The attachment of V79 and human periodontal ligament fibroblasts on periodontally involved root surfaces following treatment with EDTA, citric acid, or tetracycline HCL: an SEM in vitro study.

PubMed

Chandra, R Viswa; Jagetia, Ganesh Chandra; Bhat, K Mahalinga

2006-02-15

The present in vitro study has been designed to establish and compare the effects of citric acid, EDTA, and tetracycline HCl on human periodontally diseased roots on the structure, attachment, and orientation of V79 (primary Chinese hamster lung fibroblasts) cells and human periodontal ligament fibroblasts (HPDL). Commercially available V79 cells and HPDL derived from healthy human third molars were used in this study. These fibroblasts were left in solution for seven days in order to attain confluence. Forty single-rooted teeth were obtained from patients diagnosed with periodontitis. The crown part was removed under constant irrigation and the root was split vertically into two equal halves, thus, yielding 80 specimens. Following scaling and root planing, the specimens were washed with phosphate buffered saline (PBS) and kept in 50 microg/ml gentamycin sulphate solution for 24 hours. The root pieces were then treated as follows: citric acid at pH 1, 24% EDTA, or with a 10% solution of tetracycline HCl and were then placed in V79 fibroblast cultures and HPDL cultures. The specimens were harvested after four weeks and were fixed in 2.5% glutaraldehyde in PBS before preparation for scanning electron microscopy (SEM). The behavior of V79 cells was similar to that of human periodontal ligament cells on root conditioned surfaces. V79 and HPDL showed a healthy morphology on root surfaces treated with citric acid and EDTA and a relatively unhealthy appearance on root surfaces treated with tetracycline HCl and distilled water (control group). The results suggest the use of citric acid and EDTA as root conditioning agents favorably affects the migration, attachment, and morphology of fibroblasts on human root surfaces, which may play a significant role in periodontal healing and regeneration.

Heterologous expression of equine CYP3A94 and investigation of a tunable system to regulate co-expressed NADPH P450 oxidoreductase levels.

PubMed

Dettwiler, Ramona; Schmitz, Andrea L; Plattet, Philippe; Zielinski, Jana; Mevissen, Meike

2014-01-01

The activity of cytochrome P450 enzymes depends on the enzyme NADPH P450 oxidoreductase (POR). The aim of this study was to investigate the activity of the equine CYP3A94 using a system that allows to regulate the POR protein levels in mammalian cells. CYP3A94 and the equine POR were heterologously expressed in V79 cells. In the system used, the POR protein regulation is based on a destabilizing domain (DD) that transfers its instability to a fused protein. The resulting fusion protein is therefore degraded by the ubiquitin-proteasome system (UPS). Addition of "Shield-1" prevents the DD fusion protein from degradation. The change of POR levels at different Shield-1 concentrations was demonstrated by cytochrome c reduction, Western immunoblot analysis, and immunocytochemistry. The alteration of CYP3A94 activity was investigated using a substrate (BFC) known to detect CYP3A4 activity. Equine CYP3A94 was demonstrated to be metabolically active and its activity could be significantly elevated by co-expression of POR. Cytochrome c reduction was significantly increased in V79-CYP3A94/DD-POR cells compared to V79-CYP3A94 cells. Surprisingly, incubation with different Shield-1 concentrations resulted in a decrease in POR protein shown by Western immunoblot analysis. Cytochrome c reduction did not change significantly, but the CYP3A94 activity decreased more than 4-fold after incubation with 500 nM and 1 µM Shield-1 for 24 hours. No differences were obtained when V79-CYP3A94 POR cells with and without Shield-1 were compared. The basal activity levels of V79-CYP3A94/DD-POR cells were unexpectedly high, indicating that DD/POR is not degraded without Shield-1. Shield-1 decreased POR protein levels and CYP3A94 activity suggesting that Shield-1 might impair POR activity by an unknown mechanism. Although regulation of POR with the pPTuner system could not be obtained, the cell line V79-CYP3A94/DD-POR system can be used for further experiments to characterize the equine CYP3A94 since the CYP activity was significantly enhanced with co-expressed POR.

Heterologous Expression of Equine CYP3A94 and Investigation of a Tunable System to Regulate Co-Expressed NADPH P450 Oxidoreductase Levels

PubMed Central

Dettwiler, Ramona; Schmitz, Andrea L.; Plattet, Philippe; Zielinski, Jana; Mevissen, Meike

2014-01-01

The activity of cytochrome P450 enzymes depends on the enzyme NADPH P450 oxidoreductase (POR). The aim of this study was to investigate the activity of the equine CYP3A94 using a system that allows to regulate the POR protein levels in mammalian cells. CYP3A94 and the equine POR were heterologously expressed in V79 cells. In the system used, the POR protein regulation is based on a destabilizing domain (DD) that transfers its instability to a fused protein. The resulting fusion protein is therefore degraded by the ubiquitin-proteasome system (UPS). Addition of “Shield-1” prevents the DD fusion protein from degradation. The change of POR levels at different Shield-1 concentrations was demonstrated by cytochrome c reduction, Western immunoblot analysis, and immunocytochemistry. The alteration of CYP3A94 activity was investigated using a substrate (BFC) known to detect CYP3A4 activity. Equine CYP3A94 was demonstrated to be metabolically active and its activity could be significantly elevated by co-expression of POR. Cytochrome c reduction was significantly increased in V79-CYP3A94/DD-POR cells compared to V79-CYP3A94 cells. Surprisingly, incubation with different Shield-1 concentrations resulted in a decrease in POR protein shown by Western immunoblot analysis. Cytochrome c reduction did not change significantly, but the CYP3A94 activity decreased more than 4-fold after incubation with 500 nM and 1 µM Shield-1 for 24 hours. No differences were obtained when V79-CYP3A94 POR cells with and without Shield-1 were compared. The basal activity levels of V79-CYP3A94/DD-POR cells were unexpectedly high, indicating that DD/POR is not degraded without Shield-1. Shield-1 decreased POR protein levels and CYP3A94 activity suggesting that Shield-1 might impair POR activity by an unknown mechanism. Although regulation of POR with the pPTuner system could not be obtained, the cell line V79-CYP3A94/DD-POR system can be used for further experiments to characterize the equine CYP3A94 since the CYP activity was significantly enhanced with co-expressed POR. PMID:25415624

The Major DNA Repair Pathway after Both Proton and Carbon-Ion Radiation is NHEJ, but the HR Pathway is More Relevant in Carbon Ions

PubMed Central

Gerelchuluun, Ariungerel; Manabe, Eri; Ishikawa, Takaaki; Sun, Lue; Itoh, Kazuya; Sakae, Takeji; Suzuki, Kenshi; Hirayama, Ryoichi; Asaithamby, Aroumougame; Chen, David J.; Tsuboi, Koji

2017-01-01

The purpose of this study was to identify the roles of non-homologous end-joining (NHEJ) or homologous recombination (HR) pathways in repairing DNA double-strand breaks (DSBs) induced by exposure to high-energy protons and carbon ions (C ions) versus gamma rays in Chinese hamster cells. Two Chinese hamster cell lines, ovary AA8 and lung fibroblast V79, as well as various mutant sublines lacking DNA-PKcs (V3), X-ray repair cross-complementing protein-4 [XRCC4 (XR1), XRCC3 (irs1SF) and XRCC2 (irs1)] were exposed to gamma rays (137Cs), protons (200 MeV; 2.2 keV/μm) and C ions (290 MeV; 50 keV/μm). V3 and XR1 cells lack the NHEJ pathway, whereas irs1 and irs1SF cells lack the HR pathway. After each exposure, survival was measured using a clonogenic survival assay, in situ DSB induction was evaluated by immunocytochemical analysis of histone H2AX phosphorylation at serine 139 (γ-H2AX foci) and chromosome aberrations were examined using solid staining. The findings from this study showed that clonogenic survival clearly depended on the NHEJ and HR pathway statuses, and that the DNA-PKcs−/− cells (V3) were the most sensitive to all radiation types. While protons and γ rays yielded almost the same biological effects, C-ion exposure greatly enhanced the sensitivity of wild-type and HR-deficient cells. However, no significant enhancement of sensitivity in cell killing was seen after C-ion irradiation of NHEJ deficient cells. Decreases in the number of γ-H2AX foci after irradiation occurred more slowly in the NHEJ deficient cells. In particular, V3 cells had the highest number of residual γ-H2AX foci at 24 h after C-ion irradiation. Chromosomal aberrations were significantly higher in both the NHEJ- and HR-deficient cell lines than in wild-type cell lines in response to all radiation types. Protons and gamma rays induced the same aberration levels in each cell line, whereas C ions introduced higher but not significantly different aberration levels. Our results suggest that the NHEJ pathway plays an important role in repairing DSBs induced by both clinical proton and C-ion beams. Furthermore, in C ions the HR pathway appears to be involved in the repair of DSBs to a greater extent compared to gamma rays and protons. PMID:25738894

Cytotoxicity and genotoxicity induced by coal and coal fly ash particles samples in V79 cells.

PubMed

León-Mejía, Grethel; Silva, Luis F O; Civeira, Matheus S; Oliveira, Marcos L S; Machado, Miriana; Villela, Izabel Vianna; Hartmann, Andreas; Premoli, Suziane; Corrêa, Dione Silva; Da Silva, Juliana; Henriques, João Antônio Pêgas

2016-12-01

Exposure to coal and coal ashes can cause harmful effects in in vitro and in vivo systems, mainly by the induction of oxidative damage. The aim of this work was to assess cytotoxic and genotoxic effects using the V79 cell line treated with coal and coal fly ash particles derived from a coal power plant located in Santa Catarina, Brazil. Two coal samples (COAL11 and COAL16) and two coal fly ash samples (CFA11 and CFA16) were included in this study. COAL16 was co-firing with a mixture of fuel oil and diesel oil. The comet assay data showed that exposure of V79 cells to coal and coal fly ash particles induced primary DNA lesions. Application of lesion-specific endonucleases (FPG and ENDO III) demonstrated increased DNA effects indicating the presence of high amounts of oxidative DNA lesions. The cytokinesis-block micronucleus cytome assay analysis showed that exposure of V79 cells to high concentrations of coal and coal fly ash particles induced cytotoxic effects (apoptosis and necrosis) and chromosomal instability (nucleoplasmic bridges, nuclear buds, and micronucleus (MN) formation). These results may be associated with compounds contained in the surface of the particles as hazardous elements, ultrafine/nanoparticles, and polycyclic aromatic hydrocarbons (PAHs) which were detected in the samples. Graphical abstract ᅟ.

In vitro and in silico modeling of chromosomal instability

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri; Krasavin, Eugene; Govorun, Raisa; Koshlan, Igor; Pyatenko, Valentina; Korovchuk, Olga; Khvostunov, Igor; Sevankaev, Alexander

Exposure to ionizing radiation increases cancer risk in human population. Cancer is thought to originate from an altered expression of certain number of specific genes. It is widely recognized that chromosome aberrations (CA) are involved in stable change in expression of genes by gain or loss of their functions. Thus CA can contribute to initiation or progression of cancer. Radiation induces CA immediately after exposure (in first cell cycle) and results in formation of delayed CA in descendants of irradiated cells, or chromosomal instability phenotype (CI). Therefore quantification of CI is a prerequisite of any mechanistic model of radiation induced cancer risks. To quantify CI we designed a set of in vitr o and in silico experiments. Two experimental models for study of CI in vitro, CHO-K1 wild-type and V79 HPRT-mutant cells, were exploited. Chromosome and chromatid type aberrations (Giemsa staining) were scored following exposure to gamma-radiation and accelerated ions (protons, LET=0.22 keV/µm, 7 Li3+ , LET=20 keV/µm, 14 7+ N , LET=77 keV/µm). The obtained results suggested that slowly growing colonies of HPRT mutant cells originating from lowand high-LET irradiated wt V79 cells were formed. After 14 N7+ ions irradiation about 50-100% of colonies had the decreased growth rate and CI phenotype was observed mainly in slowly growing colonies. High, compared to control, level of unstable CA (dicentrics) was observed in the progeny of gamma-irradiated CHO-K1 cells at different time points up to 30 cell generations. CA frequency, the number of cells with aberrations and the shape of a CA-vs-time curve were found to be dependent on the cell culture state (stationary or logarithmic phase) in which they were irradiated. Inhibition of replication and repair DNA synthesis by ara-C and hydroxyurea resulted in small modification of CA dynamics for stat-phase cells. For log-phase cell culture, in contrast, DNA synthesis inhibitors drastically impacted CA dynamics. In order to investigate the relationship between radiation-induced DNA double-strand breaks, CA and their transmission through cell division cycles we proposed a mechanism of CI incorporating the idea of breakage-fusion-bridge cycle. It explains in biophysical terms the generation of CA, in particular, of unstable type, in cells survived radiation exposure. The in silico experiments were carried out to elucidate different scenarios of CI. The computational data showed that the increased frequency of delayed dicentrics at different times after exposure could be well described for both stat and log-phase exposed cultures by the proposed mechanism if the fraction of cells in different cell cycle phases at the time of iradiation is taken into account. The perspectives for further experimental and theoretical mechanistic study of CI and possible implications for cancer risk modeling are discussed.

Potentiometric Biosensor for Studying Hydroquinone Cytotoxicity in vitro

PubMed Central

Wang, Yanyan; Chen, Qiang; Zeng, Xiangqun

2009-01-01

Many processes in living cells have electrochemical characteristics that are suitable for measurement by potentiometric biosensors. Potentiometric biosensors allow non invasive, real-time monitoring of the extracellular environment changes by measuring the potential at cell/sensor interface. This can be used as an indicator for overall cell cytotoxicity. The present work employs a potentiometric sensor array to investigate the cytotoxicity of hydroquinone to cultured mammalian V79 cells. Various electrode substrates (Au, PPy-HQ and PPy-PS) used for cell growth were designed and characterized. The controllable release of hydroquinone from PPy substrates was studied. Our results showed that hydroquinone exposure affected cell proliferation and delayed cell growth and attachment in a dose-dependent manner. Additionally, we have shown that exposure of V79 cells to hydroquinone at low doses (i.e 5μM) for more than 15 hours allows V79 cells to gain enhanced adaptability to survive exposure to high toxic HQ doses afterwards. Compared with traditional methods, the potentiometric biosensor not only provides non-invasive and real time monitoring of the cellular reactions but also is more sensitive for in vitro cytotoxicity study. By real time and non-invasive monitoring of the extracellular potential in vitro, the potentiometric sensor system represents a promising biosensor system for drug discovery. PMID:19926470

A tryptophan-rich motif in the human parainfluenza virus type 2 V protein is critical for the blockade of toll-like receptor 7 (TLR7)- and TLR9-dependent signaling.

PubMed

Kitagawa, Yoshinori; Yamaguchi, Mayu; Zhou, Min; Komatsu, Takayuki; Nishio, Machiko; Sugiyama, Tsuyoshi; Takeuchi, Kenji; Itoh, Masae; Gotoh, Bin

2011-05-01

Plasmacytoid dendritic cells (pDCs) do not produce alpha interferon (IFN-α) unless viruses cause a systemic infection or overcome the first-line defense provided by conventional DCs and macrophages. We show here that even paramyxoviruses, whose infections are restricted to the respiratory tract, have a V protein able to prevent Toll-like receptor 7 (TLR7)- and TLR9-dependent IFN-α induction specific to pDCs. Mutational analysis of human parainfluenza virus type 2 demonstrates that the second Trp residue of the Trp-rich motif (Trp-X(3)-Trp-X(9)-Trp) in the C-terminal domain unique to V, a determinant for IRF7 binding, is critical for the blockade of TLR7/9-dependent signaling.

Involvement of basic fibroblast growth factor in suramin-induced inhibition of V79/AP4 fibroblast cell proliferation.

PubMed Central

Bernardini, N.; Giannessi, F.; Bianchi, F.; Dolfi, A.; Lupetti, M.; Citti, L.; Danesi, R.; Del Tacca, M.

1993-01-01

The V79/AP4 Chinese hamster fibroblasts were densely stained with the anti-basic fibroblast growth factor (bFGF) antibody demonstrating an endogenous production of the peptide. The in vitro proliferation of these cells was stimulated by exogenous bFGF and the maximum growth (259% increase in 3H-thymidine incorporation into DNA) was reached with bFGF 10 ng ml-1. Inhibition of bFGF-mediated mitogenic pathway was obtained with a 15-mer antisense oligodeoxynucleotide targeted against bFGF mRNA and with suramin, a drug which blocks the biological activity of heparin-binding growth factors. bFGF antisense oligomer reduced the synthesis of DNA by 79.5 and 89.5% at 20 and 60 microM, respectively; this effect was reversed by the addition of exogenous bFGF to the culture medium. A short-term exposure to suramin 300 micrograms ml-1 produced a modest reduction in 3H-thymidine incorporation but suppressed the mitogenic effect of bFGF on V79/AP4 cells. In cells treated with suramin 300 micrograms ml-1 the drug concentration increased linearly over 3 days, reaching 13.15 micrograms mg-1 of protein; cell proliferation was inhibited in a dose-related manner as evaluated by the colony formation assay (IC50: 344.22 micrograms ml-1) and by the number of mitoses observed in culture. Furthermore, the drug induced ultrastructural alterations, consisting of perinuclear cisternae swelling, chromatin condensation, nucleolar segregation and cytoplasmic vacuolations. These findings demonstrated that the endogenous production of bFGF plays an important role in V79/AP4 fibroblasts proliferation, and the inhibition of bFGF-mediated mitogenic signalling with bFGF antisense oligomer or suramin is an effective mean of reducing cell growth. Images Figure 1 Figure 5 Figure 6 PMID:7685616

[Short-term screening of anticarcinogenic ingredients of tea by cell biology assays].

PubMed

Liu, L; Han, C; Chen, J

1998-01-01

By using a panel of short term cell biology assays, several ingredients of tea (tea pigments, caffeine, tea polysaccharide, tea polyphenols tablet and mixed tea) were screened in order to investigate their anticarcinogenic effects. The cytokinesis block micronuclei test in V79 cells induced by mitomycin, the test of metabolic cooperation between V79 and M cells and the test of growth ability of Hela cells in soft agar were used in the screening. The results showed that the six kinds of tea ingredients tested were effective in the test involved in different stages of carcinogenesis, i.e. initiation, promotion and progression. The effects of mixed tea and tea pigments were the strongest among the ingredients tested.

Classification and Segmentation of Nanoparticle Diffusion Trajectories in Cellular Micro Environments

PubMed Central

Kroll, Alexandra; Haramagatti, Chandrashekara R.; Lipinski, Hans-Gerd; Wiemann, Martin

2017-01-01

Darkfield and confocal laser scanning microscopy both allow for a simultaneous observation of live cells and single nanoparticles. Accordingly, a characterization of nanoparticle uptake and intracellular mobility appears possible within living cells. Single particle tracking allows to measure the size of a diffusing particle close to a cell. However, within the more complex system of a cell’s cytoplasm normal, confined or anomalous diffusion together with directed motion may occur. In this work we present a method to automatically classify and segment single trajectories into their respective motion types. Single trajectories were found to contain more than one motion type. We have trained a random forest with 9 different features. The average error over all motion types for synthetic trajectories was 7.2%. The software was successfully applied to trajectories of positive controls for normal- and constrained diffusion. Trajectories captured by nanoparticle tracking analysis served as positive control for normal diffusion. Nanoparticles inserted into a diblock copolymer membrane was used to generate constrained diffusion. Finally we segmented trajectories of diffusing (nano-)particles in V79 cells captured with both darkfield- and confocal laser scanning microscopy. The software called “TraJClassifier” is freely available as ImageJ/Fiji plugin via https://git.io/v6uz2. PMID:28107406

In vitro studies on the genotoxicity of 2,4-dichloro-6-nitrophenol ammonium (DCNPA) and its major metabolite.

PubMed

Heng, Z C; Ong, T; Nath, J

1996-06-12

2,4-dichloro-6-nitrophenol ammonium (DCNPA) is used as a herbicide. However, information on the potential health hazards of DCNPA is limited. In a previous study, we found that DCNPA is genotoxic to Bacillus subtilis and yeast. Further studies were performed to determine whether DCNPA and its major metabolite, 2,4-dichloro-6-aminophenol (DCAP), can induce reverse mutations in Salmonella, gene mutations at the HPRT locus, sister chromatid exchanges (SCEs) and micronuclei (MN) in V79 cells. Results show that DCNPA does not produce a positive response for any endpoint at concentrations tested. However, treatment of V79 cultures with DCAP caused a significant increase in SCEs and MN in a concentration-dependent manner. These results indicate that DCAP damages DNA and causes chromosomal aberrations in V79 cells. Therefore, DCNPA could pose potential health hazards to populations exposed to this herbicide.

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reichel, Christian, E-mail: christian.reichel@ise.fraunhofer.de; National Renewable Energy Laboratory; Feldmann, Frank

Passivated contacts (poly-Si/SiO{sub x}/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF{sub 2}), the ion implantation dose (5 × 10{sup 14 }cm{sup −2} to 1 × 10{sup 16 }cm{sup −2}), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells.more » Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV{sub oc}) of 725 and 720 mV, respectively. For p-type passivated contacts, BF{sub 2} implantations into intrinsic a-Si yield well passivated contacts and allow for iV{sub oc} of 690 mV, whereas implanted B gives poor passivation with iV{sub oc} of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V{sub oc} of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF{sub 2} implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V{sub oc} of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.« less

Hypoxic cell sensitizers and heavy charged-particle radiations.

PubMed Central

Chapman, J. D.; Urtasun, R. C.; Blakely, E. A.; Smith, K. C.; Tobias, C. A.

1978-01-01

Stationary-phase populations of Chinese hamster V-79 cells were irradiated with 250 kV X-rays and the Bragg peaks (spread to a width of 4 cm) of energetic He-, C-, Ne-, and A-ion beams produced at the 184-inch cyclotron and BEVALAC at Lawrence Berkeley Laboratory. Survival curves were generated with each radiation for cells suspended in air-saturated and nitrogen-saturated medium with and without sensitizer present. The oxygen enhancement ratios (OERs) measured for X-rays with 1mM metronidazole and 0.5 mM misonidazole were 2.0 and 1.6 respectively. The OERs without sensitizer for He-, C-, Ne-, and A-ion Bragg peaks were 2.4, 1.7, 1.6 and 1.4 respectively. For each type of radiation tested the presence of hypoxic-cell sensitizers resulted in an additional reduction in the measured OERs, indicating that these drugs should be of benefit in the radiotherapy planned with these and other high LET radiations. PMID:277223

Optimized shielding for space radiation protection

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Cucinotta, F. A.; Kim, M. H.; Schimmerling, W.

2001-01-01

Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and energies. For example, C3H10T1/2 cells, V79 cells, and Harderian gland tumors have been described by various track-structure dependent response models. The attenuation of GCR induced biological effects depends strongly on the biological endpoint, response model used, and material composition. Optimization of space shielding is then driven by the nature of the response model and the transmission characteristics of the given material.

Optimized Shielding for Space Radiation Protection

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Cucinotta, F. A.; Kim, M.-H. Y.; Schimmerling, W.

2000-01-01

Abstract. Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and energies. For example, C3H10T1/2 cells, V79 cells, and Harderian gland tumors have been described by various track-structure dependent response models. The attenuation of GCR induced biological effects depends strongly on the biological endpoint, response model used, and material composition. Optimization of space shielding is then driven by the nature of the response model and the transmission characteristics of the given material.

The indole compound NC009-1 inhibits aggregation and promotes neurite outgrowth through enhancement of HSPB1 in SCA17 cells and ameliorates the behavioral deficits in SCA17 mice.

PubMed

Chen, Chiung-Mei; Chen, Wan-Ling; Hung, Chen-Ting; Lin, Te-Hsien; Chao, Chih-Ying; Lin, Chih-Hsin; Wu, Yih-Ru; Chang, Kuo-Hsuan; Yao, Ching-Fa; Lee-Chen, Guey-Jen; Su, Ming-Tsan; Hsieh-Li, Hsiu Mei

2018-06-21

Spinocerebellar ataxia type 17 (SCA17) is caused by the expansion of translated CAG repeat in the TATA box binding protein (TBP) gene encoding a long polyglutamine (polyQ) tract in the TBP protein, which leads to intracellular accumulation of aggregated TBP and cell death. The molecular chaperones act in preventing protein aggregation to ameliorate downstream harmful events. In this study, we used Tet-On cells with inducible SCA17 TBP/Q 79 -GFP expression to test five in-house NC009 indole compounds for neuroprotection. We found that both aggregation and polyQ-induced reactive oxygen species can be significantly prohibited by the tested NC009 compounds in Tet-On TBP/Q 79 293 cells. Among the five indole compounds, NC009-1 up-regulated expression of heat shock protein family B (small) member 1 (HSPB1) chaperone to reduce polyQ aggregation and promote neurite outgrowth in neuronal differentiated TBP/Q 79 SH-SY5Y cells. The increased HSPB1 thus ameliorated the increased BH3 interacting domain death agonist (BID), cytochrome c (CYCS) release, and caspase 3 (CASP3) activation which result in apoptosis. Knock down of HSPB1 attenuated the effects of NC009-1 on TBP/Q 79 SH-SY5Y cells, suggesting that HSPB1 might be one of the major pathways involved for NC009-1 effects. NC009-1 further reduced polyQ aggregation in Purkinje cells and ameliorated behavioral deficits in SCA17 TBP/Q 109 transgenic mice. Our results suggest that NC009-1 has a neuroprotective effect on SCA17 cell and mouse models to support its therapeutic potential in SCA17 treatment. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative ecotoxicity of potential biofuels to water flea (Daphnia magna), zebrafish (Danio rerio) and Chinese hamster (Cricetulus griseus) V79 cells.

PubMed

Heger, Sebastian; Du, Miaomiao; Bauer, Kevin; Schäffer, Andreas; Hollert, Henner

2018-08-01

The ecotoxicity of two biofuel candidates (1‑octanol and 2‑butanone) was investigated by an integrative test strategy using three bioassays: the acute immobilisation test with water flea (D. magna), the fish embryo acute toxicity test with zebrafish (Danio rerio) and the in vitro micronucleus assay with Chinese hamster (Cricetulus griseus) V79 cells. The median effective concentration (EC 50 ) values were 14.9±0.66mgL -1 for 1‑octanol, and 2152.1±44.6mgL -1 for 2‑butanone in the D. magna test. Both 1‑octanol and 2‑butanone caused teratogenic and lethal effects on zebrafish embryos, while exposure to 1‑octanol significantly induced these effects at concentrations ≥2.0mgL -1 . These results indicate that 1‑octanol exert much higher ecotoxicity than 2‑butanone to D. magna and zebrafish embryos. Moreover, both 1‑octanol and 2‑butanone did not cause significant genotoxic effects, while their metabolites significantly induced micronuclei in V79 cells. The present study proposed an integrative test approach to evaluate the potential ecotoxicity of biofuels using simple, quick and inexpensive bioassays. Copyright © 2018 Elsevier B.V. All rights reserved.

In vitro micronuclei tests to evaluate the genotoxicity of surface water under the influence of tanneries.

PubMed

Lemos, A O; Oliveira, N C D; Lemos, C T

2011-06-01

Leather manufacturing has a high potential for environmental pollution due to hides and chemicals that are not completely absorbed during the tanning process. This study aims to investigate the mutagenic potential of surface water samples from Cadeia and Feitoria rivers (RS, Brazil) in areas influenced by tanneries and leather footwear industry. Micronucleus assays using V79 cells and human lymphocytes were used. Cells were exposed to surface water collected bimonthly from three sites for a year, totaling six samples. Significant MN induction in human lymphocytes was shown by 83% of samples from sites FEI001 and CAD001 located downstream from the industrial area, followed by FEI004 (33%), upstream. Only a single sample from site FEI004 showed a positive response for MN in V79 cells. Thirteen discordant and five concordant responses were found between the two in vitro tests. Mutagenic agents were found at the sites where chemical quality was worst, corroborating studies on chronic toxicity, oxidative stress and mutagenicity performed in this area. The assay using human lymphocytes was more sensitive than V79 cells to detect the contaminants from this area, showing that it is an excellent biomarker of environmental genotoxicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

The role of human cytochrome P4503A4 in biotransformation of tissue-specific derivatives of 7H-dibenzo[c,g]carbazole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mesarosova, Monika; Valovicova, Zuzana; Srancikova, Annamaria

2011-09-15

The environmental pollutant 7H-dibenzo[c,g]carbazole (DBC) and its derivative, 5,9-dimethylDBC (DiMeDBC), produced significant and dose-dependent levels of micronuclei followed by a substantial increase in the frequency of apoptotic cells in the V79MZh3A4 cell line stably expressing the human cytochrome P450 (hCYP) 3A4. In contrast, neither micronuclei nor apoptosis were found in cells exposed to the sarcomagenic carcinogen, N-methylDBC (N-MeDBC). A slight but significant level of gene mutations and DNA adducts detected in V79MZh3A4 cells treated with N-MeDBC, only at the highest concentration (30 {mu}M), revealed that this sarcomagenic carcinogen was also metabolized by hCYP3A4. Surprisingly, DBC increased the frequency of 6-thioguaninemore » resistant (6-TG{sup r}) mutations only at the highest concentration (30 {mu}M), while DiMeDBC failed to increase the frequency of these mutations. The resistance to 6-thioguanine is caused by the mutations in the hypoxanthine-guanine phosphoribosyltransferase (Hprt) gene. The molecular analysis of the coding region of Hprt gene showed a deletion of the entire exon 8 in DiMeDBC-induced 6-TG{sup r} mutants, while no changes in the nucleotide sequences were identified in 6-TG{sup r} mutants produced by DBC and N-MeDBC. Based on our results, we suggest that hCYP3A4 is involved in the metabolism of DBC and its tissue-specific derivatives. While hCYP3A4 probably plays an important role in biotransformation of the liver carcinogens, DBC and DiMeDBC, it might only have a marginal function in N-MeDBC metabolism. - Highlights: > DBC activation via CYP3A4 resulted in micronuclei, DNA adduct formation and mutations in V79MZh3A4 cells. > The CYP3A4-mediated DiMeDBC activation caused micronuclei followed by apoptosis in V79MZh3A4 cells. > The genotoxic effects produced by N-MeDBC in V79MZh3A4 cells were negligible. > The hCYP3A4 may play an important role in DBC and DiMeDBC metabolism. > The CYP3A4 might only have a marginal function in N-MeDBC metabolism.« less

Induction of mutagenesis and alterations in gene expression by tumorigenic chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huberman, E.

1979-01-01

To determine the relationship between mutagenesis and carcinogenesis, a series of eleven polycyclic hydrocarbons with different degrees of carcinogenicity were tested in the cell-mediated mutagenesis assay for the induction of ouabain-resistant mutants. Four carcinogenic hydrocarbons induced ouabain-resistant mutants; five noncarcinogenic hydrocarbons were not mutagenic. Results indicated that there was a relationship between mutagenesis and the degree of carcinogenicity of polycyclic hydrocarbons after enhancement of their metabolism by aminophylline. To study liver carcinogens a system was developed for cocultivating primary liver cells and V79 hamster cells. In this system the nitrosamines and aflatoxins were metabolized by liver cells to intermediates thatmore » were mutagenic to the V79 cells. In experiments using human cells, tumor-promoting phorbol esters induced terminal differentiation while in other studies, in which avian and murine cells were employed, they inhibited differentiation. The results imply that human cells may respond differently from mouse and chicken cells to the biological effects of phorbol diesters. (HLW)« less

Ultraviolet-induced sister chromatid exchanges in V-79 cells with normal and BrdUrd-substituted DNA and the influence of intercalating substances and cysteine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Speit, G.; Mehnert, K.; Wolf, M.

1982-06-01

The influence of intercalating substances (proflavine, ethidium bromide) and of an SH compound (L-cysteine) on uv-induced sister chromatid exchanges (SCEs) was investigated in V-79 cells with normal and BrdUrd-substituted DNA. The results are discussed in relation to the primary damages leading to SCE induction produced by uv irradiation. The data indicate that neither the pyrimidine dimers nor DNA single-strand breaks are the primary cause of SCE induction, and that the damages leading to SCEs by uv irradiation differ from those which cause chromosome aberrations.

The antioxidant and antigenotoxic properties of citrus phenolics limonene and naringin.

PubMed

Bacanlı, Merve; Başaran, A Ahmet; Başaran, Nurşen

2015-07-01

Phenolic compounds not only contribute to the sensory qualities of fruits and vegetables but also exhibit several health protective properties. Limonene and naringin are the most popular phenolics found in Citrus plants. In this study, we investigated the antioxidant capacities of limonene and naringin by the trolox equivalent antioxidant capacity (TEAC) assay and the cytotoxic effects by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in Chinese hamster fibroblast (V79) cells. The genotoxic potentials of limonene and naringin were evaluated by micronucleus (MN) and alkaline COMET assays in human lymphocytes and V79 cells. Limonene and naringin, were found to have antioxidant activities at concentrations of 2-2000 µM and 5-2000 µM respectively. IC50 values of limonene and naringin were found to be 1265 µM and 9026 µM, respectively. Limonene at the concentrations below 10,000 µM and naringin at the all concentrations studied, have not exerted genotoxic effects in lymphocytes and in V79 cells. Limonene and naringin at all concentrations revealed a reduction in the frequency of MN and DNA damage induced by H2O2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bombyx mori nucleopolyhedrovirus ORF79 is a per os infectivity factor associated with the PIF complex.

PubMed

Dong, Zhan-Qi; Zhang, Jun; Chen, Xue-Mei; He, Qian; Cao, Ming-Ya; Wang, La; Li, Hai-Qing; Xiao, Wen-Fu; Pan, Cai-Xia; Lu, Cheng; Pan, Min-Hui

2014-05-12

Bombyx mori nucleopolyhedrovirus (BmNPV) ORF79 (Bm79) encodes an occlusion-derived virus (ODV)-specific envelope protein, which is a homologue of the per os infectivity factor 4 (PIF4) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). To investigate the role of ORF79 in the BmNPV life cycle, a Bm79 knockout virus (vBm(Bm79KO)) was constructed through homologous recombination in Escherichia coli. Viral DNA replication, budded virus (BV) production and polyhedra formation were unaffected by the absence of BM79. However, results of the larval bioassay demonstrated that the Bm79 deletion resulted in a complete loss of per os infection. Immunofluorescence analysis showed that BM79 localized at the innernuclear membrane of infected cells through its N-terminal sorting motif (SM). Further bimolecular fluorescence protein complementation and co-immunoprecipitation assays demonstrated the interaction of BM79 with PIF1, PIF2, PIF3 and ODV-E66. Thus, BM79 plays an important role in per os infection and is associated with the viral PIF complex of BmNPV. Copyright © 2014 Elsevier B.V. All rights reserved.

Palmitoylation targets AKAP79 protein to lipid rafts and promotes its regulation of calcium-sensitive adenylyl cyclase type 8.

PubMed

Delint-Ramirez, Ilse; Willoughby, Debbie; Hammond, Gerald R V; Hammond, Gerald V R; Ayling, Laura J; Cooper, Dermot M F

2011-09-23

PKA anchoring proteins (AKAPs) optimize the efficiency of cAMP signaling by clustering interacting partners. Recently, AKAP79 has been reported to directly bind to adenylyl cyclase type 8 (AC8) and to regulate its responsiveness to store-operated Ca(2+) entry (SOCE). Although AKAP79 is well targeted to the plasma membrane via phospholipid associations with three N-terminal polybasic regions, recent studies suggest that AKAP79 also has the potential to be palmitoylated, which may specifically allow it to target the lipid rafts where AC8 resides and is regulated by SOCE. In this study, we have addressed the role of palmitoylation of AKAP79 using a combination of pharmacological, mutagenesis, and cell biological approaches. We reveal that AKAP79 is palmitoylated via two cysteines in its N-terminal region. This palmitoylation plays a key role in targeting the AKAP to lipid rafts in HEK-293 cells. Mutation of the two critical cysteines results in exclusion of AKAP79 from lipid rafts and alterations in its membrane diffusion behavior. This is accompanied by a loss of the ability of AKAP79 to regulate SOCE-dependent AC8 activity in intact cells and decreased PKA-dependent phosphorylation of raft proteins, including AC8. We conclude that palmitoylation plays a key role in the targeting and action of AKAP79. This novel property of AKAP79 adds an unexpected regulatory and targeting option for AKAPs, which may be exploited in the cellular context.

HPRT mutations in V79 Chinese hamster cells induced by accelerated Ni, Au and Pb ions.

PubMed

Stoll, U; Barth, B; Scheerer, N; Schneider, E; Kiefer, J

1996-07-01

Mutation induction by accelerated heavy ions to 6-TG resistance (HPRT system) in V79 Chinese hamster cells was investigated with Ni (6-630 Me V/u), Au (2.2, 8.7 Me V/u) and Pb ions (11.6-980 Me V/u) corresponding to a LET range between 180 and 12895 ke V/microns. Most experiments could only be performed once due to technical limitations using accelerator beam times. Survival curves were exponential, mutation induction curves linear with fluence. From their slopes inactivation- and mutation-induction cross-sections were derived. If they are plotted versus LET, single, ion-specific curves are obtained. It is shown that other parameters like ion energy and effective charge play an important role. In the case of Au and Pb ions the cross-sections follow a common line, since these ions have nearly the same atomic weight, so that they should have similar spatial ionization patterns in matter at the same energies. Calculated RBEs were higher for mutation induction than for killing for all LETs.

Effective D-A-D type chromophore of fumaronitrile-core and terminal alkylated bithiophene for solution-processed small molecule organic solar cells.

PubMed

Nazim, M; Ameen, Sadia; Seo, Hyung-Kee; Shin, Hyung Shik

2015-06-12

A new and novel organic π-conjugated chromophore (named as RCNR) based on fumaronitrile-core acceptor and terminal alkylated bithiophene was designed, synthesized and utilized as an electron-donor material for the solution-processed fabrication of bulk-heterojunction (BHJ) small molecule organic solar cells (SMOSCs). The synthesized organic chromophore exhibited a broad absorption peak near green region and strong emission peak due to the presence of strong electron-withdrawing nature of two nitrile (-CN) groups of fumaronitrile acceptor. The highest occupied molecular orbital (HOMO) energy level of -5.82 eV and the lowest unoccupied molecular orbital (LUMO) energy level of -3.54 eV were estimated for RCNR due to the strong electron-accepting tendency of -CN groups. The fabricated SMOSC devices with RCNR:PC60BM (1:3, w/w) active layer exhibited the reasonable power conversion efficiency (PCE) of ~2.69% with high short-circuit current density (JSC) of ~9.68 mA/cm(2) and open circuit voltage (VOC) of ~0.79 V.

Effective D-A-D type chromophore of fumaronitrile-core and terminal alkylated bithiophene for solution-processed small molecule organic solar cells

PubMed Central

Nazim, M.; Ameen, Sadia; Seo, Hyung-Kee; Shin, Hyung Shik

2015-01-01

A new and novel organic π-conjugated chromophore (named as RCNR) based on fumaronitrile-core acceptor and terminal alkylated bithiophene was designed, synthesized and utilized as an electron-donor material for the solution-processed fabrication of bulk-heterojunction (BHJ) small molecule organic solar cells (SMOSCs). The synthesized organic chromophore exhibited a broad absorption peak near green region and strong emission peak due to the presence of strong electron-withdrawing nature of two nitrile (–CN) groups of fumaronitrile acceptor. The highest occupied molecular orbital (HOMO) energy level of –5.82 eV and the lowest unoccupied molecular orbital (LUMO) energy level of –3.54 eV were estimated for RCNR due to the strong electron-accepting tendency of –CN groups. The fabricated SMOSC devices with RCNR:PC60BM (1:3, w/w) active layer exhibited the reasonable power conversion efficiency (PCE) of ~2.69% with high short-circuit current density (JSC) of ~9.68 mA/cm2 and open circuit voltage (VOC) of ~0.79 V. PMID:26066557

Flavonoids from Heliotropium subulatum exudate and their evaluation for antioxidant, antineoplastic and cytotoxic activities II.

PubMed

Singh, Bharat; Sahu, Pooran M; Sharma, Ram A

2017-02-01

The flavonoids are the largest group of phenolic compounds isolated from a wide range of higher plants. These compounds work as antimicrobials, anti-insect agents and protect plants from other types of biotic and abiotic stresses. Various researchers have suggested that flavonoids possessed antioxidant, antineoplastic and cytotoxic activities. The main objective of this study was to test dichloromethane fraction of resinous exudate of Heliotropium subulatum for their antioxidant, antineoplastic and cytotoxic activities, as well as to search new antioxidant and antineoplastic agents for pharmaceutical formulations. Five flavonoids were isolated from resinous exudate of this plant species and screened for their in vitro and in vivo antioxidant models (DPPH radical scavenging, reducing power, superoxide anion scavenging, metal chelating scavenging systems, catalase and lipid peroxidation), antineoplastic (Sarcoma 180), and cytotoxic (Chinese hamster V79 cells) activities. Tricetin demonstrated maximum antioxidant activity against both in vitro and in vivo experimental systems while galangin exhibited maximum inhibition (78.35%) at a dose of 10 µg/kg/day against Sarcoma 180. Similarly, it was found that galangin also showed highest activity (21.1 ± 0.15%) at a concentration of 70 µg/ml to Chinese hamster V79 cells. The observed results suggest that tricetin has a potential to scavenge free radicals in both in vitro and in vivo models while the galangin could be considered as antitumor and cytotoxic agent.

Detection of a deuterium isotope effect in di- and trisubstituted alkylphenylnitrosoureas. An SCE study in Chinese hamster V79-E cells.

PubMed

Thust, R; Mendel, J; Bach, B; Schwarz, H

1985-06-01

The genotoxicity of 1-methyl-3-phenyl-1-nitrosourea (MPNU), 1-methyl-3-(p-chlorophenyl)-1-nitrosourea (C1-MPNU), 1-ethyl-3-phenyl-1-nitrosourea (EPNU), 1,3-dimethyl-3-phenyl-1-nitrosourea (DMPNU) and their derivatives substituted by deuterium in different positions was studied using sister chromatid exchange (SCE) induction in Chinese hamster V79-E cells. Deuterium substitution in the 1-methyl group of MPNU (MPNU-d3) and C1-MPNU (C1-MPNU-d3) diminished the SCE-inducing capacity by 20-30% and by 30-40% in DMPNU (DMPNU-d3B). There was no altered SCE activity detected when the phenyl group of MPNU (MPNU-d5) or the 3-methyl group of DMPNU (DMPNU-d3A) was deuterium labeled. No isotope effect was detected in deuterated EPNU derivatives, presumably due to the instability of these compounds. It is surmised that the easier delocalization of the positive charge in the deuterated alkyl diazonium ion causes a diminished reactivity and therefore influences the type and amount of DNA alkylation. Furthermore, the experiments with DMPNU and its derivatives revealed that, in contrast to mono- and disubstituted nitrosoureas, the biological activities of these very stable trisubstituted nitrosoureas are strongly influenced by a serum factor in the culture fluid.

Investigation of toxicity and mutagenicity of cold atmospheric argon plasma.

PubMed

Maisch, T; Bosserhoff, A K; Unger, P; Heider, J; Shimizu, T; Zimmermann, J L; Morfill, G E; Landthaler, M; Karrer, S

2017-04-01

Cold atmospheric argon plasma is recognized as a new contact free approach for the decrease of bacterial load on chronic wounds in patients. So far very limited data are available on its toxicity and mutagenicity on eukaryotic cells. Thus, the toxic/mutagenic potential of cold atmospheric argon plasma using the MicroPlaSter β ® , which has been used efficiently in humans treating chronic and acute wounds, was investigated using the XTT assay in keratinocytes and fibroblasts and the HGPRT (hypoxanthine guanine phosphoribosyl transferase) assay with V79 Chinese hamster cells. The tested clinical parameter of a 2 min cold atmospheric argon plasma treatment revealed no relevant toxicity on keratinocytes (viability: 76% ± 0.17%) and on fibroblasts (viability: 81.8 ± 0.10) after 72 hr as compared to the untreated controls. No mutagenicity was detected in the HGPRT assay with V79 cells even after repetitive CAP treatments of 2-10 min every 24 hr for up to 5 days. In contrast, UV-C irradiation of V79 cells, used as a positive control in the HGPRT test, led to DNA damage and mutagenic effects. Our findings indicate that cold atmospheric plasma using the MicroPlaSter β ® shows negligible effects on keratinocytes and fibroblasts but no mutagenic potential in the HGPRT assay, indicating a new contact free safe technology. Environ. Mol. Mutagen. 58:172-177, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

In vitro genotoxicity of asbestos substitutes induced by coupled stimulation of dissolved high-valence ions and oxide radicals.

PubMed

Huo, Tingting; Dong, Faqin; Deng, Jianjun; Zhang, Qingbi; Ye, Wei; Zhang, Wei; Wang, Pingping; Sun, Dongping

2017-08-01

The wide use of asbestos and its substitutes has given rise to studies on their possible harmful effects on human health and environment. However, their toxic effects remain unclear. The present study was aimed to disclose the coupled effects of dissolved high-valence ions and oxide radicals using the in vitro cytotoxicity and genotoxicity of chrysotile (CA), nano-SiO 2 (NS), ceramic fiber (CF), glass fiber (GF), and rock wool (RW) on Chinese hamster lung cells V79. All samples induced cell mortality correlated well with the chemical SiO 2 content of asbestos substitutes and the amount of dissolved Si. Alkali or alkaline earth metal elements relieved mortality of V79 cells; Al 2 O 3 reinforced toxicity of materials. Asbestos substitutes generated lasting, increasing amount of acellular ·OH which formed at the fiber surface at sites with loose/unsaturated bonds, as well as by catalytic reaction through dissolved iron. Accumulated mechanical and radical stimulation induced the intracellular reactive oxygen species (ROS) elevation, morphology change, and deviating trans-membrane ion flux. The cellular ROS appeared as NS > GF > CF ≈ CA > RW, consistent with cell mortality rather than with acellular ·OH generation. Chromosomal and DNA lesions in V79 cells were not directly associated with the cellular ROS, while influenced by dissolved high-valence irons in the co-culture medium. In conclusion, ions from short-time dissolution of dust samples and the generation of extracellular ·OH presented combined effects in the elevation of intracellular ROS, which further synergistically induced cytotoxicity and genotoxicity.

DOT1L histone methyltransferase regulates the expression of BCAT1 and is involved in sphere formation and cell migration of breast cancer cell lines.

PubMed

Oktyabri, Dulamsuren; Ishimura, Akihiko; Tange, Shoichiro; Terashima, Minoru; Suzuki, Takeshi

2016-04-01

DOT1L is a histone H3 lysine 79 (H3K79) methyltransferase mainly implicated in leukemia. Here we analyzed the function of DOT1L in breast cancer cells. The expression of DOT1L was up-regulated in malignant breast cancer tissues. Over-expression of DOT1L significantly increased the sphere formation and the cell migration activities of MCF7 breast cancer cell line. In contrast, knockdown of DOT1L reduced the cell migration activity of MDA-MB-231 breast cancer cell line. BCAT1, which encodes a branched-chain amino acid transaminase, was identified as one of the target genes controlled by DOT1L through the regulation of H3K79 methylation. Mechanistic investigation revealed that BCAT1 might be an important regulator responsible for DOT1L-mediated sphere formation and cell migration in breast cancer cells. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

eTumorType, An Algorithm of Discriminating Cancer Types for Circulating Tumor Cells or Cell-free DNAs in Blood.

PubMed

Zou, Jinfeng; Wang, Edwin

2017-04-01

With the technology development on detecting circulating tumor cells (CTCs) and cell-free DNAs (cfDNAs) in blood, serum, and plasma, non-invasive diagnosis of cancer becomes promising. A few studies reported good correlations between signals from tumor tissues and CTCs or cfDNAs, making it possible to detect cancers using CTCs and cfDNAs. However, the detection cannot tell which cancer types the person has. To meet these challenges, we developed an algorithm, eTumorType, to identify cancer types based on copy number variations (CNVs) of the cancer founding clone. eTumorType integrates cancer hallmark concepts and a few computational techniques such as stochastic gradient boosting, voting, centroid, and leading patterns. eTumorType has been trained and validated on a large dataset including 18 common cancer types and 5327 tumor samples. eTumorType produced high accuracies (0.86-0.96) and high recall rates (0.79-0.92) for predicting colon, brain, prostate, and kidney cancers. In addition, relatively high accuracies (0.78-0.92) and recall rates (0.58-0.95) have also been achieved for predicting ovarian, breast luminal, lung, endometrial, stomach, head and neck, leukemia, and skin cancers. These results suggest that eTumorType could be used for non-invasive diagnosis to determine cancer types based on CNVs of CTCs and cfDNAs. Copyright © 2017 Beijing Institute of Genomics, Chinese Academy of Sciences and Genetics Society of China. Production and hosting by Elsevier B.V. All rights reserved.

Radiobiological response of U251MG, CHO-K1 and V79 cell lines to accelerator-based boron neutron capture therapy

PubMed Central

Sato, Eisuke; Zaboronok, Alexander; Yamamoto, Tetsuya; Nakai, Kei; Taskaev, Sergey; Volkova, Olga; Mechetina, Ludmila; Taranin, Alexander; Kanygin, Vladimir; Isobe, Tomonori; Mathis, Bryan J; Matsumura, Akira

2018-01-01

Abstract In the current article, we provide in vitro efficacy evaluation of a unique accelerator-based neutron source, constructed at the Budker Institute of Nuclear Physics (Novosibirsk, Russian Federation), for boron neutron capture therapy (BNCT), which is particularly effective in the case of invasive cancers. U251MG, CHO-K1 and V79 cells were incubated and irradiated in various concentrations of boric acid with epithermal neutrons for 2–3 h in a plexiglass phantom, using 2.0 MeV proton energy and 1.5–3.0 mA proton current, resulting in a neutron fluence of 2.16 × 1012 cm−2. The survival curves of cells loaded with boron were normalized to those irradiated without boron (to exclude the influence of the fast neutron and gamma dose components) and fit to the linear–quadratic (LQ) model. Colony formation assays showed the following cell survival rates (means ± SDs): CHO-K1: 0.348 ± 0.069 (10 ppm), 0.058 ± 0.017 (20 ppm), 0.018 ± 0.005 (40 ppm); V79: 0.476 ± 0.160 (10 ppm), 0.346 ± 0.053 (20 ppm), 0.078 ± 0.015 (40 ppm); and U251MG: 0.311 ± 0.061 (10 ppm), 0.131 ± 0.022 (20 ppm), 0.020 ± 0.010 (40 ppm). The difference between treated cells and controls was significant in all cases (P < 0.01) and confirmed that the neutron source and irradiation regimen were sufficient for control over cell colony formation. We believe our study will serve as a model for ongoing in vitro experiments on neutron capture therapy to advance in this area for further development of accelerator-based BNCT into the clinical phase. PMID:29281044

Further study of inversion layer MOS solar cells

NASA Technical Reports Server (NTRS)

Ho, Fat Duen

1987-01-01

A group of inversion layer MOS solar cells has been fabricated. The highest value of open-circuit voltage obtained for the cells is 0.568V. One of the cells has produced a short-circuit current of 79.6 mA and an open-circuit voltage of 0.54V. It is estimated that the actual area AMO efficiency of this cell is 6.6 percent with an assumed value of 0.75 for its fill factor. Efforts made for fabricating an IL/MOS cell with reasonable efficiencies are reported. Future work for 4 sq cm IL cells and 25 sq cm IL cells is discussed.

Antimutagenic and antioxidant properties of the aqueous extracts of organic and conventional grapevine Vitis labrusca cv. Isabella leaves in V79 cells.

PubMed

Trindade, Cristiano; Bortolini, Giovana Vera; Costa, Bárbara Segalotto; Anghinoni, Joanna Carra; Guecheva, Temenouga Nikolova; Arias, Ximena; Césio, Maria Verónica; Heinzen, Horácio; Moura, Dinara Jaqueline; Saffi, Jenifer; Salvador, Mirian; Henriques, João Antonio Pêgas

2016-01-01

Grapes are one of the most commonly consumed fruit, in both fresh and processed forms; however, a significant amount is disposed of in the environment. Searching for a use of this waste, the antigenotoxic, antimutagenic, and antioxidant activities of aqueous extracts from organic and conventional Vitis labrusca leaves were determined using V79 cells as model. The antigenotoxic activity was analyzed by the alkaline comet assay using endonuclease III and formamidopyrimidine DNA glycosylase enzymes. The antimutagenic property was assessed through the micronucleus (MN) formation, and antioxidant activities were assessed using 2',7'-dichlorodihydrofluorescin diacetate (DCFH-DA) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH(●)) radical scavenging, as well as with superoxide dismutase (SOD) and catalase (CAT) activity assays. In addition, phenolic content and ascorbic acid levels of both extracts were determined. Data showed that both organic and conventional grapevine leaves extracts possessed antigenotoxic and antimutagenic properties. The extract of organic leaves significantly reduced intracellular reactive oxygen species (ROS) levels in V79 cells, and displayed greater ability for DPPH(●) scavenging and higher SOD and CAT activities than extract from conventional leaves. Further, the extract from organic leaves contained higher phenolic and ascorbic acid concentrations. In summary, extracts from organic and conventional grape leaves induced important in vitro biological effects.

Interlaboratory studies with the Chinese hamster V79 cell metabolic cooperation assay to detect tumor-promoting agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohrman, J.S.; Burg, J.R.; Elmore, E.

1988-01-01

Three laboratories participated in an interlaboratory study to evaluate the usefulness of the Chinese hamster V79 cell metabolic cooperation assay to predict the tumor-promoting activity of selected chemical. Twenty-three chemicals of different chemical structures (phorbol esters, barbiturates, phenols, artificial sweeteners, alkanes, and peroxides) were chosen for testing based on in vivo promotion activities, as reported in the literature. Assay protocols and materials were standardized, and the chemicals were coded to facilitate unbiased evaluation. A chemical was tested only once in each laboratory, with one of the three laboratories testing only 15 out of 23 chemicals. Dunnett's test was used formore » statistical analysis. Chemicals were scored as positive (at least two concentration levels statistically different than control), equivocal (only one concentration statistically different), or negative. For 15 chemicals tested in all three laboratories, there was complete agreement among the laboratories for nine chemicals. For the 23 chemicals tested in only two laboratories, there was agreement on 16 chemicals. With the exception of the peroxides and alkanes, the metabolic cooperation data were in general agreement with in vivo data. However, an overall evaluation of the V79 cell system for predicting in vivo promotion activity was difficult because of the organ specificity of certain chemicals and/or the limited number of adequately tested nonpromoting chemicals.« less

First isolation of a new type of human adenovirus (genotype 79), species Human mastadenovirus B (B2) from sewage water in Japan.

PubMed

Yoshitomi, Hideaki; Sera, Nobuyuki; Gonzalez, Gabriel; Hanaoka, Nozomu; Fujimoto, Tsuguto

2017-07-01

Human mastadenoviruses (HAdVs) are highly infectious viral pathogens that survive for prolonged periods in environmental waters. We monitored the presence of HAdVs in sewage waters between April 2014 and March 2015. A total of 27 adenoviral strains were detected in 75% (18/24 in occasion-base) of 24 wastewater collected samples. We identified the types of the strains as HAdV-C2 (n = 5), HAdV-A31 (5), HAdV-C1 (4), HAdV-B3 (4), HAdV-C5 (4), HAdV-B11 (2), P11H34F11 (2), and HAdV-D56 (1). The complete genome sequence of one P11H34F11 (strain T150125) was determined by next-generation sequencing and compared to other genome sequences of HAdV-B strains. The comparisons revealed evidence of a recombination event with breaking point in the hexon encoding region, which evidenced high similarity to HAdV-B34, while half of the rest of the genome showed similarity to HAdV-B11, including regions encoding fiber and E3 region proteins. The penton base encoding region seemed to be a recombinant product of HAdV-B14, -34; however, it was evidenced to be divergent to both as a novel type despite showing low bootstrap to support a new clade. We propose T150125 (P11H34F11) is a strain of a novel genotype, HAdV-79. These results support the usefulness of environmental surveillance approaches to monitor circulating HAdVs including novel types. © 2016 Wiley Periodicals, Inc.

Identification of a Secondary Promoter within the Human B Cell Receptor Component Gene hCD79b*

PubMed Central

Yoo, Eung Jae; Cooke, Nancy E.; Liebhaber, Stephen A.

2013-01-01

The human B cell-specific protein, CD79b (also known as Igβ and B29) constitutes an essential signal transduction component of the B cell receptor. Although its function is central to the triggering of B cell terminal differentiation in response to antigen stimulation, the transcriptional determinants that control CD79b gene expression remain poorly defined. In the present study, we explored these determinants using a series of hCD79b transgenic mouse models. Remarkably, we observed that the previously described hCD79b promoter along with its associated enhancer elements and first exon could be deleted without appreciable loss of hCD79b transcriptional activity or tissue specificity. In this deletion setting, a secondary promoter located within exon 2 maintained full levels and specificity of hCD79b transcription. Of note, this secondary promoter was also active, albeit at lower levels, in the wild-type hCD79b locus. The activity of the secondary promoter was dependent on the action(s) of a conserved sequence element mapping to a chromatin DNase I hypersensitive site located within intron 1. mRNA generated from this secondary promoter is predicted to encode an Igβ protein lacking a signal sequence and thus unable to serve normal B cell receptor function. Although the physiologic role of the hCD79b secondary promoter and its encoded protein remain unclear, the current data suggest that it has the capacity to play a role in normal as well as pathologic states in B cell proliferation and function. PMID:23649625

AM1-receptor-dependent protection by intermedin of human vascular and cardiac non-vascular cells from ischaemia–reperfusion injury

PubMed Central

Bell, David; Campbell, Malcolm; Ferguson, Matthew; Sayers, Leah; Donaghy, Liz; O'Regan, Anna; Jewhurst, Victoria; Harbinson, Mark

2012-01-01

Intermedin (IMD) protects rodent heart and vasculature from oxidative stress and ischaemia. Less is known about distribution of IMD and its receptors and the potential for similar protection in man. Expression of IMD and receptor components were studied in human aortic endothelium cells (HAECs), smooth muscle cells (HASMCs), cardiac microvascular endothelium cells (HMVECs) and fibroblasts (v-HCFs). Receptor subtype involvement in protection by IMD against injury by hydrogen peroxide (H2O2, 1 mmol l−1) and simulated ischaemia and reperfusion were investigated using receptor component-specific siRNAs. IMD and CRLR, RAMP1, RAMP2 and RAMP3 were expressed in all cell types. When cells were treated with 1 nmol l−1 IMD during exposure to 1 mmol l−1 H2O2 for 4 h, viability was greater vs. H2O2 alone (P < 0.05 for all cell types). Viabilities under 6 h simulated ischaemia differed (P < 0.05) in the absence and presence of 1 nmol l−1 IMD: HAECs 63% and 85%; HMVECs 51% and 68%; v-HCFs 42% and 96%. IMD 1 nmol l−1 present throughout ischaemia (3 h) and reperfusion (1 h) attenuated injury (P < 0.05): viabilities were 95%, 74% and 82% for HAECs, HMVECs and v-HCFs, respectively, relative to those in the absence of IMD (62%, 35%, 32%, respectively). When IMD 1 nmol l−1 was present during reperfusion only, protection was still evident (P < 0.05, 79%, 55%, 48%, respectively). Cytoskeletal disruption and protein carbonyl formation followed similar patterns. Pre-treatment (4 days) of HAECs with CRLR or RAMP2, but not RAMP1 or RAMP3, siRNAs abolished protection by IMD (1 nmol l−1) against ischaemia–reperfusion injury. IMD protects human vascular and cardiac non-vascular cells from oxidative stress and ischaemia–reperfusion, predominantly via AM1 receptors. PMID:22183724

Investigation of styrene in the liver perfusion/cell culture system. No indication of styrene-7,8-oxide as the principal mutagenic metabolite produced by the intact rat liver.

PubMed

Beije, B; Jenssen, D

1982-03-01

Mutagenic effect of styrene and styrene-7,8-oxide was studied with the isolated perfused rat liver as metabolizing system and Chinese hamster V79 cells as genetic target cells. Styrene-7,8-oxide which is mutagenic per se was rapidly metabolized by the perfused rat liver. Thus no mutagenic effect was detected neither in the perfusion medium nor in the bile. However when styrene was added to the perfusion system, an increase in V79 mutants was observed regardless of where in the circulating perfusion medium the V79 cells were placed: the same effect was obtained with V79 cells close to the liver as well as at a distance from the liver. No mutagenic effect was observed in the bile. Simultaneous analysis of the styrene-7,8-oxide concentration in the perfusion medium, suggest that this metabolite is not the cause of the mutagenic effect observed during perfusion with styrene. The effect of the two test compounds on some liver functions was also studied. Both styrene and styrene-7,8-oxide changed the bile flow without affecting bile acid secretion: styrene caused a reduction in bile flow as compared to control perfusions and styrene-7,8-oxide increased the bile flow. Styrene, but not styrene-7,8-oxide, reduced gluconeogenesis from lactate. Styrene had no effect on the liver's capacity to incorporate amino acids into plasma proteins, whereas styrene-7,8-oxide reduced the amino acid incorporation. The microsomal cytochrome P-450 content was not affected by the two test compounds. No alteration in microsomal N- and C-oxygenation of N,N-dimethylaniline (DMA) was observed with styrene-7,8-oxide or the lower styrene dose used (240 mumol), whereas the higher styrene concentration (480 mumol) reduced N-oxygenation and thus also the total DNA metabolism. It is suggested that the results on styrene and styrene-7,8-oxide found here using the liver perfusion/cell culture system mimic the metabolism expected to be found in the intact animal, thus indicating that styrene-7,8-oxide is not the principal mutagenic metabolite of styrene in vivo.

Bcl-2-independent induction of apoptosis by neuropeptide receptor antagonist in human small cell lung carcinoma cells.

PubMed

Matsumoto, Y; Kawatani, M; Simizu, S; Tanaka, T; Takada, M; Imoto, M

2000-01-01

The broad-spectrum antagonist of neuropeptide receptor, [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P, induced apoptosis selectively in human small cell lung carcinoma (SCLC) cells, which express gastrin-releasing peptide receptor, but not in other types of tumor cells as well as normal cells. The addition of gastrin-releasing peptide or bombesin and the inhibitor of caspase-3 suppressed [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P-induced apoptosis. Moreover, [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P-induced apoptosis was not suppressed by Bcl-2 over-expression. Thus, blockage of gastrin-releasing peptide receptor-mediated signaling may provide a novel therapeutic option in SCLC which has become resistant to conventional chemotherapeutic agents.

A cytotoxic substance from Sangre de Grado.

PubMed

Itokawa, H; Ichihara, Y; Mochizuki, M; Enomori, T; Morita, H; Shirota, O; Inamatsu, M; Takeya, K

1991-04-01

Taspine has been isolated as a cytotoxic substance from Sangre de Grado, sap of Croton palanostigma (Euphorbiaceae), by bioassay guided fractionation. The cytotoxicity (IC50) of taspine was found to be 0.39 microgram/ml against KB cells and 0.17 microgram/ml against V-79 cells.

Mutagenic and lethal effects of (5-/sup 125/I)lodo-2'-deoxyuridine incorporated into DNA of mammalian cells, and their RBEs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyazaki, N.; Fujiwara, Y.

1981-12-01

Decay of /sup 125/I unifilarly incorporated as 5-iodo-2'-deoxyuridine (IdUrd) into DNA of V79 Chinese hamster cells was approximately an order of magnitude more effective in inducing both 6-thioguanine-resistant mutation and cell inactivation than external X rays under equivalent conditions. RBEs of mutation and killing induced by /sup 125/I decays, compared with 170-kVp X rays of low LET, were approx. = 11 for mutation (ratio of the induction rate in frequency/rad = 11.3 X 10/sup -7/ (/sup 125/I)/100 X 10/sup -7/ (X rays at -79/sup o/C)) and approx. = 10 for cell inactivation (D/sub 0/ ratio = 505 rad (X raysmore » at -79/sup o/C)/52 rad (/sup 125/I)). These RBE values may well exceed the reported maximum values for high-LET radiation in the LET range of 80-110 keV/..mu..m, suggesting that the Auger effect is different from the high-LET radiation effect alone. Thus these biological consequences arise not only from radiation effects of Auger electrons on the immediate vicinity in DNA, but also from the nonionogenic effect through charge transfer processes. In addition, higher inductions of mutation and killing by external X rays in unifilarly IdUrd-substituted cells than in ordinal cells were observed, suggesting a possible involvement of X-ray-induced Auger phenomenon in iodine in DNA.« less

Protective effect of boric acid on lead- and cadmium-induced genotoxicity in V79 cells.

PubMed

Ustündağ, Aylin; Behm, Claudia; Föllmann, Wolfram; Duydu, Yalçin; Degen, Gisela H

2014-06-01

The toxic heavy metals cadmium (Cd) and lead (Pb) are important environmental pollutants which can cause serious damage to human health. As the metal ions (Cd(2+) and Pb(2+)) accumulate in the organism, there is special concern regarding chronic toxicity and damage to the genetic material. Metal-induced genotoxicity has been attributed to indirect mechanisms, such as induction of oxidative stress and interference with DNA repair. Boron is a naturally occurring element and considered to be an essential micronutrient, although the cellular activities of boron compounds remain largely unexplored. The present study has been conducted to evaluate potential protective effects of boric acid (BA) against genotoxicity induced by cadmium chloride (CdCl2) and lead chloride (PbCl2) in V79 cell cultures. Cytotoxicity assays (neutral red uptake and cell titer blue assay) served to determine suitable concentrations for subsequent genotoxicity assays. Chromosomal damage and DNA strand breaks were assessed by micronucleus tests and comet assays. Both PbCl2 and CdCl2 (at 3, 5 and 10 µM) were shown to induce concentration-dependent increases in micronucleus frequencies and DNA strand breaks in V79 cells. BA itself was not cytotoxic (up to 300 µM) and showed no genotoxic effects. Pretreatment of cells with low levels of BA (2.5 and 10 µM) was found to strongly reduce the genotoxic effects of the tested metals. Based on the findings of this in vitro study, it can be suggested that boron provides an efficient protection against the induction of DNA strand breaks and micronuclei by lead and cadmium. Further studies on the underlying mechanisms for the protective effect of boron are needed.

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

PubMed Central

Ahlberg, Sebastian; Antonopulos, Alexandra; Diendorf, Jörg; Dringen, Ralf; Flöck, Rebekka; Goedecke, Wolfgang; Graf, Christina; Haberl, Nadine; Helmlinger, Jens; Herzog, Fabian; Heuer, Frederike; Hirn, Stephanie; Johannes, Christian; Kittler, Stefanie; Köller, Manfred; Korn, Katrin; Kreyling, Wolfgang G; Krombach, Fritz; Lademann, Jürgen; Loza, Kateryna; Luther, Eva M; Malissek, Marcelina; Meinke, Martina C; Nordmeyer, Daniel; Pailliart, Anne; Raabe, Jörg; Rancan, Fiorenza; Rothen-Rutishauser, Barbara; Rühl, Eckart; Schleh, Carsten; Seibel, Andreas; Sengstock, Christina; Treuel, Lennart; Vogt, Annika; Weber, Katrin; Zellner, Reinhard

2014-01-01

Summary PVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm, a hydrodynamic diameter of 120 nm and a zeta potential of −20 mV were prepared and investigated with regard to their biological activity. This review summarizes the physicochemical properties (dissolution, protein adsorption, dispersability) of these nanoparticles and the cellular consequences of the exposure of a broad range of biological test systems to this defined type of silver nanoparticles. Silver nanoparticles dissolve in water in the presence of oxygen. In addition, in biological media (i.e., in the presence of proteins) the surface of silver nanoparticles is rapidly coated by a protein corona that influences their physicochemical and biological properties including cellular uptake. Silver nanoparticles are taken up by cell-type specific endocytosis pathways as demonstrated for hMSC, primary T-cells, primary monocytes, and astrocytes. A visualization of particles inside cells is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM analysis. By staining organelles, their localization inside the cell can be additionally determined. While primary brain astrocytes are shown to be fairly tolerant toward silver nanoparticles, silver nanoparticles induce the formation of DNA double-strand-breaks (DSB) and lead to chromosomal aberrations and sister-chromatid exchanges in Chinese hamster fibroblast cell lines (CHO9, K1, V79B). An exposure of rats to silver nanoparticles in vivo induced a moderate pulmonary toxicity, however, only at rather high concentrations. The same was found in precision-cut lung slices of rats in which silver nanoparticles remained mainly at the tissue surface. In a human 3D triple-cell culture model consisting of three cell types (alveolar epithelial cells, macrophages, and dendritic cells), adverse effects were also only found at high silver concentrations. The silver ions that are released from silver nanoparticles may be harmful to skin with disrupted barrier (e.g., wounds) and induce oxidative stress in skin cells (HaCaT). In conclusion, the data obtained on the effects of this well-defined type of silver nanoparticles on various biological systems clearly demonstrate that cell-type specific properties as well as experimental conditions determine the biocompatibility of and the cellular responses to an exposure with silver nanoparticles. PMID:25383306

Methods of improving the efficiency of photovoltaic cells. [including X ray analysis

NASA Technical Reports Server (NTRS)

Loferski, J. J.; Roessler, B.; Crisman, E. E.; Chen, L. Y.; Kaul, R.

1974-01-01

Work on aluminum-alloyed silicon grating cells is continued. Optimization of the geometry (grating line width and spacing) confirms the analysis of such cells. A 1 sq cm grating cell was fabricated and its i-V characteristic was measured under an AMO solar simulator. It is found that the efficiency of this cell would be about 7.9%, if it were covered by the usual antireflection coating. The surface of the cell is not covered by a diffused junction. The response is blue shifted; the current is somewhat higher than that produced by a commercial Si cell. However, the open circuit voltage is low, and attempts to optimize the open circuit voltage of the aluminum-alloy junctions are described. A preliminary X-ray topographic examination of GaAs specimens of the type commonly used to make solar cells is studied. The X-ray study shows that the wafers are filled with regions having strain gradients, possibly caused by precipitates. It is possible that a correlation exists between the presence of low mechanical perfection and minority carrier diffusion lengths of GaAs crystals.

Immune system cells in healthy ferrets: an immunohistochemical study.

PubMed

Vidaña, B; Majó, N; Pérez, M; Montoya, M; Martorell, J; Martínez, J

2014-07-01

The ferret has emerged as an excellent animal model to characterize several physiologic and pathologic conditions. The distribution and characterization of different types of immune system cells were studied in healthy ferret tissues. Eight primary antibodies were tested for immunohistochemistry in formalin-fixed tissues: anti-CD3, anti-CD79α, anti-CD20, anti-HLA-DR, anti-lysozyme, anti-CD163, anti-SWC3, and anti-Mac387. The anti-CD3 antibody labeled T cells mainly in interfollicular and paracortical areas of lymph nodes, cortex and thymic medulla, and periarteriolar lymphoid sheaths in the spleen. The anti-CD79α and anti-CD20 antibodies immunolabeled B cells located in lymphoid follicles at lymph nodes, spleen, and Peyer patches. The CD79α and CD20 antibodies also labeled cells with nonlymphoid morphology in atypical B-cell locations. The anti-HLA-DR antibody labeled macrophages, some populations of B and T lymphocytes, and different populations of dendritic cells in lymph nodes, Peyer patches, spleen, and thymus. The anti-lysozyme antibody immunolabeled macrophages in the liver, lymph nodes, spleen, and thymus. The Mac-387, CD163, and SWC3 antibodies did not show any positive reaction in formalin-fixed or frozen tissues. To elucidate the origin of the uncommon CD79α/CD20 positive cells, a double immunohistochemistry was carried out using the anti-HLA-DR + the anti-CD79α, the anti-HLA-DR + the anti-CD20, and the anti-lysozyme + the anti-CD79α antibodies. Double labeling was mainly observed when the anti-HLA-DR + the anti-CD79α antibodies were combined. The immunohistologic characterization and distribution of these immune system cells in healthy ferret tissues should be of value in future comparative studies of diseases in ferrets. © The Author(s) 2013.

Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro.

PubMed

Rao, B S S; Shanbhoge, R; Rao, B N; Adiga, S K; Upadhya, D; Aithal, B K; Kumar, M R S

2009-04-01

This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 microg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 microg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant (P < 0.05-0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 microg/mL) before exposure to different doses of gamma radiation, that is, 0.5-4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential.

Thin-film silicon for flexible metal-air batteries.

PubMed

Garamoun, Ahmed; Schubert, Markus B; Werner, Jürgen H

2014-12-01

Due to its high energy density, theoretical studies propose silicon as a promising candidate material for metal-air batteries. Herein, for the first time, experimental results detail the use of n-type doped amorphous silicon and silicon carbide as fuel in Si-air batteries. Thin-film silicon is particularly interesting for flexible and rolled batteries with high specific energies. Our Si-air batteries exhibit a specific capacity of 269 Ah kg(-1) and an average cell voltage of 0.85 V at a discharge current density of 7.9 μA cm(-2) , corresponding to a specific energy of 229 Wh kg(-1) . Favorably in terms of safety, low concentrated alkaline solution serves as electrolyte. Discharging of the Si-air cells continues as long as there is silicon available for oxidation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Production of 13S-hydroxy-9(Z)-octadecenoic acid from linoleic acid by whole recombinant cells expressing linoleate 13-hydratase from Lactobacillus acidophilus.

PubMed

Park, Ji-Young; Lee, Seon-Hwa; Kim, Kyoung-Rok; Park, Jin-Byung; Oh, Deok-Kun

2015-08-20

Linoleate 13-hydratase from Lactobacillus acidophilus LMG 11470 converted linoleic acid to hydroxyl fatty acid, which was identified as 13S-hydroxy-9(Z)-octadecenoic acid (13-HOD) by GC-MS and NMR. The expression of linoleate 13-hydratase gene in Escherichia coli was maximized by using pACYC plasmid and super optimal broth with catabolite repression (SOC) medium containing 40mM Mg(2+). To optimize induction conditions, recombinant cells were cultivated at 37°C, 1mM isopropyl-β-d-thiogalactopyranoside was added at 2h, and the culture was further incubated at 16°C for 18h. Recombinant cells expressing linoleate 13-hydratase from L. acidophilus were obtained under the optimized expression conditions and used for 13-HOD production from linoleic acid. The optimal reaction conditions were pH 6.0, 40°C, 0.25% (v/v) Tween 40, 25gl(-1) cells, and 100gl(-1) linoleic acid, and under these conditions, whole recombinant cells produced 79gl(-1) 13-HOD for 3h with a conversion yield of 79% (w/w), a volumetric productivity of 26.3gl(-1)h(-1), and a specific productivity of 1.05g g-cells(-1)h(-1). To the best of our knowledge, the recombinant cells produced hydroxy fatty acid with the highest concentration and productivity reported so far. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Mitotic accumulation of dimethylated lysine 79 of histone H3 is important for maintaining genome integrity during mitosis in human cells.

PubMed

Guppy, Brent J; McManus, Kirk J

2015-02-01

The loss of genome stability is an early event that drives the development and progression of virtually all tumor types. Recent studies have revealed that certain histone post-translational modifications exhibit dynamic and global increases in abundance that coincide with mitosis and exhibit essential roles in maintaining genomic stability. Histone H2B ubiquitination at lysine 120 (H2Bub1) is regulated by RNF20, an E3 ubiquitin ligase that is altered in many tumor types. Through an evolutionarily conserved trans-histone pathway, H2Bub1 is an essential prerequisite for subsequent downstream dimethylation events at lysines 4 (H3K4me2) and 79 (H3K79me2) of histone H3. Although the role that RNF20 plays in tumorigenesis has garnered much attention, the downstream components of the trans-histone pathway, H3K4me2 and H3K79me2, and their potential contributions to genome stability remain largely overlooked. In this study, we employ single-cell imaging and biochemical approaches to investigate the spatial and temporal patterning of RNF20, H2Bub1, H3K4me2, and H3K79me2 throughout the cell cycle, with a particular focus on mitosis. We show that H2Bub1, H3K4me2, and H3K79me2 exhibit distinct temporal progression patterns throughout the cell cycle. Most notably, we demonstrate that H3K79me2 is a highly dynamic histone post-translational modification that reaches maximal abundance during mitosis in an H2Bub1-independent manner. Using RNAi and chemical genetic approaches, we identify DOT1L as a histone methyltransferase required for the mitotic-associated increases in H3K79me2. We also demonstrate that the loss of mitotic H3K79me2 levels correlates with increases in chromosome numbers and increases in mitotic defects. Collectively, these data suggest that H3K79me2 dynamics during mitosis are normally required to maintain genome stability and further implicate the loss of H3K79me2 during mitosis as a pathogenic event that contributes to the development and progression of tumors. Copyright © 2015 by the Genetics Society of America.

Genotoxic and mutagenic properties of Bauhinia platypetala extract, a traditional Brazilian medicinal plant.

PubMed

Santos, Francisco José Borges Dos; Moura, Dinara Jaqueline; Péres, Valéria Flores; Sperotto, Angelo Regis de Moura; Caramão, Elina Bastos; Cavalcante, Ana Amélia de Carvalho Melo; Saffi, Jenifer

2012-12-18

Bauhinia platypetala Burch. is a traditionally used Brazilian medicinal plant, although no evidence in the literature substantiates the safety of its use. The aim of this study was to investigate the safety of the ethanolic extract and the ethereal fraction of B. platypetala leaves. The identification of chemical compounds from the B. platypetala ethanolic extract and its ethereal fraction was performed by GC/MS and ESI-MS/MS. The plant's toxicological, cytotoxic, mutagenic and genotoxic properties were determined in Saccharomyces cerevisiae strains and V79 cell culture by survival assays and comet assay. The major compound identified in the B. platypetala ethanolic extract is palmitic acid, kaempferitirin and quercitrin, while the B. platypetala ethereal fraction was found to be rich in phytol, gamma-sitosterol and vitamin E. Moreover, the results indicated that the B. platypetala ethanolic extract has an anti-oxidative effect against H(2)O(2) in yeast. In addition, the B. platypetala ethanolic extract did not induce mutagenic effects on the S. cerevisiae N123 strain, but the ethereal fraction of B. platypetala at higher concentrations (250-500 μg/mL) induced cytotoxicity and mutagenicity. A slight cytotoxic effect was observed in mammalian V79 cells; however, both the B. platypetala ethanolic extract and its ethereal fraction were able to induce DNA strand breaks in V79 cells, as detected by the alkaline comet assay. The B. platypetala ethanolic extract has antioxidant action and showed absence of mutagenic effects in yeast S. cerevisiae. On the other hand B. platypetala ethereal fraction is mutagenic and does not show antioxidant activity in yeast. In mammalian cells B. platypetala ethanolic extract and it's ethereal fraction induce cyotoxic and genotoxic action. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Protective effect of N-acetyl-L-cysteine against disulfiram-induced oxidative stress and apoptosis in V79 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grosicka-Maciag, Emilia; Kurpios-Piec, Dagmara; Grzela, Tomasz

2010-11-01

This work investigated the effect of N-acetyl-L-cysteine (NAC) on disulfiram (DSF) induced oxidative stress in Chinese hamster fibroblast cells (V79). An increase in oxidative stress induced by DSF was observed up to a 200 {mu}M concentration. It was evidenced by a statistically significant increase of both GSH{sub t} and GSSG levels, as well as elevated protein carbonyl (PC) content. There was no increase in lipid peroxidation (measured as TBARS). DSF increased CAT activity, but did not change SOD1 and SOD2 activities. Analysis of GSH related enzymes showed that DSF significantly increased GR activity, did not change Se-dependent GPx, but statisticallymore » significantly decreased non-Se-dependent GPx activity. DSF showed also pro-apoptotic activity. NAC alone did not produce any significant changes, besides an increase of GSH{sub t} level, in any of the variables measured. However, pre-treatment of cells with NAC ameliorated DSF-induced changes. NAC pre-treatment restored the viability of DSF-treated cells evaluated by Trypan blue exclusion assay and MTT test, GSSG level, and protein carbonyl content to the control values as well as it reduced pro-apoptotic activity of DSF. The increase of CAT and GR activity was not reversed. Activity of both GPx was significantly increased compared to their values after DSF treatment. In conclusion, oxidative properties are at least partially attributable to the cellular effects of disulfiram and mechanisms induced by NAC pre-treatment may lower or even abolish the observed effects. These observations illustrate the importance of the initial cellular redox state in terms of cell response to disulfiram exposure. -- Research Highlights: {yields}This report explores biological properties of disulfiram under a condition of modulated intra-cellular GSH level. It shows a protective role of N-acetyl-L-cysteine in V79 cells exposed to disulfiram (in GSH metabolism as well as in changes of antioxidant enzyme activity).« less

Protection of ionizing radiation-induced cytogenetic damage by hydroalcoholic extract of Cynodon dactylon in Chinese hamster lung fibroblast cells and human peripheral blood lymphocytes.

PubMed

Rao, Bola Sadashiva Satish; Upadhya, Dinesh; Adiga, Satish Kumar

2008-01-01

The radiomodulatory potential of hydroalcoholic extract of a medicinal plant Cynodon dactylon (family: Poaceae) against radiation-induced cytogenetic damage was analyzed using Chinese hamster lung fibroblast (V79) cells and human peripheral blood lymphocytes (HPBLs) growing in vitro. Induction of micronuclei was used as an index of cytogenetic damage, evaluated in cytokinesis blocked binucleate cells. The hydroalcoholic Cynodon dactylon extract (CDE) rendered protection against the radiation-induced DNA damage, as evidenced by the significant (p<0.001) reduction in micronucleated binucleate cells (MNBNC%) after various doses of CDE treatment in V79 cells and HPBLs. The optimum dose of CDE (40 and 50 microg/ml in HPBLs and V79 cells, respectively) with the greatest reduction in micronuclei was further used in combination with various doses of gamma radiation (0.5, 1, 2, 3, and 4 Gy) exposed 1 h after CDE treatment. A linear dose-dependent MNBNC% increase in radiation alone group was observed, while 40/50 microg/ml CDE significantly resulted in the reduction of MNBNC%, compared to the respective radiation alone groups. CDE resulted in a dose-dependent increase in free radical scavenging ability against various free radicals, viz., 2, 2-diphenyl-2-picryl-hydrazyl (DPPH); 2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS); superoxide anion (O2*-); hydroxyl radical (OH*) and nitric oxide radical (NO*) generated in vitro. Also, an excellent (70%) inhibition of lipid peroxidation in vitro was observed at a dose of 300 microg/ml CDE, attaining the saturation point at higher doses. The present findings demonstrated the radioprotective effect of CDE, also rendering protection against radiation-induced genomic instability and DNA damage. The observed radioprotective effect may be partly attributed to the free radical scavenging and antilipid peroxidative potential of CDE.

Determine the yield of micronucleated cells in primary human fibroblasts exposed to focused soft X-rays.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kevin M. Prise

This project was a small part of a larger collaborative study headed by Dr Aloke Chatterjee, (Lawrence Berkeley National Laboratory) and including Drs Les Braby, John Ford (Texas A&M) and Kathy Held (MGH Boston), which was developing an integrated theoretical and experimental model of the radiation-induced bystander response. Our part of the study has been to determine the effectiveness of soft X-rays at inducing chromosomal damage under conditions of direct and bystander exposure. The aim was to compare this with the effectiveness of the low energy 60 kV electron microbeam available at Texas A&M. Previous studies have been performed withmore » primary human fibroblasts measuring micronuclei formation to determine the relative yields of direct versus bystander mediated micronuclei formation after cells were individually irradiated utilizing our novel focused soft X-ray microprobe, which is capable of producing localized submicron beams of carbon-K (278 eV) X-rays. Only a brief overview is given here as the study has been published in several papers. Our original hypothesis was to study yields of bystander-induced micronucleated cells in both wild-type and mutant fibroblast from mouse embryo fibroblasts. Difficulties with the level of background micronuclei in the MEFs prevented systematic studies of bystander responses in the laboratories involved in the collaboration. We then performed these studies with AG1522 primary human fibroblast cells using a siRNA approach developed by John Ford at Texas A&M to knock down DNA PKcs in the first instance. Our soft X-ray source has been in routine use for carbon-K X-rays and is now available with Aluminium-K (1.49 keV) and titanium-K (4.5 keV), although the dose-rate from titanium is still too low at present for most experiments, where large numbers of cells need to be exposed. A separately funded project developed a new soft X-ray microprobe which will give much greater flexibility for changing energies and giving high dose-rates for exposures (See DE-FG02-01ER63236). However, we performed pilot studies measuring bystander responses with titanium-K. To date we have performed studies with V79 cells measuring cell survival as an endpoint and are starting studies in our human fibroblasts to measure micronuclei yields. A significant bystander response is observed in the V79 cells under conditions where only a single cell within a population was irradiated either with carbon-K or titanium-K X-rays. Typically around 10% cell killing is observed under these conditions. These studies are now being extended to measure micronuclei yields in the AG1522 cells under direct and bystander conditions. Our work has suggested that the yield of micronuclei in fibroblasts exposed to soft X-rays may be reduced in comparison to conventional X-ray exposures (Prise et al., 2003). Although further studies are required to confirm this using a range of scoring times.« less

5-Fluorouracil, colchicine, benzo[a]pyrene and cytosine arabinoside tested in the in vitro mammalian cell micronucleus test (MNvit) in Chinese hamster V79 cells at Covance Laboratories, Harrogate, UK in support of OECD draft Test Guideline 487.

PubMed

Whitwell, James; Fowler, Paul; Allars, Sarah; Jenner, Karen; Lloyd, Melvyn; Wood, Debbie; Smith, Katie; Young, Jamie; Jeffrey, Laura; Kirkland, David

2010-10-29

The reference genotoxic agents 5-fluorouracil (a nucleoside analogue, characterised by a steep dose response profile), colchicine (an aneugen that inhibits tubulin polymerisation), benzo[a]pyrene (a polycyclic aromatic hydrocarbon requiring metabolic activation) and cytosine arabinoside (a nucleoside analogue that inhibits the gap-filling step of excision repair) were tested in the in vitro micronucleus assay using the Chinese hamster V79 cell line at Covance Laboratories, Harrogate, UK. All chemicals were treated in the absence and presence of cytokinesis block (via addition of cytochalasin B) with this work forming part of a collaborative evaluation of the toxicity measures recommended in the draft OECD Test Guideline 487 on the In Vitro Mammalian Cell Micronucleus Test (MNvit). The toxicity measures used, detecting a possible combination of both cytostasis and cell death (though not cell death directly), were relative population doubling, relative increase in cell counts and relative cell counts for treatments in the absence of cytokinesis block, and replication index in the presence of cytokinesis block. All of the chemicals tested either gave marked increases in the percentage of micronucleated cells with and without cytokinesis block, or did not induce micronuclei at concentrations giving approximately 50-60% toxicity (cytostasis and cell death) or less by all of the toxicity measures used. The outcome from this series of tests supports the use of relative increase in cell counts and relative population doubling, as well as relative cell counts, as appropriate measures of cytotoxicity for the non-cytokinesis blocked in vitro micronucleus assay. Copyright © 2010 Elsevier B.V. All rights reserved.

Novel thermal-sensitive hydrogel enhances both humoral and cell-mediated immune responses by intranasal vaccine delivery.

PubMed

Wu, Youbin; Wu, Shipo; Hou, Lihua; Wei, Wei; Zhou, Meng; Su, Zhiguo; Wu, Jie; Chen, Wei; Ma, Guanghui

2012-08-01

A novel thermal sensitive hydrogel was formulated with N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC) and α, β-glycerophosphate (α, β-GP). A serial of hydrogels containing different amount of GP and HTCC with diverse quarternize degree (QD, 41%, 59%, 79.5%, and 99%) were prepared and characterized by rheological method. The hydrogel was subsequently evaluated for intranasal vaccine delivery with adenovirus based Zaire Ebola virus glycoprotein antigen (Ad-GPZ). Results showed that moderate quarternized HTCC (60% and 79.5%) hydrogel/antigen formulations induced highest IgG, IgG1, and IgG2a antibody titers in serum, as well as mucosal IgA responses in lung wash, which may attributed to the prolonged antigen residence time due to the thermal-sensitivity of this hydrogel. Furthermore, CD8(+) splenocytes for IFN-γ positive cell assay and the release profile of Th1/Th2 type cytokines (IFN-γ, IL-2, IL-10, and IL-4) showed that hydrogel/Ad-GPZ generated an overwhelmingly enhanced Th1 biased cellular immune response. In addition, this hydrogel displayed low toxicity to nasal tissue and epithelial cells even by frequently intranasal dosing of hydrogel. All these results strongly supported this hydrogel as a safe and effective delivery system for nasal immunization. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Characteristics of 5-HT-containing chemoreceptor cells of the chicken aortic body

PubMed Central

Ito, Shigeo; Ohta, Toshio; Nakazato, Yoshikazu

1999-01-01

Voltage-dependent and oxygen-sensitive currents in 5-HT-containing epithelioid cells isolated from chicken thoracic aorta were examined using the whole-cell patch clamp technique. 5-HT immunoreactive cells were identified with Neutral Red. The release of 5-HT from chicken thoracic aorta in the presence of excess KCl and veratridine was also examined using HPLC. At a holding potential of −70 mV with CsCl pipette solution, depolarizing steps between −30 and +60 mV produced inward currents that were blocked by tetrodotoxin (0.2 μm). In the presence of tetrodotoxin and BaCl2 (5 mm), depolarizing steps evoked slow inward currents that were sensitive to CoCl2 (2 mm). Nifedipine (1 μm) decreased the currents to 79.4 ± 1.7%, and ω-conotoxin GVIA (1 μm) to 20.2 ± 3.8%. When KCl pipette solution was used, depolarizing potentials positive to −40 mV caused outward currents that were inhibited by tetraethylammonium chloride. The K+ currents evoked by depolarizing steps to +20 mV were reduced to 90.3 ± 0.8% by hypoxia in five out of seven cells. Two cells failed to respond to hypoxia. The K+ current response was partly decreased by Neutral Red (20 μm). Excess KCl (60 mm) and veratridine (30 μm) both caused the release of 5-HT from aortic strips. 5-HT outputs induced by both stimuli were partly inhibited by nifedipine (1 μm) and by ω-conotoxin GVIA (1 μm), and were abolished by these drugs in combination and by extracellular Ca2+ removal. These results suggest that epithelioid cells containing 5-HT act as chemoreceptor cells in the chicken aortic body, having voltage-dependent Na+, K+, and L- and N-type Ca2+ channels, and oxygen-sensitive K+ channels. PMID:9925877

Effect of emitter layer doping concentration on the performance of a silicon thin film heterojunction solar cell

NASA Astrophysics Data System (ADS)

Zhang, Lei; Shen, Hong-Lie; Yue, Zhi-Hao; Jiang, Feng; Wu, Tian-Ru; Pan, Yuan-Yuan

2013-01-01

A novel type of n/i/i/p heterojunction solar cell with a-Si:H(15 nm)/a-Si:H(10 nm)/ epitaxial c-Si(47 μm)/epitaxial c-Si(3 μm) structure is fabricated by using the layer transfer technique, and the emitter layer is deposited by hot wire chemical vapour deposition. The effect of the doping concentration of the emitter layer Sd (Sd=PH3/(PH3+SiH4+H2)) on the performance of the solar cell is studied by means of current density—voltage and external quantum efficiency. The results show that the conversion efficiency of the solar cell first increases to a maximum value and then decreases with Sd increasing from 0.1% to 0.4%. The best performance of the solar cell is obtained at Sd = 0.2% with an open circuit voltage of 534 mV, a short circuit current density of 23.35 mA/cm2, a fill factor of 63.3%, and a conversion efficiency of 7.9%.

Persistent Hydrogen Production by the Photo-Assisted Microbial Electrolysis Cell Using a p-Type Polyaniline Nanofiber Cathode.

PubMed

Jeon, Yongwon; Kim, Sunghyun

2016-12-08

A microbial electrolysis cell, though considered as a promising, environmentally friendly technology for hydrogen production, suffers from concomitant production of methane. The high hydrogen/methane ratio at the initial operation stage decreases with time. Here we report for the first time the photoassisted microbial electrolysis cell (MEC) for persistent hydrogen production using polyaniline nanofibers as a cathode. Under 0.8 V external bias and laboratory fluorescent light illumination in a single-chamber MEC, continuous hydrogen production from acetate at a rate of 1.78 mH2 3  m -3  d -1 with 79.2 % overall hydrogen recovery was achieved with negligible methane formation for six months. Energy efficiencies based on input electricity as well as input electricity plus substrate were 182 and 66.2 %, respectively. This was attributed to the p-type-semiconductor characteristics of polyaniline nanofibers in which photoexcited electrons are used to reduce protons at the surface and holes are reduced with electrons originating from acetate oxidation at the anode. This method can be extended to microbial wastewater treatment for hydrogen production. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rat coronaviruses infect rat alveolar type I epithelial cells and induce expression of CXC chemokines

PubMed Central

Miura, Tanya A.; Wang, Jieru; Holmes, Kathryn V.; Mason, Robert J.

2007-01-01

We analyzed the ability of two rat coronavirus (RCoV) strains, sialodacryoadenitis virus (SDAV) and Parker’s RCoV (RCoV-P), to infect rat alveolar type I cells and induce chemokine expression. Primary rat alveolar type II cells were transdifferentiated into the type I cell phenotype. Type I cells were productively infected with SDAV and RCoV-P, and both live virus and UV-inactivated virus induced mRNA and protein expression of three CXC chemokines: CINC-2, CINC-3, and LIX, which are neutrophil chemoattractants. Dual immunolabeling of type I cells for viral antigen and CXC chemokines showed that chemokines were expressed primarily by uninfected cells. Virus-induced chemokine expression was reduced by the IL-1 receptor antagonist, suggesting that IL-1 produced by infected cells induces uninfected cells to express chemokines. Primary cultures of alveolar epithelial cells are an important model for the early events in viral infection that lead to pulmonary inflammation. PMID:17804032

Interaction of phospholipid vesicles with cultured mammalial cells. I. Characteristics of uptake

PubMed Central

1975-01-01

The interaction of monolayer cultures of Chinese hamster V79 cells with artificially generated, unilamellar lipid vesicles (approximately 500 A diameter) was examined. Vesicles prepared from a variety of natural and synthetic radiolabeled phosphatidyl cholines (lecithins) were incubated with V79 cells bathed in a simple balanced salt solution. After incubation, the cells were analyzed for exogenous lipid incorporation. Large quantities (approximately 10(8) molecules/cell/h) of lecithin became cell associated without affecting cell viability. The effects of pH, charged lipids, and the influence of the vesicle lipid phase transition on the uptake process were examined. Glutaraldehyde fixation of cells before vesicle treatment, or incubation in the presence of metabolic inhibitors, failed to reduce the lecithin uptake by more than 25-50%, suggesting that the lipid uptake is largely energy independent. Cells in sparse culture took up about ten times more lipid than dense cultures. Prolonged incubation (greater than 15 h) of sparse cell cultures with lecithin vesicles resulted in significant cell death while no deleterious effect was found in dense cultures, or with 1:1 lecithin/cholesterol vesicles. When vesicle-treated cells were homogenized and fractionated, about 20-30% of the exogenous lipid was found in the plasma membrane fraction, with the remainder being distributed into intracellular fractions. Electron microscope radioautography further demonstrated that most of the internalized lipid was present in the cytoplasm, with little in the nucleus. These results are discussed in terms of possible modification of cell behavior by lipid vesicle treatment. PMID:240860

Direct methylation of FXR by Set7/9, a lysine methyltransferase, regulates the expression of FXR target genes

PubMed Central

Balasubramaniyan, Natarajan; Ananthanarayanan, Meena

2012-01-01

The farnesoid X receptor (FXR) is a ligand (bile acid)-dependent nuclear receptor that regulates target genes involved in every aspect of bile acid homeostasis. Upon binding of ligand, FXR recruits an array of coactivators and associated proteins, some of which have intrinsic enzymatic activity that modify histones or even components of the transcriptional complex. In this study, we show chromatin occupancy by the Set7/9 methyltransferase at the FXR response element (FXRE) and direct methylation of FXR in vivo and in vitro at lysine 206. siRNA depletion of Set7/9 in the Huh-7 liver cell line decreased endogenous mRNAs of the FXR target genes, the short heterodimer partner (SHP) and bile salt export pump (BSEP). Mutation of the methylation site at K206 of FXR to an arginine prevented methylation by Set7/9. A pan-methyllysine antibody recognized the wild-type FXR but not the K206R mutant form. An electromobility shift assay showed that methylation by Set7/9 enhanced binding of FXR/retinoic X receptor-α to the FXRE. Interaction between hinge domain of FXR (containing K206) and Set7/9 was confirmed by coimmunoprecipitation, GST pull down, and mammalian two-hybrid experiments. Set7/9 overexpression in Huh-7 cells significantly enhanced transactivation of the SHP and BSEP promoters in a ligand-dependent fashion by wild-type FXR but not the K206R mutant FXR. A Set7/9 mutant deficient in methyltransferase activity was also not effective in increasing transactivation of the BSEP promoter. These studies demonstrate that posttranslational methylation of FXR by Set7/9 contributes to the transcriptional activation of FXR-target genes. PMID:22345554

Evaluation of genotoxic and anti-mutagenic properties of cleistanthin A and cleistanthoside A tetraacetate.

PubMed

Himakoun, Lakana; Tuchinda, Patoomratana; Puchadapirom, Pranom; Tammasakchai, Ratigon; Leardkamolkarn, Vijittra

2011-01-01

Cleistanthin A (CleinA) and cleistanthoside A (CleisA) isolated from plant Phyllanthus taxodiifolius Beille have previously shown potent anticancer effects. To promote their medicinal benefits, CleisA was modified to cleistanthoside A tetraacetate (CleisTA) and evaluated for genotoxic and anti-mutagenic properties in comparison with CleinA. Both compounds showed no significant mutagenic activity to S. typhimulium bacteria and no cytotoxic effect to normal mammalian cells. The non genotoxic effect of CleinA was further confirmed by un-alteration of cytokinesis-block proliferation index (CBPI) and micronucleus (MN) frequency assays in Chinese hamster lung fibroblast (V79) cells, and of CleisTA was confirmed by un-changes of human peripheral blood lymphocytes (HPBL) chromosomal structure assay. Moreover, the metabolic form of CleinA efficiently demonstrated cytostasis effect to V79 cell and prevented mutagen induced Salmonella TA98 and TA100 reversion, whereas both metabolic and non-metabolic forms of CleisTA reduced HPBL mitotic index (%M.I) in a concentration-dependent relationship. The results support CleinA and CleisTA as the new lead compounds for anti-cancer drug development.

Intercellular ice propagation: experimental evidence for ice growth through membrane pores.

PubMed Central

Acker, J P; Elliott, J A; McGann, L E

2001-01-01

Propagation of intracellular ice between cells significantly increases the prevalence of intracellular ice in confluent monolayers and tissues. It has been proposed that gap junctions facilitate ice propagation between cells. This study develops an equation for capillary freezing-point depression to determine the effect of temperature on the equilibrium radius of an ice crystal sufficiently small to grow through gap junctions. Convection cryomicroscopy and video image analysis were used to examine the incidence and pattern of intracellular ice formation (IIF) in the confluent monolayers of cell lines that do (MDCK) and do not (V-79W) form gap junctions. The effect of gap junctions on intracellular ice propagation was strongly temperature-dependent. For cells with gap junctions, IIF occurred in a directed wave-like pattern in 100% of the cells below -3 degrees C. At temperatures above -3 degrees C, there was a marked drop in the incidence of IIF, with isolated individual cells initially freezing randomly throughout the sample. This random pattern of IIF was also observed in the V-79W monolayers and in MDCK monolayers treated to prevent gap junction formation. The significant change in the low temperature behavior of confluent MDCK monolayers at -3 degrees C is likely the result of the inhibition of gap junction-facilitated ice propagation, and supports the theory that gap junctions facilitate ice nucleation between cells. PMID:11509353

Transduction of hematopoietic stem cells to stimulate RNA interference against feline infectious peritonitis.

PubMed

Anis, Eman A; Dhar, Madhu; Legendre, Alfred M; Wilkes, Rebecca P

2017-06-01

Objectives The goals of the study were: (1) to develop and evaluate non-replicating lentivirus vectors coding for feline coronavirus (FCoV)-specific micro (mi)RNA as a potential antiviral therapy for feline infectious peritonitis (FIP); (2) to assess the feasibility of transducing hematopoietic stem cells (HSCs) with ex vivo introduction of the miRNA-expressing lentivirus vector; and (3) to assess the ability of the expressed miRNA to inhibit FCoV replication in HSCs in vitro. Methods HSCs were obtained from feline bone marrow and replicated in vitro. Three lentiviruses were constructed, each expressing a different anti-FCoV miRNA. HSCs were stably transduced with the miRNA-expressing lentivirus vector that produced the most effective viral inhibition in a feline cell line. The effectiveness of the transduction and the expression of anti-FCoV miRNA were tested by infecting the HSCs with two different strains of FCoV. The inhibition of coronavirus replication was determined by relative quantification of the inhibition of intracellular viral genomic RNA synthesis using real-time, reverse-transcription PCR. The assessment of virus replication inhibition was determined via titration of extracellular virus using the TCID 50 assay. Results Inhibition of FCoV was most significant in feline cells expressing miRNA-L2 that targeted the viral leader sequence, 48 h postinfection. miRNA-L2 expression in stably transduced HSCs resulted in 90% and 92% reductions in FIPV WSU 79-1146 genomic RNA synthesis and extracellular virus production, respectively, as well as 74% and 80% reduction in FECV WSU 79-1683 genomic RNA synthesis and extracellular virus production, respectively, as compared with an infected negative control sample producing non-targeting miRNA. Conclusions and relevance These preliminary results show that genetic modification of HSCs for constitutive production of anti-coronavirus miRNA will reduce FCoV replication.

Emulsions Made of Oils from Seeds of GM Flax Protect V79 Cells against Oxidative Stress

PubMed Central

Skorkowska-Telichowska, Katarzyna; Hasiewicz-Derkacz, Karolina; Gębarowski, Tomasz; Kulma, Anna; Kostyn, Kamil; Gębczak, Katarzyna; Szyjka, Anna; Wojtasik, Wioleta; Gąsiorowski, Kazimierz

2016-01-01

Polyunsaturated fatty acids, sterols, and hydrophilic phenolic compounds are components of flax oil that act as antioxidants. We investigated the impact of flax oil from transgenic flax in the form of emulsions on stressed Chinese hamster pulmonary fibroblasts. We found that the emulsions protect V79 cells against the H2O2 and the effect is dose dependent. They reduced the level of intracellular reactive oxygen species and protected genomic DNA against damage. The rate of cell proliferation increased upon treatment with the emulsions at a low concentration, while at a high concentration it decreased significantly, accompanied by increased frequency of apoptotic cell death. Expression analysis of selected genes revealed the upregulatory impact of the emulsions on the histones, acetylases, and deacetylases. Expression of apoptotic, proinflammatory, and anti-inflammatory genes was also altered. It is thus suggested that flax oil emulsions might be useful as a basis for biomedical products that actively protect cells against inflammation and degeneration. The beneficial effect on fibroblast resistance to oxidative damage was superior in the emulsion made of oil from transgenic plants which was correlated with the quantity of antioxidants and squalene. The emulsions from transgenic flax are promising candidates for skin protection against oxidative damage. PMID:26779302

Galectin-3: A novel substrate for c-Abl kinase.

PubMed

Balan, Vitaly; Nangia-Makker, Pratima; Jung, Young Suk; Wang, Yi; Raz, Avraham

2010-10-01

Galectin-3, a beta-galactoside-binding lectin, is found in cellular and extracellular location of the cell and has pleiotropic biological functions such as cell growth, cell adhesion and cell-cell interaction. It may exhibit anti- or pro-apoptotic activity depending on its localization and post-translational modifications. Two important post-translational modifications of galectin-3 have been reported: its cleavage and phosphorylation. Cleavage of galectin-3 was reported to be involved with angiogenic potential and apoptotic resistance. Phosphorylation of galectin-3 regulates its sugar-binding ability. In this report we have identified novel tyrosine phosphorylation sites in galectin-3 as well as the kinase responsible for its phosphorylation. Our results demonstrate that tyrosines at positions 79, 107 and 118 can be phosphorylated in vitro and in vivo by c-Abl kinase. Tyrosine 107 is the main target of c-Abl. Expression of galectin-3 Y107F mutant in galectin-3 null SK-Br-3 cells leads to morphological changes and increased motility compared to wild type galectin-3. Further investigation is needed to better understand the functional significance of the novel tyrosine phosphorylated sites of galectin-3. Copyright © 2010 Elsevier B.V. All rights reserved.

Glycosylation and Processing of Pro-B-type Natriuretic Peptide in Cardiomyocytes

PubMed Central

Peng, Jianhao; Jiang, Jingjing; Wang, Wei; Qi, Xiaofei; Sun, Xue-Long; Wu, Qingyu

2011-01-01

B-type natriuretic peptide (BNP) and its related peptides are biomarkers for the diagnosis of heart failure. Recent studies identified several O-glycosylation sites, including Thr-71, on human pro-BNP but the functional significance was unclear. In this study, we analyzed glycosylation and proteolytic processing of pro-BNP in cardiomyocytes. Human pro-BNP wild-type (WT) and mutants were expressed in HEK 293 cells and murine HL-1 cardiomyocytes. Pro-BNP and BNP were analyzed by immunoprecipitation and Western blotting. Glycosidases and glycosylation inhibitors were used to examine carbohydrates on pro-BNP. The effects of furin and corin expression on pro-BNP processing in cells also were examined. We found that in HEK 293 cells, recombinant pro-BNP contained significant amounts of O-glycans with terminal oligosialic acids. Mutation at Thr-71 reduced O-glycans on pro-BNP and increased pro-BNP processing. In HL-1 cardiomyocytes, residue Thr-71 contained little O-glycans, and pro-BNP WT and T71A mutant were processed similarly. In HEK 293 cells, pro-BNP was processed by furin. Mutations at Arg-73 and Arg-76, but not Lys-79, prevented pro-BNP processing. In HL-1 cardiomyocytes, which express furin and corin, single or double mutations at Arg-73, Arg-76 and Lys-79 did not prevent pro-BNP processing. Only when all these three residues were mutated, was pro-BNP processing completely blocked. Our data indicate that pro-BNP glycosylation in cardiomyocytes differed significantly from that in HEK 293 cells. In HEK 293 cells, furin cleaved pro-BNP at Arg-76 whereas in cardiomyocytes corin cleaved pro-BNP at multiple residues including Arg-73, Arg-76 and Lys-79. PMID:21763278

Influence of the transition region between p- and n-type polycrystalline silicon passivating contacts on the performance of interdigitated back contact silicon solar cells

NASA Astrophysics Data System (ADS)

Reichel, Christian; Müller, Ralph; Feldmann, Frank; Richter, Armin; Hermle, Martin; Glunz, Stefan W.

2017-11-01

Passivating contacts based on thin tunneling oxides (SiOx) and n- and p-type semi-crystalline or polycrystalline silicon (poly-Si) enable high passivation quality and low contact resistivity, but the integration of these p+/n emitter and n+/n back surface field junctions into interdigitated back contact silicon solar cells poses a challenge due to high recombination at the transition region from p-type to n-type poly-Si. Here, the transition region was created in different configurations—(a) p+ and n+ poly-Si regions are in direct contact with each other ("pn-junction"), using a local overcompensation (counterdoping) as a self-aligning process, (b) undoped (intrinsic) poly-Si remains between the p+ and n+ poly-Si regions ("pin-junction"), and (c) etched trenches separate the p+ and n+ poly-Si regions ("trench")—in order to investigate the recombination characteristics and the reverse breakdown behavior of these solar cells. Illumination- and injection-dependent quasi-steady state photoluminescence (suns-PL) and open-circuit voltage (suns-Voc) measurements revealed that non-ideal recombination in the space charge regions with high local ideality factors as well as recombination in shunted regions strongly limited the performance of solar cells without a trench. In contrast, solar cells with a trench allowed for open-circuit voltage (Voc) of 720 mV, fill factor of 79.6%, short-circuit current (Jsc) of 41.3 mA/cm2, and a conversion efficiencies (η) of 23.7%, showing that a lowly conducting and highly passivating intermediate layer between the p+ and n+ poly-Si regions is mandatory. Independent of the configuration, no hysteresis was observed upon multiple stresses in reverse direction, indicating a controlled and homogeneously distributed breakdown, but with different breakdown characteristics.

High local carcinogenic activity of 1,3-dimethyl-3-phenyl-1-nitrosourea and its inactivation by intravenous application in rats: comparison of in vivo findings with the in vitro direct and a combined in vivo/in vitro sister chromatid exchange assay in V79-E cells.

PubMed

Thust, R; Martin, J; Mendel, J; Schreiber, D

1987-02-01

1,3-Dimethyl-3-phenyl-1-nitrosourea (DMPNU) is a very potent local carcinogen in rats and induces a 100% frequency of forestomach carcinomas when applied i.g. in two different dosages (10 applications of 0.3 or 0.03 mmol/kg body wt, respectively, at 14-day intervals), but it is inactive upon i.v. administration (10 applications of 0.03 mmol/kg body wt at 14-day intervals). By means of the direct sister chromatid exchange (SCE) assay in V79-E cells in the presence of rat blood, serum or plasma, respectively, as well as by a 'host-mediated' SCE assay (in which the agent was given i.v. to rats, and blood taken from the animal was checked for the recovery of genotoxic activity in cell cultures), we tried to elucidate the unexpected lack of carcinogenic activity of i.v. DMPNU. The direct SCE assay revealed a drastic reduction of DMPNU genotoxicity by rat blood, serum or plasma, respectively, which is abolished by the esterase inhibitor diisopropylfluorophosphate. In the 'host-mediated' SCE assay a genotoxic activity of DMPNU was only recoverable after a very high i.v. dose and when the blood added to the cell cultures had been taken from the rat heart within 1 min after DMPNU administration in vivo. 1-Methyl-1-nitrosourea (MNU) and 1-methyl-3-phenyl-1-nitrosourea (MPNU) were used as positive controls in these experiments and also gave a lower response than theoretically expected, but the relative loss of activity with the latter compounds was much lower than with DMPNU. It is assumed that an esterase in rat blood effectively decomposes this trisubstituted nitrosourea. Problems of the novel 'host-mediated' SCE assay are discussed.

Recent insights into the implications of metabolism in plasmacytoid dendritic cell innate functions: Potential ways to control these functions.

PubMed

Saas, Philippe; Varin, Alexis; Perruche, Sylvain; Ceroi, Adam

2017-01-01

There are more and more data concerning the role of cellular metabolism in innate immune cells, such as macrophages or conventional dendritic cells. However, few data are available currently concerning plasmacytoid dendritic cells (PDC), another type of innate immune cells. These cells are the main type I interferon (IFN) producing cells, but they also secrete other pro-inflammatory cytokines (e.g., tumor necrosis factor or interleukin [IL]-6) or immunomodulatory factors (e.g., IL-10 or transforming growth factor-β). Through these functions, PDC participate in antimicrobial responses or maintenance of immune tolerance, and have been implicated in the pathophysiology of several autoimmune diseases, as well as in tumor immune escape mechanisms. Recent data support the idea that the glycolytic pathway (or glycolysis), as well as lipid metabolism (including both cholesterol and fatty acid metabolism) may impact some innate immune functions of PDC or may be involved in these functions after Toll-like receptor (TLR) 7/9 triggering. The kinetics of glycolysis after TLR7/9 triggering may differ between human and murine PDC. In mouse PDC, metabolism changes promoted by TLR7/9 activation may depend on an autocrine/paracrine loop, implicating type I IFN and its receptor IFNAR. This could explain a delayed glycolysis in mouse PDC. Moreover, PDC functions can be modulated by the metabolism of cholesterol and fatty acids. This may occur via the production of lipid ligands that activate nuclear receptors (e.g., liver X receptor [LXR]) in PDC or through limiting intracellular cholesterol pool size (by statin or LXR agonist treatment) in these cells. Finally, lipid-activated nuclear receptors (i.e., LXR or peroxisome proliferator activated receptor) may also directly interact with pro-inflammatory transcription factors, such as NF-κB. Here, we discuss how glycolysis and lipid metabolism may modulate PDC functions and how this may be harnessed in pathological situations where PDC play a detrimental role.

Recent insights into the implications of metabolism in plasmacytoid dendritic cell innate functions: Potential ways to control these functions

PubMed Central

Saas, Philippe; Varin, Alexis; Perruche, Sylvain; Ceroi, Adam

2017-01-01

There are more and more data concerning the role of cellular metabolism in innate immune cells, such as macrophages or conventional dendritic cells. However, few data are available currently concerning plasmacytoid dendritic cells (PDC), another type of innate immune cells. These cells are the main type I interferon (IFN) producing cells, but they also secrete other pro-inflammatory cytokines (e.g., tumor necrosis factor or interleukin [IL]-6) or immunomodulatory factors (e.g., IL-10 or transforming growth factor-β). Through these functions, PDC participate in antimicrobial responses or maintenance of immune tolerance, and have been implicated in the pathophysiology of several autoimmune diseases, as well as in tumor immune escape mechanisms. Recent data support the idea that the glycolytic pathway (or glycolysis), as well as lipid metabolism (including both cholesterol and fatty acid metabolism) may impact some innate immune functions of PDC or may be involved in these functions after Toll-like receptor (TLR) 7/9 triggering. The kinetics of glycolysis after TLR7/9 triggering may differ between human and murine PDC. In mouse PDC, metabolism changes promoted by TLR7/9 activation may depend on an autocrine/paracrine loop, implicating type I IFN and its receptor IFNAR. This could explain a delayed glycolysis in mouse PDC. Moreover, PDC functions can be modulated by the metabolism of cholesterol and fatty acids. This may occur via the production of lipid ligands that activate nuclear receptors (e.g., liver X receptor [LXR]) in PDC or through limiting intracellular cholesterol pool size (by statin or LXR agonist treatment) in these cells. Finally, lipid-activated nuclear receptors (i.e., LXR or peroxisome proliferator activated receptor) may also directly interact with pro-inflammatory transcription factors, such as NF-κB. Here, we discuss how glycolysis and lipid metabolism may modulate PDC functions and how this may be harnessed in pathological situations where PDC play a detrimental role. PMID:28580131

CaV 3.1 and CaV 3.3 account for T-type Ca2+ current in GH3 cells.

PubMed

Mudado, M A; Rodrigues, A L; Prado, V F; Beirão, P S L; Cruz, J S

2004-06-01

T-type Ca2+ channels are important for cell signaling by a variety of cells. We report here the electrophysiological and molecular characteristics of the whole-cell Ca2+ current in GH3 clonal pituitary cells. The current inactivation at 0 mV was described by a single exponential function with a time constant of 18.32 +/- 1.87 ms (N = 16). The I-V relationship measured with Ca2+ as a charge carrier was shifted to the left when we applied a conditioning pre-pulse of up to -120 mV, indicating that a low voltage-activated current may be present in GH3 cells. Transient currents were first activated at -50 mV and peaked around -20 mV. The half-maximal voltage activation and the slope factors for the two conditions are -35.02 +/- 2.4 and 6.7 +/- 0.3 mV (pre-pulse of -120 mV, N = 15), and -27.0 +/- 0.97 and 7.5 +/- 0.7 mV (pre-pulse of -40 mV, N = 9). The 8-mV shift in the activation mid-point was statistically significant (P < 0.05). The tail currents decayed bi-exponentially suggesting two different T-type Ca2+ channel populations. RT-PCR revealed the presence of alpha1G (CaV3.1) and alpha1I (CaV3.3) T-type Ca2+ channel mRNA transcripts.

ck2-dependent phosphorylation of progesterone receptors (PR) on Ser81 regulates PR-B isoform-specific target gene expression in breast cancer cells.

PubMed

Hagan, Christy R; Regan, Tarah M; Dressing, Gwen E; Lange, Carol A

2011-06-01

Progesterone receptors (PR) are critical mediators of mammary gland development and contribute to breast cancer progression. Progestin-induced rapid activation of cytoplasmic protein kinases leads to selective regulation of growth-promoting genes by phospho-PR species. Herein, we show that phosphorylation of PR Ser81 is ck2 dependent and progestin regulated in intact cells but also occurs in the absence of PR ligands when cells enter the G(1)/S phase of the cell cycle. T47D breast cancer cells stably expressing a PR-B mutant receptor that cannot be phosphorylated at Ser79/81 (S79/81A) formed fewer soft agar colonies. Regulation of selected genes by PR-B, but not PR-A, also required Ser79/81 phosphorylation for basal and/or progestin-regulated (BIRC3, HSD11β2, and HbEGF) expression. Additionally, wild-type (wt) PR-B, but not S79/81A mutant PR, was robustly recruited to a progesterone response element (PRE)-containing transcriptional enhancer region of BIRC3; abundant ck2 also associated with this region in cells expressing wt but not S79/81A PR. We conclude that phospho-Ser81 PR provides a platform for ck2 recruitment and regulation of selected PR-B target genes. Understanding how ligand-independent PRs function in the context of high levels of kinase activities characteristic of breast cancer is critical to understanding the basis of tumor-specific changes in gene expression and will speed the development of highly selective treatments.

ck2-Dependent Phosphorylation of Progesterone Receptors (PR) on Ser81 Regulates PR-B Isoform-Specific Target Gene Expression in Breast Cancer Cells ▿

PubMed Central

Hagan, Christy R.; Regan, Tarah M.; Dressing, Gwen E.; Lange, Carol A.

2011-01-01

Progesterone receptors (PR) are critical mediators of mammary gland development and contribute to breast cancer progression. Progestin-induced rapid activation of cytoplasmic protein kinases leads to selective regulation of growth-promoting genes by phospho-PR species. Herein, we show that phosphorylation of PR Ser81 is ck2 dependent and progestin regulated in intact cells but also occurs in the absence of PR ligands when cells enter the G1/S phase of the cell cycle. T47D breast cancer cells stably expressing a PR-B mutant receptor that cannot be phosphorylated at Ser79/81 (S79/81A) formed fewer soft agar colonies. Regulation of selected genes by PR-B, but not PR-A, also required Ser79/81 phosphorylation for basal and/or progestin-regulated (BIRC3, HSD11β2, and HbEGF) expression. Additionally, wild-type (wt) PR-B, but not S79/81A mutant PR, was robustly recruited to a progesterone response element (PRE)-containing transcriptional enhancer region of BIRC3; abundant ck2 also associated with this region in cells expressing wt but not S79/81A PR. We conclude that phospho-Ser81 PR provides a platform for ck2 recruitment and regulation of selected PR-B target genes. Understanding how ligand-independent PRs function in the context of high levels of kinase activities characteristic of breast cancer is critical to understanding the basis of tumor-specific changes in gene expression and will speed the development of highly selective treatments. PMID:21518957

Exfoliated cells of the oral mucosa for HPV typing by SPF10 in head and neck cancer.

PubMed

Morbini, Patrizia; Dal Bello, Barbara; Alberizzi, Paola; Mannarini, Laura; Mevio, Niccolò; Bertino, Giulia; Benazzo, Marco

2012-12-01

HPV infection in the superficial cells of the oral mucosa could reflect the presence of HPV in head and neck cancer cells. Due mostly to the use of heterogeneous analytical methods, discordant data exist in the literature regarding the agreement between the presence of HPV in non-neoplastic oral mucosa and in tumour tissue from the same patient. The presence of HPV DNA and viral types were compared in paired cytological and biopsy samples from 56 patients with head and neck neoplastic and preneoplastic lesions using the highly sensitive SPF10 LiPA Extra assay, which has been validated recently for formalin-fixed paraffin-embedded tissue using paired cervical cytology and biopsy samples. Kappa statistics were used to measure the inter-rater agreement. The overall agreement with respect to HPV infection was 96.43% (kappa=0.8367). For 76.79% of subjects (kappa=0.6937), the same number of HPV types was detected in cytological and biopsy specimens. The overall positive typing agreement was 90.90%, comprising 130 out of 143 individual HPV type analyses. The agreement shown was good for HPV 18, 44, 45, 54 and 66 (kappa=0.6585-0. 7321), excellent for HPV 6, 16, 40, and 54 (kappa=0.8108-0.8679), and absolute for HPV 11, 31, 33, 35, 39, 51, 52, 53, 59, 74, and 69-71 (kappa=1.0000). The high sensitivity of the SPF10 LiPA and its excellent performance both for recognising HPV infection and for identifying the viral types present in tumour tissue and in oral exfoliated cells make it a useful method for the assessment of HPV infection in patients with head and neck cancer. The excellent agreement for HPV infection and genotyping in paired samples suggests that oral exfoliated cells can be used for HPV detection in the head and neck region. Copyright © 2012 Elsevier B.V. All rights reserved.

Direct Exposure of Monolayers of Mammalian Cells to Airborne Pollutants in a Unique Culture System.

DTIC Science & Technology

1981-02-01

of growth medium through the filter from the side opposite the cells so that they are nourished and kept moist. Growth medium perfusing through the...planting dispersed cells (Line V79, Chinese hamster lung fibroblasts) on the membrane filters and exposing to the test gas. The toxic effect was... Medium which perfuses through the filters is drawn off through the tubes at the rear wall of the chamber. The test gas enters at the left end of the

SARS-CoV replicates in primary human alveolar type II cell cultures but not in type I-like cells

PubMed Central

Mossel, Eric C.; Wang, Jieru; Jeffers, Scott; Edeen, Karen E.; Wang, Shuanglin; Cosgrove, Gregory P.; Funk, C. Joel; Manzer, Rizwan; Miura, Tanya A.; Pearson, Leonard D.; Holmes, Kathryn V.; Mason, Robert J.

2008-01-01

Severe acute respiratory syndrome (SARS) is a disease characterized by diffuse alveolar damage. We isolated alveolar type II cells and maintained them in a highly differentiated state. Type II cell cultures supported SARS-CoV replication as evidenced by RT-PCR detection of viral subgenomic RNA and an increase in virus titer. Virus titers were maximal by 24 hours and peaked at approximately 105 pfu/mL. Two cell types within the cultures were infected. One cell type was type II cells, which were positive for SP-A, SP-C, cytokeratin, a type II cell-specific monoclonal antibody, and Ep-CAM. The other cell type was composed of spindle-shaped cells that were positive for vimentin and collagen III and likely fibroblasts. Viral replication was not detected in type I-like cells or macrophages. Hence, differentiated adult human alveolar type II cells were infectible but alveolar type I-like cells and alveolar macrophages did not support productive infection. PMID:18022664

Testing of the cytotoxic effects of sulfate pulp mill waste waters.

PubMed

Cernáková, M; Golis, E

1994-01-01

The effect of 22 technological waste water samples and of some standards was tested on bacteria, fungi, chlorococcal algae, flagellata, plant cells, cells of Tubifex tubifex, hamster cells V79 and the fish Lebistes reticulatus. Of these 22 samples, some inhibition of cell life processes was displayed by the black liquor formed in the production of paper pulp and viscose pulp, by the waste solution produced during the preparation of bleaching agents for paper pulp and viscose pulp, and by the residual liquor after hypochlorite treatment of paper pulp.

Calculation of Heavy Ion Inactivation and Mutation Rates in Radial Dose Model of Track Structure

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Wilson, John W.; Shavers, Mark R.; Katz, Robert

1997-01-01

In the track structure model, the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated by using the dose response of the system to gamma rays and the radial dose of the ions and may be equal to unity at small impact parameters. We apply the track structure model to recent data with heavy ion beams irradiating biological samples of E. Coli, B. Subtilis spores, and Chinese hamster (V79) cells. Heavy ions have observed cross sections for inactivation that approach and sometimes exceed the geometric size of the cell nucleus. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT (hypoxanthine guanine phosphoribosyl transferase) mutations in V79 cells, and good agreement is found. Calculations show the high probability for mutation by relativistic ions due to the radial extension of ions track from delta rays. The effects of inactivation on mutation rates make it very unlikely that a single parameter such as LET (linear energy transfer) can be used to specify radiation quality for heavy ion bombardment.

EZH2 and CD79B mutational status over time in B-cell non-Hodgkin lymphomas detected by high-throughput sequencing using minimal samples

PubMed Central

Saieg, Mauro Ajaj; Geddie, William R; Boerner, Scott L; Bailey, Denis; Crump, Michael; da Cunha Santos, Gilda

2013-01-01

BACKGROUND: Numerous genomic abnormalities in B-cell non-Hodgkin lymphomas (NHLs) have been revealed by novel high-throughput technologies, including recurrent mutations in EZH2 (enhancer of zeste homolog 2) and CD79B (B cell antigen receptor complex-associated protein beta chain) genes. This study sought to determine the evolution of the mutational status of EZH2 and CD79B over time in different samples from the same patient in a cohort of B-cell NHLs, through use of a customized multiplex mutation assay. METHODS: DNA that was extracted from cytological material stored on FTA cards as well as from additional specimens, including archived frozen and formalin-fixed histological specimens, archived stained smears, and cytospin preparations, were submitted to a multiplex mutation assay specifically designed for the detection of point mutations involving EZH2 and CD79B, using MassARRAY spectrometry followed by Sanger sequencing. RESULTS: All 121 samples from 80 B-cell NHL cases were successfully analyzed. Mutations in EZH2 (Y646) and CD79B (Y196) were detected in 13.2% and 8% of the samples, respectively, almost exclusively in follicular lymphomas and diffuse large B-cell lymphomas. In one-third of the positive cases, a wild type was detected in a different sample from the same patient during follow-up. CONCLUSIONS: Testing multiple minimal tissue samples using a high-throughput multiplex platform exponentially increases tissue availability for molecular analysis and might facilitate future studies of tumor progression and the related molecular events. Mutational status of EZH2 and CD79B may vary in B-cell NHL samples over time and support the concept that individualized therapy should be based on molecular findings at the time of treatment, rather than on results obtained from previous specimens. Cancer (Cancer Cytopathol) 2013;121:377–386. © 2013 American Cancer Society. PMID:23361872

Seroreactivity against Merkel cell polyomavirus and other polyomaviruses in chronic lymphocytic leukaemia, the MCC-Spain study.

PubMed

Robles, Claudia; Casabonne, Delphine; Benavente, Yolanda; Costas, Laura; Gonzalez-Barca, Eva; Aymerich, Marta; Campo, Elias; Tardon, Adonina; Jiménez-Moleón, José J; Castaño-Vinyals, Gemma; Dierssen-Sotos, Trinidad; Michel, Angelika; Kranz, Lena; Aragonés, Nuria; Pollan, Marina; Kogevinas, Manolis; Pawlita, Michael; de Sanjose, Silvia

2015-08-01

Merkel cell polyomavirus (MCPyV) has been suspected to cause chronic lymphocytic leukaemia (CLL) but previous data are inconsistent. We measured seroreactivities of nine polyomaviruses (MCPyV, BKPyV, JCPyV, LPyV, KIPyV, WUPyV, HPyV-6, HPyV-7 and TSPyV) in 359 CLL cases and 370 controls using bead-based multiplex serology technology. We additionally tested two herpesviruses (HSV-1 and CMV). Associations between disease and viral seroreactivities were assessed using logistic regression. All human viruses showed high seroprevalences (69-99%) against structural proteins in controls but significantly lower viral seroprevalences in cases (58-94%; OR range = 0.21-0.70, P value < 0.05), except for MCPyV (OR = 0.79, 95% CI = 0.54-1.16). Lower seroreactivity levels were observed among CLL subjects, with significant differences already observed at early stages of disease, unrelated to treatment status. Seroreactivities against polyomavirus related oncoproteins were almost null. Our data suggest no association for MCPyV polyomavirus with CLL development and an unlikely association for other polyomaviruses tested.

NIFLUMIC ACID BLOCKS NATIVE AND RECOMBINANT T-TYPE CHANNELS

PubMed Central

Balderas, E; Arteaga-Tlecuitl, R; Rivera, M; Gomora, JC; Darszon, A

2012-01-01

Voltage-dependent calcium channels are widely distributed in animal cells, including spermatozoa. Calcium is fundamental in many sperm functions such as: motility, capacitation and the acrosome reaction, all essential for fertilization. Pharmacological evidence has suggested T-type calcium channels participate in the acrosome reaction. Niflumic acid (NA), a non-steroidal anti-inflammatory drug commonly used as chloride channel blocker, blocks T-currents in mouse spermatogenic cells and Cl− channels in testicular sperm. Here we examine the mechanism of NA blockade and explore if it can be used to separate the contribution of different CaV3 members previously detected in these cells. Electrophysiological patch-clamp recordings were performed in isolated mouse spermatogenic cells and in HEK cells heterologously expressing CaV3 channels. NA blocks mouse spermatogenic cell T-type currents with an IC50 of 73.5 µM, without major voltage-dependent effects. The NA blockade is more potent in the open and in the inactivated state than in the closed state of the T-type channels. Interestingly, we found that heterologously expressed CaV3.1 and CaV3.3 channels were more sensitive to NA than CaV3.2 channels, and this drug substantially slowed the recovery from inactivation of the three isoforms. Molecular docking modeling of drug-channel binding predicts that NA binds preferentially to the extracellular face of CaV3.1 channels. The biophysical characteristics of mouse spermatogenic cell T-type currents more closely resemble those from heterologously expressed CaV3.1 channels, including their sensitivity to NA. As CaV3.1 null mice maintain their spermatogenic cell T-currents, it is likely that a novel CaV3.2 isoform is responsible for them. PMID:21898399

Analysis of the GCK gene in 79 MODY type 2 patients: A multicenter Turkish study, mutation profile and description of twenty novel mutations.

PubMed

Aykut, Ayça; Karaca, Emin; Onay, Hüseyin; Gökşen, Damla; Çetinkalp, Şevki; Eren, Erdal; Ersoy, Betül; Çakır, Esra Papatya; Büyükinan, Muammer; Kara, Cengiz; Anık, Ahmet; Kırel, Birgül; Özen, Samim; Atik, Tahir; Darcan, Şükran; Özkınay, Ferda

2018-01-30

Maturity onset diabetes is a genetic form of diabetes mellitus characterized by an early age at onset and several etiologic genes for this form of diabetes have been identified in many patients. Maturity onset diabetes type 2 [MODY2 (#125851)] caused by mutations in the glucokinase gene (GCK). Although its prevalence is not clear, it is estimated that 1%-2% of patients with diabetes have the monogenic form. The aim of this study was to evaluate the molecular spectrum of GCK gene mutations in 177 Turkish MODY type 2 patients. Mutations in the GCK gene were identified in 79 out of 177. All mutant alleles were identified, including 45 different GCK mutations, 20 of which were novel. Copyright © 2017. Published by Elsevier B.V.

Sustained induction of cytochrome P4501A1 in human hepatoma cells by co-exposure to benzo[a]pyrene and 7H-dibenzo[c,g]carbazole underlies the synergistic effects on DNA adduct formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gábelová, Alena, E-mail: alena.gabelova@savba.sk; Poláková, Veronika; Prochazka, Gabriela

To gain a deeper insight into the potential interactions between individual aromatic hydrocarbons in a mixture, several benzo[a]pyrene (B[a]P) and 7H-dibenzo[c,g]carbazole (DBC) binary mixtures were studied. The biological activity of the binary mixtures was investigated in the HepG2 and WB-F344 liver cell lines and the Chinese hamster V79 cell line that stably expresses the human cytochrome P4501A1 (hCYP1A1). In the V79 cells, binary mixtures, in contrast to individual carcinogens, caused a significant decrease in the levels of micronuclei, DNA adducts and gene mutations, but not in cell survival. Similarly, a lower frequency of micronuclei and levels of DNA adducts weremore » found in rat liver WB-F344 cells treated with a binary mixture, regardless of the exposure time. The observed antagonism between B[a]P and DBC may be due to an inhibition of Cyp1a1 expression because cells exposed to B[a]P:DBC showed a decrease in Cyp1a1 mRNA levels. In human liver HepG2 cells exposed to binary mixtures for 2 h, a reduction in micronuclei frequency was also found. However, after a 24 h treatment, synergism between B[a]P and DBC was determined based on DNA adduct formation. Accordingly, the up-regulation of CYP1A1 expression was detected in HepG2 cells exposed to B[a]P:DBC. Our results show significant differences in the response of human and rat cells to B[a]P:DBC mixtures and stress the need to use multiple experimental systems when evaluating the potential risk of environmental pollutants. Our data also indicate that an increased expression of CYP1A1 results in a synergistic effect of B[a]P and DBC in human cells. As humans are exposed to a plethora of noxious chemicals, our results have important implications for human carcinogenesis. - Highlights: • B[a]P:DBC mixtures were less genotoxic in V79MZh1A1 cells than B[a]P and DBC alone. • An antagonism between B[a]P and DBC was determined in rat liver WB-F344 cells. • The inhibition of CYP1a1 expression by B[a]P:DBC mixture underlies this antagonism. • A synergism between B[a]P and DBC was detected in human liver HepG2 cells. • The up-regulation of CYP1A1 expression was found in B[a]P:DBC-exposed HepG2 cells.« less

Cassava Plants with a Depleted Cyanogenic Glucoside Content in Leaves and Tubers. Distribution of Cyanogenic Glucosides, Their Site of Synthesis and Transport, and Blockage of the Biosynthesis by RNA Interference Technology1

PubMed Central

Jørgensen, Kirsten; Bak, Søren; Busk, Peter Kamp; Sørensen, Charlotte; Olsen, Carl Erik; Puonti-Kaerlas, Johanna; Møller, Birger Lindberg

2005-01-01

Transgenic cassava (Manihot esculenta Crantz, cv MCol22) plants with a 92% reduction in cyanogenic glucoside content in tubers and acyanogenic (<1% of wild type) leaves were obtained by RNA interference to block expression of CYP79D1 and CYP79D2, the two paralogous genes encoding the first committed enzymes in linamarin and lotaustralin synthesis. About 180 independent lines with acyanogenic (<1% of wild type) leaves were obtained. Only a few of these were depleted with respect to cyanogenic glucoside content in tubers. In agreement with this observation, girdling experiments demonstrated that cyanogenic glucosides are synthesized in the shoot apex and transported to the root, resulting in a negative concentration gradient basipetal in the plant with the concentration of cyanogenic glucosides being highest in the shoot apex and the petiole of the first unfolded leaf. Supply of nitrogen increased the cyanogenic glucoside concentration in the shoot apex. In situ polymerase chain reaction studies demonstrated that CYP79D1 and CYP79D2 were preferentially expressed in leaf mesophyll cells positioned adjacent to the epidermis. In young petioles, preferential expression was observed in the epidermis, in the two first cortex cell layers, and in the endodermis together with pericycle cells and specific parenchymatic cells around the laticifers. These data demonstrate that it is possible to drastically reduce the linamarin and lotaustralin content in cassava tubers by blockage of cyanogenic glucoside synthesis in leaves and petioles. The reduced flux to the roots of reduced nitrogen in the form of cyanogenic glucosides did not prevent tuber formation. PMID:16126856

A rare mutation in AgRP, +79G>A, affects promoter activity.

PubMed

Sözen, M A; de Jonge, L H M; Greenway, F; Ravussin, E; Smith, S R; Argyropoulos, G

2007-06-01

The agouti-related protein is a powerful orexigenic peptide. A rare mutation, +79G>A, was identified in its minimal promoter in two white carriers. Comparison of the 45-year-old male proband, who was also a carrier of the common Ala67Thr polymorphism, with an age- and weight-matching wild-type population showed marginal differences for resting metabolic rate (RMR) and body mass index. The second carrier however was an obese 57-year-old female with reduced RMR. Functional analysis in hypothalamus- and periphery-derived cell lines showed reduced promoter activity for the +79A allele in the adrenocortical cells only, suggesting that it could affect the peripheral expression levels of AgRP. The +79G>A mutation could predispose to body weight gain (as suggested by the phenotype of the second carrier), but it could only affect the proband at an older age as he may be protected by the Ala67Thr polymorphism that is associated with resistance to late-onset fatness.

Culture Medium Supplements Derived from Human Platelet and Plasma: Cell Commitment and Proliferation Support

PubMed Central

Muraglia, Anita; Nguyen, Van Thi; Nardini, Marta; Mogni, Massimo; Coviello, Domenico; Dozin, Beatrice; Strada, Paolo; Baldelli, Ilaria; Formica, Matteo; Cancedda, Ranieri; Mastrogiacomo, Maddalena

2017-01-01

Present cell culture medium supplements, in most cases based on animal sera, are not fully satisfactory especially for the in vitro expansion of cells intended for human cell therapy. This paper refers to (i) an heparin-free human platelet lysate (PL) devoid of serum or plasma components (v-PL) and (ii) an heparin-free human serum derived from plasma devoid of PL components (Pl-s) and to their use as single components or in combination in primary or cell line cultures. Human mesenchymal stem cells (MSC) primary cultures were obtained from adipose tissue, bone marrow, and umbilical cord. Human chondrocytes were obtained from articular cartilage biopsies. In general, MSC expanded in the presence of Pl-s alone showed a low or no proliferation in comparison to cells grown with the combination of Pl-s and v-PL. Confluent, growth-arrested cells, either human MSC or human articular chondrocytes, treated with v-PL resumed proliferation, whereas control cultures, not supplemented with v-PL, remained quiescent and did not proliferate. Interestingly, signal transduction pathways distinctive of proliferation were activated also in cells treated with v-PL in the absence of serum, when cell proliferation did not occur, indicating that v-PL could induce the cell re-entry in the cell cycle (cell commitment), but the presence of serum proteins was an absolute requirement for cell proliferation to happen. Indeed, Pl-s alone supported cell growth in constitutively activated cell lines (U-937, HeLa, HaCaT, and V-79) regardless of the co-presence of v-PL. Plasma- and plasma-derived serum were equally able to sustain cell proliferation although, for cells cultured in adhesion, the Pl-s was more efficient than the plasma from which it was derived. In conclusion, the cells expanded in the presence of the new additives maintained their differentiation potential and did not show alterations in their karyotype. PMID:29209609

Evaluation of the cytotoxic and antimutagenic effects of biflorin, an antitumor 1,4 o-naphthoquinone isolated from Capraria biflora L.

PubMed

Vasconcellos, Marne C; Moura, Dinara J; Rosa, Renato M; Machado, Miriana S; Guecheva, Temenouga N; Villela, Izabel; Immich, Bruna F; Montenegro, Raquel C; Fonseca, Aluísio M; Lemos, Telma L G; Moraes, Maria Elisabete A; Saffi, Jenifer; Costa-Lotufo, Letícia V; Moraes, Manoel O; Henriques, João A P

2010-10-01

Biflorin is a natural quinone isolated from Capraria biflora L. Previous studies demonstrated that biflorin inhibits in vitro and in vivo tumor cell growth and presents potent antioxidant activity. In this paper, we report concentration-dependent cytotoxic, genotoxic, antimutagenic, and protective effects of biflorin on Salmonella tiphymurium, yeast Saccharomyces cerevisiae, and V79 mammalian cells, using different approaches. In the Salmonella/microsome assay, biflorin was not mutagenic to TA97a TA98, TA100, and TA102 strains. However, biflorin was able to induce cytotoxicity in haploid S. cerevisiae cells in stationary and exponential phase growth. In diploid yeast cells, biflorin did not induce significant mutagenic and recombinogenic effects at the employed concentration range. In addition, the pre-treatment with biflorin prevented the mutagenic and recombinogenic events induced by hydrogen peroxide (H(2)O(2)) in S. cerevisiae. In V79 mammalian cells, biflorin was cytotoxic at higher concentrations. Moreover, at low concentrations biflorin pre-treatment protected against H(2)O(2)-induced oxidative damage by reducing lipid peroxidation and DNA damage as evaluated by normal and modified comet assay using DNA glycosylases. Our results suggest that biflorin cellular effects are concentration dependent. At lower concentrations, biflorin has significant antioxidant and protective effects against the cytotoxicity, genotoxicity, mutagenicity, and intracellular lipid peroxidation induced by H(2)O(2) in yeast and mammalian cells, which can be attributed to its hydroxyl radical-scavenging property. However, at higher concentrations, biflorin is cytotoxic and genotoxic.

Efficient Transformation of Primary Human Mesenchymal Stromal Cells by Adenovirus Early Region 1 Oncogenes.

PubMed

Speiseder, Thomas; Hofmann-Sieber, Helga; Rodríguez, Estefanía; Schellenberg, Anna; Akyüz, Nuray; Dierlamm, Judith; Spruss, Thilo; Lange, Claudia; Dobner, Thomas

2017-01-01

Previous observations that human amniotic fluid cells (AFC) can be transformed by human adenovirus type 5 (HAdV-5) E1A/E1B oncogenes prompted us to identify the target cells in the AFC population that are susceptible to transformation. Our results demonstrate that one cell type corresponding to mesenchymal stem/stroma cells (hMSCs) can be reproducibly transformed by HAdV-5 E1A/E1B oncogenes as efficiently as primary rodent cultures. HAdV-5 E1-transformed hMSCs exhibit all properties commonly associated with a high grade of oncogenic transformation, including enhanced cell proliferation, anchorage-independent growth, increased growth rate, and high telomerase activity as well as numerical and structural chromosomal aberrations. These data confirm previous work showing that HAdV preferentially transforms cells of mesenchymal origin in rodents. More importantly, they demonstrate for the first time that human cells with stem cell characteristics can be completely transformed by HAdV oncogenes in tissue culture with high efficiency. Our findings strongly support the hypothesis that undifferentiated progenitor cells or cells with stem cell-like properties are highly susceptible targets for HAdV-mediated cell transformation and suggest that virus-associated tumors in humans may originate, at least in part, from infections of these cell types. We expect that primary hMSCs will replace the primary rodent cultures in HAdV viral transformation studies and are confident that these investigations will continue to uncover general principles of viral oncogenesis that can be extended to human DNA tumor viruses as well. It is generally believed that transformation of primary human cells with HAdV-5 E1 oncogenes is very inefficient. However, a few cell lines have been successfully transformed with HAdV-5 E1A and E1B, indicating that there is a certain cell type which is susceptible to HAdV-mediated transformation. Interestingly, all those cell lines have been derived from human embryonic tissue, albeit the exact cell type is not known yet. We show for the first time the successful transformation of primary human mesenchymal stromal cells (hMSCs) by HAdV-5 E1A and E1B. Further, we show upon HAdV-5 E1A and E1B expression that these primary progenitor cells exhibit features of tumor cells and can no longer be differentiated into the adipogenic, chondrogenic, or osteogenic lineage. Hence, primary hMSCs represent a robust and novel model system to elucidate the underlying molecular mechanisms of adenovirus-mediated transformation of multipotent human progenitor cells. Copyright © 2016 American Society for Microbiology.

The application of the micronucleus test in Chinese hamster V79 cells to detect drug-induced photogenotoxicity.

PubMed

Kersten, B; Zhang, J; Brendler-Schwaab, S Y; Kasper, P; Müller, L

1999-09-15

Recent reports on the photochemical carcinogenicity and photochemical genotoxicity of fluoroquinolone antibacterials led to an increasing awareness for the need of a standard approach to test for photochemical genotoxicity. In this study the micronucleus test using V79 cells was adapted to photogenotoxicity testing. Results of using different UVA/UVB relationships enabled us to identify a suitable irradiation regimen for the activation of different kinds of photosensitizers. Using this regimen, 8-methoxypsoralen and the fluoroquinolones lomefloxacin, grepafloxacin and Bay Y 3118 were identified to cause micronuclei and toxicity upon photochemical activation. Among the phenothiazines tested, chlorpromazine and 2-chlorophenothiazine, were positive for both endpoints, whereas triflupromazine was only slightly photoclastogenic in the presence of strong phototoxicity. Among the other potential human photosensitizers tested (oxytetracycline, doxycycline, metronidazole, emodin, hypericin, griseofulvin), only hypericin was slightly photogenotoxic. Photochemical toxicity in the absence of photochemical genotoxicity was noted for doxycycline and emodin. With the assay system described, it is possible to determine photochemical toxicity and photochemical genotoxicity concomitantly with sufficient reliability.

Angiogenesis Research to Improve Therapies for Vascular Leak Syndromes, Intra-abdominal Adhesions, and Arterial Injuries

DTIC Science & Technology

2008-04-01

small-cell lung cancer; TFP1, transferrin pseudogene 1; TGFβ, transforming growth factor-β; TNF, tumour- necrosis factor; uPA, urokinase-type plasminogen...Cell 79, 315–328 (1994). 23. Frater-Schroder, M., Risau, W., Hallmann, R., Gautschi, P. & Bohlen, P. Tumor necrosis factor type α, a potent inhibitor...relatively thin (skin) or avascular (cartilage) tissues, where post- implantation vascularization from the host is sufficient. To overcome the problem

Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

DOE PAGES

David, Tanya M. S.; Zhang, Cheng; Sun, Sam-Shajing

2014-01-01

Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene) or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO) level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO) level of −3.33 eV based on optical energy gap. The polymer wasmore » synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.« less

Enhanced conversion efficiency in wide-bandgap GaNP solar cells

DOE PAGES

Sukrittanon, Supanee; Liu, Ren; Ro, Yun Goo; ...

2015-10-12

In this study, we demonstrate –2.05 eV dilute nitride GaNP solar cells on GaP substrates for potential use as the top junction in dual-junction integrated cells on Si. By adding a small amount of N into indirect-bandgap GaP, GaNP has several extremely important attributes: a direct-bandgap that is also tunable, and easily attained lattice-match with Si. Our best GaNP solar cell ([N] –1.8%, E g –2.05 eV) achieves an efficiency of 7.9%, even in the absence of a window layer. This GaNP solar cell's efficiency is 3× higher than the most efficient GaP solar cell to date and higher thanmore » other solar cells with similar direct bandgap (InGaP, GaAsP). Through a systematic study of the structural, electrical, and optical properties of the device, efficient broadband optical absorption and enhanced solar cell performance are demonstrated.« less

Cell surface retention sequence binding protein-1 interacts with the v-sis gene product and platelet-derived growth factor beta-type receptor in simian sarcoma virus-transformed cells.

PubMed

Boensch, C; Huang, S S; Connolly, D T; Huang, J S

1999-04-09

The cell surface retention sequence (CRS) binding protein-1 (CRSBP-1) is a newly identified membrane glycoprotein which is hypothesized to be responsible for cell surface retention of the oncogene v-sis and c-sis gene products and other secretory proteins containing CRSs. In simian sarcoma virus-transformed NIH 3T3 cells (SSV-NIH 3T3 cells), a fraction of CRSBP-1 was demonstrated at the cell surface and underwent internalization/recycling as revealed by cell surface 125I labeling and its resistance/sensitivity to trypsin digestion. However, the majority of CRSBP-1 was localized in intracellular compartments as evidenced by the resistance of most of the 35S-metabolically labeled CRSBP-1 to trypsin digestion, and by indirect immunofluorescent staining. CRSBP-1 appeared to form complexes with proteolytically processed forms (generated at and/or after the trans-Golgi network) of the v-sis gene product and with a approximately 140-kDa proteolytically cleaved form of the platelet-derived growth factor (PDGF) beta-type receptor, as demonstrated by metabolic labeling and co-immunoprecipitation. CRSBP-1, like the v-sis gene product and PDGF beta-type receptor, underwent rapid turnover which was blocked in the presence of 100 microM suramin. In normal and other transformed NIH 3T3 cells, CRSBP-1 was relatively stable and did not undergo rapid turnover and internalization/recycling at the cell surface. These results suggest that in SSV-NIH 3T3 cells, CRSBP-1 interacts with and forms ternary and binary complexes with the newly synthesized v-sis gene product and PDGF beta-type receptor at the trans-Golgi network and that the stable binary (CRSBP-1.v-sis gene product) complex is transported to the cell surface where it presents the v-sis gene product to unoccupied PDGF beta-type receptors during internalization/recycling.

Clostridium beijerinckii mutant obtained atmospheric pressure glow discharge generates enhanced electricity in a microbial fuel cell.

PubMed

Liu, Jun; Guo, Ting; Wang, Dong; Ying, Hanjie

2015-01-01

A Clostridium beijerinckii mutant M13 was derived from C. beijerinckii NCIMB 8052 by atmospheric pressure glow discharge. C. beijerinckii M13 generated a maximum output power density of 79.2 mW m(-2) and a maximum output voltage of 230 mV in a microbial fuel cell containing 1 g glucose l(-1) as carbon source and 0.15 g methyl viologen l(-1) as an electron carrier.

[Electrophysiological study on rat conduit pulmonary artery smooth muscle cells under normoxia and acute hypoxia].

PubMed

Hu, Ying; Zou, Fei; Cai, Chun-Qing; Wu, Hang-Yu; Yun, Hai-Xia; Chen, Yun-Tian; Jin, Guo-En; Ge, Ri-Li

2006-10-25

The present study was designed to investigate the electrophysiological characteristics of rat conduit pulmonary artery smooth muscle cells (PASMCs) and the response to acute hypoxia. PASMCs of the 1st to 2nd order branches in the conduit pulmonary arteries were obtained by enzymatic isolation. The PASMCs were divided into acute hypoxia preconditioned group and normoxia group. Hypoxia solutions were achieved by bubbling with 5% CO2 plus 95% N2 for at least 30 min before cell perfusion. Potassium currents were compared between these two groups using whole-cell patch clamp technique. The total outward current of PASMCs was measured under normoxia condition when iBTX [specific blocking agent of large conductance Ca-activated K(+) (BK(Ca)) channel] and 4-AP [specific blocking agent of delayed rectifier K(+) (K(DR)) channel] were added consequently into bath solution. PASMCs were classified into three types according to their size, shape and electrophysiological characteristics. Type I cells are the smallest with spindle shape, smooth surface and discrete perinuclear bulge. Type II cells show the biggest size with banana-like appearance. Type III cells have the similar size with type I, and present intermediary shape between type I and type II. iBTX had little effect on the total outward current in type I cells, while 4-AP almost completely blocked it. Most of the total outward current in type II cells was inhibited by iBTX, and the remaining was sensitive to 4-AP. In type III cells, the total outward current was sensitive to both iBTX and 4-AP. Acute hypoxia reduced the current in all three types of cells: (1614.8+/-62.5) pA to (892.4+/-33.6) pA for type I cells (P<0.01); (438.3+/-42.8) pA to (277.5+/-44.7) pA for type II cells (P<0.01); (1 042.0+/-37.2) pA to (613.6+/-23.8) pA for type III (P<0.01), and raised the resting membrane potentials (E(m)) in all these three types of cells: (-41.6+/-1.6) mV to (-18.6+/-1.5) mV (P<0.01), (-42.3+/-3.8) mV to (-30.6+/-3.0) mV (P<0.01), (-43.3+/-1.6) mV to (-28.4+/-1.4) mV (P<0.01), for type I, II, III cells, respectively. These results suggest that acute hypoxia suppresses the potassium current and improves the E(m) in PASMCs. These effects may be involved in the modulation of constriction/relaxation of conduit artery under acute hypoxia. Different distribution of K(DR) and BK(Ca) channels in these three types of PASMCs might account for their different constriction/relaxation response to acute hypoxia.

Induction of micronuclei in V79 cells after combined treatments with heterocyclic aromatic amines.

PubMed

Perez, C; Lopez de Cerain, A; Bello, J

2002-10-01

Heterocyclic aromatic amines (HAs) appear in foods rich in proteins when subjected to different cooking processes. These amines have been demonstrated to be mutagenic in bacteria; in eucaryotic cells, controversial results have been referred. The objective of this study is to evaluate the clastogenic and/or aneugenic capacity of three HAs--2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx), and 2-amino-3-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)--in isolated as well as in combined treatments. The micronucleus test in vitro was used on V79 cells in the presence and absence of metabolic activation. The duration of the treatment was 2 h, and cytochalasin B was added for 21 h to stop cytokinesis; then, micronuclei (MN) were counted in binucleated cells. In the presence of metabolic activation, the three amines showed a significant increase in the number of MN with respect to the negative control. The PhIP amine presented the highest values and it also resulted slightly active in the absence of metabolic activation, although these differences have not been considered to be significant. The combined treatments of these amines have shown that the effects attributed to them when administered together are those that are expected for a possible additive effect; the effect attributed to each HA separately is not potentiated nor inhibited.

An Investigation into III-V Compounds to Reach 20% Efficiency with Minimum Cell Thickness in Ultrathin-Film Solar Cells

NASA Astrophysics Data System (ADS)

Haque, K. A. S. M. Ehteshamul; Galib, Md. Mehedi Hassan

2013-10-01

III-V single-junction solar cells have already achieved very high efficiency levels. However, their use in terrestrial applications is limited by the high fabrication cost. High-efficiency, ultrathin-film solar cells can effectively solve this problem, as their material requirement is minimum. This work presents a comparison among several III-V compounds that have high optical absorption capability as well as optimum bandgap (around 1.4 eV) for use as solar cell absorbers. The aim is to observe and compare the ability of these materials to reach a target efficiency level of 20% with minimum possible cell thickness. The solar cell considered has an n-type ZnSe window layer, an n-type Al0.1Ga0.9As emitter layer, and a p-type Ga0.5In0.5P back surface field (BSF) layer. Ge is used as the substrate. In the initial design, a p-type InP base was sandwiched between the emitter and the BSF layer, and the design parameters for the device were optimized by analyzing the simulation outcomes with ADEPT/F, a one-dimensional (1D) simulation tool. Then, the minimum cell thickness that achieves 20% efficiency was determined by observing the efficiency variation with cell thickness. Afterwards, the base material was changed to a few other selected III-V compounds, and for each case, the minimum cell thickness was determined in a similar manner. Finally, these cell thickness values were compared and analyzed to identify more effective base layer materials for III-V single-junction solar cells.

In vitro genotoxicity of exhaust emissions of diesel and gasoline engine vehicles operated on a unified driving cycle.

PubMed

Liu, Yu-Qing; Keane, Michael; Ensell, Mang; Miller, William; Kashon, Michael; Ong, Tong-man; Mauderly, Joe; Lawson, Doug; Gautam, Mridul; Zielinska, Barbara; Whitney, Kevin; Eberhardt, James; Wallace, William

2005-01-01

Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from a set of 1998-2000 model year normal emitter diesel engine automobile or light trucks and from a set of 1982-1996 normal emitter gasoline engine automobiles or light trucks operated on the California Unified Driving Cycle at 22 [degree]C were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens for Salmonella typhimurium strains YG1024 and YG1029 on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage indicated by micronucleus induction in Chinese hamster lung fibroblasts (V79 cells), diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage in V79 cells indicated by the single cell gel electrophoresis (SCGE) assay, gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.

Garciella nitratireducens gen. nov., sp. nov., an anaerobic, thermophilic, nitrate- and thiosulfate-reducing bacterium isolated from an oilfield separator in the Gulf of Mexico.

PubMed

Miranda-Tello, Elizabeth; Fardeau, Marie-Laure; Sepúlveda, José; Fernández, Luis; Cayol, Jean-Luc; Thomas, Pierre; Ollivier, Bernard

2003-09-01

A novel Gram-positive, anaerobic and thermophilic bacterium, strain MET79(T), was isolated from an oil well located in the Gulf of Mexico. Cells were straight rods, motile by a subpolar flagellum. Spores were formed in old cultures. Inner gas vacuoles swelled the cells when exposed to air. The optimum growth conditions were 55 degrees C, pH 7.5 and 1 % NaCl. Yeast extract was required for growth. Strain MET79(T) fermented several sugars, some organic acids and Casamino acids. Glucose was fermented into lactate, acetate, butyrate, H(2) and CO(2). Strain MET79(T) reduced thiosulfate to hydrogen sulfide and nitrate to ammonium. The DNA G+C content was 30.9 mol%. The closest phylogenetic relative of strain MET79(T) was Caloranaerobacter azorensis (88.7 % 16S rDNA sequence similarity). As strain MET79(T) (=DSM 15102(T)=CIP 107615(T)) was physiologically and phylogenetically different from its closest relatives, it is assigned as the type strain of a novel species of a new genus, Garciella nitratireducens gen. nov., sp. nov.

40 CFR 79.61 - Vehicle emissions inhalation exposure guideline.

Code of Federal Regulations, 2013 CFR

2013-07-01

... of the mean weight for each sex. Animals shall be randomly assigned to treatment and control groups... the control group(s) depends on the type of study, number of biological end points used in the... evaluation of chronic effects. (v) A concurrent control group is required. This group shall be exposed to...

40 CFR 79.61 - Vehicle emissions inhalation exposure guideline.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of the mean weight for each sex. Animals shall be randomly assigned to treatment and control groups... the control group(s) depends on the type of study, number of biological end points used in the... evaluation of chronic effects. (v) A concurrent control group is required. This group shall be exposed to...

Naphthoquinones from the leaves of Rhinacanthus nasutus having acetylcholinesterase inhibitory and cytotoxic activities.

PubMed

Boonyaketgoson, Sirada; Rukachaisirikul, Vatcharin; Phongpaichit, Souwalak; Trisuwan, Kongkiat

2018-01-01

Four new naphthoquinones (1-4), named rhinacanthins S (1), T (2), U (3) and V (4), together with 13 known naphthoquinones were isolated from the leaf extract of Rhinacanthus nasutus. The structures of isolated compounds were elucidated by spectroscopic methods, especially 1D and 2D NMR spectroscopy and mass spectrometry. Rhinacanthin S (1) exhibited acetylcholinesterase inhibition activity with a % inhibition value of 48.04±3.25. The known rhinacanthin A (5) showed cytotoxicity against a MCF-7 cell line with an IC 50 value of 8.79μM, while rhinacanthin N (15) was active against the NCI-H187 cell line with an IC 50 =2.24μM and Vero cells (IC 50 =3.00μM). Copyright © 2017 Elsevier B.V. All rights reserved.

There is more than one way to turn a spherical cellular monolayer inside out: type B embryo inversion in Volvox globator

PubMed Central

2011-01-01

Background Epithelial folding is a common morphogenetic process during the development of multicellular organisms. In metazoans, the biological and biomechanical processes that underlie such three-dimensional (3D) developmental events are usually complex and difficult to investigate. Spheroidal green algae of the genus Volvox are uniquely suited as model systems for studying the basic principles of epithelial folding. Volvox embryos begin life inside out and then must turn their spherical cell monolayer outside in to achieve their adult configuration; this process is called 'inversion.' There are two fundamentally different sequences of inversion processes in Volvocaceae: type A and type B. Type A inversion is well studied, but not much is known about type B inversion. How does the embryo of a typical type B inverter, V. globator, turn itself inside out? Results In this study, we investigated the type B inversion of V. globator embryos and focused on the major movement patterns of the cellular monolayer, cell shape changes and changes in the localization of cytoplasmic bridges (CBs) connecting the cells. Isolated intact, sectioned and fragmented embryos were analyzed throughout the inversion process using light microscopy, confocal laser scanning microscopy, scanning electron microscopy and transmission electron microscopy techniques. We generated 3D models of the identified cell shapes, including the localizations of CBs. We show how concerted cell-shape changes and concerted changes in the position of cells relative to the CB system cause cell layer movements and turn the spherical cell monolayer inside out. The type B inversion of V. globator is compared to the type A inversion in V. carteri. Conclusions Concerted, spatially and temporally coordinated changes in cellular shapes in conjunction with concerted migration of cells relative to the CB system are the causes of type B inversion in V. globator. Despite significant similarities between type A and type B inverters, differences exist in almost all details of the inversion process, suggesting analogous inversion processes that arose through parallel evolution. Based on our results and due to the cellular biomechanical implications of the involved tensile and compressive forces, we developed a global mechanistic scenario that predicts epithelial folding during embryonic inversion in V. globator. PMID:22206406

α3 Chains of type V collagen regulate breast tumour growth via glypican-1

PubMed Central

Huang, Guorui; Ge, Gaoxiang; Izzi, Valerio; Greenspan, Daniel S.

2017-01-01

Pericellular α3(V) collagen can affect the functioning of cells, such as adipocytes and pancreatic β cells. Here we show that α3(V) chains are an abundant product of normal mammary gland basal cells, and that α3(V) ablation in a mouse mammary tumour model inhibits mammary tumour progression by reducing the proliferative potential of tumour cells. These effects are shown to be primarily cell autonomous, from loss of α3(V) chains normally produced by tumour cells, in which they affect growth by enhancing the ability of cell surface proteoglycan glypican-1 to act as a co-receptor for FGF2. Thus, a mechanism is presented for microenvironmental influence on tumour growth. α3(V) chains are produced in both basal-like and luminal human breast tumours, and its expression levels are tightly coupled with those of glypican-1 across breast cancer types. Evidence indicates α3(V) chains as potential targets for inhibiting tumour growth and as markers of oncogenic transformation. PMID:28102194

High-LET Radiation Induced Chromosome Aberrations in Normal and Ataxia Telangiectasia Fibroblast Cells

NASA Astrophysics Data System (ADS)

Kawata, Tetsuya; George, Ms Kerry; Cucinotta, Francis A.; Shigematsu, Naoyuki; Ito, Hisao; Furusawa, Yoshiya; Uno, Takashi

We investigated the effects of heavy ions beams on chromosomal aberrations in normal and AT cells. Normal and AT fibroblast cells arrested at G0/G1 phase were irradiated with 2 Gy of X-rays, 490 MeV/u Silicon (LET 55 keV/micron), 500 MeV/u Iron (LET 185 keV/micron) and 200 MeV/u Iron (LET 440 keV/micron) particles, and then cells were allowed to repair for 24 hours at 37 degrees before subculture. Calyculin-A induced PCC method was employed to collect G2/M chromosomes and whole DNA probes 1 and 3 were used to analyze chromosomal aberrations such as color-junctions, deletions, simple exchanges (incomplete and reciprocal exchanges) and complex-type exchanges. The percentages of aberrant cells were higher when normal and AT cells were exposed to heavy ions compared to X-rays, and had a tendency to increase with increasing LET up to 185 keV/micron and then decreased at 440 keV/micron. When the frequency of color-junctions per cell was compared after X-ray exposure, AT cells had around three times higher frequency of color-junctions (mis-rejoining) than normal cells. However, at 185 keV/micron there was no difference in the frequency of color-junctions between two cell lines. It was also found that the frequency of simple exchanges per cell was almost constant in AT cells regardless LET levels, but it was LET dependent for normal cells. Interestingly, the frequency of simple exchanges was higher for normal fibroblast cells when it was compared at 185 keV/micron, but AT cells had more complex-type exchanges at the same LET levels. Heavy ions are more efficient in inducing chromosome aberrations in normal and AT cells compared to X-rays, and the aberration types between normal and AT fibroblast appeared different probably due to difference in the ATM gene function.

Chromosome instability of HPRT-mutant subclones induced by ionising radiation of various LET.

PubMed

Govorun, R D; Koshlan, I V; Koshlan, N A; Krasavin, E A; Shmakova, N L

2002-01-01

The induction of HPRT-mutations and survival of Chinese hamster cells (line B11ii-FAF28, clone 431) were studied after irradiation by 4He and 12C-ions of various LET (20-360 keV/micrometers), produced by the U-200 heavy ion accelerator. The RBE increases with LET up to the maximum at 100-200 keV/micrometers and then decreases. Cytogenetic analysis was performed on the HPRT-mutant subclones selected from unirradiated Chinese hamster V-79 cells and from HPRT-mutant subclones that arose after exposure to gamma-rays, 1 GeV protons and 14N-ions (LET-77 keV/micrometers), produced by the synchrophasotron and the U-400M heavy ion accelerator. Slow growing mutant subclones were observed. The cytogenetic properties of individual clones were highly heterogeneous and chromosome instability was observed in both spontaneous and radiation-induced mutants. Chromosome instability was highest among spontaneous mutants and decreased with increasing LET. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Wide-Field Variability Survey of the Globular Cluster M 79 and a New Period-Luminosity Relation for SX Phe Stars

NASA Astrophysics Data System (ADS)

Kopacki, G.

2015-03-01

We present the results of a search for variable stars in a 26×39 arcmin2 field around globular cluster M 79 (NGC 1904). The search was made by means of an extended version of image subtraction, which allows us to analyze in a uniform manner CCD frames obtained with different telescopes and cameras of different sizes and resolutions. The search resulted in finding 20 new variable stars, among which 13 are cluster members. The members include one new RR Lyr star of subtype c, three SX Phe stars, and nine variable red giants. We also show that V7 is a W Vir star with a period of 13.985 d. Revised mean periods of RRab and RRc stars, ab=0.71 d and c=0.34 d, respectively, and relative percentage of RRc stars, Nc/(Nab+Nc)=45% confirm that M 79 belongs to the Oosterhoff II group of globular clusters. The mean V magnitude of the horizontal branch of M 79 based on ten RR Lyr stars has been estimated to be VHB=RR=16.11±0.03 mag. In one RRc star, V9, light changes with three close frequencies were detected, indicating excitation of nonradial modes. An SX Phe star, V18, is a double-mode pulsator with two radial modes excited, fundamental and first overtone. Moreover, we have discovered two SX Phe or δ Sct stars and one W UMa type system, all likely field objects. We also studied the period-luminosity relation for SX Phe stars. Using 62 fundamental and fundamentalized periods of radial double-mode and high-amplitude SX Phe stars known in Galactic globular clusters, we have derived the slope and zero point of this relation to be, -3.3±0.27 and 2.68±0.03 mag (at log(P/d)=-1.24), respectively.

IGF-1R inhibition induces schedule-dependent sensitization of human melanoma to temozolomide

PubMed Central

Ramcharan, Roger; Aleksic, Tamara; Kamdoum, Wilfride Petnga; Gao, Shan; Pfister, Sophia X.; Tanner, Jordan; Bridges, Esther; Asher, Ruth; Watson, Amanda J.; Margison, Geoffrey P.; Woodcock, Mick; Repapi, Emmanouela; Li, Ji-Liang; Middleton, Mark R.; Macaulay, Valentine M.

2015-01-01

Prior studies implicate type 1 IGF receptor (IGF-1R) in mediating chemo-resistance. Here, we investigated whether IGF-1R influences response to temozolomide (TMZ), which generates DNA adducts that are removed by O6-methylguanine-DNA methyltransferase (MGMT), or persist causing replication-associated double-strand breaks (DSBs). Initial assessment in 10 melanoma cell lines revealed that TMZ resistance correlated with MGMT expression (r = 0.79, p = 0.009), and in MGMT-proficient cell lines, with phospho-IGF-1R (r = 0.81, p = 0.038), suggesting that TMZ resistance associates with IGF-1R activation. Next, effects of IGF-1R inhibitors (IGF-1Ri) AZ3801 and linsitinib (OSI-906) were tested on TMZ-sensitivity, cell cycle progression and DSB induction. IGF-1Ri sensitized BRAF wild-type and mutant melanoma cells to TMZ in vitro, an effect that was independent of MGMT. Cells harboring wild-type p53 were more sensitive to IGF-1Ri, and showed schedule-dependent chemo-sensitization that was most effective when IGF-1Ri followed TMZ. This sequence sensitized to clinically-achievable TMZ concentrations and enhanced TMZ-induced apoptosis. Simultaneous or prior IGF-1Ri caused less effective chemo-sensitization, associated with increased G1 population and reduced accumulation of TMZ-induced DSBs. Clinically relevant sequential (TMZ → IGF-1Ri) treatment was tested in mice bearing A375M (V600E BRAF, wild-type p53) melanoma xenografts, achieving peak plasma/tumor IGF-1Ri levels comparable to clinical Cmax, and inducing extensive intratumoral apoptosis. TMZ or IGF-1Ri caused minor inhibition of tumor growth (gradient reduction 13%, 25% respectively), while combination treatment caused supra-additive growth delay (72%) that was significantly different from control (p < 0.01), TMZ (p < 0.01) and IGF-1Ri (p < 0.05) groups. These data highlight the importance of scheduling when combining IGF-1Ri and other targeted agents with drugs that induce replication-associated DNA damage. PMID:26497996

Functional analysis of mutations in SLC7A9, and genotype-phenotype correlation in non-Type I cystinuria.

PubMed

Font, M A; Feliubadaló, L; Estivill, X; Nunes, V; Golomb, E; Kreiss, Y; Pras, E; Bisceglia, L; d'Adamo, A P; Zelante, L; Gasparini, P; Bassi, M T; George , A L; Manzoni, M; Riboni, M; Ballabio, A; Borsani, G; Reig, N; Fernández, E; Zorzano, A; Bertran, J; Palacín, M

2001-02-15

Cystinuria (OMIM 220100) is a common recessive disorder of renal reabsorption of cystine and dibasic amino acids that results in nephrolithiasis of cystine. Mutations in SLC3A1, which encodes rBAT, cause Type I cystinuria, and mutations in SLC7A9, which encodes a putative subunit of rBAT (b(o,+)AT), cause non-Type I cystinuria. Here we describe the genomic structure of SLC7A9 (13 exons) and 28 new mutations in this gene that, together with the seven previously reported, explain 79% of the alleles in 61 non-Type I cystinuria patients. These data demonstrate that SLC7A9 is the main non-Type I cystinuria gene. Mutations G105R, V170M, A182T and R333W are the most frequent SLC7A9 missense mutations found. Among heterozygotes carrying these mutations, A182T heterozygotes showed the lowest urinary excretion values of cystine and dibasic amino acids. Functional analysis of mutation A182T after co-expression with rBAT in HeLa cells revealed significant residual transport activity. In contrast, mutations G105R, V170M and R333W are associated to a complete or almost complete loss of transport activity, leading to a more severe urinary phenotype in heterozygotes. SLC7A9 mutations located in the putative transmembrane domains of b(o,+)AT and affecting conserved amino acid residues with a small side chain generate a severe phenotype, while mutations in non-conserved residues give rise to a mild phenotype. These data provide the first genotype-phenotype correlation in non-Type I cystinuria, and show that a mild urinary phenotype in heterozygotes may associate with mutations with significant residual transport activity.

p- to n-type conductivity transition in 1.0 eV GaInNAs solar cells controlled by the V/III ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langer, Fabian, E-mail: fabian.langer@physik.uni-wuerzburg.de; Perl, Svenja; Kamp, Martin

2015-02-09

In this work, we report a p- to n-type conductivity transition of GaInNAs (1.0 eV bandgap) layers in p-i-n dilute nitride solar cells continuously controlled by the V/III ratio during growth. Near the transition region, we were able to produce GaInNAs layers with very low effective electrically active doping concentrations resulting in wide depleted areas. We obtained internal quantum efficiencies (IQEs) up to 85% at 0.2 eV above the bandgap. However, the high IQE comes along with an increased dark current density resulting in a decreased open circuit voltage of about 0.2 V. This indicates the formation of non-radiant defect centers related tomore » the p-type to n-type transition. Rapid-thermal annealing of the solar cells on the one hand helps to anneal some of these defects but on the other hand increases the effective doping concentrations.« less

Wild type measles virus attenuation independent of type I IFN.

PubMed

Druelle, Johan; Sellin, Caroline I; Waku-Kouomou, Diane; Horvat, Branka; Wild, Fabian T

2008-02-03

Measles virus attenuation has been historically performed by adaptation to cell culture. The current dogma is that attenuated virus strains induce more type I IFN and are more resistant to IFN-induced protection than wild type (wt). The adaptation of a measles virus isolate (G954-PBL) by 13 passages in Vero cells induced a strong attenuation of this strain in vivo. The adapted virus (G954-V13) differs from its parental strain by only 5 amino acids (4 in P/V/C and 1 in the M gene). While a vaccine strain, Edmonston Zagreb, could replicate equally well in various primate cells, both G954 strains exhibited restriction to the specific cell type used initially for their propagation. Surprisingly, we observed that both G954 strains induced type I IFN, the wt strain inducing even more than the attenuated ones, particularly in human plasmacytoid Dendritic Cells. Type I IFN-induced protection from the infection of both G954 strains depended on the cell type analyzed, being less efficient in the cells used to grow the viral strain. Thus, mutations in M and P/V/C proteins can critically affect MV pathogenicity, cellular tropism and lead to virus attenuation without interfering with the alpha/beta IFN system.

Wild type measles virus attenuation independent of type I IFN

PubMed Central

Druelle, Johan; Sellin, Caroline I; Waku-Kouomou, Diane; Horvat, Branka; Wild, Fabian T

2008-01-01

Background Measles virus attenuation has been historically performed by adaptation to cell culture. The current dogma is that attenuated virus strains induce more type I IFN and are more resistant to IFN-induced protection than wild type (wt). Results The adaptation of a measles virus isolate (G954-PBL) by 13 passages in Vero cells induced a strong attenuation of this strain in vivo. The adapted virus (G954-V13) differs from its parental strain by only 5 amino acids (4 in P/V/C and 1 in the M gene). While a vaccine strain, Edmonston Zagreb, could replicate equally well in various primate cells, both G954 strains exhibited restriction to the specific cell type used initially for their propagation. Surprisingly, we observed that both G954 strains induced type I IFN, the wt strain inducing even more than the attenuated ones, particularly in human plasmacytoid Dendritic Cells. Type I IFN-induced protection from the infection of both G954 strains depended on the cell type analyzed, being less efficient in the cells used to grow the viral strain. Conclusion Thus, mutations in M and P/V/C proteins can critically affect MV pathogenicity, cellular tropism and lead to virus attenuation without interfering with the α/β IFN system. PMID:18241351

Genetic analysis of a Chinese family with members affected with Usher syndrome type II and Waardenburg syndrome type IV.

PubMed

Wang, Xueling; Lin, Xiao-Jiang; Tang, Xiangrong; Chai, Yong-Chuan; Yu, De-Hong; Chen, Dong-Ye; Wu, Hao

2017-11-01

The purpose of this study was to identify the genetic causes of a family presenting with multiple symptoms overlapping Usher syndrome type II (USH2) and Waardenburg syndrome type IV (WS4). Targeted next-generation sequencing including the exon and flanking intron sequences of 79 deafness genes was performed on the proband. Co-segregation of the disease phenotype and the detected variants were confirmed in all family members by PCR amplification and Sanger sequencing. The affected members of this family had two different recessive disorders, USH2 and WS4. By targeted next-generation sequencing, we identified that USH2 was caused by a novel missense mutation, p.V4907D in GPR98; whereas WS4 due to p.V185M in EDNRB. This is the first report of homozygous p.V185M mutation in EDNRB in patient with WS4. This study reported a Chinese family with multiple independent and overlapping phenotypes. In condition, molecular level analysis was efficient to identify the causative variant p.V4907D in GPR98 and p.V185M in EDNRB, also was helpful to confirm the clinical diagnosis of USH2 and WS4. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells.

PubMed

Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

2018-02-28

We provided a new method to improve the efficiency of Sb₂S₃ thin film solar cells. The TiO₂ electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb₂S₃ solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO₂ films. Compared with the undoped TiO₂, Li-doped mesoporous TiO₂ dramatically improved the photo-voltaic performance of the thermal-evaporated Sb₂S₃ thin film solar cells, with the average power conversion efficiency ( PCE ) increasing from 1.79% to 4.03%, as well as the improved open-voltage ( V oc ), short-circuit current ( J sc ) and fill factors. The best device based on Li-doped TiO₂ achieved a power conversion efficiency up to 4.42% as well as a V oc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb₂S₃ solar cells. This study showed that Li-doping on TiO₂ can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb₂S₃-based solar cells.

Inhibition of recombinant Ca(v)3.1 (alpha(1G)) T-type calcium channels by the antipsychotic drug clozapine.

PubMed

Choi, Kee-Hyun; Rhim, Hyewhon

2010-01-25

Low voltage-activated T-type calcium channels are involved in the regulation of the neuronal excitability, and could be subject to many antipsychotic drugs. The effects of clozapine, an atypical antipsychotic drug, on recombinant Ca(v)3.1 T-type calcium channels heterologously expressed in human embryonic kidney 293 cells were examined using whole-cell patch-clamp recordings. At a standard holding potential of -100 mV, clozapine inhibited Ca(v)3.1 currents with an IC(50) value of 23.7+/-1.3 microM in a use-dependent manner. However, 10 microM clozapine inhibited more than 50% of the Ca(v)3.1 currents in recordings at a more physiologically relevant holding potential of -75 mV. Clozapine caused a significant hyperpolarizing shift in the steady-state inactivation curve of the Ca(v)3.1 channels, which is presumably the main mechanism accounting for the inhibition of the Ca(v)3.1 currents. In addition, clozapine slowed Ca(v)3.1 deactivation and inactivation kinetics but not activation kinetics. Clozapine-induced changes in deactivation and inactivation rates of the Ca(v)3.1 channel gating would likely facilitate calcium influx via Ca(v)3.1 T-type calcium channels. Thus, clozapine may exert its therapeutic and/or side effects by altering cell's excitability and firing properties through actions on T-type calcium channels.

Evaluation of photodegradation, phototoxicity and photogenotoxicity of ofloxacin in ointments with sunscreens and in solutions.

PubMed

Zgadzaj, Anna; Skrzypczak, Agata; Welenc, Ilona; Ługowska, Agnieszka; Parzonko, Andrzej; Siedlecka, Ewa; Sommer, Sylwester; Sikorska, Katarzyna; Nałęcz-Jawecki, Grzegorz

2015-03-01

Fluoroquinolones are widely used anti-bacterial agents that are known to exhibit moderate to severe phototoxicity. Furthermore some of them reveal photogenotoxicity under UV irradiation. Incidence of side effects due to light exposure may be augmented, if the medicament is used topically. The main goal of this work was to compare the extent of photodegradation of ofloxacin in ointments with various excipients: hydrated or non-hydrated base and the addition of sunscreens: bisoctrizole (Tinosorb M) and bemotrizinol (Tinosorb S). The next goal of present work was the analysis of phototoxicity and photogenotoxicity of ofloxacin photodegradation products in tested ointments and in solutions with the umu-test, the test of mitotic gene conversion with Saccharomyces cerevisiae D7 and the micronucleus assay with V79 Chinese hamster cell line. At the same time an attempt was made to determinate the photodegradation products of ofloxacin in different unguents variants. We observed a significant photoprotective effect in ointment with Tinosorb M. We did not evaluated relevant differences regarding the genotoxicity and toxicity of unguents. However, the pre-irradiated ofloxacin solutions in comparison to samples stored in the dark were significantly more genotoxic to bacteria, slightly increased the number of micronuclei in V79 cell line and were toxic to the yeast strain. Copyright © 2015 Elsevier B.V. All rights reserved.

INDUCTION OF DNA-PROTEIN CROSSLINKS BY THE METABOLISM OF DICHLOROMETHANE IN V79 CELL LINES TRANSFECTED WITH THE MURINE GLUTATHIONE-S-TRANSFERASE THETA 1 GENE

EPA Science Inventory

Dichloromethane (DCM) is considered a probable human carcinogen. Laboratory studies have shown an increased incidence of lung and liver cancer in mice but not in rats or hamsters. Despite the correlation between metabolism of DCM by the glutathione-S-transferase (GST) pathway and...

Simultaneous detection, typing and quantitation of oncogenic human papillomavirus by multiplex consensus real-time PCR.

PubMed

Jenkins, Andrew; Allum, Anne-Gry; Strand, Linda; Aakre, Randi Kersten

2013-02-01

A consensus multiplex real-time PCR test (PT13-RT) for the oncogenic human papillomavirus (HPV) types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66 is described. The test targets the L1 gene. Analytical sensitivity is between 4 and 400 GU (genomic units) in the presence of 500 ng of human DNA, corresponding to 75,000 human cells. HPV types are grouped into multiplex groups of 3 or 4 resulting in the use of 4 wells per sample and permitting up to 24 samples per run (including controls) in a standard 96-well real-time PCR instrument. False negative results are avoided by (a) measuring sample DNA concentration to control that sufficient cellular material is present and (b) including HPV type 6 as a homologous internal control in order to detect PCR inhibition or competition from other (non-oncogenic) HPV types. Analysis time from refrigerator to report is 8 h, including 2.5 h hands-on time. Relative to the HC2 test, the sensitivity and specificity were respectively 98% and 83%, the lower specificity being attributable to the higher analytical sensitivity of PT13-RT. To assess type determination comparison was made with a reversed line-blot test. Type concordance was high (κ=0.79) with discrepancies occurring mostly in multiple-positive samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Expression, crystallization and preliminary crystallographic analysis of the extracellular IgV-like domain of the human natural killer cell inhibitory receptor p75/AIRM1.

PubMed

Dimasi, Nazzareno; Moretta, Lorenzo; Biassoni, Roberto; Mariuzza, Roy A

2003-10-01

p75/AIRM1 (Siglec-7) is a sialic acid-binding Ig-like lectin recently identified as an inhibitory receptor on natural killer cells. The expression, in vitro folding, circular-dichroism spectroscopy, crystallization and preliminary X-ray characterization of the Ig-V like domain of p75/AIRM1 are reported. X-ray data were collected from a single crystal at 100 K, with a maximum useful diffraction pattern extending to 1.45 A resolution on a synchrotron source. The crystal belongs to a primitive monoclinic space group, with unit-cell parameters a = 32.65, b = 49.72, c = 39.79 A, alpha = gamma = 90, beta = 113 degrees. The systematic absences indicate that the space group is P2(1). Assuming one molecule per asymmetric unit, V(M) (the Matthews coefficient) was calculated to be 1.879 A(3) Da(-1) and the solvent content was estimated to be 32.01%.

Cytotoxic effects of glass ionomer cements on human dental pulp stem cells correlate with fluoride release.

PubMed

Kanjevac, Tatjana; Milovanovic, Marija; Volarevic, Vladislav; Lukic, Miodrag L; Arsenijevic, Nebojsa; Markovic, Dejan; Zdravkovic, Nebojsa; Tesic, Zivoslav; Lukic, Aleksandra

2012-01-01

Glass ionomer cements (GICs) are commonly used as restorative materials. Responses to GICs differ among cell types and it is therefore of importance to thoroughly investigate the influence of these restorative materials on pulp stem cells that are potential source for dental tissue regeneration. Eight biomaterials were tested: Fuji I, Fuji II, Fuji VIII, Fuji IX, Fuji Plus, Fuji Triage, Vitrebond and Composit. We compared their cytotoxic activity on human dental pulp stem cells (DPSC) and correlated this activity with the content of Fluoride, Aluminium and Strontium ions in their eluates. Elution samples of biomaterials were prepared in sterile tissue culture medium and the medium was tested for toxicity by an assay of cell survival/proliferation (MTT test) and apoptosis (Annexin V FITC Detection Kit). Concentrations of Fluoride, Aluminium and Strontium ions were tested by appropriate methods in the same eluates. Cell survival ranged between 79.62% (Fuji Triage) to 1.5% (Fuji Plus) and most dead DPSCs were in the stage of late apoptosis. Fluoride release correlated with cytotoxicity of GICs, while Aluminium and Strontium ions, present in significant amount in eluates of tested GICs did not. Fuji Plus, Vitrebond and Fuji VIII, which released fluoride in higher quantities than other GICs, were highly toxic to human DPSCs. Opposite, low levels of released fluoride correlated to low cytotoxic effect of Composit, Fuji I and Fuji Triage.

Biological activities of phthalocyanines--XVI. Tetrahydroxy- and tetraalkylhydroxy zinc phthalocyanines. Effect of alkyl chain length on in vitro and in vivo photodynamic activities.

PubMed Central

Boyle, R. W.; Leznoff, C. C.; van Lier, J. E.

1993-01-01

Zinc phthalocyanine substituted with four hydroxyl groups attached to the macrocycle, either directly or via spacer chains of three or six carbon atoms, were tested for their photodynamic ability to inactivate Chinese hamster lung fibroblasts (line V-79) in vitro, and to induce regression of EMT-6 tumours grown subcutaneously in Balb/c mice. Their potential to inflict direct cell killing during photodynamic therapy was investigated by examining vascular stasis immediately following photoirradiation using fluorescein as a marker, and also by an in vivo/in vitro EMT-6 cell survival assay. Both of the tetraalkylhydroxy substituted zinc phthalocyanines are effective photodynamic sensitisers in vivo with the tetrapropylhydroxy compound exhibiting about twice the activity of the tetrahexylhydroxy analogue. The differences in activities were accentuated in vitro, the tetrapropylhydroxy compound was two orders of magnitude more potent than the tetrahexylhydroxy analogue in photoinactivating V-79 cells. The tetrahydroxy compound lacking spacer chains failed to exhibit photodynamic activity in either system. Tumour response with the active compounds was preceded by vascular stasis immediate following irradiation which suggests, together with the absence of activity in the in vivo/in vitro assay, that tumour regression involves an indirect response to the photodynamic action rather than direct cell killing. These data demonstrate the importance of the spatial orientation of functional groups around the macrocycle of photosensitisers for their efficacy in the photodynamic therapy of cancer. PMID:8512803

Effect of Sn addition on glassy Si-Te bulk sample

NASA Astrophysics Data System (ADS)

Babanna, Jagannatha K.; Roy, Diptoshi; Varma, Sreevidya G.; Asokan, Sundarrajan; Das, Chandasree

2018-05-01

Bulk Si20Te79Sn1 glass is prepared by melt-quenching method, amorphous nature of the as-quenched glass is confirmed by XRD. I-V characteristics reveals that Si20Te79Sn1 bulk sample exhibits threshold type electrical switching behavior. The thermal parameters such as crystallization temperature, glass transition temperature are obtained using differential scanning calorimetry. The crystalline peak study of the sample annealed at crystallization temperature for 2 hr shows that the Sn atom interact with Si or Te but do not interact with the Si-Te matrix in a greater extent and it forms a separate phase network individually.

[The protective role of postvaccinal immunity in mumps in children].

PubMed

Zheleznikova, G F; Ivanova, V V; Bekhtereva, M K; Gnilevskaia, Z U; Monakhova, N E; Novozhilova, E V; Goleva, O V; Sizemov, A N

2000-01-01

The immunological study of children with infectious parotitis (IP) without complications and with such complications as pancreatitis, meningitis or orchitis in the glandular form was carried out. In accordance with the previously proposed principle, 4 types of immune response (IR) were established on the basis of differences in initial resistance and the IR profile: cell-mediated immunity (types I and III) and humoral immunity (types II and IV). The patients included nonvaccinated children, as well as children vaccinated on epidemic indications, 3-6, 7-9, 10 and more years before infection. The comparative analysis of the number of IP cases with and without complications in the groups of children, divided according to their immunization history and the type of IR, revealed that postvaccinal immunity in children vaccinated on epidemic indications (less than a month ago) or 3-6 years before infection had protective potential, sufficient for the prevention of complicated forms of IP. Immunity obtained 7-9 years ago was effective for the protection from IP complications only in cell-mediated, but not humoral IR. Postvaccinal immunity obtained more than 10 years ago did not ensure the decrease in the occurrence of complicated forms of IP (in comparison with that in nonvaccinated patients) in children with any type of IR.

Grissom AFB, Indiana. Revised Uniform Summary of Surface Weather Observations. Parts A-F.

DTIC Science & Technology

1987-11-01

PERIOD OF RECORD: 78-B7 MONTH: MAR HOUSILSTI: ISO -1700 CE ILIOO V|SIBIL1TV IN SIATUTE MILES IN I GE GE GE GE GE GE GE GE GE GE GE GE GE GC GE GE FEET I...77.9 77.9 77.9 77.9 77.9 77.9 77.9 GE200:52 14 748 7.3 7. 79:1 79.4 79.4 79.6 79:7 79:7 79:7 79.7 79.7 79.7 79.74E 27001 25. 7 T4.7 78.2, 91.1 62.4...82175. ’.1. 1 *- I. p ’X k,’ 33U-CS I SD 13.712 15.2?’. 51.51. 10 09? 1k I-j6; b.Z* b.6i k.450,~ 9 Ia..’ I * ISO ? 0S1 921 646 #;v 9: 𔄃 $0 49 vs t7 * P LAN

Boron Doped Nanocrystalline Film with Improved Work Function as a Buffer Layer in Thin Film Silicon Solar Cells.

PubMed

Park, Jinjoo; Shin, Chonghoon; Park, Hyeongsik; Jung, Junhee; Lee, Youn-Jung; Bong, Sungjae; Dao, Vinh Ai; Balaji, Nagarajan; Yi, Junsin

2015-03-01

We investigated thin film silicon solar cells with boron doped hydrogenated nanocrystalline silicon/ hydrogenated amorphous silicon oxide [p-type nc-Si:H/a-SiOx:H] layer. First, we researched the bandgap engineering of diborane (B2H6) doped wide bandgap hydrogenated nanocryslline silicon (p-type nc-Si:H) films, which have excellent electrical properties of high dark conductivity, and low activation energy. The films prepared with lower doping ratio and higher hydrogen dilution ratio had higher optical gap (Eg), with higher dark conductivity (σ(d)), and lower activation energy (Ea). We controlled Eg from 2.10 eV to 1.75 eV, with σ(d) from 1.1 S/cm to 7.59 x 10(-3) S/cm, and Ea from 0.040 eV to 0.128 eV. Next, we focused on the fabrication of thin film silicon solar cells. By inserting p-type nc-Si:H film into the thin film silicon solar cells, we achieved a remarkable increase in the built-in potential from 0.803 eV to 0.901 eV. By forming p-type nc-Si:H film between SnO2:F/ZnO:Al (30 nm) and p-type a-SiOx:H layer, the solar cell properties of open circuit voltage (Voc), short circuit current density (Jsc), and efficiency (η) were improved by 3.7%, 9.2%, and 9.8%, respectively.

Minisatellite and Hprt mutations in V79 cells irradiated with helium ions and gamma rays.

PubMed

Cherubinit, R; Canova, S; Favaretto, S; Bruna, V; Battivelli, P; Celotti, L

2002-09-01

To evaluate and compare cytotoxic and mutational effects of graded doses of gamma-rays and 4He++ ions at different LET values (nominally 80 and 123 keV/microm) in V79 cells. 4He++ ion beams at 80 and 123 keV/microm were supplied by the 7 MV Van de Graaff CN accelerator of the INFN-LNL in the dose range 0.3 2.4 Gy at a dose rate of 1 Gy/min. Gamma-irradiation was performed by the 60Co 'gamma beam' of CNR-FRAE (at the INFN-LNL) in the dose range 0.5 6.0 Gy at a dose rate of 1 Gy/min. After irradiation, the cells were seeded to measure surviving fraction (SF) and mutant frequency (MF) at the Hprt locus on the basis of 6-thioguanine resistance. Alterations at minisatellite sequences (MS) of clones derived from irradiated and unirradiated cells were detected by Southern blot analysis using a multi-locus probe (DNA fingerprinting). Survival data from 4He++ irradiation at two LET values (80 and 123 keV/microm) yielded similar results: alpha = (1.08 +/- 0.04)/Gy and (0.90 +/- 0.03)/Gy, respectively. The best fit for mutant induction at the Hprt locus after 80keV/microm 4He++ was a linear function of the dose in the dose-interval 0-1.5 Gy: alpha= (47.77 +/- 16.01) x 10(-6)/Gy. The best fit for mutant induction after 123 keV/microm 4He++ in the dose-interval 0-1.2 Gv was a linear-quadratic function: alpha=(86.01 +/- 13.80) x 10(-6)/Gy; beta = (42.87 +/- 11.03) x 10(-6)/Gy2. For gamma-irradiation, the best fit of Hprt mutation data gave: alpha = (4.14+2.67)x 10(-6)/Gy: beta = (0.63 +/- 0.86) x 10(-6)/Gy2. The best fitting of MS alteration data with linear-quadratic or linear relationships gave: for gamma-rays, alpha = 0.56 mutants/Gy and beta = 0.52 mutants/Gy2; for 80 keV/microm 4He++, alpha = 3.70 mutants/Gy and beta = 9.00 mutants/Gy2; for 123keV/microm 4He++, alpha = 4.36 mutants/Gy. The results reported here confirmed the higher cytotoxic and mutagenic effects of helium ions in comparison with gamma-irradiation and the ability of DNA fingerprint analysis to investigate DNA damage induced by different ionizing radiations. The results of the mutagenic effects measured by the two tests are in agreement.

AKAP79/150 impacts intrinsic excitability of hippocampal neurons through phospho-regulation of A-type K+ channel trafficking.

PubMed

Lin, Lin; Sun, Wei; Kung, Faith; Dell'Acqua, Mark L; Hoffman, Dax A

2011-01-26

Kv4.2, as the primary α-subunit of rapidly inactivating, A-type voltage-gated K(+) (Kv) channels expressed in hippocampal CA1 pyramidal dendrites, plays a critical role in regulating their excitability. Activity-dependent trafficking of Kv4.2 relies on C-terminal protein kinase A (PKA) phosphorylation. A-kinase-anchoring proteins (AKAPs) target PKA to glutamate receptor and ion channel complexes to allow for discrete, local signaling. As part of a previous study, we showed that AKAP79/150 interacts with Kv4.2 complexes and that the two proteins colocalize in hippocampal neurons. However, the nature and functional consequence of their interaction has not been previously explored. Here, we report that the C-terminal domain of Kv4.2 interacts with an internal region of AKAP79/150 that overlaps with its MAGUK (membrane-associated guanylate kinase)-binding domain. We show that AKAP79/150-anchored PKA activity controls Kv4.2 surface expression in heterologous cells and hippocampal neurons. Consistent with these findings, disrupting PKA anchoring led to a decrease in neuronal excitability, while preventing dephosphorylation by the phosphatase calcineurin resulted in increased excitability. These results demonstrate that AKAP79/150 provides a platform for dynamic PKA regulation of Kv4.2 expression, fundamentally impacting CA1 excitability.

Osteoblast response to porous titanium and biomimetic surface: In vitro analysis.

PubMed

Prado, Renata Falchete do; de Oliveira, Fernanda Saraiva; Nascimento, Rodrigo Dias; de Vasconcellos, Luana Marotta Reis; Carvalho, Yasmin Rodarte; Cairo, Carlos Alberto Alves

2015-01-01

This study analyzed the behavior of human osteoblasts cultured on porous titanium specimens, with and without biomimetic treatment, compared to dense titanium. The experiment had seven groups: Group 1: cells cultured on polystyrene of culture plate wells; Group 2: cells cultured on dense titanium specimen; Group 3: specimen with 33.79% of pores; Group 4: 41.79% of pores; Groups 5, 6 and 7: specimens similar to groups 2, 3 and 4, yet with biomimetic treatment. Real time-polymerase chain reaction with reverse transcription of the following genes was performed: prostaglandin E2 synthase, integrin β1, osterix, Runx2, Interleukin 6, macrophage colony stimulating factor, apolipoprotein E and others. The study achieved data on cell adhesion, growth and viability, total protein content, alkaline phosphatase activity and quantity of mineralized nodule formations. Data were statistically evaluated. Adherent cells and alkaline phosphatase activity were similar in titanium specimens, regardless of the groups. Biomimetic treatment reduced the total protein activity and the viability of tested cells. Most tested genes had statistically similar expression in all groups. The tested porosities did not cause alterations in osteoblast behavior and the biomimetic treatment impaired the biocompatibility of titanium causing cytotoxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

Positive anodic poised potential regulates microbial fuel cell performance with the function of open and closed circuitry.

PubMed

Srikanth, S; Venkata Mohan, S; Sarma, P N

2010-07-01

Positive influence of poised potential on microbial fuel cell (MFC) performance was observed with increase in the applied potential up to 600 mV and decreased thereafter. Higher power output (79.33 mW/m(2)) was observed at 600 mV poised potential under open circuit operation (OC). Closed circuit operation (CC) showed almost negligible power output due to continuous electron discharge against an external load (100 Omega). However, CC operation resulted in the higher substrate (chemical oxygen demand (COD)) degradation [61.23% (control); 70.46% (OC; 600 mV); 74.15% (CC; 600 mV)] and total dissolved solids (TDS) removal [29.17% (control); 43.75% (OC; 600 mV); 72.92% (CC; 600 mV)] efficiencies compared to OC. Electron discharge and energy conversion efficiency was also observed to be higher with 600 mV poised potential. Poising potential showed additional redox couples (-0.29+/-0.05 mV) on cyclic voltammetry. Application of poised potential during startup phase will help to enrich electrochemically active consortia on anode resulting in improved performance of MFC. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

B cell receptor accessory molecule CD79α: Characterisation and expression analysis in a cartilaginous fish, the spiny dogfish (Squalus acanthias)

PubMed Central

Li, Ronggai; Wang, Tiehui; Bird, Steve; Zou, Jun; Dooley, Helen; Secombes, Christopher J.

2013-01-01

CD79α (also known as Igα) is a component of the B cell antigen receptor complex and plays an important role in B cell signalling. The CD79α protein is present on the surface of B cells throughout their life cycle, and is absent on all other healthy cells, making it a highly reliable marker for B cells in mammals. In this study the spiny dogfish (Squalus acanthias) CD79α (SaCD79α) is described and its expression studied under constitutive and stimulated conditions. The spiny dogfish CD79α cDNA contains an open reading frame of 618 bp, encoding a protein of 205 amino acids. Comparison of the SaCD79α gene with that of other species shows that the gross structure (number of exons, exon/intron boundaries, etc.) is highly conserved across phylogeny. Additionally, analysis of the 5′ flanking region shows SaCD79α lacks a TATA box and possesses binding sites for multiple transcription factors implicated in its B cell-specific gene transcription in other species. Spiny dogfish CD79α is most highly expressed in immune tissues, such as spleen, epigonal and Leydig organ, and its transcript level significantly correlates with those of spiny dogfish immunoglobulin heavy chains. Additionally, CD79α transcription is up-regulated, to a small but significant degree, in peripheral blood cells following stimulation with pokeweed mitogen. These results strongly indicate that, as in mammals, spiny dogfish CD79α is expressed by shark B cells where it associates with surface-bound immunoglobulin to form a fully functional BCR, and thus may serve as a pan-B cell marker in future shark immunological studies. PMID:23454429

B cell receptor accessory molecule CD79α: characterisation and expression analysis in a cartilaginous fish, the spiny dogfish (Squalus acanthias).

PubMed

Li, Ronggai; Wang, Tiehui; Bird, Steve; Zou, Jun; Dooley, Helen; Secombes, Christopher J

2013-06-01

CD79α (also known as Igα) is a component of the B cell antigen receptor complex and plays an important role in B cell signalling. The CD79α protein is present on the surface of B cells throughout their life cycle, and is absent on all other healthy cells, making it a highly reliable marker for B cells in mammals. In this study the spiny dogfish (Squalus acanthias) CD79α (SaCD79α) is described and its expression studied under constitutive and stimulated conditions. The spiny dogfish CD79α cDNA contains an open reading frame of 618 bp, encoding a protein of 205 amino acids. Comparison of the SaCD79α gene with that of other species shows that the gross structure (number of exons, exon/intron boundaries, etc.) is highly conserved across phylogeny. Additionally, analysis of the 5' flanking region shows SaCD79α lacks a TATA box and possesses binding sites for multiple transcription factors implicated in its B cell-specific gene transcription in other species. Spiny dogfish CD79α is most highly expressed in immune tissues, such as spleen, epigonal and Leydig organ, and its transcript level significantly correlates with those of spiny dogfish immunoglobulin heavy chains. Additionally, CD79α transcription is up-regulated, to a small but significant degree, in peripheral blood cells following stimulation with pokeweed mitogen. These results strongly indicate that, as in mammals, spiny dogfish CD79α is expressed by shark B cells where it associates with surface-bound immunoglobulin to form a fully functional BCR, and thus may serve as a pan-B cell marker in future shark immunological studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Classifying GABAergic interneurons with semi-supervised projected model-based clustering.

PubMed

Mihaljević, Bojan; Benavides-Piccione, Ruth; Guerra, Luis; DeFelipe, Javier; Larrañaga, Pedro; Bielza, Concha

2015-09-01

A recently introduced pragmatic scheme promises to be a useful catalog of interneuron names. We sought to automatically classify digitally reconstructed interneuronal morphologies according to this scheme. Simultaneously, we sought to discover possible subtypes of these types that might emerge during automatic classification (clustering). We also investigated which morphometric properties were most relevant for this classification. A set of 118 digitally reconstructed interneuronal morphologies classified into the common basket (CB), horse-tail (HT), large basket (LB), and Martinotti (MA) interneuron types by 42 of the world's leading neuroscientists, quantified by five simple morphometric properties of the axon and four of the dendrites. We labeled each neuron with the type most commonly assigned to it by the experts. We then removed this class information for each type separately, and applied semi-supervised clustering to those cells (keeping the others' cluster membership fixed), to assess separation from other types and look for the formation of new groups (subtypes). We performed this same experiment unlabeling the cells of two types at a time, and of half the cells of a single type at a time. The clustering model is a finite mixture of Gaussians which we adapted for the estimation of local (per-cluster) feature relevance. We performed the described experiments on three different subsets of the data, formed according to how many experts agreed on type membership: at least 18 experts (the full data set), at least 21 (73 neurons), and at least 26 (47 neurons). Interneurons with more reliable type labels were classified more accurately. We classified HT cells with 100% accuracy, MA cells with 73% accuracy, and CB and LB cells with 56% and 58% accuracy, respectively. We identified three subtypes of the MA type, one subtype of CB and LB types each, and no subtypes of HT (it was a single, homogeneous type). We got maximum (adapted) Silhouette width and ARI values of 1, 0.83, 0.79, and 0.42, when unlabeling the HT, CB, LB, and MA types, respectively, confirming the quality of the formed cluster solutions. The subtypes identified when unlabeling a single type also emerged when unlabeling two types at a time, confirming their validity. Axonal morphometric properties were more relevant that dendritic ones, with the axonal polar histogram length in the [π, 2π) angle interval being particularly useful. The applied semi-supervised clustering method can accurately discriminate among CB, HT, LB, and MA interneuron types while discovering potential subtypes, and is therefore useful for neuronal classification. The discovery of potential subtypes suggests that some of these types are more heterogeneous that previously thought. Finally, axonal variables seem to be more relevant than dendritic ones for distinguishing among the CB, HT, LB, and MA interneuron types. Copyright © 2015 Elsevier B.V. All rights reserved.

Electricity generation and modeling of microbial fuel cell from continuous beer brewery wastewater.

PubMed

Wen, Qing; Wu, Ying; Cao, Dianxue; Zhao, Lixin; Sun, Qian

2009-09-01

Electricity production and modeling of microbial fuel cell (MFC) from continuous beer brewery wastewater was studied in this paper. A single air-cathode MFC was constructed, carbon fiber was used as anode and diluted brewery wastewater (COD=626.58 mg/L) as substrate. The MFC displayed an open-circuit voltage of 0.578 V and a maximum power density of 9.52 W/m(3) (264 mW/m(2)). Using the model based on polarization curve, various voltage losses were quantified. At current density of 1.79 A/m(2), reaction kinetic loss and mass transport loss both achieved to 0.248 V; while ohmic loss was 0.046 V. Results demonstrated that it was feasible and stable for producing bioelectricity from brewery wastewater; while the most important factors which influenced the performance of the MFC are reaction kinetic loss and mass transport loss.

MYC copy number gains are associated with poor outcome in penile squamous cell carcinoma.

PubMed

Masferrer, Emili; Ferrándiz-Pulido, Carla; Lloveras, Belén; Masferrer-Niubò, Magalí; Espinet, Blanca; Salido, Marta; Rodríguez-Rivera, María; Alemany, Laia; Placer, Jose; Gelabert, Antoni; Servitje, Octavi; García-Patos, Vicenç; Pujol, Ramon M; Toll, Agustí

2012-11-01

We determined MYC gene numerical aberrations and protein expression at different stages of penile squamous cell carcinoma carcinogenesis. We correlated these findings with clinicopathological parameters and HPV infection. We evaluated 79 cases of penile squamous cell carcinoma, including 11 in situ and 68 invasive carcinomas. The MYC cytogenetic profile was evaluated by fluorescence in situ hybridization. HPV was detected by polymerase chain reaction amplification. MYC gains were identified in 4 of 11 in situ carcinomas (36%) and 50 of 68 invasive penile squamous cell carcinomas (73%). A significant association between MYC gains, and tumor progression and poor outcome was demonstrated (p <0.05). HPV DNA was detected in 32 of 79 penile squamous cell carcinomas (39%). High risk type 16 was the most prevalent type. MYC numerical aberrations did not correlate with HPV status. A significant association between HPV and MYC protein over expression was noted. In HPV negative cases MYC gains correlated with MYC over expression. MYC gains progressively increased during penile squamous cell carcinoma progression from in situ samples to metastases. MYC gains were an independent factor for poor prognosis. These findings were independent of HPV infection. MYC expression was increased in samples with HPV infection, probably reflecting direct activation of MYC. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

SC79 protects retinal pigment epithelium cells from UV radiation via activating Akt-Nrf2 signaling

PubMed Central

Cao, Guo-fan; Cao, Cong; Jiang, Qin

2016-01-01

Excessive Ultra-violet (UV) radiation causes oxidative damages and apoptosis in retinal pigment epithelium (RPE) cells. Here we tested the potential activity of SC79, a novel small molecule activator of Akt, against the process. We showed that SC79 activated Akt in primary and established (ARPE-19 line) RPE cells. It protected RPE cells from UV damages possibly via inhibiting cell apoptosis. Akt inhibition, via an Akt specific inhibitor (MK-2206) or Akt1 shRNA silence, almost abolished SC79-induced RPE cytoprotection. Further studies showed that SC79 activated Akt-dependent NF-E2-related factor 2 (Nrf2) signaling and inhibited UV-induced oxidative stress in RPE cells. Reversely, Nrf2 shRNA knockdown or S40T mutation attenuated SC79-induced anti-UV activity. For the in vivo studies, we showed that intravitreal injection of SC79 significantly protected mouse retina from light damages. Based on these results, we suggest that SC79 protects RPE cells from UV damages possibly via activating Akt-Nrf2 signaling axis. PMID:27517753

Human parainfluenza virus type 2 V protein inhibits caspase-1.

PubMed

Ohta, Keisuke; Matsumoto, Yusuke; Nishio, Machiko

2018-04-01

The multifunctional V protein of human parainfluenza virus type 2 (hPIV2) plays important roles in controlling viral genome replication, inhibiting the host interferon response and promoting virus growth. We screened a yeast two-hybrid library using V protein as bait to identify host factors that are important for other functions of V. One of several positive clones isolated from HeLa cell-derived cDNA library encodes caspase-1. We found that the C-terminal region of V interacts with the C-terminal region of caspase-1 in mammalian cells. Moreover, the V protein repressed caspase-1 activity and the formation of interleukin-1β (IL-1β) in a dose-dependent manner. IL-1β secretion induced by wild-type hPIV2 infection in human monocytic THP-1 cells was significantly lower than that induced by recombinant hPIV2 lacking V protein or having a mutant V. These data suggest that hPIV2 V protein inhibits caspase-1-mediated maturation of IL-1β via its interaction with caspase-1.

Hemagglutinin-specific neutralization of subacute sclerosing panencephalitis viruses

PubMed Central

Muller, Claude P.; Russell, Stephen J.

2018-01-01

Subacute sclerosing panencephalitis (SSPE) is a progressive, lethal complication of measles caused by particular mutants of measles virus (MeV) that persist in the brain despite high levels of neutralizing antibodies. We addressed the hypothesis that antigenic drift is involved in the pathogenetic mechanism of SSPE by analyzing antigenic alterations in the MeV envelope hemagglutinin protein (MeV-H) found in patients with SSPE in relation to major circulating MeV genotypes. To this aim, we obtained cDNA for the MeV-H gene from tissue taken at brain autopsy from 3 deceased persons with SSPE who had short (3–4 months, SMa79), average (3.5 years, SMa84), and long (18 years, SMa94) disease courses. Recombinant MeVs with a substituted MeV-H gene were generated by a reverse genetic system. Virus neutralization assays with a panel of anti-MeV-H murine monoclonal antibodies (mAbs) or vaccine-immunized mouse anti-MeV-H polyclonal sera were performed to determine the antigenic relatedness. Functional and receptor-binding analysis of the SSPE MeV-H showed activity in a SLAM/nectin-4–dependent manner. Similar to our panel of wild-type viruses, our SSPE viruses showed an altered antigenic profile. Genotypes A, G3, and F (SSPE case SMa79) were the exception, with an intact antigenic structure. Genotypes D7 and F (SSPE SMa79) showed enhanced neutralization by mAbs targeting antigenic site IIa. Genotypes H1 and the recently reported D4.2 were the most antigenically altered genotypes. Epitope mapping of neutralizing mAbs BH015 and BH130 reveal a new antigenic site on MeV-H, which we designated Φ for its intermediate position between previously defined antigenic sites Ia and Ib. We conclude that SSPE-causing viruses show similar antigenic properties to currently circulating MeV genotypes. The absence of a direct correlation between antigenic changes and predisposition of a certain genotype to cause SSPE does not lend support to the proposed antigenic drift as a pathogenetic mechanism in SSPE. PMID:29466428

Hemagglutinin-specific neutralization of subacute sclerosing panencephalitis viruses.

PubMed

Muñoz-Alía, Miguel Ángel; Muller, Claude P; Russell, Stephen J

2018-01-01

Subacute sclerosing panencephalitis (SSPE) is a progressive, lethal complication of measles caused by particular mutants of measles virus (MeV) that persist in the brain despite high levels of neutralizing antibodies. We addressed the hypothesis that antigenic drift is involved in the pathogenetic mechanism of SSPE by analyzing antigenic alterations in the MeV envelope hemagglutinin protein (MeV-H) found in patients with SSPE in relation to major circulating MeV genotypes. To this aim, we obtained cDNA for the MeV-H gene from tissue taken at brain autopsy from 3 deceased persons with SSPE who had short (3-4 months, SMa79), average (3.5 years, SMa84), and long (18 years, SMa94) disease courses. Recombinant MeVs with a substituted MeV-H gene were generated by a reverse genetic system. Virus neutralization assays with a panel of anti-MeV-H murine monoclonal antibodies (mAbs) or vaccine-immunized mouse anti-MeV-H polyclonal sera were performed to determine the antigenic relatedness. Functional and receptor-binding analysis of the SSPE MeV-H showed activity in a SLAM/nectin-4-dependent manner. Similar to our panel of wild-type viruses, our SSPE viruses showed an altered antigenic profile. Genotypes A, G3, and F (SSPE case SMa79) were the exception, with an intact antigenic structure. Genotypes D7 and F (SSPE SMa79) showed enhanced neutralization by mAbs targeting antigenic site IIa. Genotypes H1 and the recently reported D4.2 were the most antigenically altered genotypes. Epitope mapping of neutralizing mAbs BH015 and BH130 reveal a new antigenic site on MeV-H, which we designated Φ for its intermediate position between previously defined antigenic sites Ia and Ib. We conclude that SSPE-causing viruses show similar antigenic properties to currently circulating MeV genotypes. The absence of a direct correlation between antigenic changes and predisposition of a certain genotype to cause SSPE does not lend support to the proposed antigenic drift as a pathogenetic mechanism in SSPE.

Glycans coated silver nanoparticles induces autophagy and necrosis in HeLa cells

NASA Astrophysics Data System (ADS)

Panzarini, Elisa; Mariano, Stefania; Dini, Luciana

2015-06-01

This study reports the induction of autophagy by two concentrations (2×103 or 2×104 NPs/cell) of 30 nm sized β-D-Glucose- and β-D-Glucose/Sucrose-coated silver NanoParticles (AgNPs-G and AgNPs-GS respectively) in HeLa cells treated for 6, 12, 24 and 48 hrs. Cell viability was assessed by Neutral Red (NR) test and morphological evaluation. In addition ROS generation (NBT test) and induction of apoptosis/necrosis (Annexin V/Propidium Iodide-Annexin V/PI staining) and autophagy (Monodansylcadaverine-MDC staining) were evaluated. Cytotoxicity, ROS generation and morphology changes depend on NPs type and amount, and incubation time. As a general result, AgNPs-G are more toxic than AgNPs-GS. Moreover, the lowest AgNPs-GS concentration is ineffective on cell viability and ROS generation. Only 10% and 25% of viable HeLa cells were found at the end of incubation time in the presence of higher amount of AgNPs - G and AgNPs-GS respectively and in parallel ROS generation is induced. To elucidate the type of cell death, Annexin V/PI and MDC staining was performed. Interestingly, irrespective of coating type and NPs amount the percentage of apoptotic cells (Annexin V+/PI-) is similar to viable HeLa cells. At contrary, we observed a NPs amount dependent autophagy and necrosis induction. In fact, the lower amount of NPs induces autophagy (MDC+/PI- cells) whereas the higher one induces necrosis (Annexin V+/PI+ cells). Our findings suggest that AgNPs-induced cytotoxicity depends on AgNPs amount and type and provide preliminary evidence of induction of autophagy in HeLa cells cultured in the presence of AgNPs.

Apoptosis induced by cold shock in vitro is dependent on cell growth phase.

PubMed

Soloff, B L; Nagle, W A; Moss, A J; Henle, K J; Crawford, J T

1987-06-15

Chinese hamster V79 fibroblast cells were exposed to brief periods of cold but non-freezing temperatures at different points on the population growth curve. Upon rewarming, cells at the transition from logarithmic to stationary growth exhibited apoptosis (programmed cell death). Cells in other stages of growth, or after reentry into logarithmic growth by refeeding, did not exhibit apoptosis. Apoptosis was expressed by marked cytoplasmic blebbing, by a characteristic non-random fragmentation of DNA into nucleosomal-sized pieces, and by loss of colony-forming ability. The data suggest that cold shock served as a stimulus for susceptible cells to undergo apoptosis. Thus, the experiments describe a new in vitro system for studying the mechanisms of apoptosis.

Integrin expression and glycosylation patterns regulate cell-matrix adhesion and alter with breast cancer progression.

PubMed

Singh, Chandrajeet; Shyanti, Ritis K; Singh, Virendra; Kale, Raosaheb K; Mishra, Jai P N; Singh, Rana P

2018-05-05

Integrins are the major cell adhesion glycoproteins involved in cell-extracellular matrix (ECM) interaction and metastasis. Further, glycosylation on integrin is necessary for its proper folding and functionality. Herein, differential expression of integrins viz., αvβ3 and αvβ6 was examined in MDA-MB-231, MDA-MB-468 and MCF-10A cells, which signify three different stages of breast cancer development from highly metastatic to non-tumorigenic stage. The expression of αvβ3 and αvβ6 integrins at mRNA and protein levels was observed in all three cell lines and the results displayed a distinct pattern of expression. Highly metastatic cells showed enhanced expression of αvβ3 than moderate metastatic and non-tumorigenic cells. The scenario was reversed in case of αvβ6 integrin, which was strongly expressed in moderate metastatic and non-tumorigenic cells. N-glycosylation of αvβ3 and αvβ6 integrins is required for the attachment of cells to ECM proteins like fibronectin. The cell adhesion properties were found to be different in these cancer cells with respect to the type of integrins expressed. The results testify that αvβ3 integrin in highly metastatic cells, αvβ6 integrin in both moderate metastatic and non-tumorigenic cells play an important role in cell adhesion. The investigation typify that N-glycosylation on integrins is also necessary for cell-ECM interaction. Further, glycosylation inhibition by Swainsonine is found to be more detrimental to invasive property of moderate metastatic cells. Conclusively, types of integrins expressed as well as their N-glycosylation pattern alter during the course of breast cancer progression. Copyright © 2018 Elsevier Inc. All rights reserved.

Regulation of vacuolar H{sup +}-ATPase in microglia by RANKL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serrano, Eric M.; Ricofort, Ryan D.; Zuo, Jian

2009-11-06

Vacuolar H{sup +}-ATPases (V-ATPases) are large electrogenic proton pumps composed of numerous subunits that play vital housekeeping roles in the acidification of compartments of the endocytic pathway. Additionally, V-ATPases play specialized roles in certain cell types, a capacity that is linked to cell type selective expression of isoforms of some of the subunits. We detected low levels of the a3 isoform of the a-subunit in mouse brain extracts. Examination of various brain-derived cell types by immunoblotting showed a3 was expressed in the N9 microglia cell line and in primary microglia, but not in other cell types. The expression of a3more » in osteoclasts requires stimulation by Receptor Activator of Nuclear Factor {kappa}B-ligand (RANKL). We found that Receptor Activator of Nuclear Factor {kappa}B (RANK) was expressed by microglia. Stimulation of microglia with RANKL triggered increased expression of a3. V-ATPases in microglia were shown to bind microfilaments, and stimulation with RANKL increased the proportion of V-ATPase associated with the detergent-insoluble cytoskeletal fraction and with actin. In summary, microglia express the a3-subunit of V-ATPase. The expression of a3 and the interaction between V-ATPases and microfilaments was modulated by RANKL. These data suggest a novel molecular pathway for regulating microglia.« less

Toxicology Studies of Lewisite and Sulfur Mustard Agents: Genetic Toxicity of Lewisite (L) in Chinese Hamster Ovary Cells

DTIC Science & Technology

1989-05-31

Density at 20°C: 1.888 g/ml State: Dark, oily liquid (stable in steel and glass ) Vapor pressure at 200C: 0.394 m Decomposition temperature: >1000C...Bradley, M.O., B. Bhuyan, M.C. Francis, R. Langenbach, A. Peterson and E. Huberman !981 Mutagenesis by chemical agents in V79 Chinese haaster ceill : a

Chromosome Aberrations in Normal and Ataxia-Telangiectasia Cells Exposed to Heavy Ions

NASA Technical Reports Server (NTRS)

Kawata, T.; Ito, H.; Liu, C.; Shigematsu, N.; George, K.; Cucinotta, F. A.

2007-01-01

Although cells derived from Ataxia Telangiectasia (AT) patients are known to exhibit abnormal responses to ionizing radiations, its underlying mechanism still remains unclear. Previously, the authors reported that at the same gamma-irradiation dose AT cells show higher frequencies of misrepair and deletions compared to normal human fibroblast cells. In this study, we investigated the effects of heavy ions beams on chromosomal aberrations in normal and AT cells. Normal and AT fibroblast cells arrested at G0/G1 phase were irradiated with 2 Gy of X-rays, 490 MeV/u Silicon (LET 55 keV/m), 500 MeV/u Iron (LET 185 keV/m) and 200 MeV/u Iron (LET 440 keV/m) particles, and then cells were allowed to repair for 24 hours at 37 degrees before subculture. Calyculin-A induced PCC method was employed to collect G2/M chromosomes and whole DNA probes 1 and 3 were used to analyze chromosomal aberrations such as color-junctions, deletions, simple exchanges (incomplete and reciprocal exanges) and complex-type exchanges. The percentages of aberrant cells were higher when normal and AT cells were exposed to heavy ions compared to X-rays, and had a tendency to increase with increasing LET up to 185 keV/m and then decreased at 440 keV/m. When the frequency of color-junctions per cell was compared after X-ray exposure, AT cells had around three times higher frequency of color-junctions (mis-rejoining) than normal cells. However, at 185 keV/m there was no difference in the frequency of color-junctions between two cell lines. It was also found that the frequency of simple exchanges per cell was almost constant in AT cells regardless LET levels, but it was LET dependent for normal cells. Interestingly, the frequency of simple exchanges was higher for AT cells when it was compared at 185 keV/m but AT cells had more complex-type exchanges at the same LET levels. Heavy ions are more efficient in inducing chromosome aberrations in normal and AT cells compared to X-rays, and the aberration types between normal and AT fibroblast appeared different probably due to difference in the ATM gene function.

Deoxycholic acid inhibits smooth muscle contraction via protein kinase C-dependent modulation of L-type Ca2+ channels in rat proximal colon.

PubMed

Hu, Liu-Dan; Yu, Bao-Ping; Yang, Bin

2012-10-01

The aim of this study was to investigate the effects of deoxycholic acid (DCA) on the contractions of rat proximal colonic smooth muscle (PCSM) in vitro. The contractile response of rat PCSM strips was tested using a polyphysio-graph. The whole cell patch-clamp technique was also used in rat colonic smooth muscle cells (SMCs) isolated by an enzymatic procedure to record the L-type calcium current (I(Ca-L)) prior to and following the application of various concentrations of DCA. The application of DCA (10(-6)-10(-4) M) decreased the amplitude of spontaneous contractions of the PCSM strips in a dose-dependent manner. The administration of DCA (10(-5) M) caused the relaxation of isolated smooth muscle strips pre-contracted by acetylcholine (Ach) or KCl (by 12.2±1.5 and 16.3±6.9%, respectively). The concentration-response curve of CaCl2 was shifted to the right. Pre-treatment of the strips with the protein kinase C (PKC) inhibitor chelerythrine (1 µM) significantly attenuated the effects of DCA on the strips pre-contracted by Ach. DCA reduced the peak I(Ca-L) by 6.02±0.87% at 10(-6) M, 15.02±1.73% at 10(-5) M and 47.14±3.79% at 10(-4) M. DCA shifted the current-voltage (I-V) curve of ICa-L upward, but the contour of the I-V curve was unchanged, and the peak current-induced voltage remained at 0 mV. Pre-treatment with chelerythrine (1 µM) blocked the actions of DCA on the I(Ca-L). Taken together, the actions of DCA on I(Ca-L) in rat colonic SMCs contributed to a negative inotropic effect. These actions appear to be mediated through protein kinase C. Furthermore, this study suggests another possible mechanism for the DCA-related modulation of gastrointestinal motility.

Modification of SR-PSOX functions by multi-point mutations of basic amino acid residues.

PubMed

Liu, Weiwei; Yin, Lan; Dai, Yalei

2013-02-01

SR-PSOX can function as a scavenger receptor, a chemokine and an adhesion molecule, and it could be an interesting player in the formation of atherosclerotic lesions. Our previous studies demonstrated that basic amino acid residues in the chemokine domain of SR-PSOX are critical for its functions. In this study the combinations of the key basic amino acids in the chemokine domain of SR-PSOX have been identified. Five combinations of basic amino acid residues that may form conformational motif for SR-PSOX functions were selected for multi-point mutants. The double mutants of K61AR62A, R76AK79A, R82AH85A, and treble mutants of R76AR78AK79A, R78AR82AH85A were successfully constructed by replacing the combinations of two or three basic amino acid residues with alanine. After successful expression of these mutants on the cells, the functional studies showed that the cells expressing R76AK79A and R82AH85A mutants significantly increased the activity of oxLDL uptake compared with that of wild-type SR-PSOX. Meanwhile, the cells expressing R76AK79A mutant also dramatically enhanced the phagocytotic activity of SR-PSOX. However, the cells expressing the construct of combination of R78A mutation in R76AK79A or R82AH85A could abolish these effects. More interestingly, the adhesive activities were remarkably down regulated in the cells expressing the multi-point mutants respectively. This study revealed that some conformational motifs of basic amino acid residues, especially R76 with K79 in SR-PSOX, may form a common functional motif for its critical functions. R78 in SR-PSOX has the potential action to stabilize the function of oxLDL uptake and bacterial phagocytosis. The results obtained may provide new insight for the development of drug target of atherosclerosis. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Connexins in Prostate Cancer Initiation and Progression

DTIC Science & Technology

2013-11-01

the Golgi Apparatus for Cargo Transport Prior to Complete Assembly. Mol.Biol.Cell, 17, 4105-4117. 79. Hunziker,W. and Geuze,H. (2011...tumor growth by inducing the assembly of other junctional and signaling complexes? Wild type connexins which form functional gap junctions and mutant...and influences the function of two other important proteins that have been shown to prevent the spread of cancer cells from prostate to distant organs

Patients with primary breast and primary female genital tract diffuse large B cell lymphoma have a high frequency of MYD88 and CD79B mutations.

PubMed

Cao, Xin-Xin; Li, Jian; Cai, Hao; Zhang, Wei; Duan, Ming-Hui; Zhou, Dao-Bin

2017-11-01

This study is to retrospectively evaluate the prevalence of MYD88 and CD79B mutations and the clinicopathologic characteristics of patients with primary diffuse large B cell lymphoma (DLBCL) of the female genital tract and breast. The characteristics, treatments, and outcomes of 19 patients diagnosed with primary DLBCL of the female genital tract and breast, who had formalin-fixed and paraffin-embedded tissues obtained from diagnostic samples diagnosed between January 2004 and June 2016, were analyzed retrospectively. Nineteen female patients (7 with primary breast and 12 with primary female genital tract DLBCL) were included in this retrospective study. Eleven patients (57.9%) carried a MYD88 mutation, including 10 with MYD8 L265P and 1 with the MYD88 L265S mutation. Seven patients (36.8%) harbored a CD79B mutation, which included two cases with CD79B Y196H, two cases with CD79B Y196N, one case with CD79B Y196D, one case with CD79B Y196F, and one case with CD79B Y196X. Four cases had both MYD88 and CD79B mutations. The clinicopathologic parameters, progression-free survival (PFS), and overall survival (OS) of the MYD88 mutation-carrying group were not significantly different from those of the MYD88 wild-type group except for higher LDH levels. Six patients received cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP), while 13 patients received rituximab plus CHOP, and 13 patients received central nervous system prophylaxis. The median OS and PFS were 73 and 56 months, respectively. Patients with primary breast and primary female genital tract DLBCL have a high frequency of MYD88 and CD79B mutations. The presence of these mutations does not affect survival but may offer additional therapeutic options.

2-(4′-CHLOROPHENYL)-1,4-BENZOQUINONE INCREASES THE FREQUENCY OF MICRONUCLEI AND SHORTENS TELOMERES

PubMed Central

Jacobus, J.A.; Flor, S.; Klingelhutz, A.; Robertson, L.W.; Ludewig, G.

2008-01-01

The toxicity of polychlorinated biphenyls (PCBs) has been attributed widely to receptor-mediated effects, buttressed by the popularity of the Toxic Equivalency Factor. We propose that a crucial toxic mechanism of lower-chlorinated PCBs is their enzymatic biotransformation to electrophiles, including quinoid metabolites, that bind intracellular sulfhydryl groups, such as those found in microtubulin and enzymes like telomerase. To test this hypothesis, we have examined micronuclei induction, cell cycle, and telomere shortening in cells in culture. Our findings show a large increase in micronuclei frequency and cell cycle perturbation in V79 cells, and a marked decrease in telomere length in HaCaT cells exposed to 2-(4′-chlorophenyl)-1,4-benzoquinone (PCB3pQ). PMID:18438462

Low-frequency noise reduction in vertical MOSFETs having tunable threshold voltage fabricated with 60 nm CMOS technology on 300 mm wafer process

NASA Astrophysics Data System (ADS)

Imamoto, Takuya; Ma, Yitao; Muraguchi, Masakazu; Endoh, Tetsuo

2015-04-01

In this paper, DC and low-frequency noise (LFN) characteristics have been investigated with actual measurement data in both n- and p-type vertical MOSFETs (V-MOSFETs) for the first time. The V-MOSFETs which was fabricated on 300 mm bulk silicon wafer process have realized excellent DC performance and a significant reduction of flicker (1/f) noise. The measurement results show that the fabricated V-MOSFETs with 60 nm silicon pillar and 100 nm gate length achieve excellent steep sub-threshold swing (69 mV/decade for n-type and 66 mV/decade for p-type), good on-current (281 µA/µm for n-type 149 µA/µm for p-type), low off-leakage current (28.1 pA/µm for n-type and 79.6 pA/µm for p-type), and excellent on-off ratio (1 × 107 for n-type and 2 × 106 for p-type). In addition, it is demonstrated that our fabricated V-MOSFETs can control the threshold voltage (Vth) by changing the channel doping condition, which is the useful and low-cost technique as it has been widely used in the conventional bulk planar MOSFET. This result indicates that V-MOSFETs can control Vth more finely and flexibly by the combined the use of the doping technique with other techniques such as work function engineering of metal-gate. Moreover, it is also shown that V-MOSFETs can suppress 1/f noise (L\\text{gate}WS\\text{Id}/I\\text{d}2 of 10-13-10-11 µm2/Hz for n-type and 10-12-10-10 µm2/Hz for p-type) to one or two order lower level than previously reported nanowire type MOSFET, FinFET, Tri-Gate, and planar MOSFETs. The results have also proved that both DC and 1/f noise performances are independent from the bias voltage which is applied to substrate or well layer. Therefore, it is verified that V-MOSFETs can eliminate the effects from substrate or well layer, which always adversely affects the circuit performances due to this serial connection.

The role of lin-22, a hairy/enhancer of split homolog, in patterning the peripheral nervous system of C. elegans.

PubMed

Wrischnik, L A; Kenyon, C J

1997-08-01

In C. elegans, six lateral epidermal stem cells, the seam cells V1-V6, are located in a row along the anterior-posterior (A/P) body axis. Anterior seam cells (V1-V4) undergo a fairly simple sequence of stem cell divisions and generate only epidermal cells. Posterior seam cells (V5 and V6) undergo a more complicated sequence of cell divisions that include additional rounds of stem cell proliferation and the production of neural as well as epidermal cells. In the wild type, activity of the gene lin-22 allows V1-V4 to generate their normal epidermal lineages rather than V5-like lineages. lin-22 activity is also required to prevent additional neurons from being produced by one branch of the V5 lineage. We find that the lin-22 gene exhibits homology to the Drosophila gene hairy, and that lin-22 activity represses neural development within the V5 lineage by blocking expression of the posterior-specific Hox gene mab-5 in specific cells. In addition, in order to prevent anterior V cells from generating V5-like lineages, wild-type lin-22 gene activity must inhibit (directly or indirectly) at least five downstream regulatory gene activities. In anterior body regions, lin-22(+) inhibits expression of the Hox gene mab-5. It also inhibits the activity of the achaete-scute homolog lin-32 and an unidentified gene that we postulate regulates stem cell division. Each of these three genes is required for the expression of a different piece of the ectopic V5-like lineages generated in lin-22 mutants. In addition, lin-22 activity prevents two other Hox genes, lin-39 and egl-5, from acquiring new activities within their normal domains of function along the A/P body axis. Some, but not all, of the patterning activities of lin-22 in C. elegans resemble those of hairy in Drosophila.

H3 K79 dimethylation marks developmental activation of the beta-globin gene but is reduced upon LCR-mediated high-level transcription.

PubMed

Sawado, Tomoyuki; Halow, Jessica; Im, Hogune; Ragoczy, Tobias; Bresnick, Emery H; Bender, M A; Groudine, Mark

2008-07-15

Genome-wide analyses of the relationship between H3 K79 dimethylation and transcription have revealed contradictory results. To clarify this relationship at a single locus, we analyzed expression and H3 K79 modification levels of wild-type (WT) and transcriptionally impaired beta-globin mutant genes during erythroid differentiation. Analysis of fractionated erythroid cells derived from WT/Delta locus control region (LCR) heterozygous mice reveals no significant H3 K79 dimethylation of the beta-globin gene on either allele prior to activation of transcription. Upon transcriptional activation, H3 K79 di-methylation is observed along both WT and DeltaLCR alleles, and both alleles are located in proximity to H3 K79 dimethylation nuclear foci. However, H3 K79 di-methylation is significantly increased along the DeltaLCR allele compared with the WT allele. In addition, analysis of a partial LCR deletion mutant reveals that H3 K79 dimethylation is inversely correlated with beta-globin gene expression levels. Thus, while our results support a link between H3 K79 dimethylation and gene expression, high levels of this mark are not essential for high level beta-globin gene transcription. We propose that H3 K79 dimethylation is destabilized on a highly transcribed template.

Electrophysiological properties of myocytes isolated from the mouse atrioventricular node: L-type ICa, IKr, If, and Na-Ca exchange

PubMed Central

Choisy, Stéphanie C; Cheng, Hongwei; Orchard, Clive H; James, Andrew F; Hancox, Jules C

2015-01-01

The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. This study investigated the electrophysiology of cells isolated from the AVN region of adult mouse hearts, and compared murine ionic current magnitude with that of cells from the more extensively studied rabbit AVN. Whole-cell patch-clamp recordings of ionic currents, and perforated-patch recordings of action potentials (APs), were made at 35–37°C. Hyperpolarizing voltage commands from −40 mV elicited a Ba2+-sensitive inward rectifier current that was small at diastolic potentials. Some cells (Type 1; 33.4 ± 2.2 pF; n = 19) lacked the pacemaker current, If, whilst others (Type 2; 34.2 ± 1.5 pF; n = 21) exhibited a clear If, which was larger than in rabbit AVN cells. On depolarization from −40 mV L-type Ca2+ current, ICa,L, was elicited with a half maximal activation voltage (V0.5) of −7.6 ± 1.2 mV (n = 24). ICa,L density was smaller than in rabbit AVN cells. Rapid delayed rectifier (IKr) tail currents sensitive to E-4031 (5 μmol/L) were observed on repolarization to −40 mV, with an activation V0.5 of −10.7 ± 4.7 mV (n = 8). The IKr magnitude was similar in mouse and rabbit AVN. Under Na-Ca exchange selective conditions, mouse AVN cells exhibited 5 mmol/L Ni-sensitive exchange current that was inwardly directed negative to the holding potential (−40 mV). Spontaneous APs (5.2 ± 0.5 sec−1; n = 6) exhibited an upstroke velocity of 37.7 ± 16.2 V/s and ceased following inhibition of sarcoplasmic reticulum Ca2+ release by 1 μmol/L ryanodine, implicating intracellular Ca2+ cycling in murine AVN cell electrogenesis. PMID:26607172

ent-Trachylobane diterpenoids from Xylopia langsdorffiana.

PubMed

Tavares, Josean Fechine; Queiroga, Karine F; Silva, Marianna Vieira B; Diniz, Margareth F F M; Filho, José M B; da-Cunha, Emidio V L; de Simone, Carlos Alberto; Júnior, João X de Araújo; Melo, Patrícia S; Haun, Marcela; da Silva, Marcelo Sobral

2006-06-01

Two new diterpenes of the ent-trachylobane type were isolated from the stems of Xylopia langsdorffiana, ent-7alpha-acetoxytrachyloban-18-oic acid (1) and ent-7alpha-hydroxytrachyloban-18-oic acid (2). The structures of these isolates were deduced by spectroscopic data interpretation. X-ray crystallography of 1 was used to confirm its structure. The cytotoxic activity of 1 against V79 fibroblasts and rat hepatocytes was investigated.

Pressure-induced phase transition in GaN nanocrystals

NASA Astrophysics Data System (ADS)

Cui, Q.; Pan, Y.; Zhang, W.; Wang, X.; Zhang, J.; Cui, T.; Xie, Y.; Liu, J.; Zou, G.

2002-11-01

High-pressure in situ energy-dispersive x-ray diffraction experiments on GaN nanocrystals with 50 nm diameter have been carried out using a synchrotron x-ray source and a diamond-anvil cell up to about 79 GPa at room temperature. A pressure-induced first-order structural phase transition from the wurtzite-type structure to the rock-salt-type structure starts at about 48.8 GPa. The rock-salt-type phase persists to the highest pressure in our experimental range.

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

PubMed Central

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

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

PubMed

Peterson, A R; Peterson, H

1982-03-01

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.

Cell Type-Specific Structural Organization of the Six Layers in Rat Barrel Cortex

PubMed Central

Narayanan, Rajeevan T.; Udvary, Daniel; Oberlaender, Marcel

2017-01-01

The cytoarchitectonic subdivision of the neocortex into six layers is often used to describe the organization of the cortical circuitry, sensory-evoked signal flow or cortical functions. However, each layer comprises neuronal cell types that have different genetic, functional and/or structural properties. Here, we reanalyze structural data from some of our recent work in the posterior-medial barrel-subfield of the vibrissal part of rat primary somatosensory cortex (vS1). We quantify the degree to which somata, dendrites and axons of the 10 major excitatory cell types of the cortex are distributed with respect to the cytoarchitectonic organization of vS1. We show that within each layer, somata of multiple cell types intermingle, but that each cell type displays dendrite and axon distributions that are aligned to specific cytoarchitectonic landmarks. The resultant quantification of the structural composition of each layer in terms of the cell type-specific number of somata, dendritic and axonal path lengths will aid future studies to bridge between layer- and cell type-specific analyses. PMID:29081739

Evaluation of the genotoxic and antigenotoxic potential of Baccharis dracunculifolia extract on V79 cells by the comet assay.

PubMed

Munari, Carla Carolina; Alves, Jacqueline Morais; Bastos, Jairo Kenupp; Tavares, Denise Crispim

2010-01-01

Baccharis dracunculifolia (Asteraceae), the main botanical source of green propolis, is a shrub of the Brazilian 'cerrado'. In folk medicine it is used as an anti-inflammatory agent, mainly for the treatment of gastrointestinal diseases. The aim of the present study was to evaluate the genotoxic and antigenotoxic effects of B. dracunculifolia ethyl acetate extract (Bd-EAE) on Chinese hamster lung fibroblasts (V79 cells) by the comet assay. Methyl methanesulfonate (MMS; 200 microM) was used as an inducer of DNA damage. Genotoxicity was evaluated using four different concentrations of Bd-EAE: 12.5, 25.0, 50.0 and 100.0 microg ml(-1). Antigenotoxicity was assessed before, simultaneously, and after treatment with the mutagen. The results showed a significant increase in the frequency of DNA damage in cultures treated with 50.0 and 100.0 microg ml(-1) Bd-EAE. Regarding its antigenotoxic potential, Bd-EAE reduced the frequency of DNA damage induced by MMS. However, this chemopreventive activity depended on the concentrations and treatment regimens used. The antioxidant activity of phenolic components present in Bd-EAE may contribute to reduce the alkylation damage induced by MMS. In conclusion, our findings confirmed the chemopreventive activity of Bd-EAE and showed that this effect occurs under different mechanism.

Alkylarylnitrosoureas--stability in aqueous solution, partition coefficient, alkylating activity and its relationship to SCE induction in Chinese hamster V 79-E cells.

PubMed

Mendel, J; Thust, R; Schwarz, H

1982-01-01

The alkylating activity, chemical stability in aqueous solution (pH 7.0; 37 degrees C), and partition coefficient (octanol/water) of the following compounds were determined: 1-methyl-3-phenyl-1-nitrosourea (MPNU), 1-ethyl-3-phenyl-1-nitrosourea (EPNU), 1-isopropyl-3-phenyl-1-nitrosourea (i-PrPNU), 1-methyl-3-(p-fluorophenyl)-1-nitrosourea (F-MPNU), 1-methyl-3-(p-chlorophenyl)-1-nitrosourea (Cl-MPNU), 1-methyl-3-(p-bromophenyl)-1-nitrosourea (Br-MPNU), 1,3-dimethyl-3-phenyl-1-nitrosourea (DMPNU), and 1-methyl-3-naphthyl-1-nitrosocarbamate (NCA). 1-Methyl-1-nitrosourea (MNU) and 1-ethyl-1-nitrosourea (ENU) were used for the comparison. THe rate of decomposition in aqueous solution is discussed concerning the influences of the substituents at the 1- and 3-N-atom. The mono- and disubstituted N-nitrosoureas showed a coarse correlation between alkylating activity and SCE induction in Chinese hamster V 79-E cells. On the other hand, this correlation is missing in the case of NCA, which is a potent SCE inducer despite relatively low alkylating activity. DMPNU is the strongest SCE inducer, but this compound shows a high stability in aqueous solution and, consequently, we were not able to detect an alkylating activity.

Myogenic tone is impaired at low arterial pressure in mice deficient in the low-voltage-activated CaV 3.1 T-type Ca(2+) channel.

PubMed

Björling, K; Morita, H; Olsen, M F; Prodan, A; Hansen, P B; Lory, P; Holstein-Rathlou, N-H; Jensen, L J

2013-04-01

Using mice deficient in the CaV 3.1 T-type Ca(2+) channel, the aim of the present study was to elucidate the molecular identity of non-L-type channels involved in vascular tone regulation in mesenteric arteries and arterioles. We used immunofluorescence microscopy to localize CaV 3.1 channels, patch clamp electrophysiology to test the effects of a putative T-type channel blocker NNC 55-0396 on whole-cell Ca(2+) currents, pressure myography and Ca(2+) imaging to test diameter and Ca(2+) responses of the applied vasoconstrictors, and Q-PCR to check mRNA expression levels of several Ca(2+) handling proteins in wild-type and CaV 3.1(-/-) mice. Our data indicated that CaV 3.1 channels are important for the maintenance of myogenic tone at low pressures (40-80 mm Hg), whereas they are not involved in high-voltage-activated Ca(2+) currents, Ca(2+) entry or vasoconstriction to high KCl in mesenteric arteries and arterioles. Furthermore, we show that NNC 55-0396 is not a specific T-type channel inhibitor, as it potently blocks L-type and non-L-type high-voltage-activated Ca(2+) currents in mouse mesenteric vascular smooth muscle cell. Our data using mice deficient in the CaV 3.1 T-type channel represent new evidence for the involvement of non-L-type channels in arteriolar tone regulation. We showed that CaV 3.1 channels are important for the myogenic tone at low arterial pressure, which is potentially relevant under resting conditions in vivo. Moreover, CaV 3.1 channels are not involved in Ca(2+) entry and vasoconstriction to large depolarization with, for example, high KCl. Finally, we caution against using NNC 55-0396 as a specific T-type channel blocker in native cells expressing high-voltage-activated Ca(2+) channels. Acta Physiologica © 2013 Scandinavian Physiological Society.

Susceptibility of Primary Human Choroid Plexus Epithelial Cells and Meningeal Cells to Infection by JC Virus.

PubMed

O'Hara, Bethany A; Gee, Gretchen V; Atwood, Walter J; Haley, Sheila A

2018-04-15

JC polyomavirus (JCPyV) establishes a lifelong persistence in roughly half the human population worldwide. The cells and tissues that harbor persistent virus in vivo are not known, but renal tubules and other urogenital epithelial cells are likely candidates as virus is shed in the urine of healthy individuals. In an immunosuppressed host, JCPyV can become reactivated and cause progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system. Recent observations indicate that JCPyV may productively interact with cells in the choroid plexus and leptomeninges. To further study JCPyV infection in these cells, primary human choroid plexus epithelial cells and meningeal cells were challenged with virus, and their susceptibility to infection was compared to the human glial cell line, SVG-A. We found that JCPyV productively infects both choroid plexus epithelial cells and meningeal cells in vitro Competition with the soluble receptor fragment LSTc reduced virus infection in these cells. Treatment of cells with neuraminidase also inhibited both viral infection and binding. Treatment with the serotonin receptor antagonist, ritanserin, reduced infection in SVG-A and meningeal cells. We also compared the ability of wild-type and sialic acid-binding mutant pseudoviruses to transduce these cells. Wild-type pseudovirus readily transduced all three cell types, but pseudoviruses harboring mutations in the sialic acid-binding pocket of the virus failed to transduce the cells. These data establish a novel role for choroid plexus and meninges in harboring virus that likely contributes not only to meningoencephalopathies but also to PML. IMPORTANCE JCPyV infects greater than half the human population worldwide and causes central nervous system disease in patients with weakened immune systems. Several recent reports have found JCPyV in the choroid plexus and leptomeninges of patients with encephalitis. Due to their role in forming the blood-cerebrospinal fluid barrier, the choroid plexus and leptomeninges are also poised to play roles in virus invasion of brain parenchyma, where infection of macroglial cells leads to the development of progressive multifocal leukoencephalopathy, a severely debilitating and often fatal infection. In this paper we show for the first time that primary choroid plexus epithelial cells and meningeal cells are infected by JCPyV, lending support to the association of JCPyV with meningoencephalopathies. These data also suggest that JCPyV could use these cells as reservoirs for the subsequent invasion of brain parenchyma. Copyright © 2018 American Society for Microbiology.

Critical Role for Interferon Regulatory Factor 3 (IRF-3) and IRF-7 in Type I Interferon-Mediated Control of Murine Norovirus Replication

PubMed Central

Thackray, Larissa B.; Duan, Erning; Lazear, Helen M.; Kambal, Amal; Schreiber, Robert D.; Diamond, Michael S.

2012-01-01

Human noroviruses (HuNoV) are the major cause of epidemic, nonbacterial gastroenteritis in the world. The short course of HuNoV-induced symptoms has implicated innate immunity in control of norovirus (NoV) infection. Studies using murine norovirus (MNV) confirm the importance of innate immune responses during NoV infection. Type I alpha and beta interferons (IFN-α/β) limit HuNoV replicon function, restrict MNV replication in cultured cells, and control MNV replication in vivo. Therefore, the cell types and transcription factors involved in antiviral immune responses and IFN-α/β-mediated control of NoV infection are important to define. We used mice with floxed alleles of the IFNAR1 chain of the IFN-α/β receptor to identify cells expressing lysozyme M or CD11c as cells that respond to IFN-α/β to restrict MNV replication in vivo. Furthermore, we show that the transcription factors IRF-3 and IRF-7 work in concert to initiate unique and overlapping antiviral responses to restrict MNV replication in vivo. IRF-3 and IRF-7 restrict MNV replication in both cultured macrophages and dendritic cells, are required for induction of IFN-α/β in macrophages but not dendritic cells, and are dispensable for the antiviral effects of IFN-α/β that block MNV replication. These studies suggest that expression of the IFN-α/β receptor on macrophages/neutrophils and dendritic cells, as well as of IRF-3 and IRF-7, is critical for innate immune responses to NoV infection. PMID:23035219

Differential distribution of voltage-gated channels in myelinated and unmyelinated baroreceptor afferents.

PubMed

Schild, John H; Kunze, Diana L

2012-12-24

Voltage gated ion channels (VGC) make possible the frequency coding of arterial pressure and the neurotransmission of this information along myelinated and unmyelinated fiber pathways. Although many of the same VGC isoforms are expressed in both fiber types, it is the relative expression of each that defines the unique discharge properties of myelinated A-type and unmyelinated C-type baroreceptors. For example, the fast inward Na⁺ current is a major determinant of the action potential threshold and the regenerative transmembrane current needed to sustain repetitive discharge. In A-type baroreceptors the TTX-sensitive Na(v)1.7 VGC contributes to the whole cell Na⁺ current. Na(v)1.7 is expressed at a lower density in C-type neurons and in conjunction with TTX-insensitive Na(v)1.8 and Na(v)1.9 VGC. As a result, action potentials of A-type neurons have firing thresholds that are 15-20 mV more negative and upstroke velocities that are 5-10 times faster than unmyelinated C-type neurons. A more depolarized threshold in conjunction with a broader complement of non-inactivating K(V) VGC subtypes produces C-type action potentials that are 3-4 times longer in duration than A-type neurons and at markedly lower levels of cell excitability. Unmyelinated baroreceptors also express KCa1.1 which provides approximately 25% of the total outward K⁺ current. KCa1.1 plays a critically important role in shaping the action potential profile of C-type neurons and strongly impacts neuronal excitability. A-type neurons do not functionally express the KCa1.1 channel despite having a whole cell Ca(V) current quite similar to that of C-type neurons. As a result, A-type neurons do not have the frequency-dependent braking forces of KCa1.1. Lack of a KCa current and only a limited complement of non-inactivating K(V) VGC in addition to a hyperpolarization activated HCN1 current that is nearly 10 times larger than in C-type neurons leads to elevated levels of discharge in A-type neurons, a hallmark of myelinated baroreceptors. Interestingly, HCN2 and HCN4 expression levels are comparable in both fiber types. Collectively, such apportion of VGC constrains the neural coding of myelinated A-type baroreceptors to low threshold, high frequency, high fidelity discharge but with a limited capacity for neuromodulation of afferent bandwidth. Unmyelinated C-type baroreceptors require greater depolarizing forces for spike initiation and have a low frequency discharge profile that is often poorly correlated with the physiological stimulus. But the complement of VGC in C-type neurons provides far greater capacity for neuromodulation of cell excitability than can be obtained from A-type baroreceptors. Copyright © 2012 Elsevier B.V. All rights reserved.

Existence of c-Kit negative cells with ultrastructural features of interstitial cells of Cajal in the subserosal layer of the W/W(v) mutant mouse colon.

PubMed

Tamada, Hiromi; Kiyama, Hiroshi

2015-01-01

Interstitial cells of Cajal (ICC) are mesenchymal cells that are distributed along the gastrointestinal tract and function as pacemaker cells or intermediary cells between nerves and smooth muscle cells. ICC express a receptor tyrosine kinase c-Kit, which is an established marker for ICC. The c-kit gene is allelic with the murine white-spotting locus (W), and some ICC subsets were reported to be missing in heterozygous mutant W/W(v) mice carrying W and W(v) mutated alleles. In this study, the characterization of interstitial cells in the subserosal layer of W/W(v) mice was analyzed by immunohistochemistry and electron microscopy. In the proximal and distal colon of W/W(v) mutant mice, no c-Kit-positive cells were detected in the subserosal layer by immunohistochemistry. By electron microscopy, the interstitial cells, which were characterized by the existence of caveolae, abundant mitochondria and gap junctions, were observed in the W/W(v) mutant colon. The morphological characteristics were comparable to those of the multipolar c-Kit positive ICC seen in the subserosa of proximal and distal colon of wild-type mice. Fibroblasts were also located in the same layers, but the morphology of the fibroblasts was distinguishable from that of ICC in wild type mice or of ICC-like cells in W/W(v) mutant mice. Collectively, it is concluded that c-Kit-negative interstitial cells showing a typical ICC ultrastructure exist in the proximal and distal colon of W/W(v) mutant mice.

Solar energy conversion and storage by using Rose Extract as natural dye and nitrilotriacetic acid as reductant in photogalvanic cell

NASA Astrophysics Data System (ADS)

Yadav, Sushil Kumar

2018-05-01

Photogalvanic effect was studied in Photogalvanic cell containing Rose Extract was used as Natural Dye (Photosensitizer), Nitrilotriacetic acid (NTA) as Reductant. The observed value of photopotential and photocurrent generated by this cell were 872 mV and 176 µA, respectively. The observed power at power point was 82.18 µW and the conversion efficiency was 0.79 %. The fill factor 0.4678 was experimentally determined at the power point of the cell. The photogalvanic cell can be used in dark for 42 min., showing the storage capacity of the cell against charging time was 200 min. The effect of different parameters on electrical output of the cell was observed and a mechanism has also been proposed for the generation of photocurrent in photogalvanic cell.

Looking For a Needle in the Haystack: Deciphering Indigenous 1.79 km Deep Subsurface Microbial Communities from Drilling Mud Contaminants Using 454 Pyrotag Sequencing

NASA Astrophysics Data System (ADS)

Dong, Y.; Cann, I.; Mackie, R.; Price, N.; Flynn, T. M.; Sanford, R.; Miller, P.; Chia, N.; Kumar, C. G.; Kim, P.; Sivaguru, M.; Fouke, B. W.

2010-12-01

Knowledge of the composition, structure and activity of microbial communities that live in deeply buried sedimentary rocks is fundamental to the future of subsurface biosphere stewardship as it relates to hydrocarbon exploration and extraction, carbon sequestration, gas storage and groundwater management. However, the study of indigenous subsurface microorganisms has been limited by the technical challenges of collecting deep formation water samples that have not been heavily contaminated by the mud used to drill the wells. To address this issue, a “clean-sampling method” deploying the newly developed Schlumberger Quicksilver MDT probe was used to collect a subsurface sample at a depth of 1.79 km (5872 ft) from an exploratory well within Cambrian-age sandstones in the Illinois Basin. This yielded a formation water sample that was determined to have less than 4% drilling mud contamination based on tracking changes in the aqueous geochemistry of the formation water during ~3 hours of pumping at depth prior to sample collection. A suite of microscopy and culture-independent molecular analyses were completed using the DNA extracted from microbial cells in the formation water, which included 454 amplicon pyrosequencing that targeted the V1-V3 hypervariable region of bacterial 16S rRNA gene sequences. Results demonstrated an extremely low diversity microbial community living in formation water at 1.79 km-depth. More than 95 % of the total V1-V3 pyrosequencing reads (n=11574) obtained from the formation water were affiliated with a halophilic γ-proteobacterium and most closely related to the genus Halomonas. In contrast, about 3 % of the V1-V3 sequences in the drilling mud library (n=13044) were classified as genus Halomonas but were distinctly different and distantly related to the formation water Halomonas detected at 1.79 km-depth. These results were consistent with those obtained using a suite of other molecular screens (e.g., Terminal-Restriction Fragment Length Polymorphism (T-RFLP) and the initial full length 16S rRNA amplicon libraries) and bioinformatic analyses (e.g., 16S rRNA and Open Reading Frame (ORF) calls established from the 454 metagenomic community analyses). Functional pathway modeling is underway to evaluate the adaptation of this indigenous microbial community to the hydrologic and geologic history of the deep subsurface environment of the Illinois Basin.

Dose--response of initial G2-chromatid breaks induced in normal human fibroblasts by heavy ions

NASA Technical Reports Server (NTRS)

Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Takai, N.; Wu, H.; Cucinotta, F. A.; Dicello, J. F. (Principal Investigator)

2001-01-01

PURPOSE: To investigate initial chromatid breaks in prematurely condensed G2 chromosomes following exposure to heavy ions of different LET. MATERIAL AND METHODS: Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (13 keV/ microm, 80 keV/microm), silicon (55 keV/microm) and iron (140 keV/microm, 185keV/microm, 440keV/microm) ions. Chromosomes were prematurely condensed using calyculin-A. Initial chromatid-type and isochromatid breaks in G2 cells were scored. RESULTS: The dose response curves for total chromatid breaks were linear regardless of radiation type. The relative biological effectiveness (RBE) showed a LET-dependent increase, peaking around 2.7 at 55-80keV/microm and decreasing at higher LET. The dose response curves for isochromatid-type breaks were linear for high-LET radiations, but linear-quadratic for gamma-rays and 13 keV/microm carbon ions. The RBE for the induction of isochromatid breaks obtained from linear components increased rapidly between 13keV/microm (about 7) and 80keV/microm carbon (about 71), and decreased gradually until 440 keV/microm iron ions (about 66). CONCLUSIONS: High-LET radiations are more effective at inducing isochromatid breaks, while low-LET radiations are more effective at inducing chromatid-type breaks. The densely ionizing track structures of heavy ions and the proximity of sister chromatids in G2 cells result in an increase in isochromatid breaks.

46 CFR 111.79-13 - Different voltages and power types.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Different voltages and power types. 111.79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power types. If...

46 CFR 111.79-13 - Different voltages and power types.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Different voltages and power types. 111.79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power types. If...

46 CFR 111.79-13 - Different voltages and power types.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Different voltages and power types. 111.79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power types. If...

46 CFR 111.79-13 - Different voltages and power types.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Different voltages and power types. 111.79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power types. If...

46 CFR 111.79-13 - Different voltages and power types.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Different voltages and power types. 111.79-13 Section 111.79-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-13 Different voltages and power types. If...

Sequence typing of human adenoviruses isolated from Polish patients subjected to allogeneic hematopoietic stem cell transplantation - a single center experience.

PubMed

Przybylski, Maciej; Rynans, Sylwia; Waszczuk-Gajda, Anna; Bilinski, Jarosław; Basak, Grzegorz W; Jędrzejczak, Wiesław W; Wróblewska, Marta; Młynarczyk, Grażyna; Dzieciątkowski, Tomasz

2018-03-28

Human adenoviruses (HAdV) from species A, B and C are commonly recognized as pathogens causing severe morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. The purpose of the present study was to determine HAdV types responsible for viremia in HSCT recipients at a large tertiary hospital in Poland. Analysis of partial nucleotide sequences of HAdV hexon gene was used to type 40 clinical isolates of HAdV obtained from 40 HSCT recipients. We identified six different HAdV serotypes belonging to species B, C and E. We demonstrated high variability in sequences of detected HAdV types, and patients infected with the same HAdV types were not hospitalized at the same time, which suggests the low possibility of cross-infection. In almost all patients, anti-HAdV antibodies in IgG class were detected, which indicates a history of HAdV infection in the past. Clinical symptoms accompanying HAdV viremia were in 89%, and in 61.5% of individuals, HAdV was a sole pathogen detected. There were no cases with high-level HAdV viremia and severe systemic or organ infections. Graft-versus-host disease (GvHD) was present in patients infected with species B and C, but grade II of GvHD was observed only in patients infected with HAdV-B. The predominance of HAdV-C and common presence of anti-HAdV antibodies in IgG class may strongly suggest that most infections in the present study were reactivations of HAdV persisting into the patient's mucosa-associated lymphoid tissues. Variability of HAdV sequences suggests that cross-infections between patients were very rare. GvHD: graft-versus-host disease; HAdV: human adenoviruses; HSCT: hematopoietic stem cell transplantation.

Genotoxic and biochemical changes in Baccharis trimera induced by coal contamination.

PubMed

Menezes, A P S; Da Silva, J; Rossato, R R; Santos, M S; Decker, N; Da Silva, F R; Cruz, C; Dihl, R R; Lehmann, M; Ferraz, A B F

2015-04-01

The processing and combustion of coal in thermal power plants release anthropogenic chemicals into the environment. Baccharis trimera is a common plant used in folk medicine that grows readily in soils degraded by coal mining activities. This shrub bioaccumulates metals released into the environment, and thus its consumption may be harmful to health. The purpose of this study was to investigate the phytochemical profile, antioxidant capacity (DPPH), genotoxic (comet assay) and mutagenic potential (CBMN-cyt) in V79 cells of B. trimera aqueous extracts in the coal-mining region of Candiota (Bt-AEC), and in Bagé, a city that does not experience the effects of exposure to coal (Bt-AEB, a reference site). In the comet assay, only Bt-AEC was genotoxic at the highest doses (0.8mg/mL and 1.6mg/mL), compared to the control. For extracts from both areas, mutagenic effects were observed at higher concentrations compared to the control. The cell damage parameters were significantly high in both extracts; however, more striking values were observed for Bt-AEC, up to the dose of 0.8mg/mL. In chemical analysis, no variation was observed in the contents of flavonoids and phenolic compounds, neither the antioxidant activity, which may suggest that DNA damage observed in V79 cells was induced by the presence of coal contaminants absorbed by the plant. Copyright © 2015 Elsevier Inc. All rights reserved.

Building mechanism for a high open-circuit voltage in an all-solution-processed tandem polymer solar cell.

PubMed

Kong, Jaemin; Lee, Jongjin; Kim, Geunjin; Kang, Hongkyu; Choi, Youna; Lee, Kwanghee

2012-08-14

Additional post-processing techniques, such as post-thermal annealing and UV illumination, were found to be required to obtain desirable values of the cell parameters in a tandem polymer solar cell incorporated with solution-processed basic n-type titanium sub-oxide (TiO(x))/acidic p-type poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) interlayers. Subsequent to the fabrication of the tandem polymer solar cells, the open-circuit voltage (V(OC)) of the cells exhibited half of the expected value. Only after the application of the post-treatments, the V(OC) of a tandem cell increased from the initial half-cell value (∼0.6 V) to its full-cell value (∼1.2 V). The selective light-biased incident photon-to-current efficiency (IPCE) measurements indicated that the initial V(OC) originated from the back subcell and that the application of the post-processing treatments revived the front subcell, such that the net photocurrent of the tandem cell was finally governed by a recombination process of holes from the back subcell and electrons from the front subcell. Based on our experimental results, we suggest that a V(OC) enhancement could be ascribed to two types of subsequent junction formations at the interface between the TiO(x) and PEDOT:PSS interlayers: an 'ion-mediated dipole junction', resulting from the electro-kinetic migration of cationic ions in the interlayers during post-thermal annealing in the presence of a low-work-function metal cathode, and a 'photoinduced Schottky junction', formed by increasing the charge carrier density in the n-type TiO(x) interlayer during UV illumination process. The two junctions separately contributed to the formation of a recombination junction through which the electrons in TiO(x) and the holes in PEDOT:PSS were able to recombine without substantial voltage drops.

Cytotoxic, mutagenicity, and genotoxicity effects of guanylhydrazone derivatives.

PubMed

Pinhatti, Valéria Rodrigues; da Silva, Juliana; Martins, Tales Leandro Costa; Moura, Dinara Jaqueline; Rosa, Renato Moreira; Villela, Izabel; Stopiglia, Cheila Denise Ottonelli; da Silva Santos, Selma; Scroferneker, Maria Lúcia; Machado, Carlos Renato; Saffi, Jenifer; Henriques, João Antonio Pêgas

2016-08-01

Several studies have reported that guanylhydrazones display a variety of desirable biological properties, such as antihypertensive, antibacterial, and antimalarial behaviour. They furthermore promote anti-pneumocystosis and anti-trypanosomiasis, exhibit antitumor activity, and show significant cytotoxicity against cancer cell lines. In this work, we have evaluated the cytotoxicity, mutagenicity, and genotoxicity of two guanylhydrazones derivatives, (E)-2-[(2,3-dimethoxyphenyl) methylene] hydrazine carboxymidamide hydrochloride (2,3-DMeB) and (E)-2-[(3,4-dimethoxyphenyl) methylene] hydrazine carboxymidamide hydrochloride (3,4-DMeB), in different biological models. Both 2,3-DMeB and 3,4-DMeB induce weak cytotoxic and mutagenic effects in bacteria and yeast. The genotoxicity of these compounds was determined in a fibroblast cell line (V79) using alkaline comet assay, as well as a modified comet assay with bacterial enzymes formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (EndoIII). Both guanylhydrazone derivatives induced DNA damage. Treatment of V79 cells with EndoIII and FPG proteins demonstrated a significant effect of 2,3-DMeB and 3,4-DMeB with respect to oxidized bases. In addition, the derivatives induced a significant increase in the frequency of micronucleated cells at high doses. The antifungal and anti-trypanosomal properties of these guanylhydrazone derivatives were also evaluated, and the obtained results suggest that 2,3-DMeB is more effective than 3,4-DMeB. The biological activity of 2,3-DMeB and 3,4-DMeB may thus be related, at least in part, to their oxidative potential, as well as to their ability to interact with DNA. Considering the previously reported in vitro antitumor activity of guanylhydrazone derivatives in combination with the lack of acute toxicity and the fact that DNA damage is only observed at high doses should render both compounds good candidates for in vivo studies on antitumor activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Room-temperature preparation of trisilver-copper-sulfide/polymer based heterojunction thin film for solar cell application

NASA Astrophysics Data System (ADS)

Lei, Yan; Yang, Xiaogang; Gu, Longyan; Jia, Huimin; Ge, Suxiang; Xiao, Pin; Fan, Xiaoli; Zheng, Zhi

2015-04-01

Solar cells devices based on inorganic/polymer heterojunction can be a possible solution to harvest solar energy and convert to electric energy with high efficiency through a cost-effective fabrication. The solution-process method can be easily used to produce large area devices. Moreover, due to the intrinsic different charge separation, diffusion or recombination in various semiconductors, the interfaces between each component may strongly influence the inorganic/polymer heterojunction performance. Here we prepared a n-type Ag3CuS2 (Eg = 1.25 eV) nanostructured film through a room-temperature element reaction process, which was confirmed as direct bandgap semiconductor through density function theory simulation. This Ag3CuS2 film was spin-coated with an organic semiconducting poly(3-hexythiophene) (P3HT) or polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) film, which formed an inorganic/polymer heterojunction. After constructing it to a solar cell device, the power conversion efficiencies of 0.79% and 0.31% were achieved with simulated solar illumination on Ag3CuS2/P3HT and Ag3CuS2/PTB7, respectively. A possible mechanism was discussed and we showed the charge separation at interface of inorganic and polymer semiconductors played an important role.

Vorinostat and Azacitidine in Treating Patients With Locally Recurrent or Metastatic Nasopharyngeal Cancer or Nasal Natural Killer T-Cell Lymphoma

ClinicalTrials.gov

2018-04-20

Adult Nasal Type Extranodal NK/T-Cell Lymphoma; Recurrent Nasopharyngeal Keratinizing Squamous Cell Carcinoma; Recurrent Nasopharyngeal Undifferentiated Carcinoma; Stage IV Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage IV Nasopharyngeal Undifferentiated Carcinoma AJCC v7

Parvularcula flava sp. nov., an alphaproteobacterium isolated from surface seawater of the South China Sea.

PubMed

Zhang, Xin-Qi; Wu, Yue-Hong; Zhou, Xiang; Zhang, Xin; Xu, Xue-Wei; Wu, Min

2016-09-01

An aerobic, coccoid to short rod, yellow-pigmented, non-sporulating and Gram-staining-negative bacterium, designated NH6-79T, was isolated from surface seawater of the South China Sea. The isolate was motile with a polar flagellum. Growth was observed at 4-42 °C (optimum 37 °C), at pH 6.0-8.5 (optimum pH 7.0), and with 0.5-11 % (w/v) NaCl (optimum 4.5 %) and 1.5-17 % (w/v) sea salt (optimum 3.5-5 %). Strain NH6-79T could decompose peptone to produce H2S, but could not hydrolyse skimmed milk. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NH6-79T had the closest affinity to the genus Parvularcula, sharing the highest 16S rRNA gene sequence similarity with 'Parvularcula oceanus' JLT2013 (94.1 %), Parvularcula lutaonensis CC-MMS-1T (93.4 %), Parvularcula dongshanensis SH25T (92.9 %) and Parvularcula bermudensis HTCC2503T (92.7 %), and lower sequence similarities (<90 %) with all other genera. The dominant fatty acids were C18 : 1ω7c and C16 : 0. The polar lipid profile was mainly composed of three unidentified glycolipids. The predominant isoprenoid quinone was ubiquinone-10. The DNA G+C content was 60.7 mol%. Based on the polyphasic taxonomic characterization, strain NH6-79T is considered to represent a novel species of the genus Parvularcula, for which the name Parvularcula flava sp. nov. is proposed. The type strain is NH6-79T (=CGMCC 1.14984T=JCM 30557T=MCCC 1K00277T).

Pattern of endothelial progenitor cells and apoptotic endothelial cell-derived microparticles in chronic heart failure patients with preserved and reduced left ventricular ejection fraction.

PubMed

Berezin, Alexander E; Kremzer, Alexander A; Martovitskaya, Yulia V; Berezina, Tatyana A; Gromenko, Elena A

2016-02-01

Chronic heart failure (HF) remains a leading cause of cardiovascular (CV) mortality and morbidity worldwide. The aim of the study was to investigate whether the pattern of angiogenic endothelial progenitor cells (EPCs) and apoptotic endothelial cell-derived microparticles (EMPs) would be able to differentiate HF with reduced (HFrEF) and preserved (HFpEF) ejection fraction. One hundred sixty four chronic HF subjects met inclusion criteria. Patients with global left ventricular ejection fraction ≥ 50% were categorized as the HFpEF group (n = 79) and those with ≤ 45% as the HFrEF group (n = 85). Therefore, to compare the circulating levels of biological markers 35 control subjects without HF were included in the study. All control individuals were age- and sex-matched chronic HF patients. The serum level of biomarkers was measured at baseline. The flow cytometric technique was used for predictably distinguishing circulating cell subsets depending on expression of CD45, CD34, CD14, Tie-2, and CD309 antigens and determining endothelial cell-derived microparticles. CD31(+)/annexin V(+) was defined as apoptotic endothelial cell-derived MPs, MPs labeled for CD105(+) or CD62E(+) were determined as MPs produced due to activation of endothelial cells. In multivariate logistic regression model T2DM (R(2) = 0.26; P = 0.001), obesity (R(2) = 0.22; P = 0.001), previous MI (R(2) = 0.17; P = 0.012), galectin-3 (R(2) = 0.67; P = 0.012), CD31(+)/annexin V(+) EMPs (R(2) = 0.11; P = 0.001), NT-proBNP (R(2) = 0.11; P = 0.046), CD14(+) CD309(+) cells (R(2) = 0.058; P = 0.001), and CD14(+) СD309(+) Tie-2(+) cells (R(2) = 0.044; P = 0.028) were found as independent predictors of HFpEF. Using multivariate Cox-regression analysis adjusted etiology (previous myocardial infarction), cardiovascular risk factors (obesity, type 2 diabetes mellitus) we found that NT-proBNP (OR 1.08; 95% CI = 1.03-1.12; P = 0.001) and CD31(+)/annexin V(+) EMPs to CD14(+) CD309(+) cell ratio (OR 1.06; 95% CI = 1.02-1.11; P = 0.02) were independent predictors for HFpEF. We found that CD31(+)/annexin V(+) EMPs to CD14(+) CD309(+) cell ratio added to NT-proBNP, clinical data, and cardiovascular risk factors has exhibited the best discriminate value and higher reliability to predict HFpEF compared with NT-proBNP and clinical data/cardiovascular risk factors alone.

Regulation of L-type CaV1.3 channel activity and insulin secretion by the cGMP-PKG signaling pathway.

PubMed

Sandoval, Alejandro; Duran, Paz; Gandini, María A; Andrade, Arturo; Almanza, Angélica; Kaja, Simon; Felix, Ricardo

2017-09-01

cGMP is a second messenger widely used in the nervous system and other tissues. One of the major effectors for cGMP is the serine/threonine protein kinase, cGMP-dependent protein kinase (PKG), which catalyzes the phosphorylation of a variety of proteins including ion channels. Previously, it has been shown that the cGMP-PKG signaling pathway inhibits Ca 2+ currents in rat vestibular hair cells and chromaffin cells. This current allegedly flow through voltage-gated Ca V 1.3L-type Ca 2+ channels, and is important for controlling vestibular hair cell sensory function and catecholamine secretion, respectively. Here, we show that native L-type channels in the insulin-secreting RIN-m5F cell line, and recombinant Ca V 1.3 channels heterologously expressed in HEK-293 cells, are regulatory targets of the cGMP-PKG signaling cascade. Our results indicate that the Ca V α 1 ion-conducting subunit of the Ca V 1.3 channels is highly expressed in RIN-m5F cells and that the application of 8-Br-cGMP, a membrane-permeable analogue of cGMP, significantly inhibits Ca 2+ macroscopic currents and impair insulin release stimulated with high K + . In addition, KT-5823, a specific inhibitor of PKG, prevents the current inhibition generated by 8-Br-cGMP in the heterologous expression system. Interestingly, mutating the putative phosphorylation sites to residues resistant to phosphorylation showed that the relevant PKG sites for Ca V 1.3 L-type channel regulation centers on two amino acid residues, Ser793 and Ser860, located in the intracellular loop connecting the II and III repeats of the Ca V α 1 pore-forming subunit of the channel. These findings unveil a novel mechanism for how the cGMP-PKG signaling pathway may regulate Ca V 1.3 channels and contribute to regulate insulin secretion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Calcium current in type I hair cells isolated from the semicircular canal crista ampullaris of the rat.

PubMed

Almanza, Angélica; Vega, Rosario; Soto, Enrique

2003-12-24

The low voltage gain in type I hair cells implies that neurotransmitter release at their afferent synapse should be mediated by low voltage activated calcium channels, or that some peculiar mechanism should be operating in this synapse. With the patch clamp technique, we studied the characteristics of the Ca(2+) current in type I hair cells enzymatically dissociated from rat semicircular canal crista ampullaris. Calcium current in type I hair cells exhibited a slow inactivation (during 2-s depolarizing steps), was sensitive to nimodipine and was blocked by Cd(2+) and Ni(2+). This current was activated at potentials above -60 mV, had a mean half maximal activation of -36 mV, and exhibited no steady-state inactivation at holding potentials between -100 and -60 mV. This data led us to conclude that hair cell Ca(2+) current is most likely of the L type. Thus, other mechanisms participating in neurotransmitter release such as K(+) accumulation in the synaptic cleft, modulation of K(+) currents by nitric oxide, participation of a Na(+) current and possible metabotropic cascades activated by depolarization should be considered.

BRLSC: An Advanced Eulerian Code for Predicting Shaped Charges. Volume 1

DTIC Science & Technology

1975-12-01

of cell. sec sec sec cm 124 J 𔃽 Variable Name Location Dimension Units Definition ECK ■2(76)- -1 -f n n EMI.V »Z(8S) EMOB =Z...energy sum: (2-r Ek - ETI1 j/ETII; where E^ is total energy in cell K. If | ECK | > DMIN, execution is stopped. INPUT parameter. Mininum specific...NMXCLS 74. BBOUND 75. UN 7 5 76. ECK 77. NECYCL 78. NTPMX 79. UN 7 9 80. UVMAX 81. NTCC 82. UN S 2 83. IVARDX 84. T Sb. EM IN S6. PMIN

Red and blue shift of liquid water's excited states: A many body perturbation study

NASA Astrophysics Data System (ADS)

Ziaei, Vafa; Bredow, Thomas

2016-08-01

In the present paper, accurate optical absorption spectrum of liquid H2O is calculated in the energy range of 5-20 eV to probe the nature of water's excited states by means of many body perturbation approach. Main features of recent inelastic X-ray measurements are well reproduced, such as a bound excitonic peak at 7.9 eV with a shoulder at 9.4 eV as well as the absorption maximum at 13.9 eV, followed by a broad shoulder at 18.4 eV. The spectrum is dominated by excitonic effects impacting the structures of the spectrum at low and higher energy regimes mixed by single particle effects at high energies. The exciton distribution of the low-energy states, in particular of S1, is highly anisotropic and localized mostly on one water molecule. The S1 state is essentially a HOCO-LUCO (highest occupied crystal orbital - lowest unoccupied crystal orbital) transition and of intra-molecular type, showing a localized valence character. Once the excitation energy is increased, a significant change in the character of the electronically excited states occurs, characterized through emergence of multiple quasi-particle peaks at 7.9 eV in the quasi-particle (QP) transition profile and in the occurring delocalized exciton density distribution, spread over many more water molecules. The exciton delocalization following a change of the character of excited states at around 7.9 eV causes the blue shift of the first absorption band with respect to water monomer S1. However, due to reduction of the electronic band gap from gas to liquid phase, following enhanced screening upon condensation, the localized S1 state of liquid water is red-shifted with respect to S1 state of water monomer. For higher excitations, near vertical ionization energy (11 eV), quasi-free electrons emerge, in agreement with the conduction band electron picture. Furthermore, the occurring red and blue shift of the excited states are independent of the coupling of resonant and anti-resonant contributions to the spectrum.

Red and blue shift of liquid water’s excited states: A many body perturbation study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziaei, Vafa, E-mail: ziaei@thch.uni-bonn.de; Bredow, Thomas, E-mail: bredow@thch.uni-bonn.de

In the present paper, accurate optical absorption spectrum of liquid H{sub 2}O is calculated in the energy range of 5–20 eV to probe the nature of water’s excited states by means of many body perturbation approach. Main features of recent inelastic X-ray measurements are well reproduced, such as a bound excitonic peak at 7.9 eV with a shoulder at 9.4 eV as well as the absorption maximum at 13.9 eV, followed by a broad shoulder at 18.4 eV. The spectrum is dominated by excitonic effects impacting the structures of the spectrum at low and higher energy regimes mixed by singlemore » particle effects at high energies. The exciton distribution of the low-energy states, in particular of S{sub 1}, is highly anisotropic and localized mostly on one water molecule. The S{sub 1} state is essentially a HOCO-LUCO (highest occupied crystal orbital - lowest unoccupied crystal orbital) transition and of intra-molecular type, showing a localized valence character. Once the excitation energy is increased, a significant change in the character of the electronically excited states occurs, characterized through emergence of multiple quasi-particle peaks at 7.9 eV in the quasi-particle (QP) transition profile and in the occurring delocalized exciton density distribution, spread over many more water molecules. The exciton delocalization following a change of the character of excited states at around 7.9 eV causes the blue shift of the first absorption band with respect to water monomer S{sub 1}. However, due to reduction of the electronic band gap from gas to liquid phase, following enhanced screening upon condensation, the localized S{sub 1} state of liquid water is red-shifted with respect to S{sub 1} state of water monomer. For higher excitations, near vertical ionization energy (11 eV), quasi-free electrons emerge, in agreement with the conduction band electron picture. Furthermore, the occurring red and blue shift of the excited states are independent of the coupling of resonant and anti-resonant contributions to the spectrum.« less

Distinct Characteristics of Small Cell Lung Cancer Correlate With Central or Peripheral Origin: Subtyping Based on Location and Expression of Transcription Factor TTF-1.

PubMed

Miyauchi, Eisaku; Motoi, Noriko; Ono, Hiroshi; Ninomiya, Hironori; Ohyanagi, Fumiyoshi; Nishio, Makoto; Okumura, Sakae; Ichinose, Masakazu; Ishikawa, Yuichi

2015-12-01

Small-cell lung carcinoma (SCLC) is a type of lung cancer with neuroendocrine differentiation and a poor prognosis that is widely believed to arise in the central lung. Thyroid transcription factor-1 (TTF-1) is a peripheral marker of lung adenocarcinoma that is also highly expressed in SCLC. In this study, we examined whether SCLC is really a central-type tumor and the relationship between tumor location, TTF-1 expression and prognosis of SCLC.Ninety six SCLCs, diagnosed from biopsies or surgical materials, for which detailed computed tomography (CT) images were available, were collected consecutively from Japanese patients between 2004 and 2011. We examined the location of the primary tumor (central or peripheral) using thin-sliced CT, a TTF-1 immunohistochemical expression, and clinicopathology including prognosis.Of the 96 SCLCs, 74% (71/96) were of the peripheral type and found to have a significantly worse prognosis than central-type tumors. TTF-1 immunoreactivity was identified in 79 tumors (82%), 78% of which (62/79) were of the peripheral type and 22% of which were central. TTF-1 expression was significantly correlated with peripheral location (P = 0.030). Multivariate analysis revealed that high TNM stages and the peripheral location were independent markers for poor survival.The majority of SCLCs were of the peripheral type. The peripheral-type SCLC expressed TTF-1 more frequently and had a poorer prognosis than central-type tumors did. Further analysis on original sites of SCLC, using molecular methodology, or based on another ethnicity, should be warranted.

Human Adenovirus Type 37 Uses αVβ1 and α3β1 Integrins for Infection of Human Corneal Cells

PubMed Central

Storm, Rickard J.; Persson, B. David; Skalman, Lars Nygård; Frängsmyr, Lars; Lindström, Mona; Rankin, Greg; Lundmark, Richard; Domellöf, Fatima Pedrosa

2016-01-01

ABSTRACT Epidemic keratoconjunctivitis (EKC) is a severe, contagious ocular disease that affects 20 to 40 million individuals worldwide every year. EKC is mainly caused by six types of human adenovirus (HAdV): HAdV-8, -19, -37, -53, -54, and -56. Of these, HAdV-8, -19, and -37 use sialic acid-containing glycans as cellular receptors. αVβ3, αVβ5, and a few additional integrins facilitate entry and endosomal release of other HAdVs. With the exception of a few biochemical analyses indicating that HAdV-37 can interact physically with αVβ5, little is known about the integrins used by EKC-causing HAdVs. Here, we investigated the overall integrin expression on human corneal cells and found expression of α2, α3, α6, αV, β1, and β4 subunits in human corneal in situ epithelium and/or in a human corneal epithelial (HCE) cell line but no or less accessible expression of α4, α5, β3, or β5. We also identified the integrins used by HAdV-37 through a series of binding and infection competition experiments and different biochemical approaches. Together, our data suggest that HAdV-37 uses αVβ1 and α3β1 integrins for infection of human corneal epithelial cells. Furthermore, to confirm the relevance of these integrins in the HAdV-37 life cycle, we developed a corneal multilayer tissue system and found that HAdV-37 infection correlated well with the patterns of αV, α3, and β1 integrin expression. These results provide further insight into the tropism and pathogenesis of EKC-causing HAdVs and may be of importance for future development of new antiviral drugs. IMPORTANCE Keratitis is a hallmark of EKC, which is caused by six HAdV types (HAdV-8, -19, -37, -53, -54, and -56). HAdV-37 and some other HAdV types interact with integrin αVβ5 in order to enter nonocular human cells. In this study, we found that αVβ5 is not expressed on human corneal epithelial cells, thus proposing other host factors mediate corneal infection. Here, we first characterized integrin expression patterns on corneal tissue and corneal cells. Among the integrins identified, competition binding and infection experiments and biochemical assays pointed out αVβ1 and α3β1 to be of importance for HAdV-37 infection of corneal tissue. In the absence of a good animal model for EKC-causing HAdVs, we also developed an in vitro system with multilayer HCE cells and confirmed the relevance of the suggested integrins during HAdV-37 infection. PMID:27974569

A homozygous nonsense mutation in the gene for Tmem79, a component for the lamellar granule secretory system, produces spontaneous eczema in an experimental model of atopic dermatitis.

PubMed

Sasaki, Takashi; Shiohama, Aiko; Kubo, Akiharu; Kawasaki, Hiroshi; Ishida-Yamamoto, Akemi; Yamada, Taketo; Hachiya, Takayuki; Shimizu, Atsushi; Okano, Hideyuki; Kudoh, Jun; Amagai, Masayuki

2013-11-01

Flaky tail (ma/ma Flg(ft/ft)) mice have a frameshift mutation in the filaggrin (Flg(ft)) gene and are widely used as a model of human atopic dermatitis associated with FLG mutations. These mice possess another recessive hair mutation, matted (ma), and develop spontaneous dermatitis under specific pathogen-free conditions, whereas genetically engineered Flg(-/-) mice do not. We identified and characterized the gene responsible for the matted hair and dermatitis phenotype in flaky tail mice. We narrowed down the responsible region by backcrossing ma/ma mice with wild-type mice and identified the mutation using next-generation DNA sequencing. We attempted to rescue the matted phenotype by introducing the wild-type matted transgene. We characterized the responsible gene product by using whole-mount immunostaining of epidermal sheets. We demonstrated that ma, but not Flg(ft), was responsible for the dermatitis phenotype and corresponded to a Tmem79 gene nonsense mutation (c.840C>G, p.Y280*), which encoded a 5-transmembrane protein. Exogenous Tmem79 expression rescued the matted hair and dermatitis phenotype of Tmem79(ma/ma) mice. Tmem79 was mainly expressed in the trans-Golgi network in stratum granulosum cells in the epidermis in both mice and humans. The Tmem79(ma/ma) mutation impaired the lamellar granule secretory system, which resulted in altered stratum corneum formation and a subsequent spontaneous dermatitis phenotype. The Tmem79(ma/ma) mutation is responsible for the spontaneous dermatitis phenotype in matted mice, probably as a result of impaired lamellar granule secretory system and altered stratum corneum barrier function. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Cyclic-RGDyC functionalized liposomes for dual-targeting of tumor vasculature and cancer cells in glioblastoma: An in vitro boron neutron capture therapy study.

PubMed

Kang, Weirong; Svirskis, Darren; Sarojini, Vijayalekshmi; McGregor, Ailsa L; Bevitt, Joseph; Wu, Zimei

2017-05-30

The efficacy of boron neutron capture therapy depends on the selective delivery of 10B to the target. Integrins αvβ3 are transmembrane receptors over-expressed in both glioblastoma cells and its neovasculature. In this study, a novel approach to dual-target glioblastoma vasculature and tumor cells was investigated. Liposomes (124 nm) were conjugated with a αvβ3 ligand, cyclic arginine-glycine-aspartic acid-tyrosine-cysteine peptide (c(RGDyC)-LP) (1% molar ratio) through thiol-maleimide coupling. Expression of αvβ3 in glioblastoma cells (U87) and human umbilical vein endothelial cells (HUVEC), representing tumor angiogenesis, was determined using Western Blotting with other cells as references. The results showed that both U87 and HUVEC had stronger expression of αvβ3 than other cell types, and the degree of cellular uptake of c(RGDyC)-LP correlated with the αvβ3-expression levels of the cells. In contrast, control liposomes without c(RGDyC) showed little cellular uptake, regardless of cell type. In an in vitro boron neutron capture therapy study, the c(RGDyC)-LP containing sodium borocaptate generated more rapid and significant lethal effects to both U87 and HUVEC than the control liposomes and drug solution. Interestingly, neutron irradiated U87 and HUVEC showed different types of subsequent cell death. In conclusion, this study has demonstrated the potential of a new dual-targeting strategy using c(RGDyC)-LP to improve boron neutron capture therapy for glioblastoma.

Cyclic-RGDyC functionalized liposomes for dual-targeting of tumor vasculature and cancer cells in glioblastoma: An in vitro boron neutron capture therapy study

PubMed Central

Kang, Weirong; Svirskis, Darren; Sarojini, Vijayalekshmi; McGregor, Ailsa L.; Bevitt, Joseph; Wu, Zimei

2017-01-01

The efficacy of boron neutron capture therapy depends on the selective delivery of 10B to the target. Integrins αvβ3 are transmembrane receptors over-expressed in both glioblastoma cells and its neovasculature. In this study, a novel approach to dual-target glioblastoma vasculature and tumor cells was investigated. Liposomes (124 nm) were conjugated with a αvβ3 ligand, cyclic arginine-glycine-aspartic acid-tyrosine-cysteine peptide (c(RGDyC)-LP) (1% molar ratio) through thiol-maleimide coupling. Expression of αvβ3 in glioblastoma cells (U87) and human umbilical vein endothelial cells (HUVEC), representing tumor angiogenesis, was determined using Western Blotting with other cells as references. The results showed that both U87 and HUVEC had stronger expression of αvβ3 than other cell types, and the degree of cellular uptake of c(RGDyC)-LP correlated with the αvβ3-expression levels of the cells. In contrast, control liposomes without c(RGDyC) showed little cellular uptake, regardless of cell type. In an in vitro boron neutron capture therapy study, the c(RGDyC)-LP containing sodium borocaptate generated more rapid and significant lethal effects to both U87 and HUVEC than the control liposomes and drug solution. Interestingly, neutron irradiated U87 and HUVEC showed different types of subsequent cell death. In conclusion, this study has demonstrated the potential of a new dual-targeting strategy using c(RGDyC)-LP to improve boron neutron capture therapy for glioblastoma. PMID:28402271

n+ GaAs/AuGeNi-Au Thermocouple-Type RF MEMS Power Sensors Based on Dual Thermal Flow Paths in GaAs MMIC

PubMed Central

Zhang, Zhiqiang; Liao, Xiaoping

2017-01-01

To achieve radio frequency (RF) power detection, gain control, and circuit protection, this paper presents n+ GaAs/AuGeNi-Au thermocouple-type RF microelectromechanical system (MEMS) power sensors based on dual thermal flow paths. The sensors utilize a conversion principle of RF power-heat-voltage, where a thermovoltage is obtained as the RF power changes. To improve the heat transfer efficiency and the sensitivity, structures of two heat conduction paths are designed: one in which a thermal slug of Au is placed between two load resistors and hot junctions of the thermocouples, and one in which a back cavity is fabricated by the MEMS technology to form a substrate membrane underneath the resistors and the hot junctions. The improved sensors were fabricated by a GaAs monolithic microwave integrated circuit (MMIC) process. Experiments show that these sensors have reflection losses of less than −17 dB up to 12 GHz. At 1, 5, and 10 GHz, measured sensitivities are about 63.45, 53.97, and 44.14 µV/mW for the sensor with the thermal slug, and about 111.03, 94.79, and 79.04 µV/mW for the sensor with the thermal slug and the back cavity, respectively. PMID:28629144

n⁺ GaAs/AuGeNi-Au Thermocouple-Type RF MEMS Power Sensors Based on Dual Thermal Flow Paths in GaAs MMIC.

PubMed

Zhang, Zhiqiang; Liao, Xiaoping

2017-06-17

To achieve radio frequency (RF) power detection, gain control, and circuit protection, this paper presents n⁺ GaAs/AuGeNi-Au thermocouple-type RF microelectromechanical system (MEMS) power sensors based on dual thermal flow paths. The sensors utilize a conversion principle of RF power-heat-voltage, where a thermovoltage is obtained as the RF power changes. To improve the heat transfer efficiency and the sensitivity, structures of two heat conduction paths are designed: one in which a thermal slug of Au is placed between two load resistors and hot junctions of the thermocouples, and one in which a back cavity is fabricated by the MEMS technology to form a substrate membrane underneath the resistors and the hot junctions. The improved sensors were fabricated by a GaAs monolithic microwave integrated circuit (MMIC) process. Experiments show that these sensors have reflection losses of less than -17 dB up to 12 GHz. At 1, 5, and 10 GHz, measured sensitivities are about 63.45, 53.97, and 44.14 µ V/mW for the sensor with the thermal slug, and about 111.03, 94.79, and 79.04 µ V/mW for the sensor with the thermal slug and the back cavity, respectively.

Intracellular survival of virulence and low-virulence strains of Vibrio parahaemolyticus in Epinephelus awoara macrophages and peripheral leukocytes.

PubMed

Xu, X J; Sang, B H; Chen, W B; Yan, Q P; Xiong, Z Y; Su, J B; Zou, W Z

2015-01-30

In this study, we examined the virulence factors and pathogenesis of Vibrio parahaemolyticus in Epinephelus awoara. The chemotactic motility of V. parahaemolyticus for phagocytosis and intracellular survival in fish macrophages was determined using virulence strains and low-virulence strains of V. parahaemolyticus. We found that the intracellular mean number of virulence strains of V. parahaemolyticus ranged from 0-180 min after co-incubation with macrophages and peripheral leukocytes, was relatively low, and decreased steadily over the observation period. Low-virulence strains of V. parahaemolyticus were unable to survive in peripheral leukocytes and macrophages. Cell viability in response to V. parahaemolyticus was assessed using the MTT assay. Low-virulence V. parahaemolyticus strains exhibited lower cytotoxicity compared to virulent strains. The average percent of live macrophages and peripheral leukocytes infected by V. parahaemolyticus ranged from 13.50-79.20%. These results indicate that V. parahaemolyticus in E. awoara is a facultative intracellular bacterium that may be involved in virulence.

A silencing suppressor protein (NSs) of a tospovirus enhances baculovirus replication in permissive and semipermissive insect cell lines.

PubMed

Oliveira, Virgínia Carla; Bartasson, Lorrainy; de Castro, Maria Elita Batista; Corrêa, José Raimundo; Ribeiro, Bergmann Morais; Resende, Renato Oliveira

2011-01-01

The nonstructural protein (NSs) of the Tomato spotted wilt virus (TSWV) has been identified as an RNAi suppressor in plant cells. A recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) designated vAcNSs, containing the NSs gene under the control of the viral polyhedrin (polh) gene promoter, was constructed and the effects of NSs in permissive, semipermissive and nonpermissive insect cells to vAcNSs infection were evaluated. vAcNSs produced more budded virus when compared to wild type in semipermissive cells. Co-infection of vAcNSs with wild type baculoviruses clearly enhanced polyhedra production in all host cells. Confocal microscopy analysis showed that NSs accumulated in abundance in the cytoplasm of permissive and semipermissive cells. In contrast, high amounts of NSs were detected in the nuclei of nonpermissive cells. Co-infection of vAcNSs with a recombinant AcMNPV containing the enhanced green fluorescent protein (egfp) gene, significantly increased EGFP expression in semipermissive cells and in Anticarsia gemmatalis-hemocytes. Absence of small RNA molecules of egfp transcripts in this cell line and in a permissive cell line indicates the suppression of gene silencing activity. On the other hand, vAcNSs was not able to suppress RNAi in a nonpermissive cell line. Our data showed that NSs protein of TSWV facilitates baculovirus replication in different lepidopteran cell lines, and these results indicate that NSs could play a similar role during TSWV-infection in its thrips vector. Copyright © 2010 Elsevier B.V. All rights reserved.

Targeting glutamine metabolism in myeloproliferative neoplasms

PubMed Central

Zhan, Huichun; Ciano, Kristen; Dong, Katherine; Zucker, Stanley

2016-01-01

JAK2V617F mutation can be detected in the majority of myeloproliferative neoplasm (MPN) patients. The JAK2 inhibitor Ruxolitinib is the first FDA-approved treatment for MPNs. However, its use is limited by various dose related toxicities. Here, we studied the metabolic state and glutamine metabolism of BaF3-hEPOR-JAK2V617F and BaF3-hEPOR-JAK2WT cells. We found that the JAK2V617F-mutant cells were associated with increased oxygen consumption rate and extracellular acidification rate than the JAK2WT cells and there was an increased glutamine metabolism in JAK2V617F-mutant cells compared to wild-type cells. Glutaminase (GLS), the key enzyme in gluta-mine metabolism, was upregulated in the JAK2V617F-mutant BaF3 cells compared to the JAK2WT BaF3 cells. In MPN patient peripheral blood CD34+ cells, GLS expression was increased in JAK2V617F-mutant progenitor cells compared to JAK2 wild-type progenitor cells from the same patients and GLS levels were increased at the time of disease progression compared to at earlier time points. Moreover, GLS inhibitor increased the growth inhibitory effect of Ruxolitinib in both JAK2V617F-mutant cell lines and peripheral blood CD34+ cells from MPN patients. Therefore, GLS inhibitor should be further explored to enhance the therapeutic effectiveness of JAK2 inhibitor and allow the administration of lower doses of the drug to avoid its toxicity. PMID:26227854

Biphasic voltage-dependent inactivation of human NaV 1.3, 1.6 and 1.7 Na+ channels expressed in rodent insulin-secreting cells.

PubMed

Godazgar, Mahdieh; Zhang, Quan; Chibalina, Margarita V; Rorsman, Patrik

2018-05-01

Na + current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na + (Na V ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single Na V subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that Na V channels adopt different inactivation behaviours depending on the local membrane environment. Pancreatic β-cells are equipped with voltage-gated Na + channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na + current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na + channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different Na V α-subunits. We tested this possibility by expression of TTX-resistant variants of the Na V subunits found in β-cells (Na V 1.3, Na V 1.6 and Na V 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all Na V subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. Na V 1.7 inactivated at 15--20 mV more negative membrane potentials than Na V 1.3 and Na V 1.6 in Ins1 cells but this small difference is insufficient to solely explain the biphasic inactivation in Ins1 cells. In Ins1 cells, but never in the other cell types, widely different components of Na V inactivation (separated by 30 mV) were also observed following expression of a single type of Na V α-subunit. The more positive component exhibited a voltage dependence of inactivation similar to that found in HEK and CHO cells. We propose that biphasic Na V inactivation in insulin-secreting cells reflects insertion of channels in membrane domains that differ with regard to lipid and/or membrane protein composition. © 2018 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Design, development, fabrication and delivery of register and multiplexer units. [CMOS monolithic chip development

NASA Technical Reports Server (NTRS)

Feller, A.; Lombardi, T.

1978-01-01

Several approaches for implementing the register and multiplexer unit into two CMOS monolithic chip types were evaluated. The CMOS standard cell array technique was selected and implemented. Using this design automation technology, two LSI CMOS arrays were designed, fabricated, packaged, and tested for proper static, functional, and dynamic operation. One of the chip types, multiplexer register type 1, is fabricated on a 0.143 x 0.123 inch chip. It uses nine standard cell types for a total of 54 standard cells. This involves more than 350 transistors and has the functional equivalent of 111 gates. The second chip, multiplexer register type 2, is housed on a 0.12 x 0.12 inch die. It uses 13 standard cell types, for a total of 42 standard cells. It contains more than 300 transistors, the functional equivalent of 112 gates. All of the hermetically sealed units were initially screened for proper functional operation. The static leakage and the dynamic leakage were measured. Dynamic measurements were made and recorded. At 10 V, 14 megabit shifting rates were measured on multiplexer register type 1. At 5 V these units shifted data at a 6.6 MHz rate. The units were designed to operate over the 3 to 15 V operating range and over a temperature range of -55 to 125 C.

Elevated frequencies of micronuclei in pregnant women with type 1 diabetes mellitus and in their newborns.

PubMed

Witczak, Monika; Ferenc, Tomasz; Gulczyńska, Ewa; Nowakowska, Dorota; Łopaczyńska, Dobrosława; Wilczyński, Jan

2014-03-15

Pregestational diabetes mellitus (type 1 and type 2) affects about 1% of the obstetric population. In diabetes, persistent hyperglycemia can be a source of DNA damage via overproduction of reactive oxygen species (ROS). Using the cytokinesis-block micronucleus (CBMN) test, we measured the frequencies of micronuclei (MN) per 1000 binucleated (BN) cells in pregnant women (mothers) with type 1 diabetes mellitus (T1DM) and in their newborns. Peripheral blood lymphocytes were collected from 17 pregnant women with T1DM and cord-blood lymphocytes from their 17 newborns. The control group included 40 pregnant women (mothers) without diabetes mellitus (DM) and their 40 newborns. In the group of pregnant women with T1DM, the mean number of MN per 1000 BN cells was 2.35 (±1.07), significantly (p<0.001) higher than in the control group of pregnant women (0.86±0.90). The frequency value in the group of newborns of T1DM mothers was 1.42 (±0.60), significantly (p<0.05) higher than in the corresponding control group (0.67±0.79). The value in the group of mothers with T1DM was significantly (p<0.05) higher than in their newborns. Comparing mothers without DM with their newborns, no significant frequency differences were observed. No significant correlations were observed between MN frequencies in mothers with T1DM and either the frequencies in their newborns, the duration of diabetes, or HbA1C levels. Our results indicate that T1DM is accompanied by increased frequencies of MN in pregnant women and their newborns. Copyright © 2014 Elsevier B.V. All rights reserved.

Protection and attachment of Vibrio cholerae mediated by the toxin-coregulated pilus in the infant mouse model.

PubMed

Krebs, Shelly J; Taylor, Ronald K

2011-10-01

Colonization of the human small intestine by Vibrio cholerae is an essential step in pathogenesis that requires the type IV toxin-coregulated pilus (TCP). To date, three functions of TCP have been characterized: it serves as the CTXΦ receptor, secretes the colonization factor TcpF, and functions in microcolony formation by mediating bacterium-bacterium interactions. Although type IV pili in other pathogenic bacteria have been characterized as playing a major role in attachment to epithelial cells, there are very few studies to suggest that TCP acts as an attachment factor. Taking this into consideration, we investigated the function of TCP in attachment to Caco-2 cells and found that mutants lacking TCP were defective in attachment compared to the wild type. Overexpression of ToxT, the activator of TCP, significantly increased attachment of wild-type V. cholerae to Caco-2 cells. Using field-emission scanning electron microscopy (FESEM), we also observed TCP-mediated attachment to the small intestines of infected infant mice by using antibodies specific to TCP and V. cholerae. Remarkably, we also visualized matrices comprised of TCP appearing to engulf V. cholerae during infection, and we demonstrated that these matrices protected the bacteria from a component of bile, disclosing a possible new role of this pilus in protection of the bacterial cells from antimicrobial agents. This study provides new insights into TCP's function in V. cholerae colonization of the small intestine, describing additional roles in mediating attachment and protection of V. cholerae bacterial cells.

Complete Spontaneous Regression of Merkel Cell Carcinoma After Biopsy: A Case Report and Review of the Literature.

PubMed

Ahmadi Moghaddam, Parnian; Cornejo, Kristine M; Hutchinson, Lloyd; Tomaszewicz, Keith; Dresser, Karen; Deng, April; OʼDonnell, Patrick

2016-11-01

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumor that typically occurs on the head and neck of the elderly and follows an aggressive clinical course. Merkel cell polyomavirus (MCPyV) has been identified in up to 80% of cases and has been shown to participate in MCC tumorigenesis. Complete spontaneous regression of MCC has been rarely reported in the literature. We describe a case of a 79-year-old man that presented with a rapidly growing, 3-cm mass on the left jaw. An incisional biopsy revealed MCC. Additional health issues were discovered in the preoperative workup of this patient which delayed treatment. One month after the biopsy, the lesion showed clinical regression in the absence of treatment. Wide excision of the biopsy site with sentinel lymph node dissection revealed no evidence of MCC 2 months later. The tumor cells in the patient's biopsy specimen were negative for MCPyV by polymerase chain reaction and immunohistochemistry (CM2B4 antibody, Santa Cruz, CA). The exact mechanism for complete spontaneous regression in MCC is unknown. To our knowledge, only 2 previous studies evaluated the presence of MCPyV by polymerase chain reaction in MCC with spontaneous regression. Whether the presence or absence of MCPyV correlates with spontaneous regression warrants further investigation.

Receptor-Targeted Nipah Virus Glycoproteins Improve Cell-Type Selective Gene Delivery and Reveal a Preference for Membrane-Proximal Cell Attachment.

PubMed

Bender, Ruben R; Muth, Anke; Schneider, Irene C; Friedel, Thorsten; Hartmann, Jessica; Plückthun, Andreas; Maisner, Andrea; Buchholz, Christian J

2016-06-01

Receptor-targeted lentiviral vectors (LVs) can be an effective tool for selective transfer of genes into distinct cell types of choice. Moreover, they can be used to determine the molecular properties that cell surface proteins must fulfill to act as receptors for viral glycoproteins. Here we show that LVs pseudotyped with receptor-targeted Nipah virus (NiV) glycoproteins effectively enter into cells when they use cell surface proteins as receptors that bring them closely enough to the cell membrane (less than 100 Å distance). Then, they were flexible in receptor usage as demonstrated by successful targeting of EpCAM, CD20, and CD8, and as selective as LVs pseudotyped with receptor-targeted measles virus (MV) glycoproteins, the current standard for cell-type specific gene delivery. Remarkably, NiV-LVs could be produced at up to two orders of magnitude higher titers compared to their MV-based counterparts and were at least 10,000-fold less effectively neutralized than MV glycoprotein pseudotyped LVs by pooled human intravenous immunoglobulin. An important finding for NiV-LVs targeted to Her2/neu was an about 100-fold higher gene transfer activity when particles were targeted to membrane-proximal regions as compared to particles binding to a more membrane-distal epitope. Likewise, the low gene transfer activity mediated by NiV-LV particles bound to the membrane distal domains of CD117 or the glutamate receptor subunit 4 (GluA4) was substantially enhanced by reducing receptor size to below 100 Å. Overall, the data suggest that the NiV glycoproteins are optimally suited for cell-type specific gene delivery with LVs and, in addition, for the first time define which parts of a cell surface protein should be targeted to achieve optimal gene transfer rates with receptor-targeted LVs.

Electrophysiological properties of myocytes isolated from the mouse atrioventricular node: L-type ICa, IKr, If, and Na-Ca exchange.

PubMed

Choisy, Stéphanie C; Cheng, Hongwei; Orchard, Clive H; James, Andrew F; Hancox, Jules C

2015-11-01

The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. This study investigated the electrophysiology of cells isolated from the AVN region of adult mouse hearts, and compared murine ionic current magnitude with that of cells from the more extensively studied rabbit AVN. Whole-cell patch-clamp recordings of ionic currents, and perforated-patch recordings of action potentials (APs), were made at 35-37°C. Hyperpolarizing voltage commands from -40 mV elicited a Ba(2+)-sensitive inward rectifier current that was small at diastolic potentials. Some cells (Type 1; 33.4 ± 2.2 pF; n = 19) lacked the pacemaker current, If, whilst others (Type 2; 34.2 ± 1.5 pF; n = 21) exhibited a clear If, which was larger than in rabbit AVN cells. On depolarization from -40 mV L-type Ca(2+) current, IC a,L, was elicited with a half maximal activation voltage (V0.5) of -7.6 ± 1.2 mV (n = 24). IC a,L density was smaller than in rabbit AVN cells. Rapid delayed rectifier (IK r) tail currents sensitive to E-4031 (5 μmol/L) were observed on repolarization to -40 mV, with an activation V0.5 of -10.7 ± 4.7 mV (n = 8). The IK r magnitude was similar in mouse and rabbit AVN. Under Na-Ca exchange selective conditions, mouse AVN cells exhibited 5 mmol/L Ni-sensitive exchange current that was inwardly directed negative to the holding potential (-40 mV). Spontaneous APs (5.2 ± 0.5 sec(-1); n = 6) exhibited an upstroke velocity of 37.7 ± 16.2 V/s and ceased following inhibition of sarcoplasmic reticulum Ca(2+) release by 1 μmol/L ryanodine, implicating intracellular Ca(2+) cycling in murine AVN cell electrogenesis. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Melatonin and its precursors in Y79 human retinoblastoma cells - Effect of sodium butyrate

NASA Technical Reports Server (NTRS)

Deng, Mei H.; Lopez G.-Coviella, Ignacio; Lynch, Harry J.; Wurtman, Richard J.

1991-01-01

We studied the release of melatonin and the production of its precursors, 5-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for three days. This protocol dramatically increased the release of melatonin, and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine or L-DOPA markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 ceils.

A morphological and immunophenotypic map of the immune response in Merkel cell carcinoma.

PubMed

Walsh, Noreen M; Fleming, Kirsten E; Hanly, John G; Dakin Hache, Kelly; Doucette, Steve; Ferrara, Gerardo; Cerroni, Lorenzo

2016-06-01

The susceptibility of Merkel cell carcinoma to the host immune response has prompted a search for effective immunotherapy. CD8-positive T lymphocytes are considered key effectors of this response, but the cellular infiltrates also harbor tumor-protective agents. By developing a comprehensive morphological and immunophenotypic map of tumor-infiltrating lymphocytes (TILS) in Merkel cell carcinoma, we aimed to establish a useful template for future studies. Twenty-two cases (mean age, 79years [range, 52-95]; male-female ratio, 10:12) were studied. TILS were categorized as brisk (7), nonbrisk (9), and absent(6). Merkel cell polyomavirus (MCPyV)-positive (16) and -negative (6) cases were included, as were those with pure (18) and combined (4) morphologies. One MCPyV+ case had undergone spontaneous regression. Immunohistochemical markers included CD3, CD4, CD8, CD20, CD68, FoxP3, PD-1, and CD123. Statistical analysis used Fisher exact tests and Spearman correlations. There was a significant correlation between brisk TILs and MCPyV+ status (P=.025). CD8+ T lymphocytes predominated, were present in significantly higher proportions in brisk infiltrates (P=.003), and showed a significant predilection for the intratumoral environment (P=.003). Immune inhibitors including T regulatory cells (FOXP3+) and PD-1+ "exhausted" immunocytes were present in lower proportions. Our findings support (1) the link between a brisk immune response and MCPyV positivity, (2) the supremacy of CD8+ cells in effecting immunity, and (3) the incorporation of immune inhibitors within the global infiltrate. Efforts to therapeutically arm the "effectors" and disarm the "detractors" are well focused. These will likely have the greatest impact on MCPyV-positive cases. Copyright © 2016 Elsevier Inc. All rights reserved.

Polarization characteristics of a low catalyst loading PEM water electrolyzer operating at elevated temperature

NASA Astrophysics Data System (ADS)

Lee, Byung-Seok; Park, Hee-Young; Choi, Insoo; Cho, Min Kyung; Kim, Hyoung-Juhn; Yoo, Sung Jong; Henkensmeier, Dirk; Kim, Jin Young; Nam, Suk Woo; Park, Sehkyu; Lee, Kwan-Young; Jang, Jong Hyun

2016-03-01

The effect of temperature and pressure, and diffusion layer thickness is assessed on performance of a proton exchange membrane water electrolyzers (PEMWEs) with an ultralow iridium oxide (IrO2) loading (0.1 mg cm-2) anode prepared by electrodeposition and a Pt/C catalyzed cathode with a Pt loading of 0.4 mg cm-2. Increasing pressure to 2.5 bar at 120 °C enhances the water electrolysis current, so the anode electrodeposited with 0.1 mg cm-2 IrO2 gives a current density of 1.79 A cm-2 at 1.6 V, which is comparable to the conventional powder-type IrO2 electrode with 2.0 mg cm-2 at a temperature of 120 °C and pressure of 2.5 bar. The major factors for cell performances are rationalized in terms of overpotentials, water flow rates and thickness of diffusion layers, based on polarization behavior and ac-impedance response.

Cell oxidation-reduction imbalance after modulated radiofrequency radiation.

PubMed

Marjanovic, Ana Marija; Pavicic, Ivan; Trosic, Ivancica

2015-01-01

Aim of this study was to evaluate an influence of modulated radiofrequency field (RF) of 1800 MHz, strength of 30 V/m on oxidation-reduction processes within the cell. The assigned RF field was generated within Gigahertz Transversal Electromagnetic Mode cell equipped by signal generator, modulator, and amplifier. Cell line V79, was irradiated for 10, 30, and 60 min, specific absorption rate was calculated to be 1.6 W/kg. Cell metabolic activity and viability was determined by MTT assay. In order to define total protein content, colorimetric method was used. Concentration of oxidised proteins was evaluated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) marked with fluorescent probe 2',7'-dichlorofluorescin diacetate were measured by means of plate reader device. In comparison with control cell samples, metabolic activity and total protein content in exposed cells did not differ significantly. Concentrations of carbonyl derivates, a product of protein oxidation, insignificantly but continuously increase with duration of exposure. In exposed samples, ROS level significantly (p < 0.05) increased after 10 min of exposure. Decrease in ROS level was observed after 30-min treatment indicating antioxidant defence mechanism activation. In conclusion, under the given laboratory conditions, modulated RF radiation might cause impairment in cell oxidation-reduction equilibrium within the growing cells.

Exploratory development of an electrically rechargeable lithium battery

NASA Astrophysics Data System (ADS)

Abraham, K. M.; Goldman, J. L.; Dempsey, M. D.; Holleck, G. L.

1980-10-01

The cathodic behavior or V6013 was investigated in rechargeable Li cells of the type, Li/2Me-THF,LiAsF6/V6013,C. Two forms of V6013 were synthesized and characterized. These were a stoichiometric form, i.e., V02.17, and a slightly non-stoichiometric form, i.e., V02.19. Stoichiometric V6013 was prepared by heating requisite quantities of V205 and V powder for 24 hrs. at 650 C. The slightly non-stoichiometric V6013 was prepared by the thermal decomposition of NH4V03 at 450 C. The discharge characteristics of the stoichiometric oxide at 60 C were similar to that of non-stoichiometric oxide at room temperature. The rechargeability of both the oxides were found to be sensitive to the lower voltage cutoff. The safest limits of cycling were 3.0 and 1.9V. Potentiostatic discharges of the oxides between 1.9 and 1.3V revealed a high capacity irreversible reduction process at about 1.6V. Three types of hermetically sealed cells were constructed and tested. In a high capacity (5Ah) prismatic cell utilizing the non-stoichiometric oxide, energy densities of 106 Whr/kg and 190 Whr/DM3 were achieved.

IL-17–dependent cellular immunity to collagen type V predisposes to obliterative bronchiolitis in human lung transplants

PubMed Central

Burlingham, William J.; Love, Robert B.; Jankowska-Gan, Ewa; Haynes, Lynn D.; Xu, Qingyong; Bobadilla, Joseph L.; Meyer, Keith C.; Hayney, Mary S.; Braun, Ruedi K.; Greenspan, Daniel S.; Gopalakrishnan, Bagavathi; Cai, Junchao; Brand, David D.; Yoshida, Shigetoshi; Cummings, Oscar W.; Wilkes, David S.

2007-01-01

Bronchiolitis obliterans syndrome (BOS), a process of fibro-obliterative occlusion of the small airways in the transplanted lung, is the most common cause of lung transplant failure. We tested the role of cell-mediated immunity to collagen type V [col(V)] in this process. PBMC responses to col(II) and col(V) were monitored prospectively over a 7-year period. PBMCs from lung transplant recipients, but not from healthy controls or col(IV)-reactive Goodpasture’s syndrome patients after renal transplant, were frequently col(V) reactive. Col(V)-specific responses were dependent on both CD4+ T cells and monocytes and required both IL-17 and the monokines TNF-α and IL-1β. Strong col(V)-specific responses were associated with substantially increased incidence and severity of BOS. Incidences of acute rejection, HLA-DR mismatched transplants, and induction of HLA-specific antibodies in the transplant recipient were not as strongly associated with a risk of BOS. These data suggest that while alloimmunity initiates lung transplant rejection, de novo autoimmunity mediated by col(V)-specific Th17 cells and monocyte/macrophage accessory cells ultimately causes progressive airway obliteration. PMID:17965778

Electrical filtering in gerbil isolated type I semicircular canal hair cells

NASA Technical Reports Server (NTRS)

Rennie, K. J.; Ricci, A. J.; Correia, M. J.

1996-01-01

1. Membrane potential responses of dissociated gerbil type I semicircular canal hair cells to current injections in whole cell current-clamp have been measured. The input resistance of type I cells was 21.4 +/- 14.3 (SD) M omega, (n = 25). Around the zero-current potential (Vz = -66.6 +/- 9.3 mV, n = 25), pulsed current injections (from approximately -200 to 750 pA) produced only small-amplitude, pulse-like changes in membrane potential. 2. Injecting constant current to hyperpolarize the membrane to around -100 mV resulted in a approximately 10-fold increase in membrane resistance. Current pulses superimposed on this constant hyperpolarization produced larger and more complex membrane potential changes. Depolarizing currents > or = 200 pA caused a rapid transient peak voltage before a plateau. 3. Membrane voltage was able to faithfully follow sine-wave current injections around Vz over the range 1-1,000 Hz with < 25% attenuation at 1 kHz. A previously described K conductance, IKI, which is active at Vz, produces the low input resistance and frequency response. This was confirmed by pharmacologically blocking IKI. This conductance, present in type I cells but not type II hair cells, would appear to confer on type I cells a lower gain, but a much broader bandwidth at Vz, than seen in type II cells.

Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca(2+) Channels.

PubMed

Pellegrini, Chiara; Lecci, Sandro; Lüthi, Anita; Astori, Simone

2016-04-01

Low-threshold voltage-gated T-type Ca(2+) channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca(2+) currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10-15 Hz), which was accompanied by an increase in the δ band (1-4 Hz). Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms. © 2016 Associated Professional Sleep Societies, LLC.

Assessment of Boron Steels for Army Use

DTIC Science & Technology

1978-11-01

I IA-79-0120 5 ys-g Aofc34V5 TECHNICAL LIBRARY AD ASSESSMENT OF BORON STEELS FOR ARMVlysr 3 ,% gL&tm tew^ / „»-^~ « "’"s4...ej ASSESSMENT OF BORON STEELS FOR ARMY USE 5. TYPE OF REPORT & PERIOD COVERED Final Report 6 PERFORMING ORG. REPORT NUMBER 7...reverse side 11 necessery rmd identify by block number) Boron steels Alloy conservation Alloy substitution Materials shortages 20. ABSTRACT

Calcium/calmodulin-dependent serine protein kinase CASK modulates the L-type calcium current.

PubMed

Nafzger, Sabine; Rougier, Jean-Sebastien

2017-01-01

The L-type voltage-gated calcium channel Ca v 1.2 mediates the calcium influx into cells upon membrane depolarization. The list of cardiopathies associated to Ca v 1.2 dysfunctions highlights the importance of this channel in cardiac physiology. Calcium/calmodulin-dependent serine protein kinase (CASK), expressed in cardiac cells, has been identified as a regulator of Ca v 2.2 channels in neurons, but no experiments have been performed to investigate its role in Ca v 1.2 regulation. Full length or the distal C-terminal truncated of the pore-forming Ca v 1.2 channel (Ca v 1.2α1c), both present in cardiac cells, were expressed in TsA-201 cells. In addition, a shRNA silencer, or scramble as negative control, of CASK was co-transfected in order to silence CASK endogenously expressed. Three days post-transfection, the barium current was increased only for the truncated form without alteration of the steady state activation and inactivation biophysical properties. The calcium current, however, was increased after CASK silencing with both types of Ca v 1.2α1c subunits suggesting that, in absence of calcium, the distal C-terminal counteracts the CASK effect. Biochemistry experiments did not reveals neither an alteration of Ca v 1.2 channel protein expression after CASK silencing nor an interaction between Ca v 1.2α1c subunits and CASK. Nevertheless, after CASK silencing, single calcium channel recordings have shown an increase of the voltage-gated calcium channel Ca v 1.2 open probability explaining the increase of the whole-cell current. This study suggests CASK as a novel regulator of Ca v 1.2 via a modulation of the voltage-gated calcium channel Ca v 1.2 open probability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative analyses of the behavior of exogenously added bacteria during an acidulocomposting process.

PubMed

Suematsu, Takatoshi; Yamashita, Satoshi; Hemmi, Hisashi; Yoshinari, Ayaka; Shimoyama, Takefumi; Nakayama, Toru; Nishino, Tokuzo

2012-07-01

The behavior of adventitious bacteria during an acidulocomposting process was quantitatively analyzed in garbage-free trials. The numbers of the added Bacillus subtilis and Pseudomonas putida cells diminished in a first-order manner with t(1/2) values of 0.45d and 0.79d, respectively, consistent with the observed stability of the acidulocomposting function. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Anthelmintic effects of the essential oil of fennel (Foeniculum vulgare Mill., Apiaceae) against Schistosoma mansoni.

PubMed

Wakabayashi, Kamila A L; de Melo, Nathalya I; Aguiar, Daniela P; de Oliveira, Pollyanna F; Groppo, Milton; da Silva Filho, Ademar A; Rodrigues, Vanderlei; Cunha, Wilson R; Tavares, Denise C; Magalhães, Lizandra G; Crotti, Antônio E M

2015-07-01

Foeniculum vulgare Mill. (Apiaceae), known as fennel, is a widespread aromatic herbaceous plant, and its essential oil is used as additive in the food, pharmaceutical, cosmetic, and perfume industries. The in vitro antischistosomal activity and cytotoxic effects against V79 cells of the essential oil of F. vulgare cultivated in southeastern Brazil (FV-EO) was investigated. The FV-EO was obtained by hydrodistillation and characterized by GC-FID and GC/MS analyses. (E)-Anethole (69.8%) and limonene (22.5%) were identified as the major constituents. Its anthelmintic activity against Schistosoma mansoni was evaluated at concentrations of 10, 50, and 100 μg/ml, and it was found to be active against adult S. mansoni worms, although it was less effective than the positive control praziquantel (PZQ) in terms of separation of the coupled pairs, mortality, and decreased motor activity. However, FV-EO elicited an interesting dose-dependent reduction in the number of S. mansoni eggs. On their own, (E)-anethole and the limonene enantiomers were much less effective than FV-EO and PZQ. An XTT-cytotoxicity-based assay evidenced no FV-EO cytotoxicity against V79 cells. In summary, FV-EO displayed moderate in vitro schistosomicidal activity against adult S. mansoni worms, exerted remarkable inhibitory effects on the egg development, and was of low toxicity. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danno, Katsunori; Kimoto, Tsunenobu

The authors have investigated deep levels in as-grown and electron-irradiated p-type 4H-SiC epilayers by deep level transient spectroscopy. In as-grown epilayers, the D center and four deep levels are observed. In p-type 4H-SiC, reactive ion etching followed by thermal treatment (at 1150 degree sign C) induces the HK0 (E{sub V}+0.79 eV) and HK2 (E{sub V}+0.84 eV) centers. By the electron irradiation, two deep levels at 0.98 eV (EP1) and 1.44 eV (EP2) are observed in all the samples irradiated at 116-400 keV, while two additional deep levels (EP3 and EP4) are observed only in the samples irradiated at 400 keV.more » After annealing at 950 degree sign C, these centers are annealed out, and the HK4 (E{sub V}+1.44 eV) concentration is increased. By the electron irradiation at more than 160 keV followed by annealing at 950 degree sign C, three deep levels are always observed at 0.30 eV (UK1), 0.58 eV (UK2), and 1.44 eV (HK4). These centers may be defect complexes including carbon displacement-related defects. All the centers except for the D center are reduced to below the detection limit (1-3x10{sup 11} cm{sup -3}) by annealing at 1550 degree sign C for 30 min.« less

Cleavage of bovine adenovirus type 3 non-structural 100K protein by protease is required for nuclear localization in infected cells but is not essential for virus replication.

PubMed

Makadiya, Nirajkumar; Gaba, Amit; Tikoo, Suresh K

2015-09-01

The L6 region of bovine adenovirus type 3 (BAdV-3) encodes a non-structural protein named 100K. Rabbit antiserum raised against BAdV-3 100K recognized a protein of 130 kDa at 12-24 h and proteins of 130, 100, 95 and 15 kDa at 36-48 h after BAdV-3 infection. The 100K species localized to the nucleus and the cytoplasm of BAdV-3-infected cells. In contrast, 100K localized predominantly to the cytoplasm of the transfected cells. However, BAdV-3 infection of cells transfected with 100K-enhanced yellow fluorescent protein-expressing plasmid detected fluorescent protein in the nucleus of the cells, suggesting that other viral proteins may be required for the nuclear localization of 100K. Interaction of BAdV-3 100K with BAdV-3 33K protein did not alter the cytoplasmic localization of 100K. However, co-expression of BAdV-3 100K and BAdV-3 protease localized 100K to the nucleolus of the transfected cells. Subsequent analysis suggested that BAdV-3 protease cleaves 100K at two identified potential protease cleavage sites (aa 740-745 and 781-786) in transfected or BAdV-3-infected cells. The cleaved C terminus (107 aa) was localized to the nucleolus of the transfected cells. Further analysis suggested that the cleaved C terminus contains a bipartite nuclear localization signal and utilizes import receptor importin-α3 of the classical importin-α/β transport pathway for nuclear transport. Successful isolation of recombinant BAdV-3 expressing mutant 100K (substitution of alanine for glycine in the potential protease cleavage site) suggested that cytoplasmic cleavage of BAdV-3 100K by adenoviral protease is not essential for virus replication.

Arsenate biotransformation by Microcystis aeruginosa under different nitrogen and phosphorus levels.

PubMed

Che, Feifei; Du, Miaomiao; Yan, Changzhou

2018-04-01

The arsenate (As(V)) biotransformation by Microcystis aeruginosa in a medium with different concentrations of nitrogen (N) and phosphorus (P) has been studied under laboratory conditions. When 15μg/L As(V) was added, N and P in the medium showed effective regulation on arsenic (As) metabolism in M. aeruginosa, resulting in significant differences in the algal growth among different N and P treatments. Under 0.2mg/L P treatment, increases in N concentration (4-20mg/L) significantly stimulated the cell growth and therefore indirectly enhanced the production of dimethylarsinic acid (DMA), the main As metabolite, accounting for 71%-79% of the total As in the medium. Meanwhile, 10-20mg/L N treatments accelerated the ability of As metabolization by M. aeruginosa, leading to higher contents of DMA per cell. However, As(V) uptake by M. aeruginosa was significantly impeded by 0.5-1.0mg/L P treatment, resulting in smaller rates of As transformation in M. aeruginosa as well as lower contents of As metabolites in the medium. Our data demonstrated that As(V) transformation by M. aeruginosa was significantly accelerated by increasing N levels, while it was inhibited by increasing P levels. Overall, both P and N play key roles in As(V) biotransformation processes. Copyright © 2017. Published by Elsevier B.V.

Study of the Effects of Ultrasonic Waves on the Reproductive Integrity of Mammalian Cells Cultured in Vitro

NASA Technical Reports Server (NTRS)

Martins, B. I.

1971-01-01

The effects of monochromatic ultrasonic waves of 0.1, 0.5, 1.0, 2.0 and, 3.3 MHz frequency on the colony-forming ability of mammalian cells (M3-1,V79, Chang's and T-1) cultured in vitro have been studied to determine the nature of the action of ultrasonic energy on biological systems at the cellular level. The combined effect of ultrasound and X-rays has also been studied. It is concluded: (1) Ultrasonic irradiation causes both lethal and sublethal damage. (2) There is a threshold dose rate for lethal effects. (3) The effectiveness of ultrasonic waves in causing cell death probably depends on the frequency and the amplitude of the waves for a given cell line, indicating a possible resonance phenomenon.

Cytotoxic, genotoxic and mutagenic evaluation of surface waters from a coal exploration region.

PubMed

Porta, Cynthia Silva; Dos Santos, Débora Lemes; Bernardes, Hélio Vieira; Bellagamba, Bruno Corrêa; Duarte, Anaí; Dias, Johnny Ferraz; da Silva, Fernanda Rabaioli; Lehmann, Mauricio; da Silva, Juliana; Dihl, Rafael Rodrigues

2017-04-01

Coal mining generates a considerable amount of waste, which is disposed of in piles or dams near mining sites. As a result, leachates may reach rivers and streams, promoting the wide dispersion of contaminants in solution and as particulate matter. The present study evaluated the cytotoxic, genotoxic, and mutagenic action of surface waters collected around a thermoelectric power plant and the largest mining area in Brazil (Candiota). Four sites in Candiota stream were selected, and samples were collected in winter and summer. Water samples were analyzed using the comet and CBMN assays in V79 and HepG2 cells. Furthermore, genotoxicity of water samples was evaluated in vivo using the SMART in Drosophila melanogaster. In addition, polycyclic aromatic hydrocarbons and inorganic elements were quantified. The results indicate that water samples exhibited no genotoxic and mutagenic activities, whether in vitro or in vivo. On the other hand, surface water samples collected in sites near the power plant in both summer and winter inhibited cell proliferation and induced increased frequencies of V79 cell death, apoptosis, and necrosis. The cytotoxicity observed may be associated with the presence of higher concentration of inorganic elements, especially aluminum, silicon, sulfur, titanium and zinc at sites 1 and 2 in the stream, as well as with the complex mixture present in the coal, in both seasons. Therefore, the results obtained point to the toxicity potential of water samples with the influence of coal mining and combustion processes and the possible adverse effects on the health of exposed organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Roll type conducting polymer legs for rigid-flexible thermoelectric generator

NASA Astrophysics Data System (ADS)

Park, Teahoon; Lim, Hanwhuy; Hwang, Jong Un; Na, Jongbeom; Lee, Hyunki; Kim, Eunkyoung

2017-07-01

A roll-type conducting polymer film was explored as a flexible organic p-type thermoelectric leg using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with tosylate. The PEDOT films were prepared through solution casting polymerization and rolled up for a roll-type leg. Due to the high flexibility, the roll-type PEDOT leg enabled easy contact to both top and bottom electrodes. Simulation on the dynamic heat transfer and convective cooling for a vertically roosted rod- and roll-type PEDOT leg showed that the temperature difference (ΔT) between the hot and cold sides of the leg was much higher in the roll than that of the rod. The PEDOT legs were integrated with n-type Bi2Te3 blocks, to give a 36-couple rigid-flexible thermoelectric generator (RF-TEG). The maximum output voltage from the 36-couple RF-TEG under a ΔT of 7.9 K was determined as 36.7 mV along with a high output power of 115 nW. A wearable RF-TEG was prepared upon the combination of the 36-couple RF-TEG with an arm warmer, to afford an output voltage of 10.6 mV, which was generated constantly and steadily from human wrist heat.

Identification of cancer initiating cells in K-Ras driven lung adenocarcinoma.

PubMed

Mainardi, Sara; Mijimolle, Nieves; Francoz, Sarah; Vicente-Dueñas, Carolina; Sánchez-García, Isidro; Barbacid, Mariano

2014-01-07

Ubiquitous expression of a resident K-Ras(G12V) oncogene in adult mice revealed that most tissues are resistant to K-Ras oncogenic signals. Indeed, K-Ras(G12V) expression only induced overt tumors in lungs. To identify these transformation-permissive cells, we induced K-Ras(G12V) expression in a very limited number of adult lung cells (0.2%) and monitored their fate by X-Gal staining, a surrogate marker coexpressed with the K-Ras(G12V) oncoprotein. Four weeks later, 30% of these cells had proliferated to form small clusters. However, only SPC(+) alveolar type II (ATII) cells were able to form hyperplastic lesions, some of which progressed to adenomas and adenocarcinomas. In contrast, induction of K-Ras(G12V) expression in lung cells by intratracheal infection with adenoviral-Cre particles generated hyperplasias in all regions except the proximal airways. Bronchiolar and bronchioalveolar duct junction hyperplasias were primarily made of CC10(+) Clara cells. Some of them progressed to form benign adenomas. However, only alveolar hyperplasias, exclusively made up of SPC(+) ATII cells, progressed to yield malignant adenocarcinomas. Adenoviral infection induced inflammatory infiltrates primarily made of T and B cells. This inflammatory response was essential for the development of K-Ras(G12V)-driven bronchiolar hyperplasias and adenomas, but not for the generation of SPC(+) ATII lesions. Finally, activation of K-Ras(G12V) during embryonic development under the control of a Sca1 promoter yielded CC10(+), but not SPC(+), hyperplasias, and adenomas. These results, taken together, illustrate that different types of lung cells can generate benign lesions in response to K-Ras oncogenic signals. However, in adult mice, only SPC(+) ATII cells were able to yield malignant adenocarcinomas.

Variability and repertoire size of T-cell receptor V alpha gene segments.

PubMed

Becker, D M; Pattern, P; Chien, Y; Yokota, T; Eshhar, Z; Giedlin, M; Gascoigne, N R; Goodnow, C; Wolf, R; Arai, K

The immune system of higher organisms is composed largely of two distinct cell types, B lymphocytes and T lymphocytes, each of which is independently capable of recognizing an enormous number of distinct entities through their antigen receptors; surface immunoglobulin in the case of the former, and the T-cell receptor (TCR) in the case of the latter. In both cell types, the genes encoding the antigen receptors consist of multiple gene segments which recombine during maturation to produce many possible peptides. One striking difference between B- and T-cell recognition that has not yet been resolved by the structural data is the fact that T cells generally require a major histocompatibility determinant together with an antigen whereas, in most cases, antibodies recognize antigen alone. Recently, we and others have found that a series of TCR V beta gene sequences show conservation of many of the same residues that are conserved between heavy- and light-chain immunoglobulin V regions, and these V beta sequences are predicted to have an immunoglobulin-like secondary structure. To extend these studies, we have isolated and sequenced eight additional alpha-chain complementary cDNA clones and compared them with published sequences. Analyses of these sequences, reported here, indicate that V alpha regions have many of the characteristics of V beta gene segments but differ in that they almost always occur as cross-hybridizing gene families. We conclude that there may be very different selective pressures operating on V alpha and V beta sequences and that the V alpha repertoire may be considerably larger than that of V beta.

3D Nitrogen, Sulfur-Codoped Carbon Nanomaterial-Supported Cobalt Oxides with Polyhedron-Like Particles Grafted onto Graphene Layers as Highly Active Bicatalysts for Oxygen-Evolving Reactions.

PubMed

Huang, Xiaobo; Wang, Jianqiang; Bao, Hongliang; Zhang, Xiangkun; Huang, Yongmin

2018-02-28

The extensive research and developments of highly efficient oxygen electrode electrocatalysts to get rid of the kinetic barriers for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are very important in energy conversion and storage devices. Especially, exploring nonprecious metal alternatives to replace traditional noble metal catalysts with high cost and poor durability is the paramount mission. In this paper, we utilize property-flexible ZIF-67 and sulfur-functionalized graphene oxide to obtain a cobalt, nitrogen, and sulfur codoped nanomaterial with 3D hierarchical porous structures, owing to their rich dopant species and good conductivity. The crosslinked structures of polyhedron particles throughout the whole carbon framework speeds up the mass transportation and charge-delivery processes during oxygen-evolving reactions. Also, by exploring the location and coordination type of sulfur dopants, we emphasize the effects of sulfone and sulfide functional groups anchored into the graphitic structure on enhancing the catalytic abilities for ORR and OER. To note, compared to the noble metal electrocatalysts, the best-performing CoO@Co 3 O 4 /NSG-650 (0.79 V) is 40 mV less active than the commercial Pt/C catalyst (0.83 V) for ORR and merely 10 mV behind IrO 2 (1.68 V) for OER. Besides, the metric between ORR and OER difference for CoO@Co 3 O 4 /NSG-650 to evaluate its overall electrocatalytic activity is 0.90 V, surpassing 290 and 430 mV over Pt/C (1.19 V) and IrO 2 (1.33 V). Comprehensively, the as-prepared CoO@Co 3 O 4 /NSG-650 indicates excellent bifunctional catalytic activities for ORR and OER, which shows great potential for replacing noble metal catalysts in the application of fuel cells and metal-air batteries.

CD4 Receptor is a Key Determinant of Divergent HIV-1 Sensing by Plasmacytoid Dendritic Cells

PubMed Central

Wilen, Craig; Gopal, Ramya; Huq, Rumana; Wu, Vernon; Sunseri, Nicole; Bhardwaj, Nina

2016-01-01

Plasmacytoid dendritic cells (pDC) are innate immune cells that sense viral nucleic acids through endosomal Toll-like receptor (TLR) 7/9 to produce type I interferon (IFN) and to differentiate into potent antigen presenting cells (APC). Engagement of TLR7/9 in early endosomes appears to trigger the IRF7 pathway for IFN production whereas engagement in lysosomes seems to trigger the NF-κB pathway for maturation into APC. We showed previously that HIV-1 (HIV) localizes predominantly to early endosomes, not lysosomes, and mainly stimulate IRF7 rather than NF-κB signaling pathways in pDC. This divergent signaling may contribute to disease progression through production of pro-apoptotic and pro-inflammatory IFN and inadequate maturation of pDCs. We now demonstrate that HIV virions may be re-directed to lysosomes for NF-κB signaling by either pseudotyping HIV with influenza hemagglutinin envelope or modification of CD4 mediated-intracellular trafficking. These data suggest that HIV envelope-CD4 receptor interactions drive pDC activation toward an immature IFN producing phenotype rather than differentiation into a mature dendritic cell phenotype. PMID:27082754

Human parvovirus B19: a mechanistic overview of infection and DNA replication

PubMed Central

Luo, Yong; Qiu, Jianming

2015-01-01

Human parvovirus B19 (B19V) is a human pathogen that belongs to genus Erythroparvovirus of the Parvoviridae family, which is composed of a group of small DNA viruses with a linear single-stranded DNA genome. B19V mainly infects human erythroid progenitor cells and causes mild to severe hematological disorders in patients. However, recent clinical studies indicate that B19V also infects nonerythroid lineage cells, such as myocardial endothelial cells, and may be associated with other disease outcomes. Several cell culture systems, including permissive and semipermissive erythroid lineage cells, nonpermissive human embryonic kidney 293 cells and recently reported myocardial endothelial cells, have been used to study the mechanisms underlying B19V infection and B19V DNA replication. This review aims to summarize recent advances in B19V studies with a focus on the mechanisms of B19V tropism specific to different cell types and the cellular pathways involved in B19V DNA replication including cellular signaling transduction and cell cycle arrest. PMID:26097496

The improved efficiency of low molecular weight organic solar cells doped with a Cu(I) triplet material

NASA Astrophysics Data System (ADS)

Su, Bin; Gao, Lin; Li, Xiuying; Che, Guangbo; Zhu, Enwei; Wang, Bo; Yan, Yongsheng

2016-08-01

We developed a method to improve the performance of the copper phthalocyanine (CuPc)/fullerene (C60) organic solar cells (OSCs) by doping CuPc with a long triplet lifetime material. By doping [Cu(bis[2-(diphenylphosphino)phenyl]ether)(benzo[i]dipyrido[3,2-a:2',3'-c]phenazine)]BF4 (CuDB) into CuPc, the enhanced short-circuit current density ( J SC) of 6.213 mA/cm2, open-circuit voltage ( V OC) of 0.39 V and a peak power conversion efficiency (PCE) of 0.92% compared to 0.79% of the standard CuPc/C60 OSCs are achieved under 1 sun AM 1.5 G illumination at an intensity of 100 mW/cm2. The performance improvement is mainly attributed to the long triplet lifetime of CuDB (τ = 70.05 μs) which leads to more effective exciton dissociation.

No evidence for adaptation of current egg drop syndrome 1976 viruses to chickens.

PubMed

Tsukamoto, K; Kuwabara, M; Kaneko, M; Mase, M; Imai, K

2004-01-01

In order to determine whether the current field strains of egg drop syndrome (EDS) 1976 viruses adapt to chickens, we compared the growth efficiency of three Japanese field strains (PA-1/79, AWI/98, Gifu/01) in chicken and duck embryo liver cells. The growth efficiency in chicken or duck embryo liver cells was almost similar in these strains. The fiber protein may carry the type-specific antigen and the hemagglutination activity, and hexon protein may contain the subgroup-specific antigenic determinants. Therefore, the fiber head and hexon loop 1 DNA domain sequences of the six Japanese field strains UPA-1/79, ME/80, 44/81, Kyoto/91, AWI/98, Gifu/01) were compared, but these DNA domains were identical among the six field strains. Our data suggested that the EDS virus was maintained without discernible changes for the last two decades in the field.

Layered transition metal thiophosphates /MPX3/ as photoelectrodes in photoelectrochemical cells

NASA Technical Reports Server (NTRS)

Byvik, C. E.; Smith, B. T.; Reichman, B.

1982-01-01

Layered crystals of the transition metal thiophosphates were synthesized and characterized for use as photoelectrodes in photoelectrochemical cells. Crystals incorporating tin and manganese show n-type response while those with iron and nickel show p-type response. These materials have a measured indirect bandgap of about 2.1 eV. They show ability to photoelectrolyze water in acid solutions with onset potentials which change in a Nernstian way as the PH of the solution changes. The onset potential is near zero volts versus a saturated calomel electrode at pH 2. At n-type crystals, oxygen could be evolved upon irradiation at underpotentials of 850 mV and at p-type crystals, hydrogen could be evolved at underpotentials of 400 mV, indicating a net gain in energy conversion. All crystals were unstable in basic solution. Liquid junction photovoltaic cells in iodide-triiodide acid solution using these layered materials were also constructed and found to have low efficiences.

Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca2+ Channels

PubMed Central

Pellegrini, Chiara; Lecci, Sandro; Lüthi, Anita; Astori, Simone

2016-01-01

Study Objectives: Low-threshold voltage-gated T-type Ca2+ channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). Methods: We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. Results: CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca2+ currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10–15 Hz), which was accompanied by an increase in the δ band (1–4 Hz). Conclusions: Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms. Citation: Pellegrini C, Lecci S, Lüthi A, Astori S. Suppression of sleep spindle rhythmogenesis in mice with deletion of Cav3.2 and Cav3.3 T-type Ca2+ channels. SLEEP 2016;39(4):875–885. PMID:26612388

A polymer tandem solar cell with 10.6% power conversion efficiency.

PubMed

You, Jingbi; Dou, Letian; Yoshimura, Ken; Kato, Takehito; Ohya, Kenichiro; Moriarty, Tom; Emery, Keith; Chen, Chun-Chao; Gao, Jing; Li, Gang; Yang, Yang

2013-01-01

An effective way to improve polymer solar cell efficiency is to use a tandem structure, as a broader part of the spectrum of solar radiation is used and the thermalization loss of photon energy is minimized. In the past, the lack of high-performance low-bandgap polymers was the major limiting factor for achieving high-performance tandem solar cell. Here we report the development of a high-performance low bandgap polymer (bandgap <1.4 eV), poly[2,7-(5,5-bis-(3,7-dimethyloctyl)-5H-dithieno[3,2-b:2',3'-d]pyran)-alt-4,7-(5,6-difluoro-2,1,3-benzothia diazole)] with a bandgap of 1.38 eV, high mobility, deep highest occupied molecular orbital. As a result, a single-junction device shows high external quantum efficiency of >60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions (25 °C, 1,000 Wm(-2), IEC 60904-3 global), which is the first certified polymer solar cell efficiency over 10%.

A polymer tandem solar cell with 10.6% power conversion efficiency

PubMed Central

You, Jingbi; Dou, Letian; Yoshimura, Ken; Kato, Takehito; Ohya, Kenichiro; Moriarty, Tom; Emery, Keith; Chen, Chun-Chao; Gao, Jing; Li, Gang; Yang, Yang

2013-01-01

An effective way to improve polymer solar cell efficiency is to use a tandem structure, as a broader part of the spectrum of solar radiation is used and the thermalization loss of photon energy is minimized. In the past, the lack of high-performance low-bandgap polymers was the major limiting factor for achieving high-performance tandem solar cell. Here we report the development of a high-performance low bandgap polymer (bandgap <1.4 eV), poly[2,7-(5,5-bis-(3,7-dimethyloctyl)-5H-dithieno[3,2-b:2′,3′-d]pyran)-alt-4,7-(5,6-difluoro-2,1,3-benzothia diazole)] with a bandgap of 1.38 eV, high mobility, deep highest occupied molecular orbital. As a result, a single-junction device shows high external quantum efficiency of >60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions (25 °C, 1,000 Wm−2, IEC 60904-3 global), which is the first certified polymer solar cell efficiency over 10%. PMID:23385590

Hydrogen in La2MgNi9D13: the role of magnesium.

PubMed

Denys, Roman V; Yartys, Volodymyr A; Webb, Colin J

2012-04-02

Reversible hydrogen storage capacity of the La(3-x)Mg(x)Ni(9) alloys, charged by gaseous hydrogen or by electrochemical methods, reaches its maximum at composition La(2)MgNi(9). As (La,Mg)Ni(3-3.5) alloys are the materials used in advanced metal hydride electrodes in Ni-MH batteries, this raises interest in the study of the structure-properties interrelation in the system La(2)MgNi(9)-H(2) (D(2)). In the present work, this system has been investigated by use of in situ synchrotron X-ray and neutron powder diffraction in H(2)/D(2) gas and by performing pressure-composition-temperature measurements. The saturated La(2)MgNi(9)D(13.1) hydride forms via an isotropic expansion and crystallizes with a trigonal unit cell (space group R3m (No.166); a = 5.4151(1) Å; c = 26.584(2) Å; V = 675.10(6) Å(3)). The studied hybrid structure is composed of a stacking of two layers resembling existing intermetallic compounds LaNi(5) (CaCu(5) type) and LaMgNi(4) (Laves type). These are occupied by D to form LaNi(5)D(5.2) and LaMgNi(4)D(7.9). The LaNi(5)D(5.2) slab has a typical structure observed for all reported LaNi(5)-containing hybrid structures of the AB(5) + Laves phase types. However, the Laves type slab LaMgNi(4)D(7.9) is different from the characterized individual LaMgNi(4)D(4.85) hydride. This results from the filling of a greater variety of interstitial sites in the La(2)MgNi(9)D(13)/LaMgNi(4)D(7.9), including MgNi(2), Ni(4), (La/Mg)(2)Ni(2), and (La/Mg)Ni(3), in contrast with individual LaMgNi(4)D(4.85) where only La(2)MgNi(2) and Ni(4) interstitials are occupied. Despite a random distribution of La and Mg in the structure, a local hydrogen ordering takes place with H atoms favoring occupation of two Mg-surrounded sites, triangles MgNi(2) and tetrahedra LaMgNi(2). A directional bonding between Ni, Mg, and hydrogen is observed and is manifested by a formation of the NiH(4) tetrahedra and MgH(6) octahedra, which are connected to each other by sharing H vertexes to form a spatial framework.

Regulation of L-type CaV1.3 channel activity and insulin secretion by the cGMP-PKG signaling pathway

PubMed Central

Sandoval, Alejandro; Duran, Paz; Gandini, María A.; Andrade, Arturo; Almanza, Angélica; Kaja, Simon; Felix, Ricardo

2018-01-01

cGMP is a second messenger widely used in the nervous system and other tissues. One of the major effectors for cGMP is the serine/threonine protein kinase, cGMP-dependent protein kinase (PKG), which catalyzes the phosphorylation of a variety of proteins including ion channels. Previously, it has been shown that the cGMP-PKG signaling pathway inhibits Ca2+ currents in rat vestibular hair cells and chromaffin cells. This current allegedly flow through voltage-gated CaV1.3L-type Ca2+ channels, and is important for controlling vestibular hair cell sensory function and catecholamine secretion, respectively. Here, we show that native L-type channels in the insulin-secreting RIN-m5F cell line, and recombinant CaV1.3 channels heterologously expressed in HEK-293 cells, are regulatory targets of the cGMP-PKG signaling cascade. Our results indicate that the CaVα1 ion-conducting subunit of the CaV1.3 channels is highly expressed in RIN-m5F cells and that the application of 8-Br-cGMP, a membrane-permeable analogue of cGMP, significantly inhibits Ca2+ macroscopic currents and impair insulin release stimulated with high K+. In addition, KT-5823, a specific inhibitor of PKG, prevents the current inhibition generated by 8-Br-cGMP in the heterologous expression system. Interestingly, mutating the putative phosphorylation sites to residues resistant to phosphorylation showed that the relevant PKG sites for CaV1.3 L-type channel regulation centers on two amino acid residues, Ser793 and Ser860, located in the intracellular loop connecting the II and III repeats of the CaVα1 pore-forming subunit of the channel. These findings unveil a novel mechanism for how the cGMP-PKG signaling pathway may regulate CaV1.3 channels and contribute to regulate insulin secretion. PMID:28807144

Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

NASA Technical Reports Server (NTRS)

Alkasab, K. A.; Abdul-Aziz, A.

1991-01-01

The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

Accession Gaming Model (AGAM).

DTIC Science & Technology

1980-08-01

k D-A009 160 NAVY PERSONNEL RESEARCH AND DEVELOPMENT CENTER SAN 0--ETC F/6 5/9 ACCESSION GAMING MODEL (AGAM).(U) UA 80 A WHISNAN, Y YEN, M...RECIPIENT’SCATALOG NUMBER NPRDC-TR_8 - vA - c I _ _ _ _ _ _ _ *:TITLE (and Suabitle) S. TYPE OF REPORT& PERIOD COVERED /ACCESSION GAMING MODEL (AG AM) ’C Final FY79 S...billet, trained personnel, and untrained personnel requirements, and the development of an Accession Gaming Model (AGAM), an optimization model that

Biological effectiveness of nuclear fragments produced by high-energy protons interacting in tissues near the bone- soft tissue interface

NASA Astrophysics Data System (ADS)

Shavers, Mark Randall

1999-12-01

High-energy protons in the galactic cosmic rays (GCR)-or generated by nuclear interactions of GCR heavy-ions with material-are capable of penetrating great thicknesses of shielding to irradiate humans in spacecraft or in lunar or Martian habitats. As protons interact with the nuclei of the elemental constituents of soft tissue and bone, low energy nuclei-target fragments-are emitted into the cells responsible for bone development and maintenance and for hematopoiesis. Leukemogenesis is the principal endpoint of concern because it is the most likely deleterious effect, and it has a short latency period and comparatively low survival rate, although other myelo- proliferative disorders and osteosarcoma also may be induced. A one-dimensional proton-target fragment transport model was used to calculate the energy spectra of fragments produced in bone and soft tissue, and present in marrow cavities at distances from a bone interface. In terms of dose equivalent, the target fragments are as significant as the incident protons. An average radiation quality factor was found to be between 1.8 and 2.6. Biological response to the highly non- uniform energy deposition of the target fragments is such that an alternative approach to conventional predictive risk assessment is needed. Alternative procedures are presented. In vitro cell response and relative biological effectiveness were calculated from the radial dose distribution of each fragment produced by 1-GeV protons using parameters of a modified Ion-Gamma- Kill (IGK) model of radiation action. The modelled endpoints were survival of C3H10t 1/2 and V79 cells, neoplastic transformation of C3H10t1/2 cells, and mutation of the X-linked hypoxanthine phosphoribosyltransferase (HPRT) locus in V79 cells. The dose equivalent and cell responses increased by 10% or less near the interface. Since RBE increases with decreasing dose in the IGK model, comparisons with quality factors were made at dose levels 0.01 <= D [Gy] <= 2. Applying average quality factors derived herein to GCR exposures results in a <= 5% increase of in average quality. Calculated RBEs indicate that accepted quality factors for high-energy protons may be too low due to the relatively high effectiveness of the low-charged target fragments. Derived RBEs for target fragments increase the calculated biological effectiveness of GCR by 20% to 180%.

The Growth of InGaAsN for High Efficiency Solar Cells by Metalorganic Chemical Vapor Deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

ALLERMAN,ANDREW A.; BANKS,JAMES C.; GEE,JAMES M.

1999-09-16

InGaAsN alloys are a promising material for increasing the efficiency of multi-junction solar cells now used for satellite power systems. However, the growth of these dilute N containing alloys has been challenging with further improvements in material quality needed before the solar cell higher efficiencies are realized. Nitrogen/V ratios exceeding 0.981 resulted in lower N incorporation and poor surface morphologies. The growth rate was found to depend on not only the total group III transport for a fixed N/V ratio but also on the N/V ratio. Carbon tetrachloride and dimethylzinc were effective for p-type doping. Disilane was not an effectivemore » n-type dopant while SiCl4 did result in n-type material but only a narrow range of electron concentrations (2-5e17cm{sup -3}) were achieved.« less

Distribution and ultrastructural characteristics of dark cells in squamous metaplasias of the respiratory tract epithelium.

PubMed Central

Klein-Szanto, A. J.; Nettesheim, P.; Pine, A.; Martin, D.

1981-01-01

Dark epithelial basal cells were found in both carcinogen-induced and non-carcinogen-induced squamous metaplasias of the tracheal epithelium. Formaldehyde-induced squamous metaplasias exhibited 4% dark cells in the basal layer. Metaplasias induced by vitamin A deficiency and those induced by dimethylbenz(alpha)anthracene (DMBA) without atypia showed 18--20% basal dark cells. DMBA-induced metaplasias with moderate to severe atypia exhibited 50% basal dark cells. The labeling index of basal cells in metaplastic epithelia, regardless of the inducing agent, was 16--18%, ie, the same as that of the normal esophageal stratified squamous epithelium. The percentage of labeled dark basal cells per total dark cell population was approximately 19% in the non-carcinogen-induced metaplasias and in the DMBA-induced metaplasias without atypia. In the atypical metaplasias induced by DMA this percentage increased to 26. On the basis of ultrastructural observations, five types of dark epithelial cells could be distinguished in the metaplastic epithelia: Type I (ovoid or fusiform dark cell with abundant cytoplasmic filaments, desmosomes, and free ribosomes--dark keratinocyte type); Type II (ovoid or spherical small cell with scant cytoplasm with few organelles--basal respiratory type); Type III (irregular or ovoid, few cytoplasmic filaments and organelles and desmosomes, extremely abundant free ribosomes--dedifferentiated type); Type IV (fusiform or ovoid, large mitochondria, prominent ergastoplasm, secretion droplets--mucous cell type); and type V (irregular shape, organelle remnants, vacuoles, pyknotic nuclei--involutional-cell type). Type I was the predominant cell type in formaldehyde-induced metaplasias and was also commonly seen in DMBA-induced metaplasias without atypia. Type II predominated in metaplasias induced by vitamin A deficiency. Type III was seen in DMBA-induced metaplasias and was the predominant cell type in the atypical epithelial alterations. Type IV cells occurred only in the latter, and Type V cells were occasionally seen in formaldehyde- as well as in DMBA-induced atypical metaplasias. Each type of squamous metaplasia could thus be recognized by a determined numerical distribution of dark cells in the basal layer and a specific pattern of distribution of the ultrastructurally defined dark cell categories. Images Figure 3 Figure 4 Figure 5 Figure 1 Figure 2 Figure 6 Figure 7 PMID:6786102

Pattern of endothelial progenitor cells and apoptotic endothelial cell-derived microparticles in chronic heart failure patients with preserved and reduced left ventricular ejection fraction

PubMed Central

Berezin, Alexander E.; Kremzer, Alexander A.; Martovitskaya, Yulia V.; Berezina, Tatyana A.; Gromenko, Elena A.

2016-01-01

Background Chronic heart failure (HF) remains a leading cause of cardiovascular (CV) mortality and morbidity worldwide. The aim of the study was to investigate whether the pattern of angiogenic endothelial progenitor cells (EPCs) and apoptotic endothelial cell-derived microparticles (EMPs) would be able to differentiate HF with reduced (HFrEF) and preserved (HFpEF) ejection fraction. Methods One hundred sixty four chronic HF subjects met inclusion criteria. Patients with global left ventricular ejection fraction ≥ 50% were categorized as the HFpEF group (n = 79) and those with ≤ 45% as the HFrEF group (n = 85). Therefore, to compare the circulating levels of biological markers 35 control subjects without HF were included in the study. All control individuals were age- and sex-matched chronic HF patients. The serum level of biomarkers was measured at baseline. The flow cytometric technique was used for predictably distinguishing circulating cell subsets depending on expression of CD45, CD34, CD14, Tie-2, and CD309 antigens and determining endothelial cell-derived microparticles. CD31+/annexin V+ was defined as apoptotic endothelial cell-derived MPs, MPs labeled for CD105+ or CD62E+ were determined as MPs produced due to activation of endothelial cells. Results In multivariate logistic regression model T2DM (R2 = 0.26; P = 0.001), obesity (R2 = 0.22; P = 0.001), previous MI (R2 = 0.17; P = 0.012), galectin-3 (R2 = 0.67; P = 0.012), CD31+/annexin V+ EMPs (R2 = 0.11; P = 0.001), NT-proBNP (R2 = 0.11; P = 0.046), CD14+ CD309+ cells (R2 = 0.058; P = 0.001), and CD14+ СD309+ Tie-2+ cells (R2 = 0.044; P = 0.028) were found as independent predictors of HFpEF. Using multivariate Cox-regression analysis adjusted etiology (previous myocardial infarction), cardiovascular risk factors (obesity, type 2 diabetes mellitus) we found that NT-proBNP (OR 1.08; 95% CI = 1.03–1.12; P = 0.001) and CD31+/annexin V+ EMPs to CD14+ CD309+ cell ratio (OR 1.06; 95% CI = 1.02–1.11; P = 0.02) were independent predictors for HFpEF. Conclusion We found that CD31+/annexin V+ EMPs to CD14+ CD309+ cell ratio added to NT-proBNP, clinical data, and cardiovascular risk factors has exhibited the best discriminate value and higher reliability to predict HFpEF compared with NT-proBNP and clinical data/cardiovascular risk factors alone. PMID:26981573

Establishment of a novel feline leukemia virus (FeLV)-negative B-cell cell line from a cat with B-cell lymphoma.

PubMed

Mochizuki, Hiroyuki; Takahashi, Masashi; Nishigaki, Kazuo; Ide, Tetsuya; Goto-Koshino, Yuko; Watanabe, Shinya; Sato, Hirofumi; Sato, Masahiko; Kotera, Yukiko; Fujino, Yasuhito; Ohno, Koichi; Uchida, Kazuyuki; Tsujimoto, Hajime

2011-04-15

We established a novel feline B-cell line, MS4, from the neoplastic pleural effusion of a cat with cutaneous B-cell lymphoma. Immunophenotype staining of the MS4 cells was positive for CD20, CD79α, and IgA and negative for CD3, CD4, CD5, CD8α, CD18, CD21, CD22, IgM, IgG, Ig light chain, and MHC class II. PCR analysis for immunoglobulin heavy chain gene rearrangements revealed a monoclonal rearrangement, whereas no clonal rearrangement of the T-cell receptor γ gene was detected. Southern blotting with an exogenous feline leukemia virus (FeLV) U3 probe revealed no integration of exogenous FeLV provirus. The MS4 cell line is the first FeLV-negative feline B-cell lymphoma cell line, and may be used to investigate the pathogenesis of spontaneously occurring feline lymphoma and the development of new therapies. Copyright © 2011 Elsevier B.V. All rights reserved.

In vitro, ex vivo and in vivo characterization of PLGA nanoparticles loading pranoprofen for ocular administration.

PubMed

Cañadas, Cristina; Alvarado, Helen; Calpena, Ana C; Silva, Amélia M; Souto, Eliana B; García, Maria L; Abrego, Guadalupe

2016-09-25

Pranoprofen (PF) is a NSAID considered as a safe anti-inflammatory treatment for strabismus and/or cataract surgery. The drug has been formulated in poly (lactic/glycolic) acid (PLGA) nanoparticles (PF-F1NPs with cPF 1.5mg/mL, PF-F2NPs with cPF 1mg/mL) produced by solvent displacement technique and tested the in vitro cytotoxicity, ex vivo corneal permeation, in vivo ocular tolerance and in vivo anti-inflammatory efficacy of PF-F1NPs, PF-F2NPs, in comparison to eye drops conventional dosage form (Oftalar(®), PF 1mg/mL) and free drug solution (PF dissolved in PBS, 1.5mg/mL). The mean particle size of both formulations was around 350nm, with polydispersity index below 0.1, and a net negative charge of -7.41mV and -8.5mV for PF-F1NPs and PF-F2NPs, respectively. Y-79 human retinoblastoma cell line was used to evaluate the cytotoxicity of PF-F1NPs and PF-F2NPs, which were compared to blank NPs and free drug solution (PF dissolved in PBS, 1.5mg/mL). Concentrations up to 75μg/mL exhibited no toxicity to Y-79 cells, whereas at 150μg/mL a decrease of about 80% on the cell viability was observed after exposing the cells to PF-F1NPs. When treating the Y-79 cells with concentrations of PF-F2NPs between 1μg/mL to 100μg/mL, the cell viability was similar to control values after 24h and 48h of exposure. An ex vivo corneal permeation study was carried out in New Zealand rabbits. A very similar profile has been observed for the permeation of PF through the cornea when administered as eye drops and as free drug solution, which was kept much lower in comparison to PF-NPs formulations. The permeated amount of PF from the PF-F1NPs was slightly smaller than from PF-F2NPs, attributed to the increase of viscosity of the formulations with the increase of cPVA concentration. New Zealand white rabbits were also used to evaluate the irritancy of PF-F1NPs and PF-F2NPs, which demonstrated to be well-tolerated to the eye (i.e. the mean total score (MTS) was 0). PF-F2NPs exhibited the highest QP (amounts of PF permeated in the cornea) and significantly reduced the ocular edema compared to the tested formulations. The QR (amounts of PF retained in the cornea) of the PF-F1NPs was greater than that obtained for PF-F2NPs. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioactive saponins from the fruits of Aesculus pavia L.

PubMed

Sun, Zhen-Liang; Zhang, Ming; Wu, Ying; Wan, Ai-Hong; Zhang, Rong

2011-10-01

Continued chemical investigation on the fruits of Aesculus pavia L. resulted in theisolation and identification of two new oleanolic acid saponins, namely vaccaroside A (1) andvaccaroside B (2). The isolated furostanol saponins were evaluated for cytotoxic activity againsthuman normal amniotic and human lung carcinoma cell lines using neutral red and MTT assays.In vitro experiments showed significant cytotoxicity in a dose dependent manner with IC₅₀ valuesin the range of 27.80-79.02 μM. Copyright © 2011 Elsevier B.V. All rights reserved.

Intracellular Ca2+ regulation by the leech giant glial cell.

PubMed

Nett, W; Deitmer, J W

1998-02-15

1. We have measured the intracellular Ca2+ concentration, [Ca2+]i, and the intracellular Na+ concentration, [Na+]i, with the fluorescent dyes fura-2 (for Ca2+) and SBFI (for Na+) in situ in giant glial cells of the central nervous system of the leech Hirudo medicinalis. 2. The basal [Ca2+]i was 79 +/- 35 nM (n = 27) in cells voltage clamped at -70 to -80 mV, and 75 +/- 29 nM (mean +/- S.D., n = 82) in unclamped cells at a mean membrane potential of -67 +/- 6 mV. 3. Removal of external Na+ evoked a small reversible [Ca2+]i increase of 29 +/- 21 nM (n = 27) in cells voltage clamped at -70 to -80 mV, and of 35 +/- 18 nM (n = 37) in unclamped cells. This [Ca2+]i increase, and the time constant of the subsequent [Ca2+]i recovery after Na+ re-addition, did not change significantly with the holding potential between -110 and -60 mV. 4. The basal [Na+]i was 5.6 +/- 1.3 mM (n = 18). Increasing [Na+]i by inhibiting the Na+-K+ pump with 100 microM ouabain had no effect on the [Ca2+]i rise upon removal of external Na+. 5. The time course of recovery from a [Ca2+]i load mediated by voltage-dependent Ca2+ influx during depolarization in high K+ was unaffected by the removal of external Na+. 6. Cyclopiazonic acid (10 muM), an inhibitor of the endoplasmic reticulum Ca2+-ATPase, caused a transient increase in [Ca2+]i of 28 +/- 11 nM (n = 5), and significantly slowed the recovery from imposed [Ca2+]i loads. 7. Iontophoretic injection of orthovanadate, an inhibitor of P-type ATPases including the plasma membrane Ca2+-ATPase, caused a persistent increase in the basal [Ca2+]i of 163 +/- 101 nM (n = 5) in standard saline, and of 427 +/- 338 nM in Na+-free saline (n = 5). Vanadate injection significantly slowed the recovery from [Ca2+]i loads. Removal of external Na+ during vanadate injection induced an additional, reversible [Ca2+]i increase of 254 +/- 64 nM (n = 3). 8. The results suggest that the low basal [Ca2+]i in these glial cells is predominantly maintained by a Ca2+-ATPase in the plasma membrane. This ATPase is also the main Ca2+ extruder after an intracellular Ca2+ load, while intracellular stores appear to contribute little to this recovery. A Na+-Ca2+ exchanger seems to play a minor role in the maintenance of basal [Ca2+]i in these cells, but becomes prominent when the plasma membrane Ca2+-ATPase is blocked.

Mutations in yeast proliferating cell nuclear antigen define distinct sites for interaction with DNA polymerase delta and DNA polymerase epsilon.

PubMed Central

Eissenberg, J C; Ayyagari, R; Gomes, X V; Burgers, P M

1997-01-01

The importance of the interdomain connector loop and of the carboxy-terminal domain of Saccharomyces cerevisiae proliferating cell nuclear antigen (PCNA) for functional interaction with DNA polymerases delta (Poldelta) and epsilon (Pol epsilon) was investigated by site-directed mutagenesis. Two alleles, pol30-79 (IL126,128AA) in the interdomain connector loop and pol30-90 (PK252,253AA) near the carboxy terminus, caused growth defects and elevated sensitivity to DNA-damaging agents. These two mutants also had elevated rates of spontaneous mutations. The mutator phenotype of pol30-90 was due to partially defective mismatch repair in the mutant. In vitro, the mutant PCNAs showed defects in DNA synthesis. Interestingly, the pol30-79 mutant PCNA (pcna-79) was most defective in replication with Poldelta, whereas pcna-90 was defective in replication with Pol epsilon. Protein-protein interaction studies showed that pcna-79 and pcna-90 failed to interact with Pol delta and Pol epsilon, respectively. In addition, pcna-90 was defective in interaction with the FEN-1 endo-exonuclease (RTH1 product). A loss of interaction between pcna-79 and the smallest subunit of Poldelta, the POL32 gene product, implicates this interaction in the observed defect with the polymerase. Neither PCNA mutant showed a defect in the interaction with replication factor C or in loading by this complex. Processivity of DNA synthesis by the mutant holoenzyme containing pcna-79 was unaffected on poly(dA) x oligo(dT) but was dramatically reduced on a natural template with secondary structure. A stem-loop structure with a 20-bp stem formed a virtually complete block for the holoenzyme containing pcna-79 but posed only a minor pause site for wild-type holoenzyme, indicating a function of the POL32 gene product in allowing replication past structural blocks. PMID:9343398

Rectification of the water permeability in COS-7 cells at 22, 10 and 0°C.

PubMed

Peckys, Diana B; Kleinhans, F W; Mazur, Peter

2011-01-01

The osmotic and permeability parameters of a cell membrane are essential physico-chemical properties of a cell and particularly important with respect to cell volume changes and the regulation thereof. Here, we report the hydraulic conductivity, L(p), the non-osmotic volume, V(b), and the Arrhenius activation energy, E(a), of mammalian COS-7 cells. The ratio of V(b) to the isotonic cell volume, V(c iso), was 0.29. E(a), the activation energy required for the permeation of water through the cell membrane, was 10,700, and 12,000 cal/mol under hyper- and hypotonic conditions, respectively. Average values for L(p) were calculated from swell/shrink curves by using an integrated equation for L(p). The curves represented the volume changes of 358 individually measured cells, placed into solutions of nonpermeating solutes of 157 or 602 mOsm/kg (at 0, 10 or 22°C) and imaged over time. L(p) estimates for all six combinations of osmolality and temperature were calculated, resulting in values of 0.11, 0.21, and 0.10 µm/min/atm for exosmotic flow and 0.79, 1.73 and 1.87 µm/min/atm for endosmotic flow (at 0, 10 and 22°C, respectively). The unexpected finding of several fold higher L(p) values for endosmotic flow indicates highly asymmetric membrane permeability for water in COS-7. This phenomenon is known as rectification and has mainly been reported for plant cell, but only rarely for animal cells. Although the mechanism underlying the strong rectification found in COS-7 cells is yet unknown, it is a phenomenon of biological interest and has important practical consequences, for instance, in the development of optimal cryopreservation.

Aberrant Splicing Promotes Proteasomal Degradation of L-type CaV1.2 Calcium Channels by Competitive Binding for CaVβ Subunits in Cardiac Hypertrophy.

PubMed

Hu, Zhenyu; Wang, Jiong-Wei; Yu, Dejie; Soon, Jia Lin; de Kleijn, Dominique P V; Foo, Roger; Liao, Ping; Colecraft, Henry M; Soong, Tuck Wah

2016-10-12

Decreased expression and activity of Ca V 1.2 calcium channels has been reported in pressure overload-induced cardiac hypertrophy and heart failure. However, the underlying mechanisms remain unknown. Here we identified in rodents a splice variant of Ca V 1.2 channel, named Ca V 1.2 e21+22 , that contained the pair of mutually exclusive exons 21 and 22. This variant was highly expressed in neonatal hearts. The abundance of this variant was gradually increased by 12.5-folds within 14 days of transverse aortic banding that induced cardiac hypertrophy in adult mouse hearts and was also elevated in left ventricles from patients with dilated cardiomyopathy. Although this variant did not conduct Ca 2+ ions, it reduced the cell-surface expression of wild-type Ca V 1.2 channels and consequently decreased the whole-cell Ca 2+ influx via the Ca V 1.2 channels. In addition, the Ca V 1.2 e21+22 variant interacted with Ca V β subunits significantly more than wild-type Ca V 1.2 channels, and competition of Ca V β subunits by Ca V 1.2 e21+22 consequently enhanced ubiquitination and subsequent proteasomal degradation of the wild-type Ca V 1.2 channels. Our findings show that the resurgence of a specific neonatal splice variant of Ca V 1.2 channels in adult heart under stress may contribute to heart failure.

Loss of a single N-linked glycan allows CD4-independent human immunodeficiency virus type 1 infection by altering the position of the gp120 V1/V2 variable loops.

PubMed

Kolchinsky, P; Kiprilov, E; Bartley, P; Rubinstein, R; Sodroski, J

2001-04-01

The gp120 envelope glycoprotein of primary human immunodeficiency virus type 1 (HIV-1) promotes virus entry by sequentially binding CD4 and the CCR5 chemokine receptor on the target cell. Previously, we adapted a primary HIV-1 isolate, ADA, to replicate in CD4-negative canine cells expressing human CCR5. The gp120 changes responsible for CD4-independent replication were limited to the V2 loop-V1/V2 stem. Here we show that elimination of a single glycosylation site at asparagine 197 in the V1/V2 stem is sufficient for CD4-independent gp120 binding to CCR5 and for HIV-1 entry into CD4-negative cells expressing CCR5. Deletion of the V1/V2 loops also allowed CD4-independent viral entry and gp120 binding to CCR5. The binding of the wild-type ADA gp120 to CCR5 was less dependent upon CD4 at 4 degrees C than at 37 degrees C. In the absence of the V1/V2 loops, neither removal of the N-linked carbohydrate at asparagine 197 nor lowering of the temperature increased the CD4-independent phenotypes. A CCR5-binding conformation of gp120, achieved by CD4 interaction or by modification of temperature, glycosylation, or variable loops, was preferentially recognized by the monoclonal antibody 48d. These results suggest that the CCR5-binding region of gp120 is occluded by the V1/V2 variable loops, the position of which can be modulated by temperature, CD4 binding, or an N-linked glycan in the V1/V2 stem.

Evaluation of various solvent systems for lipid extraction from wet microalgal biomass and its effects on primary metabolites of lipid-extracted biomass.

PubMed

Ansari, Faiz Ahmad; Gupta, Sanjay Kumar; Shriwastav, Amritanshu; Guldhe, Abhishek; Rawat, Ismail; Bux, Faizal

2017-06-01

Microalgae have tremendous potential to grow rapidly, synthesize, and accumulate lipids, proteins, and carbohydrates. The effects of solvent extraction of lipids on other metabolites such as proteins and carbohydrates in lipid-extracted algal (LEA) biomass are crucial aspects of algal biorefinery approach. An effective and economically feasible algae-based oil industry will depend on the selection of suitable solvent/s for lipid extraction, which has minimal effect on metabolites in lipid-extracted algae. In current study, six solvent systems were employed to extract lipids from dry and wet biomass of Scenedesmus obliquus. To explore the biorefinery concept, dichloromethane/methanol (2:1 v/v) was a suitable solvent for dry biomass; it gave 18.75% lipids (dry cell weight) in whole algal biomass, 32.79% proteins, and 24.73% carbohydrates in LEA biomass. In the case of wet biomass, in order to exploit all three metabolites, isopropanol/hexane (2:1 v/v) is an appropriate solvent system which gave 7.8% lipids (dry cell weight) in whole algal biomass, 20.97% proteins, and 22.87% carbohydrates in LEA biomass. Graphical abstract: Lipid extraction from wet microalgal biomass and biorefianry approach.

The Immune Response in Measles: Virus Control, Clearance and Protective Immunity.

PubMed

Griffin, Diane E

2016-10-12

Measles is an acute systemic viral infection with immune system interactions that play essential roles in multiple stages of infection and disease. Measles virus (MeV) infection does not induce type 1 interferons, but leads to production of cytokines and chemokines associated with nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) signaling and activation of the NACHT, LRR and PYD domains-containing protein (NLRP3) inflammasome. This restricted response allows extensive virus replication and spread during a clinically silent latent period of 10-14 days. The first appearance of the disease is a 2-3 day prodrome of fever, runny nose, cough, and conjunctivitis that is followed by a characteristic maculopapular rash that spreads from the face and trunk to the extremities. The rash is a manifestation of the MeV-specific type 1 CD4⁺ and CD8⁺ T cell adaptive immune response with lymphocyte infiltration into tissue sites of MeV replication and coincides with clearance of infectious virus. However, clearance of viral RNA from blood and tissues occurs over weeks to months after resolution of the rash and is associated with a period of immunosuppression. However, during viral RNA clearance, MeV-specific antibody also matures in type and avidity and T cell functions evolve from type 1 to type 2 and 17 responses that promote B cell development. Recovery is associated with sustained levels of neutralizing antibody and life-long protective immunity.

Design and application of ion-implanted polySi passivating contacts for interdigitated back contact c-Si solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Guangtao; Ingenito, Andrea; Hameren, Nienke van

2016-01-18

Ion-implanted passivating contacts based on poly-crystalline silicon (polySi) are enabled by tunneling oxide, optimized, and used to fabricate interdigitated back contact (IBC) solar cells. Both n-type (phosphorous doped) and p-type (boron doped) passivating contacts are fabricated by ion-implantation of intrinsic polySi layers deposited via low-pressure chemical vapor deposition and subsequently annealed. The impact of doping profile on the passivation quality of the polySi doped contacts is studied for both polarities. It was found that an excellent surface passivation could be obtained by confining as much as possible the implanted-and-activated dopants within the polySi layers. The doping profile in the polySimore » was controlled by modifying the polySi thickness, the energy and dose of ion-implantation, and the temperature and time of annealing. An implied open-circuit voltage of 721 mV for n-type and 692 mV for p-type passivating contacts was achieved. Besides the high passivating quality, the developed passivating contacts exhibit reasonable high conductivity (R{sub sh n-type} = 95 Ω/□ and R{sub sh p-type} = 120 Ω/□). An efficiency of 19.2% (V{sub oc} = 673 mV, J{sub sc} = 38.0 mA/cm{sup 2}, FF = 75.2%, and pseudo-FF = 83.2%) was achieved on a front-textured IBC solar cell with polySi passivating contacts as both back surface field and emitter. By improving the front-side passivation, a V{sub OC} of 696 mV was also measured.« less

Melatonin and its precursors in Y79 human retinoblastoma cells: Effect of sodium butyrate

NASA Technical Reports Server (NTRS)

Deng, Mei Hua; Coviella, Ignacio Lopez G.; Lynch, Harry J.; Wurtman, Richard J.

1991-01-01

The release of melatonin and the production of its precursors, S-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells were studied. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for 3 days. This protocol dramatically increased the release of melatonin, and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine (10 micro-M) or L-DOPA (100 micro-M) markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation (e.g. treatment with sodium butyrate) can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 cells. The inhibition of melatonin release by dopamine supports the hypothesis that in these cells, melatonin and dopamine are components of a retinal feedback loop.

Mutant calreticulin-expressing cells induce monocyte hyperreactivity through a paracrine mechanism

PubMed Central

Garbati, Michael R.; Welgan, Catherine A.; Landefeld, Sally H.; Newell, Laura F.; Agarwal, Anupriya; Dunlap, Jennifer B.; Chourasia, Tapan K.; Lee, Hyunjung; Elferich, Johannes; Traer, Elie; Rattray, Rogan; Cascio, Michael J.; Press, Richard D.; Bagby, Grover C.; Tyner, Jeffrey W.; Druker, Brian J.; Dao, Kim-Hien T.

2016-01-01

Mutations in the calreticulin gene (CALR) were recently identified in approximately 70–80% of patients with JAK2-V617F-negative essential thrombocytosis and primary myelofibrosis. All frameshift mutations generate a recurring novel C-terminus. Here we provide evidence that mutant calreticulin does not accumulate efficiently in cells and is abnormally enriched in the nucleus and extracellular space compared to wildtype calreticulin. The main determinant of these findings is the loss of the calcium-binding and KDEL domains. Expression of type I mutant CALR in Ba/F3 cells confers minimal IL-3-independent growth. Interestingly, expression of type I and type II mutant CALR in a non-hematopoietic cell line does not directly activate JAK/STAT signaling compared to JAK2-V617F expression. These results led us to investigate paracrine mechanisms of JAK/STAT activation. Here we show that conditioned media from cells expressing type I mutant CALR exaggerate cytokine production from normal monocytes with or without treatment with a toll-like receptor agonist. These effects are not dependent on the novel C-terminus. These studies offer novel insights into the mechanism of JAK/STAT activation in patients with JAK2-V617F-negative essential thrombocytosis and primary myelofibrosis. PMID:26573090

Accelerated appearance of multiple B cell lymphoma types in NFS/N mice congenic for ecotropic murine leukemia viruses.

PubMed

Hartley, J W; Chattopadhyay, S K; Lander, M R; Taddesse-Heath, L; Naghashfar, Z; Morse, H C; Fredrickson, T N

2000-02-01

Spontaneous lymphomas occur at high frequency in NFS x V+ mice, strains congenic for ecotropic murine leukemia virus (MuLV) proviral genes and expressing virus at high titer. In the present study, a total of 703 NFS x V+ lymphomas were studied by histopathology, immunophenotypic analysis, immunoglobulin heavy chain or T cell receptor beta chain rearrangements, and somatic ecotropic MuLV integrations; 90% of the lymphomas tested were of B cell lineage. Low-grade tumors included small lymphocytic, follicular, and splenic marginal zone lymphomas, while high-grade tumors comprised diffuse large-cell (centroblastic and immunoblastic types), splenic marginal zone, and lymphoblastic lymphomas. Comparison of mice of similar genetic background except for presence (NFS x V+) or absence (NFS x V-) of functional ecotropic MuLV genomes showed that NFS x V-clonal lymphomas developed at about one-half the rate of those occurring in NFS x V+ mice, and most were low-grade B cell lymphomas with extended latent periods. In NFS x V+ mice, clonal outgrowth, defined by Ig gene rearrangements, was associated with acquisition of somatic ecotropic proviral integrations, suggesting that, although generation of B cell clones can be virus independent, ecotropic virus may act to increase the rate of generation of clones and speed their evolution to lymphoma. The mechanism remains undefined, because only rare rearrangements were detected in several cellular loci previously associated with MuLV insertional mutagenesis.

Improved Photometric Characteristics of the Newly Discovered EW-Type System GSC 04370-00206

NASA Astrophysics Data System (ADS)

Breus, V. V.; Andronov, I. L.; Dubovsky, P. A.; Hegedus, T.; Kudzej, I.; Petrik, K.

2010-12-01

We present results of two-color photometric study of the newly discovered EW-type eclipsing binary star GSC 04370-00206 in the field of the intermediate polar MU Cam. CCD V,R observations were obtained in the Astronomical Observatories in Hlohovec, Baja and Kolonica in 2007-2009. Improved photometric elements for the primary minimum were determined: Min.BJD=2454805.75635+0.44264511(27)E. The range of the brightness variations is 13.79-14.13 (V) and 13.07-13.44 (R). The accuracy of the period determination is by a factor of ˜ 7, 000 times better than the one published by the discoverers based on only one night of observations. We report on the night-to-night variability of the shape of the light curve which is interpreted by a presence of spots in the atmosphere of one or both components (O'Connel effect).

A Drosophila haemocyte-specific protein, hemolectin, similar to human von Willebrand factor.

PubMed Central

Goto, A; Kumagai, T; Kumagai, C; Hirose, J; Narita, H; Mori, H; Kadowaki, T; Beck, K; Kitagawa, Y

2001-01-01

We identified a novel Drosophila protein of approximately 400 kDa, hemolectin (d-Hml), secreted from haemocyte-derived Kc167 cells. Its 11.7 kbp cDNA contains an open reading frame of 3843 amino acid residues, with conserved domains in von Willebrand factor (VWF), coagulation factor V/VIII and complement factors. The d-hml gene is located on the third chromosome (position 70C1-5) and consists of 26 exons. The major part of d-Hml consists of well-known motifs with the organization: CP1-EG1-CP2-EG2-CP3-VD1-VD2-VD'-VD3-VC1-VD"-VD"'-FC1-FC2-VC2-LA1-VD4-VD5-VC3-VB1-VB2-VC4-VC5-CK1 (CP, complement-control protein domain; EG, epidermal-growth-factor-like domain; VB, VC, VD, VWF type B-, C- and D-like domains; VD', VD", VD"', truncated C-terminal VDs; FC, coagulation factor V/VIII type C domain; LA, low-density-lipoprotein-receptor class A domain; CK, cysteine knot domain). The organization of VD1-VD2-VD'-VD3, essential for VWF to be processed by furin, to bind to coagulation factor VIII and to form interchain disulphide linkages, is conserved. The 400 kDa form of d-Hml was sensitive to acidic cleavage near the boundary between VD2 and VD', where the cleavage site of pro-VWF is located. Agarose-gel electrophoresis of metabolically radiolabelled d-Hml suggested that it is secreted from Kc167 cells mainly as dimers. Resembling VWF, 7.9% (305 residues) of cysteine residues on the d-Hml sequence had well-conserved positions in each motif. Coinciding with the development of phagocytic haemocytes, d-hml transcript was detected in late embryos and larvae. Its low-level expression in adult flies was induced by injury at any position on the body. PMID:11563973

Genome-wide analyses of HTLV-1aD strains from Cape Verde, Africa.

PubMed

Zanella, Louise; Pina-Araujo I, Isabel de; Morgado, Mariza G; Vicente, Ana Carolina

2016-09-01

We characterised and reported the first full-length genomes of Human T-cell Lymphotropic Virus Type 1 subgroup HTLV-1aD (CV21 and CV79). This subgroup is one of the major determinants of HTLV-1 infections in North and West Africa, and recombinant strains involving this subgroup have been recently demonstrated. The CV21 and CV79 strains from Cape Verde/Africa were characterised as pure HTLV-1aD genomes, comparative analyses including HTLV-1 subtypes and subgroups revealed HTLV-1aD signatures in the envelope, pol, and pX regions. These genomes provide original information that will contribute to further studies on HTLV-1a epidemiology and evolution.

Identification, Characterization and Rescue of a Novel Vasopressin-2 Receptor Mutation Causing Nephrogenic Diabetes Insipidus

PubMed Central

Ranadive, Sayali A.; Ersoy, Baran; Favre, Helene; Cheung, Clement C.; Rosenthal, Stephen M.; Miller, Walter L.; Vaisse, Christian

2018-01-01

SUMMARY Objective X-linked nephrogenic diabetes insipidus (XNDI), caused by mutations in the V2 vasopressin receptor (V2R), is clinically distinguished from central diabetes insipidus (CDI) by elevated serum vasopressin (AVP) levels and unresponsiveness to 1-desamino-8-D-arginine vasopressin (DDAVP). We report two infants with XNDI, and present the characterization and functional rescue of a novel V2R mutation. Patients Two male infants presented with poor growth and hypernatremia. Both patients had measurable pre-treatment serum AVP and polyuria that did not respond to DDAVP, suggesting NDI. However, both also had absent posterior pituitary bright spot on MRI, which is a finding more typical of CDI. Methods The AVPR2 gene encoding V2R was sequenced. The identified novel missense mutation was re-created by site-directed mutagenesis and expressed in HEK293 cells. V2R activity was assessed by the ability of transfected cells to produce cAMP in response to stimulation with DDAVP. Membrane localization of V2R was assessed by fluorescence microscopy. Results Patient 1 had a deletion of AVPR2; patient 2 had the novel mutation L57R. In transiently transfected HEK293 cells, DDAVP induced detectable but severely impaired L57R V2R activity compared to cells expressing wild-type V2R. Fluorescence microscopy showed that myc-tagged wild-type V2R localized to the cell membrane while L57R V2R remained intracellular. A non-peptide V2R chaperone, SR121463, partially rescued L57R V2R function by allowing it to reach the cell membrane. Conclusions L57R V2R has impaired in vitro activity that can be partially improved by treatment with a V2R chaperone. The posterior pituitary hyperintensity may be absent in infants with XNDI. PMID:19170711

Suppression of bacterial cell-cell signalling, biofilm formation and type III secretion system by citrus flavonoids.

PubMed

Vikram, A; Jayaprakasha, G K; Jesudhasan, P R; Pillai, S D; Patil, B S

2010-08-01

This study investigated the quorum sensing, biofilm and type three secretion system (TTSS) inhibitory properties of citrus flavonoids. Flavonoids were tested for their ability to inhibit quorum sensing using Vibrio harveyi reporter assay. Biofilm assays were carried out in 96-well plates. Inhibition of biofilm formation in Escherichia coli O157:H7 and V. harveyi by citrus flavonoids was measured. Furthermore, effect of naringenin on expression of V. harveyi TTSS was investigated by semi-quantitative PCR. Differential responses for different flavonoids were observed for different cell-cell signalling systems. Among the tested flavonoids, naringenin, kaempferol, quercetin and apigenin were effective antagonists of cell-cell signalling. Furthermore, these flavonoids suppressed the biofilm formation in V. harveyi and E. coli O157:H7. In addition, naringenin altered the expression of genes encoding TTSS in V. harveyi. The results of the study indicate a potential modulation of bacterial cell-cell communication, E. coli O157:H7 biofilm and V. harveyi virulence, by flavonoids especially naringenin, quercetin, sinensetin and apigenin. Among the tested flavonoids, naringenin emerged as potent and possibly a nonspecific inhibitor of autoinducer-mediated cell-cell signalling. Naringenin and other flavonoids are prominent secondary metabolites present in citrus species. Therefore, citrus, being a major source of some of these flavonoids and by virtue of widely consumed fruit, may modulate the intestinal microflora. Currently, a limited number of naturally occurring compounds have demonstrated their potential in inhibition of cell-cell communications; therefore, citrus flavonoids may be useful as lead compounds for the development of antipathogenic agents.

Probing inhibitory effects of nanocrystalline cellulose: inhibition versus surface charge

NASA Astrophysics Data System (ADS)

Male, Keith B.; Leung, Alfred C. W.; Montes, Johnny; Kamen, Amine; Luong, John H. T.

2012-02-01

NCC derived from different biomass sources was probed for its plausible cytotoxicity by electric cell-substrate impedance sensing (ECIS). Two different cell lines, Spodoptera frugiperda Sf9 insect cells and Chinese hamster lung fibroblast V79, were exposed to NCC and their spreading and viability were monitored and quantified by ECIS. Based on the 50%-inhibition concentration (ECIS50), none of the NCC produced was judged to have any significant cytotoxicity on these two cell lines. However, NCC derived from flax exhibited the most pronounced inhibition on Sf9 compared to hemp and cellulose powder. NCCs from flax and hemp pre-treated with pectate lyase were also less inhibitory than NCCs prepared from untreated flax and hemp. Results also suggested a correlation between the inhibitory effect and the carboxylic acid contents on the NCC.

Glycolytic control of vacuolar-type ATPase activity: A mechanism to regulate influenza viral infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohio, Hinissan P.; Adamson, Amy L., E-mail: aladamso@uncg.edu

As new influenza virus strains emerge, finding new mechanisms to control infection is imperative. In this study, we found that we could control influenza infection of mammalian cells by altering the level of glucose given to cells. Higher glucose concentrations induced a dose-specific increase in influenza infection. Linking influenza virus infection with glycolysis, we found that viral replication was significantly reduced after cells were treated with glycolytic inhibitors. Addition of extracellular ATP after glycolytic inhibition restored influenza infection. We also determined that higher levels of glucose promoted the assembly of the vacuolar-type ATPase within cells, and increased vacuolar-type ATPase proton-transportmore » activity. The increase of viral infection via high glucose levels could be reversed by inhibition of the proton pump, linking glucose metabolism, vacuolar-type ATPase activity, and influenza viral infection. Taken together, we propose that altering glucose metabolism may be a potential new approach to inhibit influenza viral infection. - Highlights: • Increased glucose levels increase Influenza A viral infection of MDCK cells. • Inhibition of the glycolytic enzyme hexokinase inhibited Influenza A viral infection. • Inhibition of hexokinase induced disassembly the V-ATPase. • Disassembly of the V-ATPase and Influenza A infection was bypassed with ATP. • The state of V-ATPase assembly correlated with Influenza A infection of cells.« less

Prevention of Ca(2+)-mediated action potentials in GABAergic local circuit neurones of rat thalamus by a transient K+ current.

PubMed Central

Pape, H C; Budde, T; Mager, R; Kisvárday, Z F

1994-01-01

1. Neurones enzymatically dissociated from the rat dorsal lateral geniculate nucleus (LGN) were identified as GABAergic local circuit interneurones and geniculocortical relay cells, based upon quantitative analysis of soma profiles, immunohistochemical detection of GABA or glutamic acid decarboxylase, and basic electrogenic behaviour. 2. During whole-cell current-clamp recording, isolated LGN neurones generated firing patterns resembling those in intact tissue, with the most striking difference relating to the presence in relay cells of a Ca2+ action potential with a low threshold of activation, capable of triggering fast spikes, and the absence of a regenerative Ca2+ response with a low threshold of activation in local circuit cells. 3. Whole-cell voltage-clamp experiments demonstrated that both classes of LGN neurones possess at least two voltage-dependent membrane currents which operate in a range of membrane potentials negative to the threshold for generation of Na(+)-K(+)-mediated spikes: the T-type Ca2+ current (IT) and an A-type K+ current (IA). Taking into account the differences in membrane surface area, the average size of IT was similar in the two types of neurones, and interneurones possessed a slightly larger A-conductance. 4. In local circuit neurones, the ranges of steady-state inactivation and activation of IT and IA were largely overlapping (VH = 81.1 vs. -82.8 mV), both currents activated at around -70 mV, and they rapidly increased in amplitude with further depolarization. In relay cells, the inactivation curve of IT was negatively shifted along the voltage axis by about 20 mV compared with that of IA (Vh = -86.1 vs. -69.2 mV), and the activation threshold for IT (at -80 mV) was 20 mV more negative than that for IA. In interneurones, the activation range of IT was shifted to values more positive than that in relay cells (Vh = -54.9 vs. -64.5 mV), whereas the activation range of IA was more negative (Vh = -25.2 vs. -14.5 mV). 5. Under whole-cell voltage-clamp conditions that allowed the combined activation of Ca2+ and K+ currents, depolarizing voltage steps from -110 mV evoked inward currents resembling IT in relay cells and small outward currents indicative of IA in local circuit neurones. After blockade of IA with 4-aminopyridine (4-AP), the same pulse protocol produced IT in both types of neurones. Under current clamp, 4-AP unmasked a regenerative membrane depolarization with a low threshold of activation capable of triggering fast spikes in local circuit neurones.(ABSTRACT TRUNCATED AT 400 WORDS) Images Figure 1 PMID:7965855

Regulation of branchial V-H(+)-ATPase, Na(+)/K(+)-ATPase and NHE2 in response to acid and base infusions in the Pacific spiny dogfish (Squalus acanthias).

PubMed

Tresguerres, Martin; Katoh, Fumi; Fenton, Heather; Jasinska, Edyta; Goss, Greg G

2005-01-01

To study the mechanisms of branchial acid-base regulation, Pacific spiny dogfish were infused intravenously for 24 h with either HCl (495+/- 79 micromol kg(-1) h(-1)) or NaHCO(3) (981+/-235 micromol kg(-1) h(-1)). Infusion of HCl produced a transient reduction in blood pH. Despite continued infusion of acid, pH returned to normal by 12 h. Infusion of NaHCO(3) resulted in a new steady-state acid-base status at approximately 0.3 pH units higher than the controls. Immunostained serial sections of gill revealed the presence of separate vacuolar proton ATPase (V-H(+)-ATPase)-rich or sodium-potassium ATPase (Na(+)/K(+)-ATPase)-rich cells in all fish examined. A minority of the cells also labeled positive for both transporters. Gill cell membranes prepared from NaHCO(3)-infused fish showed significant increases in both V-H(+)-ATPase abundance (300+/-81%) and activity. In addition, we found that V-H(+)-ATPase subcellular localization was mainly cytoplasmic in control and HCl-infused fish, while NaHCO(3)-infused fish demonstrated a distinctly basolateral staining pattern. Western analysis in gill membranes from HCl-infused fish also revealed increased abundance of Na(+)/H(+) exchanger 2 (213+/-5%) and Na(+)/K(+)-ATPase (315+/-88%) compared to the control.

SARS coronavirus papain-like protease up-regulates the collagen expression through non-Samd TGF-β1 signaling.

PubMed

Wang, Ching-Ying; Lu, Chien-Yi; Li, Shih-Wen; Lai, Chien-Chen; Hua, Chun-Hung; Huang, Su-Hua; Lin, Ying-Ju; Hour, Mann-Jen; Lin, Cheng-Wen

2017-05-02

SARS coronavirus (CoV) papain-like protease (PLpro) reportedly induced the production of TGF-β1 through p38 MAPK/STAT3-meidated Egr-1-dependent activation (Sci. Rep. 6, 25754). This study investigated the correlation of PLpro-induced TGF-β1 with the expression of Type I collagen in human lung epithelial cells and mouse pulmonary tissues. Specific inhibitors for TGF-βRI, p38 MAPK, MEK, and STAT3 proved that SARS-CoV PLpro induced TGF-β1-dependent up-regulation of Type I collagen in vitro and in vivo. Subcellular localization analysis of SMAD3 and SMAD7 indicated that non-SMAD pathways in TGF-β1 signaling involved in the production of Type I collagen in transfected cells with pSARS-PLpro. Comprehensive analysis of ubiquitin-conjugated proteins using immunoprecipitation and nanoLC-MS/MS indicated that SARS-CoV PLpro caused the change in the ubiquitination profile of Rho GTPase family proteins, in which linked with the increase of Rho-like GTPase family proteins. Moreover, selective inhibitors TGF-βRI and STAT6 (AS1517499) ascertained that STAT6 activation was required for PLpro-induced TGF-β1-dependent up-regulation of Type I collagen in human lung epithelial cells. The results showed that SARS-CoV PLpro stimulated TGF-β1-dependent expression of Type I collagen via activating STAT6 pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

A screen-printed circular-type paper-based glucose/O2 biofuel cell

NASA Astrophysics Data System (ADS)

Shitanda, Isao; Nohara, Saki; Hoshi, Yoshinao; Itagaki, Masayuki; Tsujimura, Seiya

2017-08-01

The printable paper-based enzymatic biofuel cell (PBFC) to directly power small devices is an important objective for realizing cost-effective and disposable energy harvesting devices. In the present study, a screen-printed circular-type PBFC, composed of a series of 5 individual cells, was constructed. The PBFC exhibited the open circuit potential of 2.65 V and maximum power of 350 μW at 1.55 V, which were sufficient to illuminate an LED without requiring a booster circuit. The output voltage of this PBFC can also be easily adjusted as required.

Molecular cloning and characterization of V2-type receptor in two ray-finned fish, gray bichir, Polypterus senegalus and medaka, Oryzias latipes.

PubMed

Konno, Norifumi; Kurosawa, Mayumi; Kaiya, Hiroyuki; Miyazato, Mikiya; Matsuda, Kouhei; Uchiyama, Minoru

2010-07-01

In tetrapods, vasopressin (VP) and vasotocin (VT) are involved in various aspects of physiology and behavior including osmoregulation, cardiovascular function, reproduction, stress response and social behavior. Pharmacological and molecular studies have identified three types of VP/VT receptors, V1a-type (V1aR), V1b-type (V1bR) and V2-type (V2R). On the other hand, only V1aR has so far been identified in teleosts. In the present study, we successfully cloned V2Rs from two ray-finned fish, gray bichir and medaka. Phylogenetic analysis showed that the cloned receptors belong to the V2R group of lobe-finned fish and tetrapods. The amino acid sequences of bichir V2R and medaka V2R were high identity (60-65.5% and 53.2-80.9%, respectively) with other known V2R members, respectively. Reverse transcriptase PCR revealed that ray-finned fish V2R transcripts have been detected in various tissues including brain, gill, heart, liver, kidney and reproductive organs, suggesting that ray-finned fish V2R might mediate multiple functions of VT. In functional analysis, the cells transfected with the cloned receptors responded with the accumulation of intracellular cAMP in a concentration-dependent manner following VT stimulation, but not respond with [Ca(2+)]i. Furthermore, pretreatment with mammalian V2R antagonist (OPC-31260) to the cells transfected with medaka V2R significantly inhibited an increase of the VT-induced intracellular cAMP. These results suggest that ray-finned fish possess a functional V2R linked to adenylate cyclase and the cAMP signaling pathway as well as V2Rs of lobe-finned fish and tetrapods. Thus, the present study suggests that functional V2R evolved prior to the divergence of the ray- and lobe-finned fish lineages. Copyright 2010 Elsevier Inc. All rights reserved.

Cell-to-Cell Contact and Nectin-4 Govern Spread of Measles Virus from Primary Human Myeloid Cells to Primary Human Airway Epithelial Cells.

PubMed

Singh, Brajesh K; Li, Ni; Mark, Anna C; Mateo, Mathieu; Cattaneo, Roberto; Sinn, Patrick L

2016-08-01

Measles is a highly contagious, acute viral illness. Immune cells within the airways are likely first targets of infection, and these cells traffic measles virus (MeV) to lymph nodes for amplification and subsequent systemic dissemination. Infected immune cells are thought to return MeV to the airways; however, the mechanisms responsible for virus transfer to pulmonary epithelial cells are poorly understood. To investigate this process, we collected blood from human donors and generated primary myeloid cells, specifically, monocyte-derived macrophages (MDMs) and dendritic cells (DCs). MDMs and DCs were infected with MeV and then applied to primary cultures of well-differentiated airway epithelial cells from human donors (HAE). Consistent with previous results obtained with free virus, infected MDMs or DCs were incapable of transferring MeV to HAE when applied to the apical surface. Likewise, infected MDMs or DCs applied to the basolateral surface of HAE grown on small-pore (0.4-μm) support membranes did not transfer virus. In contrast, infected MDMs and DCs applied to the basolateral surface of HAE grown on large-pore (3.0-μm) membranes successfully transferred MeV. Confocal microscopy demonstrated that MDMs and DCs are capable of penetrating large-pore membranes but not small-pore membranes. Further, by using a nectin-4 blocking antibody or recombinant MeV unable to enter cells through nectin-4, we demonstrated formally that transfer from immune cells to HAE occurs in a nectin-4-dependent manner. Thus, both infected MDMs and DCs rely on cell-to-cell contacts and nectin-4 to efficiently deliver MeV to the basolateral surface of HAE. Measles virus spreads rapidly and efficiently in human airway epithelial cells. This rapid spread is based on cell-to-cell contact rather than on particle release and reentry. Here we posit that MeV transfer from infected immune cells to epithelial cells also occurs by cell-to-cell contact rather than through cell-free particles. In addition, we sought to determine which immune cells transfer MeV infectivity to the human airway epithelium. Our studies are based on two types of human primary cells: (i) myeloid cells generated from donated blood and (ii) well-differentiated airway epithelial cells derived from donor lungs. We show that different types of myeloid cells, i.e., monocyte-derived macrophages and dendritic cells, transfer infection to airway epithelial cells. Furthermore, cell-to-cell contact is an important component of successful MeV transfer. Our studies elucidate a mechanism by which the most contagious human respiratory virus is delivered to the airway epithelium. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

CD79B limits response of diffuse large B cell lymphoma to ibrutinib.

PubMed

Kim, Joo Hyun; Kim, Won Seog; Ryu, Kyungju; Kim, Seok Jin; Park, Chaehwa

2016-01-01

Blockage of B cell receptor signaling with ibrutinib presents a promising clinical approach for treatment of B-cell malignancies. However, many patients show primary resistance to the drug or develop secondary resistance. In the current study, cDNA microarray and Western blot analyses revealed CD79B upregulation in the activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL) that display differential resistance to ibrutinib. CD79B overexpression was sufficient to induce resistance to ibrutinib and enhanced AKT and MAPK activation, indicative of an alternative mechanism underlying resistance. Conversely, depletion of CD79B sensitized primary refractory cells to ibrutinib and led to reduced phosphorylation of AKT or MAPK. Combination of the AKT inhibitor or the MAPK inhibitor with ibrutinib resulted in circumvention of both primary and acquired resistance in ABC-DLBCL. Our data collectively indicate that CD79B overexpression leading to activation of AKT/MAPK is a potential mechanism underlying primary ibrutinib resistance in ABC-DLBCL, and support its utility as an effective biomarker to predict therapeutic response to ibrutinib.

T cell-independent and T cell-dependent immunoglobulin G responses to polyomavirus infection are impaired in complement receptor 2-deficient mice.

PubMed

Szomolanyi-Tsuda, Eva; Seedhom, Mina O; Carroll, Michael C; Garcea, Robert L

2006-08-15

Polyomavirus (PyV) infection induces protective T cell-independent (TI) IgM and IgG antibody responses in T cell-deficient mice, but these responses are not generated by immunization with viral proteins or virus like particles. We hypothesized that innate signals contribute to the generation of isotype-switched antiviral antibody responses. We studied the role of complement receptor (CR2) engagement in TI and T cell-dependent (TD) antibody responses to PyV using CR2-deficient mice. Antiviral IgG responses were reduced by 80-40% in CR2-/- mice compared to wild type. Adoptive transfer experiments demonstrated the need for CR2 not only in TD, but also in TI IgG responses to PyV. Transfer of CR2-/- B lymphocytes to SCID mice resulted in TI antiviral IgG responses that corresponded to 10% of that seen in wild-type B cell-reconstituted mice. Thus, our studies revealed a profound dependence of TI and TD antiviral antibody responses on CR2-mediated signals in PyV-infected mice, where the viral antigen is abundant and persistent.

Persistence of the Z =28 Shell Gap Around 78Ni: First Spectroscopy of 79Cu

NASA Astrophysics Data System (ADS)

Olivier, L.; Franchoo, S.; Niikura, M.; Vajta, Z.; Sohler, D.; Doornenbal, P.; Obertelli, A.; Tsunoda, Y.; Otsuka, T.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Gillibert, A.; Isobe, T.; Lapoux, V.; Matsushita, M.; Momiyama, S.; Motobayashi, T.; Otsu, H.; Péron, C.; Peyaud, A.; Pollacco, E. C.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Sasano, M.; Shiga, Y.; Takeuchi, S.; Taniuchi, R.; Uesaka, T.; Wang, H.; Yoneda, K.; Browne, F.; Chung, L. X.; Dombradi, Z.; Flavigny, F.; Giacoppo, F.; Gottardo, A.; Hadyńska-Klek, K.; Korkulu, Z.; Koyama, S.; Kubota, Y.; Lee, J.; Lettmann, M.; Louchart, C.; Lozeva, R.; Matsui, K.; Miyazaki, T.; Nishimura, S.; Ogata, K.; Ota, S.; Patel, Z.; Sahin, E.; Shand, C.; Söderström, P.-A.; Stefan, I.; Steppenbeck, D.; Sumikama, T.; Suzuki, D.; Werner, V.; Wu, J.; Xu, Z.

2017-11-01

In-beam γ -ray spectroscopy of 79Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a 80Zn beam at 270 MeV /nucleon . The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z =28 gap at N =50 remains large. The results show that the 79Cu nucleus can be described in terms of a valence proton outside a 78Ni core, implying the magic character of the latter.

Forward-biased current annealing of radiation degraded indium phosphide and gallium arsenide solar cells

NASA Technical Reports Server (NTRS)

Michael, Sherif; Cypranowski, Corinne; Anspaugh, Bruce

1990-01-01

The preliminary results of a novel approach to low-temperature annealing of previously irradiated indium phosphide and gallium arsenide solar cells are reported. The technique is based on forward-biased current annealing. The two types of III-V solar cells were irradiated with 1-MeV electrons to a fluence level of (1-10) x 10 to the 14th electrons/sq cm. Several annealing attempts were made, varying all conditions. Optimum annealing was achieved when cells were injected with minority currents at a constant 90 C. The current density for each type of cell was also determined. Significant recovery of degraded parameters was achieved in both cases. However, the InP cell recovery notably exceeded the recovery in GaAs cells. The recovery is thought to be caused by current-stimulated reordering of the radiator-induced displacement damage. Both types of cell were then subjected to several cycles of irradiation and annealing. The results were also very promising. The significant recovery of degraded cell parameters at low temperature might play a major role in considerably extending the end of life of future spacecraft.

Mimicry of erythropoietin and interleukin-6 signalling by an antibody/cytokine receptor chimera in murine myeloid 32D cells.

PubMed

Kawahara, Masahiro; Ueda, Hiroshi; Tsumoto, Kouhei; Kumagai, Izumi; Nagamune, Teruyuki

2007-04-01

We have previously designed antibody-cytokine receptor chimeras that could respond to a cognate antigen. While these chimeric receptors were functional, it has not been investigated exactly how they mimic signal transduction through corresponding wild-type receptors. In this study, we compared the growth properties and the phosphorylation status of intracellular signal transducers between the erythropoietin receptor (EpoR)- or gp130-based chimeric receptors and wild-type EpoR or EpoR-gp130 chimera, respectively. Expression plasmids, encoding V(H) or V(L) region of anti-hen egg lysozyme (HEL) antibody HyHEL-10 tethered to a pair of extracellular D2 domain of EpoR and transmembrane/cytoplasmic domains of either EpoR or gp130, were constructed, and pairs of chimeric receptor combinations (V(H)-EpoR and V(L)-EpoR, V(H)-gp130 and V(L)-gp130, V(H)-EpoR and V(L)-gp130, V(H)-gp130 and V(L)-EpoR) were expressed in an IL-3-dependent myeloid cell line, 32D. Growth assay revealed that the transfectants all grew in a HEL-dependent manner. As for phosphorylation of Stat3, Stat5, ERK and Akt, the chimeric receptors showed similar activation pattern of signalling molecules with wild-type receptors, although the chimeric receptors showed ligand-independency and a little lower maximal phosphorylation than the corresponding wild-type receptors. The results demonstrate that antibody-receptor chimeras could substantially mimic wild-type receptors.

Bacterial contamination of boar semen affects the litter size.

PubMed

Maroto Martín, Luis O; Muñoz, Eduardo Cruz; De Cupere, Françoise; Van Driessche, Edilbert; Echemendia-Blanco, Dannele; Rodríguez, José M Machado; Beeckmans, Sonia

2010-07-01

One hundred and fifteen semen samples were collected from 115 different boars from two farms in Cuba. The boars belonged to five different breeds. Evaluation of the semen sample characteristics (volume, pH, colour, smell, motility of sperm cells) revealed that they meet international standards. The samples were also tested for the presence of agglutinated sperm cells and for bacterial contamination. Seventy five percent of the ejaculates were contaminated with at least one type of bacteria and E. coli was by far the major contaminant, being present in 79% of the contaminated semen samples (n=68). Other contaminating bacteria belonged to the genera Proteus (n=31), Serratia (n=31), Enterobacter (n=24), Klebsiella (n=12), Staphylococcus (n=10), Streptococcus (n=8) and Pseudomonas (n=7). Only in one sample anaerobic bacteria were detected. Pearson's analysis of the data revealed that there is a positive correlation between the presence of E. coli and sperm agglutination, and a negative correlation between sperm agglutination and litter size. One-way ANOVA and post hoc Tukey analysis of 378 litters showed that the litter size is significantly reduced when semen is used that is contaminated with spermagglutinating E. coli above a threshold value of 3.5x10(3)CFU/ml. Copyright 2010 Elsevier B.V. All rights reserved.

Genotoxicity of carbon nanofibers: Are they potentially more or less dangerous than carbon nanotubes or asbestos?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kisin, E.R.; Murray, A.R.; Sargent, L.

The production of carbon nanofibers and nanotubes (CNF/CNT) and their composite products is increasing globally. CNF are generating great interest in industrial sectors such as energy production and electronics, where alternative materials may have limited performance or are produced at a much higher cost. However, despite the increasing industrial use of carbon nanofibers, information on their potential adverse health effects is limited. In the current study, we examine the cytotoxic and genotoxic potential of carbon-based nanofibers (Pyrograf (registered) -III) and compare this material with the effects of asbestos fibers (crocidolite) or single-walled carbon nanotubes (SWCNT). The genotoxic effects in themore » lung fibroblast (V79) cell line were examined using two complementary assays: the comet assay and micronucleus (MN) test. In addition, we utilized fluorescence in situ hybridization to detect the chromatin pan-centromeric signals within the MN indicating their origin by aneugenic (chromosomal malsegregation) or clastogenic (chromosome breakage) mechanisms. Cytotoxicity tests revealed a concentration- and time-dependent loss of V79 cell viability after exposure to all tested materials in the following sequence: asbestos > CNF > SWCNT. Additionally, cellular uptake and generation of oxygen radicals was seen in the murine RAW264.7 macrophages following exposure to CNF or asbestos but not after administration of SWCNT. DNA damage and MN induction were found after exposure to all tested materials with the strongest effect seen for CNF. Finally, we demonstrated that CNF induced predominately centromere-positive MN in primary human small airway epithelial cells (SAEC) indicating aneugenic events. Further investigations are warranted to elucidate the possible mechanisms involved in CNF-induced genotoxicity.« less

Structural Aspects of Antioxidant and Genotoxic Activities of Two Flavonoids Obtained from Ethanolic Extract of Combretum leprosum

PubMed Central

Viau, Cassiana Macagnan; Moura, Dinara Jaqueline; Pflüger, Pricila; Facundo, Valdir Alves

2016-01-01

Combretum leprosum Mart., a member of the Combretaceae family, is a traditionally used Brazilian medicinal plant, although no evidence in the literature substantiates its antioxidant action and the safety of its use. We evaluated the antioxidant properties of the ethanolic extract (EE) from flowers of C. leprosum and its isolated products 5,3′-dihydroxy-3,7,4′-trimethoxyflavone (FCL2) and 5,3′,4′-trihydroxy-3,7-dimethoxyflavone (FCL5) in Saccharomyces cerevisiae strains proficient and deficient in antioxidant defenses. Their mutagenic activity was also assayed in S. cerevisiae, whereas cytotoxic and genotoxic properties were evaluated by MTT and Comet Assays, respectively, in V79 cells. We show that the EE, FCL2, and FCL5 have a significant protective effect against H2O2. FCL2 showed a better antioxidant action, which can be related to the activation of the 3′-OH in the presence of a methoxyl group at 4′ position in the B-ring of the molecule, while flavonoids did not induce mutagenesis in yeast, and the EE was mutagenic at high concentrations. The toxicity of these compounds in V79 cells increases from FCL2 = FCL5 < EE; although not cytotoxic, FCL5 induced an increase in DNA damage. The antioxidant effect, along with the lower toxicity and the absence of genotoxicity, suggests that FCL2 could be suitable for pharmacological use. PMID:27478483

Reduction of low potential electron acceptors requires the CbcL inner membrane cytochrome of Geobacter sulfurreducens.

PubMed

Zacharoff, Lori; Chan, Chi Ho; Bond, Daniel R

2016-02-01

The respiration of metals by the bacterium Geobacter sulfurreducens requires electrons generated by metabolism to pass from the interior of the cell to electron acceptors beyond the cell membranes. The G. sulfurreducens inner membrane multiheme c-type cytochrome ImcH is required for respiration to extracellular electron acceptors with redox potentials greater than -0.1 V vs. SHE, but ImcH is not essential for electron transfer to lower potential acceptors. In contrast, deletion of cbcL, encoding an inner membrane protein consisting of b-type and multiheme c-type cytochrome domains, severely affected reduction of low potential electron acceptors such as Fe(III)-oxides and electrodes poised at -0.1 V vs. SHE. Catalytic cyclic voltammetry of a ΔcbcL strain growing on poised electrodes revealed a 50 mV positive shift in driving force required for electron transfer out of the cell. In non-catalytic conditions, low-potential peaks present in wild type biofilms were absent in ∆cbcL mutants. Expression of cbcL in trans increased growth at low redox potential and restored features to cyclic voltammetry. This evidence supports a model where CbcL is a component of a second electron transfer pathway out of the G. sulfurreducens inner membrane that dominates when redox potential is at or below -0.1 V vs. SHE. Copyright © 2015. Published by Elsevier B.V.

Magnetron sputtering fabrication and photoelectric properties of WSe2 film solar cell device

NASA Astrophysics Data System (ADS)

Mao, Xu; Zou, Jianpeng; Li, Hongchao; Song, Zhengqi; He, Siru

2018-06-01

Tungsten diselenide (WSe2) films with different growing orientations exhibit diverse photoelectric properties. The WSe2 film with C-axis⊥substrate texture has been prepared and applied to thin-film solar cells. W nanofilms with a thickness of 270 nm were deposited onto the Mo bottom electrode and then heat-treated in selenium vapor to synthesize WSe2 films with a thickness of 1 μm. ZnO films were deposited onto WSe2 films to form a P-N junction and ITO films were deposited subsequently as the conductive layer. X-ray diffractometry, scanning electron microscopy and UV-vis-NIR spectro-analysis instrument were employed to analyze the phase composition, optical absorptivity and micromorphology of WSe2 films and the WSe2 solar cell device. WSe2 films exhibit excellent photoelectric performance with an optical absorption coefficient greater than 105 cm-1 across the visible spectrum. The calculated direct and indirect band gap of the WSe2 films is 1.48 eV and 1.25 eV, respectively. With the application of standard glass/Mo/WSe2/ZnO/ITO/Ag device structure, the open-circuit voltage of the battery device is 82 mV. The short-circuit current density is 2.98 mA/cm2 and the filling factor is 0.32. The photoelectric conversion efficiency of the WSe2 film solar cell device is 0.79%.

Selective Effects of Training Against Weight and Inertia on Muscle Mechanical Properties.

PubMed

Djuric, Sasa; Cuk, Ivan; Sreckovic, Sreten; Mirkov, Dragan; Nedeljkovic, Aleksandar; Jaric, Slobodan

2016-10-01

To explore the effects of training against mechanically different types of loads on muscle force (F), velocity (V), and power (P) outputs. Subjects practiced maximum bench throws over 8 wk against a bar predominantly loaded by approximately constant external force (weight), weight plates (weight plus inertia), or weight plates whose weight was compensated by a constant external force pulling upward (inertia). Instead of a typically applied single trial performed against a selected load, the pretest and posttest consisted of the same task performed against 8 different loads ranging from 30% to 79% of the subject's maximum strength applied by adding weight plates to the bar. That provided a range of F and V data for subsequent modeling by linear F-V regression revealing the maximum F (F-intercept), V (V-intercept), and P (P = FV/4). Although all 3 training conditions resulted in increased P, the inertia type of the training load could be somewhat more effective than weight. An even more important finding was that the P increase could be almost exclusively based on a gain in F, V, or both when weight, inertia, or weight-plus-inertia training load were applied, respectively. The inertia training load is more effective than weight in increasing P and weight and inertia may be applied for selective gains in F and V, respectively, whereas the linear F-V model obtained from loaded trials could be used for discerning among muscle F, V, and P.

Investigation of reliability attributes and accelerated stress factors of terrestrial solar cells. First annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prince, J.L.; Lathrop, J.W.

1979-05-01

The results of accelerated stress testing of four different types of silicon terrestrial solar cells are discussed. The accelerated stress tests used included bias-temperature tests, bias-temperature-humidity tests, thermal cycle and thermal shock tests, and power cycle tests. Characterization of the cells was performed before stress testing and at periodic down-times, using electrical measurement, visual inspection, and metal adherence pull tests. Electrical parameters measured included short-circuit current, I/sub sc/, open circuit voltage, V/sub oc/, and output power, voltage, and current at the maximum power point, P/sub m/, V/sub m/, and I/sub m/ respectively. Incorporated in the report are the distributions ofmore » the prestress electrical data for all cell types. Data was also obtained on cell series and shunt resistance. Significant differences in the response to the various stress tests was observed between cell types. On the basis of the experience gained in this research work, a suggested Reliability Qualification Test Schedule was developed.« less

The Distributions of Voltage-Gated K+ current Subtypes in Different Cell Sizes from Adult Mouse Dorsal Root Ganglia.

PubMed

Sheng, Anqi; Hong, Jiangru; Zhang, Lulu; Zhang, Yan; Zhang, Guangqin

2018-03-29

Voltage-gated K + (K V ) currents play a crucial role in regulating pain by controlling neuronal excitability, and are divided into transient A-type currents (I A ) and delayed rectifier currents (I K ). The dorsal root ganglion (DRG) neurons are heterogeneous and the subtypes of K V currents display different levels in distinct cell sizes. To observe correlations of the subtypes of K V currents with DRG cell sizes, K V currents were recorded by whole-cell patch clamp in freshly isolated mouse DRG neurons. Results showed that I A occupied a high proportion in K V currents in medium- and large-diameter DRG neurons, whereas I K possessed a larger proportion of K V currents in small-diameter DRG neurons. A lower correlation was found between the proportion of I A or I K in K V currents and cell sizes. These data suggest that I A channels are mainly expressed in medium and large cells and I K channels are predominantly expressed in small cells.

Study of superhydrophobic electrosprayed catalyst layers using a localized reference electrode technique

NASA Astrophysics Data System (ADS)

Chaparro, A. M.; Ferreira-Aparicio, P.; Folgado, M. A.; Brightman, E.; Hinds, G.

2016-09-01

The performance of electrosprayed cathode catalyst layers in a polymer electrolyte membrane fuel cell (PEMFC) is studied using a localized reference electrode technique. Single cells with an electrosprayed cathode catalyst layer show an increase of >20% in maximum power density under standard testing conditions, compared with identical cells assembled with a conventional, state-of-the-art, gas diffusion cathode. When operated at high current density (1.2 A cm-2) the electrosprayed catalyst layers show more homogeneous distribution of the localized cathode potential, with a standard deviation from inlet to outlet of <50 mV, compared with 79 mV for the conventional gas diffusion cathode. Higher performance and homogeneity of cell response is attributed to the superhydrophobic nature of the macroporous electrosprayed catalyst layer structure, which enhances the rate of expulsion of liquid water from the cathode. On the other hand, at low current densities (<0.5 A cm-2), the electrosprayed layers exhibit more heterogeneous distribution of cathode potential than the conventional cathodes; this behavior is attributed to less favorable kinetics for oxygen reduction in very hydrophobic catalyst layers. The optimum performance may be obtained with electrosprayed catalyst layers employing a high Pt/C catalyst ratio.

Dedicated high dose rate 192Ir brachytherapy radiation fields for in vitro cell exposures at variable source-target cell distances: killing of mammalian cells depends on temporal dose rate fluctuation

NASA Astrophysics Data System (ADS)

Veigel, Cornelia; Hartmann, Günther H.; Fritz, Peter; Debus, Jürgen; Weber, Klaus-Josef

2017-02-01

Afterloading brachytherapy is conducted by the stepwise movement of a radioactive source through surgically implanted applicator tubes where at predefined dwell positions calculated dwell times optimize spatial dose delivery with respect to a planned dose level. The temporal exposure pattern exhibits drastic fluctuations in dose rate at a given coordinate and within a single treatment session because of the discontinuous and repeated source movement into the target volume. This could potentially affect biological response. Therefore, mammalian cells were exposed as monolayers to a high dose rate 192Ir source by utilizing a dedicated irradiation device where the distance between a planar array of radioactive source positions and the plane of the cell monolayer could be varied from 2.5 mm to 40 mm, thus varying dose rate pattern for any chosen total dose. The Gammamed IIi afterloading system equipped with a nominal 370 GBq (10 Ci) 192-Ir source was used to irradiate V79 Chinese hamster lung fibroblasts from both confluent and from exponential growth phase with dose up to 12 Gy (at room temperature, total exposure not exceeding 1 h). For comparison, V79 cells were also exposed to 6 MV x-rays from a clinical linear accelerator (dose rate of 2.5 Gy min-1). As biological endpoint, cell survival was determined by standard colony forming assay. Dose measurements were conducted with a diamond detector (sensitive area 7.3 mm2), calibrated by means of 60Co radiation. Additionally, dose delivery was simulated by Monte Carlo calculations using the EGSnrc code system. The calculated secondary electron fluence spectra at the cell location did not indicate a significant change of radiation quality (i.e. higher linear energy transfer) at the lower distances. Clonogenic cell survival curves obtained after brachytherapy exhibited an altered biological response compared to x-rays which was characterized by a significant reduction of the survival curve shoulder when dose rate fluctuations were high. Therefore, also for the time scale of the present investigation, cellular effects of radiation are not invariant to the temporal pattern in dose rate. We propose that with high dose rate variation the cells activate less efficiently their DNA damage response than after continuous irradiation.

Deficit of heat shock transcription factor 1-heat shock 70 kDa protein 1A axis determines the cell death vulnerability in a model of spinocerebellar ataxia type 6.

PubMed

Li, Li; Saegusa, Hironao; Tanabe, Tsutomu

2009-11-01

Spinocerebellar ataxia type 6 (SCA6) is caused by a small expansion of polyglutamine (polyQ)-encoding CAG repeat in Ca(v)2.1 calcium channel gene. To gain insights into pathogenic mechanism of SCA6, we used HEK293 cells expressing fusion protein of enhanced green fluorescent protein and Ca(v)2.1 carboxyl terminal fragment (EGFP-Ca(v)2.1CT) [L24 and S13 cells containing 24 polyQ (disease range) and 13 polyQ (normal range), respectively] and examined their responses to some stressors. When exposed to CdCl(2), L24 cells showed lower viability than the control S13 cells and caspase-dependent apoptosis was enhanced more in L24 cells. Localization of EGFP-Ca(v)2.1CT was almost confined to the nucleus, where it existed as speckle-like structures. Interestingly, CdCl(2) treatment resulted in disruption of more promyelocytic leukemia nuclear bodies (PML-NBs) in L24 cells than in S13 cells and in cells where PML-NBs were disrupted, aggregates of EGFP-Ca(v)2.1CT became larger. Furthermore, a large number of aggregates were formed in L24 cells than in S13 cells. Results of RNAi experiments indicated that HSPA1A determined the difference against CdCl(2) toxicity. Furthermore, protein expression of heat shock transcription factor 1 (HSF1), which activates HSPA1A expression, was down-regulated in L24 cells. Therefore, HSF1-HSPA1A axis is critical for the vulnerability in L24 cells.

In vitro and in vivo genotoxicity investigations of differently sized amorphous SiO2 nanomaterials.

PubMed

Maser, Elena; Schulz, Markus; Sauer, Ursula G; Wiemann, Martin; Ma-Hock, Lan; Wohlleben, Wendel; Hartwig, Andrea; Landsiedel, Robert

2015-12-01

In vitro and in vivo genotoxic effects of differently sized amorphous SiO2 nanomaterials were investigated. In the alkaline Comet assay (with V79 cells), non-cytotoxic concentrations of 300 and 100-300μg/mL 15nm-SiO2 and 55nm-SiO2, respectively, relevant (at least 2-fold relative to the negative control) DNA damage. In the Alkaline unwinding assay (with V79 cells), only 15nm-SiO2 significantly increased DNA strand breaks (and only at 100μg/mL), whereas neither nanomaterial (up to 300μg/mL) increased Fpg (Formamidopyrimidine DNA glycosylase)-sensitive sites reflecting oxidative DNA base modifications. In the Comet assay using rat precision-cut lung slices, 15nm-SiO2 and 55nm-SiO2 induced significant DNA damage at ≥100μg/mL. In the Alkaline unwinding assay (with A549 cells), 30nm-SiO2 and 55nm-SiO2 (with larger primary particle size (PPS)) induced significant increases in DNA strand breaks at ≥50μg/mL, whereas 9nm-SiO2 and 15nm-SiO2 (with smaller PPS) induced significant DNA damage at higher concentrations. These two amorphous SiO2 also increased Fpg-sensitive sites (significant at 100μg/mL). In vivo, within 3 days after single intratracheal instillation of 360μg, neither 15nm-SiO2 nor 55nm-SiO2 caused genotoxic effects in the rat lung or in the bone marrow. However, pulmonary inflammation was observed in both test groups with findings being more pronounced upon treatment with 15nm-SiO2 than with 55nm-SiO2. Taken together, the study shows that colloidal amorphous SiO2 with different particle sizes may induce genotoxic effects in lung cells in vitro at comparatively high concentrations. However, the same materials elicited no genotoxic effects in the rat lung even though pronounced pulmonary inflammation evolved. This may be explained by the fact that a considerably lower dose reached the target cells in vivo than in vitro. Additionally, the different time points of investigation may provide more time for DNA damage repair after instillation. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

LcrV Mutants That Abolish Yersinia Type III Injectisome Function

PubMed Central

Ligtenberg, Katherine Given; Miller, Nathan C.; Mitchell, Anthony; Plano, Gregory V.

2013-01-01

LcrV, the type III needle cap protein of pathogenic Yersinia, has been proposed to function as a tether between YscF, the needle protein, and YopB-YopD to constitute the injectisome, a conduit for the translocation of effector proteins into host cells. Further, insertion of LcrV-capped needles from a calcium-rich environment into host cells may trigger the low-calcium signal for effector translocation. Here, we used a genetic approach to test the hypothesis that the needle cap responds to the low-calcium signal by promoting injectisome assembly. Growth restriction of Yersinia pestis in the absence of calcium (low-calcium response [LCR+] phenotype) was exploited to isolate dominant negative lcrV alleles with missense mutations in its amber stop codon (lcrV*327). The addition of at least four amino acids or the eight-residue Strep tag to the C terminus was sufficient to generate an LCR− phenotype, with variant LcrV capping type III needles that cannot assemble the YopD injectisome component. The C-terminal Strep tag appears buried within the cap structure, blocking effector transport even in Y. pestis yscF variants that are otherwise calcium blind, a constitutive type III secretion phenotype. Thus, LcrV*327 mutants arrest the needle cap in a state in which it cannot respond to the low-calcium signal with either injectisome assembly or the activation of type III secretion. Insertion of the Strep tag at other positions of LcrV produced variants with wild-type LCR+, LCR−, or dominant negative LCR− phenotypes, thereby allowing us to identify discrete sites within LcrV as essential for its attributes as a secretion substrate, needle cap, and injectisome assembly factor. PMID:23222719

A transcriptionally active estrogen receptor mutant is a novel type of dominant negative inhibitor of estrogen action.

PubMed

McInerney, E M; Ince, B A; Shapiro, D J; Katzenellenbogen, B S

1996-12-01

We have characterized a human estrogen receptor (ER) mutant, V364E, which has a single amino acid substitution in its hormone-binding domain. This ER mutant is fully active or even superactive at saturating levels of estradiol (10(-8) M E2) yet has the capacity to act as a strong dominant negative inhibitor of the wild type ER. In transient transfection assays using ER-negative Chinese hamster ovary (CHO) cells and two different estrogen response element (ERE)-containing promoter reporter genes, V364E treated with 10(-8) M E2 exhibited approximately 250% and 100% of the activity of the wild type ER with these two promoter contexts, respectively. Despite the high activity of V364E when present alone in cells, coexpression of both V364E and wild type ER causes a significant decrease in overall ER-mediated transcriptional activity. On the TATA promoter, where V364E was more inhibitory, estrogen-stimulated activity was reduced by approximately 50% at a 1:1 ratio of mutant to wild type ER expression vector, and at a 10:1 ratio, 75% of ER activity was inhibited. V364E was expressed at lower levels than wild type ER and has a approximately 40-fold lower affinity for E2 compared with wild type ER. In promoter interference assays, V364E exhibited a strict dependence upon E2 for binding to an ERE. Surprisingly, even when V364E was unable to bind to ERE DNA (i.e. either at low E2 concentration or by mutation of its DNA-binding domain), this mutant retained full dominant negative activity. This highly active ER mutant is, thus, able to repress ER-mediated transcription when the mutant and wild type ER are present together in cells, even without DNA binding. Since competition for ERE binding and the formation of inactive heterodimers cannot fully account for the dominant negative activity of V364E, it is probable that altered interactions with proteins important in ER-mediated transcription play a key role in the repression of transcription by V364E. The properties and probable mechanism of action of V364E distinguish it from other previously described dominant negative inhibitors, in which competition for cis-acting DNA elements by transcriptionally inactive receptors played a large role in the resultant dominant negative phenotype.

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Ho-Myoung; Kim, Hee-Dong; Kim, Tae Geun, E-mail: tgkim1@korea.ac.kr

Graphical abstract: The degradation tendency extracted by CP technique was almost the same in both the bulk-type and TFT-type cells. - Highlights: • D{sub it} is directly investigated from bulk-type and TFT-type CTF memory. • Charge pumping technique was employed to analyze the D{sub it} information. • To apply the CP technique to monitor the reliability of the 3D NAND flash. - Abstract: The energy distribution and density of interface traps (D{sub it}) are directly investigated from bulk-type and thin-film transistor (TFT)-type charge trap flash memory cells with tunnel oxide degradation, under program/erase (P/E) cycling using a charge pumping (CP)more » technique, in view of application in a 3-demension stackable NAND flash memory cell. After P/E cycling in bulk-type devices, the interface trap density gradually increased from 1.55 × 10{sup 12} cm{sup −2} eV{sup −1} to 3.66 × 10{sup 13} cm{sup −2} eV{sup −1} due to tunnel oxide damage, which was consistent with the subthreshold swing and transconductance degradation after P/E cycling. Its distribution moved toward shallow energy levels with increasing cycling numbers, which coincided with the decay rate degradation with short-term retention time. The tendency extracted with the CP technique for D{sub it} of the TFT-type cells was similar to those of bulk-type cells.« less

A Cytotoxic Type III Secretion Effector of Vibrio parahaemolyticus Targets Vacuolar H+-ATPase Subunit c and Ruptures Host Cell Lysosomes

PubMed Central

Matsuda, Shigeaki; Okada, Natsumi; Kodama, Toshio; Honda, Takeshi; Iida, Tetsuya

2012-01-01

Vibrio parahaemolyticus is one of the human pathogenic vibrios. During the infection of mammalian cells, this pathogen exhibits cytotoxicity that is dependent on its type III secretion system (T3SS1). VepA, an effector protein secreted via the T3SS1, plays a major role in the T3SS1-dependent cytotoxicity of V. parahaemolyticus. However, the mechanism by which VepA is involved in T3SS1-dependent cytotoxicity is unknown. Here, we found that protein transfection of VepA into HeLa cells resulted in cell death, indicating that VepA alone is cytotoxic. The ectopic expression of VepA in yeast Saccharomyces cerevisiae interferes with yeast growth, indicating that VepA is also toxic in yeast. A yeast genome-wide screen identified the yeast gene VMA3 as essential for the growth inhibition of yeast by VepA. Although VMA3 encodes subunit c of the vacuolar H+-ATPase (V-ATPase), the toxicity of VepA was independent of the function of V-ATPases. In HeLa cells, knockdown of V-ATPase subunit c decreased VepA-mediated cytotoxicity. We also demonstrated that VepA interacted with V-ATPase subunit c, whereas a carboxyl-terminally truncated mutant of VepA (VepAΔC), which does not show toxicity, did not. During infection, lysosomal contents leaked into the cytosol, revealing that lysosomal membrane permeabilization occurred prior to cell lysis. In a cell-free system, VepA was sufficient to induce the release of cathepsin D from isolated lysosomes. Therefore, our data suggest that the bacterial effector VepA targets subunit c of V-ATPase and induces the rupture of host cell lysosomes and subsequent cell death. PMID:22829766

Origin of Photovoltage Enhancement via Interfacial Modification with Silver Nanoparticles Embedded in an a-SiC:H p-Type Layer in a-Si:H Solar Cells.

PubMed

Li, Tiantian; Zhang, Qixing; Ni, Jian; Huang, Qian; Zhang, Dekun; Li, Baozhang; Wei, Changchun; Yan, Baojie; Zhao, Ying; Zhang, Xiaodan

2017-03-29

We used silver nanoparticles (Ag-NPs) embedded in the p-type semiconductor layer of hydrogenated amorphous silicon (a-Si:H) solar cells in the Schottky barrier contact design to modify the interface between aluminum-doped ZnO (ZnO:Al, AZO) and p-type hydrogenated amorphous silicon carbide (p-a-SiC:H) without plasmonic absorption. The high work function of the Ag-NPs provided a good channel for the transport of photogenerated holes. A p-type nanocrystalline SiC:H layer was used to compensate for the real surface defects and voids on the surface of Ag-NPs to reduce recombination at the AZO/p-type layer interface, which then enhanced the photovoltage of single-junction a-Si:H solar cells to values as high as 1.01 V. The Ag-NPs were around 10 nm in diameter and thermally stable in the p-type a-SiC:H film at the solar-cell process temperature. We will also show that a wide range of photovoltages between 1.01 and 2.89 V could be obtained with single-, double-, and triple-junction solar cells based on the single-junction a-Si:H solar cells with tunable high photovoltage. These solar cells are suitable photocathodes for solar water-splitting applications.

Manipulation of intestinal epithelial cell function by the cell contact-dependent type III secretion systems of Vibrio parahaemolyticus

PubMed Central

O'Boyle, Nicky; Boyd, Aoife

2013-01-01

Vibrio parahaemolyticus elicits gastroenteritis by deploying Type III Secretion Systems (TTSS) to deliver effector proteins into epithelial cells of the human intestinal tract. The bacteria must adhere to the human cells to allow colonization and operation of the TTSS translocation apparatus bridging the bacterium and the host cell. This article first reviews recent advances in identifying the molecules responsible for intercellular adherence. V. parahaemolyticus possesses two TTSS, each of which delivers an exclusive set of effectors and mediates unique effects on the host cell. TTSS effectors primarily target and alter the activation status of host cell signaling proteins, thereby bringing about changes in the regulation of cellular behavior. TTSS1 is responsible for the cytotoxicity of V. parahaemolyticus, while TTSS2 is necessary for the enterotoxicity of the pathogen. Recent publications have elucidated the function of several TTSS effectors and their importance in the virulence of the bacterium. This review will explore the ability of the TTSS to manipulate activities of human intestinal cells and how this modification of cell function favors bacterial colonization and persistence of V. parahaemolyticus in the host. PMID:24455490

Protection by beverages, fruits, vegetables, herbs, and flavonoids against genotoxicity of 2-acetylaminofluorene and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in metabolically competent V79 cells.

PubMed

Edenharder, R; Sager, J W; Glatt, H; Muckel, E; Platt, K L

2002-11-26

Chinese hamster lung fibroblasts, genetically engineered for the expression of rat cytochrome P450 dependent monooxygenase 1A2 and rat sulfotransferase 1C1 (V79-rCYP1A2-rSULT1C1 cells), were utilized to check for possible protective effects of beverages of plant origin, fruits, vegetables, and spices against genotoxicity induced by 2-acetylaminofluorene (AAF) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Antigenotoxic activities of juices from spinach and red beets against AAF could be monitored with similar effectivity by the HPRT-mutagenicity test (IC(50)=0.64%; 2.57%) and alkaline single cell gel electrophoresis (comet assay; IC(50)=0.12%; 0.89%) which detects DNA strand breaks and abasic sites. Applying the comet assay, genotoxicity of PhIP could, however, be demonstrated only in the presence of hydroxyurea and 1-[beta-D-arabinofuranosyl]cytosine, known inhibitors of DNA repair synthesis. As expected, AAF and PhIP were unable to induce any genotoxic effects in the parent V79 cells. Genotoxic activity of PhIP was strongly reduced in a dose-related manner by green tea and red wine, by blueberries, blackberries, red grapes, kiwi, watermelon, parsley, and spinach, while two brands of beer, coffee, black tea, rooibos tea, morellos, black-currants, plums, red beets, broccoli (raw and cooked), and chives were somewhat less active. One brand of beer was only moderately active while white wine, bananas, white grapes, and strawberries were inactive. Similarly, genotoxicity of AAF was strongly reduced by green, black, and rooibos tea, red wine, morellos, black-currants, kiwi, watermelon, and spinach while plums, red beets, and broccoli (raw) were less potent. Broccoli cooked exerted only moderate and white wine weak antigenotoxic activity. With respect to the possible mechanism(s) of inhibition of genotoxicity, benzo[a]pyrene-7,8-dihydrodiol (BaP-7,8-OH) and N-OH-PhIP were applied as substrates for the CYP1A family and for rSULT 1C1, respectively. Morellos, black-currants, and black tea strongly reduced the genotoxicity of BaP-7,8-OH, onions, rooibos tea, and red wine were less potent while red beets and spinach were inactive. On the other hand, red beets and spinach strongly inhibited the genotoxicity of N-OH-PhIP, rooibos tea was weakly active while all other items were inactive. These results are suggestive for enzyme inhibition as mechanism of protection by complex mixtures of plant origin. Taken together, our results demonstrate that protection by beverages, fruits, and vegetables against genotoxicity of heterocyclic aromatic amines may take place within metabolically competent mammalian cells as well as under the conditions of the Salmonella/reversion assay.

Two-Way Chemical Communication between Artificial and Natural Cells

PubMed Central

2017-01-01

Artificial cells capable of both sensing and sending chemical messages to bacteria have yet to be built. Here we show that artificial cells that are able to sense and synthesize quorum signaling molecules can chemically communicate with V. fischeri, V. harveyi, E. coli, and P. aeruginosa. Activity was assessed by fluorescence, luminescence, RT-qPCR, and RNA-seq. Two potential applications for this technology were demonstrated. First, the extent to which artificial cells could imitate natural cells was quantified by a type of cellular Turing test. Artificial cells capable of sensing and in response synthesizing and releasing N-3-(oxohexanoyl)homoserine lactone showed a high degree of likeness to natural V. fischeri under specific test conditions. Second, artificial cells that sensed V. fischeri and in response degraded a quorum signaling molecule of P. aeruginosa (N-(3-oxododecanoyl)homoserine lactone) were constructed, laying the foundation for future technologies that control complex networks of natural cells. PMID:28280778

Two Herbivore-Induced Cytochrome P450 Enzymes CYP79D6 and CYP79D7 Catalyze the Formation of Volatile Aldoximes Involved in Poplar Defense[C][W

PubMed Central

Irmisch, Sandra; Clavijo McCormick, Andrea; Boeckler, G. Andreas; Schmidt, Axel; Reichelt, Michael; Schneider, Bernd; Block, Katja; Schnitzler, Jörg-Peter; Gershenzon, Jonathan; Unsicker, Sybille B.; Köllner, Tobias G.

2013-01-01

Aldoximes are known as floral and vegetative plant volatiles but also as biosynthetic intermediates for other plant defense compounds. While the cytochrome P450 monooxygenases (CYP) from the CYP79 family forming aldoximes as biosynthetic intermediates have been intensively studied, little is known about the enzymology of volatile aldoxime formation. We characterized two P450 enzymes, CYP79D6v3 and CYP79D7v2, which are involved in herbivore-induced aldoxime formation in western balsam poplar (Populus trichocarpa). Heterologous expression in Saccharomyces cerevisiae revealed that both enzymes produce a mixture of different aldoximes. Knockdown lines of CYP79D6/7 in gray poplar (Populus × canescens) exhibited a decreased emission of aldoximes, nitriles, and alcohols, emphasizing that the CYP79s catalyze the first step in the formation of a complex volatile blend. Aldoxime emission was found to be restricted to herbivore-damaged leaves and is closely correlated with CYP79D6 and CYP79D7 gene expression. The semi-volatile phenylacetaldoxime decreased survival and weight gain of gypsy moth (Lymantria dispar) caterpillars, suggesting that aldoximes may be involved in direct defense. The wide distribution of volatile aldoximes throughout the plant kingdom and the presence of CYP79 genes in all sequenced genomes of angiosperms suggest that volatile formation mediated by CYP79s is a general phenomenon in the plant kingdom. PMID:24220631

K-RAS(V12) Induces Autocrine Production of EGFR Ligands and Mediates Radioresistance Through EGFR-Dependent Akt Signaling and Activation of DNA-PKcs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minjgee, Minjmaa; Toulany, Mahmoud; Kehlbach, Rainer

2011-12-01

Purpose: It is known that postirradiation survival of tumor cells presenting mutated K-RAS is mediated through autocrine activation of epidermal growth factor receptor (EGFR). In this study the molecular mechanism of radioresistance of cells overexpressing mutated K-RAS(V12) was investigated. Methods and Materials: Head-and-neck cancer cells (FaDu) presenting wild-type K-RAS were transfected with empty vector or vector expressing mutated K-RAS(V12). The effect of K-RAS(V12) on autocrine production of EGFR ligands, activation of EGFR downstream pathways, DNA damage repair, and postirradiation survival was analyzed. Results: Conditioned medium collected from K-RAS(V12)-transfected cells enhanced activation of the phosphatidylinositol-3-kinase-Akt pathway and increased postirradiation survival ofmore » wild-type K-RAS parental cells when compared with controls. These effects were reversed by amphiregulin (AREG)-neutralizing antibody. In addition, secretion of the EGFR ligands AREG and transforming growth factor {alpha} was significantly increased upon overexpression of K-RAS(V12). Expression of mutated K-RAS(V12) resulted in an increase in radiation-induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation at S2056. This increase was accompanied by increased repair of DNA double-strand breaks. Abrogation of DNA-PKcs phosphorylation by serum depletion or AREG-neutralizing antibody underscored the role of autocrine production of EGFR ligands, namely, AREG, in regulating DNA-PKcs activation in K-RAS mutated cells. Conclusions: These data indicate that radioresistance of K-RAS mutated tumor cells is at least in part due to constitutive production of EGFR ligands, which mediate enhanced repair of DNA double-strand breaks through the EGFR-phosphatidylinositol-3-kinase-Akt cascade.« less

Randomized Trial Comparing R-CHOP Versus High-Dose Sequential Chemotherapy in High-Risk Patients With Diffuse Large B-Cell Lymphomas.

PubMed

Cortelazzo, Sergio; Tarella, Corrado; Gianni, Alessandro Massimo; Ladetto, Marco; Barbui, Anna Maria; Rossi, Andrea; Gritti, Giuseppe; Corradini, Paolo; Di Nicola, Massimo; Patti, Caterina; Mulé, Antonino; Zanni, Manuela; Zoli, Valerio; Billio, Atto; Piccin, Andrea; Negri, Giovanni; Castellino, Claudia; Di Raimondo, Francesco; Ferreri, Andrés J M; Benedetti, Fabio; La Nasa, Giorgio; Gini, Guido; Trentin, Livio; Frezzato, Maurizio; Flenghi, Leonardo; Falorio, Simona; Chilosi, Marco; Bruna, Riccardo; Tabanelli, Valentina; Pileri, Stefano; Masciulli, Arianna; Delaini, Federica; Boschini, Cristina; Rambaldi, Alessandro

2016-11-20

Purpose The benefit of high-dose chemotherapy with autologous stem-cell transplantation (ASCT) as first-line treatment in patients with diffuse large B-cell lymphomas is still a matter of debate. To address this point, we designed a randomized phase III trial to compare rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-14 (eight cycles) with rituximab plus high-dose sequential chemotherapy (R-HDS) with ASCT. Patients and Methods From June 2005 to June 2011, 246 high-risk patients with a high-intermediate (56%) or high (44%) International Prognostic Index score were randomly assigned to the R-CHOP or R-HDS arm, and 235 were analyzed by intent to treat. The primary efficacy end point of the study was 3-year event-free survival, and results were analyzed on an intent-to-treat basis. Results Clinical response (complete response, 78% v 76%; partial response, 5% v 9%) and failures (no response, 15% v 11%; and early treatment-related mortality, 2% v 3%) were similar after R-CHOP versus R-HDS, respectively. After a median follow-up of 5 years, the 3-year event-free survival was 62% versus 65% ( P = .83). At 3 years, compared with the R-CHOP arm, the R-HDS arm had better disease-free survival (79% v 91%, respectively; P = .034), but this subsequently vanished because of late-occurring treatment-related deaths. No difference was detected in terms of progression-free survival (65% v 75%, respectively; P = .12), or overall survival (74% v 77%, respectively; P = .64). Significantly higher hematologic toxicity ( P < .001) and more infectious complications ( P < .001) were observed in the R-HDS arm. Conclusion In this study, front-line intensive R-HDS chemotherapy with ASCT did not improve the outcome of high-risk patients with diffuse large B-cell lymphomas.

Alteration of complex sphingolipid composition and its physiological significance in yeast Saccharomyces cerevisiae lacking vacuolar ATPase.

PubMed

Tani, Motohiro; Toume, Moeko

2015-12-01

In the yeast Saccharomyces cerevisiae, complex sphingolipids have three types of polar head group and five types of ceramide; however, the physiological significance of the structural diversity is not fully understood. Here, we report that deletion of vacuolar H+-ATPase (V-ATPase) in yeast causes dramatic alteration of the complex sphingolipid composition, which includes decreases in hydroxylation at the C-4 position of long-chain bases and the C-2 position of fatty acids in the ceramide moiety, decreases in inositol phosphorylceramide (IPC) levels, and increases in mannosylinositol phosphorylceramide (MIPC) and mannosyldiinositol phosphorylceramide [M(IP)2C] levels. V-ATPase-deleted cells exhibited slow growth at pH 7.2, whereas the increase in MIPC levels was significantly enhanced when V-ATPase-deleted cells were incubated at pH 7.2. The protein expression levels of MIPC and M(IP)2C synthases were significantly increased in V-ATPase-deleted cells incubated at pH 7.2. Loss of MIPC synthesis or an increase in the hydroxylation level of the ceramide moiety of sphingolipids on overexpression of Scs7 and Sur2 sphingolipid hydroxylases enhanced the growth defect of V-ATPase-deleted cells at pH 7.2. On the contrary, the growth rate of V-ATPase-deleted cells was moderately increased on the deletion of SCS7 and SUR2. In addition, supersensitivities to Ca2+, Zn2+ and H2O2, which are typical phenotypes of V-ATPase-deleted cells, were enhanced by the loss of MIPC synthesis. These results indicate the possibility that alteration of the complex sphingolipid composition is an adaptation mechanism for a defect of V-ATPase.

Combinatorial BTK and MALT1 inhibition augments killing of CD79 mutant diffuse large B cell lymphoma

PubMed Central

Nagel, Daniel; Bognar, Miriam; Eitelhuber, Andrea C.; Kutzner, Kerstin; Vincendeau, Michelle; Krappmann, Daniel

2015-01-01

Survival of activated B cell-subtype (ABC) of diffuse large B cell lymphoma (DLBCL) is driven by chronic B cell receptor (BCR) signaling that activates the canonical NF-κB pathway. Inhibition of BTK by Ibrutinib has been shown to kill ABC DLBCL cells that carry activating mutations in the BCR adaptor CD79. However, mutations in BTK or in downstream components such as CARMA1/CARD11 can render lymphomas Ibrutinib resistant. Therefore, we assessed here the simultaneous inhibition of BTK and the protease MALT1 that acts downstream of CARMA1 and is essential for ABC DLBCL tumor growth. We show that in CD79 mutant cells BTK is a crucial upstream regulator of MALT1, but dispensable in CARMA1 mutant ABC DLBCL. Combined inhibition of BTK by Ibrutinib and MALT1 by S-Mepazine additively impaired MALT1 cleavage activity and expression of NF-κB pro-survival factors. Thereby, combinatorial Ibrutinib and S-Mepazine treatment enhanced killing of CD79 mutant ABC DLBCL cells. Moreover, while expression of oncogenic CARMA1 in CD79 mutant cells conferred Ibrutinib resistance, double mutant cells were still sensitive to MALT1 inhibition by S-Mepazine. Thus, based on the genetic background combinatorial BTK and MALT1 inhibition may improve effectiveness of therapeutic treatment and reduce the chances for the development of drug resistances. PMID:26540570

Anti-CD22 and anti-CD79B antibody drug conjugates are active in different molecular diffuse large B-cell lymphoma subtypes.

PubMed

Pfeifer, M; Zheng, B; Erdmann, T; Koeppen, H; McCord, R; Grau, M; Staiger, A; Chai, A; Sandmann, T; Madle, H; Dörken, B; Chu, Y-W; Chen, A I; Lebovic, D; Salles, G A; Czuczman, M S; Palanca-Wessels, M C; Press, O W; Advani, R; Morschhauser, F; Cheson, B D; Lenz, P; Ott, G; Polson, A G; Mundt, K E; Lenz, G

2015-07-01

Antibody drug conjugates (ADCs), in which cytotoxic drugs are linked to antibodies targeting antigens on tumor cells, represent promising novel agents for the treatment of malignant lymphomas. Pinatuzumab vedotin is an anti-CD22 ADC and polatuzumab vedotin an anti-CD79B ADC that are both linked to the microtubule-disrupting agent monomethyl auristatin E (MMAE). In the present study, we analyzed the activity of these agents in different molecular subtypes of diffuse large B-cell lymphoma (DLBCL) both in vitro and in early clinical trials. Both anti-CD22-MMAE and anti-CD79B-MMAE were highly active and induced cell death in the vast majority of activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL cell lines. Similarly, both agents induced cytotoxicity in models with and without mutations in the signaling molecule CD79B. In line with these observations, relapsed and refractory DLBCL patients of both subtypes responded to these agents. Importantly, a strong correlation between CD22 and CD79B expression in vitro and in vivo was not detectable, indicating that patients should not be excluded from anti-CD22-MMAE or anti-CD79B-MMAE treatment because of low target expression. In summary, these studies suggest that pinatuzumab vedotin and polatuzumab vedotin are active agents for the treatment of patients with different subtypes of DLBCL.

Molecular determinants of the V3 loop of human immunodeficiency virus type 1 glycoprotein gp120 responsible for controlling cell tropism.

PubMed

Chavda, S C; Griffin, P; Han-Liu, Z; Keys, B; Vekony, M A; Cann, A J

1994-11-01

We and others have identified the major determinant of cell tropism in human immunodeficiency virus type 1 (HIV-1) as the V3 loop of glycoprotein gp120. We have conducted a detailed study of two molecularly cloned isolates of HIV-1, HIVJR-CSF and HIVNL4-3, that differ in their tropism for immortalized CD4+ cell lines, by constructing a series of site-directed mutations within the V3 loop of HIVJR-CSF based on the sequence of HIVNL4-3. The phenotypes of these mutants fall into two classes, those which are viable and those which are not. A spontaneous mutant with significantly altered growth properties was also recovered and found to have an additional single amino acid change in the V3 loop sequence. The carboxy-terminal beta-strand part of the V3 loop is the major determinant of cell tropism. However, the results presented here indicate that the functional role of the V3 loop sequences can only be interpreted properly in the context of the original gp120 backbone from which they were derived. These findings show that over-simplistic interpretation of sequence data derived from unknown mixtures of HIV variants in infected persons may be highly misleading.

Unique variations of Epstein-Barr virus-encoded BARF1 gene in nasopharyngeal carcinoma biopsies.

PubMed

Wang, Yun; Wang, Xiao-Feng; Sun, Zhi-Fu; Luo, Bing

2012-06-01

The Epstein-Barr virus (EBV) BamHI-A rightward frame 1 (BARF1) gene is frequently expressed in EBV-associated epithelial malignancies and involves in oncogenicity and immunomodulation. To characterize the variations of BARF1 gene in different populations, the sequences of BARF1 gene in Northern Chinese nasopharyngeal carcinoma (NPC), EBV-associated gastric carcinoma (EBVaGC) and healthy donors were analyzed. The correlation of BARF1 variation with polymorphisms of BamHI F fragment (type F and f variants) and EBV-coded viral interleukin-10 (vIL-10) gene (B95-8 and SPM patterns) was also explored. Two major subtypes of BARF1 gene, designated as B95-8 and V29A, were identified. B95-8 subtype had identical amino acid sequence to B95-8 and was the dominant subtype among the EBV isolates from Northern China. V29A subtype, with one consistent amino acid change at residue 29 (V→A) and several nucleotide changes, showed higher frequency in NPC cases (25.3%, 20/79) than in EBVaGC cases (0/45) or healthy donors (4.3%, 2/46) (NPC vs. EBVaGC: P=0.0001; NPC vs. healthy donor: P=0.004). A preferential linkage between BamHI F and BARF1/vIL-10 polymorphisms was found. Type f isolates was specially correlated with the V29A/SPM genotype in NPC isolates and type f/V29A/SPM was preferentially found in NPC. BARF1/c-fms homology domain, transforming domain and cytotoxic T lymphocyte (CTL) epitopes of BARF1 were highly conserved in most isolates, suggesting the important role of BARF1 in virus infection and the potential usefulness in EBV-targeting immunotherapy of EBV-associated tumors. The relatively higher prevalence of type f/V29A/SPM strains in NPC may also suggest the association between these variations in multiple viral genes and NPC. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular epidemiology of enterovirus and parechovirus infections according to patient age over a 4-year period in Spain.

PubMed

Cabrerizo, María; Díaz-Cerio, María; Muñoz-Almagro, Carmen; Rabella, Núria; Tarragó, David; Romero, María Pilar; Pena, María José; Calvo, Cristina; Rey-Cao, Sonia; Moreno-Docón, Antonio; Martínez-Rienda, Inés; Otero, Almudena; Trallero, Gloria

2017-03-01

The epidemiology and clinical association of enterovirus (EV) and parechovirus (HPeV) infections, as well as the type-distribution-according-to-age, were determined during a 4-year study period in Spain. During 2010-2013, a total of 21,832 clinical samples were screened for EV and the detection frequency was 6.5% (1,430). Of the total EV-negative samples, only 1,873 samples from 2011 to 2013 were available for HPeV testing. HPeV was detected in 42 (2%) of them. Positive samples were genotyped using PCR and sequencing. EV infections occurred in all age groups of patients: neonates (17%), children 28 days to 2 years (29%), children 2-14 years (40%), and adults (14%). Thirty-four different EV types were identified. HPeV infections were detected exclusively in infants <8 m (70% neonates, P < 0.05). All but one HPeV were HPeV-3. Differences in type frequency detection were found according to age and clinical manifestation. Coxsackievirus (CV)-B4 (61%), CV-B5 (83%), and HPeV-3 (64%) were more frequent in neonates than in older patients (P < 0.05). Echovirus (E)-3 (60%), E-18 (47%), E-25 (62%), CV-A6 (61%), CV-A16 (72%), and EV-71 (75%) were mainly detected in children 28 days to 2 years (P < 0.05), whereas, E-6 (79%), E-20 (88%), and E-30 (85%) were predominant in children >2 years and adults (P < 0.05). Clinically, meningitis was associated with EV (P < 0.01) whereas, encephalitis was more frequent in HPeV-infected patients. CV-B types were associated with myocarditis (90%; P < 0.05) and EV species A with hand-foot-mouth-disease/atypical exanthema (88%; P < 0.05). J. Med. Virol. 89:435-442, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Hydroethidine: a fluorescent redox probe for locating hypoxic cells in spheroids and murine tumours.

PubMed

Olive, P L

1989-09-01

The fluorescent redox probe hydroethidine was accumulated and metabolised about five times faster in aerobic than in hypoxic mammalian cells. Patterns of fluorescence in Chinese hamster V79 spheroids also indicated that internal hypoxic cells were less able to metabolise the drug; toxicity was observed in cells only when cell fluorescence exceeded about 500 times background. In medium equilibrated with air or nitrogen, cell accumulation of the stain was rapid, and began to plateau after 30 min; loss of ethidium was initially rapid, with a slower component after 30 min, and transfer of the metabolite ethidium between stained and unstained cells was observed after 2 h co-incubation. Sorting cells from irradiated spheroids on the basis of ethidium fluorescence provided good separation of aerobic radiosensitive and hypoxic radioresistant cells, although separation using the perfusion probe, Hoechst 33342, was superior. Similar experiments with the murine SCCVII squamous cell carcinoma suggested that hydroethidine might be a useful indirect stain for locating hypoxic cells in experimental tumours when used in combination with a perfusion probe such as Hoechst 33342.

Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus

PubMed Central

Gao, Xiang; Esseili, Malak A.; Lu, Zhongyan; Saif, Linda J.

2016-01-01

ABSTRACT Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. IMPORTANCE Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new information needed for developing potential inhibitors to block binding and prevent contamination. PMID:26969699

Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus.

PubMed

Gao, Xiang; Esseili, Malak A; Lu, Zhongyan; Saif, Linda J; Wang, Qiuhong

2016-05-15

Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new information needed for developing potential inhibitors to block binding and prevent contamination. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Radioprotective Thiolamines WR-1065 and WR-33278 Selectively Denature Nonhistone Nuclear Proteins

NASA Technical Reports Server (NTRS)

Booth, Valerie K.; Roberts, Jeanette C.; Warters, Raymond L.; Wilmore, Britta H.; Lepock, James R.

2000-01-01

Differential scanning calorimetry was used to study the interactions of nuclei isolated from Chinese hamster V79 cells with the radioprotector WR-1065, other thiol compounds, and polyamines. Differential scanning calorimetry monitors denaturation of macromolecules and resolves the major nuclear components (e.g. constrained and relaxed DNA, nucleosome core, and nuclear matrix) of intact nuclei on the basis of thermal stability. WR-1065 treatment (0.5-10 mM) of isolated nuclei led to the irreversible denaturation of nuclear proteins, a fraction of which are nuclear matrix proteins. Denaturation of 50% of the total nonhistone nuclear protein content of isolated nuclei occurred after exposure to 4.7 mM WR-1065 for 20 min at 23 C. In addition, a 22% increase in the insoluble protein content of nuclei isolated from V79 cells that had been treated with 4 mM WR-1065 for 30 min at 37 C was observed, indicating that WR-1065-induced protein denaturation occurs not only in isolated nuclei but also in the nuclei of intact cells. From the extent of the increase in insoluble protein in the nucleus, protein denaturation by WR-1065 is expected to contribute to drug toxicity at concentrations greater than approximately 4 mM. WR-33278, the disulfide form of WR1065, was approximately twice as effective as the free thiol at denaturing nuclear proteins. The proposed mechanism for nucleoprotein denaturation is through direct interactions with protein cysteine groups with the formation of destabilizing protein-WR-1065 disulfides. In comparison to its effect on nuclear proteins in isolated nuclei, WR-1065 had only a very small effect on non-nuclear proteins of whole cells, isolated nuclear matrix, or the thiol-rich Ca (2+) ATPase of sarcoplasmic reticulum, indicating that WR-1065 can effectively denature protein only inside an intact nucleus, probably due to the increased concentration of the positively charged drug in the vicinity of DNA.

Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line

PubMed Central

Senevirathne, Mahinda; Kim, Soo-Hyun

2010-01-01

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H2O2-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against H2O2-induced cell damage in vitro. PMID:20607062

Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line.

PubMed

Senevirathne, Mahinda; Kim, Soo-Hyun; Jeon, You-Jin

2010-06-01

Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H(2)O(2)-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher cell viability and ROS scavenging activities, and hence, selected for further antioxidant assays. Both AMG and Alcalase hydrolysates also showed higher protective effects against lipid peroxidation, DNA damage and apoptotic body formation in a dose-dependent fashion. Thus, the results indicated that water soluble compounds obtained by enzymatic hydrolysis of blueberry possess good antioxidant activity against H(2)O(2)-induced cell damage in vitro.

Characterization of a 3rd Generation Lentiviral Vector Pseudotyped With Nipah Virus Envelope Proteins For Endothelial Cell Transduction

PubMed Central

Witting, Scott R.; Vallanda, Priya; Gamble, Aisha L.

2013-01-01

Lentiviruses are becoming progressively more popular as gene therapy vectors due to their ability to integrate into quiescent cells and recent clinical trial successes. Directing these vectors to specific cell types and limiting off-target transduction in vivo remains a challenge. Replacing the viral envelope proteins responsible for cellular binding, or pseudotyping, remains a common method to improve lentiviral targeting. Here, we describe the development of a high titer, 3rd generation lentiviral vector pseudotyped with Nipah virus fusion protein (NiV-F) and attachment protein (NiV-G). Critical to high titers was truncation of the cytoplasmic domains of both NiV-F and NiV-G. As known targets of wild-type Nipah virus, primary endothelial cells are shown to be effectively transduced by the Nipah pseudotype. In contrast, human CD34+ hematopoietic progenitors were not significantly transduced. Additionally, the Nipah pseudotype has increased stability in human serum compared to VSV pseudotyped lentivirus. These findings suggest that the use of Nipah virus envelope proteins in 3rd generation lentiviral vectors would be a valuable tool for gene delivery targeted to endothelial cells. PMID:23698741

Characterization of a third generation lentiviral vector pseudotyped with Nipah virus envelope proteins for endothelial cell transduction.

PubMed

Witting, S R; Vallanda, P; Gamble, A L

2013-10-01

Lentiviruses are becoming progressively more popular as gene therapy vectors due to their ability to integrate into quiescent cells and recent clinical trial successes. Directing these vectors to specific cell types and limiting off-target transduction in vivo remains a challenge. Replacing the viral envelope proteins responsible for cellular binding, or pseudotyping, remains a common method to improve lentiviral targeting. Here, we describe the development of a high titer, third generation lentiviral vector pseudotyped with Nipah virus fusion protein (NiV-F) and attachment protein (NiV-G). Critical to high titers was truncation of the cytoplasmic domains of both NiV-F and NiV-G. As known targets of wild-type Nipah virus, primary endothelial cells are shown to be effectively transduced by the Nipah pseudotype. In contrast, human CD34+ hematopoietic progenitors were not significantly transduced. Additionally, the Nipah pseudotype has increased stability in human serum compared with vesicular stomatitis virus pseudotyped lentivirus. These findings suggest that the use of Nipah virus envelope proteins in third generation lentiviral vectors would be a valuable tool for gene delivery targeted to endothelial cells.

Expression, purification, crystallization and preliminary X-ray studies of Lactobacillus jensenii enolase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, Paul T.; Raghunathan, Kannan; Spurbeck, Rachel R.

2010-09-02

Recombinant Lactobacillus jensenii enolase fused to a C-terminal noncleavable His tag was expressed in Escherichia coli, purified and crystallized by sitting-drop vapor diffusion. A complete data set was collected to 3.25 {angstrom} resolution. The crystals belonged to space group I4, with unit-cell parameters a = b = 145.31, c = 99.79 {angstrom}. There were two protein subunits in the asymmetric unit, which gave a Matthews coefficient V{sub M} of 2.8 {angstrom}{sup 3} Da{sup -1}, corresponding to 55.2% solvent content.

Evaluation of a Collagen-Chitosan Hydrogel for Potential Use as a Pro-Angiogenic Site for Islet Transplantation

PubMed Central

McBane, Joanne E.; Vulesevic, Branka; Padavan, Donna T.; McEwan, Kimberly A.; Korbutt, Gregory S.; Suuronen, Erik J.

2013-01-01

Islet transplantation to treat type 1 diabetes (T1D) has shown varied long-term success, due in part to insufficient blood supply to maintain the islets. In the current study, collagen and collagen:chitosan (10:1) hydrogels, +/- circulating angiogenic cells (CACs), were compared for their ability to produce a pro-angiogenic environment in a streptozotocin-induced mouse model of T1D. Initial characterization showed that collagen-chitosan gels were mechanically stronger than the collagen gels (0.7kPa vs. 0.4kPa elastic modulus, respectively), had more cross-links (9.2 vs. 7.4/µm2), and were degraded more slowly by collagenase. After gelation with CACs, live/dead staining showed greater CAC viability in the collagen-chitosan gels after 18h compared to collagen (79% vs. 69%). In vivo, collagen-chitosan gels, subcutaneously implanted for up to 6 weeks in a T1D mouse, showed increased levels of pro-angiogenic cytokines over time. By 6 weeks, anti-islet cytokine levels were decreased in all matrix formulations ± CACs. The 6-week implants demonstrated increased expression of VCAM-1 in collagen-chitosan implants. Despite this, infiltrating vWF+ and CXCR4+ angiogenic cell numbers were not different between the implant types, which may be due to a delayed and reduced cytokine response in a T1D versus non-diabetic setting. The mechanical, degradation and cytokine data all suggest that the collagen-chitosan gel may be a suitable candidate for use as a pro-angiogenic ectopic islet transplant site. PMID:24204863

CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Heyu; Nan, Xu; Li, Xuefen

Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 wasmore » down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.« less

Potential for use of InP solar cells in the space radiation environment

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

Indium phosphide solar cells were observed to have significantly higher radiation resistance than either GaAs or Si after exposure to 10 MeV proton irradiation data and previous 1 MeV electron data together with projected efficiencies for InP, it was found that these latter cells produced more output power than either GaAs or Si after specified fluences of 10 MeV protons and 1 MeV electrons. Estimates of expected performance in a proton dominated space orbit yielded much less degradation for InP when compared to the remaining two cell types. It was concluded that, with additional development to increase efficiency, InP solar cells would perform significantly better than either GaAs or Si in the space radiation environment.

Potential for use of indium phosphide solar cells in the space radiation environment

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

Indium phosphide solar cells were observed to have significantly higher radiation resistance than either GaAs or Si after exposure to 10 MeV proton irradiation data and previous 1 MeV electron data together with projected efficiencies for InP, it was found that these latter cells produced more output power than either GaAs or Si after specified fluences of 10 MeV protons and 1 MeV electrons. Estimates of expected performance in a proton dominated space orbit yielded much less degradation for InP when compared to the remaining two cell types. It was concluded that, with additional development to increase efficiency, InP solar cells would perform significantly better than either GaAs or Si in the space radiation environment.

Early postnatal development of vasoactive intestinal polypeptide- and peptide histidine isoleucine-immunoreactive structures in the cat visual cortex.

PubMed

Wahle, P; Meyer, G

1989-04-08

The early postnatal development of neurons containing vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) has been analyzed in visual areas 17 and 18 of cats aged from postnatal day (P) 0 to adulthood. Neuronal types are established mainly by axonal criteria. Both peptides occur in the same neuronal types and display the same postnatal chronology of appearance. Several cell types are transient, which means that they are present in the cortex only for a limited period of development. According to their chronology of appearance the VIP/PHI-immunoreactive (ir) cell types are grouped into three neuronal populations. The first population comprises six cell types which appear early in postnatal life. The pseudohorsetail cells of layer I possess a vertically descending axon which initially gives rise to recurrent collaterals, then forms a bundle passing layers III to V, and finally, horizontal terminal fibers in layer VI. The neurons differentiate at P 4 and disappear by degeneration around P 30. The neurons with columnar dendritic fields of layers IV/V are characterized by a vertical arrangement of long dendrites ascending or descending parallel to each other, thus forming an up to 600 microns long dendritic column. Their axons always descend and terminate in broad fields in layer VI. The neurons appear at P 7 and are present until P 20. The multipolar neurons of layer VI occur in isolated positions and have broad axonal territories. The neurons differentiate at P 7 and persist into adulthood. Bitufted to multipolar neurons of layers II/III have axons descending as a single fiber to layer VI, where they terminate. The neurons appear at P 12 and persist into adulthood. The four cell types described above issue a vertically oriented fiber architecture in layers II-V and a horizontal terminal plexus in layer VI which is dense during the second, third and fourth week. Concurrent with the disappearance of the two transient types the number of descending axonal bundles and the density of the layer VI plexus is reduced, but the latter is maintained during adulthood by the two persisting cell types. Two further cell types belong to the first population: The transient bipolar cells of layers IV, V, and VI have long dendrites which extend through the entire cortical width. Their axons always descend, leave the gray matter, and apparently terminate in the upper white matter. The neurons differentiate concurrently with the pseudohorsetail cells at P 4, are very frequent during the following weeks, and eventually disappear at P 30.(ABSTRACT TRUNCATED AT 400 WORDS)

Diabetes and Neurodegeneration in Wolfram Syndrome

PubMed Central

Rohayem, Julia; Ehlers, Christian; Wiedemann, Bärbel; Holl, Reinhard; Oexle, Konrad; Kordonouri, Olga; Salzano, Giuseppina; Meissner, Thomas; Burger, Walter; Schober, Edith; Huebner, Angela; Lee-Kirsch, Min Ae

2011-01-01

OBJECTIVE To describe the diabetes phenotype in Wolfram syndrome compared with type 1 diabetes, to investigate the effect of glycemic control on the neurodegenerative process, and to assess the genotype-phenotype correlation. RESEARCH DESIGN AND METHODS The clinical data of 50 patients with Wolfram syndrome-related diabetes (WSD) were reviewed and compared with the data of 24,164 patients with type 1 diabetes. Patients with a mean HbA1c during childhood and adolescence of ≤7.5 and >7.5% were compared with respect to the occurrence of additional Wolfram syndrome symptoms. The wolframin (WFS1) gene was screened for mutations in 39 patients. WFS1 genotypes were examined for correlation with age at onset of diabetes. RESULTS WSD was diagnosed earlier than type 1 diabetes (5.4 ± 3.8 vs. 7.9 ± 4.2 years; P < 0.001) with a lower prevalence of ketoacidosis (7 vs. 20%; P = 0.049). Mean duration of remission in WSD was 2.3 ± 2.4 vs. 1.6 ± 2.1 in type 1 diabetes (NS). Severe hypoglycemia occurred in 37 vs. 7.9% (P < 0.001). Neurologic disease progression was faster in the WSD group with a mean HbA1c >7.5% (P = 0.031). Thirteen novel WSF1 mutations were identified. Predicted functional consequence of WFS1 mutations correlated with age at WSD onset (P = 0.028). CONCLUSIONS Endoplasmic reticulum stress–mediated decline of β-cells in WSD occurs earlier in life than autoimmune-mediated β-cell destruction in type 1 diabetes. This study establishes a role for WFS1 in determining the age at onset of diabetes in Wolfram syndrome and identifies glucose toxicity as an accelerating feature in the progression of disease. PMID:21602428

New clinicopathological associations and histoprognostic markers in ILAE types of hippocampal sclerosis.

PubMed

Calderon-Garcidueñas, Ana Laura; Mathon, Bertrand; Lévy, Pierre; Bertrand, Anne; Mokhtari, Karima; Samson, Véronique; Thuriès, Valérie; Lambrecq, Virginie; Nguyen, Vi-Huong Michel; Dupont, Sophie; Adam, Claude; Baulac, Michel; Clémenceau, Stéphane; Duyckaerts, Charles; Navarro, Vincent; Bielle, Franck

2018-02-24

Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a heterogeneous syndrome. Surgery results in seizure freedom for most pharmacoresistant patients, but the epileptic and cognitive prognosis remains variable. The 2013 International League Against Epilepsy (ILAE) histopathological classification of hippocampal sclerosis (HS) has fostered research to understand MTLE-HS heterogeneity. We investigated the associations between histopathological features (ILAE types, hypertrophic CA4 neurons, granule cell layer alterations, CD34 immunopositive cells) and clinical features (presurgical history, postsurgical outcome) in a monocentric series of 247 MTLE-HS patients treated by surgery. NeuN, GFAP and CD34 immunostainings and a double independent pathological examination were performed. 186 samples were type 1, 47 type 2, 7 type 3 and 7 samples were gliosis only but no neuronal loss (noHS). In the type 1, hypertrophic CA4 neurons were associated with a worse postsurgical outcome and granule cell layer duplication was associated with generalized seizures and episodes of status epilepticus. In the type 2, granule cell layer duplication was associated with generalized seizures. CD34+ stellate cells were more frequent in the type 2, type 3 and in noHS. These cells had a Nestin and SOX2 positive, immature neural immunophenotype. Patients with nodules of CD34+ cells had more frequent dysmnesic auras. CD34+ stellate cells in scarce pattern were associated with higher ratio of normal MRI and of stereo-electroencephalographic studies. CD34+ cells were associated with a trend for a better postsurgical outcome. Among CD34+ cases, we proposed a new entity of BRAF V600E positive HS and we described three hippocampal multinodular and vacuolating neuronal tumors. To conclude, our data identified new clinicopathological associations with ILAE types. They showed the prognostic value of CA4 hypertrophic neurons. They highlighted CD34+ stellate cells and BRAF V600E as biomarkers to further decipher MTLE-HS heterogeneity. © 2018 International Society of Neuropathology.

Device simulation of lead-free CH3NH3SnI3 perovskite solar cells with high efficiency

NASA Astrophysics Data System (ADS)

Du, Hui-Jing; Wang, Wei-Chao; Zhu, Jian-Zhuo

2016-10-01

The lead-free perovskite solar cells (PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite. CH3NH3SnI3 is a viable alternative to CH3NH3PbX3, because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite. The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CH3NH3SnI3 based cells greatly. In the paper, we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation. It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM, while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance. By further optimizing the parameters of the doping concentration (1.3× 1016 cm-3) and the defect density (1× 1015 cm-3) of perovskite absorption layer, and the electron affinity of buffer (4.0 eV) and HTM (2.6 eV), we finally obtain some encouraging results of the J sc of 31.59 mA/cm2, V oc of 0.92 V, FF of 79.99%, and PCE of 23.36%. The results show that the lead-free CH3NH3SnI3 PSC is a potential environmentally friendly solar cell with high efficiency. Improving the Sn2 + stability and reducing the defect density of CH3NH3SnI3 are key issues for the future research, which can be solved by improving the fabrication and encapsulation process of the cell. Project supported by the Graduate Student Education Teaching Reform Project, China (Grant No. JG201512) and the Young Teachers Research Project of Yanshan University, China (Grant No. 13LGB028).

Fiber type conversion alters inactivation of voltage-dependent sodium currents in murine C2C12 skeletal muscle cells.

PubMed

Zebedin, Eva; Sandtner, Walter; Galler, Stefan; Szendroedi, Julia; Just, Herwig; Todt, Hannes; Hilber, Karlheinz

2004-08-01

Each skeletal muscle of the body contains a unique composition of "fast" and "slow" muscle fibers, each of which is specialized for certain challenges. This composition is not static, and the muscle fibers are capable of adapting their molecular composition by altered gene expression (i.e., fiber type conversion). Whereas changes in the expression of contractile proteins and metabolic enzymes in the course of fiber type conversion are well described, little is known about possible adaptations in the electrophysiological properties of skeletal muscle cells. Such adaptations may involve changes in the expression and/or function of ion channels. In this study, we investigated the effects of fast-to-slow fiber type conversion on currents via voltage-gated Na+ channels in the C(2)C(12) murine skeletal muscle cell line. Prolonged treatment of cells with 25 nM of the Ca2+ ionophore A-23187 caused a significant shift in myosin heavy chain isoform expression from the fast toward the slow isoform, indicating fast-to-slow fiber type conversion. Moreover, Na+ current inactivation was significantly altered. Slow inactivation less strongly inhibited the Na+ currents of fast-to-slow fiber type-converted cells. Compared with control cells, the Na+ currents of converted cells were more resistant to block by tetrodotoxin, suggesting enhanced relative expression of the cardiac Na+ channel isoform Na(v)1.5 compared with the skeletal muscle isoform Na(v)1.4. These results imply that fast-to-slow fiber type conversion of skeletal muscle cells involves functional adaptation of their electrophysiological properties.

The silencing suppressor (NSs) protein of the plant virus Tomato spotted wilt virus enhances heterologous protein expression and baculovirus pathogenicity in cells and lepidopteran insects.

PubMed

de Oliveira, Virgínia Carla; da Silva Morgado, Fabricio; Ardisson-Araújo, Daniel Mendes Pereira; Resende, Renato Oliveira; Ribeiro, Bergmann Morais

2015-11-01

In this work, we showed that cell death induced by a recombinant (vAcNSs) Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing the silencing suppressor (NSs) protein of Tomato spotted wilt virus (TSWV) was enhanced on permissive and semipermissive cell lines. The expression of a heterologous gene (firefly luciferase) during co-infection of insect cells with vAcNSs and a second recombinant baculovirus (vAgppolhfluc) was shown to increase when compared to single vAgppolhfluc infections. Furthermore, the vAcNSs mean time-to-death values were significantly lower than those for wild-type AcMNPV on larvae of Spodoptera frugiperda and Anticarsia gemmatalis. These results showed that the TSWV-NSs protein could efficiently increase heterologous protein expression in insect cells as well as baculovirus pathogenicity and virulence, probably by suppressing the gene-silencing machinery in insects.

The Opportunistic Pathogen Vibrio vulnificus Produces Outer Membrane Vesicles in a Spatially Distinct Manner Related to Capsular Polysaccharide

PubMed Central

Hampton, Cheri M.; Guerrero-Ferreira, Ricardo C.; Storms, Rachel E.; Taylor, Jeannette V.; Yi, Hong; Gulig, Paul A.; Wright, Elizabeth R.

2017-01-01

Vibrio vulnificus, a bacterial species that inhabits brackish waters, is an opportunistic pathogen of humans. V. vulnificus infections can cause acute gastroenteritis, invasive septicemia, tissue necrosis, and potentially death. Virulence factors associated with V. vulnificus include the capsular polysaccharide (CPS), lipopolysaccharide, flagellum, pili, and outer membrane vesicles (OMVs). The aims of this study were to characterize the morphology of V. vulnificus cells and the formation and arrangement of OMVs using cryo-electron microscopy (cryo-EM). cryo-EM and cryo-electron tomography imaging of V. vulnificus strains grown in liquid cultures revealed the presence of OMVs (diameters of ∼45 nm for wild-type, ∼30 nm for the unencapsulated mutant, and ∼50 nm for the non-motile mutant) in log-phase growth. Production of OMVs in the stationary growth phase was limited and irregular. The spacing of the OMVs around the wild-type cells was in regular, concentric rings. In wild-type cells and a non-motile mutant, the spacing between the cell envelope and the first ring of OMVs was ∼200 nm; this spacing was maintained between subsequent OMV layers. The size, arrangement, and spacing of OMVs in an unencapsulated mutant was irregular and indicated that the polysaccharide chains of the capsule regulate aspects of OMV production and order. Together, our results revealed the distinctive organization of V. vulnificus OMVs that is affected by expression of the CPS. PMID:29163452

Stimulation of complement component C3 synthesis in macrophagelike cell lines by group B streptococci.

PubMed Central

Goodrum, K J

1987-01-01

Complement levels and complement activation are key determinants in streptococcus-induced inflammatory responses. Activation of macrophage functions, such as complement synthesis, by group B streptococci (GBS) was examined as a possible component of GBS-induced chronic inflammation. Using an enzyme-linked immunosorbent assay, secreted C3 from mouse macrophagelike cell lines (PU5-1.8 and J774A.1) was monitored after cultivation with GBS. Whole, heat-killed GBS (1 to 10 CFU per macrophage) of both type Ia and III strains induced 25 to 300% increases in secreted C3 in both cell lines after a 24-h cultivation. GBS-treated cell lines exhibited increases in secreted lysozyme (10%) and in cellular protein (25 to 50%). Inhibition of macrophage phagocytosis by cytochalasin B inhibited GBS stimulation of C3. Purified cell walls of GBS type III strain 603-79 (1 to 10 micrograms/ml) also enhanced C3 synthesis. Local enhancement of macrophage C3 production by ingested streptococci or by persistent cell wall antigens may serve to promote chronic inflammatory responses. PMID:3552987

X-ray flux variability of active galactic nuclei observed using NuSTAR

NASA Astrophysics Data System (ADS)

Rani, Priyanka; Stalin, C. S.; Rakshit, Suvendu

2017-04-01

We present results of a systematic study of flux variability on hourly time-scales in a large sample of active galactic nuclei (AGN) in the 3-79 keV band using data from Nuclear Spectroscopic Telescope Array. Our sample consists of four BL Lac objects (BL Lacs), three flat spectrum radio quasars (FSRQs) 24 Seyfert 1, 42 Seyfert 2 and eight narrow line Seyfert 1 (NLSy1) galaxies. We find that in the 3-79 keV band, about 65 per cent of the sources in our sample show significant variations on hourly time-scales. Using the Mann-Whitney U-test and the Kolmogorov-Smirnov test, we find no difference in the variability behaviour between Seyfert 1 and 2 galaxies. The blazar sources (FSRQs and BL Lacs) in our sample are more variable than Seyfert galaxies that include Seyfert 1 and Seyfert 2 in the soft (3-10 keV), hard (10-79 keV) and total (3-79 keV) bands. NLSy1 galaxies show the highest duty cycle of variability (87 per cent), followed by BL Lacs (82 per cent), Seyfert galaxies (56 per cent) and FSRQs (23 per cent). We obtained flux doubling/halving time in the hard X-ray band less than 10 min in 11 sources. The flux variations between the hard and soft bands in all the sources in our sample are consistent with zero lag.

Characterization of Three Vasopressin Receptor 2 Variants: An Apparent Polymorphism (V266A) and Two Loss-of-Function Mutations (R181C and M311V)

PubMed Central

Armstrong, Stephen P.; Seeber, Ruth M.; Ayoub, Mohammed Akli; Feldman, Brian J.; Pfleger, Kevin D. G.

2013-01-01

Arginine vasopressin (AVP) is released from the posterior pituitary and controls water homeostasis. AVP binding to vasopressin V2 receptors (V2Rs) located on kidney collecting duct epithelial cells triggers activation of Gs proteins, leading to increased cAMP levels, trafficking of aquaporin-2 water channels, and consequent increased water permeability and antidiuresis. Typically, loss-of-function V2R mutations cause nephrogenic diabetes insipidus (NDI), whereas gain-of-function mutations cause nephrogenic syndrome of inappropriate antidiuresis (NSIAD). Here we provide further characterization of two mutant V2Rs, R181C and M311V, reported to cause complete and partial NDI respectively, together with a V266A variant, in a patient diagnosed with NSIAD. Our data in HEK293FT cells revealed that for cAMP accumulation, AVP was about 500- or 30-fold less potent at the R181C and M311V mutants than at the wild-type receptor respectively (and about 4000- and 60-fold in COS7 cells respectively). However, in contrast to wild type V2R, the R181C mutant failed to increase inositol phosphate production, while with the M311V mutant, AVP exhibited only partial agonism in addition to a 37-fold potency decrease. Similar responses were detected in a BRET assay for β-arrestin recruitment, with the R181C receptor unresponsive to AVP, and partial agonism with a 23-fold decrease in potency observed with M311V in both HEK293FT and COS7 cells. Notably, the V266A V2R appeared functionally identical to the wild-type receptor in all assays tested, including cAMP and inositol phosphate accumulation, β-arrestin interaction, and in a BRET assay of receptor ubiquitination. Each receptor was expressed at comparable levels. Hence, the M311V V2R retains greater activity than the R181C mutant, consistent with the milder phenotype of NDI associated with this mutant. Notably, the R181C mutant appears to be a Gs protein-biased receptor incapable of signaling to inositol phosphate or recruiting β-arrestin. The etiology of NSIAD in the patient with V266A V2R remains unknown. PMID:23762448

Characterization of three vasopressin receptor 2 variants: an apparent polymorphism (V266A) and two loss-of-function mutations (R181C and M311V).

PubMed

Armstrong, Stephen P; Seeber, Ruth M; Ayoub, Mohammed Akli; Feldman, Brian J; Pfleger, Kevin D G

2013-01-01

Arginine vasopressin (AVP) is released from the posterior pituitary and controls water homeostasis. AVP binding to vasopressin V2 receptors (V2Rs) located on kidney collecting duct epithelial cells triggers activation of Gs proteins, leading to increased cAMP levels, trafficking of aquaporin-2 water channels, and consequent increased water permeability and antidiuresis. Typically, loss-of-function V2R mutations cause nephrogenic diabetes insipidus (NDI), whereas gain-of-function mutations cause nephrogenic syndrome of inappropriate antidiuresis (NSIAD). Here we provide further characterization of two mutant V2Rs, R181C and M311V, reported to cause complete and partial NDI respectively, together with a V266A variant, in a patient diagnosed with NSIAD. Our data in HEK293FT cells revealed that for cAMP accumulation, AVP was about 500- or 30-fold less potent at the R181C and M311V mutants than at the wild-type receptor respectively (and about 4000- and 60-fold in COS7 cells respectively). However, in contrast to wild type V2R, the R181C mutant failed to increase inositol phosphate production, while with the M311V mutant, AVP exhibited only partial agonism in addition to a 37-fold potency decrease. Similar responses were detected in a BRET assay for β-arrestin recruitment, with the R181C receptor unresponsive to AVP, and partial agonism with a 23-fold decrease in potency observed with M311V in both HEK293FT and COS7 cells. Notably, the V266A V2R appeared functionally identical to the wild-type receptor in all assays tested, including cAMP and inositol phosphate accumulation, β-arrestin interaction, and in a BRET assay of receptor ubiquitination. Each receptor was expressed at comparable levels. Hence, the M311V V2R retains greater activity than the R181C mutant, consistent with the milder phenotype of NDI associated with this mutant. Notably, the R181C mutant appears to be a Gs protein-biased receptor incapable of signaling to inositol phosphate or recruiting β-arrestin. The etiology of NSIAD in the patient with V266A V2R remains unknown.

Radiation resistance and comparative performance of ITO/InP and n/p InP homojunction solar cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Coutts, T. J.

1988-01-01

The radiation resistance of ITO/InP cells processed by dc magnetron sputtering is compared to that of standard n/p InP and GaAs homojunction cells. After 20 MeV proton irradiations, it is found that the radiation resistance of the present ITO/InP cell is comparable to that of the n/p homojunction InP cell and that both InP cell types have radiation resistances significantly greater than GaAs. The relatively lower radiation resistance, observed at higher fluence, for the InP cell with the deepest junction depth, is attributed to losses in the cells emitter region. Diode parameters obtained from I sub sc - V sub oc plots, data from surface Raman spectrosocpy, and determinations of surface conductivity type are used to investigate the configuration of the ITO/InP cells. It is concluded that these latter cells are n/p homojunctions, the n-region consisting of a disordered layer at the oxide semiconductor.

Radiation resistance and comparative performance of ITO/InP and n/p InP homojunction solar cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Coutts, T. J.

1988-01-01

The radiation resistance of ITO/InP cells processed by DC magnetron sputtering is compared to that of standard n/p InP and GaAs homojunction cells. After 20 MeV proton irradiations, it is found that the radiation resistance of the present ITO/InP cell is comparable to that of the n/p homojunction InP cell and that both InP cell types have radiation resistance significantly greater than GaAs. The relatively lower radiation resistance, observed at higher fluence, for the InP cell with the deepest junction depth, is attributed to losses in the cells emitter region. Diode parameters obtained from I sub sc - V sub oc plots, data from surface Raman spectroscopy, and determinations of surface conductivity types are used to investigate the configuration of the ITO/InP cells. It is concluded that thesee latter cells are n/p homojunctions, the n-region consisting of a disordered layer at the oxide semiconductor.

Occurrence of resveratrol in edible peanuts.

PubMed

Sanders, T H; McMichael, R W; Hendrix, K W

2000-04-01

Resveratrol has been associated with reduced cardiovascular disease and reduced cancer risk. This phytoalexin has been reported in a number of plant species, including grapes, and may be one of the compounds responsible for the health benefits of red wine. Analytical methods for measuring resveratrol in wine and peanuts were adapted to isolate, identify, and quantify resveratrol in several cultivars of peanuts. Aqueous ethanol (80% v/v) extracts from peanuts without seed coats were purified over alumina/silica gel columns and analyzed by reversed phase HPLC using a C-18 column. Peanuts from each market type, Virginia, runner, and Spanish, produced in four different locations contained from 0.03 to 0.14 microg of resveratrol/g. Seed coats from runner and Virginia types contained approximately 0.65 microg/g of seed coat, which is equivalent to <0.04 microg/seed. Quantitative analysis of 15 cultivars representing 3 peanut market types, which had been cold stored for up to 3 years, indicated a range of 0.02-1.79 microg/g of peanut compared to 0.6-8.0 microg/mL in red wines.

Quantitative analysis of taste bud cell numbers in fungiform and soft palate taste buds of mice.

PubMed

Ohtubo, Yoshitaka; Yoshii, Kiyonori

2011-01-07

Mammalian taste bud cells (TBCs) consist of several cell types equipped with different taste receptor molecules, and hence the ratio of cell types in a taste bud constitutes the taste responses of the taste bud. Here we show that the population of immunohistochemically identified cell types per taste bud is proportional to the number of total TBCs in the taste bud or the area of the taste bud in fungiform papillae, and that the proportions differ among cell types. This result is applicable to soft palate taste buds. However, the density of almost all cell types, the population of cell types divided by the area of the respective taste buds, is significantly higher in soft palates. These results suggest that the turnover of TBCs is regulated to keep the ratio of each cell type constant, and that taste responsiveness is different between fungiform and soft palate taste buds. Copyright © 2010 Elsevier B.V. All rights reserved.

Ghrelin inhibits proliferation and increases T-type Ca{sup 2+} channel expression in PC-3 human prostate carcinoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz-Lezama, Nundehui; Hernandez-Elvira, Mariana; Sandoval, Alejandro

Research highlights: {yields} Ghrelin decreases prostate carcinoma PC-3 cells proliferation. {yields} Ghrelin favors apoptosis in PC-3 cells. {yields} Ghrelin increase in intracellular free Ca{sup 2+} levels in PC-3 cells. {yields} Grelin up-regulates expression of T-type Ca{sup 2+} channels in PC-3 cells. {yields} PC-3 cells express T-channels of the Ca{sub V}3.1 and Ca{sub V}3.2 subtype. -- Abstract: Ghrelin is a multifunctional peptide hormone with roles in growth hormone release, food intake and cell proliferation. With ghrelin now recognized as important in neoplastic processes, the aim of this report is to present findings from a series of in vitro studies evaluating themore » cellular mechanisms involved in ghrelin regulation of proliferation in the PC-3 human prostate carcinoma cells. The results showed that ghrelin significantly decreased proliferation and induced apoptosis. Consistent with a role in apoptosis, an increase in intracellular free Ca{sup 2+} levels was observed in the ghrelin-treated cells, which was accompanied by up-regulated expression of T-type voltage-gated Ca{sup 2+} channels. Interestingly, T-channel antagonists were able to prevent the effects of ghrelin on cell proliferation. These results suggest that ghrelin inhibits proliferation and may promote apoptosis by regulating T-type Ca{sup 2+} channel expression.« less

Determination of cellular injury and death thresholds following exposure to high voltage 10ns electrical pulses

NASA Astrophysics Data System (ADS)

Ibey, Bennett L.; Roth, Caleb C.; Bernhard, Joshua A.; Pakhomov, Andrei G.; Wilmink, Gerald J.; Pakhomova, Olga

2011-03-01

Intense, nanosecond-duration electric pulses (nsEP) have been introduced as a novel modality to alter cellular function, with a mechanism of action qualitatively different from micro- and millisecond duration pulses used in electroporation. In this study, we determined the thresholds for plasma membrane injury (within 15 minutes) and cell death (at 24 hours) for 4 different cell types (CHO-K1, HeLa, Jurkat and U937). Plasma membrane injury was measured by flow cytometry using two fluorescent dyes, namely Annexin V-FITC, which binds to phosphatidylserine (PS) upon its externalization (subtle membrane injury), and propidium iodide (PI), which is typically impermeable to the cell, but enters when large pores are formed in the plasma membrane. In all cell types, 10-ns pulses caused phosphatidylserine (PS) externalization at low doses (<150kV/cm and 100 pulses for each cell type) and no PI uptake. Jurkat and U937 cell lines showed substantial cell death without uptake of PI (15 minutes post exposure) suggesting either delayed permeabilization due to swelling, or damage to intracellular components. In CHO-K1 and HeLa cell lines, PI uptake occurred at low doses relative to that necessary to cause cell death suggesting a necrotic death similar to longer pulse exposures. These findings suggest that nanosecond pulses may be beneficial in applications that require selective elimination of specific cell types.

MX Siting Investigation. Geotechnical Evaluation. Volume V. Nevada - Utah Verification Studies, FY 79. Geotechnical Data White River North CDP, Nevada.

DTIC Science & Technology

1979-08-24

5 . TYPE OF REPORT 0 PERIOD COVERED L’-, P.eRORMCG- 0 i. PERFORMING ORG. REPORT t...34 0 / AJ " " 20. ABSTRACT (Continue on reverse side It necesry and identify by block umberj hI-)? , --c. r ’ & 5 iI"’ Ia’A L_ q- ..>- 4c r, 5 - -41 ac...8217 241 291 Ill Ill 11 11 11 Ill It, T:-1: 11 1: ;, s2 2 L I I 1 5 I.L cc. a. is I.. :I 3 ’ S 0 5 2 2 1 󈧩 2 2 1 *1 -I %V44 3 IA &it 045 00 19 055

Comparison of Akt/mTOR/4E-BP1 pathway signal activation and mutations of PIK3CA in Merkel cell polyomavirus-positive and Merkel cell polyomavirus-negative carcinomas.

PubMed

Iwasaki, Takeshi; Matsushita, Michiko; Nonaka, Daisuke; Kuwamoto, Satoshi; Kato, Masako; Murakami, Ichiro; Nagata, Keiko; Nakajima, Hideki; Sano, Shigetoshi; Hayashi, Kazuhiko

2015-02-01

Merkel cell polyomavirus (MCPyV) integrates monoclonally into the genomes of approximately 80% of Merkel cell carcinomas (MCCs), affecting their clinicopathological features. The molecular mechanisms underlying MCC development after MCPyV infection remain unclear. We investigated the association of MCPyV infection with activation of the Akt/mammalian target of rapamycin (mTOR)/4E-binding protein 1 (4E-BP1) signaling pathway in MCCs to elucidate the role of these signal transductions and to identify molecular targets for treatment. We analyzed the molecular and pathological characteristics of 41 MCPyV-positive and 27 MCPyV-negative MCCs. Expression of mTOR, TSC1, and TSC2 messenger RNA was significantly higher in MCPyV-negative MCCs, and Akt (T308) phosphorylation also was significantly higher (92% vs 66%; P = .019), whereas 4E-BP1 (S65 and T70) phosphorylation was common in both MCC types (92%-100%). The expression rates of most other tested signals were high (60%-100%) and not significantly correlated with MCPyV large T antigen expression. PIK3CA mutations were observed more frequently in MCPyV-positive MCCs (6/36 [17%] vs 2/20 [10%]). These results suggest that protein expression (activation) of most Akt/mTOR/4E-BP1 pathway signals was not significantly different in MCPyV-positive and MCPyV-negative MCCs, although these 2 types may differ in tumorigenesis, and MCPyV-negative MCCs showed significantly more frequent p-Akt (T308) activation. Therefore, certain Akt/mTOR/4E-BP1 pathway signals could be novel therapeutic targets for MCC regardless of MCPyV infection status. Copyright © 2015 Elsevier Inc. All rights reserved.

New endoperoxides highly active in vivo and in vitro against artemisinin-resistant Plasmodium falciparum.

PubMed

Lobo, Lis; Cabral, Lília I L; Sena, Maria Inês; Guerreiro, Bruno; Rodrigues, António Sebastião; de Andrade-Neto, Valter Ferreira; Cristiano, Maria L S; Nogueira, Fatima

2018-04-03

The emergence and spread of Plasmodium falciparum resistance to artemisinin-based combination therapy in Southeast Asia prompted the need to develop new endoperoxide-type drugs. A chemically diverse library of endoperoxides was designed and synthesized. The compounds were screened for in vitro and in vivo anti-malarial activity using, respectively, the SYBR Green I assay and a mouse model. Ring survival and mature stage survival assays were performed against artemisinin-resistant and artemisinin-sensitive P. falciparum strains. Cytotoxicity was evaluated against mammalian cell lines V79 and HepG2, using the MTT assay. The synthesis and anti-malarial activity of 21 new endoperoxide-derived compounds is reported, where the peroxide pharmacophore is part of a trioxolane (ozonide) or a tetraoxane moiety, flanked by adamantane and a substituted cyclohexyl ring. Eight compounds exhibited sub-micromolar anti-malarial activity (IC 50 0.3-71.1 nM), no cross-resistance with artemisinin or quinolone derivatives and negligible cytotoxicity towards mammalian cells. From these, six produced ring stage survival < 1% against the resistant strain IPC5202 and three of them totally suppressed Plasmodium berghei parasitaemia in mice after oral administration. The investigated, trioxolane-tetrazole conjugates LC131 and LC136 emerged as potential anti-malarial candidates; they show negligible toxicity towards mammalian cells, ability to kill intra-erythrocytic asexual stages of artemisinin-resistant P. falciparum and capacity to totally suppress P. berghei parasitaemia in mice.

Poorly Differentiated Squamous Cell Carcinoma Arising in Tattooed Skin

PubMed Central

Sarma, Deba P.; Dentlinger, Renee B.; Forystek, Amanda M.; Stevens, Todd; Huerter, Christopher

2010-01-01

Introduction. Tattoos have increasingly become accepted by mainstream Western society. As a result, the incidence of tattoo-associated dermatoses is on the rise. The presence of a poorly differentiated squamous cell carcinoma in an old tattooed skin is of interest as it has not been previously documented. Case Presentation. A 79-year-old white homeless man of European descent presented to the dermatology clinic with a painless raised nodule on his left forearm arising in a tattooed area. A biopsy of the lesion revealed a poorly differentiated squamous cell carcinoma infiltrating into a tattoo. The lesion was completely excised and the patient remains disease-free one year later. Conclusion. All previous reports of squamous cell carcinomas arising in tattoos have been well-differentiated low-grade type or keratoacanthoma-type and are considered to be coincidental rather than related to any carcinogenic effect of the tattoo pigments. Tattoo-associated poorly differentiated invasive carcinoma appears to be extremely rare. PMID:21274289

Two-step processing for activation of the cytolysin/hemolysin of Vibrio cholerae O1 biotype El Tor: nucleotide sequence of the structural gene (hlyA) and characterization of the processed products.

PubMed

Yamamoto, K; Ichinose, Y; Shinagawa, H; Makino, K; Nakata, A; Iwanaga, M; Honda, T; Miwatani, T

1990-12-01

Vibrio cholerae O1 biotype El Tor produces and secretes a 65-kDa cytolysin/hemolysin into the culture medium. We cloned the structural gene (hlyA) for the cytolysin from the total DNA of a V. cholerae O1 El Tor strain, N86. Nucleotide sequence analysis of hlyA revealed an open reading frame consisting of 2,223 bp which can code for a protein of 741 amino acids with a molecular weight of 81,961. Consistent with this, a 79-kDa protein was identified as the product of hlyA by maxicell analysis in Escherichia coli. N-terminal amino acids of this 79-kDa HlyA protein and those of a 65-kDa El Tor cytolysin purified from V. cholerae were Asn-26 and Asn-158, respectively. The 82- and 79-kDa precursors of the 65-kDa mature cytolysin were found in V. cholerae by pulse-chase labeling and Western blot (immunoblot) analysis of hlyA products. Hemolytic activity of the 79-kDa HlyA protein from E. coli was less than 5% that for the 65-kDa cytolysin from V. cholerae. Our results suggest that in V. cholerae, the 82-kDa preprotoxin synthesized in the cytoplasm is secreted through the membranes into the culture medium as the 79-kDa inactive protoxin after cleavage of the signal peptide and is then further processed into the 65-kDa active cytolysin by release of the N-terminal 15-kDa fragment.

Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malapit, Giovanni M.; Department of Physical Sciences, University of the Philippines Baguio, Baguio City 2600; Mahinay, Christian Lorenz S.

2012-02-15

A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into themore » data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.« less

X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield.

PubMed

Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C; Goldys, Ewa M

2016-01-28

Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 10(8) and (2.0 ± 0.1) × 10(9) singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 10(7)-2 × 10(9) singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality.

Genetic Modifiers of Neurofibromatosis Type 1-Associated Café-au-Lait Macule Count Identified Using Multi-platform Analysis

PubMed Central

Pemov, Alexander; Sung, Heejong; Hyland, Paula L.; Sloan, Jennifer L.; Ruppert, Sarah L.; Baldwin, Andrea M.; Boland, Joseph F.; Bass, Sara E.; Lee, Hyo Jung; Jones, Kristine M.; Zhang, Xijun; Mullikin, James C.; Widemann, Brigitte C.; Wilson, Alexander F.; Stewart, Douglas R.

2014-01-01

Neurofibromatosis type 1 (NF1) is an autosomal dominant, monogenic disorder of dysregulated neurocutaneous tissue growth. Pleiotropy, variable expressivity and few NF1 genotype-phenotype correlates limit clinical prognostication in NF1. Phenotype complexity in NF1 is hypothesized to derive in part from genetic modifiers unlinked to the NF1 locus. In this study, we hypothesized that normal variation in germline gene expression confers risk for certain phenotypes in NF1. In a set of 79 individuals with NF1, we examined the association between gene expression in lymphoblastoid cell lines with NF1-associated phenotypes and sequenced select genes with significant phenotype/expression correlations. In a discovery cohort of 89 self-reported European-Americans with NF1 we examined the association between germline sequence variants of these genes with café-au-lait macule (CALM) count, a tractable, tumor-like phenotype in NF1. Two correlated, common SNPs (rs4660761 and rs7161) between DPH2 and ATP6V0B were significantly associated with the CALM count. Analysis with tiled regression also identified SNP rs4660761 as significantly associated with CALM count. SNP rs1800934 and 12 rare variants in the mismatch repair gene MSH6 were also associated with CALM count. Both SNPs rs7161 and rs4660761 (DPH2 and ATP6V0B) were highly significant in a mega-analysis in a combined cohort of 180 self-reported European-Americans; SNP rs1800934 (MSH6) was near-significant in a meta-analysis assuming dominant effect of the minor allele. SNP rs4660761 is predicted to regulate ATP6V0B, a gene associated with melanosome biology. Individuals with homozygous mutations in MSH6 can develop an NF1-like phenotype, including multiple CALMs. Through a multi-platform approach, we identified variants that influence NF1 CALM count. PMID:25329635

Zebrafish CaV2.1 Calcium Channels Are Tailored for Fast Synchronous Neuromuscular Transmission

PubMed Central

Naranjo, David; Wen, Hua; Brehm, Paul

2015-01-01

The CaV2.2 (N-type) and CaV2.1 (P/Q-type) voltage-dependent calcium channels are prevalent throughout the nervous system where they mediate synaptic transmission, but the basis for the selective presence at individual synapses still remains an open question. The CaV2.1 channels have been proposed to respond more effectively to brief action potentials (APs), an idea supported by computational modeling. However, the side-by-side comparison of CaV2.1 and CaV2.2 kinetics in intact neurons failed to reveal differences. As an alternative means for direct functional comparison we expressed zebrafish CaV2.1 and CaV2.2 α-subunits, along with their accessory subunits, in HEK293 cells. HEK cells lack calcium currents, thereby circumventing the need for pharmacological inhibition of mixed calcium channel isoforms present in neurons. HEK cells also have a simplified morphology compared to neurons, which improves voltage control. Our measurements revealed faster kinetics and shallower voltage-dependence of activation and deactivation for CaV2.1. Additionally, recordings of calcium current in response to a command waveform based on the motorneuron AP show, directly, more effective activation of CaV2.1. Analysis of calcium currents associated with the AP waveform indicate an approximately fourfold greater open probability (PO) for CaV2.1. The efficient activation of CaV2.1 channels during APs may contribute to the highly reliable transmission at zebrafish neuromuscular junctions. PMID:25650925

Biological characterization of HIV type 1 envelope V3 regions from mothers and infants associated with perinatal transmission.

PubMed

Matala, E; Hahn, T; Yedavalli, V R; Ahmad, N

2001-12-10

Our previous study has shown that the human immunodeficiency virus type 1 (HIV-1) envelope V3 region minor genotypes of infected mothers were transmitted to their infants and predominated initially as a homogeneous virus population in the infants (Ahmad N, Baroudy BM, Baker RC, et al.: J Virol 1995;69:1001-1012). Here we have characterized the biological properties, including cellular tropism, replication efficiency, cytopathic effects, and coreceptor utilization, of these V3 region isolates from mothers and infants. Nineteen V3 region sequences from three mother-infant pairs, including the minor variants of mothers and the major variants of infants as characterized in our previous study, were reciprocally inserted into an HIV-1 infectious molecular clone, pNL4-3, and chimeric viruses were generated by DNA transfections into HeLa cells. Equal amounts of chimeric viruses were then used to infect T lymphocyte cell lines (A3.01 and MT-2), primary blood lymphocytes (PBLs), primary monocyte-derived macrophages (MDMs), and coreceptor cell lines. We found that the V3 region chimeras failed to replicate in T lymphocyte cell lines but replicated in MDMs and PBLs, albeit at reduced levels compared with R5 laboratory HIV-1 strains. In addition, the V3 region chimeras were able to infect the HOS-CD4(+)CCR5(+) cell line, suggesting CCR5 coreceptor utilization. Moreover, the V3 region chimeras were unable to induce syncytia in MT-2 cells, indicative of non-syncytium-inducing (NSI) phenotypes. In conclusion, the HIV-1 minor genotypes of infected mothers with macrophage-tropic and NSI or R5 phenotypes are transmitted to their infants and are initially maintained with the same properties.

TREM-1 expression in craniopharyngioma and Rathke's cleft cyst: its possible implication for controversial pathology.

PubMed

Liu, Yi; Wang, Chao-Hu; Li, Dan-Ling; Zhang, Shi-Chao; Peng, Yu-Ping; Peng, Jun-Xiang; Song, Ye; Qi, Song-Tao; Pan, Jun

2016-08-02

Whether a mixed type of craniopharyngioma (CP) exists and whether papillary craniopharyngioma (pCP) is on a histopathological continuum with Rathke's cleft cyst (RCC) remain controversial. Herein, we examined the expression and localization of β-catenin, BRAF p.V600E (V600E), and triggering receptor expressed on myeloid cells-1 (TREM-1) in 58 samples including 20 pCPs, 26 adamantinomatous craniopharyngiomas (aCP), and 12 RCCs. Five aCPs were diagnosed with mixed type CPs and the remaining 21 cases were pure aCPs. Four of the 12 RCCs presented with significant squamous epithelium (SE). V600E immunoreactivity was observed in all pCPs in the cytoplasm, but not in the nuclei. aCPs and RCCs, including mixed type CP, did not express V600E. Nuclear β-catenin translocation was detected exclusively in aCPs. TREM-1 was expressed in pCPs. Additionally, TREM-1 expression was detected in the SE of 5 "mixed type" CPs, while it was absent in pure aCPs. TREM-1 was expressed in 4 RCCs with SE, but not in the remaining 8 RCCs. TREM-1 mRNA levels were compared in cultured pCP and aCP cells. TREM-1 mRNA level was significantly (p < 0.001; up to 4.045 fold) higher in pCPs than in aCPs. Western blotting revealed a significantly (p < 0.001; up to 7.19 fold) lower level of TREM-1 expression in aCP cells compared to that in pCP cells. Our findings further supported that RCC and pCP may represent two ends of a morphological spectrum. A variant showing overlapping histological features of aCP and pCP should not be considered as a mixed type.

Characterization of a new adenovirus isolated from black-tailed deer in California.

PubMed

Lehmkuhl, H D; Hobbs, L A; Woods, L W

2001-01-01

An adenovirus associated with systemic and localized vascular damage was demonstrated by transmission electron microscopy and immunohistochemistry in a newly recognized epizootic hemorrhagic disease in California black-tailed deer. In this study, we describe the cultural, physicochemical and serological characteristics of a virus isolated from lung using neonatal white-tail deer lung and turbinate cell cultures. The virus had the cultural, morphological and physicochemical characteristics of members of the Adenoviridae family. The virus would not replicate in low passage fetal bovine, caprine or ovine cells. Antiserum to the deer adenovirus, strain D94-2569, neutralized bovine adenovirus type-6 (BAdV-6), BAdV-7, and caprine adenovirus type-1 (GAdV-1). Antiserum to BAdV-6 did not neutralize the deer adenovirus but antiserum to BAdV-7 and GAdV-1 neutralized the deer adenovirus. Cross-neutralization with the other bovine, caprine and ovine adenovirus species was not observed. Restriction endonuclease patterns generated for the deer adenovirus were unique compared to those for the currently recognized bovine, caprine and ovine adenovirus types. Amino acid sequence alignments of the hexon gene from the deer adenovirus strain D94-2569 indicate that it is a member of the proposed new genus (Atadenovirus) of the Adenoviridae family. While closely related antigenically to BAdV-7 and GAdV-1, the deer adenovirus appears sufficiently distinct culturally and molecularly to justify consideration as a new adenovirus type.

Electronic Band Structure Tuning of Highly-Mismatched-Alloys for Energy Conversion Applications

NASA Astrophysics Data System (ADS)

Ting, Min

Highly-mismatched alloys: ZnO1-xTe x and GaN1-xSb x are discussed within the context of finding the suitable material for a cost-effective Si-based tandem solar cell (SBTSC). SBTSC is an attractive concept for breaking through the energy conversion efficiency theoretical limit of a single junction solar cell. Combining with a material of 1.8 eV band gap, SBTSC can theoretically achieve energy conversion efficiency > 45%. ZnO and GaN are wide band gap semiconductors. Alloying Te in ZnO and alloying Sb in GaN result in large band gap reduction to < 2 eV from 3.3 eV and 3.4 eV respectively. The band gap reduction is majorly achieved by the upward shift of valence band (VB). Incorporating Te in ZnO modifies the VB of ZnO through the valence-band anticrossing (VBAC) interaction between localized Te states and ZnO VB delocalized states, which forms a Te-derived VB at 1 eV above the host VB. Similar band structure modification is resulted from alloying Sb in GaN. Zn1-xTex and GaN 1-xSbx thin films are synthesized across the whole composition range by pulsed laser deposition (PLD) and low temperature molecular beam epitaxy (LT-MBE) respectively. The electronic band edges of these alloys are measured by synchrotron X-ray absorption, emission, and the X-ray photoelectron spectroscopies. Modeling the optical absorption coefficient with the band anticrossing (BAC) model revealed that the Te and Sb defect levels to be at 0.99 eV and 1.2 eV above the VB of ZnO and GaN respectively. Electrically, Zn1-xTex is readily n-type conductive and GaN1-xSbx is strongly p-type conductive. A heterojunction device of p-type GaN 0.93Sb0.07 with n-type ZnO0.77Te0.93 upper cell (band gap at 1.8 eV) on Si bottom cell is proposed as a promising SBTSC device.

Progress in the Development of Metamorphic Multi-Junction III-V Space-Solar Cells at Essential Research Incorporated

NASA Technical Reports Server (NTRS)

Sinharoy, Samar; Patton, Martin O.; Valko, Thomas M., Sr.; Weizer, Victor G.

2002-01-01

Theoretical calculations have shown that highest efficiency III-V multi-junction solar cells require alloy structures that cannot be grown on a lattice-matched substrate. Ever since the first demonstration of high efficiency metamorphic single junction 1.1 eV and 1.2 eV InGaAs solar cells by Essential Research Incorporated (ERI), interest has grown in the development of multi-junction cells of this type using graded buffer layer technology. ERI is currently developing a dual-junction 1.6 eV InGaP/1.1 eV InGaAs tandem cell (projected practical air-mass zero (AM0), one-sun efficiency of 28%, and 100-sun efficiency of 37.5%) under a Ballistic Missile Defense Command (BMDO) SBIR Phase II program. A second ongoing research effort at ERI involves the development of a 2.1 eV AlGaInP/1.6 eV InGaAsP/1.2 eV InGaAs triple-junction concentrator tandem cell (projected practical AM0 efficiency of 36.5% under 100 suns) under a SBIR Phase II program funded by the Air Force. We are in the process of optimizing the dual-junction cell performance. In case of the triple-junction cell, we have developed the bottom and the middle cell, and are in the process of developing the layer structures needed for the top cell. A progress report is presented in this paper.

Suzaku spectra of a Type-II supernova remnant, Kes 79

NASA Astrophysics Data System (ADS)

Sato, Tamotsu; Koyama, Katsuji; Lee, Shiu-Hang; Takahashi, Tadayuki

2016-06-01

This paper reports on results of a Suzaku observation of the supernova remnant (SNR) Kes 79 (G33.6+0.1). The X-ray spectrum is best fitted by a two-temperature model: a non-equilibrium ionization (NEI) plasma and a collisional ionization equilibrium (CIE) plasma. The NEI plasma is spatially confined within the inner radio shell with kT ˜ 0.8 keV, while the CIE plasma is found in more spatially extended regions associated with the outer radio shell with kT ˜0.2 keV and solar abundance. Therefore, the NEI plasma is attributable to the SN ejecta, and the CIE plasma is the forward shocked interstellar medium. In the NEI plasma, we discovered K-shell lines of Al, Ar, and Ca for the first time. The abundance pattern and estimated mass of the ejecta are consistent with a core-collapse supernova explosion of a ˜30-40M⊙ progenitor star. An Fe line with a center energy of ˜6.4 keV is also found in the southeast (SE) portion of the SNR, a close peripheral region around dense molecular clouds. One possibility is that the line is associated with the ejecta. However, the centroid energy of ˜6.4 keV and the spatial distribution of enhancement near the SE peripheral do not favor this scenario. Since the ˜6.4 keV emitting region coincides with the molecular clouds, we propose another possibility, that the Fe line is due to K-shell ionization of neutral Fe by the interaction of locally accelerated protons (LECRp) with the surrounding molecular cloud. Both of these possibilities, heated ejecta or LECRp origin, are discussed based on the observational facts.

Non-precious metal catalysts prepared from precursors comprising cyanamide and polyaniline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Hoon Taek; Zelenay, Piotr

A catalyst for oxygen reduction reaction (ORR) for a fuel cell was prepared by pyrolyzing a mixture of polyaniline, cyanamide, carbon black, and a non-precious metal salt under an inert atmosphere. The pyrolyzed product was treated to remove acid soluble components and then pyrolyzed again. The resulting powder was used to prepare a cathode for a membrane electrode assembly that was used in a fuel cell. When iron(III) chloride was used as the salt, the resulting catalyst was porous with a web-shaped structure. It displayed a maximum power density of 0.79 W/cm at 0.4 V in H.sub.2/O.sub.2 at 1.0 barmore » back pressure.« less

EPR and transient capacitance studies on electron-irradiated silicon solar cells

NASA Technical Reports Server (NTRS)

Lee, Y. H.; Cheng, L. J.; Mooney, P. M.; Corbett, J. W.

1977-01-01

One and two ohm-cm solar cells irradiated with 1 MeV electrons at 30 C were studied using both EPR and transient capacitance techniques. In 2 ohm-cm cells, Si-G6 and Si-G15 EPR spectra and majority carrier trapping levels at (E sub V + 0.23) eV and (E sub V + 0.38) eV were observed, each of which corresponded to the divacancy and the carbon-oxygen-vacancy complex, respectively. In addition, a boron-associated defect with a minority carrier trapping level at (E sub C -0.27) eV was observed. In 1 ohm-cm cells, the G15 spectrum and majority carrier trap at (E sub V + 0.38) eV were absent and an isotropic EPR line appeared at g = 1.9988 (+ or - 0.0003); additionally, a majority carrier trapping center at (E sub V + 0.32) eV, was found which could be associated with impurity lithium. The formation mechanisms of these defects are discussed according to isochronal annealing data in electron-irradiated p-type silicon.

Selective silencing of full-length CD80 but not IgV-CD80 leads to impaired clonal deletion of self-reactive T cells and altered regulation of immune responses.

PubMed

Bugeon, L; Hargreaves, R E; Crompton, T; Outram, S; Rahemtulla, A; Porter, A C; Dallman, M J

2001-01-01

Co-stimulation provided by the B7 family of proteins underpins the development of protective immunity. There are three identified members of this family: CD80, its splice variant IgV-CD80 and CD86. It has hitherto been difficult to analyze the expression and function of IgV-CD80 since there are no appropriate reagents capable of distinguishing it from CD80. We have generated mice, by gene targeting, the lack CD80 whilst maintaining expression of IgV-CD80. Mutant animals did not delete T cells bearing mammary tumor virus-reactive TCR as efficiently as wild-type animals. We also demonstrate the importance of IgV-CD80 in the responses of recently activated cells and reveal a role for CD80 in sustaining T cell responses. CD86, whilst critical to primary T cell activation, made only a minor contribution to re-activation of normal cells.

Induction and quantification of gammma-H2AX foci following cx- and gamma-irradiaton

NASA Technical Reports Server (NTRS)

Leatherbarrow, E. L.; Cucinotta, F. A.; O'Neill, Peter

2004-01-01

Following DNA damage the histone H2AX becomes phosphorylated and can be visualised by immunofluorescence as an indicator of DSBs in individual cells. Using a wild type hamster cell line (V79-4) exposed to either a-particles or to Co-60 gamma-rays to induce DNA DSBs at different doses (20-200OmGy), the dose dependent induction of gamma-H2AX foci were scored both manually (by eye) and using image analysis. A linearly dependence on dose was found for both radiations. The number of DSBs determined by image analysis after a post-irradiation period of 30 minutes at 37 C, is 16.6 foci/cell/Gy for alpha-irradiation and 12.2 foci/cell/Gy for gamma-irradiation; the latter being 3-4 times the levels observed by eye and comparable to gamma-radiation-induced levels of prompt DSBs more recently reported using pulse field gel electrophoresis (approx. 16 DSBs/Gy). The average size of the gamma-H2AX foci induced by alpha-irradiation (0.30 square micrometers) is approximately 1.5 times larger than those induced by gamma-irradiation (0.19 square micrometers). The timescale of induction and removal of DSBs up to 24 hours post-irradiation, was investigated with gamma-H2AX foci levels found to remain significantly higher than controls for 4 or 6 hours in gamma-irradiated samples or alpha irradiated samples, respectively. These results demonstrate that not only gamma radiation but also alpha-radiation induce phosphorylation of the H2AX histone in response to DSBs even at low doses (20mGy for gamma-rays, 1 track/cell on average for alpha-particles) and the variation in size and dephosphorylation of the induced foci is dependent on radiation quality (LET).

Roseomonas arctica sp. nov., isolated from arctic glacial foreland soil.

PubMed

Qiu, Xia; Qu, Zhihao; Jiang, Fan; Lin, Yingjun; Zhang, Yumin; Chang, Xulu; Da, Xuyang; Deng, Sangsang; Kim, Myongchol; Fang, Chengxiang; Peng, Fang

2016-03-01

A novel psychrotolerant bacterium, designed strain M6-79 T , was isolated from an arctic glacial foreland soil sample collected from Ny-Ålesund in the Svalbard Archipelago, Norway. Cells of strain M6-79 T were Gram-stain-negative, rod-shaped and produced a red-pigment. Strain M6-79 T was strictly aerobic, non-motile, non-endospore-forming, oxidase-negative and catalase-positive. Based on 16S rRNA gene sequence analysis, strain M6-79 T was phylogenetically related to Roseomonas aquatica TR53 T (95.2 % 16S rRNA gene sequence similarity), Roseomonas lacus TH-G33 T (94.3 %), ' Roseomonas sediminicola' FW-3 (94.3 %), Roseomonas terrae DS-48 T (94.1 %) and Roseomonas soli 5N26 T (94.1 %). The unique isoprenoid quinone detected in strain M6-79 T was Q-9. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unknown aminolipid and one unknown lipid. Strain M6-79 T possessed C 18 : 1 ω7 c , C 16 : 0 and summed feature 3 (C 16 : 1 ω6 c and/or C 16 : 1 ω7 c ) as the predominant fatty acids, and the DNA G+C content was 71.2 mol%. Combined data from phylogenetic, phenotypic and chemotaxonomic studies revealed that strain M6-79 T represents a novel species of the genus Roseomonas , for which the name Roseomonas arctica sp. nov. is proposed. The type strain is strain M6-79 T ( = CCTCC AB 2013101 T  = LMG 28251 T ).

Rho GTPase activity modulates paramyxovirus fusion protein-mediated cell-cell fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schowalter, Rachel M.; Wurth, Mark A.; Aguilar, Hector C.

2006-07-05

The paramyxovirus fusion protein (F) promotes fusion of the viral envelope with the plasma membrane of target cells as well as cell-cell fusion. The plasma membrane is closely associated with the actin cytoskeleton, but the role of actin dynamics in paramyxovirus F-mediated membrane fusion is unclear. We examined cell-cell fusion promoted by two different paramyxovirus F proteins in three cell types in the presence of constitutively active Rho family GTPases, major cellular coordinators of actin dynamics. Reporter gene and syncytia assays demonstrated that expression of either Rac1{sup V12} or Cdc42{sup V12} could increase cell-cell fusion promoted by the Hendra ormore » SV5 glycoproteins, though the effect was dependent on the cell type expressing the viral glycoproteins. In contrast, RhoA{sup L63} decreased cell-cell fusion promoted by Hendra glycoproteins but had little affect on SV5 F-mediated fusion. Also, data suggested that GTPase activation in the viral glycoprotein-containing cell was primarily responsible for changes in fusion. Additionally, we found that activated Cdc42 promoted nuclear rearrangement in syncytia.« less

A study of lip print pattern in Goan dental students - A digital approach.

PubMed

Prabhu, Rachana V; Dinkar, Ajit; Prabhu, Vishnudas

2012-10-01

To find the incidence of different types of lip patterns, the dominant pattern, quadrant wise, amongst the Goan population. To assess, the quadrant wise differences in lip patterns among males and females and to report new lip print pattern in Goan population. Lip prints of 100 students studying in Goa Dental College & Hospital were taken using 14 mm wide and 50 mm long Scotch tape without any distortion. These prints were then scanned (256 gray shades at a resolution of 300 dpi.) for the digital analysis. Using various applications of Adobe Photoshop 7 software an attempt was made to trace each and every line. K. Suzuki and Y. Tsuchihashi's classification was followed to define the patterns of the grooves. The current study has found the most predominant pattern in Quadrant I to be Type V (580 lines; 52.39%) followed in order by Type I' (196 lines; 17.70%), Type I (166 lines; 14.99%), Type II (166 lines; 10.47%), Type IV (40 lines; 3.61%), Type III (9 lines; 0.81%). In Quadrant II of this study the most predominant pattern recorded was Type V (589 lines; 50.47%) followed in order by Type I' (209 lines; 17.90%), Type I (204 lines; 17.48%), Type II (130 lines; 11.13%), Type IV (34 lines; 2.91%), Type III (1 line; 0.08%). In Quadrant III of this study the most predominant pattern recorded was again Type V (484 lines; 52.09%) followed in order by Type I' (174 lines; 18.72%), Type I (155 lines; 16.68%), Type II (102 lines; 10.97%), Type IV (9 lines; 0.96%), Type III (5 lines; 0.53%). In Quadrant IV of this study the most predominant pattern recorded was Type V (543 lines; 58.19%) followed in order by Type I (151 lines; 16.18%), Type I' (138 lines; 14.79%), Type II (85 lines; 9.11%), Type III (9 lines; 0.96%), Type IV (7 line; 0.75%). In all four Quadrants the most predominant pattern found in males and females was Type V. The present study recorded the following types of type V patterns for the first time; Trifurcations, Bridge or 'H' pattern, Horizontal Lines, Cartwheel, Pineapple Skin and Multiple Branching Appearance. The digital method of analyzing the Lip Print images using Adobe Photoshop 7 software serves as a convenient method that provides better visualization and ease in identification and recording of the Lip Print pattern. Predominant pattern in all four quadrants was Type V followed by the linear pattern i.e. Type I' in quadrants I, II, and III and Type I in quadrant IV in the studied population. Distribution of pattern is not affected by the sex. Although type V is the most predominant pattern found in Goan population, the sub-classification of this type defines the more defined term and aids in accuracy of the classification. Copyright © 2012. Published by Elsevier Ltd.

Cross-point-type spin-transfer-torque magnetoresistive random access memory cell with multi-pillar vertical body channel MOSFET

NASA Astrophysics Data System (ADS)

Sasaki, Taro; Endoh, Tetsuo

2018-04-01

In this paper, from the viewpoint of cell size and sensing margin, the impact of a novel cross-point-type one transistor and one magnetic tunnel junction (1T–1MTJ) spin-transfer-torque magnetoresistive random access memory (STT-MRAM) cell with a multi-pillar vertical body channel (BC) MOSFET is shown for high density and wide sensing margin STT-MRAM, with a 10 ns writing period and 1.2 V V DD. For that purpose, all combinations of n/p-type MOSFETs and bottom/top-pin MTJs are compared, where the diameter of MTJ (D MTJ) is scaled down from 55 to 15 nm and the tunnel magnetoresistance (TMR) ratio is increased from 100 to 200%. The results show that, benefiting from the proposed STT-MRAM cell with no back bias effect, the MTJ with a high TMR ratio (200%) can be used in the design of smaller STT-MRAM cells (over 72.6% cell size reduction), which is a difficult task for conventional planar MOSFET based design.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qu, Shiwei; Wang, Huan; Mo, Daize

A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety,more » which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.« less

Myelogenous leukemia in a bearded dragon (Acanthodraco vitticeps).

PubMed

Tocidlowski, M E; McNamara, P L; Wojcieszyn, J W

2001-03-01

A 3-yr-old bearded dragon (Acanthodraco vitticeps) presented with lethargy, a swollen right elbow joint, inability to move its rear limbs normally, and marked leukocytosis. The majority of leukocytes were an abnormal mononuclear lymphoid-type cell with a high nuclear to cytoplasmic ratio, a slightly blue cytoplasm, nuclei with coarsely granular chromatin, and some nuclear clefts. Acute leukemia of lymphoid or myeloid origin was tentatively diagnosed. The abnormal mononuclear leukocyte cell population stained positively for the myeloid cytochemical stains: peroxidase, chloroacetate esterase, and L1-calprotectin. The abnormal cell population of the peripheral blood did not stain with the lymphoid cytochemical stains: alpha-naphthyl butyrate esterase, CD3, and CD79a.

Maintenance of a bone collagen phenotype by osteoblast-like cells in 3D periodic porous titanium (Ti-6Al-4 V) structures fabricated by selective electron beam melting

PubMed Central

Hrabe, Nikolas W.; Heinl, Peter; Bordia, Rajendra K.; Körner, Carolin; Fernandes, Russell J.

2013-01-01

Regular 3D periodic porous Ti-6Al-4 V structures were fabricated by the selective electron beam melting method (EBM) over a range of relative densities (0.17–0.40) and pore sizes (500–1500 μm). Structures were seeded with human osteoblast-like cells (SAOS-2) and cultured for four weeks. Cells multiplied within these structures and extracellular matrix collagen content increased. Type I and type V collagens typically synthesized by osteoblasts were deposited in the newly formed matrix with time in culture. High magnification scanning electron microscopy revealed cells attached to surfaces on the interior of the structures with an increasingly fibrous matrix. The in-vitro results demonstrate that the novel EBM-processed porous structures, designed to address the effect of stress-shielding, are conducive to osteoblast attachment, proliferation and deposition of a collagenous matrix characteristic of bone. PMID:23869614

Type-specific and cross-reactive antibodies and T cell responses in norovirus VLP immunized mice are targeted both to conserved and variable domains of capsid VP1 protein.

PubMed

Malm, Maria; Tamminen, Kirsi; Vesikari, Timo; Blazevic, Vesna

2016-10-01

Norovirus (NoV)-specific antibodies, which block binding of the virus-like particles (VLPs) to the cell receptors are conformation dependent and directed towards the most exposed domain of the NoV capsid VP1 protein, the P2 domain. Limited data are available on the antibodies directed to other domains of the VP1, and even less on the NoV VP1-specific T cell epitopes. In here, BALB/c mice were immunized with six VLPs derived from NoV GII.4-1999, GII.4-2009 (New Orleans), GII.4-2012 (Sydney), GII.12, GI.1, and G1.3. Serum immunoglobulin G binding antibodies, histo-blood group antigen blocking antibodies and T cell responses using type-specific and heterologous NoV VLPs, P-dimers and 76 overlapping synthetic peptides, spanning the entire 539 amino acid sequence of GII.4 VP1, were determined. The results showed that at least half of the total antibody content is directed towards conserved S domain of the VP1. Only a small fraction (<1%) of the VP1 binding antibodies were blocking/neutralizing. With the use of matrix peptide pools and individual peptides, seven CD4 + and CD8 + T cell restricted epitopes were mapped, two located in S domain, four in P2 domain and one in P1 domain of NoV VP1. The epitopes were GII.4 strain-specific but also common GII.4 genotype-specific T cell epitopes were identified. More importantly, the results suggest a 9-amino acids long sequence ( 318 PAPLGTPDF 326 ) in P2 domain of VP1 as a universal NoV genogroup II-specific CD8 + T cell epitope. Distribution of the T cell epitopes alongside the capsid VP1 indicates the need of the complete protein for high immunogenicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modulation of Ca(v)3.1 T-type Ca2+ channels by the ran binding protein RanBPM.

PubMed

Kim, Taehyun; Kim, Sunoh; Yun, Hyung-Mun; Chung, Kwang Chul; Han, Ye Sun; Shin, Hee-Sup; Rhim, Hyewhon

2009-01-02

In order to study the currently unknown cellular signaling pathways of Ca(v)3.1 T-type Ca(2+) channels (Ca(v)3.1 channels), we performed a yeast two-hybrid screening using intracellular domains of Ca(v)3.1 alpha1 subunit as bait. After screening the human brain cDNA library, several proteins, including RanBPM, were identified as interacting with Ca(v)3.1 channels. RanBPM was found to bind to the cytoplasmic intracellular loop between transmembrane domains I and II of Ca(v)3.1 channels. Using whole-cell patch-clamp techniques, we found that Ca(v)3.1 currents were increased by the expression of RanBPM in HEK293/Ca(v)3.1 cells. We next examined whether RanBPM affected the biophysical properties and plasma membrane expression of Ca(v)3.1 channels. Furthermore, we showed that the PKC activator inhibited Ca(v)3.1 currents, an effect that was abolished by the expression of RanBPM. These results suggest that RanBPM could be a key regulator of Ca(v)3.1 channel-mediated signaling pathways.

Reduction of low potential electron acceptors requires the CbcL inner membrane cytochrome of Geobacter sulfurreducens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zacharoff, Lori; Chan, Chi Ho; Bond, Daniel R.

2015-09-05

The respiration of metals by the bacterium Geobacter sulfurreducens requires electrons generated by metabolism to pass from the interior of the cell to electron acceptors beyond the cell membranes. The G. sulfurreducens inner membrane multiheme c-type cytochrome ImcH is required for respiration to extracellular electron acceptors with redox potentials greater than - 0.1 V vs. SHE, but ImcH is not essential for electron transfer to lower potential acceptors. In contrast, deletion of cbcL, encoding an inner membrane protein consisting of b-type and multiheme c-type cytochrome domains, severely affected reduction of low potential electron acceptors such as Fe(III)-oxides and electrodes poisedmore » at - 0.1 V vs. SHE. Catalytic cyclic voltammetry of a ΔcbcL strain growing on poised electrodes revealed a 50 mV positive shift in driving force required for electron transfer out of the cell. In non-catalytic conditions, low-potential peaks present in wild type biofilms were absent in ΔcbcL mutants. Expression of cbcL in trans increased growth at low redox potential and restored features to cyclic voltammetry. This evidence supports a model where CbcL is a component of a second electron transfer pathway out of the G. sulfurreducens inner membrane that dominates when redox potential is at or below - 0.1 V vs. SHE.« less

Serotonin regulates voltage-dependent currents in type Ie(A) and Ii interneurons of Hermissenda

PubMed Central

Jin, Nan Ge

2011-01-01

Serotonin (5-HT) has both direct and modulatory actions on central neurons contributing to behavioral arousal and cellular-synaptic plasticity in diverse species. In Hermissenda, 5-HT produces changes in intrinsic excitability of different types of identified interneurons in the circumesophageal nervous system. Using whole cell patch-clamp techniques we have examined membrane conductance changes produced by 5-HT that contribute to intrinsic excitability in two identified classes of interneurons, types Ii and IeA. Whole cell currents were examined before and after 5-HT application to the isolated nervous system. A 4-aminopyridine-sensitive transient outward K+ current [IK(A)], a tetraethylammonium-sensitive delayed rectifier K+ current [IK(V)], an inward rectifier K+ current [IK(IR)], and a hyperpolarization-activated current (Ih) were characterized. 5-HT decreased the amplitude of IK(A) and IK(V) in both type Ii and IeA interneurons. However, differences in 5-HT's effects on the activation-inactivation kinetics were observed in different types of interneurons. 5-HT produced a depolarizing shift in the activation curve of IK(V) and a hyperpolarizing shift in the inactivation curve of IK(A) in type Ii interneurons. In contrast, 5-HT produced a depolarizing shift in the activation curve and a hyperpolarizing shift in the inactivation curve of both IK(V) and IK(A) in type IeA interneurons. In addition, 5-HT decreased the amplitude of IK(IR) in type Ii interneurons and increased the amplitude of Ih in type IeA interneurons. These results indicate that 5-HT-dependent changes in IK(A), IK(V), IK(IR), and Ih contribute to multiple mechanisms that synergistically support modulation of increased intrinsic excitability associated with different functional classes of identified type I interneurons. PMID:21813747

Cabozantinib Versus Sunitinib As Initial Targeted Therapy for Patients With Metastatic Renal Cell Carcinoma of Poor or Intermediate Risk: The Alliance A031203 CABOSUN Trial

PubMed Central

Halabi, Susan; Sanford, Ben L.; Hahn, Olwen; Michaelson, M. Dror; Walsh, Meghara K.; Feldman, Darren R.; Olencki, Thomas; Picus, Joel; Small, Eric J.; Dakhil, Shaker; George, Daniel J.; Morris, Michael J.

2017-01-01

Purpose Cabozantinib is an oral potent inhibitor of vascular endothelial growth factor receptor 2, MET, and AXL and is a standard second-line therapy for metastatic renal cell carcinoma (mRCC). This randomized phase II multicenter trial evaluated cabozantinib compared with sunitinib as first-line therapy in patients with mRCC. Patients and Methods Eligible patients had untreated clear cell mRCC and Eastern Cooperative Oncology Group performance status of 0 to 2 and were intermediate or poor risk per International Metastatic Renal Cell Carcinoma Database Consortium criteria. Patients were randomly assigned at a one-to-one ratio to cabozantinib (60 mg once per day) or sunitinib (50 mg once per day; 4 weeks on, 2 weeks off). Progression-free survival (PFS) was the primary end point. Objective response rate (ORR), overall survival, and safety were secondary end points. Results From July 2013 to April 2015, 157 patients were randomly assigned (cabozantinib, n = 79; sunitinib, n = 78). Compared with sunitinib, cabozantinib treatment significantly increased median PFS (8.2 v 5.6 months) and was associated with a 34% reduction in rate of progression or death (adjusted hazard ratio, 0.66; 95% CI, 0.46 to 0.95; one-sided P = .012). ORR was 33% (95% CI, 23% to 44%) for cabozantinib versus 12% (95% CI, 5.4% to 21%) for sunitinib. All-causality grade 3 or 4 adverse events were 67% for cabozantinib and 68% for sunitinib and included diarrhea (cabozantinib, 10% v sunitinib, 11%), fatigue (6% v 15%), hypertension (28% v 22%), palmar-plantar erythrodysesthesia (8% v 4%), and hematologic adverse events (3% v 22%). Conclusion Cabozantinib demonstrated a significant clinical benefit in PFS and ORR over standard-of-care sunitinib as first-line therapy in patients with intermediate- or poor-risk mRCC. PMID:28199818

Compensatory branching morphogenesis of stalk cells in the Drosophila trachea.

PubMed

Francis, Deanne; Ghabrial, Amin S

2015-06-01

Tubes are essential for nutrient transport and gas exchange in multicellular eukaryotes, but how connections between different tube types are maintained over time is unknown. In the Drosophila tracheal system, mutations in oak gall (okg) and conjoined (cnj) confer identical defects, including late onset blockage near the terminal cell-stalk cell junction and the ectopic extension of autocellular, seamed tubes into the terminal cell. We determined that okg and cnj encode the E and G subunits of the vacuolar ATPase (vATPase) and showed that both the V0 and V1 domains are required for terminal cell morphogenesis. Remarkably, the ectopic seamed tubes running along vATPase-deficient terminal cells belonged to the neighboring stalk cells. All vATPase-deficient tracheal cells had reduced apical domains and terminal cells displayed mislocalized apical proteins. Consistent with recent reports that the mTOR and vATPase pathways intersect, we found that mTOR pathway mutants phenocopied okg and cnj. Furthermore, terminal cells depleted for the apical determinants Par6 or aPKC had identical ectopic seamed tube defects. We thus identify a novel mechanism of compensatory branching in which stalk cells extend autocellular tubes into neighboring terminal cells with undersized apical domains. This compensatory branching also occurs in response to injury, with damaged terminal cells being rapidly invaded by their stalk cell neighbor. © 2015. Published by The Company of Biologists Ltd.

Phagocytic cells contribute to the antibody-mediated elimination of pulmonary-infected SARS coronavirus.

PubMed

Yasui, Fumihiko; Kohara, Michinori; Kitabatake, Masahiro; Nishiwaki, Tetsu; Fujii, Hideki; Tateno, Chise; Yoneda, Misako; Morita, Kouichi; Matsushima, Kouji; Koyasu, Shigeo; Kai, Chieko

2014-04-01

While the 2002-2003 outbreak of severe acute respiratory syndrome (SARS) resulted in 774 deaths, patients who were affected with mild pulmonary symptoms successfully recovered. The objective of the present work was to identify, using SARS coronavirus (SARS-CoV) mouse infection models, immune factors responsible for clearing of the virus. The elimination of pulmonary SARS-CoV infection required the activation of B cells by CD4(+) T cells. Furthermore, passive immunization (post-infection) with homologous (murine) anti-SARS-CoV antiserum showed greater elimination efficacy against SARS-CoV than that with heterologous (rabbit) antiserum, despite the use of equivalent titers of neutralizing antibodies. This distinction was mediated by mouse phagocytic cells (monocyte-derived infiltrating macrophages and partially alveolar macrophages, but not neutrophils), as demonstrated both by adoptive transfer from donors and by immunological depletion of selected cell types. These results indicate that the cooperation of anti-SARS-CoV antibodies and phagocytic cells plays an important role in the elimination of SARS-CoV. Copyright © 2014 Elsevier Inc. All rights reserved.

Classification of nanoparticle diffusion processes in vital cells by a multifeature random forests approach: application to simulated data, darkfield, and confocal laser scanning microscopy

NASA Astrophysics Data System (ADS)

Wagner, Thorsten; Kroll, Alexandra; Wiemann, Martin; Lipinski, Hans-Gerd

2016-04-01

Darkfield and confocal laser scanning microscopy both allow for a simultaneous observation of live cells and single nanoparticles. Accordingly, a characterization of nanoparticle uptake and intracellular mobility appears possible within living cells. Single particle tracking makes it possible to characterize the particle and the surrounding cell. In case of free diffusion, the mean squared displacement for each trajectory of a nanoparticle can be measured which allows computing the corresponding diffusion coefficient and, if desired, converting it into the hydrodynamic diameter using the Stokes-Einstein equation and the viscosity of the fluid. However, within the more complex system of a cell's cytoplasm unrestrained diffusion is scarce and several other types of movements may occur. Thus, confined or anomalous diffusion (e.g. diffusion in porous media), active transport, and combinations thereof were described by several authors. To distinguish between these types of particle movement we developed an appropriate classification method, and simulated three types of particle motion in a 2D plane using a Monte Carlo approach: (1) normal diffusion, using random direction and step-length, (2) subdiffusion, using confinements like a reflective boundary with defined radius or reflective objects in the closer vicinity, and (3) superdiffusion, using a directed flow added to the normal diffusion. To simulate subdiffusion we devised a new method based on tracks of different length combined with equally probable obstacle interaction. Next we estimated the fractal dimension, elongation and the ratio of long-time / short-time diffusion coefficients. These features were used to train a random forests classification algorithm. The accuracy for simulated trajectories with 180 steps was 97% (95%-CI: 0.9481-0.9884). The balanced accuracy was 94%, 99% and 98% for normal-, sub- and superdiffusion, respectively. Nanoparticle tracking analysis was used with 100 nm polystyrene particles to get trajectories for normal diffusion. As a next step we identified diffusion types of nanoparticles in vital cells and incubated V79 fibroblasts with 50 nm gold nanoparticles, which appeared as intensely bright objects due to their surface plasmon resonance. The movement of particles in both the extracellular and intracellular space was observed by dark field and confocal laser scanning microscopy. After reducing background noise from the video it became possible to identify individual particle spots by a maximum detection algorithm and trace them using the robust single-particle tracking algorithm proposed by Jaqaman, which is able to handle motion heterogeneity and particle disappearance. The particle trajectories inside cells indicated active transport (superdiffusion) as well as subdiffusion. Eventually, the random forest classification algorithm, after being trained by the above simulations, successfully classified the trajectories observed in live cells.

Compressibility and expansivity of anglesite (PbSO4) using in situ synchrotron X-ray diffraction at high-pressure and high-temperature conditions

NASA Astrophysics Data System (ADS)

Li, Bo; Xu, Jingui; Chen, Wei; Ye, Zhilin; Huang, Shijie; Fan, Dawei; Zhou, Wenge; Xie, Hongsen

2018-04-01

The compressibility and expansivity of anglesite (PbSO4) have been measured at high pressure up to 21.6 GPa and high temperature up to 700 K using in situ angle-dispersive X-ray diffraction and diamond anvil cell. The third-order Birch-Murnaghan equation of state (III-BM-EoS) was used to analyze the pressure-volume (P-V) data of PbSO4. We obtained the bulk modulus K 0 = 59(1) GPa, and its pressure derivative K0' = 5.3(4), respectively. Using Holland-Powell thermal EoS to fit the temperature-volume (T-V) data, the thermal expansion coefficient α 0 = 4.59(2) × 10- 5 K- 1 for PbSO4 was also derived. Simultaneously, the ambient-pressure axial compressibilities (β a0 = 1.79(4) × 10- 3 GPa- 1, β b0 = 1.75(5) × 10- 3 GPa- 1, β c0 = 2.12(4) × 10- 3 GPa- 1) and axial thermal expansivities (α a0 = 1.23(4) × 10- 5 K- 1, α b0 = 1.93(2) × 10- 5 K- 1, and α c0 = 1.43(1) × 10- 5 K- 1) along a-axis, b-axis and c-axis were derived at 300 K, respectively. Furthermore, the potential influencing factors (e.g., the effective size of M2+ cation, polarizability and electronegativity) on the bulk moduli of barite-type (belonging to Pbnm space group) sulfates (anglesite, barite, and celestine) were discussed. We found that the polarizability might be the most important factor. Finally, the anisotropic linear compressibility and thermal expansivity in barite-type sulfates were also discussed, respectively.

Super-Nernstian pH sensors based on WO3 nanosheets

NASA Astrophysics Data System (ADS)

Kuo, Chao-Yin; Wang, Shui-Jinn; Ko, Rong-Ming; Tseng, Hung-Hao

2018-04-01

The effects of the surface morphology of hydrothermally grown WO3 nanosheets (NSs) and sputtering WO3 film on the performance of pH sensing electrodes are presented and compared in the pH range of 2–12. Using a separated electrode of an extended-gate field-effect transistor (EGFET) configuration, the WO3 nanosheet (NS) pH sensor shows a sensitivity of 63.37 mV/pH, a good linearity of 0.9973, a low voltage hysteresis of 4.79 mV, and a low drift rate of 3.18 mV/h. In contrast, the film-type one shows a typical sensitivity of only 50.08 mV/pH and a linearity of 0.9932. The super-Nernstian response could be attributed to the significant increase in the number of surface ion adsorption sites of the NS structure and the occurrence of local electric field enhancement over the sharp edges and corners of WO3 NSs.

ZnT-1 enhances the activity and surface expression of T-type calcium channels through activation of Ras-ERK signaling.

PubMed

Mor, Merav; Beharier, Ofer; Levy, Shiri; Kahn, Joy; Dror, Shani; Blumenthal, Daniel; Gheber, Levi A; Peretz, Asher; Katz, Amos; Moran, Arie; Etzion, Yoram

2012-07-15

Zinc transporter-1 (ZnT-1) is a putative zinc transporter that confers cellular resistance from zinc toxicity. In addition, ZnT-1 has important regulatory functions, including inhibition of L-type calcium channels and activation of Raf-1 kinase. Here we studied the effects of ZnT-1 on the expression and function of T-type calcium channels. In Xenopus oocytes expressing voltage-gated calcium channel (CaV) 3.1 or CaV3.2, ZnT-1 enhanced the low-threshold calcium currents (I(caT)) to 182 ± 15 and 167.95 ± 9.27% of control, respectively (P < 0.005 for both channels). As expected, ZnT-1 also enhanced ERK phosphorylation. Coexpression of ZnT-1 and nonactive Raf-1 blocked the ZnT-1-mediated ERK phosphorylation and abolished the ZnT-1-induced augmentation of I(caT). In mammalian cells (Chinese hamster ovary), coexpression of CaV3.1 and ZnT-1 increased the I(caT) to 166.37 ± 6.37% compared with cells expressing CaV3.1 alone (P < 0.01). Interestingly, surface expression measurements using biotinylation or total internal reflection fluorescence microscopy indicated marked ZnT-1-induced enhancement of CaV3.1 surface expression. The MEK inhibitor PD-98059 abolished the ZnT-1-induced augmentation of surface expression of CaV3.1. In cultured murine cardiomyocytes (HL-1 cells), transient exposure to zinc, leading to enhanced ZnT-1 expression, also enhanced the surface expression of endogenous CaV3.1 channels. Consistently, in these cells, endothelin-1, a potent activator of Ras-ERK signaling, enhanced the surface expression of CaV3.1 channels in a PD-98059-sensitive manner. Our findings indicate that ZnT-1 enhances the activity of CaV3.1 and CaV3.2 through activation of Ras-ERK signaling. The augmentation of CaV3.1 currents by Ras-ERK activation is associated with enhanced trafficking of the channel to the plasma membrane.

Modeling pulmonary fibrosis by abnormal expression of telomerase/apoptosis/collagen V in experimental usual interstitial pneumonia

PubMed Central

Parra, E.R.; Pincelli, M.S.; Teodoro, W.R.; Velosa, A.P.P.; Martins, V.; Rangel, M.P.; Barbas-Filho, J.V.; Capelozzi, V.L.

2014-01-01

Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis. PMID:24919172

HCV proteins and immunoglobulin variable gene (IgV) subfamilies in HCV-induced type II mixed cryoglobulinemia: a concurrent pathogenetic role.

PubMed

Sautto, Giuseppe; Mancini, Nicasio; Solforosi, Laura; Diotti, Roberta A; Clementi, Massimo; Burioni, Roberto

2012-01-01

The association between hepatitis C virus (HCV) infection and type II mixed cryoglobulinemia (MCII) is well established, but the role played by distinct HCV proteins and by specific components of the anti-HCV humoral immune response remains to be clearly defined. It is widely accepted that HCV drives the expansion of few B-cell clones expressing a restricted pool of selected immunoglobulin variable (IgV) gene subfamilies frequently endowed with rheumatoid factor (RF) activity. Moreover, the same IgV subfamilies are frequently observed in HCV-transformed malignant B-cell clones occasionally complicating MCII. In this paper, we analyze both the humoral and viral counterparts at the basis of cryoglobulins production in HCV-induced MCII, with particular attention reserved to the single IgV subfamilies most frequently involved.

HCV Proteins and Immunoglobulin Variable Gene (IgV) Subfamilies in HCV-Induced Type II Mixed Cryoglobulinemia: A Concurrent Pathogenetic Role

PubMed Central

Sautto, Giuseppe; Mancini, Nicasio; Solforosi, Laura; Diotti, Roberta A.; Clementi, Massimo; Burioni, Roberto

2012-01-01

The association between hepatitis C virus (HCV) infection and type II mixed cryoglobulinemia (MCII) is well established, but the role played by distinct HCV proteins and by specific components of the anti-HCV humoral immune response remains to be clearly defined. It is widely accepted that HCV drives the expansion of few B-cell clones expressing a restricted pool of selected immunoglobulin variable (IgV) gene subfamilies frequently endowed with rheumatoid factor (RF) activity. Moreover, the same IgV subfamilies are frequently observed in HCV-transformed malignant B-cell clones occasionally complicating MCII. In this paper, we analyze both the humoral and viral counterparts at the basis of cryoglobulins production in HCV-induced MCII, with particular attention reserved to the single IgV subfamilies most frequently involved. PMID:22690241

Evaluation of band alignment of α-Ga2O3/α-(Al x Ga1‑ x )2O3 heterostructures by X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Uchida, Takayuki; Jinno, Riena; Takemoto, Shu; Kaneko, Kentaro; Fujita, Shizuo

2018-04-01

The band alignment at an α-Ga2O3/α-(Al x Ga1‑ x )2O3 heterointerface, with different Al compositions (x), grown on a c-plane sapphire substrate was evaluated by X-ray photoelectron spectroscopy. The experimental results show that the heterointerface has the type-I band discontinuity with the valence band offsets of 0.090, 0.12, and 0.14 eV, and the conduction band offsets of 0.34, 0.79, and 1.87 eV, for x values of 0.1, 0.4, and 0.8, respectively. The small band offset for the valence band is attributed to the fact that the valence band of oxides is constituted by the localized O 2p level, which is dominated by the nature of oxygen atoms. The type-I band discontinuity is desirable for a variety of heterostructure devices.

Effect of the Heat-Treated Ti6Al4V Alloy on the Fibroblastic Cell Response

PubMed Central

Chávez-Díaz, Mercedes Paulina; Escudero-Rincón, María Lorenza; Arce-Estrada, Elsa Miriam; Cabrera-Sierra, Román

2017-01-01

Two heat treatments were carried out below (Ti6Al4V800) and above (Ti6Al4V1050) Ti6Al4V beta-phase transformation temperature (980 °C), with the purpose of studying the effect of microstructure on the adhesion and proliferation of fibroblast cells, as well as their electrochemical behavior. These alloys were seeded with 10,000 L929 fibroblast cells and immersed for 7 days in the cell culture at 37 °C, pH 7.40, 5% CO2 and 100% relative humidity. Cell adhesion was characterized by Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS) techniques. Polygonal and elongated cell morphology was observed independent of Ti6Al4V microstructure. Besides, C, O, P, S, Na and Cl signals were detected by Energy Dispersive X-Ray Spectroscopy (EDX), associated with the synthesis of organic compounds excreted by the cells, including protein adsorption from the medium. In certain areas on Ti6Al4V and Ti6Al4V800 alloys, cells were agglomerated (island type), likely related to the globular microstructure; meanwhile, larger cellular coverage is shown for Ti6Al4V1050 alloy, forming more than one layer on the surface, where only Ca was recorded. Impedance diagrams showed a similar passive behavior for the different Ti6Al4V alloys, mainly due to TiO2 overlaying the contribution of the organic compounds excreted by fibroblast cells. PMID:29301205

[An investigation of trichloroethylene-induced effects on histone methylation in L-02 hepatic cells].

PubMed

Deng, R X; Ren, X H; Ruan, J W; Zheng, J; Zhong, J C; Lu, W X; Zou, X Q; Liu, J J

2017-04-06

Objective: To further explore TCE-induced hepatotoxicity and its mechanisms by identification of trichloroethylene (TCE) induced abnormal histone methylation in human liver cells. Methods: L-02 cells were treated with 0 and 8 mmol/L TCE for 24 h. Histones were extracted by acid. Liquid chromatography electrospray ionization tandem mass spectrometry (ESI-LC-MS/MS) were used to identify and quantify TCE related histone methylations. TCE induced abnormal methylation of H3K79 me2 and H3K79 me3 were validated by Western blot analysis. The further analysis of the function of histone abnormal methylation modifications were done by single cell gel electrophoresis (SCGE) and Western blot analysis of p53 and ɤH2AX. Results: After treatment with TCE for 24 h in L-02 cells, the 36 TCE related histone methylation sites in 28 peptide segments were identified by MS. After treatment with TCE in concentrations of 0 and 8.0 mmol/L in L-02 cells for 24 h, the relative expression level of histone H3K79 me3 were 1.00±0.06, 0.70±0.09 ( t= 15.01, P= 0.015); the relative expression level of histone H3K79 me2 were 1.00±0.05, 0.74±0.07 ( t= 16.69, P= 0.018); the Olive Tail Moment about DNA damage were 1.46±0.28, 3.12± 0.68 ( t= 15.22, P= 0.018); the relative expression levels of p53 were 1.00±0.04, 1.24±0.04 ( t= 18.71, P= 0.012); and the relative expression levels of ɤH2AX were 1.00 ± 0.03, 1.56 ± 0.11 ( t= 8.32, P= 0 045). Conclusion: TCE can induce changes in the relative expression level of H3K79 me2 and H3K79 me3 in L-02 cell, and induce DNA damage, suggesting that TCE may induce changes in the relative expression level of H3K79 me2 and H3K79 me3 by DNA damage.

Reduced N-Type Ca2+ Channels in Atrioventricular Ganglion Neurons Are Involved in Ventricular Arrhythmogenesis.

PubMed

Zhang, Dongze; Tu, Huiyin; Cao, Liang; Zheng, Hong; Muelleman, Robert L; Wadman, Michael C; Li, Yu-Long

2018-01-15

Attenuated cardiac vagal activity is associated with ventricular arrhythmogenesis and related mortality in patients with chronic heart failure. Our recent study has shown that expression of N-type Ca 2+ channel α-subunits (Ca v 2.2-α) and N-type Ca 2+ currents are reduced in intracardiac ganglion neurons from rats with chronic heart failure. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Ventricular myocardium receives projection of neuronal terminals only from the AVG. In this study we tested whether a decrease in N-type Ca 2+ channels in AVG neurons contributes to ventricular arrhythmogenesis. Lentiviral Ca v 2.2-α shRNA (2 μL, 2×10 7  pfu/mL) or scrambled shRNA was in vivo transfected into rat AVG neurons. Nontransfected sham rats served as controls. Using real-time single-cell polymerase chain reaction and reverse-phase protein array, we found that in vivo transfection of Ca v 2.2-α shRNA decreased expression of Ca v 2.2-α mRNA and protein in rat AVG neurons. Whole-cell patch-clamp data showed that Ca v 2.2-α shRNA reduced N-type Ca 2+ currents and cell excitability in AVG neurons. The data from telemetry electrocardiographic recording demonstrated that 83% (5 out of 6) of conscious rats with Ca v 2.2-α shRNA transfection had premature ventricular contractions ( P <0.05 versus 0% of nontransfected sham rats or scrambled shRNA-transfected rats). Additionally, an index of susceptibility to ventricular arrhythmias, inducibility of ventricular arrhythmias evoked by programmed electrical stimulation, was higher in rats with Ca v 2.2-α shRNA transfection compared with nontransfected sham rats and scrambled shRNA-transfected rats. A decrease in N-type Ca 2+ channels in AVG neurons attenuates vagal control of ventricular myocardium, thereby initiating ventricular arrhythmias. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Important Role for the Transmembrane Domain of Severe Acute Respiratory Syndrome Coronavirus Spike Protein during Entry

PubMed Central

Broer, Rene; Boson, Bertrand; Spaan, Willy; Cosset, François-Loïc; Corver, Jeroen

2006-01-01

The spike protein (S) of severe acute respiratory syndrome coronavirus (SARS-CoV) is responsible for receptor binding and membrane fusion. It contains a highly conserved transmembrane domain that consists of three parts: an N-terminal tryptophan-rich domain, a central domain, and a cysteine-rich C-terminal domain. The cytoplasmic tail of S has previously been shown to be required for assembly. Here, the roles of the transmembrane and cytoplasmic domains of S in the infectivity and membrane fusion activity of SARS-CoV have been studied. SARS-CoV S-pseudotyped retrovirus (SARSpp) was used to measure S-mediated infectivity. In addition, the cell-cell fusion activity of S was monitored by a Renilla luciferase-based cell-cell fusion assay. Svsv-cyt, an S chimera with a cytoplasmic tail derived from vesicular stomatitis virus G protein (VSV-G), and Smhv-tmdcyt, an S chimera with the cytoplasmic and transmembrane domains of mouse hepatitis virus, displayed wild-type-like activity in both assays. Svsv-tmdcyt, a chimera with the cytoplasmic and transmembrane domains of VSV-G, was impaired in the SARSpp and cell-cell fusion assays, showing 3 to 25% activity compared to the wild type, depending on the assay and the cells used. Examination of the oligomeric state of the chimeric S proteins in SARSpp revealed that Svsv-tmdcyt trimers were less stable than wild-type S trimers, possibly explaining the lowered fusogenicity and infectivity. PMID:16415007

Clinical utility of serum samples for human parechovirus type 3 infection in neonates and young infants: The 2014 epidemic in Japan.

PubMed

Aizawa, Yuta; Suzuki, Yuko; Watanabe, Kanako; Oishi, Tomohiro; Saitoh, Akihiko

2016-02-01

During the 2014 human parechovirus type 3 (HPeV3) epidemic in Niigata, Japan, this prospective observational study identified HPeV3 from 43/85 (51%) febrile young infants <4 months using PCR analysis of serum (n = 42) and/or cerebrospinal fluid (CSF) (n = 32) and genetic sequencing of the VP1 region of HPeV3. HPeV3-infected patients (median age, 32 days; range, 4-113 days) were diagnosed as having sepsis (79%), sepsis-like syndrome (19%), or encephalitis with septic shock (2%). Other than fever, mottled skin (67%) was significantly more frequent in HPeV3-infected patients than other virus-infected patients (P = 0.005). The rate of HPeV3 RNA detection in CSF without pleocytosis was high (88%; 28/32). Among the 32 patients whose serum and CSF samples were available, all patients were positive for serum PCR; however, 4 (12%) patients were negative for CSF PCR. Serum HPeV3 RNA level on admission was associated with younger age (P = 0.002), bad temper (P = 0.041), and grunting (P = 0.008). Among 6 patients with sequential data on serum HPeV3 RNA level, levels decreased rapidly without specific therapy. In conclusion, serum samples at disease onset are the most useful compared to CSF in detection of HPeV RNA and serum HPeV3 RNA level on admission was associated with important clinical manifestations in HPeV3-infected patients. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Cathode limited charge transport and performance of thin-film rechargeable lithium batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bates, J.B.; Hart, F.X.; Lubben, D.

1994-11-01

Several types of thin-film rechargeable batteries based on lithium metal anodes and amorphous V{sub 2}O{sub 5} (aV{sub 2}O{sub 5}), LiMn{sub 2}O{sub 4}, and LiCoO{sub 2} cathodes have been investigated in this laboratory. In all cases, the current density of these cells is limited by lithium ion transport in the cathodes. This paper, discusses sources of this impedance in Li-aV{sub 2}O{sub 5} and Li-LiMn{sub 2}O{sub 4} thin-film cells and their effect on cell performance.

Radiation-quality dependent cellular response in mutation induction in normal human cells.

PubMed

Suzuki, Masao; Tsuruoka, Chizuru; Uchihori, Yukio; Kitamura, Hisashi; Liu, Cui Hua

2009-09-01

We studied cellular responses in normal human fibroblasts induced with low-dose (rate) or low-fluence irradiations of different radiation types, such as gamma rays, neutrons and high linear energy transfer (LET) heavy ions. The cells were pretreated with low-dose (rate) or low-fluence irradiations (approximately 1 mGy/7-8 h) of 137Cs gamma rays, 241Am-Be neutrons, helium, carbon and iron ions before irradiations with an X-ray challenging dose (1.5 Gy). Helium (LET = 2.3 keV/microm), carbon (LET = 13.3 keV/microm) and iron (LET = 200 keV/microm) ions were produced by the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. No difference in cell-killing effect, measured by a colony forming assay, was observed among the pretreatment with different radiation types. In mutation induction, which was detected in the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus to measure 6-thioguanine resistant clones, there was no difference in mutation frequency induced by the X-ray challenging dose between unpretreated and gamma-ray pretreated cells. In the case of the pretreatment of heavy ions, X-ray-induced mutation was around 1.8 times higher in helium-ion pretreated and 4.0 times higher in carbon-ion pretreated cells than in unpretreated cells (X-ray challenging dose alone). However, the mutation frequency in cells pretreated with iron ions was the same level as either unpretreated or gamma-ray pretreated cells. In contrast, it was reduced at 0.15 times in cells pretreated with neutrons when compared to unpretreated cells. The results show that cellular responses caused by the influence of hprt mutation induced in cells pretreated with low-dose-rate or low-fluence irradiations of different radiation types were radiation-quality dependent manner.

Beyond Columnar Organization: Cell Type- and Target Layer-Specific Principles of Horizontal Axon Projection Patterns in Rat Vibrissal Cortex

PubMed Central

Narayanan, Rajeevan T.; Egger, Robert; Johnson, Andrew S.; Mansvelder, Huibert D.; Sakmann, Bert; de Kock, Christiaan P.J.; Oberlaender, Marcel

2015-01-01

Vertical thalamocortical afferents give rise to the elementary functional units of sensory cortex, cortical columns. Principles that underlie communication between columns remain however unknown. Here we unravel these by reconstructing in vivo-labeled neurons from all excitatory cell types in the vibrissal part of rat primary somatosensory cortex (vS1). Integrating the morphologies into an exact 3D model of vS1 revealed that the majority of intracortical (IC) axons project far beyond the borders of the principal column. We defined the corresponding innervation volume as the IC-unit. Deconstructing this structural cortical unit into its cell type-specific components, we found asymmetric projections that innervate columns of either the same whisker row or arc, and which subdivide vS1 into 2 orthogonal [supra-]granular and infragranular strata. We show that such organization could be most effective for encoding multi whisker inputs. Communication between columns is thus organized by multiple highly specific horizontal projection patterns, rendering IC-units as the primary structural entities for processing complex sensory stimuli. PMID:25838038

Identification of Yeast V-ATPase Mutants by Western Blots Analysis of Whole Cell Lysates

NASA Astrophysics Data System (ADS)

Parra-Belky, Karlett

2002-11-01

A biochemistry laboratory was designed for an undergraduate course to help students better understand the link between molecular engineering and biochemistry. Students identified unknown yeast strains with high specificity using SDS-PAGE and Western blot analysis of whole cell lysates. This problem-solving exercise is a common application of biochemistry in biotechnology research. Three different strains were used: a wild-type and two mutants for the proton pump vacuolar ATPase (V-ATPase). V-ATPases are multisubunit enzymes and the mutants used were deletion mutants; each lacked one structural gene of the complex. After three, three-hour labs, mutant strains were easily identified by the students and distinguished from wild-type cells analyzing the pattern of SDS-PAGE distribution of proteins. Identifying different subunits of one multimeric protein allowed for discussion of the structure and function of this metabolic enzyme, which captured the interest of the students. The experiment can be adapted to other multimeric protein complexes and shows improvement of the described methodology over previous reports, perhaps because the problem and its solution are representative of the type of techniques currently used in research labs.

Everolimus selectively targets vemurafenib resistant BRAFV600E melanoma cells adapted to low pH.

PubMed

Ruzzolini, Jessica; Peppicelli, Silvia; Andreucci, Elena; Bianchini, Francesca; Margheri, Francesca; Laurenzana, Anna; Fibbi, Gabriella; Pimpinelli, Nicola; Calorini, Lido

2017-11-01

Vemurafenib, a BRAF inhibitor, elicits in ∼80% of BRAF V600E -mutant melanoma patients a transient anti-tumor response which precedes the emergence of resistance. We tested whether an acidic tumor microenvironment may favor a BRAF inhibitor resistance. A375M6 BRAF V600E melanoma cells, either exposed for a short period or chronically adapted to an acidic medium, showed traits compatible with an epithelial-mesenchymal transition, reduced proliferation and high resistance to apoptosis. Both types of acidic cells treated with vemurafenib did not change their proliferation, distribution in cell cycle and level of p-AKT, in contrast to cells grown at standard pH, which showed reduced proliferation, cell cycle arrest and ERK/AKT inhibition. Even after treatment with trametinib (MEK inhibitor) acidic cell features did not change. Then, since both types of acidic cells exhibited high p-p70S6K, i.e. active mTOR signaling, we tested everolimus, an mTOR inhibitor, which was efficient in inducing apoptosis in acidic cells without affecting melanoma cells grown at standard pH. Our results indicate that an acidic microenvironment may cooperate in inducing a BRAF inhibitor resistance in melanoma cells and a combined therapy with everolimus could be used to overcome that resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissecting the role of matrix metalloproteinases (MMP) and integrin alpha(v)beta3 in angiogenesis in vitro: absence of hemopexin C domain bioactivity, but membrane-Type 1-MMP and alpha(v)beta3 are critical.

PubMed

Nisato, Riccardo E; Hosseini, Ghamartaj; Sirrenberg, Christian; Butler, Georgina S; Crabbe, Thomas; Docherty, Andrew J P; Wiesner, Matthias; Murphy, Gillian; Overall, Christopher M; Goodman, Simon L; Pepper, Michael S

2005-10-15

Matrix metalloproteinase (MMP)-2 and its hemopexin C domain autolytic fragment (also called PEX) have been proposed to be crucial for angiogenesis. Here, we have investigated the dependency of in vitro angiogenesis on MMP-mediated extracellular proteolysis and integrin alpha(v)beta3-mediated cell adhesion in a three-dimensional collagen I model. The hydroxamate-based synthetic inhibitors BB94, CT1399, and CT1847 inhibited endothelial cell invasion, as did neutralizing anti-membrane-type 1-MMP (MT1-MMP) antibodies and tissue inhibitor of MMP (TIMP)-2 and TIMP-3 but not TIMP-1. This confirmed the pivotal importance of MT1-MMP over other MMPs in this model. Invasion was also inhibited by a nonpeptidic antagonist of integrin alpha(v)beta3, EMD 361276. Although PEX strongly inhibited pro-MMP-2 activation, when contaminating lipopolysaccharide was neutralized, PEX neither affected angiogenesis nor bound integrin alpha(v)beta(3). Moreover, no specific binding of pro-MMP-2 to integrin alpha(v)beta3 was found, whereas only one out of four independently prepared enzymatically active MMP-2 preparations could bind integrin alpha(v)beta3 , and this in a PEX-independent manner. Likewise, integrin alpha(v)beta3 -expressing cells did not bind MMP-2-coated surfaces. Hence, these findings show that endothelial cell invasion of collagen I gels is MT1-MMP and alpha(v)beta3 - dependent but MMP-2 independent and does not support a role for PEX in alpha(v)beta3 integrin binding or in modulating angiogenesis in this system.

Notch signaling: its roles and therapeutic potential in hematological malignancies

PubMed Central

Gu, Yisu

2016-01-01

Notch is a highly conserved signaling system that allows neighboring cells to communicate, thereby controlling their differentiation, proliferation and apoptosis, with the outcome of its activation being highly dependent on signal strength and cell type. As such, there is growing evidence that disturbances in physiological Notch signaling contribute to cancer development and growth through various mechanisms. Notch was first reported to contribute to tumorigenesis in the early 90s, through identification of the involvement of the Notch1 gene in the chromosomal translocation t(7;9)(q34;q34.3), found in a small subset of T-cell acute lymphoblastic leukemia. Since then, Notch mutations and aberrant Notch signaling have been reported in numerous other precursor and mature hematological malignancies, of both myeloid and lymphoid origin, as well as many epithelial tumor types. Of note, Notch has been reported to have both oncogenic and tumor suppressor roles, dependent on the cancer cell type. In this review, we will first give a general description of the Notch signaling pathway, and its physiologic role in hematopoiesis. Next, we will review the role of aberrant Notch signaling in several hematological malignancies. Finally, we will discuss current and potential future therapeutic approaches targeting this pathway. PMID:26934331

Polymorphisms in the lcrV gene of Yersinia enterocolitica and their effect on plague protective immunity.

PubMed

Miller, Nathan C; Quenee, Lauriane E; Elli, Derek; Ciletti, Nancy A; Schneewind, Olaf

2012-04-01

Current efforts to develop plague vaccines focus on LcrV, a polypeptide that resides at the tip of type III secretion needles. LcrV-specific antibodies block Yersinia pestis type III injection of Yop effectors into host immune cells, thereby enabling phagocytes to kill the invading pathogen. Earlier work reported that antibodies against Y. pestis LcrV cannot block type III injection by Yersinia enterocolitica strains and suggested that lcrV polymorphisms may provide for escape from LcrV-mediated plague immunity. We show here that polyclonal or monoclonal antibodies raised against Y. pestis KIM D27 LcrV (LcrV(D27)) bind LcrV from Y. enterocolitica O:9 strain W22703 (LcrV(W22703)) or O:8 strain WA-314 (LcrV(WA-314)) but are otherwise unable to block type III injection by Y. enterocolitica strains. Replacing the lcrV gene on the pCD1 virulence plasmid of Y. pestis KIM D27 with either lcrV(W22703) or lcrV(WA-314) does not affect the ability of plague bacteria to secrete proteins via the type III pathway, to inject Yops into macrophages, or to cause lethal plague infections in mice. LcrV(D27)-specific antibodies blocked type III injection by Y. pestis expressing lcrV(W22703) or lcrV(WA-314) and protected mice against intravenous lethal plague challenge with these strains. Thus, although antibodies raised against LcrV(D27) are unable to block the type III injection of Y. enterocolitica strains, expression of lcrV(W22703) or lcrV(WA-314) in Y. pestis did not allow these strains to escape LcrV-mediated plague protective immunity in the intravenous challenge model.

Measles virus C protein suppresses gamma-activated factor formation and virus-induced cell growth arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokota, Shin-ichi; Okabayashi, Tamaki; Fujii, Nobuhiro, E-mail: fujii@sapmed.ac.j

2011-05-25

Measles virus (MeV) produces two accessory proteins, V and C, from the P gene. These accessory proteins have been reported to contribute to efficient virus proliferation through the modulation of host cell events. Our previous paper described that Vero cell-adapted strains of MeV led host cells to growth arrest through the upregulation of interferon regulatory factor 1 (IRF-1), and wild strains did not. In the present study, we found that C protein expression levels varied among MeV strains in infected SiHa cells. C protein levels were inversely correlated with IRF-1 expression levels and with cell growth arrest. Forced expression ofmore » C protein released cells from growth arrest. C-deficient recombinant virus efficiently upregulated IRF-1 and caused growth arrest more efficiently than the wild-type virus. C protein preferentially bound to phosphorylated STAT1 and suppressed STAT1 dimer formation. We conclude that MeV C protein suppresses IFN-{gamma} signaling pathway via inhibition of phosphorylated STAT1 dimerization.« less

Anti-CD22 and anti-CD79b antibody-drug conjugates preferentially target proliferating B cells.

PubMed

Fuh, Franklin K; Looney, Caroline; Li, Dongwei; Poon, Kirsten A; Dere, Randall C; Danilenko, Dimitry M; McBride, Jacqueline; Reed, Chae; Chung, Shan; Zheng, Bing; Mathews, William Rodney; Polson, Andrew; Prabhu, Saileta; Williams, Marna

2017-04-01

CD22 and CD79b are cell-surface receptors expressed on B-cell-derived malignancies such as non-Hodgkin's lymphoma (NHL). An anti-mitotic agent, monomethyl auristatin E, was conjugated to anti-CD22 and anti-CD79b antibodies to develop target-specific therapies for NHL. The mechanism of action (MOA) and pharmacological and pharmacokinetic (PK) profiles of these antibody-drug conjugates (ADCs) were investigated in cynomolgus monkeys. Animals were administered anti-CD22 or anti-CD79b ADCs, respective unconjugated antibodies or vehicle. Pharmacodynamic effects on total and proliferating B cells and serum PK were then assessed. Antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) of the ADCs were evaluated in vitro. Depletion of B cells was observed after administration of either ADC or the respective unconjugated antibodies. An extended duration of depletion was observed in animals administered ADCs. Similarly, preferential depletion of proliferating B cells in blood and germinal centre B cells in spleen were only observed in animals administered ADCs. Serum PK profiles of ADCs and respective unconjugated antibodies were comparable. In vitro, anti-human CD22 and anti-human CD79b antibodies showed no or only moderate ADCC activity, respectively; neither antibody had CDC activity. The findings support the proposed MOA: initial depletion of total B cells by antibody-mediated opsonization, followed by preferential, sustained depletion of proliferating B cells by the auristatin conjugate due to its anti-mitotic action. Delivering potent anti-mitotic agents to B cells via the specificity of monoclonal antibodies provides a means to eliminate pathogenic B cells in NHL with improved risk-benefit profiles over traditional chemotherapeutics. © 2016 Genentech. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Fabrication of Semi-Transparent Photovoltaic Cell by a Cost-Effective Technique

NASA Astrophysics Data System (ADS)

Nithyayini, K. N.; Ramasesha, Sheela K.

2015-09-01

Semi-transparent inorganic thin film PV cells have been fabricated using n-type (CdS) and p-type (CdTe) semiconductors. Large area devices which can be used as windows and skylights in buildings can be fabricated using cost effective solution processes. The device structure is Glass/TCO/CdTe/CdS/TCO. Chemically stable CdS and CdTe layers are deposited at temperatures 353 K to 373 K (80 °C to 100 °C) under controlled pH. The CdCl2 activation is carried out followed by air annealing. The p-n junction is formed by sintering the device at 673 K to 723 K (400 °C to 450 °C). The characterization of cells is carried out using XRD, SEM, AFM, and UV-Visible spectroscopy. The thickness of the cell is ~600 nm. The band gap values are 2.40 eV for CdS and 1.36 eV for CdTe with transmittance of about 70 pct in the visible region. Under 1.5 AM solar spectrum, V oc, and I sc of the initial device are 3.56e-01 V and 6.20e-04 A, respectively.

Artificial Intelligence vs. Statistical Modeling and Optimization of Continuous Bead Milling Process for Bacterial Cell Lysis.

PubMed

Haque, Shafiul; Khan, Saif; Wahid, Mohd; Dar, Sajad A; Soni, Nipunjot; Mandal, Raju K; Singh, Vineeta; Tiwari, Dileep; Lohani, Mohtashim; Areeshi, Mohammed Y; Govender, Thavendran; Kruger, Hendrik G; Jawed, Arshad

2016-01-01

For a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD) was studied in a continuous bead milling process. A full factorial response surface methodology (RSM) design was employed and compared to artificial neural networks coupled with genetic algorithm (ANN-GA). Significant process variables, cell slurry feed rate (A), bead load (B), cell load (C), and run time (D), were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v), cell loading OD 600 nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN-GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h): 258.08, bead loading (%, v/v): 80%, cell loading (OD 600 nm ): 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN) in combination with evolutionary optimization (GA) for representing undefined biological functions which is the case for common industrial processes involving biological moieties.

Artificial Intelligence vs. Statistical Modeling and Optimization of Continuous Bead Milling Process for Bacterial Cell Lysis

PubMed Central

Haque, Shafiul; Khan, Saif; Wahid, Mohd; Dar, Sajad A.; Soni, Nipunjot; Mandal, Raju K.; Singh, Vineeta; Tiwari, Dileep; Lohani, Mohtashim; Areeshi, Mohammed Y.; Govender, Thavendran; Kruger, Hendrik G.; Jawed, Arshad

2016-01-01

For a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD) was studied in a continuous bead milling process. A full factorial response surface methodology (RSM) design was employed and compared to artificial neural networks coupled with genetic algorithm (ANN-GA). Significant process variables, cell slurry feed rate (A), bead load (B), cell load (C), and run time (D), were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v), cell loading OD600 nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN-GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h): 258.08, bead loading (%, v/v): 80%, cell loading (OD600 nm): 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN) in combination with evolutionary optimization (GA) for representing undefined biological functions which is the case for common industrial processes involving biological moieties. PMID:27920762

Universality of Non-Ohmic Shunt Leakage in Thin-Film Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongaonkar, S.; Servaites, J.D.; Ford, G.M.

2010-01-01

We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In,Ga)Se 2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V<~0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (I sh) , across all three solar cell types considered, is characterized by the following commonmore » phenomenological features: (a) voltage symmetry about V=0 , (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism.« less

Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

PubMed

Unterweger, Daniel; Kitaoka, Maya; Miyata, Sarah T; Bachmann, Verena; Brooks, Teresa M; Moloney, Jessica; Sosa, Oscar; Silva, David; Duran-Gonzalez, Jorge; Provenzano, Daniele; Pukatzki, Stefan

2012-01-01

The type VI secretion system (T6SS) mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria) and a eukaryote (the social amoeba Dictyostelium discoideum). Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

The BRAF{sup T1799A} mutation confers sensitivity of thyroid cancer cells to the BRAF{sup V600E} inhibitor PLX4032 (RG7204)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing, Joanna; Liu, Ruixin; Xing, Mingzhao

2011-01-28

Research highlights: {yields} Exciting therapeutic potential has been recently reported for the BRAF{sup V600E} inhibitor PLX4032 in melanoma. {yields} We tested the effects of PLX4032 on the growth of thyroid cancer cells which often harbor the BRAF{sup V600E} mutation. {yields} We observed a potent BRAF{sup V600E}-dependent inhibition of thyroid cancer cells by PLX4032. {yields} We thus demonstrated an important therapeutic potential of PLX4032 for thyroid cancer. -- Abstract: Aberrant signaling of the Ras-Raf-MEK-ERK (MAP kinase) pathway driven by the mutant kinase BRAF{sup V600E}, as a result of the BRAF{sup T1799A} mutation, plays a fundamental role in thyroid tumorigenesis. This studymore » investigated the therapeutic potential of a BRAF{sup V600E}-selective inhibitor, PLX4032 (RG7204), for thyroid cancer by examining its effects on the MAP kinase signaling and proliferation of 10 thyroid cancer cell lines with wild-type BRAF or BRAF{sup T1799A} mutation. We found that PLX4032 could effectively inhibit the MAP kinase signaling, as reflected by the suppression of ERK phosphorylation, in cells harboring the BRAF{sup T1799A} mutation. PLX4032 also showed a potent and BRAF mutation-selective inhibition of cell proliferation in a concentration-dependent manner. PLX4032 displayed low IC{sub 50} values (0.115-1.156 {mu}M) in BRAF{sup V600E} mutant cells, in contrast with wild-type BRAF cells that showed resistance to the inhibitor with high IC{sub 50} values (56.674-1349.788 {mu}M). Interestingly, cells with Ras mutations were also sensitive to PLX4032, albeit moderately. Thus, this study has confirmed that the BRAF{sup T1799A} mutation confers cancer cells sensitivity to PLX4032 and demonstrated its specific potential as an effective and BRAF{sup T1799A} mutation-selective therapeutic agent for thyroid cancer.« less

[Results of the SHOP LNHB98 (LMB89) trial in pediatric patients with B-cell non-Hodgkin's lymphoma].

PubMed

Forns, Marga; Javier, Germán; Estella, Jesús; Fernández-Delgado, Rafael; Gallego, Soledad; García-Miguel, Purificación; Indiano, José M; Navajas, Aurora; Pardo, Nuria

2007-05-05

After the good results obtained by the Société Française d'Oncologie Pédiatrique (SFOP) regarding the pediatric B-type non-Hodgkin's (Burkitt and large B-cell) lymphoma and L3 leukemia, the Sociedad Española de Hematología y Oncología Pediátricas (SHOP) decided to use the same treatment protocol. Pediatric patients diagnosed with B-type non-Hodgkin's lymphoma without a previous history of malignant diseases were eligible for this study. They were classified in 3 groups of risk: group A (resected stage I and abdominal stage II), group B (not eligible for groups A or C), and group C (with central nervous system involvement and L3 leukemia). All received treatment according to the SFOP's LMB89 protocol. A total of 153 patients were considered in this multicenter, prospective and non-randomized trial (1997-2005). The global and event-free survival (EFS) were found to be of 88% (0.88; 95% confidence interval [CI], 0.83-0.93) and 85% (0.85; 95% CI, 0.79-0.90), respectively. The EFS was 100% for the group A (n = 16), 86% (0.86; 95% CI, 0.79-0.92) for the group B (n = 113), and 68% (0.68; 95% CI, 0.49-0.86) for the group C (n = 24). The results confirm the good efficiency of the LMB89 protocol for treating B-cell lymphoma and L3 leukemia, despite having diminished the treatment intensity in the less risk groups. The worst prognostic factor was found to be a central nervous system involvement, whereas being younger than 10 years was confirmed to be a favorable prognostic factor. In addition, no differences were evidenced between Burkitt and large B-cell lymphoma.

Effects of interleukins on connective tissue type mast cells co-cultured with fibroblasts.

PubMed Central

Levi-Schaffer, F; Segal, V; Shalit, M

1991-01-01

We investigated the effects of interleukin-2 (IL-2), interleukin-3 (IL-3) and interleukin-4 (IL-4) on mouse and rat peritoneal mast cells (MC) co-cultured with 3T3 fibroblasts (MC/3T3). The continuous presence of these cytokines for 7-9 days in the culture media was neither toxic nor caused proliferation of MC, as determined by the stability of MC numbers in culture. Long-term incubation of mouse MC/3T3 with IL-2 (100 U/ml), IL-3 (50 U/ml), IL-4 (50 U/ml) or a mixture of IL-3 and IL-4 (25 U/ml) induced an increase in basal histamine release of 79.3 +/- 19.0%, 41.0 +/- 17.3%, 25.2 +/- 10.4% and 30.2 +/- 3.2%, respectively, over control cells incubated with medium alone. When rat MC/3T3 were incubated for 7 days with the various interleukins an enhancement in histamine release similar to that observed with mouse MC/3T3 was found. Preincubation (1 hr) of rat MC/3T3 with interleukins prior to immunological activation with anti-IgE antibodies enhanced histamine release. The highest effect was observed with IL-3 + IL-4 (60.4 +/- 10.8% increase) followed by IL-2 (51.5 +/- 4.5%), IL-4 (28.6 +/- 10.3%) and IL-3 (13.2 +/- 4.2%). This study demonstrates that when mouse and rat peritoneal MC are cultured with fibroblasts in the presence of interleukins they do not proliferate, suggesting that they preserve their connective tissue type MC phenotype. Moreover, interleukins display a pro-inflammatory effect on these cells by enhancing both basal and anti-IgE-mediated histamine release. PMID:2016117

Generation and CRISPR/Cas9 editing of transformed progenitor B cells as a pseudo-physiological system to study DNA repair gene function in V(D)J recombination.

PubMed

Lenden Hasse, Hélène; Lescale, Chloé; Bianchi, Joy J; Yu, Wei; Bedora-Faure, Marie; Deriano, Ludovic

2017-12-01

Antigen receptor gene assembly is accomplished in developing lymphocytes by the V(D)J recombination reaction, which can be separated into two steps: DNA cleavage by the recombination-activating gene (RAG) nuclease and joining of DNA double strand breaks (DSBs) by components of the nonhomologous end joining (NHEJ) pathway. Deficiencies for NHEJ factors can result in immunodeficiency and a propensity to accumulate genomic instability, thus highlighting the importance of identifying all players in this process and deciphering their functions. Bcl2 transgenic v-Abl kinase-transformed pro-B cells provide a pseudo-physiological cellular system to study V(D)J recombination. Treatment of v-Abl/Bcl2 pro-B cells with the Abl kinase inhibitor Imatinib leads to G1 cell cycle arrest, the rapid induction of Rag1/2 gene expression and V(D)J recombination. In this system, the Bcl2 transgene alleviates Imatinib-induced apoptosis enabling the analysis of induced V(D)J recombination. Although powerful, the use of mouse models carrying the Bcl2 transgene for the generation of v-Abl pro-B cell lines is time and money consuming. Here, we describe a method for generating v-Abl/Bcl2 pro-B cell lines from wild type mice and for performing gene knock-out using episomal CRISPR/Cas9 targeting vectors. Using this approach, we generated distinct NHEJ-deficient pro-B cell lines and quantified V(D)J recombination levels in these cells. Furthermore, this methodology can be adapted to generate pro-B cell lines deficient for any gene suspected to play a role in V(D)J recombination, and more generally DSB repair. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Baker Lake, Northwest Territories, Canada. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F

DTIC Science & Technology

1972-01-13

8217.,7 ?5,Z : + . 95.8 , 995,3 9904. 940’ "b,= 9 . u 93,0 96.60* 300 V40 V203 V2i’ !5T V50 !5’ s4f WtD VDi It~ JT 73~T 77~’ *_ 200 94, 6,5 90,0197,3... 2048 / 47 1,.1 7,9 3 .4 4_ 711 59 51,4077 45 Z,3 0 5 51 44/ 43 3.0103 4 , 9 5 511 81 03 65 T31 105L I I 76 40/ 39 ,4 8,1 4ś 47[ 79 76 30/ $7 - , ,ilt s

Mitomycin C induces apoptosis in cultured corneal fibroblasts derived from type II granular corneal dystrophy corneas.

PubMed

Kim, Tae-im; Choi, Seung-il; Lee, Hyung Keun; Cho, Young Jae; Kim, Eung Kweon

2008-06-30

The present study investigated the effect of mitomycin C (MMC) on cell viability, apoptosis, and transforming growth factor beta-induced protein (TGFBIp) expression in cultured normal corneal fibroblasts and heterozygote or homozygote granular corneal dystrophy type II (GCD II) corneal fibroblasts. Keratocytes were obtained from normal cornea or from heterozygote or homozygote GCD II patients after lamellar or penetrating keratoplasty. To measure cell viability, corneal fibroblasts were incubated with 0.02% MMC for 3 h, 6 h, and 24 h or with 0%, 0.01%, 0.02%, and 0.04% MMC for 24 h and then tested using lactate dehydrogenase (LDH) and 3-[4,5-demethylthiazol-2,5-diphenyl-2H-tetrazolium bromide] (MTT) assays. To measure apoptosis, cells were analyzed by FACS analysis and annexin V staining. Bcl-xL, Bax, and TGFBI mRNA expression was measured using reverse transcription polymerase chain reaction (RT-PCR) assays. Cellular and media levels of TGFBIp protein were measured by immunoblotting. MTT and LDH assays showed that MMC reduced cell viability in all three cell types in a dose-dependent and time-dependent manner (p<0.05). FACS analysis and annexin V staining showed that MMC caused apoptosis with GCD II homozygote cells being most affected. RT-PCR analysis showed that MMC decreased Bcl-xL mRNA expression and increased Bax mRNA expression in all cell types. RT-PCR and immunoblotting analysis showed that MMC reduced TGFBI mRNA levels and cellular and media TGFBIp protein levels in all cell types. MMC induced apoptosis, and the effects of MMC were greatest in GCD II homozygote cells. MMC also reduced the production of TGFBIp in all three types of corneal fibroblasts. These findings may explain the additional therapeutic effect of MMC in GCD II patients.

Anti-cancer Activity of Novel TM4SF5-Targeting Antibodies through TM4SF5 Neutralization and Immune Cell-Mediated Cytotoxicity

PubMed Central

Ahn, Hye-Mi; Ryu, Jihye; Song, Jin Myeong; Lee, Yunhee; Kim, Hye-Jin; Ko, Dongjoon; Choi, Inpyo; Kim, Sang Jick; Lee, Jung Weon; Kim, Semi

2017-01-01

The transmembrane four L6 family member 5 (TM4SF5) protein is a novel molecular target for the prevention and treatment of hepatocellular carcinoma. TM4SF5 is highly expressed in liver, colon, esophageal, and pancreatic cancers and is implicated in tumor progression. Here, we screened monoclonal antibodies that specifically bound to the extracellular loop 2 (EC2) of TM4SF5 from a phage-displayed murine antibody (single-chain variable fragment; scFv) library. We constructed and characterized chimeric antibodies, Ab27 and Ab79, of scFv fused with Fc domain of human IgG1. The affinity (KD) of Ab27 and Ab79 for soluble EC2 was approximately 9.2 nM and 16.9 nM, respectively, as determined by surface plasmon resonance analysis. Ab27 and Ab79 efficiently bound to native TM4SF5 on the cell surface were internalized into the cancer cells, leading to a decrease in cell surface TM4SF5. Ab27 and Ab79 inhibited the proliferation and invasion of TM4SF5-positive liver and colon cancer cells and reduced FAK and c-Src phosphorylation. Ab27 and Ab79 also enhanced anoikis sensitivity and reduced survivin. Ab27 mediated antibody-dependent cell-mediated cytotoxicity in vitro. Ab27 and Ab79 efficiently inhibited tumor growth in a liver cancer xenograft model. These results strongly support the further development of Ab27 as a novel anti-cancer agent in the clinic. PMID:28255353

Gallium Arsenide solar cell radiation damage experiment

NASA Technical Reports Server (NTRS)

Maurer, R. H.; Kinnison, J. D.; Herbert, G. A.; Meulenberg, A.

1991-01-01

Gallium arsenide (GaAs) solar cells for space applications from three different manufactures were irradiated with 10 MeV protons or 1 MeV electrons. The electrical performance of the cells was measured at several fluence levels and compared. Silicon cells were included for reference and comparison. All the GaAs cell types performed similarly throughout the testing and showed a 36 to 56 percent power areal density advantage over the silicon cells. Thinner (8-mil versus 12-mil) GaAs cells provide a significant weight reduction. The use of germanium (Ge) substrates to improve mechanical integrity can be implemented with little impact on end of life performance in a radiation environment.

Multi-walled carbon nanotubes (NM401) induce ROS-mediated HPRT mutations in Chinese hamster lung fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rubio, Laura; El Yamani, Naouale; Kazimirova, Alena

Although there is an important set of data showing potential genotoxic effects of nanomaterials (NMs) at the DNA (comet assay) and chromosome (micronucleus test) levels, few studies have been conducted to analyze their potential mutagenic effects at gene level. We have determined the ability of multi-walled carbon nanotubes (MWCNT, NM401), to induce mutations in the HPRT gene in Chinese hamster lung (V79) fibroblasts. NM401, characterized in the EU NanoGenotox project, were further studied within the EU Framework Programme Seven (FP7) project NANoREG. From the proliferation assay data we selected a dose-range of 0.12 to 12 µg/cm{sup 2} At these rangemore » we have been able to observe significant cellular uptake of MWCNT by using transmission electron microscopy (TEM), as well as a concentration-dependent induction of intracellular reactive oxygen species. In addition, a clear concentration-dependent increase in the induction of HPRT mutations was also observed. Data support a potential genotoxic/ carcinogenic risk associated with MWCNT exposure. - Highlights: • MWCNT were tested in V79 cells. • Cellular uptake of MWCNT was detected using TEM. • Intracellular ROS induction was observed after MWCNT exposure. • MWCNT induced a concentration-dependent increase of HPRT mutations.« less

Immunohistochemical expression of E-cadherin does not distinguish canine cutaneous histiocytoma from other canine round cell tumors.

PubMed

Ramos-Vara, J A; Miller, M A

2011-05-01

Immunohistochemistry for E-cadherin (ECAD) has been used to distinguish canine cutaneous histiocytoma from other leukocytic neoplasms ("round cell tumors"). To determine the specificity of this test, 5 types of canine cutaneous round cell tumors were evaluated for immunohistochemical expression of ECAD. Tumors of all 5 types had variable cytoplasmic, plasma membrane, and/or paranuclear ECAD expression: All 13 cutaneous histiocytomas were ECAD+; all but 1 of 14 mast cell tumors expressed ECAD; 10 of 12 epitheliotropic lymphomas reacted with E-cadherin antibody; of 72 plasmacytomas, 54 were ECAD+; and 5 of 5 histiocytic sarcomas were positive. Conclusions based on these results include the following: First, immunoreactivity for ECAD is not limited to leukocytes of cutaneous histiocytoma; second, antibody to ECAD also labels neoplastic cells in most mast cell tumors, plasmacytomas, cutaneous histiocytic sarcomas, and epitheliotropic lymphomas; third, although most histiocytomas have membranous ECAD expression, the immunoreactivity varies among round cell tumors and is frequently concurrent in different cellular compartments; fourth, the distinctively paranuclear ECAD expression pattern in epitheliotropic lymphomas might distinguish them from other round cell tumors; and, fifth, ECAD should be used with other markers (eg, MUM1 for plasmacytomas, KIT for mast cell tumors, CD3 and CD79a for lymphomas) to distinguish among canine round cell tumors.

Cytokine profiles of HeLa and human diploid cells induced by different fractions of Vibrio parahaemolyticus cultures exposed to stress conditions.

PubMed

Chifiriuc, Mariana Carmen; Bleotu, Coralia; Pîrcălăbioru, Gratiela; Israil, Anca Michaela; Dinu, Sorin; Rută, Simona Maria; Grancea, Camelia; Lazăr, Veronica

2010-01-01

Vibrio (V.) parahaemolyticus is an aquatic halophilic bacteria which produces gastroenteritis and in rare cases septicaemia after the consumption of raw or under-cooked contaminated seafood.The severity of diarrheal illness caused by this bacterium is closely related to the presence of two types of hemolysins (the thermostable direct hemolysin-TDH and TDH related hemolysin-TRH) and also of type III secretion system (TTSS) proteins. The TTSS type 1 induces a wide array of effects on infected HeLa cells such as autophagy, oncosis, cell rounding and lysis. Previous studies have shown that heat shock proteins have the ability to stimulate the production of interleukins in different cellular cultures. In our studies we have stimulated two cellular lines (HeLa and human diploid cells) with different V. parahaemolyticus culture fractions in order to observe the effect on cytokines production. Thus, the purpose of this study was to analyze the expression of IL-1, IL-2, IL-4, IL-6, IL-10 and TNF-alpha induced by the cell treatment with total cellular lysate, periplasmic fractions and culture supernatants extracted from V. parahaemolyticus exposed to normal and also to stress conditions. The ELISA assay of the cytokine profile of the HeLa and HDC cell lines stimulated with different bacterial fractions revealed that in the V. parahemolyticus cultures submitted to osmotic and heat shock stress are accumulating factors (probably heat shock proteins) which are exhibiting immunomodulatory activity, responsible for the induction of a pro-inflammatory response associated with increased levels of IL-6 and TNF-alpha expression, however balanced by the stimulation of the anti-inflammatory cytokine IL-4 synthesis.

Binding-, intracellular transport-, and biosynthesis-defective mutants of vasopressin type 2 receptor in patients with X-linked nephrogenic diabetes insipidus.

PubMed Central

Tsukaguchi, H; Matsubara, H; Taketani, S; Mori, Y; Seido, T; Inada, M

1995-01-01

Nephrogenic diabetes insipidus (NDI) is most often an X-linked disorder in which urine is not concentrated due to renal resistance to arginine vasopressin. We recently identified four vasopressin type 2 receptor gene mutations in unrelated X-linked NDI families, including R143P, delta V278, R202C, and 804insG. All these mutations reduced ligand binding activity to < 10% of the normal without affecting mRNA accumulation. To elucidate whether the receptors are expressed on the cell surface, we analyzed biosynthesis and localization of tagged or untagged receptors stably expressed in Chinese hamster ovary (CHO) cells, using two antibodies directed against distinct termini. Whole-cell and surface labeling studies revealed that the R202C clone had both surface-localized (50-55 kD) and intracellular proteins (40 and 75 kD), similar to the wild-type AVPR2 clone, whereas the R143P and delta V278 clones lacked the surface receptors, despite relatively increased intracellular components. The 804insG mutant cell produced no proteins despite an adequate mRNA level. Immunofluorescence staining confirmed that the R202C mutant reaches the cell surface, whereas the R143P and delta V278 mutants are retained within the cytoplasmic compartment. Thus, R202C, R143P/delta V278, and 804insG result in three distinct phenotypes, that is, a simple binding impairment at the cell surface, blocked intracellular transport, and ineffective biosynthesis or/and accelerated degradation of the receptor, respectively, and therefore are responsible for NDI. This phenotypic classification will help understanding of molecular pathophysiology of this disorder. Images PMID:7560098

Altered Agonist Sensitivity of a Mutant V2 Receptor Suggests a Novel Therapeutic Strategy for Nephrogenic Diabetes Insipidus

PubMed Central

Erdélyi, László Sándor; Balla, András; Patócs, Attila; Tóth, Miklós; Várnai, Péter

2014-01-01

Loss-of-function mutations of the type 2 vasopressin receptor (V2R) in kidney can lead to nephrogenic diabetes insipidus (NDI). We studied a previously described, but uncharacterized, mutation of the V2R (N321K missense mutation) of a patient with NDI. The properties of the mutant receptor were evaluated. We constructed a highly sensitive Epac-based bioluminescence resonance energy transfer biosensor to perform real-time cAMP measurements after agonist stimulation of transiently transfected HEK293 cells with V2Rs. β-Arrestin binding of the activated receptors was examined with luciferase-tagged β-arrestin and mVenus-tagged V2Rs using the bioluminescence resonance energy transfer technique. Cell surface expression levels of hemagglutinin-tagged receptors were determined with flow cytometry using anti-hemagglutinin-Alexa 488 antibodies. Cellular localization examinations were implemented with fluorescent tagged receptors visualized with confocal laser scanning microscopy. The effect of various vasopressin analogs on the type 1 vasopressin receptor (V1R) was tested on mouse arteries by wire myography. The N321K mutant V2R showed normal cell surface expression, but the potency of arginine vasopressin for cAMP generation was low, whereas the clinically used desmopressin was not efficient. The β-arrestin binding and internalization properties of the mutant receptor were also different than those for the wild type. The function of the mutant receptor can be rescued with administration of the V2R agonist Val4-desmopressin, which had no detectable side effects on V1R in the effective cAMP generating concentrations. Based on these findings we propose a therapeutic strategy for patients with NDI carrying the N321K mutation, as our in vivo experiments suggest that Val4-desmopressin could rescue the function of the N321K-V2R without significant side effects on the V1R. PMID:24628417

Altered agonist sensitivity of a mutant v2 receptor suggests a novel therapeutic strategy for nephrogenic diabetes insipidus.

PubMed

Erdélyi, László Sándor; Balla, András; Patócs, Attila; Tóth, Miklós; Várnai, Péter; Hunyady, László

2014-05-01

Loss-of-function mutations of the type 2 vasopressin receptor (V2R) in kidney can lead to nephrogenic diabetes insipidus (NDI). We studied a previously described, but uncharacterized, mutation of the V2R (N321K missense mutation) of a patient with NDI. The properties of the mutant receptor were evaluated. We constructed a highly sensitive Epac-based bioluminescence resonance energy transfer biosensor to perform real-time cAMP measurements after agonist stimulation of transiently transfected HEK293 cells with V2Rs. β-Arrestin binding of the activated receptors was examined with luciferase-tagged β-arrestin and mVenus-tagged V2Rs using the bioluminescence resonance energy transfer technique. Cell surface expression levels of hemagglutinin-tagged receptors were determined with flow cytometry using anti-hemagglutinin-Alexa 488 antibodies. Cellular localization examinations were implemented with fluorescent tagged receptors visualized with confocal laser scanning microscopy. The effect of various vasopressin analogs on the type 1 vasopressin receptor (V1R) was tested on mouse arteries by wire myography. The N321K mutant V2R showed normal cell surface expression, but the potency of arginine vasopressin for cAMP generation was low, whereas the clinically used desmopressin was not efficient. The β-arrestin binding and internalization properties of the mutant receptor were also different than those for the wild type. The function of the mutant receptor can be rescued with administration of the V2R agonist Val(4)-desmopressin, which had no detectable side effects on V1R in the effective cAMP generating concentrations. Based on these findings we propose a therapeutic strategy for patients with NDI carrying the N321K mutation, as our in vivo experiments suggest that Val(4)-desmopressin could rescue the function of the N321K-V2R without significant side effects on the V1R.

Modulation of voltage- and Ca2+-dependent gating of CaV1.3 L-type calcium channels by alternative splicing of a C-terminal regulatory domain.

PubMed

Singh, Anamika; Gebhart, Mathias; Fritsch, Reinhard; Sinnegger-Brauns, Martina J; Poggiani, Chiara; Hoda, Jean-Charles; Engel, Jutta; Romanin, Christoph; Striessnig, Jörg; Koschak, Alexandra

2008-07-25

Low voltage activation of Ca(V)1.3 L-type Ca(2+) channels controls excitability in sensory cells and central neurons as well as sinoatrial node pacemaking. Ca(V)1.3-mediated pacemaking determines neuronal vulnerability of dopaminergic striatal neurons affected in Parkinson disease. We have previously found that in Ca(V)1.4 L-type Ca(2+) channels, activation, voltage, and calcium-dependent inactivation are controlled by an intrinsic distal C-terminal modulator. Because alternative splicing in the Ca(V)1.3 alpha1 subunit C terminus gives rise to a long (Ca(V)1.3(42)) and a short form (Ca(V)1.3(42A)), we investigated if a C-terminal modulatory mechanism also controls Ca(V)1.3 gating. The biophysical properties of both splice variants were compared after heterologous expression together with beta3 and alpha2delta1 subunits in HEK-293 cells. Activation of calcium current through Ca(V)1.3(42A) channels was more pronounced at negative voltages, and inactivation was faster because of enhanced calcium-dependent inactivation. By investigating several Ca(V)1.3 channel truncations, we restricted the modulator activity to the last 116 amino acids of the C terminus. The resulting Ca(V)1.3(DeltaC116) channels showed gating properties similar to Ca(V)1.3(42A) that were reverted by co-expression of the corresponding C-terminal peptide C(116). Fluorescence resonance energy transfer experiments confirmed an intramolecular protein interaction in the C terminus of Ca(V)1.3 channels that also modulates calmodulin binding. These experiments revealed a novel mechanism of channel modulation enabling cells to tightly control Ca(V)1.3 channel activity by alternative splicing. The absence of the C-terminal modulator in short splice forms facilitates Ca(V)1.3 channel activation at lower voltages expected to favor Ca(V)1.3 activity at threshold voltages as required for modulation of neuronal firing behavior and sinoatrial node pacemaking.

Exogenous ACE2 Expression Allows Refractory Cell Lines To Support Severe Acute Respiratory Syndrome Coronavirus Replication

PubMed Central

Mossel, Eric C.; Huang, Cheng; Narayanan, Krishna; Makino, Shinji; Tesh, Robert B.; Peters, C. J.

2005-01-01

Of 30 cell lines and primary cells examined, productive severe acute respiratory syndrome coronavirus (Urbani strain) (SARS-CoV) infection after low-multiplicity inoculation was detected in only six: three African green monkey kidney epithelial cell lines (Vero, Vero E6, and MA104), a human colon epithelial line (CaCo-2), a porcine kidney epithelial line [PK(15)], and mink lung epithelial cells (Mv 1 Lu). SARS-CoV produced a lytic infection in Vero, Vero E6, and MA104 cells, but there was no visible cytopathic effect in Caco-2, Mv 1 Lu, or PK(15) cells. Multistep growth kinetics were identical in Vero E6 and MA104 cells, with maximum titer reached 24 h postinoculation (hpi). Virus titer was maximal 96 hpi in CaCo-2 cells, and virus was continually produced from infected CaCo-2 cells for at least 6 weeks after infection. CaCo-2 was the only human cell type of 13 tested that supported efficient SARS-CoV replication. Expression of the SARS-CoV receptor, angiotensin-converting enzyme 2 (ACE2), resulted in SARS-CoV replication in all refractory cell lines examined. Titers achieved were variable and dependent upon the method of ACE2 expression. PMID:15731278

¹¹¹In-DOTA-Annexin V for imaging of apoptosis during HSV1-tk/GCV prodrug activation gene therapy in mice with NG4TL4 sarcoma.

PubMed

Lin, Ming-Hsien; Wu, Shih-Yen; Wang, Hsin-Ell; Liu, Ren-Shyan; Chen, Jyh-Cheng

2016-02-01

Apoptosis has been suggested as a cytocidal mechanism of the HSV1-tk-expressing cells when exposed to ganciclovir (GCV). This study evaluated the efficacy of (111)In-labeled Annexin V for monitoring tumor responses during prodrug activation gene therapy with HSV1-tk and GCV. Annexin V was conjugated to DOTA using N-hydroxysulfosuccinimide (sulfo-NHS) and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC), labeled with (111)In-InCl3 and purified using size exclusion chromatography to give (111)In-DOTA-Annexin V conjugate. The radiochemical yield and the radiochemical purity of (111)In-DOTA-Annexin V were 74±12% and 98±3%, respectively (n=10). (111)In-DOTA-BSA was prepared similarly. An in vitro study to demonstrate the apoptosis of NG4TL4-STK cells after GCV treatment has been performed. Mice bearing NG4TL4-STK and NG4TL4-WT tumors were treated with GCV (10 mg/kg daily) by i.p. injection for 7 consecutive days. Before and during the GCV treatment, biodistribution studies and scintigraphic imaging were performed at 2h post injection of the radiotracers. The uptake of (111)In-DOTA-Annexin V in treated cells (13.41±1.30%) was 4.1 times higher than that in untreated cells (3.21±0.37%). The GCV-induced cell apoptosis in NG4TL4-STK tumor resulted in a significantly increasing accumulation of (111)In-DOTA-Annexin V (1.92±0.32%ID/g at day 0, 4.79±0.86%ID/g at day 2, 4.56±0.58%ID/g at day 4) was observed, but not for that of (111)In-DOTA-BSA. During consecutive GCV treatment, scintigraphic imaging with (111)In-DOTA-Annexin V revealed high uptake in NG4TL4-STK tumor compared with that in NG4TL4-WT tumor. However, no specific (111)In-DOTA-BSA accumulation in NG4TL4-STK and NG4TL4-WT tumors was observed throughout the course of GCV treatment. This study demonstrated that (111)In-DOTA-Annexin V can be used for monitoring tumor cell apoptosis during prodrug activation gene therapy with HSV1-tk and GCV for cancer treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Room Temperature Curing Resin Systems for Graphite/Epoxy Composite Repair.

DTIC Science & Technology

1979-12-01

ROOM TEMPERATURE CURING RESIN SYSTEMS FOR GRAPHITE/EPOXY COMPOS--ETC(UI DEC 79 0 J CRABTREE N62269-79-C-G224 UNCLASSIFIE O80-46 NADC -781 1-6 NL END...Room Temperature Curing Resin Sys-U3 linal for Graphite/Epoxy Composite Repair •.Dec *79 NOR- -46h: V111IT NUM8ER(s) 4362269-79- ,722 S. PERFORMING...repair, composite repair room temperature cure resin , moderate temperature cure resins , epoxies, adhesives, vinyl eater polymers, anaerobic curing polymers

Multimap formation in visual cortex

PubMed Central

Jain, Rishabh; Millin, Rachel; Mel, Bartlett W.

2015-01-01

An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps—hereafter a “multimap”—is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated “learning eligibility regions” (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with “salt-and-pepper” structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space. PMID:26641946

Cell-surface properties of Vibrio ordalii strains isolated from Atlantic salmon Salmo salar in Chilean farms.

PubMed

Ruiz, P; Poblete, M; Yáñez, A J; Irgang, R; Toranzo, A E; Avendaño-Herrera, R

2015-02-10

Vibrio ordalii is the causative agent of atypical vibriosis and has the potential to cause severe losses in salmonid aquaculture, but the factors determining its virulence have not yet been elucidated. In this work, cell-surface-related properties of the isolates responsible for outbreaks in Atlantic salmon were investigated. We also briefly examined whether pathogenicity against fish varied for V. ordalii strains with differing cell-surface properties. Hydrocarbon adhesions indicated the hydrophobic character of V. ordalii, although only 4 of 18 isolates induced haemagglutination in Atlantic salmon erythrocytes. A minority of the studied isolates (6 of 18) and the type strain ATCC 33509T produced low-grade biofilm formation on polyethylene surface after 2 h post-inoculation (hpi), but no strains were slime producers. Interestingly, V. ordalii isolates showed wide differences in hydrophobicity. Therefore, we chose 3 V. ordalii isolates (Vo-LM-03, Vo-LM-18 and Vo-LM-16) as representative of each hydrophobicity group (strongly hydrophobic, relatively hydrophobic and quasi-hydrophilic, respectively) and ATCC 33509T was used in the pathogenicity studies. All tested V. ordalii strains except the type strain resisted the killing activity of Atlantic salmon mucus and serum, and could proliferate in these components. Moreover, all V. ordalii isolates adhered to SHK-1 cells, causing damage to fish cell membrane permeability after 16 hpi. Virulence testing using rainbow trout revealed that isolate Vo-LM-18 was more virulent than isolates Vo-LM-03 and Vo-LM-16, indicating some relationship between haemagglutination and virulence, but not with hydrophobicity.

Overexpression of ATP-Binding Cassette Transporter ABCG2 as a Potential Mechanism of Acquired Resistance to Vemurafenib in BRAF(V600E) Mutant Cancer Cells

PubMed Central

Wu, Chung-Pu; Sim, Hong-May; Huang, Yang-Hui; Liu, Yen-Chen; Hsiao, Sung-Han; Cheng, Hsing-Wen; Li, Yan-Qing; Ambudkar, Suresh V.; Hsu, Sheng-Chieh

2012-01-01

Melanoma is the most serious type of skin cancer with a high potential for metastasis and very low survival rates. The discovery of constitutive activation of the BRAF kinase caused by activating BRAF(V600E) kinase mutation in most melanoma patients led to the discovery of the first potent BRAF(V600E) signaling inhibitor, vemurafenib. Vemurafenib was effective in treating advanced melanoma patients and was proposed for the treatment of other BRAF(V600E) mutant cancers as well. Unfortunately, the success of vemurafenib was hampered by the rapid development of acquired resistance in different types of BRAF(V600E) mutant cancer cells. It becomes important to identify and evaluate all of the potential mechanisms of cellular resistance to vemurafenib. In this study, we characterized the interactions of vemurafenib with three major ATP-binding cassette (ABC) transporters, ABCB1, ABCC1 and ABCG2. We found that vemurafenib stimulated the ATPase activity and potently inhibited drug efflux mediated by ABCB1 and ABCG2. Vemurafenib also restored drug sensitivity in ABCG2-overexpressing cells. Moreover, we revealed that in the presence of functional ABCG2, BRAF kinase inhibition by vemurafenib is reduced in BRAF(V600E) mutant A375 cells. Taken together, our findings indicate that ABCG2 confers resistance to vemurafenib in A375 cells, suggesting involvement of this transporter in acquired resistance to vemurafenib. Thus, combination chemotherapy targeting multiple pathways could be an effective therapeutic strategy to overcome acquired resistance to vemurafenib for cancers harboring the BRAF(V600E) mutation. PMID:23153455

The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

NASA Astrophysics Data System (ADS)

Mierke, Claudia Tanja

2013-01-01

The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3high or αvβ3low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3high cells showed a threefold increased cell invasion compared to αvβ3low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3high cells but not in αvβ3low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3high cells, whereas the invasiveness of β3 specific knock-down cells and αvβ3low cells was not altered. In summary, these results suggest that the αvβ3 integrin enhances cancer cell invasion through increased cellular stiffness and enhanced cytoskeletal remodeling dynamics, which enables the cells to generate and transmit contractile forces to overcome the steric hindrance of 3D ECMs.

Reduction of virion-associated σ1 fibers on oncolytic reovirus variants promotes adaptation toward tumorigenic cells.

PubMed

Mohamed, Adil; Teicher, Carmit; Haefliger, Sarah; Shmulevitz, Maya

2015-04-01

Wild-type mammalian orthoreovirus serotype 3 Dearing (T3wt) is nonpathogenic in humans but preferentially infects and kills cancer cells in culture and demonstrates promising antitumor activity in vivo. Using forward genetics, we previously isolated two variants of reovirus, T3v1 and T3v2, with increased infectivity toward a panel of cancer cell lines and improved in vivo oncolysis in a murine melanoma model relative to that of T3wt. Our current study explored how mutations in T3v1 and T3v2 promote infectivity. Reovirions contain trimers of σ1, the reovirus cell attachment protein, at icosahedral capsid vertices. Quantitative Western blot analysis showed that purified T3v1 and T3v2 virions had ∼ 2- and 4-fold-lower levels of σ1 fiber than did T3wt virions. Importantly, using RNA interference to reduce σ1 levels during T3wt production, we were able to generate wild-type reovirus with reduced levels of σ1 per virion. As σ1 levels were reduced, virion infectivity increased by 2- to 5-fold per cell-bound particle, demonstrating a causal relationship between virion σ1 levels and the infectivity of incoming virions. During infection of tumorigenic L929 cells, T3wt, T3v1, and T3v2 uncoated the outer capsid proteins σ3 and μ1C at similar rates. However, having started with fewer σ1 molecules, a complete loss of σ1 was achieved sooner for T3v1 and T3v2. Distinct from intracellular uncoating, chymotrypsin digestion, as a mimic of natural enteric infection, resulted in more rapid σ3 and μ1C removal, unique disassembly intermediates, and a rapid loss of infectivity for T3v1 and T3v2 compared to T3wt. Optimal infectivity toward natural versus therapeutic niches may therefore require distinct reovirus structures and σ1 levels. Wild-type reovirus is currently in clinical trials as a potential cancer therapy. Our molecular studies on variants of reovirus with enhanced oncolytic activity in vitro and in vivo now show that distinct reovirus structures promote adaptation toward cancer cells and away from conditions that mimic natural routes of infection. Specifically, we found that reovirus particles with fewer molecules of the cell attachment protein σ1 became more infectious toward transformed cells. Reduced σ1 levels conferred a benefit to incoming particles only, resulting in an earlier depletion of σ1 and a higher probability of establishing productive infection. Conversely, reovirus variants with fewer σ1 molecules showed reduced stability and infectivity and distinct disassembly when exposed to conditions that mimic natural intestinal proteolysis. These findings support a model where the mode of infection dictates the precise optimum of reovirus structure and provide a molecular rationale for considering alternative reovirus structures during oncolytic therapy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Separation and Analysis of Adherent and Non-Adherent Cancer Cells Using a Single-Cell Microarray Chip.

PubMed

Yamamura, Shohei; Yamada, Eriko; Kimura, Fukiko; Miyajima, Kumiko; Shigeto, Hajime

2017-10-21

A new single-cell microarray chip was designed and developed to separate and analyze single adherent and non-adherent cancer cells. The single-cell microarray chip is made of polystyrene with over 60,000 microchambers of 10 different size patterns (31-40 µm upper diameter, 11-20 µm lower diameter). A drop of suspension of adherent carcinoma (NCI-H1650) and non-adherent leukocyte (CCRF-CEM) cells was placed onto the chip, and single-cell occupancy of NCI-H1650 and CCRF-CEM was determined to be 79% and 84%, respectively. This was achieved by controlling the chip design and surface treatment. Analysis of protein expression in single NCI-H1650 and CCRF-CEM cells was performed on the single-cell microarray chip by multi-antibody staining. Additionally, with this system, we retrieved positive single cells from the microchambers by a micromanipulator. Thus, this system demonstrates the potential for easy and accurate separation and analysis of various types of single cells.

CD147/EMMPRIN acts as a functional entry receptor for measles virus on epithelial cells.

PubMed

Watanabe, Akira; Yoneda, Misako; Ikeda, Fusako; Terao-Muto, Yuri; Sato, Hiroki; Kai, Chieko

2010-05-01

Measles is a highly contagious human disease caused by measles virus (MeV) and remains the leading cause of death in children, particularly in developing countries. Wild-type MeV preferentially infects lymphocytes by using signaling lymphocytic activation molecule (SLAM), whose expression is restricted to hematopoietic cells, as a receptor. MeV also infects other epithelial and neuronal cells that do not express SLAM and causes pneumonia and diarrhea and, sometimes, serious symptoms such as measles encephalitis and subacute sclerosing panencephalitis. The discrepancy between the tissue tropism of MeV and the distribution of SLAM-positive cells suggests that there are unknown receptors other than SLAM for MeV. Here we identified CD147/EMMPRIN (extracellular matrix metalloproteinase inducer), a transmembrane glycoprotein, which acts as a receptor for MeV on epithelial cells. Furthermore, we found the incorporation of cyclophilin B (CypB), a cellular ligand for CD147, in MeV virions, and showed that inhibition of CypB incorporation significantly attenuated SLAM-independent infection on epithelial cells, while it had no effect on SLAM-dependent infection. To date, MeV infection was considered to be triggered by binding of its hemagglutinin (H) protein and cellular receptors. Our present study, however, indicates that MeV infection also occurs via CD147 and virion-associated CypB, independently of MeV H. Since CD147 is expressed in a variety of cells, including epithelial and neuronal cells, this molecule possibly functions as an entry receptor for MeV in SLAM-negative cells. This is the first report among members of the Mononegavirales that CD147 is used as a virus entry receptor via incorporated CypB in the virions.

Performance and temperature dependencies of proton irradiated n/p and p/n GaAs and n/p silicon cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

n/p homojunction GaAs cells are found to be more radiation resistant than p/n heteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increased temperature dependency of maximum power for the GaAs n/p cells is attributed to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations.

Performance and temperature dependencies of proton irradiated n/p GaAs and n/p silicon cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

The n/p homojunction GaAs cell is found to be more radiation resistant than p/nheteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increase temperature dependency of maximum power for the GaAs n/p cells is attributed largely to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations.

Collagen Scaffolds in Bone Sialoprotein-Mediated Bone Regeneration

PubMed Central

Kruger, Thomas E.; Miller, Andrew H.; Wang, Jinxi

2013-01-01

Decades of research in bioengineering have resulted in the development of many types of 3-dimentional (3D) scaffolds for use as drug delivery systems (DDS) and for tissue regeneration. Scaffolds may be comprised of different natural fibers and synthetic polymers as well as ceramics in order to exert the most beneficial attributes including biocompatibility, biodegradability, structural integrity, cell infiltration and attachment, and neovascularization. Type I collagen scaffolds meet most of these criteria. In addition, type I collagen binds integrins through RGD and non-RGD sites which facilitates cell migration, attachment, and proliferation. Type I collagen scaffolds can be used for bone tissue repair when they are coated with osteogenic proteins such as bone morphogenic protein (BMP) and bone sialoprotein (BSP). BSP, a small integrin-binding ligand N-linked glycoprotein (SIBLING), has osteogenic properties and plays an essential role in bone formation. BSP also mediates mineral deposition, binds type I collagen with high affinity, and binds αvβ 3 and αvβ 5 integrins which mediate cell signaling. This paper reviews the emerging evidence demonstrating the efficacy of BSP-collagen scaffolds in bone regeneration. PMID:23653530

Collagen scaffolds in bone sialoprotein-mediated bone regeneration.

PubMed

Kruger, Thomas E; Miller, Andrew H; Wang, Jinxi

2013-01-01

Decades of research in bioengineering have resulted in the development of many types of 3-dimentional (3D) scaffolds for use as drug delivery systems (DDS) and for tissue regeneration. Scaffolds may be comprised of different natural fibers and synthetic polymers as well as ceramics in order to exert the most beneficial attributes including biocompatibility, biodegradability, structural integrity, cell infiltration and attachment, and neovascularization. Type I collagen scaffolds meet most of these criteria. In addition, type I collagen binds integrins through RGD and non-RGD sites which facilitates cell migration, attachment, and proliferation. Type I collagen scaffolds can be used for bone tissue repair when they are coated with osteogenic proteins such as bone morphogenic protein (BMP) and bone sialoprotein (BSP). BSP, a small integrin-binding ligand N-linked glycoprotein (SIBLING), has osteogenic properties and plays an essential role in bone formation. BSP also mediates mineral deposition, binds type I collagen with high affinity, and binds α v β 3 and α v β 5 integrins which mediate cell signaling. This paper reviews the emerging evidence demonstrating the efficacy of BSP-collagen scaffolds in bone regeneration.

Ligament flow during drop-on-demand inkjet printing of bioink containing living cells

NASA Astrophysics Data System (ADS)

Zhang, Mengyun; Krishnamoorthy, Srikumar; Song, Hongtao; Zhang, Zhengyi; Xu, Changxue

2017-03-01

Organ printing utilizes tissue spheroids or filaments as building blocks to fabricate three-dimensional (3D) functional tissues and organs based on a layer-by-layer manufacturing mechanism. These fabricated tissues and organs are envisioned as alternatives to replace the damaged human tissues and organs, which is emerging as a promising solution to solve the organ donor shortage problem being faced all over the world. Inkjetting, one of the key technologies in organ printing, has been widely developed because of its moderate fabrication cost, good process controllability, and scale-up potentials. There are several key steps towards inkjet-based organ printing: generation of droplets from bioink, fabrication of 3D cellular structures, and post-printing tissue fusion and maturation. The droplet formation process is the first step, affecting the overall feasibility of the envisioned organ printing technology. This paper focuses on the ligament flow of the droplet formation process during inkjet printing of bioink containing living cells and its corresponding effect on post-printing cell viability and cell distribution. It is found that (1) two types of ligament flow are observed: at 30 V (Type I), the ligament flow has two different directions at the locations near the nozzle orifice and the forming droplet; at 60 V (Type II), the ligament flow directions are the same at both locations; (2) compared to Type II, fewer cells are ejected into the primary droplets in Type I, because some cells move back into the nozzle driven by the ligament flow in the positive z direction; and (3) cell viability in both Type I and Type II is around 90% without a significant difference. The resulting knowledge will benefit precise control of printing dynamics during inkjet printing of viscoelastic bioink for 3D biofabrication applications.

H+ diffusion and electrochemical stability of Li1+x+yAlxTi2-xSiyP3-yO12 glass in aqueous Li/air battery electrolytes

NASA Astrophysics Data System (ADS)

Ding, Fei; Xu, Wu; Shao, Yuyan; Chen, Xilin; Wang, Zhiguo; Gao, Fei; Liu, Xingjiang; Zhang, Ji-Guang

2012-09-01

It is well known that LATP (Li1+x+yAlxTi2-xSiyP3-yO12) glass is a good lithium (Li)-ion conductor. However, the interaction between LATP glass and H+ ions in aqueous electrolytes (including the diffusion and surface adsorption of H+ ions) needs to be well understood before the long-term application of LATP glass in an aqueous electrolyte can be realized. In this work, we investigate H+-ion diffusion in LATP glass and their interactions with the glass surface using both experimental and modeling approaches. Our results indicate that the apparent H+-related current observed in the initial cyclic voltammetry scan should be attributed to the adsorption of H+ ions on the LATP glass rather than the bulk diffusion of H+ ions. Furthermore, density functional theory calculations indicate that the H+-ion diffusion energy barrier (3.21 eV) is much higher than that for Li+ ions (0.79 eV) and Na+ ions (0.79 eV) in a NASICON-type LiTi2(PO4)3 material. As a result, H+-ion conductivity in LATP glass is negligible at room temperature. However, significant surface corrosion was found after the LATP glass in a strong alkaline electrolyte. Therefore, to prevent LATP glass from corrosion, appropriate electrolytes must be developed for long-term operation of LATP in aqueous Li-air batteries.

A Gammaherpesvirus Bcl-2 Ortholog Blocks B Cell Receptor-Mediated Apoptosis and Promotes the Survival of Developing B Cells In Vivo

PubMed Central

Coleman, Carrie B.; McGraw, Jennifer E.; Feldman, Emily R.; Roth, Alexa N.; Keyes, Lisa R.; Grau, Katrina R.; Cochran, Stephanie L.; Waldschmidt, Thomas J.; Liang, Chengyu; Forrest, J. Craig; Tibbetts, Scott A.

2014-01-01

Gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV, HHV-8) establish lifelong latency in their hosts and are associated with the development of several types of malignancies, including a subset of B cell lymphomas. These viruses are thought to co-opt the process of B cell differentiation to latently infect a fraction of circulating memory B cells, resulting in the establishment of a stable latency setpoint. However, little is known about how this infected memory B cell compartment is maintained throughout the life of the host. We have previously demonstrated that immature and transitional B cells are long-term latency reservoirs for murine gammaherpesvirus 68 (MHV68), suggesting that infection of developing B cells contributes to the maintenance of lifelong latency. During hematopoiesis, immature and transitional B cells are subject to B cell receptor (BCR)-mediated negative selection, which results in the clonal deletion of autoreactive B cells. Interestingly, numerous gammaherpesviruses encode homologs of the anti-apoptotic protein Bcl-2, suggesting that virus inhibition of apoptosis could subvert clonal deletion. To test this, we quantified latency establishment in mice inoculated with MHV68 vBcl-2 mutants. vBcl-2 mutant viruses displayed a marked decrease in the frequency of immature and transitional B cells harboring viral genome, but this attenuation could be rescued by increased host Bcl-2 expression. Conversely, vBcl-2 mutant virus latency in early B cells and mature B cells, which are not targets of negative selection, was remarkably similar to wild-type virus. Finally, in vivo depletion of developing B cells during chronic infection resulted in decreased mature B cell latency, demonstrating a key role for developing B cells in the maintenance of lifelong latency. Collectively, these findings support a model in which gammaherpesvirus latency in circulating mature B cells is sustained in part through the recurrent infection and vBcl-2-mediated survival of developing B cells. PMID:24516386

Caffeine-Induced Premature Chromosome Condensation Results in the Apoptosis-Like Programmed Cell Death in Root Meristems of Vicia faba

PubMed Central

Rybaczek, Dorota; Musiałek, Marcelina Weronika; Balcerczyk, Aneta

2015-01-01

We have demonstrated that the activation of apoptosis-like programmed cell death (AL-PCD) was a secondary result of caffeine (CF) induced premature chromosome condensation (PCC) in hydroxyurea-synchronized Vicia faba root meristem cells. Initiation of the apoptotic-like cell degradation pathway seemed to be the result of DNA damage generated by treatment with hydroxyurea (HU) [double-stranded breaks (DSBs) mostly] and co-treatment with HU/CF [single-stranded breaks (SSBs) mainly]. A single chromosome comet assay was successfully used to study different types of DNA damage (neutral variant–DSBs versus alkaline–DSBs or SSBs). The immunocytochemical detection of H2AXS139Ph and PARP-2 were used as markers for DSBs and SSBs, respectively. Acridine orange and ethidium bromide (AO/EB) were applied for quantitative immunofluorescence measurements of dead, dying and living cells. Apoptotic-type DNA fragmentation and positive TUNEL reaction finally proved that CF triggers AL-PCD in stressed V. faba root meristem cells. In addition, the results obtained under transmission electron microscopy (TEM) further revealed apoptotic-like features at the ultrastructural level of PCC-type cells: (i) extensive vacuolization; (ii) abnormal chromatin condensation, its marginalization and concomitant degradation; (iii) formation of autophagy-like vesicles (iv) protoplast shrinkage (v) fragmentation of cell nuclei and (vi) extensive degeneration of the cells. The results obtained have been discussed with respect to the vacuolar/autolytic type of plant-specific AL-PCD. PMID:26545248

Pseudorabies virus glycoprotein gIII is a major target antigen for murine and swine virus-specific cytotoxic T lymphocytes.

PubMed Central

Zuckermann, F A; Zsak, L; Mettenleiter, T C; Ben-Porat, T

1990-01-01

Pseudorabies virus (PrV) is the etiological agent of Aujeszky's disease, a disease that causes heavy economic losses in the swine industry. A rational approach to the generation of an effective vaccine against this virus requires an understanding of the immune response induced by it and of the role of the various viral antigens in inducing such a response. We have constructed mutants of PrV [strain PrV (Ka)] that differ from each other only in expression of the viral nonessential glycoproteins gI, gp63, gX, and gIII (i.e., are otherwise isogenic). These mutants were used to ascertain the importance of each of the nonessential glycoproteins in eliciting a PrV-specific cytotoxic T-lymphocyte (CTL) response in mice and pigs. Immunization of DBA/2 mice and pigs with a thymidine kinase-deficient (TK-) mutant of PrV elicits the formation of cytotoxic cells that specifically lyse syngeneic infected target cells. These PrV-specific cytolytic cells have the phenotype of major histocompatibility complex class I antigen-restricted CTLs. The relative number of CTLs specific for glycoproteins gI, gp63, gX, and gIII induced in mice vaccinated with a TK- mutant of PrV was ascertained by comparing their levels of cytotoxicity against syngeneic cells infected with either wild-type virus or gI-/gp63-, gX-, or gIII- virus deletion mutants. The PrV-specific CLTs were significantly less effective in lysing gIII(-)-infected targets than in lysing gI-/gp63-, gX-, or wild-type-infected targets. The in vitro secondary CTL response of lymphocytes obtained from either mice or pigs 6 or more weeks after immunization with a TK- mutant of PrV was also tested. Lymphocytes obtained from these animals were cultured with different glycoprotein-deficient mutants of PrV, and their cytolytic activities against wild-type-infected targets were ascertained. The importance of each of the nonessential viral glycoproteins in eliciting CTLs was assessed from the effectiveness of each of the virus mutants to stimulate the secondary anti-PrV CTL response. Cultures of both murine or swine lymphocytes that had been stimulated with gIII- virus contained only approximately half as many lytic units as did those stimulated with either wild-type virus, a gX- virus mutant, or a gI-/gp63- virus mutant. Thus, a large proportion of the PrV-specific CTLs that are induced by immunization with PrV of both mice and pigs are directed against gIII. Furthermore, glycoproteins gI, gp63, and gX play at most a minor role in the CTL response of these animals to PrV. PMID:2153244

Characterization of the gastric immune response in cheetahs (Acinonyx jubatus) with Helicobacter-associated gastritis.

PubMed

Terio, K A; Munson, L; Moore, P F

2012-09-01

Captive cheetahs have an unusually severe progressive gastritis that is not present in wild cheetahs infected with the same strains of Helicobacter. This gastritis, when severe, has florid lymphocyte and plasma cell infiltrates in the epithelium and lamina propria with gland destruction, parietal cell loss, and, in some cases, lymphoid follicles. The local gastric immune response was characterized by immunohistochemistry in 21 cheetahs with varying degrees of gastritis. The character of the response was similar among types of gastritis except that cheetahs with severe gastritis had increased numbers (up to 70%) of lamina proprial CD79a+CD21- B cells. CD3+CD4+ T cells were present in the lamina propria, and CD3+CD8α+ T cells were within the glandular epithelium. Lymphoid aggregates had follicular differentiation with a central core of CD79a+/CD45R+ B cells and with an outer zone of CD3+ T cells that expressed both CD4 and CD8 antigens. MHC II antigens were diffusely expressed throughout the glandular and superficial epithelium. No cheetah had evidence of autoantibodies against the gastric mucosa when gastric samples from 30 cheetahs with different degrees of gastritis were incubated with autologous and heterologous serum. These findings indicate that T-cell distribution in cheetahs is qualitatively similar to that in other species infected with Helicobacter but that large numbers of lamina propria activated B cells and plasma cells did distinguish cheetahs with severe gastritis. Further research is needed to determine whether alterations in the Th1:Th2 balance are the cause of this more plasmacytic response in some cheetahs.

Transcription factor Sp1 regulates T-type Ca(2+) channel CaV 3.1 gene expression.

PubMed

González-Ramírez, Ricardo; Martínez-Hernández, Elizabeth; Sandoval, Alejandro; Felix, Ricardo

2014-05-01

Voltage-gated T-type Ca(2+) (CaV 3) channels mediate a number of physiological events in developing and mature cells, and are implicated in neurological and cardiovascular diseases. In mammals, there are three distinct T-channel genes (CACNA1G, CACNA1H, and CACNA1I) encoding proteins (CaV 3.1-CaV 3.3) that differ in their localization as well as in molecular, biophysical, and pharmacological properties. The CACNA1G is a large gene that contains 38 exons and is localized in chromosome 17q22. Only basic characteristics of the CACNA1G gene promoter region have been investigated classifying it as a TATA-less sequence containing several potential transcription factor-binding motifs. Here, we cloned and characterized a proximal promoter region and initiated the analysis of transcription factors that control CaV 3.1 channel expression using the murine Cacna1g gene as a model. We isolated a ∼1.5 kb 5'-upstream region of Cacna1g and verified its transcriptional activity in the mouse neuroblastoma N1E-115 cell line. In silico analysis revealed that this region possesses a TATA-less minimal promoter that includes two potential transcription start sites and four binding sites for the transcription factor Sp1. The ability of one of these sites to interact with the transcription factor was confirmed by electrophoretic mobility shift assays. Consistent with this, Sp1 over-expression enhanced promoter activity while siRNA-mediated Sp1 silencing significantly decreased the level of CaV 3.1 protein and reduced the amplitude of whole-cell T-type Ca(2+) currents expressed in the N1E-115 cells. These results provide new insights into the molecular mechanisms that control CaV 3.1 channel expression. © 2013 Wiley Periodicals, Inc.

The effect of ligand affinity on integrins' lateral diffusion in cultured cells.

PubMed

Mainali, Dipak; Smith, Emily A

2013-04-01

The role of ligand affinity in altering αPS2CβPS integrins' lateral mobility was studied using single particle tracking (SPT) with ligand-functionalized quantum dots (QDs) and fluorescence recovery after photobleaching (FRAP) with fluorescent protein tagged integrins. Integrins are ubiquitous transmembrane proteins that are vital for numerous cellular functions, including bidirectional signaling and cell anchorage. Wild-type and high ligand affinity mutant (αPS2CβPS-V409D) integrins were studied in S2 cells. As measured by SPT, the integrin mobile fraction decreased by 22% and had a 4× slower diffusion coefficient for αPS2CβPS-V409D compared to wild-type integrins. These differences are partially the result of αPS2CβPS-V409D integrins' increased clustering. For the wild-type integrins, the average of all diffusion coefficients measured by SPT was statistically similar to the ensemble FRAP results. A 75% slower average diffusion coefficient was measured by SPT compared to FRAP for αPS2CβPS-V409D integrins, and this may be the result of SPT measuring only ligand-bound integrins, in contrast all ligand-bound and ligand-unbound integrins are averaged in FRAP measurements. Specific binding of the ligand-functionalized QDs was 99% for integrin expressing cells. The results prove that the ligand binding affinity affects the lateral dynamics of a subset of integrins based on the complementary SPT and FRAP data.

Bruton's tyrosine kinase and protein kinase C µ are required for TLR7/9-induced IKKα and IRF-1 activation and interferon-β production in conventional dendritic cells.

PubMed

Li, Yan-Feng; Lee, Koon-Guan; Ou, Xijun; Lam, Kong-Peng

2014-01-01

Stimulation of TLR7/9 by their respective ligands leads to the activation of IκB kinase α (IKKα) and Interferon Regulatory Factor 1 (IRF-1) and results in interferon (IFN)-β production in conventional dendritic cells (cDC). However, which other signaling molecules are involved in IKKα and IRF-1 activation during TLR7/9 signaling pathway are not known. We and others have shown that Bruton's Tyrosine Kinase (BTK) played a part in TLR9-mediated cytokine production in B cells and macrophages. However, it is unclear if BTK participates in TLR7/9-induced IFN-β production in cDC. In this study, we show that BTK is required for IFN-β synthesis in cDC upon TLR7/9 stimulation and that stimulated BTK-deficient cDC are defective in the induction of IKKα/β phosphorylation and IRF-1 activation. In addition, we demonstrate that Protein Kinase C µ (PKCµ) is also required for TLR7/9-induced IRF-1 activation and IFN-β upregulation in cDC and acts downstream of BTK. Taken together, we have uncovered two new molecules, BTK and PKCµ, that are involved in TLR7/9-triggered IFN-β production in cDC.

High and low energy proton radiation damage in p/n InP MOCVD solar cells

NASA Technical Reports Server (NTRS)

Rybicki, George; Weinberg, Irving; Scheiman, Dave; Vargas-Aburto, Carlos

1995-01-01

InP p(+)nn(+) MOCVD solar cells were irradiated with 0.2 MeV and 10 MeV protons to a fluence of 10(exp 13)/sq cm. The degradation of power output, IV behavior, carrier concentration and defect concentration were observed at intermediate points throughout the irradiations. The 0.2 MeV proton irradiated solar cells suffered much greater and more rapid degradation in power output than those irradiated with 10 meV protons. The efficiency losses were accompanied by larger increases in the recombination currents in the 0.2 MeV proton irradiated solar cells. The low energy proton irradiations also had a larger impact on the series resistance of the solar cells. Despite the radiation induced damage, the carrier concentration in the base of the solar cells showed no reduction after 10 MeV or 0.2 MeV proton irradiations and even increased during irradiation with 0.2 MeV protons. In a DLTS study of the irradiated samples, the minority carrier defects H4 and H5 at E(v) + 0.33 and E(v) + 0.52 eV and the majority carrier defects E7 and E10 at E(c)- 0.39 and E(c)-0.74 eV, were observed. The defect introduction rates for the 0.2 MeV proton irradiations were about 20 times higher than for the 10 MeV proton irradiations. The defect E10, observed here after irradiation, has been shown to act as a donor in irradiated n-type InP and may be responsible for obscuring carrier removal. The results of this study are consistent with the much greater damage produced by low energy protons whose limited range causes them to stop in the active region of the solar cell.

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors

DOE PAGES

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii; ...

2018-03-28

The open-circuit voltage (V oc) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. Here in this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our pi-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (ΔE DA), extends electronic delocalization, and hence improves the V oc. More importantly, these devicesmore » showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.« less

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors.

PubMed

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii; Awais, Mohammad A; Zhang, Na; Chen, Wei; Yu, Luping

2018-04-25

The open-circuit voltage ( V oc ) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. In this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our π-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (Δ E DA ), extends electronic delocalization, and hence improves the V oc . More importantly, these devices showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.

Enhancement in Open-Circuit Voltage in Organic Solar Cells by Using Ladder-Type Nonfullerene Acceptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Zhengxu; Zhao, Donglin; Sharapov, Valerii

The open-circuit voltage (V oc) loss has always been a major factor in lowering power conversion efficiencies (PCEs) in bulk heterojunction organic photovoltaic cells (OPVs). A method to improve the V oc is indispensable to achieve high PCEs. Here in this paper, we investigated a series of perylene diimide-based ladder-type molecules as electron acceptors in nonfullerene OPVs. The D-A ladder-type structures described here lock our pi-systems into a planar structure and eliminate bond twisting associated with linear conjugated systems. This enlarges the interface energy gap (ΔE DA), extends electronic delocalization, and hence improves the V oc. More importantly, these devicesmore » showed an increase in V oc without compromising either the J sc or the FF. C5r exhibited a strong intermolecular interaction and a PCE value of 6.1%. Moreover, grazing-incident wide-angle X-ray scattering analysis and atomic force microscopy images suggested that our fused-ring acceptors showed a suitable domain size and uniform blend films, which were not affected by their rigid molecular structures.« less

Mangiferin prevents the growth of gastric carcinoma by blocking the PI3K-Akt signalling pathway.

PubMed

Du, Min; Wen, Gang; Jin, Juan; Chen, Yuanguang; Cao, Jun; Xu, Aman

2017-12-05

The aim of the present study was to investigate the effects of mangiferin on gastric carcinoma cells and to determine the possible mechanisms underlying such effects. The MTT assay was performed to evaluate the antiproliferative effect of mangiferin. Following treatment, apoptosis rates of SGC-7901 were established by flow cytometry and laser confocal microscopy, and western blot analysis was used to detect the expression of apoptosis-related proteins. The MTT assay showed that mangiferin inhibited the proliferation of SGC-7901 and BCG-823 cells in a dose-dependent and time-dependent manner. After SGC-7901 cells were exposed to mangiferin for 24, 48 and 72 h, the half-maximal inhibitory concentration values were 16.00, 8.63 and 4.79 µmol/l, respectively. SGC-7901 cell apoptosis induced by mangiferin was observed by Annexin V/PI doubling staining and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive staining. We found a significant decrease in Bcl-2, Bcl-xL and Mcl-1 expression and a significant increase in Bax, Bad and cleaved caspase-3 and caspase-9 expression in SGC-7901 cells by mangiferin treatment. Moreover, mangiferin significantly decreased the levels of p-PI3K, p-Akt and p-mTOR, but had no effects on those of PI3K, Akt and mTOR in epidermal growth factor-treated SGC-7901 cells. Interestingly, the proapoptotic effect of mangiferin on SGC-7901 cells was partially blocked by the Akt activator SC79, whereas LY294002 significantly increased mangiferin-induced apoptosis and growth inhibition. Taken together, our findings indicate that mangiferin effectively inhibits cell growth and induces apoptosis of gastric cancer cells through inhibiting the PI3K/Akt pathways with relative safety, and may be used as a novel chemotherapeutic agent against gastric cancer.

X-ray-induced bystander responses reduce spontaneous mutations in V79 cells

PubMed Central

Maeda, Munetoshi; Kobayashi, Katsumi; Matsumoto, Hideki; Usami, Noriko; Tomita, Masanori

2013-01-01

The potential for carcinogenic risks is increased by radiation-induced bystander responses; these responses are the biological effects in unirradiated cells that receive signals from the neighboring irradiated cells. Bystander responses have attracted attention in modern radiobiology because they are characterized by non-linear responses to low-dose radiation. We used a synchrotron X-ray microbeam irradiation system developed at the Photon Factory, High Energy Accelerator Research Organization, KEK, and showed that nitric oxide (NO)-mediated bystander cell death increased biphasically in a dose-dependent manner. Here, we irradiated five cell nuclei using 10 × 10 µm2 5.35 keV X-ray beams and then measured the mutation frequency at the hypoxanthine-guanosine phosphoribosyl transferase (HPRT) locus in bystander cells. The mutation frequency with the null radiation dose was 2.6 × 10–5 (background level), and the frequency decreased to 5.3 × 10–6 with a dose of approximately 1 Gy (absorbed dose in the nucleus of irradiated cells). At high doses, the mutation frequency returned to the background level. A similar biphasic dose-response effect was observed for bystander cell death. Furthermore, we found that incubation with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a specific scavenger of NO, suppressed not only the biphasic increase in bystander cell death but also the biphasic reduction in mutation frequency of bystander cells. These results indicate that the increase in bystander cell death involves mechanisms that suppress mutagenesis. This study has thus shown that radiation-induced bystander responses could affect processes that protect the cell against naturally occurring alterations such as mutations. PMID:23660275

An eight-year epidemiologic study based on baculovirus-expressed type-specific spike proteins for the differentiation of type I and II feline coronavirus infections

PubMed Central

2014-01-01

Background Feline infectious peritonitis (FIP) is a fatal disease caused by feline coronavirus (FCoV). FCoVs are divided into two serotypes with markedly different infection rates among cat populations around the world. A baculovirus-expressed type-specific domain of the spike proteins of FCoV was used to survey the infection of the two viruses over the past eight years in Taiwan. Results An immunofluorescence assay based on cells infected with the recombinant viruses that was capable of distinguishing between the two types of viral infection was established. A total of 833 cases from a teaching hospital was surveyed for prevalence of different FCoV infections. Infection of the type I FCoV was dominant, with a seropositive rate of 70.4%, whereas 3.5% of cats were infected with the type II FCoV. In most cases, results derived from serotyping and genotyping were highly agreeable. However, 16.7% (4/24) FIP cats and 9.8% (6/61) clinically healthy cats were found to possess antibodies against both viruses. Moreover, most of the cats (84.6%, 22/26) infected with a genotypic untypable virus bearing a type I FCoV antibody. Conclusion A relatively simple serotyping method to distinguish between two types of FCoV infection was developed. Based on this method, two types of FCoV infection in Taiwan was first carried out. Type I FCoV was found to be predominant compared with type II virus. Results derived from serotyping and genotyping support our current understanding of evolution of disease-related FCoV and transmission of FIP. PMID:25123112

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petit, Chad M.; Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803; Chouljenko, Vladimir N.

The SARS-coronavirus (SARS-CoV) is the etiological agent of the severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. The cytoplasmic portion of the S glycoprotein contains four cysteine-rich amino acid clusters. Individual cysteine clusters were altered via cysteine-to-alanine amino acid replacement and the modified S glycoproteins were tested for their transport to cell-surfaces and ability to cause cell fusion in transient transfection assays. Mutagenesis of the cysteine cluster I, located immediately proximal to the predicted transmembrane, domain did not appreciably reduce cell-surface expression, although S-mediated cell fusion wasmore » reduced by more than 50% in comparison to the wild-type S. Similarly, mutagenesis of the cysteine cluster II located adjacent to cluster I reduced S-mediated cell fusion by more than 60% compared to the wild-type S, while cell-surface expression was reduced by less than 20%. Mutagenesis of cysteine clusters III and IV did not appreciably affect S cell-surface expression or S-mediated cell fusion. The wild-type S was palmitoylated as evidenced by the efficient incorporation of {sup 3}H-palmitic acid in wild-type S molecules. S glycoprotein palmitoylation was significantly reduced for mutant glycoproteins having cluster I and II cysteine changes, but was largely unaffected for cysteine cluster III and IV mutants. These results show that the S cytoplasmic domain is palmitoylated and that palmitoylation of the membrane proximal cysteine clusters I and II may be important for S-mediated cell fusion.« less

Parainfluenza Virus Infection Sensitizes Cancer Cells to DNA-Damaging Agents: Implications for Oncolytic Virus Therapy.

PubMed

Fox, Candace R; Parks, Griffith D

2018-04-01

A parainfluenza virus 5 (PIV5) with mutations in the P/V gene (P/V-CPI - ) is restricted for spread in normal cells but not in cancer cells in vitro and is effective at reducing tumor burdens in mouse model systems. Here we show that P/V-CPI - infection of HEp-2 human laryngeal cancer cells results in the majority of the cells dying, but unexpectedly, over time, there is an emergence of a population of cells that survive as P/V-CPI - persistently infected (PI) cells. P/V-CPI - PI cells had elevated levels of basal caspase activation, and viability was highly dependent on the activity of cellular inhibitor-of-apoptosis proteins (IAPs) such as Survivin and XIAP. In challenge experiments with external inducers of apoptosis, PI cells were more sensitive to cisplatin-induced DNA damage and cell death. This increased cisplatin sensitivity correlated with defects in DNA damage signaling pathways such as phosphorylation of Chk1 and translocation of damage-specific DNA binding protein 1 (DDB1) to the nucleus. Cisplatin-induced killing of PI cells was sensitive to the inhibition of wild-type (WT) p53-inducible protein 1 (WIP1), a phosphatase which acts to terminate DNA damage signaling pathways. A similar sensitivity to cisplatin was seen with cells during acute infection with P/V-CPI - as well as during acute infections with WT PIV5 and the related virus human parainfluenza virus type 2 (hPIV2). Our results have general implications for the design of safer paramyxovirus-based vectors that cannot establish PI as well as the potential for combining chemotherapy with oncolytic RNA virus vectors. IMPORTANCE There is intense interest in developing oncolytic viral vectors with increased potency against cancer cells, particularly those cancer cells that have gained resistance to chemotherapies. We have found that infection with cytoplasmically replicating parainfluenza virus can result in increases in the killing of cancer cells by agents that induce DNA damage, and this is linked to alterations to DNA damage signaling pathways that balance cell survival versus death. Our results have general implications for the design of safer paramyxovirus-based vectors that cannot establish persistent infection, the repurposing of drugs that target cellular IAPs as antivirals, and the combined use of DNA-damaging chemotherapy agents in conjunction with oncolytic RNA virus vectors. Copyright © 2018 American Society for Microbiology.

Electrochemically Preadsorbed Collagen Promotes Adult Human Mesenchymal Stem Cell Adhesion

PubMed Central

Benavidez, Tomás E.; Wechsler, Marissa E.; Farrer, Madeleine M.; Bizios, Rena

2016-01-01

The present article reports on the effect of electric potential on the adsorption of collagen type I (the most abundant component of the organic phase of bone) onto optically transparent carbon electrodes (OTCE) and its mediation on subsequent adhesion of adult, human, mesenchymal stem cells (hMSCs). For this purpose, adsorption of collagen type I was investigated as a function of the protein concentration (0.01, 0.1, and 0.25 mg/mL) and applied potential (open circuit potential [OCP; control], +400, +800, and +1500 mV). The resulting substrate surfaces were characterized using spectroscopic ellipsometry, atomic force microscopy, and cyclic voltammetry. Adsorption of collagen type I onto OTCE was affected by the potential applied to the sorbent surface and the concentration of protein. The higher the applied potential and protein concentration, the higher the adsorbed amount (Γcollagen). It was also observed that the application of potential values higher than +800 mV resulted in the oxidation of the adsorbed protein. Subsequent adhesion of hMSCs on the OTCEs (precoated with the collagen type I films) under standard cell culture conditions for 2 h was affected by the extent of collagen preadsorbed onto the OTCE substrates. Specifically, enhanced hMSCs adhesion was observed when the Γcollagen was the highest. When the collagen type I was oxidized (under applied potential equal to +1500 mV), however, hMSCs adhesion was decreased. These results provide the first correlation between the effects of electric potential on protein adsorption and subsequent modulation of anchorage-dependent cell adhesion. PMID:26549607

Type-inversion as a working mechanism of high voltage MAPbBr3(Cl)-based halide perovskite solar cells.

PubMed

Kedem, Nir; Kulbak, Michael; Brenner, Thomas M; Hodes, Gary; Cahen, David

2017-02-22

Using several metals with different work functions as solar cell back contact we identify majority carrier type inversion in methylammonium lead bromide (MAPbBr3, without intentional doping) as the basis for the formation of a p-n junction. MAPbBr 3 films deposited on TiO 2 are slightly n-type, whereas in a full device they are strongly p-type. The charge transfer between the metal electrode and the halide perovskite (HaP) film is shown to determine the dominant charge carrier type of the HaP and, thus, also of the final cells. Usage of Pt, Au and Pb as metal electrodes shows the effects of metal work function on minority carrier diffusion length and majority carrier concentration in the HaP, as well as on built-in voltage, band bending, and open circuit voltage (V OC ) within a solar cell. V OC > 1.5 V is demonstrated. The higher the metal WF, the higher the carrier concentration induced in the HaP, as indicated by a narrower space charge region and a smaller minority carrier diffusion length. From the analysis of bias-dependent electron beam-induced currents, the HaP carrier concentrations are estimated to be ∼ 1 × 10 17 cm -3 with Au and 2-3 × 10 18 cm -3 with Pt. A model in which type-inversion stretches across the entire film width implies formation of the p-n junction away from the interface, near the back-contact metal electrode. This work highlights the importance of the contact metal on device performance in that contact engineering can also serve to control the carrier concentration in HaP.

High-efficiency, deep-junction, epitaxial InP solar cells on (100) and (111)B InP substrates

NASA Technical Reports Server (NTRS)

Venkatasubramanian, R.; Timmons, M. L.; Hutchby, J. A.; Walters, Robert J.; Summers, Geoffrey P.

1994-01-01

We report on the development and performance of deep-junction (approximately 0.25 micron), graded-emitter-doped, n(sup +)-p InP solar cells grown by metallorganic chemical vapor deposition (MOCVD). A novel, diffusion-transport process for obtaining lightly-doped p-type base regions of the solar cell is described. The I-V data and external quantum-efficiency response of these cells are presented. The best active-area AMO efficiency for these deep-junction cells on (100)-oriented InP substrates is 16.8 percent, with a J(sub SC) of 31.8 mA/sq cm, a V(sub OC) of 0.843 V, and a fill-factor of 0.85. By comparison, the best cell efficiency on the (111)B-oriented InP substrates was 15.0 percent. These efficiency values for deep-junction cells are encouraging and compare favorably with performance of thin-emitter (0.03 micron) epitaxial cells as well as that of deep-emitter diffused cells. The cell performance and breakdown voltage characteristics of a batch of 20 cells on each of the orientations are presented, indicating the superior breakdown voltage properties and other characteristics of InP cells on the (111)B orientation. Spectral response, dark I-V data, and photoluminescence (PL) measurements on the InP cells are presented with an analysis on the variation in J(sub SC) and V(sub OC) of the cells. It is observed, under open-circuit conditions, that lower-V(sub OC) cells exhibit higher band-edge PL intensity for both the (100) and (111)B orientations. This anomalous behavior suggests that radiative recombination in the heavily-doped n(sup +)-InP emitter may be detrimental to achieving higher V(sub OC) in n(sup +)-p InP solar cells.

Anti‐CD22 and anti‐CD79b antibody‐drug conjugates preferentially target proliferating B cells

PubMed Central

Fuh, Franklin K; Looney, Caroline; Li, Dongwei; Poon, Kirsten A; Dere, Randall C; Danilenko, Dimitry M; McBride, Jacqueline; Reed, Chae; Chung, Shan; Zheng, Bing; Mathews, William Rodney; Polson, Andrew; Williams, Marna

2017-01-01

Background and Purpose CD22 and CD79b are cell‐surface receptors expressed on B‐cell‐derived malignancies such as non‐Hodgkin's lymphoma (NHL). An anti‐mitotic agent, monomethyl auristatin E, was conjugated to anti‐CD22 and anti‐CD79b antibodies to develop target‐specific therapies for NHL. The mechanism of action (MOA) and pharmacological and pharmacokinetic (PK) profiles of these antibody‐drug conjugates (ADCs) were investigated in cynomolgus monkeys. Experimental Approach Animals were administered anti‐CD22 or anti‐CD79b ADCs, respective unconjugated antibodies or vehicle. Pharmacodynamic effects on total and proliferating B cells and serum PK were then assessed. Antibody‐dependent cellular cytotoxicity (ADCC) and complement‐dependent cytotoxicity (CDC) of the ADCs were evaluated in vitro. Key Results Depletion of B cells was observed after administration of either ADC or the respective unconjugated antibodies. An extended duration of depletion was observed in animals administered ADCs. Similarly, preferential depletion of proliferating B cells in blood and germinal centre B cells in spleen were only observed in animals administered ADCs. Serum PK profiles of ADCs and respective unconjugated antibodies were comparable. In vitro, anti‐human CD22 and anti‐human CD79b antibodies showed no or only moderate ADCC activity, respectively; neither antibody had CDC activity. Conclusions and Implications The findings support the proposed MOA: initial depletion of total B cells by antibody‐mediated opsonization, followed by preferential, sustained depletion of proliferating B cells by the auristatin conjugate due to its anti‐mitotic action. Delivering potent anti‐mitotic agents to B cells via the specificity of monoclonal antibodies provides a means to eliminate pathogenic B cells in NHL with improved risk–benefit profiles over traditional chemotherapeutics. PMID:28009435

Collagen V expression is crucial in regional development of the supraspinatus tendon.

PubMed

Connizzo, Brianne K; Adams, Sheila M; Adams, Thomas H; Birk, David E; Soslowsky, Louis J

2016-12-01

Manipulations in cell culture and mouse models have demonstrated that reduction of collagen V results in altered fibril structure and matrix assembly. A tissue-dependent role for collagen V in determining mechanical function was recently established, but its role in determining regional properties has not been addressed. The objective of this study was to define the role(s) of collagen V expression in establishing the site-specific properties of the supraspinatus tendon. The insertion and midsubstance of tendons from wild type, heterozygous and tendon/ligament-specific null mice were assessed for crimp morphology, fibril morphology, cell morphology, as well as total collagen and pyridinoline cross-link (PYD) content. Fibril morphology was altered at the midsubstance of both groups with larger, but fewer, fibrils and no change in cell morphology or collagen compared to the wild type controls. In contrast, a significant disruption of fibril assembly was observed at the insertion site of the null group with the presence of structurally aberrant fibrils. Alterations were also present in cell density and PYD content. Altogether, these results demonstrate that collagen V plays a crucial role in determining region-specific differences in mouse supraspinatus tendon structure. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2154-2161, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Enhanced current collection in 1.7 eV GaInAsP solar cells grown on GaAs by metalorganic vapor phase epitaxy

DOE PAGES

Jain, Nikhil; Geisz, John F.; France, Ryan M.; ...

2017-02-08

Quaternary GaInAsP solar cells with a bandgap of ~1.7 eV offer an attractive Al-free alternative to AlGaAs solar cells for integration in next generation of III-V multijunction solar cells with five or more junctions. Development of a high quality 1.7 eV solar cell is also highly sought for III-V/Si tandem solar cells. In this work, we systematically investigate the impact of varying base thicknesses and doping concentrations on the carrier collection and performance of 1.7 eV GaInAsP solar cells. The photoresponse of these cells is found to be very sensitive to p-type zinc doping concentration in the base layer. Prototypemore » 1.7 eV GaInAsP n-i-p solar cell designs are demonstrated that leverage enhanced depletion width as an effective method to achieve peak quantum efficiency exceeding 90%. We also show the importance of optimal i-layer thickness as a critical parameter to reduce the drop in fill-factor (FF) due to field-aided collection. Furthermore, we demonstrate substantial improvement in the cell performance when the GaInAsP base layer is grown at 650 degrees C instead of 600 degrees C. The best GaInAsP solar cell (Eg ~ 1.65 eV) in this study achieved JSC of 21.1 mA/cm 2, VOC of 1.18 V, FF of 83.8%, and an efficiency of 20.8 +/- 1% under AM1.5D spectrum (21.5 +/- 1% under AM1.5G spectrum). Finally, these results highlight the potential of Al-free GaInAsP solar cells for integration in the next generation of III-V multijunction solar cells.« less

Enhanced current collection in 1.7 eV GaInAsP solar cells grown on GaAs by metalorganic vapor phase epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jain, Nikhil; Geisz, John F.; France, Ryan M.

Quaternary GaInAsP solar cells with a bandgap of ~1.7 eV offer an attractive Al-free alternative to AlGaAs solar cells for integration in next generation of III-V multijunction solar cells with five or more junctions. Development of a high quality 1.7 eV solar cell is also highly sought for III-V/Si tandem solar cells. In this work, we systematically investigate the impact of varying base thicknesses and doping concentrations on the carrier collection and performance of 1.7 eV GaInAsP solar cells. The photoresponse of these cells is found to be very sensitive to p-type zinc doping concentration in the base layer. Prototypemore » 1.7 eV GaInAsP n-i-p solar cell designs are demonstrated that leverage enhanced depletion width as an effective method to achieve peak quantum efficiency exceeding 90%. We also show the importance of optimal i-layer thickness as a critical parameter to reduce the drop in fill-factor (FF) due to field-aided collection. Furthermore, we demonstrate substantial improvement in the cell performance when the GaInAsP base layer is grown at 650 degrees C instead of 600 degrees C. The best GaInAsP solar cell (Eg ~ 1.65 eV) in this study achieved JSC of 21.1 mA/cm 2, VOC of 1.18 V, FF of 83.8%, and an efficiency of 20.8 +/- 1% under AM1.5D spectrum (21.5 +/- 1% under AM1.5G spectrum). Finally, these results highlight the potential of Al-free GaInAsP solar cells for integration in the next generation of III-V multijunction solar cells.« less

Myostatin regulates proliferation and extracellular matrix mRNA expression in NIH3T3 fibroblasts.

PubMed

Z Hosaka, Yoshinao; Ishibashi, Mika; Wakamatsu, Jun-Ichi; Uehara, Masato; Nishimura, Takanori

2012-12-01

The aim of this study was to clarify the effects of myostatin, which is a negative regulator of skeletal muscle mass, on the proliferation of NIH3T3 fibroblasts and the synthesis of extracellular matrix (ECM) by them. A proliferation assay revealed that myostatin attenuated cell growth at any of the doses used. High doses of myostatin strongly inhibited cell proliferation. Moreover, myostatin receptor, activin receptor type-2B (ActRIIB), was found to be distributed on cells and it was also clarified that myostatin increased the expression of cyclin-dependent kinase inhibitor p21 (p21). These results suggested that a high dose of myostatin inhibits fibroblast proliferation by the same mechanism as that for inhibition of myoblast proliferation. We then examined the effects of myostatin on the mRNA expression of ECM molecules (decorin, biglycan, type I collagen, type III collagen, type IV collagen and type V collagen) by real-time PCR. Real-time PCR showed that myostatin increased the mRNA of decorin, biglycan and collagen (types I, IV and V) in fibroblasts. The results suggest that myostatin regulates ECM synthesis in cultured fibroblasts.

Histopathological investigation in porcine infected with torque teno sus virus type 2 by inoculation

PubMed Central

2011-01-01

Background Porcine torque teno sus virus (TTSuV) is a small icosahedral and non-enveloped virus which contains a single-stranded (ssDNA), circular and negative DNA genome and infects mainly vertebrates and is currently classified into the 'floating' genus Anellovirus of Circoviridae with two species. Viral DNA of both porcine TTSuV species has a high prevalence in both healthy and diseased pigs worldwide and multiple infections of TTSuV with distinct genotypes or subtypes of the same species has been documented in the United States, Europe and Asia. However, there exists no information about histopathological lesions caused by infection with porcine TTSuV2. Methods Porcine liver tissue homogenate with 1 ml of 6.91 × 107genomic copies viral loads of porcine TTSuV2 that had positive result for torque teno sus virus type 2 and negative result for torque teno sus virus type 1 and porcine pseudorabies virus type 2 were used to inoculate specific pathogen-free piglets by intramuscular route and humanely killed at 3,7,10,14,17,21 and 24 days post inoculation (dpi), the control pigs were injected intramuscularly with 1 ml of sterile DMEM and humanely killed the end of the study for histopathological examination routinely processed, respectively. Results All porcine TTSuV2 inoculated piglets were clinic asymptomatic but developed myocardial fibroklasts and endocardium, interstitial pneumonia, membranous glomerular nephropathy, and modest inflammatory cells infiltration in portal areas in the liver, foci of hemorrhage in some pancreas islet, a tiny amount red blood cells in venule of muscularis mucosae and outer longitudinal muscle, rarely red blood cells in the microvasculation and infiltration of inflammatory cells (lymphocytes and eosinophils) of tonsil and hilar lymph nodes, infiltration of inflammatory lymphocytes and necrosis or degeneration and focal gliosis of lymphocytes in the paracortical zone after inoculation with porcine TTSuV2-containing tissue homogenate. Conclusions Analysis of these presentations revealed that porcine TTSuV2 was readily transmitted to TTSuV-negative swine and that infection was associated with characteristic pathologic changes in specific pathogen-free piglets inoculated with porcine TTSuV2. Those results indicated no markedly histopathological changes happened in those parenchymatous organs, especially the digestive system and immune system when the specific pathogen-free pigs were infected with porcine TTSuV2, hence, to some extent, it was not remarkable pathological agent for domestic pigs at least. So, porcine TTSuV2 could be an unrecognized pathogenic viral infectious etiology of swine. This study indicated a directly related description of lesions responsible for TTSuV2 infection in swine. PMID:22171963

Asperosaponin VI promotes progesterone receptor expression in decidual cells via the notch signaling pathway.

PubMed

Gao, Jie; Zhou, Chun; Li, Yadi; Gao, Feixia; Wu, Haiwang; Yang, Lilin; Qiu, Weiyu; Zhu, Lin; Du, Xin; Lin, Weixian; Huang, Dandan; Liu, Haibin; Liang, Chun; Luo, Songping

2016-09-01

Recurrent spontaneous abortion (RSA) is a common clinical condition, but its reasons remain unknown in 37-79% of the affected women. The steroid hormone progesterone (P4) is an integral mediator of early pregnancy events, exerting its effects via the progesterone receptor (PR). Dipsaci Radix (DR) has long been used for treating gynecological diseases in Chinese medicine, while its molecular mechanisms and active ingredients are still unclear. We report here the progesterone-like effects of the alcohol extraction and Asperosaponin VI from DR in primary decidual cells and HeLa cell line. We first determined the safe concentration of Asperosaponin VI in the cells with MTT assay and then found by using dual luciferase reporter and Western blotting that Asperosaponin VI significantly increased PR expression. Moreover, we explored the mechanisms of action of the DR extracts and Asperosaponin VI, and the results showed that they could activate Notch signaling, suggesting that they may function by promoting decidualization. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

Proteomic Investigation to Identify Anticancer Targets of Nemopilema nomurai Jellyfish Venom in Human Hepatocarcinoma HepG2 Cells

PubMed Central

Choudhary, Indu; Lee, Hyunkyoung; Pyo, Min Jung; Heo, Yunwi; Chae, Jinho; Yum, Seung Shic; Kang, Changkeun; Kim, Euikyung

2018-01-01

Nemopilema nomurai is a giant jellyfish that blooms in East Asian seas. Recently, N. nomurai venom (NnV) was characterized from a toxicological and pharmacological point of view. A mild dose of NnV inhibits the growth of various kinds of cancer cells, mainly hepatic cancer cells. The present study aims to identify the potential therapeutic targets and mechanism of NnV in the growth inhibition of cancer cells. Human hepatocellular carcinoma (HepG2) cells were treated with NnV, and its proteome was analyzed using two-dimensional gel electrophoresis, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF/MS). The quantity of twenty four proteins in NnV-treated HepG2 cells varied compared to non-treated control cells. Among them, the amounts of fourteen proteins decreased and ten proteins showed elevated levels. We also found that the amounts of several cancer biomarkers and oncoproteins, which usually increase in various types of cancer cells, decreased after NnV treatment. The representative proteins included proliferating cell nuclear antigen (PCNA), glucose-regulated protein 78 (GRP78), glucose-6-phosphate dehydrogenase (G6PD), elongation factor 1γ (EF1γ), nucleolar and spindle-associated protein (NuSAP), and activator of 90 kDa heat shock protein ATPase homolog 1 (AHSA1). Western blotting also confirmed altered levels of PCNA, GRP78, and G6PD in NnV-treated HepG2 cells. In summary, the proteomic approach explains the mode of action of NnV as an anticancer agent. Further characterization of NnV may help to unveil novel therapeutic agents in cancer treatment. PMID:29748501

c-erbA and v-erbA modulate growth and gene expression of a mouse glial precursor cell line.

PubMed

Iglesias, T; Llanos, S; López-Barahona, M; Pérez-Aranda, A; Rodríguez-Peña, A; Bernal, J; Höhne, A; Seliger, B; Muñoz, A

1994-07-01

The c-erbA alpha protooncogene coding for the thyroid hormone (T3) receptor (TR alpha 1) and the viral, mutated v-erbA oncogene were expressed in an immortal mouse glial cell line (B3.1) using retroviral vectors. c-erbA alpha expression led to a decrease in cell proliferation in high and low serum conditions, both in the presence and in the absence of T3. In serum-free medium, c-erbA-expressing cells (B3.1 + TR alpha 1) were completely arrested, whereas cells expressing v-erbA (B3.1 + v-erbA) showed a higher DNA synthesis rate than normal B3.1 cells. Although proliferation of all three cell types was stimulated by platelet-derived growth factor and basic fibroblast growth factor, differences were also observed in the response to these agents. B3.1 + TR alpha 1 cells were more sensitive to platelet-derived growth factor than B3.1 and B3.1 + v-erbA cells. In contrast, B3.1 cells responded to basic fibroblast growth factor better than B3.1 + TR alpha 1 or B3.1 + v-erbA cells. Insulin-like growth factor I potentiated the action of platelet-derived growth factor and basic fibroblast growth factor. Again, different responses to treatment with insulin-like growth factor I alone were observed; B3.1 + TR alpha 1 cells did not respond to it, whereas B3.1 + v-erbA cells showed a dramatic stimulation by this agent. Interestingly, in the presence of T3, the blockade in B3.1 + TR alpha 1 cell proliferation was accompanied by the down-regulation of the typical astrocytic genes, glial fibrillary acidic protein and vimentin. These hormone effects were not found in v-erbA-expressing cells. In addition, v-erbA inhibited the basal expression of the cyclic nucleotide phosphodiesterase gene, an oligodendrocytic marker.(ABSTRACT TRUNCATED AT 250 WORDS)

CD147/EMMPRIN Acts as a Functional Entry Receptor for Measles Virus on Epithelial Cells▿

PubMed Central

Watanabe, Akira; Yoneda, Misako; Ikeda, Fusako; Terao-Muto, Yuri; Sato, Hiroki; Kai, Chieko

2010-01-01

Measles is a highly contagious human disease caused by measles virus (MeV) and remains the leading cause of death in children, particularly in developing countries. Wild-type MeV preferentially infects lymphocytes by using signaling lymphocytic activation molecule (SLAM), whose expression is restricted to hematopoietic cells, as a receptor. MeV also infects other epithelial and neuronal cells that do not express SLAM and causes pneumonia and diarrhea and, sometimes, serious symptoms such as measles encephalitis and subacute sclerosing panencephalitis. The discrepancy between the tissue tropism of MeV and the distribution of SLAM-positive cells suggests that there are unknown receptors other than SLAM for MeV. Here we identified CD147/EMMPRIN (extracellular matrix metalloproteinase inducer), a transmembrane glycoprotein, which acts as a receptor for MeV on epithelial cells. Furthermore, we found the incorporation of cyclophilin B (CypB), a cellular ligand for CD147, in MeV virions, and showed that inhibition of CypB incorporation significantly attenuated SLAM-independent infection on epithelial cells, while it had no effect on SLAM-dependent infection. To date, MeV infection was considered to be triggered by binding of its hemagglutinin (H) protein and cellular receptors. Our present study, however, indicates that MeV infection also occurs via CD147 and virion-associated CypB, independently of MeV H. Since CD147 is expressed in a variety of cells, including epithelial and neuronal cells, this molecule possibly functions as an entry receptor for MeV in SLAM-negative cells. This is the first report among members of the Mononegavirales that CD147 is used as a virus entry receptor via incorporated CypB in the virions. PMID:20147391

Functional Characterization of CaVα2δ Mutations Associated with Sudden Cardiac Death*

PubMed Central

Bourdin, Benoîte; Shakeri, Behzad; Tétreault, Marie-Philippe; Sauvé, Rémy; Lesage, Sylvie; Parent, Lucie

2015-01-01

L-type Ca2+ channels play a critical role in cardiac rhythmicity. These ion channels are oligomeric complexes formed by the pore-forming CaVα1 with the auxiliary CaVβ and CaVα2δ subunits. CaVα2δ increases the peak current density and improves the voltage-dependent activation gating of CaV1.2 channels without increasing the surface expression of the CaVα1 subunit. The functional impact of genetic variants of CACNA2D1 (the gene encoding for CaVα2δ), associated with shorter repolarization QT intervals (the time interval between the Q and the T waves on the cardiac electrocardiogram), was investigated after recombinant expression of the full complement of L-type CaV1.2 subunits in human embryonic kidney 293 cells. By performing side-by-side high resolution flow cytometry assays and whole-cell patch clamp recordings, we revealed that the surface density of the CaVα2δ wild-type protein correlates with the peak current density. Furthermore, the cell surface density of CaVα2δ mutants S755T, Q917H, and S956T was not significantly different from the cell surface density of the CaVα2δ wild-type protein expressed under the same conditions. In contrast, the cell surface expression of CaVα2δ D550Y, CaVα2δ S709N, and the double mutant D550Y/Q917H was reduced, respectively, by ≈30–33% for the single mutants and by 60% for the latter. The cell surface density of D550Y/Q917H was more significantly impaired than protein stability, suggesting that surface trafficking of CaVα2δ was disrupted by the double mutation. Co-expression with D550Y/Q917H significantly decreased CaV1.2 currents as compared with results obtained with CaVα2δ wild type. It is concluded that D550Y/Q917H reduced inward Ca2+ currents through a defect in the cell surface trafficking of CaVα2δ. Altogether, our results provide novel insight in the molecular mechanism underlying the modulation of CaV1.2 currents by CaVα2δ. PMID:25527503

Epidemiology of goblet cell and microvesicular hyperplastic polyps.

PubMed

Qazi, Taha M; O'Brien, Michael J; Farraye, Francis A; Gould, Ryan W; Chen, Clara A; Schroy, Paul C

2014-12-01

Serrated polyps compromise both typical hyperplastic polyps as well as sessile serrated adenomas and dysplastic serrated polyps. Hyperplastic polyps exhibit two histological patterns: microvesicular hyperplastic polyps (MVHPs) and goblet cell hyperplastic polyps (GCHPs). MVHPs and GCHPs differ in their molecular signature. MVHPs have been frequently found to have the BRAF(V600E) mutation as well as aberrant methylation. In contrast, GCHPs have been associated with the KRAS mutation (KRAS-mut), which are infrequently seen in dysplastic serrated sessile adenomas. The particular risk factors that are associated with development of the types of hyperplastic polyps have not been previously studied. The purpose of this study is to characterize the associations between particular risk factors and the development of goblet cell or microvesicular hyperplastic polyps. We conducted a cross-sectional analysis of 3,543 asymptomatic, mostly average risk patients 50 and 79 years of age undergoing open-access screening colonoscopy between March 2005 and January 2012. Each patient was given a survey regarding 25 reputed risk factors for colorectal neoplasia and the responses were correlated with findings at colonoscopy. Associations between putative risk factors for colorectal neoplasia and MVHPs and GSHPs were examined using multiple logistic regression. MVHPS and GCHPs were identified in 5.3% and 8.7% of patients, respectively. The results of the statistical analysis indicate that a history of smoking greater than 20 years is associated with an increased risk of MVHPs (P<0.005) and GCHPs (P<0.005). An elevated BMI >30 kg/m(2) was also associated with the presence of MVHP at colonoscopy (P<0.005). Blacks and Asians appear to be protected from the development of MVHPs. In contrast, there was a positive association with the presence of GCHP at colonoscopy in blacks. The study suggests that the development of the distinct histological types of hyperplastic polyps are associated with distinct modifiable and non-modifiable lifestyle factors.

Intraorganellar acidification by V-ATPases: a target in cell proliferation and cancer therapy.

PubMed

Hernández, Agustín; Serrano, Gloria; Herrera-Palau, Rosana; Pérez-Castiñeira, José R; Serrano, Aurelio

2010-06-01

Vacuolar-type ATPases are multicomponent proton pumps involved in the acidification of single membrane intracellular compartments such as endosomes and lysosomes. They couple the hydrolysis of ATP to the translocation of one to two protons across the membrane. Acidification of the lumen of single membrane organelles is a necessary factor for the correct traffic of membranes and cargo to and from the different internal compartments of a cell. Also, V-ATPases are involved in regulation of pH at the cytosol and, possibly, extracellular milieu. The inhibition of V-ATPases has been shown to induce apoptosis and cell cycle arrest in tumour cells and, therefore, chemicals that behave as inhibitors of this kind of proton pumps have been proposed as putative treatment agents against cancer and many have been patented as such. The compounds filed in patents fall into five major types: plecomacrolides, benzolactone enamides, archazolids, chondropsins and indoles. All these have proved to be apoptosis inducers in cell culture and many to be able to reduce xenograft tumor growth in murine models. The present review will summarize their general structure, origin and mechanisms of action and put them in relation to the patents registered so far for the treatment of cancer.

Neonatal mucosal immunization with a non-living, non-genetically modified Lactococcus lactis vaccine carrier induces systemic and local Th1-type immunity and protects against lethal bacterial infection

PubMed Central

Ramirez, Karina; Ditamo, Yanina; Rodriguez, Liliana; Picking, Wendy L.; van Roosmalen, Maarten L.; Leenhouts, Kees; Pasetti, Marcela F.

2010-01-01

Safe and effective immunization of newborns and infants can significantly reduce childhood mortality, yet conventional vaccines have been largely unsuccessful in stimulating the neonatal immune system. We explored the capacity of a novel mucosal antigen delivery system consisting of non-living, non-genetically modified Lactococcus lactis particles, designated Gram-positive Enhancer Matrix (GEM), to induce immune responses in the neonatal setting. Yersinia pestis LcrV, used as model protective antigen, was displayed on the GEM particles. Newborn mice immunized intranasally with GEM-LcrV developed LcrV-specific antibodies, Th1-type cell-mediated immunity, and were protected against lethal Y. pestis (plague) infection. The GEM particles activated and enhanced the maturation of neonatal dendritic cells both in vivo and in vitro. These dendritic cells showed increased capacities for secretion of pro-inflammatory and Th1-cell polarizing cytokines, antigen presentation and stimulation of CD4+ and CD8+ T cells. These data show that mucosal immunization with L. lactis GEM particles carrying vaccine antigens represents a promising approach to prevent infectious diseases early in life. PMID:19924118

Radiobiological description of the LET dependence of the cell survival of oxic and anoxic cells irradiated by carbon ions.

PubMed

Antonovic, L; Brahme, A; Furusawa, Y; Toma-Dasu, I

2013-01-01

Light-ion radiation therapy against hypoxic tumors is highly curative due to reduced dependence on the presence of oxygen in the tumor at elevated linear energy transfer (LET) towards the Bragg peak. Clinical ion beams using spread-out Bragg peak (SOBP) are characterized by a wide spectrum of LET values. Accurate treatment optimization requires a method that can account for influence of the variation in response for a broad range of tumor hypoxia, absorbed doses and LETs. This paper presents a parameterization of the Repairable Conditionally-Repairable (RCR) cell survival model that can describe the survival of oxic and hypoxic cells over a wide range of LET values, and investigates the relationship between hypoxic radiation resistance and LET. The biological response model was tested by fitting cell survival data under oxic and anoxic conditions for V79 cells irradiated with LETs within the range of 30-500 keV/µm. The model provides good agreement with experimental cell survival data for the range of LET investigated, confirming the robustness of the parameterization method. This new version of the RCR model is suitable for describing the biological response of mixed populations of oxic and hypoxic cells and at the same time taking into account the distribution of doses and LETs in the incident beam and its variation with depth in tissue. The model offers a versatile tool for the selection of LET and dose required in the optimization of the therapeutic effect, without severely affecting normal tissue in realistic tumors presenting highly heterogeneous oxic and hypoxic regions.

45 CFR 79.21 - Discovery.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discovery. 79.21 Section 79.21 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for...

45 CFR 79.21 - Discovery.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 1 2014-10-01 2014-10-01 false Discovery. 79.21 Section 79.21 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for...

45 CFR 79.21 - Discovery.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 1 2013-10-01 2013-10-01 false Discovery. 79.21 Section 79.21 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for...

45 CFR 79.21 - Discovery.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 1 2011-10-01 2011-10-01 false Discovery. 79.21 Section 79.21 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for...

45 CFR 79.21 - Discovery.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false Discovery. 79.21 Section 79.21 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for...

Inhibition of SET Domain–Containing Lysine Methyltransferase 7/9 Ameliorates Renal Fibrosis

PubMed Central

Sasaki, Kensuke; Nakashima, Ayumu; Irifuku, Taisuke; Yamada, Kyoko; Kokoroishi, Keiko; Ueno, Toshinori; Doi, Toshiki; Hida, Eisuke; Arihiro, Koji; Kohno, Nobuoki

2016-01-01

TGF-β1 activity results in methylation of lysine 4 of histone H3 (H3K4) through SET domain–containing lysine methyltransferase 7/9 (SET7/9) induction, which is important for the transcriptional activation of fibrotic genes in vitro. However, in vivo studies utilizing an experimental model of renal fibrosis are required to develop therapeutic interventions that target SET7/9. In this study, we investigated the signaling pathway of TGF-β1-induced SET7/9 expression and whether inhibition of SET7/9 suppresses renal fibrosis in unilateral ureteral obstruction (UUO) mice and kidney cell lines. Among the SET family, SET7/9 was upregulated on days 3 and 7 in UUO mice, and the upregulation was suppressed by TGF-β1 neutralizing antibody. TGF-β1 induced SET7/9 expression via Smad3 in normal rat kidney (NRK)-52E cells. In human kidney biopsy specimens from patients diagnosed with IgA nephropathy and membranous nephropathy, SET7/9 expression was positively correlated with the degree of interstitial fibrosis (r=0.59, P=0.001 in patients with IgA nephropathy; and r=0.58, P<0.05 in patients with membranous nephropathy). In addition, small interfering RNA-mediated knockdown of SET7/9 expression significantly attenuated renal fibrosis in UUO mice. Sinefungin, an inhibitor of SET7/9, also suppressed the expression of mesenchymal markers and extracellular matrix proteins and inhibited H3K4 mono-methylation (H3K4me1) in kidneys of UUO mice. Moreover, sinefungin had an inhibitory effect on TGF-β1-induced α-smooth muscle actin expression and H3K4me1 in both NRK-52E and NRK-49F cells. In conclusion, sinefungin, a SET7/9 inhibitor, ameliorates renal fibrosis by inhibiting H3K4me1 and may be a candidate therapeutic agent. PMID:26045091

The physiological and pathophysiological functions of renal and extrarenal vasopressin V2 receptors.

PubMed

Juul, Kristian Vinter; Bichet, Daniel G; Nielsen, Søren; Nørgaard, Jens Peter

2014-05-01

The arginine vasopressin (AVP) type 2 receptor (V2R) is unique among AVP receptor subtypes in signaling through cAMP. Its key function is in the kidneys, facilitating the urine concentrating mechanism through the AVP/V2 type receptor/aquaporin 2 system in the medullary and cortical collecting ducts. Recent clinical and research observations strongly support the existence of an extrarenal V2R. The clinical importance of the extrarenal V2R spans widely from stimulation of coagulation factor in the endothelium to as yet untested potential therapeutic targets. These include V2R-regulated membranous fluid turnover in the inner ear, V2R-regulated mitogensis and apoptosis in certain tumor tissues, and numerous other cell types where the physiological role of V2Rs still requires further research. Here, we review current evidence on the physiological and pathophysiological functions of renal and extrarenal V2Rs. These functions of V2R are important, not only in rare diseases with loss or gain of function of V2R but also in relation to the recent use of nonpeptide V2R antagonists to treat hyponatremia and possibly retard the growth of cysts and development of renal failure in autosomal dominant polycystic kidney disease. The main functions of V2R in principal cells of the collecting duct are water, salt, and urea transport by modifying the trafficking of aquaporin 2, epithelial Na(+) channels, and urea transporters and vasodilation and stimulation of coagulation factor properties, mainly seen with pharmacological doses of 1-desamino-8-D-AVP. The AVPR2 gene is located on the X chromosome, in a region with high probability of escape from inactivation; this may lead to phenotypic sex differences, with females expressing higher levels of transcript than males.

High Pressure Elastic Behavior of Synthetic Mg 3 Y 2 (SiO 4 ) 3 Garnet up to 9 GPa

DOE PAGES

Fan, Dawei; Ma, Maining; Wei, Shuyi; ...

2013-01-01

Tmore » he compression behavior of synthetic magnesium- (Mg-) yttrium (Y) garnet Mg 3 Y 2 (SiO 4 ) 3 has been investigated upto about 8.79 GPa at 300 K using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at the beamline X17C, National Synchrotron Light Source, Brookhaven National Laboratory. No phase transition has been observed within the pressure range investigated. he unit-cell parameters and volume decreased systematically with increasing pressure, and a reliable isothermal bulk modulus ( K 0 ) and its pressure derivative ( K 0 ′ ) were obtained in this study. he values of zero-pressure volume V 0 , K 0 , and K 0 ′ refined with a third-order Birch-Murnaghan equation of state are V 0 = 1727.9 ± 0.2  Å 3 , K 0 = 145 ± 3  GPa, and K 0 ′ = 8.5 ± 0.9 . If K 0 ′ is fixed at 4, K 0 is obtained as 158 ± 2  GPa.« less

High Pressure Elastic Behavior of Synthetic Mg 3 Y 2 (SiO 4 ) 3 Garnet up to 9 GPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, Dawei; Ma, Maining; Wei, Shuyi

Tmore » he compression behavior of synthetic magnesium- (Mg-) yttrium (Y) garnet Mg 3 Y 2 (SiO 4 ) 3 has been investigated upto about 8.79 GPa at 300 K using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at the beamline X17C, National Synchrotron Light Source, Brookhaven National Laboratory. No phase transition has been observed within the pressure range investigated. he unit-cell parameters and volume decreased systematically with increasing pressure, and a reliable isothermal bulk modulus ( K 0 ) and its pressure derivative ( K 0 ′ ) were obtained in this study. he values of zero-pressure volume V 0 , K 0 , and K 0 ′ refined with a third-order Birch-Murnaghan equation of state are V 0 = 1727.9 ± 0.2  Å 3 , K 0 = 145 ± 3  GPa, and K 0 ′ = 8.5 ± 0.9 . If K 0 ′ is fixed at 4, K 0 is obtained as 158 ± 2  GPa.« less

A microfluidic flow-through device for high throughput electrical lysis of bacterial cells based on continuous dc voltage.

PubMed

Wang, Hsiang-Yu; Bhunia, Arun K; Lu, Chang

2006-12-15

Interest in electrical lysis of biological cells on a microfludic platform has increased because it allows for the rapid recovery of intracellular contents without introducing lytic agents. In this study we demonstrated a simple microfluidic flow-through device which lysed Escherichia coli cells under a continuous dc voltage. The E. coli cells had previously been modified to express green fluorescent protein (GFP). In our design, the cell lysis only happened in a defined section of a microfluidic channel due to the local field amplification by geometric modification. The geometric modification also effectively decreased the required voltage for lysis by several folds. We found that local field strength of 1000-1500 V/cm was required for nearly 100% cell death. This threshold field strength was considerably lower than the value reported in the literature, possibly due to the longer duration of the field [Lee, S.W., Tai, Y.C., 1999. Sens. Actuators A: Phys. 73, 74-79]. Cell lysis was detected by both plate count and fluorescence spectroscopy. The cell membrane was completely disintegrated in the lysis section of the microfluidic device, when the field strength was higher than 2000 V/cm. The devices were fabricated using low-cost soft lithography with channel widths considerably larger than the cell size to avoid clogging and ensure stable performance. Our tool will be ideal for high throughput processing of bacterial cells for chemical analysis of intracellular contents such as DNA and proteins. The application of continuous dc voltage greatly simplified the instrumentation compared to devices using electrical pulses for similar purposes. In principle, the same approach can also be applied for lysis of mammalian cells and electroporative transfection.

Simultaneous Inhibition of PI3Kδ and PI3Kα Induces ABC-DLBCL Regression by Blocking BCR-Dependent and -Independent Activation of NF-κB and AKT.

PubMed

Paul, Juliane; Soujon, Maurice; Wengner, Antje M; Zitzmann-Kolbe, Sabine; Sturz, Andrea; Haike, Katja; Keng Magdalene, Koh Hui; Tan, Sze Huey; Lange, Martin; Tan, Soo Yong; Mumberg, Dominik; Lim, Soon Thye; Ziegelbauer, Karl; Liu, Ningshu

2017-01-09

Compared with follicular lymphoma, high PI3Kα expression was more prevalent in diffuse large B cell lymphoma (DLBCL), although both tumor types expressed substantial PI3Kδ. Simultaneous inhibition of PI3Kα and PI3Kδ dramatically enhanced the anti-tumor profile in ABC-DLBCL models compared with selective inhibition of PI3Kδ, PI3Kα, or BTK. The anti-tumor activity was associated with suppression of p-AKT and a mechanism of blocking nuclear factor-κB activation driven by CD79 mut , CARD11 mut , TNFAIP3 mut , or MYD88 mut . Inhibition of PI3Kα/δ resulted in tumor regression in an ibrutinib-resistant CD79B WT /MYD88 mut patient-derived ABC-DLBCL model. Furthermore, rebound activation of BTK and AKT was identified as a mechanism limiting CD79B mut -ABC-DLBCL to show a robust response to PI3K and BTK inhibitor monotherapies. A combination of ibrutinib with the PI3Kα/δ inhibitor copanlisib produced a sustained complete response in vivo in CD79B mut /MYD88 mut ABC-DLBCL models. Copyright © 2017 Elsevier Inc. All rights reserved.

Enzymatic synthesis of extra virgin olive oil based infant formula fat analogues containing ARA and DHA: one-stage and two-stage syntheses.

PubMed

Pande, Garima; Sabir, Jamal S M; Baeshen, Nabih A; Akoh, Casimir C

2013-11-06

Structured lipids (SLs) with high palmitic acid content at the sn-2 position enriched with arachidonic acid (ARA) and docosahexaenoic acid (DHA) were produced using extra virgin olive oil, tripalmitin, ARA and DHA single cell oil free fatty acids. Four types of SLs were synthesized using immobilized lipases, Novozym 435 and Lipozyme TL IM, based on one-stage (one-pot) and two-stage (sequential) syntheses. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, melting and crystallization profiles, tocopherols, and phenolic compounds. All the SLs had >50 mol % palmitic acid at the sn-2 position. The predominant TAGs in all SLs were PPO and OPO. The total tocopherol content of SL1-1, SL1-2, SL2-1, and SL2-2 were 70.46, 68.79, 79.64, and 79.31 μg/g, respectively. SL1-2 had the highest melting completion (42.0 °C) and crystallization onset (27.6 °C) temperatures. All the SLs produced in this study may be suitable as infant formula fat analogues.

Pure Single-Crystalline Na1.1V3O7.9 Nanobelts as Superior Cathode Materials for Rechargeable Sodium-Ion Batteries.

PubMed

Yuan, Shuang; Liu, Yong-Bing; Xu, Dan; Ma, De-Long; Wang, Sai; Yang, Xiao-Hong; Cao, Zhan-Yi; Zhang, Xin-Bo

2015-03-01

Pure single-crystalline Na 1.1 V 3 O 7.9 nanobelts are successfully synthesized for the first time via a facile yet effective strategy. When used as cathode materials for Na-ion batteries, the novel nanobelts exhibit excellent electrochemical performance. Given the ease and effectiveness of the synthesis route as well as the very promising electrochemical performance, the results obtained may be extended to other next-generation cathode materials for Na-ion batteries.

Quinone Reduction by the Na+-Translocating NADH Dehydrogenase Promotes Extracellular Superoxide Production in Vibrio cholerae▿ †

PubMed Central

Lin, Po-Chi; Türk, Karin; Häse, Claudia C.; Fritz, Günter; Steuber, Julia

2007-01-01

The pathogenicity of Vibrio cholerae is influenced by sodium ions which are actively extruded from the cell by the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR). To study the function of the Na+-NQR in the respiratory chain of V. cholerae, we examined the formation of organic radicals and superoxide in a wild-type strain and a mutant strain lacking the Na+-NQR. Upon reduction with NADH, an organic radical was detected in native membranes by electron paramagnetic resonance spectroscopy which was assigned to ubisemiquinones generated by the Na+-NQR. The radical concentration increased from 0.2 mM at 0.08 mM Na+ to 0.4 mM at 14.7 mM Na+, indicating that the concentration of the coupling cation influences the redox state of the quinone pool in V. cholerae membranes. During respiration, V. cholerae cells produced extracellular superoxide with a specific activity of 10.2 nmol min−1 mg−1 in the wild type compared to 3.1 nmol min−1 mg−1 in the NQR deletion strain. Raising the Na+ concentration from 0.1 to 5 mM increased the rate of superoxide formation in the wild-type V. cholerae strain by at least 70%. Rates of respiratory H2O2 formation by wild-type V. cholerae cells (30.9 nmol min−1 mg−1) were threefold higher than rates observed with the mutant strain lacking the Na+-NQR (9.7 nmol min−1 mg−1). Our study shows that environmental Na+ could stimulate ubisemiquinone formation by the Na+-NQR and hereby enhance the production of reactive oxygen species formed during the autoxidation of reduced quinones. PMID:17322313