-01

    Pluripotent stem cell (PSC)-based cell therapy is an attractive concept for neurodegenerative diseases, but can lead to tumor formation. This is particularly relevant as proliferating neural precursors rather than postmitotic mature neurons need to be transplanted. Thus, safety mechanisms to eliminate proliferating cells are needed. Here, we propose a suicide gene approach, based on cell cycle-dependent promoter Ki67-driven expression of herpes simplex virus thymidine kinase (HSV-TK). We generated a PSC line expressing this construct and induced neural differentiation. In vitro, proliferating PSC and early neural precursor cells (NPC) were killed by exposure to ganciclovir. In vivo, transplantation of PSC led to tumor formation, which was prevented by early ganciclovir treatment. Transplanted NPC did not lead to tumor formation and their survival and neural maturation were not affected by ganciclovir. In conclusion, the cell cycle promoter-driven suicide gene approach described in this study allows killing of proliferating undifferentiated precursor cells without expression of the suicide gene in mature neurons. This approach could also be of use for other stem cell-based therapies where the final target consists of postmitotic cells.

  17. Elimination of proliferating cells from CNS grafts using a Ki67 promoter-driven thymidine kinase

    Directory of Open Access Journals (Sweden)

    Vannary Tieng

    2016-01-01

    Full Text Available Pluripotent stem cell (PSC-based cell therapy is an attractive concept for neurodegenerative diseases, but can lead to tumor formation. This is particularly relevant as proliferating neural precursors rather than postmitotic mature neurons need to be transplanted. Thus, safety mechanisms to eliminate proliferating cells are needed. Here, we propose a suicide gene approach, based on cell cycle-dependent promoter Ki67-driven expression of herpes simplex virus thymidine kinase (HSV-TK. We generated a PSC line expressing this construct and induced neural differentiation. In vitro, proliferating PSC and early neural precursor cells (NPC were killed by exposure to ganciclovir. In vivo, transplantation of PSC led to tumor formation, which was prevented by early ganciclovir treatment. Transplanted NPC did not lead to tumor formation and their survival and neural maturation were not affected by ganciclovir. In conclusion, the cell cycle promoter-driven suicide gene approach described in this study allows killing of proliferating undifferentiated precursor cells without expression of the suicide gene in mature neurons. This approach could also be of use for other stem cell-based therapies where the final target consists of postmitotic cells.

  18. Loss of arylformamidase with reduced thymidine kinase expression leads to impaired glucose tolerance

    Directory of Open Access Journals (Sweden)

    Alison J. Hugill

    2015-11-01

    Full Text Available Tryptophan metabolites have been linked in observational studies with type 2 diabetes, cognitive disorders, inflammation and immune system regulation. A rate-limiting enzyme in tryptophan conversion is arylformamidase (Afmid, and a double knockout of this gene and thymidine kinase (Tk has been reported to cause renal failure and abnormal immune system regulation. In order to further investigate possible links between abnormal tryptophan catabolism and diabetes and to examine the effect of single Afmid knockout, we have carried out metabolic phenotyping of an exon 2 Afmid gene knockout. These mice exhibit impaired glucose tolerance, although their insulin sensitivity is unchanged in comparison to wild-type animals. This phenotype results from a defect in glucose stimulated insulin secretion and these mice show reduced islet mass with age. No evidence of a renal phenotype was found, suggesting that this published phenotype resulted from loss of Tk expression in the double knockout. However, despite specifically removing only exon 2 of Afmid in our experiments we also observed some reduction of Tk expression, possibly due to a regulatory element in this region. In summary, our findings support a link between abnormal tryptophan metabolism and diabetes and highlight beta cell function for further mechanistic analysis.

  19. Identification and nucleotide sequence of the thymidine kinase gene of Shope fibroma virus

    Energy Technology Data Exchange (ETDEWEB)

    Upton, C.; McFadden, G.

    1986-12-01

    The thymidine kinase (TK) gene of Shope fibroma virus (SFV), a tumorigenic leporipoxvirus, was localized within the viral genome with degenerate oligonucleotide probes. These probes were constructed to two regions of high sequence conservation between the vaccinia virus TK gene and those of several known eucaryotic cellular TK genes, including human, mouse, hamster, and chicken TK genes. The oligonucleotide probes initially localized the SFV TK gene 50 kilobases (kb) from the right terminus of the 160-kb SFV genome within the 9.5-kb BamHI-HindIII fragment E. Fine-mapping analysis indicated that the TK Gene was within a 1.2-kb AvaI-HaeIII fragment, and DNA sequencing of this region revealed an open reading frame capable of encoding a polypeptide of 187 amino acids possessing considerable homology to the TK genes of the vaccinia, variola, and monkeypox orthopoxviruses and also to a variety of cellular TK genes. Homology matrix analysis and homology scores suggest that the SFV TK gene has diverged significantly from its counterpart members in the orthopoxvirus genus. Nevertheless, the presence of conserved upstream open reading frames on the 5' side of all of the poxvirus TK genes indicates a similarity of functional organization between the orthopoxviruses and leporipoxviruses. These data suggest a common ancestral origin for at least some of the unique internal regions of the leporipoxviruses and orthopoxviruses as exemplified by SFV and vaccinia virus, respectively.

  20. Thymidine Kinase Suicide Gene-mediated Ganciclovir Ablation of Autologous Gene-modified Rhesus Hematopoiesis

    Science.gov (United States)

    Barese, Cecilia N; Krouse, Allen E; Metzger, Mark E; King, Connor A; Traversari, Catia; Marini, Frank C; Donahue, Robert E; Dunbar, Cynthia E

    2012-01-01

    Despite the genotoxic complications encountered in clinical gene therapy trials for primary immunodeficiency diseases targeting hematopoietic cells with integrating vectors; this strategy holds promise for the cure of several monogenic blood, metabolic and neurodegenerative diseases. In this study, we asked whether the inclusion of a suicide gene in a standard retrovirus vector would allow elimination of vector-containing stem and progenitor cells and their progeny in vivo following transplantation, using our rhesus macaque transplantation model. Following stable engraftment with autologous CD34+ cells transduced with a retrovirus vector encoding a highly sensitive modified Herpes simplex virus thymidine kinase SR39, the administration of the antiviral prodrug ganciclovir (GCV) was effective in completely eliminating vector-containing cells in all hematopoietic lineages in vivo. The sustained absence of vector-containing cells over time, without additional GCV administration, suggests that the ablation of TkSR39 GCV-sensitive cells occurred in the most primitive hematopoietic long-term repopulating stem or progenitor cell compartment. These results are a proof-of-concept that the inclusion of a suicide gene in integrating vectors, in addition to a therapeutic gene, can provide a mechanism for later elimination of vector-containing cells, thereby increasing the safety of gene transfer. PMID:22910293

  1. The effect of chlorination of nucleotide bases on the conformational properties of thymidine monophosphate

    Directory of Open Access Journals (Sweden)

    T. M. Mukhina

    2015-04-01

    Full Text Available Recent studies on Escherichia coli bacteria cultivation, in which DNA thymine was replaced with 5-chlorouracil have refreshed the problem of understanding the changes to physical properties of DNA monomers resultant from chemical modifications. These studies have shown that the replacement did not affect the normal activities and division of the bacteria, but has significantly reduced its life span. In this paper a comparative analysis was carried out by the methods of computational experiment of a set of 687 possible conformers of natural monomeric DNA unit (2′-deoxyribonucleotide thymidine monophosphate and 660 conformers of 5-chloro-2′-deoxyuridine monophosphate – a similar molecules in which the natural nitrogenous base thymine is substituted with 5-chlorouracil. Structures of stable conformers of the modified deoxyribonucleotide have been obtained and physical factors, which determine their variation from the conformers of the unmodified molecule have been analyzed. A comparative analysis of the elastic properties of conformers­ of investigated molecules and non-covalent interactions present in them was conducted. The results can be used for planning experiments on synthesis of artificial DNA suitable for incorporation into living organisms.

  2. New Variants of Tomato Thymidine Kinase 1 Selected for Increased Sensitivity of E. coli KY895 towards Azidothymidine

    Directory of Open Access Journals (Sweden)

    Louise Slot Christiansen

    2015-06-01

    Full Text Available Nucleoside analogues (NA are prodrugs that are phosphorylated by deoxyribonucleoside kinases (dNKs as the first step towards a compound toxic to the cell. During the last 20 years, research around dNKs has gone into new organisms other than mammals and viruses. Newly discovered dNKs have been tested as enzymes for suicide gene therapy. The tomato thymidine kinase 1 (ToTK1 is a dNK that has been selected for its in vitro kinetic properties and then successfully been tested in vivo for the treatment of malignant glioma. We present the selection of two improved variants of ToTK1 generated by random protein engineering for suicide gene therapy with the NA azidothymidine (AZT.We describe their selection, recombinant production and a subsequent kinetic and biochemical characterization. Their improved performance in killing of E. coli KY895 is accompanied by an increase in specificity for the NA AZT over the natural substrate thymidine as well as a decrease in inhibition by dTTP, the end product of the nucleoside salvage pathway for thymidine. The understanding of the enzymatic properties improving the variants efficacy is instrumental to further develop dNKs for use in suicide gene therapy.

  3. Bacterial production determined by [3H]thymidine incorporation in field rhizospheres as evaluated by comparison to rhizodeposition

    DEFF Research Database (Denmark)

    Christensen, Henrik; Rønn, Regin; Ekelund, Flemming

    1995-01-01

    .2–15 × 104 cells g-1 soil) as well as elevated thymidine incorporation (9.7–12 pmol g-1 soil) in rhizosphere soil compared to bulk soil. Rhizodeposition, as determined by several pulse labellings with 14CO2, was estimated to be 412 µg C g-1 dry wt soil in the 0–15 cm layer. Bacterial production......, as determined by incorporation of 3H-labelled thymidine converted to bacterial C, revealed a plant-induced formation of 1348 µg bacterial C g-1 soil in the 0–15 cm layer. This is probably the first estimate for bacterial production based on thymidine incorporation which has been compared to an estimate of C......In a sandy loam soil cropped to barley bacterial production in the rhizosphere was compared to the results of a parallel investigation on rhizodeposition. Bacterial production was stimulated in the rhizosphere as revealed by an increased biomass of bacteria (643–883 µg C g-1 soil) and protozoa (7...

  4. New Variants of Tomato Thymidine Kinase 1 Selected for Increased Sensitivity of E. coli KY895 towards Azidothymidine

    Energy Technology Data Exchange (ETDEWEB)

    Slot Christiansen, Louise [Department of Biology, Lund University, Lund 22362 (Sweden); Lund Protein Production Platform, Lund University, Lund 22362 (Sweden); Egeblad, Louise [Lund Protein Production Platform, Lund University, Lund 22362 (Sweden); Munch-Petersen, Birgitte [Department of Science, Systems and Models, Roskilde University, Roskilde 4000 (Denmark); Piškur, Jure [Department of Biology, Lund University, Lund 22362 (Sweden); Knecht, Wolfgang, E-mail: Louise.Slot_Christiansen@biol.lu.se [Department of Biology, Lund University, Lund 22362 (Sweden); Lund Protein Production Platform, Lund University, Lund 22362 (Sweden)

    2015-06-08

    Nucleoside analogues (NA) are prodrugs that are phosphorylated by deoxyribonucleoside kinases (dNKs) as the first step towards a compound toxic to the cell. During the last 20 years, research around dNKs has gone into new organisms other than mammals and viruses. Newly discovered dNKs have been tested as enzymes for suicide gene therapy. The tomato thymidine kinase 1 (ToTK1) is a dNK that has been selected for its in vitro kinetic properties and then successfully been tested in vivo for the treatment of malignant glioma. We present the selection of two improved variants of ToTK1 generated by random protein engineering for suicide gene therapy with the NA azidothymidine (AZT). We describe their selection, recombinant production and a subsequent kinetic and biochemical characterization. Their improved performance in killing of E. coli KY895 is accompanied by an increase in specificity for the NA AZT over the natural substrate thymidine as well as a decrease in inhibition by dTTP, the end product of the nucleoside salvage pathway for thymidine. The understanding of the enzymatic properties improving the variants efficacy is instrumental to further develop dNKs for use in suicide gene therapy.

  5. A designed equine herpes thymidine kinase (EHV4 TK) variant improves ganciclovir-induced cell-killing.

    Science.gov (United States)

    McSorley, Theresa; Ort, Stephan; Monnerjahn, Christian; Konrad, Manfred

    2014-02-01

    The limitations of the ganciclovir (GCV)/herpes simplex virus thymidine kinase (HSV1 TK: EC 2.7.1.21) system as a suicide gene therapy approach have been extensively studied over the years. In our study, we focused on improving the cytotoxic profile of the GCV/equine herpes virus-4 thymidine kinase (EHV4 TK: EC 2.7.1.21) system. Our approach involved the structure-guided mutagenesis of EHV4 TK in order to switch its ability to preferentially phosphorylate the natural substrate deoxythymidine (dT) to that of GCV. We performed steady-state kinetic analysis, genetic complementation in a thymidine kinase-deficient Escherichia coli strain, isothermal titration calorimetry, and analysis of GCV-induced cell killing through generation of HEK 293 stable cell-lines expressing EHV4 TK mutants and wild-type EHV4 TK. We found that the EHV4 TK S144H-GFP mutant preferentially phosphorylates GCV and confers increased GCV-induced cytotoxicity compared to wild-type EHV4 TK. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Bacterium-based heavy metal biosorbents: enhanced uptake of cadmium by E. coli expressing a metallothionein fused to beta-galactosidase.

    Science.gov (United States)

    Yoshida, N; Kato, T; Yoshida, T; Ogawa, K; Yamashita, M; Murooka, Y

    2002-03-01

    We investigated the potential utility of a recombinant E. coli that expresses the human metallothionein II gene as a fusion protein with beta-galactosidase as a heavy metal biosorbent. E. coli cells expressing the metallothionein fusion demonstrated enhanced binding of Cd2+ compared to cells that lack the metallothionein. It was shown that the metallothionein fusion was capable of efficiently removing Cd2+ from solutions. Approximately 40% of the Cd2+ accumulated by the recombinant cells free in suspension was associated with the outer cell membrane, and 60% of that was present in the cytoplasm.

  7. The Soybean Basic Helix-Loop-Helix Transcription Factor ORG3-Like Enhances Cadmium Tolerance via Increased Iron and Reduced Cadmium Uptake and Transport from Roots to Shoots

    Directory of Open Access Journals (Sweden)

    Zhaolong Xu

    2017-06-01

    Full Text Available Cadmium (Cd is one of the most dangerous heavy metal pollutants in the environment and is toxic to animal and plant cells. On the other hand, iron (Fe is an essential element for plant growth and development. The chlorosis of plant leaves under cadmium stress is similar to the typical symptom of iron deficiency. Recently, several Arabidopsis basic/helix-loop-helix (bHLH transcription factors have been identified that are involved in the interactions between Cd and Fe. In the present study, over-expression the ORG3-like gene GmORG3, a bHLH transcription factor OBP3-responsive gene (ORG, enhanced Cd tolerance and stabilized Fe homeostasis. The domain analysis of GmORG3 showed that the protein contains a conserved 61-residue bHLH domain belonging to subfamily II. Moreover, subcellular localization experiments showed that GmORG3 is a nucleoprotein. GmORG3 was transcribed only in soybean roots and was significantly induced by external Cd stress in soybean plants. Heterologous expression of GmORG3 enhanced Cd tolerance in yeast. Furthermore, the overexpression of GmORG3 in soybean mosaic seedlings using a hairy root system showed that overexpressing plants increased the translocation ratio of Fe but reduced Cd translocation from the roots to shoots. In addition, the ectopic expression of GmORG3 in tobacco reduced phytotoxic effects induced by Cd stress and Fe deficiency, including the blockage of root elongation and decreased chlorophyll content. By integrating all these results, we found that GmORG3 plays an important role in response to Cd stress. The results provide new insights into the molecular mechanisms of Cd tolerance in soybean.

  8. Thyroid Scan and Uptake

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ...

  9. Thyroid Scan and Uptake

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    Full Text Available ... A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ... a patient’s immediate response to therapeutic interventions. Nuclear ... medical tests that help physicians diagnose and evaluate medical conditions. ...

  10. Thyroid Scan and Uptake

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    Full Text Available ... 24 hours later. Often, two separate uptake measurements are obtained at different times. For example, you may have uptake measurements at ... of exposing the fetus to radiation. These tests are also not recommended for ... medicine procedures can be time consuming. It can take several hours to days ...

  11. Effects of ozone inhalation on polyamine metabolism and tritiated thymidine incorporation into DNA of rat lungs

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, N.M.; Ellingson, A.S.; Tierney, D.F.; Mustafa, M.G. (Univ. of California, Los Angeles (USA))

    1990-01-01

    We examined the effects of low-level ozone (O3) inhalation on polyamine metabolism and tritiated thymidine (3H-TdR) incorporation into DNA in rat lungs. We have also compared the activities of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis, and glucose-6-phosphate dehydrogenase (G6PD), the key enzyme of the pentose phosphate cycle and a typical marker of oxidant injury, to assess whether ODC can serve as a sensitive marker of O3 effects on the lung. We exposed 90-day-old male specific-pathogen-free Sprague-Dawley rats to either 0.45 +/- 0.05 ppm (882 +/- 98 micrograms/m3) O3 or filtered room air continuously for 3 days. After exposure, the rats were terminated and the lungs examined for enzyme activities, polyamine contents, DNA content, and 3H-TdR incorporation. We found that in exposed rats, the enzyme activities were significantly increased (p less than 0.05) relative to air controls. G6PD, 25%, ODC, 147%, and S-adenosylmethionine decarboxylase (AdoMet DC), 86%. Polyamine contents were also affected by O3; putrescine increased 80%, p less than 0.05, spermidine did not change, and spermine decreased 23%, p less than 0.05. 3H-TdR incorporation into DNA was significantly elevated, 155%, p less than 0.001, after O3 exposure while total lung DNA content remained unchanged. The concomitant and large increase in ODC activity (reflecting polyamine metabolism) and DNA labeling (reflecting DNA synthesis and/or repair), indicates a strong correlation between the two and suggests that polyamine metabolism may play an important role in the accelerated cell proliferation associated with O3 injury. Moreover, the greater increase in lung ODC activity compared to other enzymes offers a sensitive marker of the lung response to inhaled O3.

  12. [The thymidine phosphorylase as the platelet-derived endothelial cell growth factor of endometrial cancer].

    Science.gov (United States)

    Kubiak, Robert; Miszczak-Zaborska, Elzbieta; Smolarek, Monika; Wójcik-Krowiranda, Katarzyna; Bartkowiak, Jacek

    2009-08-01

    The aim of the study was to assess the correlation between the activity of thymidine phosphorylase (TP) and the platelet derived-endothelial cell growth factor (PD-ECGF) expression in endometrial carcinoma. The study group consisted of 40 tissue samples taken from patients with endometrial carcinoma, who underwent surgery in First Clinic of Gynecology and Oncologic Gynecology of Medical University in Lodz. The control tissue samples were taken from patients who were operated on for non-oncologic reason. The activity of TP was measured by the spectrophotometric method in the cytosol of tumor cells, and the immunohistochemical staining of PD-ECGF was performed in the same tumors. The results of TP activity were compared with the microvessel density (MD) assessed by immunohistochemical analysis and with clinico-pathological features like tumor grade and FIGO stage. A positive correlation between the enzyme activity and expression of TP/PD-ECGF protein was found. Moreover a significantly higher TP activity was confirmed in malignant tumors from endometrial cancer patients when compared to the controls. A positive correlation between the enzyme activity and MD was also stated, but there was no connection to the grade of tumors and FIGO stage. Since the TP activity proved to be related to PD-ECGF expression and angiogenesis, we can state that TP seems to be an active form of PD-ECGF growth factor in endometrial carcinoma. This is in agreement with the results of many publications on other malignancies. The proper modulation of this activity may be useful in adjuvant therapies.

  13. Plant thymidine kinase 1: a novel efficient suicide gene for malignant glioma therapy.

    Science.gov (United States)

    Khan, Zahidul; Knecht, Wolfgang; Willer, Mette; Rozpedowska, Elzbieta; Kristoffersen, Peter; Clausen, Anders Ranegaard; Munch-Petersen, Birgitte; Almqvist, Per M; Gojkovic, Zoran; Piskur, Jure; Ekström, Tomas J

    2010-06-01

    The prognosis for malignant gliomas remains poor, and new treatments are urgently needed. Targeted suicide gene therapy exploits the enzymatic conversion of a prodrug, such as a nucleoside analog, into a cytotoxic compound. Although this therapeutic strategy has been considered a promising regimen for central nervous system (CNS) tumors, several obstacles have been encountered such as inefficient gene transfer to the tumor cells, limited prodrug penetration into the CNS, and inefficient enzymatic activity of the suicide gene. We report here the cloning and successful application of a novel thymidine kinase 1 (TK1) from the tomato plant, with favorable characteristics in vitro and in vivo. This enzyme (toTK1) is highly specific for the nucleoside analog prodrug zidovudine (azidothymidine, AZT), which is known to penetrate the blood-brain barrier. An important feature of toTK1 is that it efficiently phosphorylates its substrate AZT not only to AZT monophosphate, but also to AZT diphosphate, with excellent kinetics. The efficiency of the toTK1/AZT system was confirmed when toTK1-transduced human glioblastoma (GBM) cells displayed a 500-fold increased sensitivity to AZT compared with wild-type cells. In addition, when neural progenitor cells were used as delivery vectors for toTK1 in intracranial GBM xenografts in nude rats, substantial attenuation of tumor growth was achieved in animals exposed to AZT, and survival of the animals was significantly improved compared with controls. The novel toTK1/AZT suicide gene therapy system in combination with stem cell-mediated gene delivery promises new treatment of malignant gliomas.

  14. Identification of Fhit as a post-transcriptional effector of Thymidine Kinase 1 expression.

    Science.gov (United States)

    Kiss, Daniel L; Waters, Catherine E; Ouda, Iman M; Saldivar, Joshua C; Karras, Jenna R; Amin, Zaynab A; Mahrous, Seham; Druck, Teresa; Bundschuh, Ralf A; Schoenberg, Daniel R; Huebner, Kay

    2017-03-01

    FHIT is a genome caretaker gene that is silenced in >50% of cancers. Loss of Fhit protein expression promotes accumulation of DNA damage, affects apoptosis and epithelial-mesenchymal transition, though molecular mechanisms underlying these alterations have not been fully elucidated. Initiation of genome instability directly follows Fhit loss and the associated reduced Thymidine Kinase 1 (TK1) protein expression. The effects on TK1 of Fhit knockdown and Fhit induction in the current study confirmed the role of Fhit in regulating TK1 expression. Changes in Fhit expression did not impact TK1 protein turnover or transcription from the TK1 promoter, nor steady-state levels of TK1 mRNA or turnover. Polysome profile analysis showed that up-regulated Fhit expression resulted in decreased TK1 RNA in non-translating messenger ribonucleoproteins and increased ribosome density on TK1 mRNA. Fhit does not bind RNA but its expression increased luciferase expression from a transgene bearing the TK1 5'-UTR. Fhit has been reported to act as a scavenger decapping enzyme, and a similar result with a mutant (H96) that binds but does not cleave nucleoside 5',5'-triphosphates suggests the impact on TK1 translation is due to its ability to modulate the intracellular level of cap-like molecules. Consistent with this, cells expressing Fhit mutants with reduced activity toward cap-like dinucleotides exhibit DNA damage resulting from TK1 deficiency, whereas cells expressing wild-type Fhit or the H96N mutant do not. The results have implications for the mechanism by which Fhit regulates TK1 mRNA, and more broadly, for its modulation of multiple functions as tumor suppressor/genome caretaker. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Mitochondria-acting hexokinase II peptides carried by short-length carbon nanotubes with increased cellular uptake, endosomal evasion, and enhanced bioactivity against cancer cells

    Science.gov (United States)

    Yoong, Sia Lee; Lau, Wei Liang; Liu, Ang Yu; Prendergast, D'arcy; Ho, Han Kiat; Yu, Victor Chun Kong; Lee, Chengkuo; Ang, Wee Han; Pastorin, Giorgia

    2015-08-01

    Type II hexokinase (HKII) has emerged as a viable therapeutic target due to its involvement in metabolic reprogramming and also apoptosis prevention. The peptide derived from the fifteen amino acid sequence in the HKII N-terminal region [HKII(pep)] can compete with endogenous proteins for binding on mitochondria and trigger apoptosis. However, this peptide is not cell-permeable. In this study, multi-walled carbon nanotubes (MWCNTs) were used to effectively deliver HKII(pep) across cellular barriers without compromising their bioactivity. The peptide was conjugated on either oxidized MWCNTs or 2,2'-(ethylenedioxy)bis(ethylamine)-functionalized MWCNTs, yielding MWCNT-HKII(pep) and MWCNT-TEG-HKII(pep), respectively. Both conjugates were shown to be internalized by breast cancer MCF-7 cells using confocal microscopy. Moreover, these nanoconjugates seemed to have escaped from endosomes and be in the vicinity of mitochondria. The WST-1 cytotoxicity assay conducted on MCF-7 and colon carcinoma HCT116 cells revealed that MWCNT-peptide conjugates were significantly more effective in curbing cancer cell growth compared to a commercially available cell permeable HKII fusion peptide. In addition, both nanoconjugates displayed an enhanced ability in eliciting apoptosis and depleting the ATP level in HCT116 cells compared to the mere HKII peptide. Importantly, hexokinase II release from mitochondria was demonstrated in MWCNT-HKII(pep) and MWCNT-TEG-HKII(pep) treated cells, highlighting that the structure and bioactivity of HKII(pep) were not compromised after covalent conjugation to MWCNTs.Type II hexokinase (HKII) has emerged as a viable therapeutic target due to its involvement in metabolic reprogramming and also apoptosis prevention. The peptide derived from the fifteen amino acid sequence in the HKII N-terminal region [HKII(pep)] can compete with endogenous proteins for binding on mitochondria and trigger apoptosis. However, this peptide is not cell-permeable. In this study

  16. Varying cognitive targets and response rates to enhance the question-behaviour effect: An 8-arm Randomized Controlled Trial on influenza vaccination uptake.

    Science.gov (United States)

    Conner, Mark; Sandberg, Tracy; Nekitsing, Chandani; Hutter, Russell; Wood, Chantelle; Jackson, Cath; Godin, Gaston; Sheeran, Paschal

    2017-05-01

    The question-behaviour effect (QBE) refers to the finding that survey questions about a behaviour can change that behaviour. However, little research has tested how the QBE can be maximized in behavioural medicine settings. The present research tested manipulations of cognitive targets (questions about anticipated regret or beneficence) and survey return rates (presence vs. absence of a sticky note requesting completion of the questionnaire) on the magnitude of the QBE for influenza vaccination in older adults. Participants (N = 13,803) were recruited from general practice and randomly allocated to one of eight conditions: control 1 (no questionnaire); control 2 (demographics questionnaire); intention and attitude questionnaire (with or without a sticky note); intention and attitude plus anticipated regret questionnaire (with or without a sticky note); intention and attitude plus beneficence questionnaire (with or without a sticky note). Objective records of subsequent influenza vaccination from general practice records formed the dependent variable. Intention-to-treat analyses indicated that receiving an influenza vaccination questionnaire significantly increased vaccination rates compared to the no questionnaire, OR = 1.17, 95% CI = 1.01, 1.36 and combined control conditions, OR = 1.13, 95% CI = 1.01, 1.25. Including the sticky note significantly increased questionnaire return rates, OR = 1.25, 95% CI = 1.04, 1.50. However, there were no differences in vaccination rates between questionnaires containing different cognitive targets, a sticky note or not, and no interactions. There were no significant differences in the per-protocol analyses, i.e. among respondents who completed and returned the questionnaires. The QBE is a simple, low-cost intervention to increase influenza vaccination rates. Increasing questionnaire return rates or asking anticipated regret or beneficence questions in addition to intention and attitude questions did not enhance the

  17. l-Arginine Uptake by Cationic Amino Acid Transporter Promotes Intra-Macrophage Survival of Leishmania donovani by Enhancing Arginase-Mediated Polyamine Synthesis

    Directory of Open Access Journals (Sweden)

    Abhishek Mandal

    2017-07-01

    Full Text Available The survival of intracellular protozoan parasite, Leishmania donovani, the causative agent of Indian visceral leishmaniasis (VL, depends on the activation status of macrophages. l-Arginine, a semi-essential amino acid plays a crucial regulatory role for activation of macrophages. However, the role of l-arginine transport in VL still remains elusive. In this study, we demonstrated that intra-macrophage survival of L. donovani depends on the availability of extracellular l-arginine. Infection of THP-1-derived macrophage/human monocyte-derived macrophage (hMDM with Leishmania, resulted in upregulation of l-arginine transport. While investigating the involvement of the transporters, we observed that Leishmania survival was greatly impaired when the transporters were blocked either using inhibitor or siRNA-mediated downregulation. CAT-2 was found to be the main isoform associated with l-arginine transport in L. donovani-infected macrophages. l-arginine availability and its transport regulated the host arginase in Leishmania infection. Arginase and inducible nitric oxide synthase (iNOS expression were reciprocally regulated when assayed using specific inhibitors and siRNA-mediated downregulation. Interestingly, induction of iNOS expression and nitric oxide production were observed in case of inhibition of arginase in infected macrophages. Furthermore, inhibition of l-arginine transport as well as arginase resulted in decreased polyamine production, limiting parasite survival inside macrophages. l-arginine availability and transport regulated Th1/Th2 cytokine levels in case of Leishmania infection. Upregulation of l-arginine transport, induction of host arginase, and enhanced polyamine production were correlated with increased level of IL-10 and decreased level of IL-12 and TNF-α in L. donovani-infected macrophages. Our findings provide clear evidence for targeting the metabolism of l-arginine and l-arginine-metabolizing enzymes as an important

  18. l-Arginine Uptake by Cationic Amino Acid Transporter Promotes Intra-Macrophage Survival of Leishmania donovani by Enhancing Arginase-Mediated Polyamine Synthesis.

    Science.gov (United States)

    Mandal, Abhishek; Das, Sushmita; Kumar, Ajay; Roy, Saptarshi; Verma, Sudha; Ghosh, Ayan Kumar; Singh, Ruby; Abhishek, Kumar; Saini, Savita; Sardar, Abul Hasan; Purkait, Bidyut; Kumar, Ashish; Mandal, Chitra; Das, Pradeep

    2017-01-01

    The survival of intracellular protozoan parasite, Leishmania donovani, the causative agent of Indian visceral leishmaniasis (VL), depends on the activation status of macrophages. l-Arginine, a semi-essential amino acid plays a crucial regulatory role for activation of macrophages. However, the role of l-arginine transport in VL still remains elusive. In this study, we demonstrated that intra-macrophage survival of L. donovani depends on the availability of extracellular l-arginine. Infection of THP-1-derived macrophage/human monocyte-derived macrophage (hMDM) with Leishmania, resulted in upregulation of l-arginine transport. While investigating the involvement of the transporters, we observed that Leishmania survival was greatly impaired when the transporters were blocked either using inhibitor or siRNA-mediated downregulation. CAT-2 was found to be the main isoform associated with l-arginine transport in L. donovani-infected macrophages. l-arginine availability and its transport regulated the host arginase in Leishmania infection. Arginase and inducible nitric oxide synthase (iNOS) expression were reciprocally regulated when assayed using specific inhibitors and siRNA-mediated downregulation. Interestingly, induction of iNOS expression and nitric oxide production were observed in case of inhibition of arginase in infected macrophages. Furthermore, inhibition of l-arginine transport as well as arginase resulted in decreased polyamine production, limiting parasite survival inside macrophages. l-arginine availability and transport regulated Th1/Th2 cytokine levels in case of Leishmania infection. Upregulation of l-arginine transport, induction of host arginase, and enhanced polyamine production were correlated with increased level of IL-10 and decreased level of IL-12 and TNF-α in L. donovani-infected macrophages. Our findings provide clear evidence for targeting the metabolism of l-arginine and l-arginine-metabolizing enzymes as an important therapeutic and

  19. The effect of adriamycin on dentinogenesis and 3H-thymidine incorporation into the enamel organ of the rat incisor.

    Science.gov (United States)

    Karim, A C

    1990-01-01

    The effect of adriamycin (5 mg/kg) on 3H-thymidine incorporation and on dentin formation was studied in rat incisors. Male Sprague Dawley rats received an intravenous injection of adriamycin. Some of these also received a subcutaneous injection of 3H-thymidine at a dose of 2 mCi/kg one day later. One group of control animals received an intravenous injection of a volume of physiological saline equal to that of the adriamycin dose. Another group received physiological saline, and one hour later was given an additional injection of 3H-thymidine at a similar dose as above. All the animals were killed by perfusion with 2.5% phosphate buffered glutaraldehyde 1 h, 1 d, 4 d, 8 d, 16 d, 28 d, and 32 d after 3H-thymidine treatment. Light microscopy revealed irregular dentin deposits between the mantle and circumpulpal layer of the labial dentin at 16 d. Within these deposits were trapped cells. The latter, through radioautographic labelling, appeared to be cells from the odontoblast layer. Also, the labelling pattern of the enamel organ in both the control and experimental groups indicated that the eruption rate of the tooth was not affected. Serial sectioning and examination of the lingual portion of the incisors at 28 d revealed a lack of dentin formation and a failure in the closure of the apical foramen. Electron microscopic observations showed an irregular and random arrangement of collagen fibers within the deposits of irregular dentin, and the presence of twisted odontoblastic processes. Examination of the lingual surface showed the presence of fibroblasts and collagen fibers bridging the gap that resulted from the failure in dentin formation. These cells, which were similar to periodontal ligament cells, appeared to have arisen from that area. These results indicate that adriamycin has no effect on tooth eruption, but has a reversible effect on the function of secretory odontoblasts, which manifested itself as a periodic deposition of irregular dentin on the labial

  20. Characterization of genome-reduced Bacillus subtilis strains and their application for the production of guanosine and thymidine.

    Science.gov (United States)

    Li, Yang; Zhu, Xujun; Zhang, Xueyu; Fu, Jing; Wang, Zhiwen; Chen, Tao; Zhao, Xueming

    2016-06-03

    Genome streamlining has emerged as an effective strategy to boost the production efficiency of bio-based products. Many efforts have been made to construct desirable chassis cells by reducing the genome size of microbes. It has been reported that the genome-reduced Bacillus subtilis strain MBG874 showed clear advantages for the production of several heterologous enzymes including alkaline cellulase and protease. In addition to enzymes, B. subtilis is also used for the production of chemicals. To our best knowledge, it is still unknown whether genome reduction could be used to optimize the production of chemicals such as nucleoside products. In this study, we constructed a series of genome-reduced strains by deleting non-essential regions in the chromosome of B. subtilis 168. These strains with genome reductions ranging in size from 581.9 to 814.4 kb displayed markedly decreased growth rates, sporulation ratios, transformation efficiencies and maintenance coefficients, as well as increased cell yields. We re-engineered the genome-reduced strains to produce guanosine and thymidine, respectively. The strain BSK814G2, in which purA was knocked out, and prs, purF and guaB were co-overexpressed, produced 115.2 mg/L of guanosine, which was 4.4-fold higher compared to the control strain constructed by introducing the same gene modifications into the parental strain. We also constructed a thymidine producer by deleting the tdk gene and overexpressing the prs, ushA, thyA, dut, and ndk genes from Escherichia coli in strain BSK756, and the resulting strain BSK756T3 accumulated 151.2 mg/L thymidine, showing a 5.2-fold increase compared to the corresponding control strain. Genome-scale genetic manipulation has a variety of effects on the physiological characteristics and cell metabolism of B. subtilis. By introducing specific gene modifications related to guanosine and thymidine accumulation, respectively, we demonstrated that genome-reduced strains had greatly improved

  1. Is thymidine glycol containing DNA a substrate of E. coli DNA mismatch repair system?

    Science.gov (United States)

    Perevozchikova, Svetlana A; Trikin, Roman M; Heinze, Roger J; Romanova, Elena A; Oretskaya, Tatiana S; Friedhoff, Peter; Kubareva, Elena A

    2014-01-01

    The DNA mismatch repair (MMR) system plays a crucial role in the prevention of replication errors and in the correction of some oxidative damages of DNA bases. In the present work the most abundant oxidized pyrimidine lesion, 5,6-dihydro-5,6-dihydroxythymidine (thymidine glycol, Tg) was tested for being recognized and processed by the E. coli MMR system, namely complex of MutS, MutL and MutH proteins. In a partially reconstituted MMR system with MutS-MutL-MutH proteins, G/Tg and A/Tg containing plasmids failed to provoke the incision of DNA. Tg residue in the 30-mer DNA duplex destabilized double helix due to stacking disruption with neighboring bases. However, such local structural changes are not important for E. coli MMR system to recognize this lesion. A lack of repair of Tg containing DNA could be due to a failure of MutS (a first acting protein of MMR system) to interact with modified DNA in a proper way. It was shown that Tg in DNA does not affect on ATPase activity of MutS. On the other hand, MutS binding affinities to DNA containing Tg in G/Tg and A/Tg pairs are lower than to DNA with a G/T mismatch and similar to canonical DNA. Peculiarities of MutS interaction with DNA was monitored by Förster resonance energy transfer (FRET) and fluorescence anisotropy. Binding of MutS to Tg containing DNAs did not result in the formation of characteristic DNA kink. Nevertheless, MutS homodimer orientation on Tg-DNA is similar to that in the case of G/T-DNA. In contrast to G/T-DNA, neither G/Tg- nor A/Tg-DNA was able to stimulate ADP release from MutS better than canonical DNA. Thus, Tg residue in DNA is unlikely to be recognized or processed by the E. coli MMR system. Probably, the MutS transformation to active "sliding clamp" conformation on Tg-DNA is problematic.

  2. Thyroid Scan and Uptake

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    Full Text Available ... for the imaging to begin, you will lie down on a moveable examination table with your head ... each thyroid uptake is five minutes or less. top of page What will I experience during and ...

  3. Thyroid Scan and Uptake

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    Full Text Available ... for several hours before your exam because eating can affect the accuracy of the uptake measurement. Jewelry ... small hand-held device resembling a microphone that can detect and measure the amount of the radiotracer ...

  4. Thyroid Scan and Uptake

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    Full Text Available ... is taken by mouth, in either liquid or capsule form, it is typically swallowed up to 24 ... I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin ...

  5. Thyroid Scan and Uptake

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    Full Text Available ... scan and uptake uses small amounts of radioactive materials called radiotracers, a special camera and a computer ... last two months that used iodine-based contrast material. Your doctor will instruct you on how to ...

  6. Thyroid Scan and Uptake

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    Full Text Available ... Actual scanning time for each thyroid uptake is five minutes or less. top of page What will ... diagnostic procedures have been used for more than five decades, and there are no known long-term ...

  7. Thyroid Scan and Uptake

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    Full Text Available ... A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is ... thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that uses ...

  8. Thyroid Scan and Uptake

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    Full Text Available ... several hours before your exam because eating can affect the accuracy of the uptake measurement. Jewelry and ... often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information ...

  9. Thyroid Scan and Uptake

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    Full Text Available ... RAIU) is also known as a thyroid uptake. It is a measurement of thyroid function, but does ... they offer the potential to identify disease in its earliest stages as well as a patient’s immediate ...

  10. Thyroid Scan and Uptake

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    Full Text Available ... Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential ... or imaging device that produces pictures and provides molecular information. The thyroid scan and thyroid uptake provide ...

  11. Thyroid Scan and Uptake

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    Full Text Available ... information about your thyroid’s size, shape, position and function that is often unattainable using other imaging procedures. ... thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. Nuclear medicine is ...

  12. Thyroid Scan and Uptake

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    Full Text Available ... scan and thyroid uptake provide information about the structure and function of the thyroid. The thyroid is ... computer, create pictures offering details on both the structure and function of organs and tissues in your ...

  13. Thyroid Scan and Uptake

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    Full Text Available ... procedures within the last two months that used iodine-based contrast material. Your doctor will instruct you ... a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a ...

  14. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... eat for several hours before your exam because eating can affect the accuracy of the uptake measurement. ... often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information ...

  15. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... When radiotracer is taken by mouth, in either liquid or capsule form, it is typically swallowed up ... radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake ...

  16. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... nuclear medicine include the gamma camera and single-photon emission-computed tomography (SPECT). The gamma camera, also ... to 24 hours later. Often, two separate uptake measurements are obtained at different times. For example, you ...

  17. Enhanced

    Directory of Open Access Journals (Sweden)

    Martin I. Bayala

    2014-06-01

    Full Text Available Land Surface Temperature (LST is a key parameter in the energy balance model. However, the spatial resolution of the retrieved LST from sensors with high temporal resolution is not accurate enough to be used in local-scale studies. To explore the LST–Normalised Difference Vegetation Index relationship potential and obtain thermal images with high spatial resolution, six enhanced image sharpening techniques were assessed: the disaggregation procedure for radiometric surface temperatures (TsHARP, the Dry Edge Quadratic Function, the Difference of Edges (Ts∗DL and three models supported by the relationship of surface temperature and water stress of vegetation (Normalised Difference Water Index, Normalised Difference Infrared Index and Soil wetness index. Energy Balance Station data and in situ measurements were used to validate the enhanced LST images over a mixed agricultural landscape in the sub-humid Pampean Region of Argentina (PRA, during 2006–2010. Landsat Thematic Mapper (TM and Moderate Resolution Imaging Spectroradiometer (EOS-MODIS thermal datasets were assessed for different spatial resolutions (e.g., 960, 720 and 240 m and the performances were compared with global and local TsHARP procedures. Results suggest that the Ts∗DL technique is the most adequate for simulating LST to high spatial resolution over the heterogeneous landscape of a sub-humid region, showing an average root mean square error of less than 1 K.

  18. Methodology and problems of protein-ligand docking: case study of dihydroorotate dehydrogenase, thymidine kinase, and phosphodiesterase 4.

    Science.gov (United States)

    Pospisil, Pavel; Kuoni, Thomas; Scapozza, Leonardo; Folkers, Gerd

    2002-01-01

    The docking methodology was applied to three different therapeutically interesting enzymes: human dihydroorotate dehydrogenase (DHODH), Herpes simplex virus type I thymidine kinase (HSV1 TK) and human phosphodiesterase 4 (PDE4). Programs FlexX, AutoDock and DOCK where used. The three targets represent three distinct cases. For DHODH and HSV1 TK, the binding modes of substrate and inhibitors within the active site are known, while the binding orientation of cAMP within PDE4 has been solely hypothesized. Active site of DHODH is mainly hydrophobic and the binding mode of the inhibitor brequinar was used as a template for evaluating the docking strategies. The presence of cofactors revealed to be crucial for the definition of the docking site. The HSV1 TK active site is small and polar and contains crystal water molecules and ATP. Docking of thymidine and aciclovir (ACV) within the active site was analyzed by keeping or removing water molecules. It showed the crucial role of water in predicting the binding of pyrimidines and purines. The crystal structure of PDE4 contains magnesium and zinc cations as well as catalytic water molecule but no ligand. Several docking experiments of cAMP and rolipram were performed and the results showed clear-cut dependence between the ligand orientation and the presence of metals in the active site. All three cases show specific problems of the docking methodology, depending on the character of the active site.

  19. Sensitivity and specificity of tritiated thymidine incorporation and ELISPOT assays in identifying antigen specific T cell immune responses

    Directory of Open Access Journals (Sweden)

    MacLeod Beth

    2007-09-01

    Full Text Available Abstract Background Standardization of cell-based immunologic monitoring is becoming increasingly important as methods for measuring cellular immunity become more complex. We assessed the ability of two commonly used cell-based assays, tritiated thymidine incorporation (proliferation and IFN-gamma ELISPOT, to predict T cell responses to HER-2/neu, tetanus toxoid (tt, and cytomegalovirus (CMV antigens. These antigens were determined to be low (HER-2/neu, moderate (tt, and robustly (CMV immunogenic proteins. Samples from 27 Stage II, III, and IV HER-2/neu positive breast cancer patients, vaccinated against the HER-2/neu protein and tt, were analyzed by tritiated thymidine incorporation and IFN-gamma ELISPOT for T cell response. Results Linear regression analysis indicates that both stimulation index (SI (p = 0.011 and IFN-gamma secreting precursor frequency (p Conclusion These data underscore the importance of taking into consideration the performance characteristics of assays used to measure T cell immunity. This consideration is particularly necessary when determining which method to utilize for assessing responses to immunotherapeutic manipulations in cancer patients.

  20. Enhanced Selectivity and Uptake Capacity of CO2 and Toluene Adsorption in Co0.5 M0.33 MoS4 (M= Sb or Y) Chalcogels by Impregnated Metal Salts

    KAUST Repository

    Adhiam, Fatima Abdullah Ahmed

    2017-11-17

    The synthesis of metal chalcogenide aerogels Co0.5M0.33MoS4 (M= Sb or Y) by the sol-gel method is reported. In this system, the building blocks [MoS4]2− chelated with Co2+ and (Sb3+) or (Y3+) salts in nonaqueous solvents forming amorphous networks with a gel property. The chalcogels obtained after supercritical drying have BET surface areas of 176 m2 g−1 (Co0.5Sb0.33MoS4) and 145 m2 g−1 (Co0.5Y0.33MoS4). Electron microscopy and physisorption studies reveal that the new materials are porous with wide pore size distribution and average pore width of 16 nm. These chalcogels show higher adsorption capacity of toluene vapor (Co0.5Sb0.33MoS4: 387 mg g−1) and (Co0.5Y0.33MoS4: 304 mg g−1) over cyclohexane vapor and high selectivity of CO2 over CH4 or H2, Co0.5Sb0.33MoS4 (CO2/H2: 80 and CO2/CH4: 21), Co0.5Y0.33MoS4 (CO2/H2: 27 and CO2/CH4: 15). We also demonstrated that the impregnation of various metal species like Li+, Mg2+, and Ni2+ significantly enhanced the uptake capacity and selectivity of toluene and CO2 adsorptions in the chacogels.

  1. Ablation of the ID2 gene results in altered circadian feeding behavior, and sex-specific enhancement of insulin sensitivity and elevated glucose uptake in skeletal muscle and brown adipose tissue.

    Directory of Open Access Journals (Sweden)

    Deepa Mathew

    Full Text Available Inhibitor of DNA binding 2 (ID2 is a helix-loop-helix transcriptional repressor rhythmically expressed in many adult tissues. Our earlier studies have demonstrated a role for ID2 in the input pathway, core clock function and output pathways of the mouse circadian system. We have also reported that Id2 null (Id2-/- mice are lean with low gonadal white adipose tissue deposits and lower lipid content in the liver. These results coincided with altered or disrupted circadian expression profiles of liver genes including those involved in lipid metabolism. In the present phenotypic study we intended to decipher, on a sex-specific basis, the role of ID2 in glucose metabolism and in the circadian regulation of activity, important components of energy balance. We find that Id2-/- mice exhibited altered daily and circadian rhythms of feeding and locomotor activity; activity profiles extended further into the late night/dark phase of the 24-hr cycle, despite mice showing reduced total locomotor activity. Also, male Id2-/- mice consumed a greater amount of food relative to body mass, and displayed less weight gain. Id2-/- females had smaller adipocytes, suggesting sexual-dimorphic programing of adipogenesis. We observed increased glucose tolerance and insulin sensitivity in male Id2-/- mice, which was exacerbated in older animals. FDG-PET analysis revealed increased glucose uptake by skeletal muscle and brown adipose tissue of male Id2-/- mice, suggesting increased glucose metabolism and thermogenesis in these tissues. Reductions in intramuscular triacylglycerol and diacylglycerol were detected in male Id2-/- mice, highlighting its possible mechanistic role in enhanced insulin sensitivity in these mice. Our findings indicate a role for ID2 as a regulator of glucose and lipid metabolism, and in the circadian control of feeding/locomotor behavior; and contribute to the understanding of the development of obesity and diabetes, particularly in shift work

  2. Optimal conditions in (/sup 3/H)-thymidine uptake studies to prevent radiation damage to cells. A scintimetric and cytofluorographic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Arguelles, A.; Llorente, L.; Diaz-Jouanen, E.; Alarcon-Segovia, D. (Instituto Nacional de la Nutricion, Mexico City)

    1981-12-01

    Cells subjected to nucleoside incorporation studies using radiolabelled materials may suffer radiation damage that can alter the results. Scintimetric and cytofluorographic analyses were performed to confirm this and to determine the optimal experimental doses of, and exposure times to, (/sup 3/H)-TdR, in order to prevent or minimize such radiation damage to cells. The results showed that cultures of human mononuclear cells should be pulsed with 0.125 ..mu..Ci for 14 hr when stimulated with phytohaemagglutinin, 0.125 ..mu..Ci for 18 hr when stimulated with pokeweed mitogen, 0.5 ..mu..Ci for 8 hr when stimulated with concanavalin A and 0.5 ..mu..Ci for 8 hr when subjected to allogeneic stimulus, in order to achieve optimal incorporation with minimal disturbances of the cell cycle.

  3. Facilitation of phosphorus uptake in maize plants by mycorrhizosphere bacteria

    National Research Council Canada - National Science Library

    Fabio Battini; Mette Grønlund; Monica Agnolucci; Manuela Giovannetti; Iver Jakobsen

    2017-01-01

    ...) and their associated bacteria could enhance growth and P uptake in maize. Plants were grown with or without mycorrhizas in compartmented pots with radioactive P tracers and were inoculated with each of 10 selected bacteria isolated from AMF spores...

  4. Preclinical and therapeutic utility of HVJ liposomes as a gene transfer vector for hepatocellular carcinoma using herpes simplex virus thymidine kinase.

    Science.gov (United States)

    Hasegawa, H; Shimada, M; Yonemitsu, Y; Utsunomiya, T; Gion, T; Kaneda, Y; Sugimachi, K

    2001-04-01

    Although gene therapy has been suggested to be a novel strategy to treat hepatocellular carcinoma (HCC), no study showing the clinical feasibility of vectors to treat HCC has been reported. In this preclinical study, we show evidence indicating that hemagglutinating virus of Japan (HVJ) liposomes are a feasible vector to treat HCC in a clinical setting using ganciclovir (GCV) and herpes simplex virus thymidine kinase (HSV-tk), which is driven by the cytomegalovirus immediate early enhancer/promoter (plasmid pcDNA3/HSV-tk). In in vitro experiments, almost complete tumor cell regression was achieved with the optimal GCV concentration (100 microg/mL) and more than 1/3 regression was seen even with a 20% transduction ratio using HuH7 HCC cells stably transformed by HSV-tk. HVJ liposomes showed a 19.7% (mean) transduction rate of the lacZ gene in a relatively large mass of more than 300 mm3 in vivo, which is a clinically detectable size, implanted into SCID mice. Moreover, a single HSV-tk injection of HVJ liposomes followed by GCV treatment inhibited tumor growth at least within a week, and repeat administration was more effective. Furthermore, subcutaneous injection of an HVJ liposomes vehicle induced no apparent inflammatory response in C3H/HeN mice, whereas lacZ gene transfection resulted in inflammatory pathology, suggesting a lower immunogenicity of the HVJ envelope protein than those of bacteria-derived plasmid DNA or the beta-galactosidase gene product. From these findings, we conclude that HVJ liposomes are a clinically safe and effective gene transfer vector to treat HCC.

  5. Increased muscle glucose uptake after exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Ploug, Thorkil; Galbo, Henrik

    1985-01-01

    It has recently been shown that insulin sensitivity of skeletal muscle glucose uptake and glycogen synthesis is increased after a single exercise session. The present study was designed to determine whether insulin is necessary during exercise for development of these changes found after exercise....... Diabetic rats and controls ran on a treadmill and their isolated hindquarters were subsequently perfused at insulin concentrations of 0, 100, and 20,000 microU/ml. Exercise increased insulin sensitivity of glucose uptake and glycogen synthesis equally in diabetic and control rats, but insulin...... responsiveness of glucose uptake was noted only in controls. Analysis of intracellular glucose-6-phosphate, glucose, glycogen synthesis, and glucose transport suggested that the exercise effect on responsiveness might be due to enhancement of glucose disposal. After electrical stimulation of diabetic...

  6. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... probe counter used for thyroid uptake exams. The patient sits with the camera directed at the neck for five minutes, and then the leg for ... Medicine Head and Neck Cancer Treatment Radioactive Iodine (I-131) Therapy Head and ...

  7. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head and Neck Cancer top of page ... and Neck Cancer Treatment Radioactive Iodine (I-131) Therapy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear ... to Thyroid Scan and Uptake ...

  8. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ... of a typical probe counter used for thyroid uptake exams. The patient sits with the camera directed at the neck for five minutes, and then the leg for ...

  9. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake ...

  10. Gold nanoparticle delivery of modified CpG stimulates macrophages and inhibits tumor growth for enhanced immunotherapy.

    Directory of Open Access Journals (Sweden)

    Adam Yuh Lin

    Full Text Available Gold nanoparticle accumulation in immune cells has commonly been viewed as a side effect for cancer therapeutic delivery; however, this phenomenon can be utilized for developing gold nanoparticle mediated immunotherapy. Here, we conjugated a modified CpG oligodeoxynucleotide immune stimulant to gold nanoparticles using a simple and scalable self-assembled monolayer scheme that enhanced the functionality of CpG in vitro and in vivo. Nanoparticles can attenuate systemic side effects by enhancing CpG delivery passively to innate effector cells. The use of a triethylene glycol (TEG spacer on top of the traditional poly-thymidine spacer increased CpG macrophage stimulatory effects without sacrificing DNA content on the nanoparticle, which directly correlates to particle uptake. In addition, the immune effects of modified CpG-AuNPs were altered by the core particle size, with smaller 15 nm AuNPs generating maximum immune response. These TEG modified CpG-AuNP complexes induced macrophage and dendritic cell tumor infiltration, significantly inhibited tumor growth, and promoted survival in mice when compared to treatments with free CpG.

  11. (18)F-fluoro-L-thymidine-PET for the evaluation of primary brain tumours in children: a report of three cases.

    NARCIS (Netherlands)

    Gilles, R.; Vogel, W.V.; Gidding, C.E.M.; Janssens, G.O.; Vliet, A.M. van der; Oyen, W.J.G.

    2010-01-01

    BACKGROUND: F-fluoro-L-thymidine (FLT) has been shown to be a useful PET tracer in the evaluation of brain tumours in adults. No studies of this modality in children with brain tumours, however, have been published. OBJECTIVE: In this report three children with brain tumours are presented in which

  12. F-18-fluoro-L-thymidine-PET for the evaluation of primary brain tumours in children: a report of three cases

    NARCIS (Netherlands)

    Gilles, R.; Vogel, W.V.; Gidding, C.E.M.; Janssens, G.O.R.J.; van der Vliet, T.M.; Oyen, W.J.G.

    2010-01-01

    Background F-18-fluoro-L-thymidine (FLT) has been shown to be a useful PET tracer in the evaluation of brain tumours in adults. No studies of this modality in children with brain tumours, however, have been published. Objective In this report three children with brain tumours are presented in which

  13. F-18-FEAU as a radiotracer for herpes simplex virus thymidine kinase gene expression : in-vitro comparison with other PET tracers

    NARCIS (Netherlands)

    Buursma, AR; Rutgers, [No Value; Hospers, GAP; Mulder, NH; Vaalburg, W; de Vries, EFJ

    Objective The herpes simplex virus thymidine kinase (HSVtk) gene has frequently been applied as a reporter gene for monitoring transgene expression in animal models. In clinical gene therapy protocols, however, extremely low expression levels of the transferred gene are generally observed.

  14. Effect of valine 106 on structure-function relation of cytosolic human thymidine kinase - Kinetic properties and oligomerization pattern of nine substitution mutants of V106

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Berenstein, Dvora; Munch-Petersen, Birgitte

    2004-01-01

    and characterized nine mutants of amino acid 106 differing in size, conformation and polarity. According to their oligomerization pattern and thymidine kinetics, the TK1 mutants can be divided into two groups. Group I (V106A, V106I and V106T) behaves like V106WT, in that pre-assay exposure to ATP induces reversible...

  15. Long-term foscarnet therapy remodels thymidine analogue mutations and alters resistance to zidovudine and lamivudine in HIV-1

    DEFF Research Database (Denmark)

    Mathiesen, Sofie; Dam, Elisabeth; Roge, Birgit

    2007-01-01

    OBJECTIVE: To study the evolution of multi-drug-resistant HIV-1 in treatment-experienced patients receiving foscarnet (PFA) as part of salvage therapy and to investigate the virological consequences of emerging mutations. METHODS: Genotypic and phenotypic resistance tests were performed on plasma...... viruses from seven patients at baseline and during treatment with PFA. The phenotypic effects of mutations suspected to be associated with PFA resistance were evaluated by site-directed mutagenesis of wild-type or thymidine analogue mutations (TAM)-carrying pNL4-3. Reversion of single mutations...... was performed in a patient-derived recombinant clone. RESULTS: Baseline multi-drug-resistant isolates exhibited hypersusceptibility to PFA. In two patients who received > 12 months of PFA treatment, a novel mutation pattern including K70G, V75T, K219R and L228R emerged. These viruses had 3-6-fold resistance...

  16. G1/S-regulated E2F-containing protein complexes bind to the mouse thymidine kinase gene promoter

    DEFF Research Database (Denmark)

    Dou, Q P; Zhao, S; Levin, A H

    1994-01-01

    By performing DNase I footprint analysis, we had identified three distinct protein binding sequences (MT1, MT2, and MT3) located on the mouse thymidine kinase (TK) upstream promoter (Dou, Q.-P., Fridovich-Keil, J. L., and Pardee, A.B. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 1157-1161). Here we....... (iii) Formation of both these DNA-protein complexes were cell cycle-dependent: a G0/G1 phase-specific complex (E2F.G0/G1) was replaced by an S phase-specific complex(es) (E2F.S), whereas "free" E2F increased after the G1/S transition. (iv) Pulse inhibition of protein synthesis with cycloheximide...

  17. Role of thymidine residues in DNA recognition by the EcoRI and EcoRV restriction endonucleases.

    Science.gov (United States)

    Fliess, A; Wolfes, H; Rosenthal, A; Schwellnus, K; Blöcker, H; Frank, R; Pingoud, A

    1986-04-25

    We have synthesized a series of oligonucleotides containing the EcoRI (GAATTC) or EcoRV (GATATC) recognition site within which or adjacent to which thymidine was substituted by uridine or derivatives of uridine. The effects of these substitutions on the rate of the EcoRI and EcoRV catalyzed cleavage reaction were investigated. Our results show that most of the substitutions within the site are quite well tolerated by EcoRI, not, however, by EcoRV. We conclude that the thymin residues most likely are not directly involved in the recognition process of the EcoRI reaction. In contrast, they are major points of contact, between substrate and enzyme in the EcoRV reaction. The effects of substitutions in the position adjacent to the recognition site is also markedly different for EcoRI and EcoRV. Here, EcoRI seems to be considerably more selective than EcoRV.

  18. Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C.F.

    1984-08-01

    The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

  19. A New Synthetic Compound, 2-OH, Enhances Interleukin-2 and Interferon-γ Gene Expression in Human Peripheral Blood Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    Woan-Fang Tzeng

    2009-07-01

    Full Text Available A new synthetic compound, 6-hydroxy-2-tosylisoquinolin-1(2H-one (2-OH, was selected for immunopharmacological activity tests. The effects of 2-OH on human peripheral blood mononuclear cell (PBMC proliferation were determined by tritiated thymidine uptake. Compared to phytohemagglutinin (PHA; 5 μg/mL stimulation, 2-OH significantly enhanced PBMC proliferation in a dose-dependent manner. The 50% enhancement activity (EC50 for 2-OH was 4.4±0.1 μM. In addition, effects of 2-OH on interleukin-2 (IL-2 and interferon-γ (IFN-γ production in PBMC were determined by enzyme immunoassay. Results demonstrated that 2-OH stimulated IL-2 and IFN-γ production in PBMC. Data from reverse transcription-polymerase chain reaction (RT-PCR and real-time PCR indicated that IL-2 and IFN-γ mRNA expression in PBMC could be induced by 2-OH. Therefore, 2-OH enhanced IL-2 and IFN-γ production in PBMC by modulation their gene expression. We suggest that 2-OH may be an immunomodulatory agent.

  20. Effect of rhamnolipids on the uptake of PAHs by ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, Zhejiang University, Hangzhou, Zhejiang 310029 (China)], E-mail: zlz@zju.edu.cn; Zhang Ming [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: zhangming@zju.edu.cn

    2008-11-15

    A hydroponic experiment was conducted to investigate the effect of rhamnolipids, a biosurfactant, on the uptake of polycyclic aromatic hydrocarbons (PAHs) by ryegrass. Results showed that rhamnolipids could enhance the uptake of PAHs by ryegrass roots. With increasing concentration of rhamnolipids, the PAH content in ryegrass roots initially increased and then decreased, while the PAH content in ryegrass shoots did not change. Batch studies also showed that the sorption of phenanthrene by fresh ryegrass roots was dependent on rhamnolipid concentration and showed the same trends as the uptake experiment. The increase of permeability of ryegrass root cells with the increase of rhamnolipid concentration may lead to the initial enhancement of PAH content in ryegrass roots, and the decrease of PAH adsorption onto the root surface with further increase of rhamnolipids led to the decrease of PAH content in ryegrass roots. - Rhamnolipids, a biosurfactant, can promote the uptake of PAHs by ryegrass, which indicates a potential application of surfactant-enhanced phytoremediation.

  1. [Influence of the selected pyrimidine compounds on the activity of thymidine phosphorylase from normal and tumor endometrial cells].

    Science.gov (United States)

    Miszczak-Zaborska, Elzbieta; Smolarek, Monika; Dramiński, Marcin; Kubiak, Robert; Józwiak, Barbara; Bartkowiak, Jacek

    2009-08-01

    The aim of this study was to evaluate the influence of the selected pyrimidine compounds on the activity of thymidine phosphorylase (TP) of normal and tumor endometrial cells. Influence of 28 chemical compounds on the TP activity in the cytosol of the endometrial cells was studied by the spectrophotometric method. The studied group comprised postmenopausal women with endometrial cancer: adenocarcinoma endometrialis (Adeno Ca E). The second group included women with normal endometrium after surgery due to non-oncologic reasons. The most potent inhibitor of TP activity from cancer and endometrium was synthesized 5-bromo-6-acetyloaminouracil, which at the 0.2 mM concentration, by 0.2 mM concentration thymidine reduced the cytosol TP activity by about 80%. 5-bromo-6-aminouracil, 5-nitrouracil and 5-bromouracil reduced this TP activity in statistically significant manner. From among synthesized 1-N-allyloxymethylpyrimidine derivatives 1-N-allyloxymethylthymine was the strongest inhibitor of the TP activity in endometrium, and 1-N-allyloxymethyl-4-hydrokxy-5-nitro-6-oxopyrimidine in endometrial cancer respectively. The most potent activators of TP in endometrial cancer was 5-bromodeoxyuridine and 1-N-allyloxymethyl-5-nitrouracil, which increased the TP activity about 100%. 5-fluorodeoxyuridine, 5-jododeoxyuridine and 2'-deoxyuridine activated the TP in statistically significant manner too, but stronger in case of endometrial cancer than in normal endometrium. The synthesized 5-bromo-6-acetyloaminouracil strongly inhibited the TP activity of endometrial cells and might be useful in reducing endometrial cancer angiogenesis. On the other hand 5-bromodeoxyuridine and the synthesized 1-N-allyloxymethyl-5-nitrouracil might increase the effect of antitumor therapy with the cytostatics. These conclusions ought to be confirmed by analyzing more tumor cases.

  2. Non-invasive in vivo imaging with radiolabelled FIAU for monitoring cancer gene therapy using herpes simplex virus type 1 thymidine kinase and ganciclovir

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Win-Ping; Lai, Wen-Fu [Graduate Institute of Biomedical Materials, Taipei Medical University, Taipei (Taiwan); Yang, Wen K.; Yang, Den-Mei [Institute of Biological Science, Academic Sinica, Taipei (Taiwan); Liu, Ren-Shyan [Department of Nuclear Medicine and National PET Cyclotron Center, Veterans General Hospital, Taipei (Taiwan); Hwang, Jeng-Jong; Wang, Hsin-Ell [Institute of Radiological Science, National Yang-Ming University, 155, Sec. 2, Lih-Nong Street, 112, Pei-tou, Taipei (Taiwan); Fu, Ying-Kai [Institute of Nuclear Energy, Atomic Energy Council, Taoyuan (Taiwan)

    2004-01-01

    An experimental cancer gene therapy model was employed to develop a non-invasive imaging procedure using radiolabelled 2'-fluoro-2'-deoxy-5-iodo-1-{beta}-d-arabinofuranosyluracil (FIAU) as an enzyme substrate for monitoring retroviral vector-mediated herpes simplex virus type 1 thymidine kinase gene (HSV1-tk) transgene expression. Iodine-131 labelled FIAU was prepared by a no-carrier-added (n.c.a.) synthesis process and lyophilised to give ''hot kits''. The labelling yield was over 95%, with a radiochemical purity of more than 98%. The stability of [{sup 131}I]FIAU in the form of lyophilised powder (the hot kit) was much better than that in the normal saline solution. The shelf life of the final [{sup 131}I]FIAU hot kit product is as long as 4 weeks. Cellular uptake of [{sup 131}I]FIAU after different periods of storage was investigated in vitro with HSV1-tk-retroviral vector transduced NG4TL4-STK and parental non-transduced NG4TL4 murine sarcoma cell lines over an 8-h incubation period. The NG4TL4-STK cells accumulated more radioactivity than NG4TL4 cells in all conditions, and accumulation increased with time up to 8 h. The kinetic profile of the cellular uptake of n.c.a. [{sup 131}I]FIAU formulated from the lyophilised hot kit or from the stock solution was qualitatively similar. For animal model cancer gene therapy studies, FVB/N mice were inoculated subcutaneously with the HSV1-tk(+) and tk(-) sarcoma cells into the flank to produce tumours. Biodistribution studies showed that tumour/blood ratios were 2, 3.5, 8.2 and 386.8 at 1, 4, 8 and 24 h post injection, respectively, for the HSV1-tk(+) tumours, and 0.5, 0.5, 0.7 and 5.4, respectively, for the HSV1-tk(-) tumours. Radiotracer clearance from blood was completed in 24 h and was bi-exponential. A significant difference in radioactivity accumulation was revealed among the HSV1-tk(+) tumours, the tk(-) tumours and other tissues. At 24 h p.i., higher activity retention was observed

  3. Effect of Human Saliva on Glucose Uptake by Streptococcus mutans and Other Oral Microorganisms

    OpenAIRE

    Germaine, Greg R.; Tellefson, Lois M.

    1981-01-01

    We examined the effects of human whole salivary supernatant and parotid fluid on glucose uptake by Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, Staphylococcus aureus, and Escherichia coli. The following three effects of saliva were observed: (i) inhibition of glucose uptake (S. mutans, S. sanguis), (ii) promotion of a transient, rapid (0 to 30 s) burst of glucose uptake (S. mutans, S. sanguis), and (iii) enhancement of glucose uptake (S. mitis, A. vi...

  4. Putrescine uptake in saintpaulia petals.

    Science.gov (United States)

    Bagni, N; Pistocchi, R

    1985-02-01

    Putrescine uptake and the kinetics of this uptake were studied in petals of Saintpaulia ionantha Wendl. Uptake experiments of [(3)H] or [(14)C] putrescine were done on single petals at room temperature at various pH values. The results show that putrescine uptake occurs against a concentration gradient at low external putrescine concentration (0.5-100 micromolar) and follows a concentration gradient at higher external putrescine concentrations (100 micromolar to 100 millimolar). 2,4-Dinitrophenol and carbonylcyanide-m-chlorophenylhydrazone, two uncouplers, had no effect on putrescine uptake. Uptake rates were constant for 2 hours, reaching a maximum after 3 to 4 hours. Putrescine uptake depended markedly on the external pH and two maxima were observed: at low external concentrations of putrescine, the optimum was at pH 5 to 5.5; at higher concentrations the optimum was at pH 8.

  5. Estudos in vitro e in vivo de análogo da timidina marcada com complexo organometálico de tecnécio-99m para potencial uso em diagnóstico tumoral Studies in vitro and in vivo of thymidine analog labeled with organometalic complex of technetium-99m for potential use in tumor diagnosis

    Directory of Open Access Journals (Sweden)

    Rodrigo Luis Silva Ribeiro Santos

    2008-03-01

    -carbonyl, thymidine labeling with this precursor, study of stability, and radiochemical e biological evaluation with healthy and tumor-bearing animals. The organometallic precursor and the labeling of thymidine with this precursor were resulted with a radiochemical pureness of > 97% and > 94%, respectively, with good radiochemical stability up to 6 h in room temperature. The cysteine and histidine challenge indicated losses between 8 and 11% for concentrations until 300 mM. The biodistribution assay in healthy mice revealed rapid blood clearance and low uptake by general organs with renal and hepatobiliary excretion. The tumor concentration was of 0.28 and 0.18 %ID/g for lung and breast cancer, respectively. The results imply more studies in other thymidine analogs.

  6. Exosomes: Mechanisms of Uptake

    Directory of Open Access Journals (Sweden)

    Kelly J. McKelvey

    2015-07-01

    Full Text Available Exosomes are 30–100 nm microvesicles which contain complex cellular signals of RNA, protein and lipids. Because of this, exosomes are implicated as having limitless therapeutic potential for the treatment of cancer, pregnancy complications, infections, and autoimmune diseases. To date we know a considerable amount about exosome biogenesis and secretion, but there is a paucity of data regarding the uptake of exosomes by immune and non-immune cell types (e.g., cancer cells and the internal signalling pathways by which these exosomes elicit a cellular response. Answering these questions is of paramount importance.

  7. Exosomes: Mechanisms of Uptake

    Directory of Open Access Journals (Sweden)

    Kelly J. McKelvey

    2015-07-01

    Full Text Available Exosomes are 30–100 nm microvesicles which contain complex cellular signals of RNA, protein and lipids. Because of this, exosomes are implicated as having limitless therapeutic potential for the treatment of cancer, pregnancy complications, infections, and autoimmune diseases. To date we know a considerable amount about exosome biogenesis and secretion, but there is a paucity of data regarding the uptake of exosomes by immune and non- immune cell types (e.g., cancer cells and the internal signalling pathways by which these exosomes elicit a cellular response. Answering these questions is of para‐ mount importance.

  8. Integrated homology modelling and X-ray study of herpes simplex virus I thymidine kinase: a case study.

    Science.gov (United States)

    Folkers, G; Alber, F; Amrhein, I; Behrends, H; Bohner, T; Gerber, S; Kuonen, O; Scapozza, L

    1997-01-01

    Knowledge-based homology modelling together with site-directed mutagenesis, epitope and conformational mapping is an approach to predict the structures of proteins and for the rational design of new drugs. In this study we present how this procedure has been applied to model the structure of herpes simplex virus type 1 thymidine kinase (HSV1 TK, HSV1 ATP-thymidine-5'-phosphotransferase, EC 2.7.1.21). We have used, and evaluated, several secondary structure prediction methods, such as the classical one based on Chou and Fastman algorithm, neural networks using the Kabsch and Sander classification, and the PRISM method. We have validated the algorithms by applying them to the porcine adenylate kinase (ADK), whose three-dimensional structure is known and that has been used for the alignment of the TKs as well. The resulting first model of HSV1-TK consisted of the first beta-strand connected to the phosphate binding loop and its subsequent alpha-helix, the fourth beta-strand connected to the conserved FDRH sequence and two alpha-helix with basic amino acids. The 3D structure was built using the X-ray structure of ADK as template and following the general procedure for homology modelling. We extended the model by means of COMPOSER, an automatic process for protein modelling. Site-directed mutagenesis was used to experimentally verify the predicted active-site model of HSV1-TK. The data measured in our lab and by others support the suggestion that the FDRH motif is part of the active site and plays an important role in the phosphorylation of substrates. The structure of HSV1 TK, recently solved in collaboration with Prof. G. Schulz at 2.7 A resolution, includes 284 of 343 residues of the N-terminal truncated TK. The secondary structures could be clearly assigned and fitted to the density. The comparison between crystallographically determined structure and the model shows that nearly 70% of the HSV1 TK structure has been correctly modelled by the described integrated

  9. Inositol uptake in rat aorta

    Energy Technology Data Exchange (ETDEWEB)

    Rapoport, R.M.; Van Gorp, C.; Chang, Ki-Churl (Univ. of Cincinnati College of Medicine, OH (USA))

    1990-01-01

    {sup 3}H-inositol uptake into deendothelialized aorta was linear for at least 2 h and was composed of both a saturable, Na{sup +}-dependent, and a nonsaturable, Na{sup +}-independent component. The Na{sup +}-dependent component of inositol uptake had a K{sub m} of 50 {mu}M and a V{sub max} of 289 pmol/mg prot/h. Exposure to LiCl, ouabain, or Ca{sup 2+} - free Krebs-Ringer bicarbonate solution inhibited uptake. Metabolic poisoning with dinitrophenol, as well as incubation with phloretin, an inhibitor of carrier-mediated hexose transport, also inhibited uptake. Exposure to norepinephrine decreased inositol uptake, while phorbol myristate acetate was without effect. Isobutylmethylxanthine significantly increased inositol uptake, while the increased uptake due to dibutyryl cyclic AMP and forskolin were not statistically significant. Sodium nitroprusside, and activator of guanylate cyclase, and 8-bromo cyclic GMP, were without effect on uptake, as was methylene blue, an inhibitor of guanylate cyclase. Inositol uptake into the aorta was increased when the endothelium was allowed to remain intact, although this effect was likely due to uptake in both the endothelial and smooth muscle cells.

  10. Impact of HIV-1 reverse transcriptase polymorphism F214L on virological response to thymidine analogue-based regimens in antiretroviral therapy (ART)-naive and ART-experienced patients

    DEFF Research Database (Denmark)

    Ceccherini-Silberstein, Francesca; Cozzi-Lepri, Alessandro; Ruiz, Lidia

    2007-01-01

    A negative association between the polymorphism F214L and type 1 thymidine analogue (TA) mutations (TAMs) has been observed. However, the virological response to TAs according to the detection of F214L has not been evaluated....

  11. X-ray structures of uridine phosphorylase from Vibrio cholerae in complexes with uridine, thymidine, uracil, thymine, and phosphate anion: Substrate specificity of bacterial uridine phosphorylases

    Energy Technology Data Exchange (ETDEWEB)

    Prokofev, I. I.; Lashkov, A. A., E-mail: alashkov83@gmail.com; Gabdulkhakov, A. G.; Balaev, V. V.; Seregina, T. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Mironov, A. S. [State Research Institute of Genetics and Selection of Industrial Microorganisms (Russian Federation); Betzel, C. [University of Hamburg (Germany); Mikhailov, A. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation)

    2016-11-15

    In many types of human tumor cells and infectious agents, the demand for pyrimidine nitrogen bases increases during the development of the disease, thus increasing the role of the enzyme uridine phosphorylase in metabolic processes. The rational use of uridine phosphorylase and its ligands in pharmaceutical and biotechnology industries requires knowledge of the structural basis for the substrate specificity of the target enzyme. This paper summarizes the results of the systematic study of the three-dimensional structure of uridine phosphorylase from the pathogenic bacterium Vibrio cholerae in complexes with substrates of enzymatic reactions—uridine, phosphate anion, thymidine, uracil, and thymine. These data, supplemented with the results of molecular modeling, were used to consider in detail the structural basis for the substrate specificity of uridine phosphorylases. It was shown for the first time that the formation of a hydrogen-bond network between the 2′-hydroxy group of uridine and atoms of the active-site residues of uridine phosphorylase leads to conformational changes of the ribose moiety of uridine, resulting in an increase in the reactivity of uridine compared to thymidine. Since the binding of thymidine to residues of uridine phosphorylase causes a smaller local strain of the β-N1-glycosidic bond in this the substrate compared to the uridine molecule, the β-N1-glycosidic bond in thymidine is more stable and less reactive than that in uridine. It was shown for the first time that the phosphate anion, which is the second substrate bound at the active site, interacts simultaneously with the residues of the β5-strand and the β1-strand through hydrogen bonding, thus securing the gate loop in a conformation.

  12. Deoxyribonucleoside kinases belonging to the thymidine kinase 2 (TK2)-like group vary significantly in substrate specificity, kinetics and feed-back regulation.

    Science.gov (United States)

    Knecht, Wolfgang; Petersen, Gitte Ebert; Munch-Petersen, Birgitte; Piskur, Jure

    2002-01-25

    In eukaryotic cells deoxyribonucleoside kinases belonging to three phylogenetic sub-families have been found: (i) thymidine kinase 1 (TK1)-like enzymes, which are strictly pyrimidine deoxyribonucleoside-specific kinases; (ii) TK2-like enzymes, which include pyrimidine deoxyribonucleoside kinases and a single multisubstrate kinase from Drosophila melanogaster (Dm-dNK); and (iii) deoxycytidine/deoxyguanosine kinase (dCK/dGK)-like enzymes, which are deoxycytidine and/or purine deoxyribonucleoside-specific kinases. We cloned and characterized two new deoxyribonucleoside kinases belonging to the TK2-like group from the insect Bombyx mori and the amphibian Xenopus laevis. The deoxyribonucleoside kinase from B. mori (Bm-dNK) turned out to be a multisubstrate kinase like Dm-dNK. But uniquely for a deoxyribonucleoside kinase, Bm-dNK displayed positive cooperativity with all four natural deoxyribonucleoside substrates. The deoxyribonucleoside kinase from X. laevis (Xen-PyK) resembled closely the human and mouse TK2 enzymes displaying their characteristic Michaelis-Menten kinetic with deoxycytidine and negative cooperativity with its second natural substrate thymidine. Bm-dNK, Dm-dNK and Xen-PyK were shown to be homodimers. Significant differences in the feedback inhibition by deoxyribonucleoside triphosphates between these three enzymes were found. The insect multisubstrate deoxyribonucleoside kinases Bm-dNK and Dm-dNK were only inhibited by thymidine triphosphate, while Xen-PyK was inhibited by thymidine and deoxycytidine triphosphate in a complex pattern depending on the deoxyribonucleoside substrate. The broad substrate specificity and different feedback regulation of the multisubstrate insect deoxyribonucleoside kinases may indicate that these enzymes have a different functional role than the other members of the TK2-like group. Copyright 2002 Academic Press.

  13. Pd-catalyzed Suzuki-Miyaura coupling reaction in the synthesis of 5-aryl-1-[2-(phosphonomethoxy)ethyl]uracils as potential multisubstrate inhibitors of thymidine phosphorylase

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Holý, Antonín; Pohl, Radek

    2007-01-01

    Roč. 48, č. 17 (2007), s. 3065-3067 ISSN 0040-4039 R&D Projects: GA MŠk 1M0508 Grant - others: Descartes Prize(XE) HPAW-CT-2002-9001 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * Suzuki coupling * pyrimidine Subject RIV: CC - Organic Chemistry Impact factor: 2.615, year: 2007

  14. The thymidine kinase-1 as a potential tumor marker: structure, function, activity in normal and malignant tissues

    Directory of Open Access Journals (Sweden)

    N. S. Sergeeva

    2017-01-01

    Full Text Available In the review the role of the thymidine kinase (TK to ensure the replication of DNA de novo and spare (salvage the way in health and activate alternate ways in carcinogenesis is described. The structure of cytoplasmic TK (TК-1, also called fetal, and the level of regulation of its activity in the cells and their change during the cell cycle is described. Considering the data about the absence of TK-1 in resting (G0 cells, TK-1 is positioned as a marker of proliferating cells, which activity is recorded from late G1 phase, peaking in S-phase, it is stored in the G2 and mitosis, quickly decreasing to undetectable levels in the early G1 phase. Data on the expression TK-1 (as compared with Ki-67 and PCNA (proliferating cell nuclear antigen in tumor tissues (colorectal, breast, cervical, lung, renal, prostate and ovarian cancer, as well as some benign and precancerous pathological processes in relation to the clinical and diagnostic features of these processes are systemized. These data suggest that the proliferative index studies on TK-1 (antibody to the domain HRA-210 should be used together with Ki-67 and PCNA, for a more complete assessment of the proliferative status of malignant tumors and pre-cancerous and benign conditions, with the aim of prognosis of the tumor process and treatment planning.

  15. Labelling indices after /sup 3/H-thymidine incorporation during organ culture of duodenal mucosa in coeliac disease

    Energy Technology Data Exchange (ETDEWEB)

    Fluge, G.; Aksnes, L. (Bergen Univ. (Norway))

    1980-01-01

    Incorporation of /sup 3/H-thymidine during organ culture of duodenal biopsy specimens from 34 coeliac and 10 non-coeliac patients was studied by autoradiography. High labelling indices were found in flat, coeliac mucosas. Gluten fractions, which provoked histological deterioration during culture, induced labelling of a greater proportion of crypt cells and higher migration rate than parallelly cultured specimens on gluten-free medium. No influence on clypt cell kinetics could be observed after culture with gluten fractions incapable of producing histological damage or with alpha-lactalbumin. In coeliac remission mucosas, labelling indices were at the same level as in non-coeliac biopsis, and no significant effects of gluten were observed. Autoradiography seems to be a fairly sensitive and reliable determinant of gluten toxicity by organ culture in coeliac desease and should supplement the histological appraisal of the biopsies. The increment of labelling indices provoked by gluten exposure seemed not merely to be a concequence of increased desquamation of cells from the biopsy surface but could imply a direct influence of gluten on crypt cell kinetics in coeliac disease.

  16. Imaging of Sleeping Beauty-Modified CD19-Specific T Cells Expressing HSV1-Thymidine Kinase by Positron Emission Tomography.

    Science.gov (United States)

    Najjar, Amer M; Manuri, Pallavi R; Olivares, Simon; Flores, Leo; Mi, Tiejuan; Huls, Helen; Shpall, Elizabeth J; Champlin, Richard E; Turkman, Nashaat; Paolillo, Vincenzo; Roszik, Jason; Rabinovich, Brian; Lee, Dean A; Alauddin, Mian; Gelovani, Juri; Cooper, Laurence J N

    2016-12-01

    We have incorporated a positron emission tomography (PET) functionality in T cells expressing a CD19-specific chimeric antigen receptor (CAR) to non-invasively monitor the adoptively transferred cells. We engineered T cells to express CD19-specific CAR, firefly luciferase (ffLuc), and herpes simplex virus type-1 thymidine kinase (TK) using the non-viral-based Sleeping Beauty (SB) transposon/transposase system adapted for human application. Electroporated primary T cells were propagated on CD19(+) artificial antigen-presenting cells. After 4 weeks, 90 % of cultured cells exhibited specific killing of CD19(+) targets in vitro, could be ablated by ganciclovir, and were detected in vivo by bioluminescent imaging and PET following injection of 2'-deoxy-2'-[(18)F]fluoro-5-ethyl-1-β-D-arabinofuranosyl-uracil ([(18)F]FEAU). This is the first report demonstrating the use of SB transposition to generate T cells which may be detected using PET laying the foundation for imaging the distribution and trafficking of T cells in patients treated for B cell malignancies.

  17. Thymidine phosphorylase is both a therapeutic and a suicide gene in a murine model of mitochondrial neurogastrointestinal encephalomyopathy.

    Science.gov (United States)

    López-Estévez, S; Ferrer, G; Torres-Torronteras, J; Mansilla, M J; Casacuberta-Serra, S; Martorell, L; Hirano, M; Martí, R; Barquinero, J

    2014-07-01

    Suicide gene therapy (SGT) is a promising strategy for treating cancer. In this work, we show that thymidine phosphorylase (TP) deficiency, the underlying genetic defect in mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), presents an opportunity to apply SGT using capecitabine, a commonly used prodrug that is converted into 5-fluorouracil by TP. Using an immortalised B-lymphoblastoid cell line from a patient with MNGIE, the tumourigenic EL-4 cell line, lentiviral vectors encoding TP and a double knockout (Tymp(-/-)Upp1(-/-)) murine model, we found that EL-4 cell-derived TP(+) tumours were exquisitely sensitive to capecitabine and generated a significant local bystander effect. In addition, we detected a spontaneous cytolytic immune response in a significant fraction of the animals surviving more than 20 days after termination of the therapy. These data indicate that, in individuals lacking TP expression, TP is a highly specific suicide gene, which can be used to treat tumours that could hypothetically arise in MNGIE patients undergoing gene therapy, as these tumours will likely originate from the gene-modified cells and will be selectively targeted by capecitabine. These observations have important implications for gene therapy for MNGIE.

  18. An Adenovirus Vector Containing the Suicide Gene Thymidine Kinase for a Broad Application in Cancer Gene Therapy

    Directory of Open Access Journals (Sweden)

    Magalhães GS

    2002-01-01

    Full Text Available Treatment of cancer using gene therapy is based on adding a property to the cell leading to its elimination. One possibility is the use of suicide genes that code for enzymes that transform a pro-drug into a cytotoxic product. The most extensively used is the herpes simplex virus thymidine kinase (TK gene, followed by administration of the antiviral drug ganciclovir (GCV. The choice of the promoter to drive the transcription of a transgene is one of the determinants of a given transfer vector usefulness, as different promoters show different efficiencies depending on the target cell type. In the experiments presented here, we report the construction of a recombinant adenovirus carrying TK gene (Ad-TK driven by three strong promoters (P CMV IE, SV40 and EN1 and its effectiveness in two cell types. Human HeLa and mouse CCR2 tumor cells were transduced with Ad-TK and efficiently killed after addition of GCV. We could detect two sizes of transcripts of TK gene, one derived from the close together P CMV IE/SV40 promoters and the other from the 1.5 Kb downstream EN1 promoter. The relative amounts of these transcripts were different in each cell type thus indicating a higher flexibility of this system.

  19. Ultrasound-targeted microbubble destruction mediated herpes simplex virus-thymidine kinase gene treats hepatoma in mice

    Directory of Open Access Journals (Sweden)

    Gong Jianping

    2010-12-01

    Full Text Available Abstract Objective The purpose of the study was to explore the anti-tumor effect of ultrasound -targeted microbubble destruction mediated herpes simplex virus thymidine kinase (HSV-TK suicide gene system on mice hepatoma. Methods Forty mice were randomly divided into four groups after the models of subcutaneous transplantation tumors were estabilished: (1 PBS; (2 HSV-TK (3 HSV-TK+ ultrasound (HSV-TK+US; (4 HSV-TK+ultrasound+microbubbles (HSV-TK+US+MB. The TK protein expression in liver cancer was detected by western-blot. Applying TUNEL staining detected tumor cell apoptosis. At last, the inhibition rates and survival time of the animals were compared among all groups. Results The TK protein expression of HSV-TK+MB+US group in tumor-bearing mice tissues were significantly higher than those in other groups. The tumor inhibitory effect of ultrasound-targeted microbubble destruction mediated HSV-TK on mice transplantable tumor was significantly higher than those in other groups (p Conclusion Ultrasound-targeted microbubble destruction can effectively transfect HSV-TK gene into target tissues and play a significant inhibition effect on tumors, which provides a new strategy for gene therapy in liver cancer.

  20. Usage of adenovirus expressing thymidine kinase mediated hepatocellular damage for enabling mouse liver repopulation with allogenic or xenogenic hepatocytes.

    Directory of Open Access Journals (Sweden)

    Daniel Moreno

    Full Text Available It has been shown that the liver of immunodeficient mice can be efficiently repopulated with human hepatocytes when subjected to chronic hepatocellular damage. Mice with such chimeric livers represent useful reagents for medical and clinical studies. However all previously reported models of humanized livers are difficult to implement as they involve cross-breeding of immunodeficient mice with mice exhibiting genetic alterations causing sustained hepatic injury. In this paper we attempted to create chimeric livers by inducing persistent hepatocellular damage in immunodeficient Rag2(-/- γc(-/- mice using an adenovirus encoding herpes virus thymidine kinase (AdTk and two consecutive doses of ganciclovir (GCV. We found that this treatment resulted in hepatocellular damage persisting for at least 10 weeks and enabled efficient engraftment and proliferation within the liver of either human or allogenic hepatocytes. Interestingly, while the nodules generated from the transplanted mouse hepatocytes were well vascularized, the human hepatocytes experienced progressive depolarization and exhibited reduced numbers of murine endothelial cells inside the nodules. In conclusion, AdTk/GCV-induced liver damage licenses the liver of immunodeficient mice for allogenic and xenogenic hepatocyte repopulation. This approach represents a simple alternative strategy for chimeric liver generation using immunodeficient mice without additional genetic manipulation of the germ line.

  1. N-H Stretching Excitations in Adenosine-Thymidine Base Pairs in Solution: Base Pair Geometries, Infrared Line Shapes and Ultrafast Vibrational Dynamics

    Science.gov (United States)

    Greve, Christian; Preketes, Nicholas K.; Fidder, Henk; Costard, Rene; Koeppe, Benjamin; Heisler, Ismael A.; Mukamel, Shaul; Temps, Friedrich; Nibbering, Erik T. J.; Elsaesser, Thomas

    2013-01-01

    We explore the N-H stretching vibrations of adenosine-thymidine base pairs in chloroform solution with linear and nonlinear infrared spectroscopy. Based on estimates from NMR measurements and ab initio calculations, we conclude that adenosine and thymidine form hydrogen bonded base pairs in Watson-Crick, reverse Watson-Crick, Hoogsteen and reverse Hoogsteen configurations with similar probability. Steady-state concentration- and temperature dependent linear FT-IR studies, including H/D exchange experiments, reveal that these hydrogen-bonded base pairs have complex N-H/N-D stretching spectra with a multitude of spectral components. Nonlinear 2D-IR spectroscopic results, together with IR-pump-IR-probe measurements, as also corroborated by ab initio calculations, reveal that the number of N-H stretching transitions is larger than the total number of N-H stretching modes. This is explained by couplings to other modes, such as an underdamped low-frequency hydrogen-bond mode, and a Fermi resonance with NH2 bending overtone levels of the adenosine amino-group. Our results demonstrate that modeling based on local N-H stretching vibrations only is not sufficient and call for further refinement of the description of the N-H stretching manifolds of nucleic acid base pairs of adenosine and thymidine, incorporating a multitude of couplings with fingerprint and low-frequency modes. PMID:23234439

  2. Influence of sodium humate on the uptake or some ions by tomato seedlings

    Directory of Open Access Journals (Sweden)

    Stefan Gumiński

    2014-01-01

    Full Text Available The influence of sodium humate on the uptake of K+, Rb+ NH4+, Mg2+, Fe3+ PO43-, NO3- and Cl- ions from equilibrated aqueous solutions was investigated. By varying transpiration and applying dinitrophenol "passive" and "active" uptake were distinguished. Ion decrease in the solution and accumulation of labelled elements in roots and shoots were determined. Humate strongly stimulated K+ and Rb+ uptake and strongly inhibited the uptake of Cl-, while it slightly enhanced Mg+2 and PO43- uptake. It, moreover, facilitated iron transport from the roots to shoots. The interaction of humate with dinitrophenol is discussed.

  3. Uptake of nuclides by plants

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2004-04-01

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

  4. Further advances in modeling transdermal uptake of SVOCs

    DEFF Research Database (Denmark)

    Morrison, Glenn; Weschler, Charles J.; Bekö, Gabriel

    2016-01-01

    To better simulate dermal uptake of SVOCs from air, we develop an enhanced transport model that includes skin surface lipids (SSL). As modeled, clothing can remove SSL by contact transfer and it can act as a source or sink for gas-phase transfer to and from SSL. Addition of SSL increases the over......To better simulate dermal uptake of SVOCs from air, we develop an enhanced transport model that includes skin surface lipids (SSL). As modeled, clothing can remove SSL by contact transfer and it can act as a source or sink for gas-phase transfer to and from SSL. Addition of SSL increases...... the overall resistance to uptake of SVOCs from air but also allows for more rapid release of SVOCs to sinks like clothing or clean air. We compare the model results to reported experimental uptake of di-ethyl phthalate (DEP) and di-n-butyl phthalate (DnBP), normalized by exposed skin area and the phthalate...... air concentration during exposure (Weschler et al., 2015). Overall, the model predicts total uptake values that are consistent with those observed in the experiments. The model predicts a normalized mass uptake of DEP of 3.1 (µg/m2)/(µg/m3) whereas the experimental results range from 1.0 to 4.3 (µg/m2...

  5. Characterization of cadmium uptake by the water lily Nymphaea aurora.

    Science.gov (United States)

    Schor-Fumbarov, Tamar; Keilin, Zvika; Tel-Or, Elisha

    2003-01-01

    This study characterizes cadmium (Cd) uptake by the waterlily Nymphaea aurora, (Nymphaeaceae) in two systems: a model hydroponic Cd solution and heavily polluted sludge from two sites in Israel. The uptake of Cd from hydroponic solution resulted in Cd storage in petioles and laminae of Nymphaea, as well as in the roots. The pH of the solution affected Cd solubility and availability, with pH 5.5 yielding maximum Cd content in the plant (140 mg Cd per g DW). Cd uptake was reduced by the addition of EDTA to the hydroponic growth medium, although EDTA enhanced heavy metal uptake by terrestrial plants. Nymphaea efficiently reduced the concentration of Cd in heavy metal polluted urban and industrial sludge and the amount of Cd uptake was enhanced by the addition of KCl to the sludge and by adjustment of the pH to 5.5. The inherent growth patterns of Nymphaea plants allowed Cd uptake by the shoot and root, and resulted in maximum contact between the various plant parts and the growth media. Thus, Nymphaea has potential as an optimal, highly effective phytoremediation tool for the removal of Cd from polluted waste sources.

  6. Cellular uptake mechanisms of novel anionic siRNA lipoplexes.

    Science.gov (United States)

    Kapoor, Mamta; Burgess, Diane J

    2013-04-01

    To investigate cellular uptake pathways of novel anionic siRNA-lipoplexes as a function of formulation composition. Anionic formulations with anionic lipid/Ca(2+)/siRNA ratio of 1.3/2.5/1 (AF1) and 1.3/0.3/1 (AF2) were utilized. Uptake mechanisms were investigated using uptake inhibition and co-localization approaches in breast cancer cells. Actin-mediated uptake was investigated using actin polymerization and rearrangement assays. Silencing efficiency and endosomal escaping capability of lipoplexes were evaluated. The cationic formulation Lipofectamine-2000 was used as a control. Anionic lipoplexes entered the breast cancer cells via endocytosis specifically via macropinocytosis or via both macropinocytosis and HSPG (heparin sulfate proteoglycans) pathways, depending on the Ca(2+)/siRNA ratio. Additionally, uptake of these lipoplexes was both microtubule and actin dependent. The control cationic lipid-siRNA complexes (Lipofectamine-2000) were internalized via both endocytic (phagocytosis, HSPG) and non-endocytic (membrane fusion) pathways. Their uptake was microtubule independent but actin dependent. Silencing efficiency of the AF2 formulation was negligible mainly due to poor endosomal release (rate-limiting step). Formulation composition significantly influences the internalization mechanism of anionic lipoplexes. Uptake mechanism together with formulation bioactivity helped in identification of the rate-limiting steps to efficient siRNA delivery. Such studies are extremely useful for formulation optimization to achieve enhanced intracellular delivery of nucleic acids.

  7. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney

    Directory of Open Access Journals (Sweden)

    N. L. Rukavina Mikusic

    2016-01-01

    Full Text Available Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP and Ang-(1-7 may regulate renal dopamine availability in tubular cells, contributing to Na+, K+-ATPase inhibition. Present results show that CNP did not affect either 3H-dopamine uptake in renal tissue or Na+, K+-ATPase activity; meanwhile, Ang-(1-7 was able to increase 3H-dopamine uptake and decreased Na+, K+-ATPase activity in renal cortex. Ang-(1-7 and dopamine together decreased further Na+, K+-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7 stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide did not modify CNP effects on 3H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7 on 3H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7 was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7 on AT1 receptors on 3H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7 enhances Na+, K+-ATPase activity inhibition, contributing to its natriuretic and diuretic effects.

  8. Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice.

    Science.gov (United States)

    Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu; Hsu, Sheng-Min; Chen, Shun-Hua

    2017-02-15

    Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484-490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of immunocompromised

  9. GABA uptake inhibitors. Design, molecular pharmacology and therapeutic aspects

    DEFF Research Database (Denmark)

    Krogsgaard-Larsen, P; Frølund, B; Frydenvang, Karla Andrea

    2000-01-01

    In the mid seventies a drug design programme using the Amanita muscaria constituent muscimol (7) as a lead structure, led to the design of guvacine (23) and (R)-nipecotic acid (24) as specific GABA uptake inhibitors and the isomeric compounds isoguvacine (10) and isonipecotic acid (11) as specific...... GABAA receptor agonists. The availability of these compounds made it possible to study the pharmacology of the GABA uptake systems and the GABAA receptors separately. Based on extensive cellular and molecular pharmacological studies using 23, 24, and a number of mono- and bicyclic analogues, it has been...... as well as glial GABA uptake in order to enhance the inhibitory effects of synaptically released GABA, or (2) selective blockade of glial GABA uptake in order to increase the amount of GABA taken up into, and subsequently released from, nerve terminals. The bicyclic compound (R)-N-Me-exo-THPO (17) has...

  10. Functional Coexpression of HSV-1 Thymidine Kinase and Green Fluorescent Protein: Implications for Noninvasive Imaging of Transgene Expression

    Directory of Open Access Journals (Sweden)

    Andreas Jacobs

    1999-06-01

    Full Text Available Current gene therapy technology is limited by the paucity of methodology for determining the location and magnitude of therapeutic transgene expression in vivo. We describe and validate a paradigm for monitoring therapeutic transgene expression by noninvasive imaging of the herpes simplex virus type 1 thymidine kinase (HSV-1-tk marker gene expression. To test proportional coexpression of therapeutic and marker genes, a model fusion gene comprising green fluorescent protein (gfp and HSV-1-tk genes was generated (tkgfp gene and assessed for the functional coexpression of the gene product, TKGFP fusion protein, in rat 9L gliosarcoma, RG2 glioma, and W256 carcinoma cells. Analysis of the TKGFP protein demonstrated that it can serve as a therapeutic gene by rendering tkgfp transduced cells sensitive to ganciclovir or as a screening marker useful for identifying transduced cells by fluorescence microscopy or fluorescence-activated cell sorting (FACS. TK and GFP activities in the TKGFP fusion protein were similar to corresponding wild-type proteins and accumulation of the HSV-1-tk-specific radiolabeled substrate, 2′-fluoro-2′-deoxy-1β-D-arabino-furanosyl-5-iodo-uracil (FIAU, in stability transduced clones correlated with gfp-fluorescence intensity over a wide range of expression levels. The tkgfp fusion gene itself may be useful in developing novel cancer gene therapy approaches. Valuable information about the efficiency of gene transfer and expression could be obtained by non-invasive imaging of tkgfp expression with FIAU and clinical imaging devices (gamma camera, positron-emission tomography [PET], single photon emission computed tomography [SPECT], and/or direct visualization of gfp expression in situ by fluorescence microscopy or endoscopy.

  11. Clinical effect of recombinant adenovirus containing thymidine kinase suicide gene in preventing postoperative recurrence of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    MENG Jian

    2017-10-01

    Full Text Available ObjectiveTo investigate the clinical effect of surgical operation combined with gene therapy in preventing postoperative recurrence of hepatocellular carcinoma (HCC. MethodsA total of 102 patients with single HCC (TNM stage 1-2, tumor diameter <10 cm who were admitted to Beijing YouAn Hospital, Capital Medical University, from July 2006 to February 2013 were enrolled, and among these patients, 60 underwent the gene therapy with recombinant adenovirus containing thymidine kinase suicide gene (ADV-TK before and after surgery (gene group and 42 underwent surgical resection alone (surgery group. The patients were followed up regularly after surgery to observe postoperative recurrence. The t-test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. The log-rank test was used for the analysis of cumulative recurrence rate, and univariate and multivariate Cox regression analyses were used to identify influencing factors for recurrence rate. ResultsThe 1-, 3-, and 5-year recurrence rates of tumor were 13.8%, 33.7%, and 47.7% in the gene group and 18.5%, 53.2%, and 69.2% in the surgery group, and there was a significant difference between the two groups (χ2=2643,P=0.041. The gene group had a significantly higher proportion of patients with pyrexia after surgery than the surgery group, and there were no significant differences in the incidence rates of other complications and length of hospital stay between the two groups. The multivariate analysis showed that gene therapy was an independent influencing factor for cumulative rumulative recurrence rate (odds ratio=2752,95 confidence interval:1164-4251,P=0038. ConclusionGene therapy combined with surgical resection can effectively reduce postoperative recurrence of tumor, and therefore, it holds promise for clinical application.

  12. Amino acid substitutions in the thymidine kinase gene of induced acyclovir-resistant herpes simplex virus type 1

    Science.gov (United States)

    Hussin, Ainulkhir; Nor, Norefrina Shafinaz Md; Ibrahim, Nazlina

    2013-11-01

    Acyclovir (ACV) is an antiviral drug of choice in healthcare setting to treat infections caused by herpes viruses, including, but not limited to genital herpes, cold sores, shingles and chicken pox. Acyclovir resistance has emerged significantly due to extensive use and misuse of this antiviral in human, especially in immunocompromised patients. However, it remains unclear about the amino acid substitutions in thymidine (TK) gene, which specifically confer the resistance-associated mutation in herpes simplex virus. Hence, acyclovir-resistant HSV-1 was selected at high concentration (2.0 - 4.5 μg/mL), and the TK-gene was subjected to sequencing and genotypic characterization. Genotypic sequences comparison was done using HSV-1 17 (GenBank Accesion no. X14112) for resistance-associated mutation determination whereas HSV-1 KOS, HSV-1 473/08 and HSV clinical isolates sequences were used for polymorphism-associated mutation. The result showed that amino acid substitutions at the non-conserved region (UKM-1: Gln34Lys, UKM-2: Arg32Ser & UKM-5: Arg32Cys) and ATP-binding site (UKM-3: Tyr53End & UKM-4: Ile54Leu) of the TK-gene. These discoveries play an important role to extend another dimension to the evolution of acyclovir-resistant HSV-1 and suggest that selection at high ACV concentration induced ACV-resistant HSV-1 evolution. These findings also expand the knowledge on the type of mutations among acyclovir-resistant HSV-1. In conclusion, HSV-1 showed multiple strategies to exhibit acyclovir resistance, including amino acid substitutions in the TK gene.

  13. Cloning of the koi herpesvirus (KHV gene encoding thymidine kinase and its use for a highly sensitive PCR based diagnosis

    Directory of Open Access Journals (Sweden)

    Gilad Oren

    2005-03-01

    Full Text Available Abstract Background Outbreaks with mass mortality among common carp Cyprinus carpio carpio and koi Cyprinus carpio koi have occurred worldwide since 1998. The herpes-like virus isolated from diseased fish is different from Herpesvirus cyprini and channel catfish virus and was accordingly designated koi herpesvirus (KHV. Diagnosis of KHV infection based on viral isolation and current PCR assays has a limited sensitivity and therefore new tools for the diagnosis of KHV infections are necessary. Results A robust and sensitive PCR assay based on a defined gene sequence of KHV was developed to improve the diagnosis of KHV infection. From a KHV genomic library, a hypothetical thymidine kinase gene (TK was identified, subcloned and expressed as a recombinant protein. Preliminary characterization of the recombinant TK showed that it has a kinase activity using dTTP but not dCTP as a substrate. A PCR assay based on primers selected from the defined DNA sequence of the TK gene was developed and resulted in a 409 bp amplified fragment. The TK based PCR assay did not amplify the DNAs of other fish herpesviruses such as Herpesvirus cyprini (CHV and the channel catfish virus (CCV. The TK based PCR assay was specific for the detection of KHV and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions. The TK based PCR was compared to previously described PCR assays and to viral culture in diseased fish and was shown to be the most sensitive method of diagnosis of KHV infection. Conclusion The TK based PCR assay developed in this work was shown to be specific for the detection of KHV. The TK based PCR assay was more sensitive for the detection of KHV than previously described PCR assays; it was as sensitive as virus isolation which is the golden standard method for KHV diagnosis and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions.

  14. Cadmium uptake by plants

    Energy Technology Data Exchange (ETDEWEB)

    Haghiri, F.

    1973-01-01

    Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cd toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.

  15. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, Mai Thanh Quynh; Stürup, Stefan; Lambert, Ian Henry

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN......(-) and H2O, respectively), were included as control samples. The results indicated that B12 derivatives delivered cisplatin to both cellular cytosol and nuclei with an efficiency of one third compared to the uptake of free cisplatin cis-[Pt(II)Cl2(NH3)2]. In addition, uptake of charged B12 derivatives...

  16. Glucose oxidation positively regulates glucose uptake and improves cardiac function recovery after myocardial reperfusion.

    Science.gov (United States)

    Li, Tingting; Xu, Jie; Qin, Xinghua; Hou, Zuoxu; Guo, Yongzheng; Liu, Zhenhua; Wu, Jianjiang; Zheng, Hong; Zhang, Xing; Gao, Feng

    2017-11-01

    Myocardial reperfusion decreases glucose oxidation and uncouples glucose oxidation from glycolysis. Therapies that increase glucose oxidation lessen myocardial ischemia-reperfusion (I/R) injury. However, the regulation of glucose uptake during reperfusion remains poorly understood. We found that glucose uptake was remarkably diminished in the myocardium following reperfusion in Sprague-Dawley rats as detected by 18 F-labeled and fluorescent-labeled glucose analogs, even though GLUT1 was upregulated by threefold and GLUT4 translocation remained unchanged compared with those of sham-treated rats. The decreased glucose uptake was accompanied by suppressed glucose oxidation. Interestingly, stimulating glucose oxidation by inhibition of pyruvate dehydrogenase kinase 4 (PDK4), a rate-limiting enzyme for glucose oxidation, increased glucose uptake and alleviated I/R injury. In vitro data in neonatal myocytes showed that PDK4 overexpression decreased glucose uptake, whereas its knockdown increased glucose uptake, suggesting that PDK4 has a role in regulating glucose uptake. Moreover, inhibition of PDK4 increased myocardial glucose uptake with concomitant enhancement of cardiac insulin sensitivity following myocardial I/R. These results showed that the suppressed glucose oxidation mediated by PDK4 contributes to the reduced glucose uptake in the myocardium following reperfusion, and enhancement of glucose uptake exerts cardioprotection. The findings suggest that stimulating glucose oxidation via PDK4 could be an efficient approach to improve recovery from myocardial I/R injury. Copyright © 2017 the American Physiological Society.

  17. Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Katebi, Samira; Esmaeili, Abolghasem, E-mail: aesmaeili@sci.ui.ac.ir; Ghaedi, Kamran

    2016-03-15

    Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

  18. The development and validation of an immunoassay for the measurement of anti-thymidine phosphorylase antibodies in mouse and dog sera.

    Science.gov (United States)

    Gasson, Charlotte; Levene, Michelle; Bax, Bridget E

    2013-01-01

    Erythrocyte encapsulated thymidine phosphorylase (EE-TP) is under development as an enzyme replacement therapy for mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), a fatal metabolic disorder resulting from an inherited deficiency of the enzyme thymidine phosphorylase. We report here the development and validation of a sensitive electrochemiluminescent (ECL) bridging immunoassay to support Good Laboratory Practice (GLP)-compliant preclinical safety studies of EE-TP in the mouse and dog. Affinity-purified rabbit anti-E. coli thymidine phosphorylase (TP) antibody was used as a calibrator standard with an effective working range of 2.5-7500 ng/mL. The minimum required dilution (MRD) for both mouse and dog sera was 1:10. The mean analytical recoveries for anti-TP antibodies spiked into serum at 70 ng/mL and 7000 ng/mL were 117.9% and 93.2%, respectively for mouse, and 112.0% and 104.3%, respectively for dog. The intra-assay precision (coefficient of variation, CV) ranged between 1.1% and 8.0% in mouse serum, and 1.9% and 2.5% in dog serum. Inter-assay precision ranged between -1.6% and 6.7% in mouse serum, and -13.0% and -2.5% in dog serum. Assay cut-point/screening cut-point correction factors were 201.37 and 44.4, respectively for mouse and dog sera. For future analysis of positive test samples, less than 37.12% (mouse) and 31.41% (dog) inhibition of the assay signal in the confirmation assay will confer anti-TP antibody specificity. Assay drift and hook effects (prozone) were not observed. The intra-assay and inter-assay accuracy for robustness were within ±20%. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Facilitation of phosphorus uptake in maize plants by mycorrhizosphere bacteria

    DEFF Research Database (Denmark)

    Battini, Fabio; Grønlund, Mette; Agnolucci, Monica

    2017-01-01

    availability of soil P. This study investigated whether biofertilizers and bioenhancers, such as arbuscular mycorrhizal fungi (AMF) and their associated bacteria could enhance growth and P uptake in maize. Plants were grown with or without mycorrhizas in compartmented pots with radioactive P tracers and were...

  20. Determinants of breast cancer screening uptake in Kurdishwomen of Iran

    Directory of Open Access Journals (Sweden)

    Nayyereh Aminisani

    2016-03-01

    Conclusion: It was found that the level of breast screening uptake was low among Kurdish women compared to those reported in the previous studies. Designing participation enhancing interventions with a specific focus on older, illiterate and post-menopausal women are recommended.

  1. Arsenic uptake and phytoremediation potential by arbuscular mycorrhizal fungi

    Science.gov (United States)

    Xinhua He; Erik Lilleskov

    2014-01-01

    Arsenic (As) contamination of soils and water is a global problem because of its impacts on ecosystems and human health. Various approaches have been attempted for As remediation, with limited success. Arbuscular mycorrhizal (AM) fungi play vital roles in the uptake of water and essential nutrients, especially phosphorus (P), and hence enhance plant performance and...

  2. Role of Genotypic Analysis of the Thymidine Kinase Gene of Herpes Simplex Virus for Determination of Neurovirulence and Resistance to Acyclovir

    OpenAIRE

    Lee, N. Y.; Tang, Y.-W.; Espy, M. J.; Kolbert, C. P.; Rys, P. N.; Mitchell, P. S.; Day, S. P.; Henry, S. L.; Persing, D. H.; Smith, T. F.

    1999-01-01

    Mutations in the thymidine kinase (TK) gene of herpes simplex virus (HSV) have been associated with resistance to acyclovir (ACY) and possible recognition of neurotropic strains. We sequenced a 335-bp segment of the TK gene to determine the frequency of mutations in HSV strains recovered from dermal, genital, and cerebrospinal fluid (CSF) specimens (n = 200; 102 HSV type 1 [HSV-1] 98 HSV-2 strains). Four polymorphic sites were detected in HSV-1 strains; C513T, A528G, C575T, and C672T. Among t...

  3. In vitro evaluation of herpes simplex virus type 1 thymidine kinase reporter system in dynamic studies of transcriptional gene regulation

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, C.-H. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Liu, R.-S. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); National Yang-Ming University Medical School and National PET/Cyclotron Center, Taipei Veterans General Hospital, Taipei 112, Taiwan (China); Wang, H.-E. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Hwang, J.-J. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Deng, W.-P. [Institute of Biomedical Material, Taipei Medical University, Taipei 112, Taiwan (China); Chen, J.-C. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Chen, F.-D. [Department of Medical Radiation Technology and Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China) and Institute of Radiological Sciences, Central Taiwan University of Science and Technology Taichung 112, Taiwan (China)]. E-mail: d49220009@ym.edu.tw

    2006-07-15

    The herpes simplex virus type 1 thymidine kinase (HSV1-TK) reporter system is being used to directly and indirectly monitor therapeutic gene expression, immune cell trafficking and protein-protein interactions in various living animals. However, the issues of HSV1-TK enzyme stability in living cells and whether this reporter system is optimal for dynamic studies of gene expression events in genetic imaging have not be addressed. The purpose of the present study was to evaluate the application of this reporter system in dynamic studies of transcriptional gene regulation. To achieve this purpose, we established two tetracycline-inducible murine sarcoma cell lines, tetracycline-turn-off HSV1-tk-expressing cell line (NG4TL4/tet-off-HSV1-tk) and tetracycline-turn-off Luc-expressing cell line (NG4TL4/tet-off-Luc), to create an artificially regulated gene expression model in vitro. The dynamic transcriptional events mediating a series of doxycycline (Dox) inductions were monitored by HSV1-TK or by the firefly luciferase reporter gene using HSV1-TK enzyme activity assay and luciferase assay, respectively. The results of dynamic gene expression studies showed that the luciferase gene is an optimal reporter gene for monitoring short-timescale, dynamic transcriptional events mediating a series of Dox inductions, whereas the HSV1-tk is not optimal to achieve this purpose. Furthermore, the enzyme half-life of HSV1-TK in NG4TL4 cells is about 35 h after cycloheximide-induced protein inhibition. On the other hand, the results of an efflux assay of [{sup 131}I] FIAU and [{sup 3}H] GCV revealed that the molecular probe phosphorylated by HSV1-TK can be trapped long term within HSV1-TK stably transformed cells. Therefore, a long half-life radionuclide is not suitable for dynamic gene expression studies. Based on these results, we suggest that the HSV1-TK reporter system is not optimal for monitoring short-timescale dynamic processes such as kinetic gene expression controlled by

  4. Thymidine kinases in archaea

    DEFF Research Database (Denmark)

    Clausen, A.R.; Matakos, A.; Sandrini, Michael

    2006-01-01

    , while none was found in Nanoarchaeum. The identified TK1s have high identity to Gram-positive bacteria TK1s. The TK1s from archaea, Gram-positive bacteria and eukaryotes share the same common ancestor, while the TK1s from Gram-negative bacteria belong to a less-related subgroup. It seems...

  5. Nitrogen Uptake in Spinach

    Science.gov (United States)

    Ramirez, J.; VanBenthem, P.

    2013-12-01

    A plant's absorption of nitrogen can be encouraged by a variety of environmental factors, especially the application of fertilizers. As a common limiting factor in plant growth, not up taking enough nitrogen can be a result of an unhealthy plant. Moreover, as farmers seek out methods to increase growth of plants, fertilizers are used as a solution to the issue of nitrogen deficiency to incorporate additional nitrogen from chemical or organic sources, by not using the right fertilizer can greatly affect the plats. The point of this research project is to determine the effect of various fertilizers on the plant growth, and to correlate the measured nitrogen, water and chlorophyll content in spinach leaves. Spinach leaves were used because they are known to quickly uptake chemicals in the environment. The spinach plants were exposed to four different growing parameters, which are referred to as control, ammonium nitrate, MiracleGro , and organic. The spinach was originally placed in nitrogen deficient soil with only 2.2x10 4 weight percent (wt. %) nitrogen. The leaves in the control group were grown in this nitrogen deficient soil without any fertilizer added. Ammomium nitrate and MiracleGro were added to the spinach in the A and MG groups, respectively, and organic chicken stool was used for the O group. By using a spectral imaging system and flame combustion techniques, the chlorophyll content can be related to the nitrogen content in the spinach leaves. In these spinach leaves, nitrogen and chlorophyll content were measured, chlorophyll is a green pigment that plays a crucial role in producing nutrients for green plants. The lack of chlorophyll will allow the plant to become susceptible to diseases, so it is extremely important that the plants have a high content of chlorophyll. The role of nitrogen in chlorophyll is very important and helps in the creation of chlorophyll; therefore it is necessary that an appropriate amount of nitrogen is added for optimal growth

  6. Actin-cytoskeleton rearrangement modulates proton-induced uptake

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Dov, Nadav [Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv (Israel); Korenstein, Rafi, E-mail: korens@post.tau.ac.il [Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv (Israel)

    2013-04-15

    Recently it has been shown that elevating proton concentration at the cell surface stimulates the formation of membrane invaginations and vesicles accompanied by an enhanced uptake of macromolecules. While the initial induction of inward membrane curvature was rationalized in terms of proton-based increase of charge asymmetry across the membrane, the mechanisms underlying vesicle formation and its scission are still unknown. In light of the critical role of actin in vesicle formation during endocytosis, the present study addresses the involvement of cytoskeletal actin in proton-induced uptake (PIU). The uptake of dextran-FITC is used as a measure for the factual fraction of inward invaginations that undergo scission from the cell's plasma membrane. Our findings show that the rate of PIU in suspended cells is constant, whereas the rate of PIU in adherent cells is gradually increased in time, saturating at the level possessed by suspended cells. This is consistent with pH induced gradual degradation of stress-fibers in adherent cells. Wortmannin and calyculin-A are able to elevate PIU by 25% in adherent cells but not in suspended cells, while cytochalasin-D, rapamycin and latrunculin-A elevate PIU both in adherent and suspended cells. However, extensive actin depolymerization by high concentrations of latrunculin-A is able to inhibit PIU. We conclude that proton-induced membrane vesiculation is restricted by the actin structural resistance to the plasma membrane bending. Nevertheless, a certain degree of cortical actin restructuring is required for the completion of the scission process. - Highlights: ► Acidification of cells' exterior enhances uptake of macromolecules by the cells. ► Disruption of actin stress fibers leads to enhancement of proton induced uptake. ► Extensive depolymerization of cellular actin attenuates proton-induced uptake.

  7. Genes of the thymidine salvage pathway: thymine-7-hydroxylase from a Rhodotorula glutinis cDNA library and iso-orotate decarboxylase from Neurospora crassa.

    Science.gov (United States)

    Smiley, Jeffrey A; Kundracik, Melisa; Landfried, Daniel A; Barnes, Vincient R; Axhemi, Armend A

    2005-05-25

    Genes for two enzymes in the thymidine salvage pathway, thymine-7-hydroxylase (THase; official name thymine dioxygenase) and iso-orotate decarboxylase (IDCase) have been isolated from fungal sources. THase was isolated from a Rhodotorula glutinis cDNA library using a degenerate oligonucleotide based on the published amino acid sequence. The coding sequence was transferred to an Escherichia coli expression system, from which recombinant THase activity was measured using 14C-labeled thymine. The THase sequence shows an almost complete avoidance of codons ending in A or T: 95.8% GC content is present in the third position of codons. A connection between this codon bias and the role of the thymidine salvage pathway in pyrimidine metabolism is proposed. The THase sequence is similar to Group I Fe+2-dependent, alphaKG-dependent dioxygenases. The R. glutinis THase gene was used to locate the probable THase genes in the sequenced genomes of Neurospora crassa and Aspergillus nidulans. The genes neighboring THase in these two genomes are similar to each other, and are similar to the mammalian 2-amino-3-carboxymuconate-6-semialdhyde decarboxylase (ACMSD), leading to their identification as IDCase genes. The N. crassa version was isolated by PCR of genomic DNA, and IDCase activity was measured in recombinant E. coli carrying this gene. A new family of decarboxylases, using similar substrates, is identified by virtue of the protein sequence similarity.

  8. Studies on yeast nucleoside triphosphate-nucleoside diphosphate transphosphorylase (nucleoside diphosphokinase). IV. Steady-state kinetic properties with thymidine nucleotides (including 3'-azido-3'-deoxythymidine analogues).

    Science.gov (United States)

    Kuby, S A; Fleming, G; Alber, T; Richardson, D; Takenaka, H; Hamada, M

    1991-01-01

    A study of the steady-state kinetics of the crystalline brewer's yeast (Saccharomyces carlsbergensis) nucleoside diphosphokinase, with the magnesium complexes of the adenine and thymidine nucleotides as reactants, has led to a postulated kinetic mechanism which proceeds through a substituted enzyme. This agrees with the earlier conclusions of Garces and Cleland [Biochemistry 1969; 8:633-640] who characterized a reaction between the magnesium complexes of the adenine and uridine nucleotides. An advantage of using thymidine nucleotides as reactants is that they permit accurate, rapid and continuous assays of the enzymatic activity in coupled-enzymatic tests. Through measurements of the initial velocities and product inhibition studies, the Michaelis constants, maximum velocities, and inhibition constants could be evaluated for the individual substrates. Competitive substrate inhibition was encountered at relatively high substrate concentrations, which also permitted an evaluation of their ability to act as 'dead-end' inhibitors. The Michaelis constants for the 3'-azido-3'-deoxythymidine (AzT) analogues were also evaluated and, although these values were only somewhat higher than those of their natural substrates, the Km's for the adenine nucleotides as paired substrates were lower and the Vmax's were drastically reduced. The pharmacological implications of these observations are touched upon and extrapolated to the cases where therapeutic doses of AzT may be employed.

  9. Bacterial production and growth rate estimation from ( sup 3 H)thymidine incorporation for attached and free-living bacteria in aquatic systems

    Energy Technology Data Exchange (ETDEWEB)

    Iriberri, J.; Unanue, M.; Ayo, B.; Barcina, I., Egea, L. (Univ. del Pais Vasco, Bilbao (Spain))

    1990-02-01

    Production and specific growth rates of attached and free-living bacteria were estimated in an oligotrophic marine system, La Salvaje Beach, Vizcaya, Spain, and in a freshwater system having a higher nutrient concentration, Butron River, Vizcaya, Spain. Production was calculated from (methyl-{sup 3}H)thymidine incorporation by estimating specific conversion factors (cells or micrograms of C produced per mole of thymidine incorporated) for attached and free-living bacteria, respectively, in each system. Conversion factors were not statistically different between attached and free-living bacteria: 6.812 {times} 10{sup 11} and 8.678 {times} 10{sup 11} {mu}g of C mol{sup {minus}1} for free-living and attached bacteria in the freshwater system, and 1.276 {times} 10{sup 11} and 1.354 {times} 10{sup 11} {mu}g of C mol{sup {minus}1} for free-living and attached bacteria in the marine system. Therefore, use of a unique conversion factor for the mixed bacterial population is well founded. However, conversion factors were higher in the freshwater system than in the marine system. This could be due to the different tropic conditions of the two systems. Free-living bacteria contributed the most to production in the two systems (85% in the marine system and 67% in the freshwater system) because of their greater contribution to total biomass. Specific growth rates calculated from production data and biomass data were similar for attached and free-living bacteria.

  10. Rapid aquatic toxicity assay using incorporation of tritiated-thymidine into sea urchin, Arbacia punctulata, embryo: evaluation of toxicant exposure procedures

    Energy Technology Data Exchange (ETDEWEB)

    Nacci, D.E.; Jackim, E.

    1985-01-01

    Toxicity of substances in seawater was measured using growth inhibition of embryonic sea urchins during a short period after fertilization. Growth of Arbacia punctulata embryos was monitored by incorporation of tritium-labeled thymidine. The paper presents a comparison of toxicant exposure procedures using the Arbacia embryo thymidine incorporation test. Toxicant exposure began before, at the time of, or after fertilization and continued for 4 h following fertilization. In addition to the eight organic chemicals tested for comparison to acute toxicity values for other species, several chemicals with embryotoxic potentials (tumor promoters and teratogens) were tested to determine differential sensitivities of exposed life-stages: unfertilized egg, fertilization, and early embryo. EC50 values for any one substance were not significantly changed by exposure modification. Toxicity values for exposures that included fertilization as well as early embryo growth were at least as sensitive as post-fertilization exposure values for all compounds tested except one. Because of technical ease and potential sensitivity, toxicant exposure that includes fertilization as well as early embryo growth (but not unfertilized egg exposure) is recommended for future testing.

  11. The antitumor effect of suicide gene therapy using Bifidobacterium infantis-mediated herpes simplex virus thymidine kinase/ganciclovir in a nude mice model of renal cell carcinoma.

    Science.gov (United States)

    Xiao, Xiao; Jin, Ren; Li, Jiang; Bei, Yu; Wei, Tang

    2014-10-01

    To confirm the effectivity of Bifidobacterium infantis-mediated herpes simplex virus thymidine kinase/ganciclovir suicide gene system on the treatment of renal cell carcinoma in nude mice and further explore the mechanisms. A B infantis thymidine kinase (B infantis-TK) suicide gene system was constructed in our previous study. Tumor-bearing nude mice were randomized into 4 groups and injected with normal saline, B infantis, B infantis/pGEX-1λT, and B infantis-TK, respectively, via tail vein, followed by intraperitoneal injection of ganciclovir. The treatment effects were evaluated by the terminal deoxynucleotidyl transferase-mediated deoxynucleotide triphosphate nick end labeling assay, quantitative reverse transcriptase polymerase chain reaction, and Western blotting. Side effects were also recorded. Compared with the other 3 treatments, the treatment with B infantis-TK resulted in a significant effective antitumor activity and stronger apoptotic response. Western blot analysis showed that the expression levels of Rel A and Bcl-xL were significantly lower, whereas those of caspase 3 and Bax were significantly higher in tumor tissues resected from group B infantis-TK, which were consistent with the quantitative reverse transcriptase-polymerase chain reaction results. The B infantis-TK/ganciclovir therapy system exhibits an effective antitumor activity by promoting tumor cell apoptosis through both the intrinsic and the extrinsic apoptotic pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Presenilin promotes dietary copper uptake.

    Directory of Open Access Journals (Sweden)

    Adam Southon

    Full Text Available Dietary copper is essential for multicellular organisms. Copper is redox active and required as a cofactor for enzymes such as the antioxidant Superoxide Dismutase 1 (SOD1. Copper dyshomeostasis has been implicated in Alzheimer's disease. Mutations in the presenilin genes encoding PS1 and PS2 are major causes of early-onset familial Alzheimer's disease. PS1 and PS2 are required for efficient copper uptake in mammalian systems. Here we demonstrate a conserved role for presenilin in dietary copper uptake in the fly Drosophila melanogaster. Ubiquitous RNA interference-mediated knockdown of the single Drosophila presenilin (PSN gene is lethal. However, PSN knockdown in the midgut produces viable flies. These flies have reduced copper levels and are more tolerant to excess dietary copper. Expression of a copper-responsive EYFP construct was also lower in the midgut of these larvae, indicative of reduced dietary copper uptake. SOD activity was reduced by midgut PSN knockdown, and these flies were sensitive to the superoxide-inducing chemical paraquat. These data support presenilin being needed for dietary copper uptake in the gut and so impacting on SOD activity and tolerance to oxidative stress. These results are consistent with previous studies of mammalian presenilins, supporting a conserved role for these proteins in mediating copper uptake.

  13. l-Methionine Placental Uptake

    Science.gov (United States)

    Araújo, João R.; Correia-Branco, Ana; Ramalho, Carla; Gonçalves, Pedro; Pinho, Maria J.; Keating, Elisa

    2013-01-01

    Our aim was to investigate the influence of gestational diabetes mellitus (GDM) and GDM-associated conditions upon the placental uptake of 14C-l-methionine (14C-l-Met). The 14C-l-Met uptake by human trophoblasts (TBs) obtained from normal pregnancies (normal trophoblast [NTB] cells) is mainly system l-type amino acid transporter 1 (LAT1 [L])-mediated, although a small contribution of system y+LAT2 is also present. Comparison of 14C-l-Met uptake by NTB and by human TBs obtained from GDM pregnancies (diabetic trophoblast [DTB] cells) reveals similar kinetics, but a contribution of systems A, LAT2, and b0+ and a greater contribution of system y+LAT1 appears to exist in DTB cells. Short-term exposure to insulin and long-term exposure to high glucose, tumor necrosis factor-α, and leptin decrease 14C-l-Met uptake in a human TB (Bewo) cell line. The effect of leptin was dependent upon phosphoinositide 3-kinase, extracellular-signal-regulated kinase 1/2 (ERK/MEK 1/2), and p38 mitogen-activated protein kinase. In conclusion, GDM does not quantitatively alter 14C-l-Met placental uptake, although it changes the nature of transporters involved in that process. PMID:23653387

  14. Unlabelled iododeoxyuridine increases the rate of uptake of [{sup 125}I]iododeoxyuridine in human xenografted glioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Dupertuis, Yves M. [Division of Nuclear Medicine, University Hospital of Geneva (Switzerland); Clinical Nutrition, University Hospital of Geneva (Switzerland); Xiao, Wei-Hong; Slosman, Daniel O. [Division of Nuclear Medicine, University Hospital of Geneva (Switzerland); Tribolet, N. de [Division of Neurosurgery, University Hospital of Geneva (Switzerland); Pichard, Claude [Clinical Nutrition, University Hospital of Geneva (Switzerland); Bischof Delaloye, Angelika [Department of Nuclear Medicine, University Hospital of Lausanne (Switzerland); Buchegger, Franz [Division of Nuclear Medicine, University Hospital of Geneva (Switzerland); Department of Nuclear Medicine, University Hospital of Lausanne (Switzerland)

    2002-04-01

    5-Iodo-2'-deoxyuridine (IdUrd), a thymidine (TdR) analogue, can be radiolabelled with iodine-125, an Auger radiation emitter, to provoke double-strand breaks once incorporated into DNA of cancer cells. We have previously shown that co-incubation of [{sup 125}I]IdUrd with unlabelled IdUrd provided an additive cytotoxicity in two human glioblastoma cell lines. This observation was unexpectedly correlated with an increase in the rate of DNA incorporation of [{sup 125}I]IdUrd. Here, we further evaluated the effects of unlabelled IdUrd on the uptake of [{sup 125}I]IdUrd in vitro and in vivo in mice xenografted with three human glioblastoma lines. The results showed that, in these three glioblastoma lines, unlabelled IdUrd increased the rate of uptake of [{sup 125}I]IdUrd in vitro by 2- to 4.4-fold and in vivo by 1.5- to 2.8-fold. The rate of uptake of [{sup 125}I]IdUrd in normal rapidly dividing tissues was also increased by 1.3- to 2.8-fold. TdR completely blocked [{sup 125}I]IdUrd uptake in tumours and tissues. Analogues of IdUrd, such as deoxyuridine and 5-iodo-1,3-dimethyuracil, did not reproduce the effect of IdUrd on the uptake of [{sup 125}I]IdUrd, suggesting that it is not related to protection against [{sup 125}I]IdUrd degradation. It is concluded that combined administration of unlabelled IdUrd may improve the use of radiolabelled IdUrd for cancer diagnosis or therapy. (orig.)

  15. Light and dark reactions of the uptake hydrogenase in anabaena 7120.

    Science.gov (United States)

    Houchins, J P; Burris, R H

    1981-09-01

    Reactions of the uptake hydrogenase from Anabaena 7120 (A.T.C.C. 27893, Nostoc muscorum) were examined in whole filaments, isolated heterocysts, and membrane particles. Whole filaments or isolated heterocysts that contained nitrogenase consumed H(2) in the presence of C(2)H(2) or N(2) in a light-dependent reaction. If nitrogenase was inactivated by O(2) shock, filaments catalyzed H(2) uptake to an unidentified endogenous acceptor in the light. Addition of NO(3) (-) or NO(2) (-) enhanced these rates. Isolated heterocysts consumed H(2) in the dark in the presence of electron acceptors with positive midpoint potentials, and these reactions were not enhanced by light. With acceptors of negative midpoint potential, significant light enhancement of H(2) uptake occurred. Maximum rates of light-dependent uptake were approximately 25% of the maximum dark rates observed. Membrane particles prepared from isolated heterocysts showed similar specificity for electron acceptors. These particles catalyzed a cyanide-sensitive oxyhydrogen reaction that was inactivated by O(2) at O(2) concentrations above 2%. Light-dependent H(2) uptake to low potential acceptors by these particles was inhibited by dibromothymoquinone but was insensitive to cyanide. In the presence of O(2), light-dependent H(2) uptake occurred simultaneously with the oxyhydrogen reaction. The pH optima for both types of H(2) uptake were near 7.0. These results further clarify the role of uptake hydrogenase in donating electrons to both the photosynthetic and respiratory electron transport chains of Anabaena.

  16. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with {sup 125}I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morgenroth, Agnieszka, E-mail: amorgenroth@ukaachen.de [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Mottaghy, Felix M. [Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Reske, Sven N. [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany)

    2011-10-15

    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue {sup 125}I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([{sup 125}I]ITdU). Methods: Cellular uptake and DNA incorporation of [{sup 125}I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [{sup 125}I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [{sup 125}I]ITdU was proven by clonogenic assay. Results: [{sup 125}I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [{sup 125}I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [{sup 125}I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [{sup 125}I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a

  17. Expression of brain derived neurotrophic factor, activity-regulated cytoskeleton protein mRNA, and enhancement of adult hippocampal neurogenesis in rats after sub-chronic and chronic treatment with the triple monoamine re-uptake inhibitor tesofensine

    DEFF Research Database (Denmark)

    Larsen, Marianne Hald; Rosenbrock, Holger; Sams-Dodd, Frank

    2007-01-01

    D-immunoreactivity. We find that chronic, but not sub-chronic treatment with Tesofensine increases BDNF mRNA in the CA3 region of the hippocampus (35%), and Arc mRNA in the CA1 of the hippocampus (65%). Furthermore, the number of Ki-67- and neuroD-positive cells increased after chronic, but not sub-chronic treatment....... This study shows that Tesofensine enhances hippocampal gene expression and new cell formation indicative for an antidepressant potential of this novel drug substance....

  18. Coupling of methylmercury uptake with respiration and water pumping in freshwater tilapia Oreochromis niloticus.

    Science.gov (United States)

    Wang, Rui; Wong, Ming-Hung; Wang, Wen-Xiong

    2011-09-01

    The relationships among the uptake of toxic methylmercury (MeHg) and two important fish physiological processes-respiration and water pumping--in the Nile tilapia (Oreochromis niloticus) were explored in the present study. Coupled radiotracer and respirometric techniques were applied to measure simultaneously the uptake rates of MeHg, water, and oxygen under various environmental conditions (temperature, dissolved oxygen level, and water flow). A higher temperature enhanced MeHg influx and the oxygen consumption rate but had no effect on the water uptake, indicating the influence of metabolism on MeHg uptake. The fish showed a high tolerance to hypoxia, and the oxygen consumption rate was not affected until the dissolved oxygen concentration decreased to extremely low levels (below 1 mg/L). The MeHg and water uptake rates increased simultaneously as the dissolved oxygen level decreased, suggesting the coupling of water flux and MeHg uptake. The influence of fish swimming performance on MeHg uptake was also investigated for the first time. Rapidly swimming fish showed significantly higher uptake rates of MeHg, water, and oxygen, confirming the coupling relationships among respiration, water pumping, and metal uptake. Moreover, these results support that MeHg uptake is a rate-limiting process involving energy. Our study demonstrates the importance of physiological processes in understanding mercury bioaccumulation in fluctuating aquatic environments. Copyright © 2011 SETAC.

  19. Uptake and translocation of imidacloprid, clothianidin and flupyradifurone in seed-treated soybeans.

    Science.gov (United States)

    Stamm, Mitchell D; Heng-Moss, Tiffany M; Baxendale, Frederick P; Siegfried, Blair D; Blankenship, Erin E; Nauen, Ralf

    2016-06-01

    Seed treatment insecticides have become a popular management option for early-season insect control. This study investigated the total uptake and translocation of seed-applied [(14) C]imidacloprid, [(14) C]clothianidin and [(14) C]flupyradifurone into different plant parts in three soybean vegetative stages (VC, V1 and V2). The effects of soil moisture stress on insecticide uptake and translocation were also assessed among treatments. We hypothesized that (1) uptake and translocation would be different among the insecticides owing to differences in water solubility, and (2) moisture stress would increase insecticide uptake and translocation. Uptake and translocation did not follow a clear trend in the three vegetative stages. Initially, flupyradifurone uptake was greater than clothianidin uptake in VC soybeans. In V1 soybeans, differences in uptake among the three insecticides were not apparent and unaffected by soil moisture stress. Clothianidin was negatively affected by soil moisture stress in V2 soybeans, while imidacloprid and flupyradifurone were unaffected. Specifically, soil moisture stress had a positive effect on the distribution of flupyradifurone in leaves. This was not observed with the neonicotinoids. This study enhances our understanding of the uptake and distribution of insecticides used as seed treatments in soybean. The uptake and translocation of these insecticides differed in response to soil moisture stress. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Octreotide Uptake in Parathyroid Adenoma

    Directory of Open Access Journals (Sweden)

    Seyhan Karaçavuş

    2012-08-01

    Full Text Available The patient with a history of bone pain and muscle weakness, was thought to have oncogenic osteomalacia as a result of biochemical investigations and directed to Nuclear Medicine Department for a whole-body bone scintigraphy and 111In-octreotide scintigraphy. There was no focal pathologic tracer uptake, but generalized marked increase in skeletal uptake on bone scintigraphy. Octreotide scintigraphy showed accumulation of octreotide in the region of the left lobe of the thyroid gland in the neck. Thereafter, parathyroid scintigraphy was performed with technetium-99m labeled metroxy-isobutyl-isonitryl (99mTc-MIB and MIBI scan demonstrated radiotracer uptake at the same location with octreotide scintigraphy. The patient underwent left inferior parathyroidectomy and histopathology confirmed a parathyroid adenoma. Somatostatin receptor positive parathyroid adenoma may show octreotide uptake. Octreotide scintigraphy may be promising and indicate a possibility of using somatostatin analogues for the medical treatment of somatostatin receptor positive parathyroid tumors. (MIRT 2012;21:77-79

  1. Limited uptake of the cyanobacterial toxin cylindrospermopsin by Vero cells.

    Science.gov (United States)

    Froscio, S M; Cannon, E; Lau, H M; Humpage, A R

    2009-11-01

    Cylindrospermopsin (CYN) is a cyanobacterial toxin increasingly found in drinking water sources worldwide. Toxicity studies have shown CYN can induce effects in a range of different cell types with primary hepatocytes consistently shown to be the most sensitive cellular model. How CYN enters the intracellular environment is not clear, although the size and hydrophilic nature of the toxin suggest it would not readily cross a lipid bilayer. In this study, a Vero cell line expressing green fluorescent protein (GFP) was used to monitor for CYN uptake based on the toxin's potent effects on protein synthesis. Effects on the GFP signal were compared with inhibitors cycloheximide (CHEX) and emetine. While CYN potency was demonstrated in a cell-free system (CYN>CHEX>emetine) it was considerably reduced in the Vero-GFP cell model (CHEX, emetine>CYN). In contrast to other inhibitors, CYN effects on GFP signal increased 6 fold over 4-24 h incubation indicating slow, progressive uptake of the toxin. Confirming that the uptake process is not energy dependent CYN entry also occurred at 4 degrees C, while competition experiments excluded the uracil nucleobase transporter system as potential mechanism for CYN uptake. Dilution of media enhanced CYN uptake by Vero-GFP cells although mechanism by which this occurred is unknown.

  2. Facilitation of phosphorus uptake in maize plants by mycorrhizosphere bacteria.

    Science.gov (United States)

    Battini, Fabio; Grønlund, Mette; Agnolucci, Monica; Giovannetti, Manuela; Jakobsen, Iver

    2017-07-05

    A major challenge for agriculture is to provide sufficient plant nutrients such as phosphorus (P) to meet the global food demand. The sufficiency of P is a concern because of it's essential role in plant growth, the finite availability of P-rock for fertilizer production and the poor plant availability of soil P. This study investigated whether biofertilizers and bioenhancers, such as arbuscular mycorrhizal fungi (AMF) and their associated bacteria could enhance growth and P uptake in maize. Plants were grown with or without mycorrhizas in compartmented pots with radioactive P tracers and were inoculated with each of 10 selected bacteria isolated from AMF spores. Root colonization by AMF produced large plant growth responses, while seven bacterial strains further facilitated root growth and P uptake by promoting the development of AMF extraradical mycelium. Among the tested strains, Streptomyces sp. W94 produced the largest increases in uptake and translocation of 33 P, while Streptomyces sp. W77 highly enhanced hyphal length specific uptake of 33 P. The positive relationship between AMF-mediated P absorption and shoot P content was significantly influenced by the bacteria inoculants and such results emphasize the potential importance of managing both AMF and their microbiota for improving P acquisition by crops.

  3. Synthesis and Biological Evaluation of a New Acyclic Pyrimidine Derivative as a Probe for Imaging Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression

    Directory of Open Access Journals (Sweden)

    Simon M. Ametamey

    2013-07-01

    Full Text Available With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk gene expression by means of positron emission tomography (PET, a novel [18F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethylbutyl side chain at N-1 (HHB-5-[18F]FEP was prepared and evaluated as a potential PET probe. Unlabeled reference compound, HHB-5-FEP, was synthesized via a five-step reaction sequence starting from 5-(2-acetoxyethyl-4-methoxypyrimidin-2-one. The radiosynthesis of HHB-[18F]-FEP was accomplished by nucleophilic radiofluorination of a tosylate precursor using [18F]fluoride-cryptate complex in 45% ± 4 (n = 4 radiochemical yields and high purity (>99%. The biological evaluation indicated the feasibility of using HHB-5-[18F]FEP as a PET radiotracer for monitoring HSV1-tk expression in vivo.

  4. Nitrogen uptake kinetics of freshly isolated zooxanthellae

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Rajkumar, R.

    Zooxanthellae freshly isolated from the coral host Pocillopora damicornis exhibited substrate-saturable uptake kinetics for ammonium, nitrate and urea. Maximum uptake velocity for ammonium [10.1 nmol. ( mu chl-a)./1h/1] was greater than...

  5. Intravenous Administration Is an Effective and Safe Route for Cancer Gene Therapy Using the Bifidobacterium-Mediated Recombinant HSV-1 Thymidine Kinase and Ganciclovir

    Directory of Open Access Journals (Sweden)

    Huicong Zhou

    2016-06-01

    Full Text Available The herpes simplex virus thymidine kinase/ganciclovir (HSV TK/GCV system is one of the best studied cancer suicide gene therapy systems. Our previous study showed that caspase 3 expression was upregulated and bladder tumor growth was significantly reduced in rats treated with a combination of Bifidobacterium (BF and HSV TK/GCV (BF-rTK/GCV. However, it was raised whether the BF-mediated recombinant thymidine kinase combined with ganciclovir (BF-rTK/GCV was safe to administer via venous for cancer gene therapy. To answer this question, the antitumor effects of BF-rTK/GCV were mainly evaluated in a xenograft nude mouse model bearing MKN-45 gastric tumor cells. The immune response, including analysis of cytokine profiles, was analyzed to evaluate the safety of intramuscular and intravenous injection of BF-rTK in BALB/c mice. The results suggested that gastric tumor growth was significantly inhibited in vivo by BF-rTK/GCV. However, the BF-rTK/GCV had no effect on mouse body weight, indicating that the treatment was safe for the host. The results of cytokine profile analysis indicated that intravenous injection of a low dose of BF-rTK resulted in a weaker cytokine response than that obtained with intramuscular injection. Furthermore, immunohistochemical analysis showed that intravenous administration did not affect the expression of immune-associated TLR2 and TLR4. Finally, the BF-rTK/GCV inhibited vascular endothelial growth factor (VEGF expression in mouse model, which is helpful for inhibiting of tumor angiogenesis. That meant intravenous administration of BF-rTK/GCV was an effective and safe way for cancer gene therapy.

  6. Intravenous Administration Is an Effective and Safe Route for Cancer Gene Therapy Using the Bifidobacterium-Mediated Recombinant HSV-1 Thymidine Kinase and Ganciclovir.

    Science.gov (United States)

    Zhou, Huicong; He, Zhiliang; Wang, Changdong; Xie, Tingting; Liu, Lin; Liu, Chuanyang; Song, Fangzhou; Ma, Yongping

    2016-06-06

    The herpes simplex virus thymidine kinase/ganciclovir (HSV TK/GCV) system is one of the best studied cancer suicide gene therapy systems. Our previous study showed that caspase 3 expression was upregulated and bladder tumor growth was significantly reduced in rats treated with a combination of Bifidobacterium (BF) and HSV TK/GCV (BF-rTK/GCV). However, it was raised whether the BF-mediated recombinant thymidine kinase combined with ganciclovir (BF-rTK/GCV) was safe to administer via venous for cancer gene therapy. To answer this question, the antitumor effects of BF-rTK/GCV were mainly evaluated in a xenograft nude mouse model bearing MKN-45 gastric tumor cells. The immune response, including analysis of cytokine profiles, was analyzed to evaluate the safety of intramuscular and intravenous injection of BF-rTK in BALB/c mice. The results suggested that gastric tumor growth was significantly inhibited in vivo by BF-rTK/GCV. However, the BF-rTK/GCV had no effect on mouse body weight, indicating that the treatment was safe for the host. The results of cytokine profile analysis indicated that intravenous injection of a low dose of BF-rTK resulted in a weaker cytokine response than that obtained with intramuscular injection. Furthermore, immunohistochemical analysis showed that intravenous administration did not affect the expression of immune-associated TLR2 and TLR4. Finally, the BF-rTK/GCV inhibited vascular endothelial growth factor (VEGF) expression in mouse model, which is helpful for inhibiting of tumor angiogenesis. That meant intravenous administration of BF-rTK/GCV was an effective and safe way for cancer gene therapy.

  7. Characterization of clinically isolated thymidine-dependent small-colony variants of Escherichia coli producing extended-spectrum β-lactamase.

    Science.gov (United States)

    Negishi, Tatsuya; Matsumoto, Takehisa; Horiuchi, Kazuki; Kasuga, Eriko; Natori, Tatsuya; Matsuoka, Mina; Ogiwara, Naoko; Sugano, Mitsutoshi; Uehara, Takeshi; Nagano, Noriyuki; Honda, Takayuki

    2018-01-01

    Thymidine-dependent small-colony variants (TD-SCVs) are difficult to detect or test for antimicrobial susceptibility. We investigated the characteristics of clonal TD-SCVs of Escherichia coli, both with and without blaCTX-M-3, isolated from a patient. Mutation in the thyA gene was analysed by sequencing, and morphological abnormalities in the colonies and cells of the isolates were examined. Additionally, conjugational transfer experiments were performed to prove the horizontal transferability of plasmids harbouring resistance genes. The TD-SCVs contained a single nucleotide substitution in the thyA gene, c.62G>A, corresponding to p.Arg21His. Morphologically, their colonies were more translucent and flattened than those of the wild-type strain. In addition, cells of the TD-SCVs were swollen and elongated, sometimes with abnormal and incomplete divisions; a large amount of cell debris was also observed. Changing c.62G>A back to the wild-type sequence reversed these abnormalities. Conjugational transfer experiments showed that the TD-SCV of E. coli with blaCTX-M-3 failed to transfer blaCTX-M-3 to E. coli CSH2. However, the TD-SCV of E. coli without blaCTX-M-3 experimentally received the plasmid encoding blaSHV-18 from Klebsiella pneumoniae ATCC 700603 and transferred it to E. coli CSH2. Mutation in the thyA gene causes morphological abnormalities in the colonies and cells of E. coli, as well as inducing thymidine auxotrophy. In addition, TD-SCVs horizontally transmit plasmids encoding resistance genes. It is important to detect TD-SCVs based on their characteristics because they serve as reservoirs of transferable antibiotic resistance plasmids.

  8. Arsenic uptake in bacterial calcite

    Science.gov (United States)

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03 Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  9. Arsenic uptake in bacterial calcite

    Energy Technology Data Exchange (ETDEWEB)

    Catelani, Tiziano; Perito, Brunella; Bellucci, Francesco; Lee, Sang Soo; Fenter, Paul; Newville, Matthew G.; Rimondi, Valentina; Pratesi, Giovanni; Costagliola, Pilario

    2018-02-01

    Bio-mediated processes for arsenic (As) uptake in calcite were investigated by means of X-ray Diffraction (XRD) and Xray Absorption Spectroscopy (XAS) coupled with X-ray Fluorescence measurements. The environmental bacterial strain Bacillus licheniformis BD5, sampled at the Bullicame Hot Springs (Viterbo, Central Italy), was used to synthesize calcite from As-enriched growth media. Both liquid and solid cultures were applied to simulate planktonic and biofilm community environments, respectively. Bacterial calcite samples cultured in liquid media had an As enrichment factor (Kd) 50 times higher than that from solid media. The XRD analysis revealed an elongation of the crystal lattice along the c axis (by 0.03Å) for biogenic calcite, which likely resulted from the substitution of larger arsenate for carbonate in the crystal. The XAS data also showed a clear difference in the oxidation state of sorbed As between bacterial and abiotic calcite. Abiotic chemical processes yielded predominantly As(V) uptake whereas bacterial precipitation processes led to the uptake of both As(III) and As(V). The presence of As(III) in bacterial calcite is proposed to result from subsequent reduction of arsenate to arsenite by bacterial activities. To the best of our knowledge, this is the first experimental observation of the incorporation of As(III) in the calcite crystal lattice, revealing a critical role of biochemical processes for the As cycling in nature.

  10. Quantitative understanding of nanoparticle uptake in watermelon plants

    OpenAIRE

    Ramesh Raliya; Christina Franke; Sanmathi Chavalmane; Remya Nair; Nathan Reed; Pratim Biswas

    2016-01-01

    The use of agrochemical-nutrient fertilizers has come under scrutiny in recent years due to concerns that they damage the ecosystem and endanger public health. Nanotechnology offers many possible interventions to mitigate these risks by use of nanofertilizers, nanopesticides, and nanosensors; and concurrently increases profitability, yields, and sustainability within the agricultural industry. Aerosol based foliar delivery of nanoparticles may help to enhance nanoparticle uptake and reduce en...

  11. Radioactive contamination of the marine environment: Uptake and distribution of3H in Dunaliella bioculata

    Science.gov (United States)

    Strack, S.; Bonotto, S.; Kirchmann, R.

    1980-03-01

    The marine flagellate Dunaliella bioculata, which is easily cultivated under laboratory conditions, is a suitable organism for assessing the importance of the radioactive contamination by3H bound to organic molecules. We have studied the uptake of the following tritiated precursors: thymidine-methyl-3H, adenine-2-3H, uridine-5-3H, l-leucine-4-3H, glycine-2-3H, l-arginine-3.4-3H, 1-aspartic acid-2. 3-3H, 1-phenylalanine-2.3-3H, D-glucose-2-3H and D-glucose-6-3H. Under the experimental conditions (2000 lux; incubation time 30 min), all tritiated molecules are taken up by D. bioculata. Their intracellular concentration may reach that of the external medium. However, leucine and adenine accumulate in the algae: their respective concentrations are 10 and 100 times higher than in the culture medium. The molecular distribution of3H has been studied by various biochemical techniques and by sieve chromatography on sepharose 4B. It has been found that more l-leucine-4-3H is incorporated into acid and acetone soluble substances than into proteins. Adenine-2-3H is mainly incorporated into macromolecules of biological significance (RNA, DNA). CsCl gradient centrifugation has shown that the total DNA of Dunaliella is constituted by a major (ϖ=1.707 g/cm3) and by a minor (ϖ=1.693 g/cm3) component.

  12. Mechanisms of hepatic methylmercury uptake

    Energy Technology Data Exchange (ETDEWEB)

    Ballatori, N.; Truong, A.T. [Univ. of Rochester School of Medicine, NY (United States)

    1995-11-01

    The mechanism by which methylmercury is cleared from hepatic portal blood was examined in isolated rat livers perfused single-pass with Krebs-Henseleit buffer. [{sup 203}Hg]Methylmercury (0.24-24 {mu}M) was infused over a 30-min interval, followed by a 30-min washout, as a complex with the endogenous ligands L-cysteine (CH{sub 3}Hg-L-cys), gluthathione (CH{sub 3}Hg-DTT), chloride (CH{sub 3}HgCl), and the D-enantiomer of cysteine (CH{sub 3}Hg-D-cys). The sulfhydryl-containing compounds were added at a 10-fold molar excess. When administered as the albumin complex, only a small fraction of the [{sup 203}Hg]methylmercury was cleared from perfusate ({approximately}8%) and excreted into bile (0.7%). Hepatic uptake and biliary excretion of methylmercury was considerably higher for the other complexes. For the dithiothreitol complex, hepatic extraction of methylmercury was nearly complete during single-pass perfusion. A comparison of hepatic removal of increasing doses of CH{sub 3}Hg-L-cys and CH{sub 3}Hg-L-cys and CH{sub 3}-D-cys revealed little difference. Moreover, the fraction of methylmercury removed was similar at concentrations of 0.24, 2.4, and 24 {mu}M, indicating no saturability of uptake in this dose range. Methylmercury was not hepatotoxic at concentrations up to 24 {mu}M if administered as a mercaptide; however, the chloride complex (CH{sub 3}HgCl) produced cholestasis and an increase in perfusion pressure at a concentration of only 0.24 {mu}m. These findings indicate that hepatic methylmercury uptake and toxicity are dependent on the chemical form in blood plasma. Uptake was faster when methylmercury was present as a cysteine or glutathione complex, as compared to the albumin complex; however, the lack of steroselectivity indicates that the uptake process may be relatively unselective.

  13. Herpes simplex virus thymidine kinase imaging in mice with (1-(2'-deoxy-2'-[{sup 18}F]fluoro-1-{beta}-D-arabinofuranosyl)-5-iodouracil) and metabolite (1-(2'-deoxy-2'-[{sup 18}F]fluoro-1-{beta}-D-arabinofuranosyl)-5-uracil)

    Energy Technology Data Exchange (ETDEWEB)

    Nimmagadda, Sridhar; Lawhorn-Crews, Jawana M.; Shields, Anthony F. [Wayne State University, Karmanos Cancer Institute, Detroit, MI (United States); Wayne State University, Department of Medicine, Detroit, MI (United States); Mangner, Thomas J. [Wayne State University, Karmanos Cancer Institute, Detroit, MI (United States); Wayne State University, Department of Radiology, Detroit, MI (United States); Haberkorn, Uwe [University of Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany)

    2009-12-15

    FIAU, (1-(2{sup '}-deoxy-2{sup '}-fluoro-1-{beta}-D-arabinofuranosyl)-5-iodouracil) has been used as a substrate for herpes simplex virus thymidine kinases (HSV-TK and HSV-tk, for protein and gene expression, respectively) and other bacterial and viral thymidine kinases for noninvasive imaging applications. Previous studies have reported the formation of a de-iodinated metabolite of {sup 18}F-FIAU. This study reports the dynamic tumor uptake, biodistribution, and metabolite contribution to the activity of {sup 18}F-FIAU seen in HSV-tk gene expressing tumors and compares the distribution properties with its de-iodinated metabolite {sup 18}F-FAU. CD-1 nu/nu mice with subcutaneous MH3924A and MH3924A-stb-tk+ xenografts on opposite flanks were used for the biodistribution and imaging studies. Mice were injected IV with either {sup 18}F-FIAU or {sup 18}F-FAU. Mice underwent dynamic imaging with each tracer for 65 min followed by additional static imaging up to 150 min post-injection for some animals. Animals were sacrificed at 60 or 150 min post-injection. Samples of blood and tissue were collected for biodistribution and metabolite analysis. Regions of interest were drawn over the images obtained from both tumors to calculate the time-activity curves. Biodistribution and imaging studies showed the highest uptake of {sup 18}F-FIAU in the MH3924A-stb-tk+ tumors. Dynamic imaging studies revealed a continuous accumulation of {sup 18}F-FIAU in HSV-TK expressing tumors over 60 min. The mean biodistribution values (SUV {+-} SE) for MH3924A-stb-tk+ were 2.07 {+-} 0.40 and 6.15 {+-} 1.58 and that of MH3924A tumors were 0.19 {+-} 0.07 and 0.47 {+-} 0.06 at 60 and 150 min, respectively. In {sup 18}F-FIAU injected mice, at 60 min nearly 63% of blood activity was present as its metabolite {sup 18}F-FAU. Imaging and biodistribution studies with {sup 18}F-FAU demonstrated no specific accumulation in MH3924A-stb-tk+ tumors and SUVs for both the tumors were similar to those

  14. Cysteine- and glutathione-mediated uptake of lead and cadmium into Zea mays and Brassica napus roots

    Energy Technology Data Exchange (ETDEWEB)

    Vadas, Timothy M., E-mail: tvadas@umbc.ed [Department of Biological and Environmental Engineering, Cornell University, 320 Riley-Robb Hall, Ithaca, NY 14853 (United States); Ahner, Beth A., E-mail: baa7@cornell.ed [Department of Biological and Environmental Engineering, Cornell University, 320 Riley-Robb Hall, Ithaca, NY 14853 (United States)

    2009-08-15

    This study examines a new mechanism for the uptake of Pb and Cd into Brassica napus and Zea mays roots. During hydroponic experiments, the uptake of Pb and Cd was enhanced in the presence of cysteine and glutathione, whereas no or very low uptake was observed in EDTA and penicillamine controls. Uptake rates were also enhanced after pre-exposure to cysteine or glutathione and inhibited in the presence of vanadate, suggesting a biological mechanism of uptake. Increasing concentrations of glutathione in solution resulted in decreasing Pb uptake rates, indicating competition for transport between free-glutathione and Pb-glutathione species. Pb uptake in the presence of increasing cysteine concentrations resulted in decreased uptake initially but linearly increasing uptake at higher concentrations. Experimentation showed concentration dependent Pb uptake rates. We speculate that there are specific transporters for these thiol ligands and describe what barriers remain for application of this novel transport mechanism in chelator-assisted phytoremediation. - Cysteine and glutathione mediate the transport of lead and cadmium into plant roots.

  15. Identification of multiple cellular uptake pathways of polystyrene nanoparticles and factors affecting the uptake: relevance for drug delivery systems.

    Science.gov (United States)

    Firdessa, Rebuma; Oelschlaeger, Tobias A; Moll, Heidrun

    2014-01-01

    Nanoparticles may address challenges by human diseases through improving diagnosis, vaccination and treatment. The uptake mechanism regulates the type of threat a particle poses on the host cells and how a cell responds to it. Hence, understanding the uptake mechanisms and cellular interactions of nanoparticles at the cellular and subcellular level is a prerequisite for their effective biomedical applications. The present study shows the uptake mechanisms of polystyrene nanoparticles and factors affecting their uptake in bone marrow-derived macrophages, 293T kidney epithelial cells and L929 fibroblasts. Labeling with the endocytic marker FM4-64 and transmission electron microscopy studies show that the nanoparticles were internalized rapidly via endocytosis and accumulated in intracellular vesicles. Soon after their internalizations, nanoparticles trafficked to organelles with acidic pH. Analysis of the ultrastructural morphology of the plasma membrane invaginations or extravasations provides clear evidence for the involvement of several uptake routes in parallel to internalize a given type of nanoparticles by mammalian cells, highlighting the complexity of the nanoparticle-cell interactions. Blocking the specific endocytic pathways by different pharmacological inhibitors shows similar outcomes. The potential to take up nanoparticles varies highly among different cell types in a particle sizes-, time- and energy-dependent manner. Furthermore, infection and the activation status of bone marrow-derived macrophages significantly affect the uptake potential of the cells, indicating the need to understand the diseases' pathogenesis to establish effective and rational drug-delivery systems. This study enhances our understanding of the application of nanotechnology in biomedical sciences. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Putrescine Uptake in Saintpaulia Petals 1

    Science.gov (United States)

    Bagni, Nello; Pistocchi, Rossella

    1985-01-01

    Putrescine uptake and the kinetics of this uptake were studied in petals of Saintpaulia ionantha Wendl. Uptake experiments of [3H] or [14C] putrescine were done on single petals at room temperature at various pH values. The results show that putrescine uptake occurs against a concentration gradient at low external putrescine concentration (0.5-100 micromolar) and follows a concentration gradient at higher external putrescine concentrations (100 micromolar to 100 millimolar). 2,4-Dinitrophenol and carbonylcyanide-m-chlorophenylhydrazone, two uncouplers, had no effect on putrescine uptake. Uptake rates were constant for 2 hours, reaching a maximum after 3 to 4 hours. Putrescine uptake depended markedly on the external pH and two maxima were observed: at low external concentrations of putrescine, the optimum was at pH 5 to 5.5; at higher concentrations the optimum was at pH 8. PMID:16664065

  17. DNA Uptake by Transformable Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, Sanford A.

    1999-03-31

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  18. DNA UPTAKE BY TRANSFORMABLE BACTERIA

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    1999-09-07

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  19. Polyamine Uptake in Carrot Cell Cultures 1

    Science.gov (United States)

    Pistocchi, Rossella; Bagni, Nello; Creus, José A.

    1987-01-01

    Putrescine and spermidine uptake into carrot (Daucus carota L.) cells in culture was studied. The time course of uptake showed that the two polyamines were very quickly transported into the cells, reaching a maximum absorption within 1 minute. Increasing external polyamine concentrations up to 100 millimolar showed the existence of a biphasic system with different affinities at low and high polyamine concentrations. The cellular localization of absorbed polyamines was such that a greater amount of putrescine was present in the cytoplasmic soluble fraction, while spermidine was mostly present in cell walls. The absorbed polyamines were released into the medium in the presence of increasing external concentrations of the corresponding polyamine or Ca2+. The effects of Ca2+ were different for putrescine and spermidine; putrescine uptake was slightly stimulated by 10 micromolar Ca2+ and inhibited by higher concentrations, while for spermidine uptake there was an increasing stimulation in the Ca2+ concentration range between 10 micromolar and 1 millimolar. La3+ nullified the stimulatory effect of 10 micromolar Ca2+ on putrescine uptake and that of 1 millimolar Ca2+ on spermidine uptake. La3+ at 0.5 to 1 millimolar markedly inhibited the uptake of both polyamines, suggesting that it interferes with the sites of polyamine uptake. Putrescine uptake was affected to a lesser extent by metabolic inhibitors than was spermidine uptake. It is proposed that the entry of polyamines into the cells is driven by the transmembrane electrical gradient, with a possible antiport mechanism between external and internal polyamine molecule. PMID:16665446

  20. Influenza vaccination uptake among Victorian healthcare workers: evaluating the success of a statewide program.

    Science.gov (United States)

    Johnson, Sandra A; Bennett, Noleen; Bull, Ann L; Richards, Michael J; Worth, Leon J

    2016-06-01

    Annual influenza vaccination is recommended for all Australian healthcare workers (HCWs). In 2014, a target vaccination uptake of 75% was set for Victorian healthcare facilities. This study aimed to determine the 2014 uptake, describe trends over time and propose an enhanced reporting framework. Annual data submitted to the Victorian Healthcare Associated Infection Surveillance System (VICNISS) regarding HCW influenza were evaluated for 2005-2014. Faculty uptake - the number of vaccinations administered divided by total number of staff employed - was reported as a statewide aggregate and stratified by facility size (number of staff employed). In 2014, 78,885 HCWs were vaccinated across 93 healthcare facilities, corresponding to an overall uptake of 72.2%. During 2005-2014, small facilities (healthcare facility size categories, the highest uptake was observed in 2014. Influenza vaccination uptake in HCWs has successfully been introduced as a performance indicator in Victorian healthcare facilities and a peak uptake was reported in 2014. Varied trends are evident when uptake is stratified by number of employed HCWs, providing a feasible and meaningful method for benchmarking. © 2015 Public Health Association of Australia.

  1. Polyamine Uptake, Kinetics, and Competition among Polyamines and between Polyamines and Inorganic Cations.

    Science.gov (United States)

    Pistocchi, R; Bagni, N; Creus, J A

    1986-02-01

    Polyamine uptake, the kinetics of this uptake, and the competition among polyamines and between polyamines and inorganic cations were studied in petals of Saintpaulia ionantha Wendl. Uptake experiments using (14)C-labeled polyamines were carried out on single petals, at room temperaure (20 degrees C) and in the light. The results show that putrescine, spermidine, and spermine uptake was dependent on the external pH and occurred up to high external polyamine concentrations with K(m) values of 8.6, 1.2, and 2.1 millimolar, respectively, with spermidine being the most absorbed at low concentration (17 micromolar). Putrescine and spermidine did not seem to compete for the same site of absorption. Furthermore, putrescine and spermidine uptake was not inhibited by Ca(2+), Mg(2+), and K(+) at the same concentrations (17 micromolar), whereas 1.7 millimolar Ca(2+) inhibited and K(+) enhanced spermidine uptake. The intracellular localization of the absorbed putrescine was determined using two different methods. Very little label was found in the apoplast, while most of it was localized in the 98,500g supernatant. According to our data the vacuole, which represents a substantial part of Saintpaulia parenchyma cells, could be a site of putrescine accumulation. 2,4-Dinitrophenol and diethylstilbestrol did not inhibit uptake; however, at 0 degrees C there was a 35% inhibition of spermidine uptake, compared with the controls kept at 20 degrees C as well as a 68% inhibition with 20 millimolar NaSCN.

  2. Polyamine Uptake, Kinetics, and Competition among Polyamines and between Polyamines and Inorganic Cations 1

    Science.gov (United States)

    Pistocchi, Rossella; Bagni, Nello; Creus, José A.

    1986-01-01

    Polyamine uptake, the kinetics of this uptake, and the competition among polyamines and between polyamines and inorganic cations were studied in petals of Saintpaulia ionantha Wendl. Uptake experiments using 14C-labeled polyamines were carried out on single petals, at room temperaure (20°C) and in the light. The results show that putrescine, spermidine, and spermine uptake was dependent on the external pH and occurred up to high external polyamine concentrations with Km values of 8.6, 1.2, and 2.1 millimolar, respectively, with spermidine being the most absorbed at low concentration (17 micromolar). Putrescine and spermidine did not seem to compete for the same site of absorption. Furthermore, putrescine and spermidine uptake was not inhibited by Ca2+, Mg2+, and K+ at the same concentrations (17 micromolar), whereas 1.7 millimolar Ca2+ inhibited and K+ enhanced spermidine uptake. The intracellular localization of the absorbed putrescine was determined using two different methods. Very little label was found in the apoplast, while most of it was localized in the 98,500g supernatant. According to our data the vacuole, which represents a substantial part of Saintpaulia parenchyma cells, could be a site of putrescine accumulation. 2,4-Dinitrophenol and diethylstilbestrol did not inhibit uptake; however, at 0°C there was a 35% inhibition of spermidine uptake, compared with the controls kept at 20°C as well as a 68% inhibition with 20 millimolar NaSCN. PMID:16664661

  3. [Axolemmal transporters for neurotransmitter uptake].

    Science.gov (United States)

    García-López, M

    Neurotransmission is a fundamental process in interneuronal communication. It starts with the release of the neurotransmitter following a nerve impulse and ends either by uptake by specific specific transporters or by metabolization to an inactive compound. In this review we will consider the molecular, ion dependence and electrogenic properties of the axolemal transporters for neurotransmitters and also the pathological consequences of their impairment as well as the drugs that can interact with them. Most axolemmal transporters have been cloned and grouped into two large families according to their molecular characteristics and electrogenic properties: 1. Those dependent on Na+/Cl- include transporters of GABA, noradrenaline, dopamine, serotonin, choline, proline, betaine, glycine and taurine, and 2. Those dependent on Na+/K+, which include the transporters of glutamate, alanine, serine and cysteine. The clonation of transporters has permitted (and will continue to permit) the correlation of molecular alterations of transporters with different neuro-degenerative disorders (e.g. multiple sclerosis, Parkinson's disease, Alzheimer's disease), with brain lesions (e.g. cerebral ischemia, status epilepticus) and with psychiatric alterations (e.g. schizophrenia, depression). In this respect, chemical synthesis of new selective drugs which interact with the different systems for uptake of neurotransmitters will offer new approaches to the treatment of many disorders of the central nervous system which still have no satisfactory drug treatment.

  4. Farmer Field Schools as a Springboard for Enhanced Uptake of ...

    African Journals Online (AJOL)

    agricultural technologies is through the Farmer Field Schools that have only a short history in Tanzania.This paper reviews the literature ... This discussion is then followed by a brief presentation of the history of FFS in Tanzania. The paper then makes an .... spread to other countries such as Viet Nam, Peru,. Trinidad, Nigeria ...

  5. Clinical significance of the thymidylate synthase, dihydropyrimidine dehydrogenase, and thymidine phosphorylase mRNA expressions in hepatocellular carcinoma patients receiving 5-fluorouracil-based transarterial chemoembolization treatment

    Directory of Open Access Journals (Sweden)

    Zhao H

    2013-07-01

    Full Text Available Hongyun Zhao,1,* Yuanyuan Zhao,2,* Ying Guo,1 Yan Huang,2 Suxia Lin,3 Cong Xue,2 Fei Xu,2 Yang Zhang,1 Liping Zhao,2 Zhihuang Hu,2 Li Zhang1,2 1State Key Laboratory of Oncology in South China and National Anti-Cancer Drug Clinical Research Centre, 2State Key Laboratory of Oncology in South China and Department of Medical Oncology, 3Department of Pathological Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China*These authors contributed equally to this workPurpose: To determine whether 5-fluorouracil (5-FU sensitivity is associated with the mRNA expressions of thymidylate synthase (TS, dihydropyrimidine dehydrogenase (DPD, and thymidine phosphorylase (TP in patients with hepatocellular carcinoma (HCC treated with 5-FU-based transarterial chemoembolization (TACE.Methods: Formalin-fixed, paraffin-embedded tumor specimens from 40 patients treated with 5-FU-based TACE were selected for the examination of TS, DPD, and TP expression level by a quantitative real-time reverse transcription- polymerase chain reaction (PCR technique. Patients were categorized into high and low expression groups according to the median expression level of each enzyme. Associations between the mRNA expression levels of TS, DPD, and TP and clinical parameters including treatment efficacies, clinicopathological factors, and prognosis were assessed.Results: High DPD expression was associated with worse treatment outcome, including intrahepatic disease progression rate (hazard ratio [HR] for high DPD versus low DPD, 2.212; 95% confidence interval [CI], 1.030–4.753; P = 0.042, extrahepatic disease progression rate (HR for high versus low DPD, 3.171; 95% CI, 1.003–10.023; P = 0.049, and progression-free survival (HR for high versus low DPD, 2.308; 95% CI, 1.102–4.836; P = 0.027. No correlation was found between the mRNA expression of TS/TP and treatment outcome.Conclusion: DPD mRNA expression level was negatively correlated with the clinical

  6. Connecting tropical climate change with Southern Ocean heat uptake

    Science.gov (United States)

    Hwang, Yen-Ting; Xie, Shang-Ping; Deser, Clara; Kang, Sarah M.

    2017-09-01

    Under increasing greenhouse gas forcing, climate models project tropical warming that is greater in the Northern than the Southern Hemisphere, accompanied by a reduction in the northeast trade winds and a strengthening of the southeast trades. While the ocean-atmosphere coupling indicates a positive feedback, what triggers the coupled asymmetry and favors greater warming in the northern tropics remains unclear. Far away from the tropics, the Southern Ocean (SO) has been identified as the major region of ocean heat uptake. Beyond its local effect on the magnitude of sea surface warming, we show by idealized modeling experiments in a coupled slab ocean configuration that enhanced SO heat uptake has a profound global impact. This SO-to-tropics connection is consistent with southward atmospheric energy transport across the equator. Enhanced SO heat uptake results in a zonally asymmetric La-Nina-like pattern of sea surface temperature change that not only affects tropical precipitation but also has influences on the Asian and North American monsoons.

  7. Gadopentetate dimeglumine and FDG uptake in liver metastases of colorectal carcinoma as determined with MR imaging and PET.

    NARCIS (Netherlands)

    Laarhoven, H.W.M. van; Geus-Oei, L.F. de; Wiering, B.; Lok, J.; Rijpkema, M.J.P.; Kaanders, J.H.A.M.; Krabbe, P.F.M.; Ruers, T.J.M.; Punt, C.J.A.; Kogel, A.J. van der; Oyen, W.J.G.; Heerschap, A.

    2005-01-01

    PURPOSE: To examine the in vivo relationship between fluorine 18 fluorodeoxyglucose (FDG) uptake, as measured with positron emission tomography (PET), and functional tumor vasculature, as measured with dynamic contrast material-enhanced magnetic resonance (MR) imaging, in patients with liver

  8. Gadopentetate dimeglumine and FDG uptake in liver metastases of colorectal carcinoma as determined with MR imaging and PET

    NARCIS (Netherlands)

    van Laarhoven, Hanneke W M; de Geus-Oei, Lioe-Fee; Wiering, Bastiaan; Lok, Jasper; Rijpkema, Mark; Kaanders, Johannes H A M; Krabbe, Paul F M; Ruers, Theo; Punt, Cornelis J A; van der Kogel, Albert J; Oyen, Wim J G; Heerschap, Arend

    2005-01-01

    PURPOSE: To examine the in vivo relationship between fluorine 18 fluorodeoxyglucose (FDG) uptake, as measured with positron emission tomography (PET), and functional tumor vasculature, as measured with dynamic contrast material-enhanced magnetic resonance (MR) imaging, in patients with liver

  9. Modified Feddes type stress reduction function for modeling root water uptake: Accounting for limited aeration and low water potential

    Science.gov (United States)

    Peters, Andre; Durner, Wolfgang; Iden, Sascha C.

    2017-04-01

    Modeling water flow in the soil-plant-atmosphere continuum with the Richards equation requires a model for the sink term describing water uptake by plant roots. Despite recent progress in developing process-based models of water uptake by plant roots and water flow in aboveground parts of vegetation, effective models of root water uptake are widely applied and necessary for large-scale applications. Modeling root water uptake consists of three steps, (i) specification of the spatial distribution of potential uptake, (ii) reduction of uptake due to various stress sources, and (iii) enhancement of uptake in part of the simulation domain to describe compensation. We discuss the conceptual shortcomings of the frequently used root water uptake model of Feddes and suggest a simple but effective improvement of the model. The improved model parametrizes water stress in wet soil by a reduction scheme which is formulated as function of air content where water stress due to low soil water potential is described by the original approach of Feddes. The improved model is physically more consistent than Feddes' model because water uptake in wet soil is limited by aeration which is a function of water content. The suggested modification is particularly relevant for simulations in heterogeneous soils, because stress parameters are uniquely defined for the entire simulation domain, irrespective of soil texture. Numerical simulations of water flow and root water uptake in homogeneous and stochastic heterogeneous soils illustrate the effect of the new model on root water uptake and actual transpiration. For homogeneous fine-textured soils, root water uptake never achieves its potential rate. In stochastic heterogeneous soil, water uptake is more pronounced at the interfaces between fine and coarse regions which has potential implications for plant growth, nutrient uptake and depletion.

  10. Increased muscle glucose uptake during contractions

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Richter, Erik

    1984-01-01

    We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

  11. Spring Hydrology Determines Summer Net Carbon Uptake in Northern Ecosystems

    Science.gov (United States)

    Yi, Yonghong; Kimball, John; Reichle, Rolf H.

    2014-01-01

    Increased photosynthetic activity and enhanced seasonal CO2 exchange of northern ecosystems have been observed from a variety of sources including satellite vegetation indices (such as the Normalized Difference Vegetation Index; NDVI) and atmospheric CO2 measurements. Most of these changes have been attributed to strong warming trends in the northern high latitudes (greater than or equal to 50N). Here we analyze the interannual variation of summer net carbon uptake derived from atmospheric CO2 measurements and satellite NDVI in relation to surface meteorology from regional observational records. We find that increases in spring precipitation and snow pack promote summer net carbon uptake of northern ecosystems independent of air temperature effects. However, satellite NDVI measurements still show an overall benefit of summer photosynthetic activity from regional warming and limited impact of spring precipitation. This discrepancy is attributed to a similar response of photosynthesis and respiration to warming and thus reduced sensitivity of net ecosystem carbon uptake to temperature. Further analysis of boreal tower eddy covariance CO2 flux measurements indicates that summer net carbon uptake is positively correlated with early growing-season surface soil moisture, which is also strongly affected by spring precipitation and snow pack based on analysis of satellite soil moisture retrievals. This is attributed to strong regulation of spring hydrology on soil respiration in relatively wet boreal and arctic ecosystems. These results document the important role of spring hydrology in determining summer net carbon uptake and contrast with prevailing assumptions of dominant cold temperature limitations to high-latitude ecosystems. Our results indicate potentially stronger coupling of boreal/arctic water and carbon cycles with continued regional warming trends.

  12. Mechanically triggered solute uptake in soft contact lenses.

    Science.gov (United States)

    Tavazzi, Silvia; Ferraro, Lorenzo; Fagnola, Matteo; Cozza, Federica; Farris, Stefano; Bonetti, Simone; Simonutti, Roberto; Borghesi, Alessandro

    2015-06-01

    Molecular arrangement plays a role in the diffusion of water and solutes across soft contact lenses. In particular, the uptake of solutes in hydrated contact lenses can occur as long as free water is available for diffusion. In this work, we investigated the effect of mechanical vibrations of low frequency (200 Hz) on the solute uptake. Hyaluronan, a polysaccharide of ophthalmic use, was taken as example of solute of interest. For a specific water-hydrated hydrogel material, differential scanning calorimetry experiments showed that a large fraction of the hydration water accounted for loosely-bound water, both before and after one week of daily-wear of the lenses. The size (of the order of magnitude of few hundreds of nanometers) of hyaluronan in aqueous solution was found to be less than the size of the pores of the lens observed by scanning electron microscopy. However, solute uptake in already-hydrated lenses was negligible by simple immersion, while a significant increase occurred under mechanical vibrations of 200 Hz, thus providing experimental evidence of mechanically triggered enhanced solute uptake, which is attributed to the release of interfacial loosely-bound water. Also other materials were taken into consideration. However, the effectiveness of mechanical vibrations for hyaluronan uptake is restricted to lenses containing interfacial loosely-bound water. Indeed, loosely-bound water is expected to be bound to the polymer with bonding energies of the order of magnitude of 10-100 J/g, which are compatible with the energy input supplied by the vibrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Theophylline Increases the Uptake of Radioiodine by Mouse Thyroid

    Science.gov (United States)

    Caturegli, Patrizio; Ladenson, Paul W.

    2004-01-01

    Diagnostic and therapeutic use of radioiodine in the management of thyroid disorders depends on the ability of thyroid cells to concentrate radioiodine, a process that is regulated by the intracellular increase in cAMP. We hypothesized that theophylline, a drug known to increase intracellular cAMP via inhibition of phosphodiesterase, could increase thyroidal radioiodine uptake. We tested this effect in vivo, using C57BL/6j mice, and in vitro, using Fisher rat thyroid (FRTL-5) cells. One mouse received 2.5mg theophylline i.p., whereas a control mouse received only saline. Twenty-hours after theophylline, mice were injected with 10 µCi Na125I in 0.1 mL saline through the tail vein. Mean thyroidal 125I activity was 3.3-fold higher in theophylline-treated mice than in their respective controls. Radioiodine uptake and intracellular cAMP production of FRTL-5 cells were increased by a relatively low concentration of theophylline (1 µM). Intracellular cAMP increased up to 30 min and then declined in response to 1 µM theophylline. Sera from theophylline-treated mice stimulated 125I uptake and intracellular cAMP production by FRTL-5 cells. These findings show that theophylline can enhance radioiodine uptake by thyrocytes in vivo and in vitro. The in vitro effects of theophylline on both radioiodine uptake and cAMP production in a dose-dependent manner are consistent with an action mediated by phosphodiesterase inhibition. PMID:15483348

  14. [Internal and external sources of the radiation induce the blocking of the proliferation of the human endothelial cells in culture. G2-block is induced by beta-particle 3H-thymidine and gamma-rays 137Cs].

    Science.gov (United States)

    Gil'iano, N Ia; Konevega, L V; Stepanov, S I; Semenova, E G; Noskin, L A

    2007-01-01

    We found that low doses (0.12-0.46Gy) of (methyl-) 3H-thymidine incorporated into human endothelial cells induce the accumulation cells in G2-phase of the cell cycle. Temperate doses of (1-6 Gy) gamma-rays 137Cs were less effective in the G2-block estimated by flow cytometry analysis of DNA content. Furthermore, the induced the high level of the chromosome aberrations (bridges and fragments in anaphases). 1Gy of gamma-ray 137Cs and 0.005 Gy of beta-rays induced the same per cent of the aberrant anaphases. Apparently, that the damages of the cellular hereditary structures are responsible for the blocking of the cellular proliferation in G2-phase. We suggest, that the disposition 3H-thymidine into radiosensitive target (DNA) defines the high cytotoxic of the beta-rays.

  15. Facilitation of phosphorus uptake in maize plants by mycorrhizosphere bacteria

    DEFF Research Database (Denmark)

    Battini, Fabio; Grønlund, Mette; Agnolucci, Monica

    2017-01-01

    A major challenge for agriculture is to provide sufficient plant nutrients such as phosphorus (P) to meet the global food demand. The sufficiency of P is a concern because of it's essential role in plant growth, the finite availability of P-rock for fertilizer production and the poor plant...... availability of soil P. This study investigated whether biofertilizers and bioenhancers, such as arbuscular mycorrhizal fungi (AMF) and their associated bacteria could enhance growth and P uptake in maize. Plants were grown with or without mycorrhizas in compartmented pots with radioactive P tracers and were...... inoculated with each of 10 selected bacteria isolated from AMF spores. Root colonization by AMF produced large plant growth responses, while seven bacterial strains further facilitated root growth and P uptake by promoting the development of AMF extraradical mycelium. Among the tested strains, Streptomyces...

  16. Mining iron: iron uptake and transport in plants.

    Science.gov (United States)

    Kim, Sun A; Guerinot, Mary Lou

    2007-05-25

    Iron uptake in plants is highly regulated in order to supply amounts sufficient for optimal growth while preventing excess accumulation. In response to iron deficiency, plants induce either reduction-based or chelation-based mechanisms to enhance iron uptake from the soil. Genes involved in each mechanism have been identified from various model plants including Arabidopsis and rice. Iron transport within plants is also tightly controlled. New information has emerged on transporters that play a role in xylem loading and phloem loading/unloading of iron, and on the iron chelators involved in iron homeostasis. Some of the components regulating iron deficiency responses also have been elucidated, demonstrating that iron dependent gene regulation occurs at both the transcriptional and post-transcriptional levels.

  17. Radioiodine uptake in inactive pulmonary tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Bakheet, S.M.; Powe, J.; Al Suhaibani, H. [Department of Radiology, King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia); Hammami, M.M.; Bazarbashi, M. [Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia)

    1999-06-01

    Radioiodine may accumulate at sites of inflammation or infection. We have seen such accumulation in six thyroid cancer patients with a history of previously treated pulmonary tuberculosis. We also review the causes of false-positive radioiodine uptake in lung infection/inflammation. Eight foci of radioiodine uptake were seen on six iodine-123 diagnostic scans. In three foci, the uptake was focal and indistinguishable from thyroid cancer pulmonary metastases from thyroid cancer. In the remaining foci, the uptake appeared nonsegmental, linear or lobar, suggesting a false-positive finding. The uptake was unchanged, variable in appearance or non-persistent on follow-up scans and less extensive than the fibrocystic changes seen on chest radiographs. In the two patients studied, thyroid hormone level did not affect the radioiodine lung uptake and there was congruent gallium-67 uptake. None of the patients had any evidence of thyroid cancer recurrence or of reactivation of tuberculosis and only two patients had chronic intermittent chest symptoms. Severe bronchiectasis, active tuberculosis, acute bronchitis, respiratory bronchiolitis, rheumatoid arthritis-associated lung disease and fungal infection such as Allescheria boydii and aspergillosis can lead to different patterns of radioiodine chest uptake mimicking pulmonary metastases. Pulmonary scarring secondary to tuberculosis may predispose to localized radioiodine accumu