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Sample records for vero cells grown

  1. Human Respiratory Syncytial Virus Memphis 37 Grown in HEp-2 Cells Causes more Severe Disease in Lambs than Virus Grown in Vero Cells

    PubMed Central

    Derscheid, Rachel J.; van Geelen, Albert; McGill, Jodi L.; Gallup, Jack M.; Cihlar, Tomas; Sacco, Randy E.; Ackermann, Mark R.

    2013-01-01

    Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in infants and young children. A small percentage of these individuals develop severe and even fatal disease. To better understand the pathogenesis of severe disease and develop therapies unique to the less-developed infant immune system, a model of infant disease is needed. The neonatal lamb pulmonary development and physiology is similar to that of infants, and sheep are susceptible to ovine, bovine, or human strains of RSV. RSV grown in Vero (African green monkey) cells has a truncated attachment G glycoprotein as compared to that grown in HEp-2 cells. We hypothesized that the virus grown in HEp-2 cells would cause more severe clinical symptoms and cause more severe pathology. To confirm the hypothesis, lambs were inoculated simultaneously by two different delivery methods (intranasal and nebulized inoculation) with either Vero-grown or HEp-2-grown RSV Memphis 37 (M37) strain of virus to compare viral infection and disease symptoms. Lambs infected with HEp-2 cell-derived virus by either intranasal or nebulization inoculation had significantly higher levels of viral RNA in lungs as well as greater clinical disease including both gross and histopathologic lesions compared to lambs similarly inoculated with Vero-grown virus. Thus, our results provide convincing in vivo evidence for differences in viral infectivity that corroborate previous in vitro mechanistic studies demonstrating differences in the G glycoprotein expression by RSV grown in Vero cells. PMID:24284879

  2. Analysis of Vero cell growth behavior on microcarrier by means of environmental scanning electron microscopy.

    PubMed

    Shao, Manjun; Jiang, Lei; Cong, Wei; Ouyang, Fan

    2002-04-01

    By using environmental scanning electron microscopy, the morphological changes of Vero cells attached to and grown on the microcarrier Cytodex-3 were observed, and their behavior of adhesion, spreading and proliferation was analyzed. The effect of exogenous fibronectin/ laminin on adhesion and spreading of MCC/Vero cell was studied. The images of ESEM showed that expansion of cell growth was directed toward vacancy space. The growth curve and cell concentration change during the whole culture process were obtained from the statistical counting method based on ESEM images and the crystal violet method. The growth rate of Vero cells increases with increasing the concentration of cell inoculation, that is, the specific growth rate increases quickly with increasing the concentration of cell inoculation. When serum concentration in medium #199 ranged from 5% to 10%, experimental results indicated that serum concentration is one of the important factors influencing cell growth, particularly in the cell adhesion and spreading stage. PMID:18763074

  3. Increasing Vero viable cell densities for yellow fever virus production in stirred-tank bioreactors using serum-free medium.

    PubMed

    Mattos, Diogo A; Silva, Marlon V; Gaspar, Luciane P; Castilho, Leda R

    2015-08-20

    In this work, changes in Vero cell cultivation methods have been employed in order to improve cell growth conditions to obtain higher viable cell densities and to increase viral titers. The propagation of the 17DD yellow fever virus (YFV) in Vero cells grown on Cytodex I microcarriers was evaluated in 3-L bioreactor vessels. Prior to the current changes, Vero cells were repeatedly displaying insufficient microcarrier colonization. A modified cultivation process with four changes has resulted in higher cell densities and higher virus titers than previously observed for 17DD YFV. PMID:25930117

  4. High Genetic Stability of Dengue Virus Propagated in MRC-5 Cells as Compared to the Virus Propagated in Vero Cells

    PubMed Central

    Butler, Michael; Wu, Suh-Chin

    2008-01-01

    This work investigated the replication kinetics of the four dengue virus serotypes (DEN-1 to DEN-4), including dengue virus type 4 (DEN-4) recovered from an infectious cDNA clone, in Vero cells and in MRC-5 cells grown on Cytodex 1 microcarriers. DEN-1 strain Hawaii, DEN-2 strain NGC, DEN-3 strain H-87, and DEN-4 strain H-241 , and DEN-4 strain 814669 derived from cloned DNA, were used to infect Vero cells and MRC-5 cells grown in serum-free or serum-containing microcarrier cultures. Serum-free and serum-containing cultures were found to yield comparable titers of these viruses. The cloned DNA-derived DEN-4 started genetically more homogeneous was used to investigate the genetic stability of the virus propagated in Vero cells and MRC-5 cells. Sequence analysis revealed that the DEN-4 propagated in MRC-5 cells maintained a high genetic stability, compared to the virus propagated in Vero cells. Amino acid substitutions of Gly104Cys and Phe108Ile were detected at 70%, 60%, respectively, in the envelope (E) protein of DEN-4 propagated in Vero cells, whereas a single mutation of Glu345Lys was detected at 50% in E of the virus propagated in MRC-5 cells. Sequencing of multiple clones of three separate DNA fragments spanning 40% of the genome also indicated that DEN-4 propagated in Vero cells contained a higher number of mutations than the virus growing in MRC-5 cells. Although Vero cells yielded a peak virus titer approximately 1 to 17 folds higher than MRC-5 cells, cloned DEN-4 from MRC-5 cells maintained a greater stability than the virus from Vero cells. Serum-free microcarrier cultures of MRC-5 cells offer a potentially valuable system for the large-scale production of live-attenuated DEN vaccines. PMID:18350148

  5. Statistical optimization of influenza H1N1 production from batch cultures of suspension Vero cells (sVero).

    PubMed

    Paillet, Cristian; Forno, Guillermina; Soldano, Nicolas; Kratje, Ricardo; Etcheverrigaray, Marina

    2011-09-22

    Efficient vaccine production requires the growth of large quantities of virus produced with high yield from a safe host system. Human influenza vaccines are produced in embryonated chicken eggs. However, over the last decade many efforts have allowed the establishment of cell culture-derived vaccines. We generated a Vero cell line adapted to grow in suspension (sVero) in a serum-free medium and evaluated it for its potential as host cell for influenza vaccine production. Initially we studied the capacity of sVero cells to grow in the presence of incremental concentrations of trypsin. In comparison with adherent Vero cells (aVero), we found that sVero cells maintain their growth kinetics even with a three-fold increase in trypsin concentration. The influence of the conditions of infection on the yield of H1N1 produced in serum-free suspension cultures of sVero cells was investigated by a 2(2) full factorial experiment with center point. Each experiment tested the influence of the multiplicity of infection (m.o.i.) and trypsin concentration, on production yields at two levels, in four possible combinations of levels and conditions, plus a further combination in which each condition was set in the middle of its extreme levels. On the basis of software analysis, a combination of m.o.i. of 0.0066TCID(50%)/cell and trypsin concentration of 5μg/1.0×10(6) cells with a desirability of 0.737 was selected as the optimized condition for H1N1 production in sVero cells. Our results show the importance of proper selection of infection conditions for H1N1 production on sVero cells in serum-free medium. PMID:21756959

  6. Propagation and Titration of West Nile Virus on Vero Cells.

    PubMed

    McAuley, Alexander J; Beasley, David W C

    2016-01-01

    The propagation and titration of viruses are key virological techniques. Unlike other flaviviruses, such as the dengue viruses, West Nile virus (WNV) grows and plaques very efficiently on Vero cells, usually inducing strong cytopathic effect (CPE) and forming clear plaques. Here, we outline the steps for propagating WNV from culture supernatant stocks and homogenized organ/mosquito samples, as well as for determining virus titers in samples by serial-dilution plaque assay using neutral red or crystal violet stains. PMID:27188547

  7. Completion of the Entire Hepatitis C Virus Life Cycle in Vero Cells Derived from Monkey Kidney

    PubMed Central

    Murayama, Asako; Sugiyama, Nao; Wakita, Takaji

    2016-01-01

    ABSTRACT A hepatitis C virus (HCV) cell culture system incorporating the JFH-1 strain and the human hepatoma cell line HuH-7 enabled the production of infectious HCV particles. Several host factors were identified as essential for HCV replication. Supplementation of these factors in nonhepatic human cell lines enabled HCV replication and particle production. Vero cells established from monkey kidney are commonly used for the production of vaccines against a variety of viruses. In this study, we aimed to establish a novel Vero cell line to reconstruct the HCV life cycle. Unmodified Vero cells did not allow HCV infection or replication. The expression of microRNA 122 (miR-122), an essential factor for HCV replication, is notably low in Vero cells. Therefore, we supplemented Vero cells with miR-122 and found that HCV replication was enhanced. However, Vero cells that expressed miR-122 still did not allow HCV infection. We supplemented HCV receptor molecules and found that scavenger receptor class B type I (SRBI) was essential for HCV infection in Vero cells. The supplementation of apolipoprotein E (ApoE), a host factor important for virus production, enabled the production of infectious virus in Vero cells. Finally, we created a Vero cell line that expressed the essential factors miR-122, SRBI, and ApoE; the entire HCV life cycle, including infection, replication, and infectious virus production, was completed in these cells. In conclusion, we demonstrated that miR-122, SRBI, and ApoE were necessary and sufficient for the completion of the entire HCV life cycle in nonhuman, nonhepatic Vero cells. PMID:27302754

  8. Susceptibility of the VERO line of African green monkey kidney cells to human enteroviruses

    PubMed Central

    Davis, Patricia M.; Phillpotts, R. J.

    1974-01-01

    The relative susceptibility of VERO cells and primary rhesus monkey kidney cells to 47 prototype strains of human enteroviruses is described. Of these strains, types 4, 14, 16, 17, 18, 21, 31 and 34 and Coxsackie virus A 9 failed to cause CPE in the VERO cells whilst only one, echovirus type 34, failed to cause CPE in the monkey kidney cells. A comparison is given of the efficiency of the two cell cultures for enterovirus isolation from clinical material. Results show that VERO cells are as useful as primary monkey kidney for the isolation of Coxsackie B viruses but less satisfactory for isolating echoviruses. They are satisfactory for the isolation of single types of poliovirus and appear to be more satisfactory than primary monkey kidney cells for the isolation of mixtures of polioviruses. The identification of enteroviruses by neutralization tests in VERO cells is successful. PMID:4361500

  9. Preventing Cleavage of the Respiratory Syncytial Virus Attachment Protein in Vero Cells Rescues the Infectivity of Progeny Virus for Primary Human Airway Cultures

    PubMed Central

    Corry, Jacqueline; Johnson, Sara M.; Cornwell, Jessica

    2015-01-01

    ABSTRACT All live attenuated respiratory syncytial virus (RSV) vaccines that have advanced to clinical trials have been produced in Vero cells. The attachment (G) glycoprotein in virions produced in these cells is smaller than that produced in other immortalized cells due to cleavage. These virions are 5-fold less infectious for primary well-differentiated human airway epithelial (HAE) cell cultures. Because HAE cells are isolated directly from human airways, Vero cell-grown vaccine virus would very likely be similarly inefficient at initiating infection of the nasal epithelium following vaccination, and therefore, a larger inoculum would be required for effective vaccination. We hypothesized that Vero cell-derived virus containing an intact G protein would be more infectious for HAE cell cultures. Using protease inhibitors with increasing specificity, we identified cathepsin L to be the protease responsible for cleavage. Our evidence suggests that cleavage occurs in the late endosome or lysosome during endocytic recycling. Cathepsin L activity was 100-fold greater in Vero cells than in HeLa cells. In addition, cathepsin L was able to cleave the G protein in Vero cell-grown virions but not in HeLa cell-grown virions, suggesting a difference in G-protein posttranslational modification in the two cell lines. We identified by mutagenesis amino acids important for cleavage, and these amino acids included a likely cathepsin L cleavage site. Virus containing a modified, noncleavable G protein produced in Vero cells was 5-fold more infectious for HAE cells in culture, confirming our hypothesis and indicating the value of including such a mutation in future live attenuated RSV vaccines. IMPORTANCE Worldwide, RSV is the second leading infectious cause of infant death, but no vaccine is available. Experimental live attenuated RSV vaccines are grown in Vero cells, but during production the virion attachment (G) glycoprotein is cleaved. Virions containing a cleaved G protein

  10. Proteomic Analysis of Membrane Proteins of Vero Cells: Exploration of Potential Proteins Responsible for Virus Entry

    PubMed Central

    Guo, Donghua; Zhu, Qinghe; Zhang, Hong

    2014-01-01

    Vero cells are highly susceptible to many viruses in humans and animals, and its membrane proteins (MPs) are responsible for virus entry. In our study, the MP proteome of the Vero cells was investigated using a shotgun LC-MS/MS approach. Six hundred twenty-seven proteins, including a total of 1839 peptides, were identified in MP samples of the Vero cells. In 627 proteins, 307 proteins (48.96%) were annotated in terms of biological process of gene ontology (GO) categories; 356 proteins (56.78%) were annotated in terms of molecular function of GO categories; 414 proteins (66.03%) were annotated in terms of cellular components of GO categories. Of 627 identified proteins, seventeen proteins had been revealed to be virus receptor proteins. The resulting protein lists and highlighted proteins may provide valuable information to increase understanding of virus infection of Vero cells. PMID:24286161

  11. The Genome Landscape of the African Green Monkey Kidney-Derived Vero Cell Line

    PubMed Central

    Osada, Naoki; Kohara, Arihiro; Yamaji, Toshiyuki; Hirayama, Noriko; Kasai, Fumio; Sekizuka, Tsuyoshi; Kuroda, Makoto; Hanada, Kentaro

    2014-01-01

    Continuous cell lines that originate from mammalian tissues serve as not only invaluable tools for life sciences, but also important animal cell substrates for the production of various types of biological pharmaceuticals. Vero cells are susceptible to various types of microbes and toxins and have widely contributed to not only microbiology, but also the production of vaccines for human use. We here showed the genome landscape of a Vero cell line, in which 25,877 putative protein-coding genes were identified in the 2.97-Gb genome sequence. A homozygous ∼9-Mb deletion on chromosome 12 caused the loss of the type I interferon gene cluster and cyclin-dependent kinase inhibitor genes in Vero cells. In addition, an ∼59-Mb loss of heterozygosity around this deleted region suggested that the homozygosity of the deletion was established by a large-scale conversion. Moreover, a genomic analysis of Vero cells revealed a female Chlorocebus sabaeus origin and proviral variations of the endogenous simian type D retrovirus. These results revealed the genomic basis for the non-tumourigenic permanent Vero cell lineage susceptible to various pathogens and will be useful for generating new sub-lines and developing new tools in the quality control of Vero cells. PMID:25267831

  12. The spike protein of severe acute respiratory syndrome (SARS) is cleaved in virus infected Vero-E6 cells.

    PubMed

    Wu, Xiao Dong; Shang, Bo; Yang, Rui Fu; Yu, Hao; Ma, Zhi Hai; Shen, Xu; Ji, Yong Yong; Lin, Ying; Wu, Ya Di; Lin, Guo Mei; Tian, Lin; Gan, Xiao Qing; Yang, Sheng; Jiang, Wei Hong; Dai, Er Hei; Wang, Xiao Yi; Jiang, Hua Liang; Xie, You Hua; Zhu, Xue Liang; Pei, Gang; Li, Lin; Wu, Jia Rui; Sun, Bing

    2004-10-01

    Spike protein is one of the major structural proteins of severe acute respiratory syndrome-coronavirus. It is essential for the interaction of the virons with host cell receptors and subsequent fusion of the viral envelop with host cell membrane to allow infection. Some spike proteins of coronavirus, such as MHV, HCoV-OC43, AIBV and BcoV, are proteolytically cleaved into two subunits, S1 and S2. In contrast, TGV, FIPV and HCoV-229E are not. Many studies have shown that the cleavage of spike protein seriously affects its function. In order to investigate the maturation and proteolytic processing of the S protein of SARS CoV, we generated S1 and S2 subunit specific antibodies (Abs) as well as N, E and 3CL protein-specific Abs. Our results showed that the antibodies could efficiently and specifically bind to their corresponding proteins from E.coli expressed or lysate of SARS-CoV infected Vero-E6 cells by Western blot analysis. Furthermore, the anti-S1 and S2 Abs were proved to be capable of binding to SARS CoV under electron microscope observation. When S2 Ab was used to perform immune precipitation with lysate of SARS-CoV infected cells, a cleaved S2 fragment was detected with S2-specific mAb by Western blot analysis. The data demonstrated that the cleavage of S protein was observed in the lysate, indicating that proteolytic processing of S protein is present in host cells. PMID:15450134

  13. Pre-clinical development of cell culture (Vero)-derived H5N1 pandemic vaccines.

    PubMed

    Howard, M Keith; Kistner, Otfried; Barrett, P Noel

    2008-05-01

    The rapid spread of avian influenza (H5N1) and its transmission to humans has raised the possibility of an imminent pandemic and concerns over the ability of standard influenza vaccine production methods to supply sufficient amounts of an effective vaccine. We report here on a robust and flexible strategy which uses wild-type virus grown in a continuous cell culture (Vero) system to produce an inactivated whole virus vaccine. Candidate vaccines based on clade 1 and clade 2 influenza H5N1 strains, produced at a variety of manufacturing scales, were demonstrated to be highly immunogenic in animal models without the need for adjuvant. The vaccines induce cross-neutralising antibodies and are protective in a mouse challenge model not only against the homologous virus but against other H5N1 strains, including those from other clades. These data indicate that cell culture-grown, whole virus vaccines, based on the wild-type virus, allow the rapid high-yield production of a candidate pandemic vaccine. PMID:18953724

  14. Antiproliferative efficacy of Tabernaemontana divaricata against HEP2 cell line and Vero cell line

    PubMed Central

    Kumar, Arvind; Selvakumar, S.

    2015-01-01

    Background: Laryngeal cancer may also be called cancer of the larynx or laryngeal carcinoma. Conventional plants are a precious source of novel anticancer agents and are still in performance better role in health concern. The study was intended to estimation of the anticancer activity of the chloroformic extract of Tabernaemontana divaricata on the human epidermoid larynx carcinoma cell line (Hep 2). Materials and Method: The aerial parts (leaves, stem, and flowers) of T. divaricata were tested for its inhibitory effect in 96 microplate formats against Hep 2 cell line. The anticancer activity of samples on Hep 2 and Vero was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and various enzymatic parameters like catalase, reduced glutathione (GSH), GSH peroxidase, and superoxide anion scavenging activity. Viable cells were determined by the absorbance at 540 nm. Measurements were performed, and the concentration required for a 50% inhibition of viability (IC50) was determined graphically. The effect of the samples on the proliferation of Hep 2 and Vero cells was expressed as the % cell viability. Results: The extract on Hep 2 cell line up to 7.8 μg/ml and that IC50 value on Hep 2 cell line was 112 μg whereas 94 μg for Vero cell line. Hence, T. divaricata has lesser significant action on Vero cell line. Conclusion: Medicinal plant drug discovery continues to provide new and important leads against various pharmacological targets including cancer. Our results clearly indicate the anticancer property of the medicinal plant T. divaricata against the human laryngeal carcinoma cell lines (Hep 2 cell line). PMID:26109773

  15. Receptor-mediated entry of diphtheria toxin into monkey kidney (Vero) cells: electron microscopic evaluation.

    PubMed Central

    Morris, R E; Gerstein, A S; Bonventre, P F; Saelinger, C B

    1985-01-01

    To express toxicity in living cells, diphtheria toxin (DT) must cross a membrane barrier and reach its target in the cytosol. Here we examine the entry of DT into the toxin-sensitive monkey kidney (Vero) cells. Using electron microscopy we directly demonstrated for the first time that DT is internalized by receptor-mediated endocytosis, i.e., via clathrin-coated pits, and enters the endosomal system. Methylamine, which is known to protect cells from DT, stopped the movement of toxin to coated areas of the cell membrane. In the presence of amine, prebound biotinyl-DT was internalized, but toxicity was inhibited. Biochemical evidence revealed that methylamine maintained toxin molecules at a site accessible to neutralization by antitoxin. The data suggest that DT entering Vero cells in the presence of methylamine is sequestered within the cell and does not express toxicity. Images PMID:4066029

  16. Binding Component of Clostridium perfringens Iota-Toxin Induces Endocytosis in Vero Cells

    PubMed Central

    Nagahama, Masahiro; Nagayasu, Koichi; Kobayashi, Keiko; Sakurai, Jun

    2002-01-01

    Clostridium perfringens iota-toxin is a binary toxin consisting of two individual proteins, the binding component (Ib) and the enzyme component (Ia). Wild-type Ib bound to Vero cells at 4 and 37°C and formed oligomers at 37°C but not at 4°C. The Ib-induced K+ release from the cells was dependent on the oligomer formation of Ib in the cells, but the oligomer formation did not induce rounding activity or cytotoxicity. After incubation of the cells with recombinant Ib (rIb) at 37°C, the Ib oligomer in the cell became resistant to pronase treatment with time, but the Ib monomer was sensitive to the treatment. Furthermore, treatment of Vero cells with rIb in the presence of bafilomycin, methylamine, or ethylamine resulted in accumulation of the oligomer in the cells but had no effect on K+ release. Moreover, incubation with Ib plus Ia in the presence of these agents caused no rounding in the cells. These observations suggest that Ib binds to Vero cells, itself oligomerizing to form ion-permeable channels and that the formation of oligomer then induces endocytosis. PMID:11895954

  17. Characterization of homologous defective interfering RNA during persistent infection of Vero cells with Japanese encephalitis virus.

    PubMed

    Yoon, Sung Wook; Lee, Sang-Yong; Won, Sung-Yong; Park, Sun-Hee; Park, Soo-Young; Jeong, Yong Seok

    2006-02-28

    It has been suggested that defective interfering (DI) RNA contributes to the persistence of Japanese en-cephalitis virus (JEV). In this study, we characterized molecular and biological aspects of the DI RNA and its relation to viral persistence. We identified a homolo-gous DI virus intimately associated with JEV persis-tence in Vero cells. The production of DI RNA during undiluted serial passages of JEV coincided with the appearance of cells refractory to acute infection with JEV. We also established a Vero cell clone with a per-sistent JEV infection in which the DI RNA co-replicated efficiently at the expense of helper virus. The infectious virus yield of the clone fluctuated dur-ing its growth depending upon the amount of DI RNA accumulated in the previous replication cycle. Identifi-cation of the corresponding negative-sense RNA of the DI RNA indicated that the DI RNA functioned as a replication unit. Most of the DI RNA molecules re-tained their open reading frames despite a large dele-tion, encompassing most of the prM, the entire E, and the 5' half of the NS1 gene. Taken together, these ob-servations suggest that the generation of homologous DI RNA during successive JEV acute infections in Vero cells probably participates actively in persistent JEV infection. PMID:16511353

  18. Replication-competent human adenovirus 11p vectors can propagate in Vero cells.

    PubMed

    Gokumakulapalle, Madhuri; Mei, Ya-Fang

    2016-08-01

    The use of continuous cell lines derived from the African green monkey kidney (AGMK) has led to major advances in virus vaccine development. However, to date, these cells have not been used to facilitate the creation of human adenoviruses because most human adenoviruses undergo abortive infections in them. Here, we report the susceptibility of AGMK-derived cells to adenovirus 11p (Ad11p) infection. First, we showed that CD46 molecules, which act as receptors for Ad11p, are expressed in AGMK cells. We then monitored Ad11p replication by measuring GFP expression as an indicator of viral transcription. We found that AGMK-derived cells were as capable as carcinoma cells at propagating full-length replication-competent Ad11p (RCAd11p) DNA. Of the AGMK cell lines tested, Vero cells had the greatest capacity for adenovirus production. Thus, AGMK cells can be used to evaluate RCAd11p-mediated gene delivery, and Vero cells can be used for the production of RCAd11pGFP vectors at relatively high yields. PMID:27176913

  19. [A study of the antiherpetic activity of the chaga mushroom (Inonotus obliquus) extracts in the Vero cells infected with the herpes simplex virus].

    PubMed

    Polkovnikova, M V; Nosik, N N; Garaev, T M; Kondrashina, N G; Finogenova, M P; Shibnev, V A

    2014-01-01

    The chaga mushroom (Inonotus obliquus) contains a wide range of excellent bioactive compounds. However, limited information exists on the antiviral activity of the compounds extracted from chaga. A number of subfractions of chaga were obtained using different solvents and different procedures. The subfractions of chaga extracted with water, alcohol, alkali were tested for their toxicity for the Vero cell culture and antiviral effect in the Vero cells infected with the Herpes simplex virus (HSV), Type 1. It was shown that most of the subfractions were not toxic for the Vero cells and had protective effect on the Vero cells infected with HSV. The subfraction IV in the concentration 5 microg/ml protected the Vero cells from cytodestructive action of HSV and no viral DNA was detected in infected cells treated with chaga extracts. Best protective effect was observed when compound was added before or within one hour after the Vero cells were infected with HSV. PMID:25069286

  20. Prevention of lipid peroxidation induced by ochratoxin A in Vero cells in culture by several agents.

    PubMed

    Baudrimont, I; Ahouandjivo, R; Creppy, E E

    1997-04-18

    Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus as well as other moulds. This mycotoxin contaminates animal feed and food and is nephrotoxic for all animal species studied so far. OTA is immunosuppressive, genotoxic, teratogenic and carcinogenic. It is a structural analogue of phenylalanine and contains a chlorinated dihydroisocoumarinic moiety. Ochratoxin A inhibits protein synthesis by competition with phenylalanine in the phenylalanine-tRNA aminoacylation reaction. Recently lipid peroxidation induced by OTA has been reported, indicating that the lesions induced by this toxin could also be related to oxidative damage. An attempt to prevent its toxic effect, mainly the lipid peroxidation, has been made using aspartame (L-aspartyl-L-phenylalanine methyl ester) a structural analogue of both OTA and phenylalanine, piroxicam, a non steroidal anti-inflammatory drug and superoxide dismutase+catalase (endogenous oxygen radical scavengers). Lipid peroxidation was assayed in monkey kidney cells (Vero cells) treated by increasing concentrations of OTA (5-50 microM). After 24 h incubation OTA induced lipid peroxidation in Vero cells in a concentration dependent manner, as measured by malonaldehyde (MDA) production. The MDA production, in Vero cells, was significantly increased by 50.5% from 694.1 +/- 21.0 to 1041.5 +/- 23.5 pmol/mg of protein. In the presence of superoxide dismutase (SOD)+catalase (25 micrograms/ml each) the MDA production induced by OTA was significantly decreased. At 50 microM of OTA concentration (optimal production of MDA) the MDA production decreased from 1041.5 +/- 23.5 to 827.5 +/- 21.3 pmol/mg of protein. SOD and catalase, when applied prior to the toxin, seemed to prevent lipid peroxidation more efficiently than piroxicam (at a ten-fold higher concentration than OTA) and aspartame (at equimolar concentration). These molecules also partially prevented the OTA-induced leakage of MDA in the culture medium. PMID:9158693

  1. Comparative growth of spotted fever group Rickettsia spp. strains in Vero cells

    PubMed Central

    Silva, Arannadia Barbosa; Duarte, Myrian Morato; Vizzoni, Vinicius Figueiredo; Duré, Ana Íris de Lima; Lopéz, Diego Montenegro; Nogueira, Rita de Maria Seabra; Soares, Carlos Augusto Gomes; Machado-Ferreira, Erik; Gazêta, Gilberto Salles

    2016-01-01

    In Brazil, the spotted fever group (SFG) Rickettsia rickettsii and Rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. However, the SFG, Rickettsia rhipicephali, that infects humans, has never been reported. The study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. Here, the growth rates of the Brazilian isolates R. rickettsii str. Taiaçu, R. parkeri str. At#24, and R. rhipicephali HJ#5, were evaluated in Vero cells by quantitative polymerase chain reaction. R. rhipicephali showed different kinetic growth compared to R. rickettsii and R. parkeri. PMID:27508322

  2. Comparative growth of spotted fever group Rickettsia spp. strains in Vero cells.

    PubMed

    Silva, Arannadia Barbosa; Duarte, Myrian Morato; Vizzoni, Vinicius Figueiredo; Duré, Ana Íris de Lima; Lopéz, Diego Montenegro; Nogueira, Rita de Maria Seabra; Soares, Carlos Augusto Gomes; Machado-Ferreira, Erik; Gazêta, Gilberto Salles

    2016-08-01

    In Brazil, the spotted fever group (SFG) Rickettsia rickettsii and Rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. However, the SFG, Rickettsia rhipicephali, that infects humans, has never been reported. The study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. Here, the growth rates of the Brazilian isolates R. rickettsii str. Taiaçu, R. parkeri str. At#24, and R. rhipicephali HJ#5, were evaluated in Vero cells by quantitative polymerase chain reaction. R. rhipicephali showed different kinetic growth compared to R. rickettsii and R. parkeri. PMID:27508322

  3. Application of a serum-free medium for the growth of Vero cells and the production of reovirus.

    PubMed

    Butler, M; Burgener, A; Patrick, M; Berry, M; Moffatt, D; Huzel, N; Barnabé, N; Coombs, K

    2000-01-01

    Two strains of reovirus (serotype 1 Lang/TIL and serotype 3 Dearing/T3D) were propagated in Vero cells grown in stationary or agitated cultures in a serum-free medium, M-VSFM. Solid microcarriers (Cytodex-1) were used to support cell growth in agitated cultures with a normal doubling time of 25 h. Cell yields of 1 x 10(6) cells/mL were obtained from an inoculum of 2 x 10(5) cells/mL in 4 days in microcarrier cultures. The growth profile and cell yield was not significantly different from serum-supplemented cultures. The virus titer increased by 3-4 orders of magnitude over a culture period of 150 h. The maximum virus titer in stationary cultures reached >1 x 10(9) pfu/mL for both strains of reovirus in M-VSFM. M-VSFM also supported high viral yields in microcarrier cultures. Both the specific productivity and final viral yield was higher in M-VSFM than serum-supplemented cultures. The high viral productivity suggests that this is a suitable system for the production of reovirus as an oncolytic agent for human therapeutic use. PMID:11027181

  4. Avian reovirus triggers autophagy in primary chicken fibroblast cells and Vero cells to promote virus production.

    PubMed

    Meng, Songshu; Jiang, Ke; Zhang, Xiaorong; Zhang, Miao; Zhou, Zhizhi; Hu, Maozhi; Yang, Rui; Sun, Chenli; Wu, Yantao

    2012-04-01

    Avian reovirus (ARV) is an important cause of disease in poultry. Although ARV is known to induce apoptosis in infected cells, the interaction between ARV and its target cells requires further elucidation. In this report, we show that the ARV isolate strain GX/2010/1 induces autophagy in both Vero and primary chicken embryonic fibroblast (CEF) cells based on the appearance of an increased number of double-membrane vesicles, the presence of GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) dot formation, and the elevated production of LC3II. We further demonstrate that the class I phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway contributes to autophagic induction by ARV infection. Moreover, treatment of ARV-infected cells with the autophagy inducer rapamycin increased viral yields, while inhibition of the autophagosomal pathway using chloroquine led to a decrease in virus production. Altogether, our studies strongly suggest that autophagy may play a critical role in determining viral yield during ARV infection. PMID:22241622

  5. Real-time Imaging of Rabies Virus Entry into Living Vero cells

    PubMed Central

    Xu, Haijiao; Hao, Xian; Wang, Shaowen; Wang, Zhiyong; Cai, Mingjun; Jiang, Junguang; Qin, Qiwei; Zhang, Maolin; Wang, Hongda

    2015-01-01

    Understanding the mechanism of rabies virus (RABV) infection is vital for prevention and therapy of virulent rabies. However, the infection mechanism remains largely uncharacterized due to the limited methods and viral models. Herein, we utilized a powerful single-virus tracking technique to dynamically and globally visualize the infection process of the live attenuated rabies vaccine strain-SRV9 in living Vero cells. Firstly, it was found that the actin-enriched filopodia is in favor of virus reaching to the cell body. Furthermore, by carrying out drug perturbation experiments, we confirmed that RABV internalization into Vero cells proceeds via classical dynamin-dependent clathrin-mediated endocytosis with requirement for intact actin, but caveolae-dependent endocytosis is not involved. Then, our real-time imaging results unambiguously uncover the characteristics of viral internalization and cellular transport dynamics. In addition, our results directly and quantitatively reveal that the intracellular motility of internalized RABV particles is largely microtubule-dependent. Collectively, our work is crucial for understanding the initial steps of RABV infection, and elucidating the mechanisms of post-infection. Significantly, the results provide profound insight into development of novel and effective antiviral targets. PMID:26148807

  6. Real-time Imaging of Rabies Virus Entry into Living Vero cells.

    PubMed

    Xu, Haijiao; Hao, Xian; Wang, Shaowen; Wang, Zhiyong; Cai, Mingjun; Jiang, Junguang; Qin, Qiwei; Zhang, Maolin; Wang, Hongda

    2015-01-01

    Understanding the mechanism of rabies virus (RABV) infection is vital for prevention and therapy of virulent rabies. However, the infection mechanism remains largely uncharacterized due to the limited methods and viral models. Herein, we utilized a powerful single-virus tracking technique to dynamically and globally visualize the infection process of the live attenuated rabies vaccine strain-SRV9 in living Vero cells. Firstly, it was found that the actin-enriched filopodia is in favor of virus reaching to the cell body. Furthermore, by carrying out drug perturbation experiments, we confirmed that RABV internalization into Vero cells proceeds via classical dynamin-dependent clathrin-mediated endocytosis with requirement for intact actin, but caveolae-dependent endocytosis is not involved. Then, our real-time imaging results unambiguously uncover the characteristics of viral internalization and cellular transport dynamics. In addition, our results directly and quantitatively reveal that the intracellular motility of internalized RABV particles is largely microtubule-dependent. Collectively, our work is crucial for understanding the initial steps of RABV infection, and elucidating the mechanisms of post-infection. Significantly, the results provide profound insight into development of novel and effective antiviral targets. PMID:26148807

  7. Estimation of the Cultured Cells’ Volume and Surface Area: Application of Stereological Methods on Vero Cells Infected by Rubella Virus

    PubMed Central

    Noorafshan, Ali; Motamedifar, Mohammad; Karbalay-Doust, Saied

    2016-01-01

    Background: Morphological changes of the cells infected with rubella virus cannot be observed easily. Estimation of the size of the cultured cells can be a valuable parameter in this condition. This study was conducted to find answers to the following questions: How much time after infection with rubella virus, the volume and surface area of the Vero cells and their nuclei get started to change?How is it possible to apply stereological methods to estimate the volume and surface area of the cultured cells using the invariator, nucleator, and surfactor techniques? Methods: The cultured Vero cells were infected with rubella virus. The cells of the control and experimental groups were harvested at 2, 4, 8, 24, and 48 hours following the incubation period. The cells were processed and embedded in paraffin. Invariator, nucleator, and surfactor were applied to estimate the size of the Vero cells and their nuclei. Results: The cell volume was decreased by 15-24%, 48 hours after the infection in comparison to the non-infected cells. Besides, the cell surface area was decreased by 13%, 48 hours after the infection. However, no changes were detected in the nuclei. The values of the standard deviation and coefficient of variation of the cells, estimated by invariator, were lower compared to those measured by the nucleator or surfactor. Conclusion: In this study, the volume and surface area of the Vero cells were reduced by rubella virus 48 hours after infection. Invariator is a more precise method compared to nucleator or surfactor. PMID:26722143

  8. Colistin inhibits E. coli O157:H7 Shiga-like toxin release, binds endotoxins and protects Vero cells.

    PubMed

    Percivalle, Elena; Monzillo, Vincenzina; Pauletto, Alessandro; Marone, Piero; Imberti, Roberto

    2016-04-01

    The role of antibiotics in the treatment of Shiga-like toxin (Stx)-producing E. coli infection is still controversial. This study investigated the effects of colistin on Vero cell cytotoxicity caused by the enterohemorrhagic EC O157:H7, and the effects of colistin on Stx and endotoxin release by EC O157:H7. Vero cells were incubated with supernatant collected from EC O157:H7 cultured for 18 h without (control) or with various concentrations of colistin. In the absence of colistin, Vero cell viability after 48 h was 29.1±6.5%. Under the same conditions, the overnight presence of colistin reduced cytotoxicity to Vero cells (viability: 97±3.5 to 56.5±14.4% for colistin concentrations ≥MIC). Sub-MIC concentrations of colistin also provided partial protection (viability: 38.8±12.5 to 36.6±14% for 0.125 and 0.06 mcg/ml colistin, respectively). Endotoxins contributed to the cytotoxic effects on Vero cells since lower but still significant protection was observed when colistin was added directly to the supernatant collected from cultures of untreated EC O157:H7. Colistin reduced Stx release in a concentration-dependent manner, also at sub-MIC concentrations. Coincubation of the supernatant from EC O157:H7 cultures with colistin markedly reduced the endotoxin concentration at all doses investigated. In conclusion, colistin protects Vero cells from EC O157:H7 at supra- and sub-MIC concentrations by inhibiting Stx release and binding endotoxins. Colistin might be a valuable treatment for clinically severe forms of EC O157:H7 infection. PMID:27196550

  9. Adaptation of high-growth influenza H5N1 vaccine virus in Vero cells: implications for pandemic preparedness.

    PubMed

    Tseng, Yu-Fen; Hu, Alan Yung-Chih; Huang, Mei-Liang; Yeh, Wei-Zhou; Weng, Tsai-Chuan; Chen, Yu-Shuan; Chong, Pele; Lee, Min-Shi

    2011-01-01

    Current egg-based influenza vaccine production technology can't promptly meet the global demand during an influenza pandemic as shown in the 2009 H1N1 pandemic. Moreover, its manufacturing capacity would be vulnerable during pandemics caused by highly pathogenic avian influenza viruses. Therefore, vaccine production using mammalian cell technology is becoming attractive. Current influenza H5N1 vaccine strain (NIBRG-14), a reassortant virus between A/Vietnam/1194/2004 (H5N1) virus and egg-adapted high-growth A/PR/8/1934 virus, could grow efficiently in eggs and MDCK cells but not Vero cells which is the most popular cell line for manufacturing human vaccines. After serial passages and plaque purifications of the NIBRG-14 vaccine virus in Vero cells, one high-growth virus strain (Vero-15) was generated and can grow over 10(8) TCID(50)/ml. In conclusion, one high-growth H5N1 vaccine virus was generated in Vero cells, which can be used to manufacture influenza H5N1 vaccines and prepare reassortant vaccine viruses for other influenza A subtypes. PMID:22022351

  10. Chemical induction of endogenous retrovirus particles from the vero cell line of African green monkeys.

    PubMed

    Ma, Hailun; Ma, Yunkun; Ma, Wenbin; Williams, Dhanya K; Galvin, Teresa A; Khan, Arifa S

    2011-07-01

    Endogenous retroviral sequences are present in high copy numbers in the genomes of all species and may be expressed as RNAs; however, the majority are defective for virus production. Although virus has been isolated from various Old World monkey and New World monkey species, there has been no report of endogenous retroviruses produced from African green monkey (AGM) tissues or cell lines. We have recently developed a stepwise approach for evaluating the presence of latent viruses by chemical induction (Khan et al., Biologicals 37:196-201, 2009). Based upon this strategy, optimum conditions were determined for investigating the presence of inducible, endogenous retroviruses in the AGM-derived Vero cell line. Low-level reverse transcriptase activity was produced with 5-azacytidine (AzaC) and with 5'-iodo-2'-deoxyuridine (IUdR); none was detected with sodium butyrate. Nucleotide sequence analysis of PCR-amplified fragments from the gag, pol, and env regions of RNAs, prepared from ultracentrifuged pellets of filtered supernatants, indicated that endogenous retrovirus particles related to simian endogenous type D betaretrovirus (SERV) sequences and baboon endogenous virus type C gammaretrovirus (BaEV) sequences were induced by AzaC, whereas SERV sequences were also induced by IUdR. Additionally, sequence heterogeneity was seen in the RNAs of SERV- and BaEV-related particles. Infectivity analysis of drug-treated AGM Vero cells showed no virus replication in cell lines known to be susceptible to type D simian retroviruses (SRVs) and to BaEV. The results indicated that multiple, inducible endogenous retrovirus loci are present in the AGM genome that can encode noninfectious, viruslike particles. PMID:21543506

  11. Chemical Induction of Endogenous Retrovirus Particles from the Vero Cell Line of African Green Monkeys▿

    PubMed Central

    Ma, Hailun; Ma, Yunkun; Ma, Wenbin; Williams, Dhanya K.; Galvin, Teresa A.; Khan, Arifa S.

    2011-01-01

    Endogenous retroviral sequences are present in high copy numbers in the genomes of all species and may be expressed as RNAs; however, the majority are defective for virus production. Although virus has been isolated from various Old World monkey and New World monkey species, there has been no report of endogenous retroviruses produced from African green monkey (AGM) tissues or cell lines. We have recently developed a stepwise approach for evaluating the presence of latent viruses by chemical induction (Khan et al., Biologicals 37:196–201, 2009). Based upon this strategy, optimum conditions were determined for investigating the presence of inducible, endogenous retroviruses in the AGM-derived Vero cell line. Low-level reverse transcriptase activity was produced with 5-azacytidine (AzaC) and with 5′-iodo-2′-deoxyuridine (IUdR); none was detected with sodium butyrate. Nucleotide sequence analysis of PCR-amplified fragments from the gag, pol, and env regions of RNAs, prepared from ultracentrifuged pellets of filtered supernatants, indicated that endogenous retrovirus particles related to simian endogenous type D betaretrovirus (SERV) sequences and baboon endogenous virus type C gammaretrovirus (BaEV) sequences were induced by AzaC, whereas SERV sequences were also induced by IUdR. Additionally, sequence heterogeneity was seen in the RNAs of SERV- and BaEV-related particles. Infectivity analysis of drug-treated AGM Vero cells showed no virus replication in cell lines known to be susceptible to type D simian retroviruses (SRVs) and to BaEV. The results indicated that multiple, inducible endogenous retrovirus loci are present in the AGM genome that can encode noninfectious, viruslike particles. PMID:21543506

  12. A novel Vero cell line for use as a mammalian host-vector system in serum-free medium.

    PubMed

    Ohno, T; Wang, X; Kurashima, J; Saijo-Kurita, K; Hirono, M

    1991-11-01

    We have established a novel cell line from a Vero cell derivative that is useful for expression of exogenous genes and protein production. Parental Vero-317 cells can grow in biotin-containing Eagle's MEM without supplements. By transforming this cell line with replication origin-defective SV40 DNA, which contains a temperature-sensitive tsA58 large T antigen gene, we established the Verots S3 cell line that amplified a SV40-origin containing plasmid. The cell line expressed a human growth hormone (hGH) gene insert with higher efficiency than COS-7 cells in 5% serum-containing MEM and could grow and continue hGH expression in protein-free MEM. However, temperature-sensitive shut down of hGH production was observed not immediately but 3 days after the temperature shift from 33 degrees C to 39.5 degrees C. PMID:1368119

  13. Photoirradiation study of gold nanospheres and rods in Vero and Hela cell lines

    NASA Astrophysics Data System (ADS)

    Gananathan, Poorani; Aruna, Prakasarao; Ganesan, Singaravelu; Elanchezhiyan, Manickan

    2014-03-01

    Photoirradiation effect of gold nanospheres in conjucation with green light and rods in conjugation with red light corresponds to their absorption wavelength range found to be appreciable. In this present work concentration of nanomaterial and light dose were optimized. Gold nanospheres were synthesized by reduction technique using Sodium Borohydrate as reducing agent and Trisodium Citrate as capping agent. Au nanorods having 680-900nm absorption were synthesized using reduction techniques with CTAB and BDAC polymers. From UV-Vis absorption and Transmission Electron Microscopy the size of nanoparticles were confirmed. 30nm Gold nanospheres and green light source of 530nm wavelength with power 30mW were applied to Vero and Hela cell lines shows higher toxicity for Hela cells. Nanorods were applied and irradiated with 680nm wavelength light source with light intensity 45mW. Post irradiation effect for 24hrs, 48hrs confirms cell proliferation in normal rate in viable cells. The morphological changes in irradiated spot leads to apoptotoic cell death was confirmed with microscopic imaging. The LD50 value was also calculated.

  14. Development of an animal-component free medium for vero cells culture.

    PubMed

    Rourou, Samia; van der Ark, Arno; van der Velden, Tiny; Kallel, Héla

    2009-01-01

    This work describes the development of an animal-component free medium (IPT-AFM) that allows an optimal growth of Vero cells, an adherent cell line used for the production of viral vaccines. Statistical experimental design was applied to identify crucial nutrients that affect cell growth. Using Medium 199 or MEM as a basal medium, a serum-free medium (SFM) referred as IPT-SFM that only enclosed transferrin as a component of animal origin was developed at first. Then, the composition of IPT-SFM was further improved to obtain an animal-component free medium named IPT-AFM. IPT-AFM contains M199 as a basal medium, plant hydrolysates, epidermal growth factor, ethanolamine, ferric citrate, and vitamin C. Among various plant hydrolysates, specific combinations of soy (Hypep 1510) and wheat gluten (Hypeps 4601 and 4605) hydrolysates, were identified to promote cell growth; whereas individual Hypeps had a minor positive effect on cell growth. Nevertheless, the removal of serum did influence cell attachment. Coating tissue-culture flasks with teleostean, a product extracted from cold water fish skin, had not only enhanced cell attachment but also improved cell growth performance in static cultures. Different non-animal proteases were also assessed as an alternative to trypsin. TrypLE Select, a recombinant trypsin, gave the best cell growth performances. Kinetics of cell growth in IPT-AFM were investigated in T-flasks, cell growth was comparable with that obtained in MEM+10% fetal calf serum (FCS). A mean cell division number equal to 2.26 +/- 0.18 and a specific growth rate micro 0.019 +/- 0.003 h(-1) were achieved in IPT-AFM. PMID:19768803

  15. VERO cells harbor a poly-ADP-ribose belt partnering their epithelial adhesion belt

    PubMed Central

    Vilchez Larrea, Salomé C.; Kun, Alejandra

    2014-01-01

    Poly-ADP-ribose (PAR) is a polymer of up to 400 ADP-ribose units synthesized by poly-ADP-ribose-polymerases (PARPs) and degraded by poly-ADP-ribose-glycohydrolase (PARG). Nuclear PAR modulates chromatin compaction, affecting nuclear functions (gene expression, DNA repair). Diverse defined PARP cytoplasmic allocation patterns contrast with the yet still imprecise PAR distribution and still unclear functions. Based on previous evidence from other models, we hypothesized that PAR could be present in epithelial cells where cadherin-based adherens junctions are linked with the actin cytoskeleton (constituting the adhesion belt). In the present work, we have examined through immunofluorescence and confocal microscopy, the subcellular localization of PAR in an epithelial monkey kidney cell line (VERO). PAR was distinguished colocalizing with actin and vinculin in the epithelial belt, a location that has not been previously reported. Actin filaments disruption with cytochalasin D was paralleled by PAR belt disruption. Conversely, PARP inhibitors 3-aminobenzamide, PJ34 or XAV 939, affected PAR belt synthesis, actin distribution, cell shape and adhesion. Extracellular calcium chelation displayed similar effects. Our results demonstrate the existence of PAR in a novel subcellular localization. An initial interpretation of all the available evidence points towards TNKS-1 as the most probable PAR belt architect, although TNKS-2 involvement cannot be discarded. Forthcoming research will test this hypothesis as well as explore the existence of the PAR belt in other epithelial cells and deepen into its functional implications. PMID:25332845

  16. Generation of Recombinant Arenavirus for Vaccine Development in FDA-Approved Vero Cells

    PubMed Central

    de la Torre, Juan Carlos; Martínez-Sobrido, Luis

    2013-01-01

    The development and implementation of arenavirus reverse genetics represents a significant breakthrough in the arenavirus field 4. The use of cell-based arenavirus minigenome systems together with the ability to generate recombinant infectious arenaviruses with predetermined mutations in their genomes has facilitated the investigation of the contribution of viral determinants to the different steps of the arenavirus life cycle, as well as virus-host interactions and mechanisms of arenavirus pathogenesis 1, 3, 11 . In addition, the development of trisegmented arenaviruses has permitted the use of the arenavirus genome to express additional foreign genes of interest, thus opening the possibility of arenavirus-based vaccine vector applications 5 . Likewise, the development of single-cycle infectious arenaviruses capable of expressing reporter genes provides a new experimental tool to improve the safety of research involving highly pathogenic human arenaviruses 16 . The generation of recombinant arenaviruses using plasmid-based reverse genetics techniques has so far relied on the use of rodent cell lines 7,19 , which poses some barriers for the development of Food and Drug Administration (FDA)-licensed vaccine or vaccine vectors. To overcome this obstacle, we describe here the efficient generation of recombinant arenaviruses in FDA-approved Vero cells. PMID:23928556

  17. Production in Vero cells of an inactivated rabies vaccine from strain FRV/K for animal and human use.

    PubMed

    el-Karamany, R M

    1987-08-01

    A new concentrated and purified rabies vaccine was produced in Vero cells. Two rabies virus strains, the fixed rabies virus Pasteur (FRV) and Pittman Moore (PM) were adapted to Vero cells by 20 cycles of alternating passages in the brain of weaning mice. Intracerebral (i.c.) inoculation of weaning mice was followed then by 17 and 20 serial passages in Vero cells of RFV and PM strains, respectively. The adapted strains designated as FRV/K and PM/K gave titres of 10(6) +/- 1.5 log (LD50/ml for i.c. inoculated mice) in several harvests taken from one infected cell culture. Pooled harvests were concentrated 20-fold by ultrafiltration and were tested as animal vaccine after inactivation with beta-propiolactone (BPL). Another vaccine preparation destined for human use, in addition to concentration and inactivation, was also purified by gel filtration. Control tests revealed that the antigenic content of different strain FRV/K harvests was very high in comparison with that of strain PM/K and the reference tissue culture vaccine (RIV, Netherland). In sheep the antibody response induced by the FRV/K strain was very high; serum neutralizing index (NI) higher than 4 was reached 40 days after the second vaccine dose, whereas the vaccine preparation from strain PM/K gave NI of 2.3 and the reference vaccine NI of 3.8, respectively. Safety tests in rabbits and guinea pigs showed neither pyrogenicity nor toxicity. PMID:2892381

  18. VeroNectin-4 is a highly sensitive cell line that can be used for the isolation and titration of Peste des Petits Ruminants virus.

    PubMed

    Fakri, F; Elarkam, A; Daouam, S; Tadlaoui, K; Fassi-Fihri, O; Richardson, C D; Elharrak, M

    2016-02-01

    Peste des Petits Ruminants virus (PPRV) is a member of the Morbillivirus subgroup of the family Paramyxoviridae, and is one of the most contagious diseases of small ruminants throughout Africa and the rest of the world. Different cell lines have previously been used to isolate PPRV but with limited success. Thus, to improve the isolation of Morbilliviruses, human, canine, and goat homologues of the lymphocyte receptor signaling lymphocyte activation molecule (SLAM) have been introduced into cells that can support virus replication. However, the amino acid sequence of SLAM varies between species, and often requires adaptation of a particular virus to different versions of the receptor. The protein sequence of Nectin-4 is highly conserved between different mammals, which eliminate the need for receptor adaptation by the virus. Cell lines expressing Nectin-4 have previously been used to propagate measles and canine distemper viruses. In this study, we compared infections in Vero cells expressing canine SLAM (VeroDogSLAM) to those in Vero cells expressing Nectin-4 (VeroNectin-4), following inoculations with wild-type strains of PPRV. Virus isolation using VeroNectin-4 cells was successful with 23% of swabbed samples obtained from live infected animals, and was 89% effective using post-mortem tissues of infected sheep. By contrast, only 4.5% efficiency was observed from swab samples and 67% efficiency was obtained in virus isolation from post-mortem tissues using VeroDogSLAM cells. The average incubation period for virus recovery from post-mortem tissues was 3.4 days using VeroNectin-4 cells, compared with 5.5 days when using VeroDogSLAM cells. The virus titers of PPRV obtained from VeroNectin-4 cells were also higher than those derived from VeroDogSLAM cells. A comparison of the growth kinetics for PPRV in the two cell lines confirmed the superiority of VeroNectin-4 cells for PPR diagnostic purposes and vaccine virus titration. PMID:26615804

  19. An inactivated yellow fever 17DD vaccine cultivated in Vero cell cultures.

    PubMed

    Pereira, Renata C; Silva, Andrea N M R; Souza, Marta Cristina O; Silva, Marlon V; Neves, Patrícia P C C; Silva, Andrea A M V; Matos, Denise D C S; Herrera, Miguel A O; Yamamura, Anna M Y; Freire, Marcos S; Gaspar, Luciane P; Caride, Elena

    2015-08-20

    Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious public health problem causing epidemics of hemorrhagic fever with mortality rates ranging from 20% to 50%. There is no available antiviral therapy and vaccination is the primary method of disease control. Although the attenuated vaccines for yellow fever show safety and efficacy it became necessary to develop a new yellow fever vaccine due to the occurrence of rare serious adverse events, which include visceral and neurotropic diseases. The new inactivated vaccine should be safer and effective as the existing attenuated one. In the present study, the immunogenicity of an inactivated 17DD vaccine in C57BL/6 mice was evaluated. The yellow fever virus was produced by cultivation of Vero cells in bioreactors, inactivated with β-propiolactone, and adsorbed to aluminum hydroxide (alum). Mice were inoculated with inactivated 17DD vaccine containing alum adjuvant and followed by intracerebral challenge with 17DD virus. The results showed that animals receiving 3 doses of the inactivated vaccine (2 μg/dose) with alum adjuvant had neutralizing antibody titers above the cut-off of PRNT50 (Plaque Reduction Neutralization Test). In addition, animals immunized with inactivated vaccine showed survival rate of 100% after the challenge as well as animals immunized with commercial attenuated 17DD vaccine. PMID:25862300

  20. Apoptotic activity and anti-Toxoplasma effects of artemether on the tachyzoites and experimental infected Vero and J774 cell lines by Toxoplasma gondii

    PubMed Central

    Mikaeiloo, Hajar; Ghaffarifar, Fatemeh; Dalimi, Abdolhossein; Sharifi, Zohreh; Hassan, Zuhair Mohammad

    2016-01-01

    Objectives: Drugs used for toxoplasmosis have limited efficacy and also severe side effects. A new drug with good efficacy and limited side effects is need of the hour. We studied the effects of artemether on Toxoplasma gondii in vitro conditions. Materials and Methods: Artemether (methyl-ether-qinghaosu) was tested for tachyzoites, J774, and Vero cell lines infected by T. gondii. For evaluating the effect of drugs on Vero cells infected with T. gondii, we designed two separate experiments; in the first experiment, the Vero cells were infected with tachyzoites and then treated with artemether; while in the second one, the tachyzoites were exposed to artemether and then Vero cells were infected with treated tachyzoites. For evaluating the apoptotic effect of artemether on tachyzoites and infected J774 macrophages cell line with T. gondii, we used flow cytometry method. Inhibitory concentration (IC50) was evaluated by intracellular replication of tachyzoites in Vero cells. Results: IC50 for infected Vero cells with tachyzoites was determined as 49.13 μg/ml. In pretreated tachyzoites with artemether before entering into Vero cells, IC50 was calculated as 13.15 μg/ml. In both experiments, artemether showed a higher inhibitory effect than sulfadiazine (positive control). Artemether even at the highest concentrations only showed low cytotoxicity on Vero and J774 cell lines. Apoptosis in tachyzoites rise with an increasing concentration of artemether. Conclusions: Our findings indicate that artemether is effective to control the tachyzoites of T. gondii in vitro and maybe a good alternative drug for toxoplasmosis. PMID:27127321

  1. Comparison of herpes simplex (HSV) proteins synthesized in Vero, HEP-2 and human megakaryocyte-like cell lines

    SciTech Connect

    Soslau, G.; Pastorino, M.B.; Morgan, D.A.; Brodsky, I.; Howett, M.K.

    1986-05-01

    The natural human host blood cell capable of supporting herpes virus replication has yet to be defined. They found that a recently cultured human megakaryocyte-like (Meg) cell line can support HSV 1 and 2 replication as demonstrated by growth inhibition, CPE, virus production and HSV DNA synthesis. The HSV proteins synthesized and post-translationally modified in Vero and HEp-2 infected cells were compared to the protein species produced in the infected Meg cell since differences may influence antigenic properties and host range. Host cell protein synthesis was greatly reduced in all three cell lines within hours post infection (pi). However, maximum viral protein synthesis occurs between 4 and 24 hrs pi with the Meg cells as compared to 24-48 hrs pi with the other cell lines. The immunoprecipitated /sup 35/S-methionine labeled HSV protein gel patterns for each infected cell line are qualitatively and quantitatively very different from each other. Dramatic differences were also observed when infected cells were labeled with /sup 32/P-ATP (in vitro method) or /sup 32/Pi (in vivo method). Finally, analysis of /sup 3/H-mannose labeled HSV glycoproteins demonstrates that the post-translational modifications of these proteins are significantly altered in the Meg cell as compared to the Vero and HEp-2 cells.

  2. Cell culture (Vero) derived whole virus (H5N1) vaccine based on wild-type virus strain induces cross-protective immune responses

    PubMed Central

    Kistner, Otfried; Howard, Keith; Spruth, Martin; Wodal, Walter; Brühl, Peter; Gerencer, Marijan; Crowe, Brian A.; Savidis-Dacho, Helga; Livey, Ian; Reiter, Manfred; Mayerhofer, Ines; Tauer, Christa; Grillberger, Leopold; Mundt, Wolfgang; Falkner, Falko G.; Barrett, P. Noel

    2007-01-01

    The rapid spread and the transmission to humans of avian influenza virus (H5N1) has induced world-wide fears of a new pandemic and raised concerns over the ability of standard influenza vaccine production methods to rapidly supply sufficient amounts of an effective vaccine. We report here on a robust and flexible strategy which uses wild-type virus grown in a continuous cell culture (Vero) system to produce an inactivated whole virus vaccine. Candidate vaccines based on clade 1 and clade 2 influenza H5N1 strains were developed and demonstrated to be highly immunogenic in animal models. The vaccines induce cross-neutralising antibodies, highly cross-reactive T-cell responses and are protective in a mouse challenge model not only against the homologous virus but against other H5N1 strains, including those from another clade. These data indicate that cell culture-grown, whole virus vaccines, based on the wild-type virus, allow the rapid high yield production of a candidate pandemic vaccine. PMID:17614165

  3. Dengue-3 Virus Entry into Vero Cells: Role of Clathrin-Mediated Endocytosis in the Outcome of Infection

    PubMed Central

    Piccini, Luana E.; Castilla, Viviana; Damonte, Elsa B.

    2015-01-01

    The endocytic uptake and intracellular trafficking for penetration of DENV-3 strain H-87 into Vero cells was analyzed by using several biochemical inhibitors and dominant negative mutants of cellular proteins. The results presented show that the infective entry of DENV-3 into Vero cells occurs through a non-classical endocytosis pathway dependent on low pH and dynamin, but non-mediated by clathrin. After uptake, DENV-3 transits through early endosomes to reach Rab 7-regulated late endosomes, and according with the half-time for ammonium chloride resistance viral nucleocapsid is released into the cytosol approximately at 12 min post-infection. Furthermore, the influence of the clathrin pathway in DENV-3 infective entry in other mammalian cell lines of human origin, such as A549, HepG2 and U937 cells, was evaluated demonstrating that variable entry pathways are employed depending on the host cell. Results show for the first time the simultaneous coexistence of infective and non -infective routes for DENV entry into the host cell, depending on the usage of clathrin-mediated endocytosis. PMID:26469784

  4. Safety and immunogenicity of two freeze-dried Vero cell rabies vaccines for human use in post-exposure prophylaxis.

    PubMed

    Wang, Ling-yun; Sun, Mei-ping; Zhang, Xue-chun; Suo, Luo-dan; Xu, Ruo-hui; Zou, Yan-jie; Zuo, Li-bo; Qi, Hua

    2011-03-24

    To provide basis for human rabies vaccination in China, the safety and immunogenicity of two freeze-dried Vero cell rabies vaccines for human use were assessed. A total of 250 volunteers were enrolled and divided into two groups: volunteers in Group A (n=200) were vaccinated five doses of Speeda Vero cell rabies vaccine manufactured by Liaoning Chengda Biotechnology Co. Ltd. on day 0, 3, 7, 14, 28 after exposure. Volunteers in Group B (n=50) were treated with Verorab Vero cell rabies vaccine manufactured by Sanofi Pasteur on the same schedule. The local and systematic adverse reactions were observed. Serum neutralizing antibody levels of 80 individuals in Group A and 50 individuals in Group B were tested with RFFIT on day 7, 14, 45, 180, 360 after the first dose. The seroconversion rates in Groups A and B were 40.3% and 37.0% on day 7 after the first dose, 95.5% and 97.7% on day 14, 100% and 100% on day 45, 100% and 100% on day 180, 89.1% and 89.5% on day 360 respectively, indicating no significant differences between the two groups. And no significant differences were found between the neutralizing antibody geometric mean titers (GMTs) of the two groups on day 7, 14, 45, 180 and 360 after the first dose, with the GMTs of day 14, 45, 180 and 360 all higher than 0.5IU/ml. Antibody levels of the two groups peaked around 2 weeks after the full vaccination program, followed by a 55% decrease up to day 180 and another 76% decrease up to day 360. Both groups experienced occasions of transient fever, rash, edema, and scleroma after vaccination. Neither group had any severe adverse reactions. It was concluded that both vaccines showed satisfactory safety and immunogenicity. Booster vaccination is recommended following another exposure after six months since the full vaccination program. PMID:21296694

  5. Absolute quantification of dengue virus serotype 4 chimera vaccine candidate in Vero cell culture by targeted mass spectrometry.

    PubMed

    Rougemont, Blandine; Simon, Romain; Carrière, Romain; Biarc, Jordane; Fonbonne, Catherine; Salvador, Arnaud; Huillet, Céline; Berard, Yves; Adam, Olivier; Manin, Catherine; Lemoine, Jérôme

    2015-10-01

    Infection by dengue flavivirus is transmitted by mosquitoes and affects tens to hundreds of millions people around the world each year. Four serotypes have been described, all of which cause similar disease. Currently, there no approved vaccines or specific therapeutics for dengue, although several vaccine prototypes are in different stages of clinical development. Among them, a chimeric vaccine, built from the replication machinery of the yellow fever 17D virus, has shown promising results in phase III trials. Accurate quantitation of expressed viral particles in alive attenuated viral antigen vaccine is essential and determination of infectious titer is usually the method of choice. The current paper describes an alternative or orthogonal strategy, namely, a multiplexed and absolute assay of four proteins of the chimera yellow fever/dengue serotype 4 virus using targeted MS in SRM mode. Over 1 month, variability of the assay using a partially purified Vero cell extract was between 8 and 17%, and accuracy was between 80 and 120%. In addition, the assay was linear between 6.25 and 200 nmol/L and could therefore be used in the near future to quantify dengue virus type 4 during production and purification from Vero cells. PMID:26205729

  6. Chemical Synthesis, Characterisation, and Biocompatibility of Nanometre Scale Porous Anodic Aluminium Oxide Membranes for Use as a Cell Culture Substrate for the Vero Cell Line: A Preliminary Study

    PubMed Central

    Poinern, Gérrard Eddy Jai; Le, Xuan Thi; Becker, Thomas; Fawcett, Derek

    2014-01-01

    In this preliminary study we investigate for the first time the biomedical potential of using porous anodic aluminium oxide (AAO) membranes as a cell substrate for culturing the Cercopithecus aethiops (African green monkey) Kidney (Vero) epithelial cell line. One advantage of using the inorganic AAO membrane is the presence of nanometre scale pore channels that allow the exchange of molecules and nutrients across the membrane. The size of the pore channels can be preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The cellular interaction and response of the Vero cell line with an in-house synthesised AAO membrane, a commercially available membrane, and a glass control were assessed by investigating cell adhesion, morphology, and proliferation over a 72 h period. The number of viable cells proliferating over the respective membrane surfaces revealed that the locally produced in-house AAO membrane had cells numbers similar to the glass control. The study revealed evidence of focal adhesion sites over the surface of the nanoporous membranes and the penetration of cellular extensions into the pore structure as well. The outcome of the study has revealed that nanometre scale porous AAO membranes have the potential to become practical cell culture scaffold substrates with the capability to enhance adhesion and proliferation of Vero cells. PMID:24579077

  7. Chemical synthesis, characterisation, and biocompatibility of nanometre scale porous anodic aluminium oxide membranes for use as a cell culture substrate for the vero cell line: a preliminary study.

    PubMed

    Poinern, Gérrard Eddy Jai; Le, Xuan Thi; O'Dea, Mark; Becker, Thomas; Fawcett, Derek

    2014-01-01

    In this preliminary study we investigate for the first time the biomedical potential of using porous anodic aluminium oxide (AAO) membranes as a cell substrate for culturing the Cercopithecus aethiops (African green monkey) Kidney (Vero) epithelial cell line. One advantage of using the inorganic AAO membrane is the presence of nanometre scale pore channels that allow the exchange of molecules and nutrients across the membrane. The size of the pore channels can be preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The cellular interaction and response of the Vero cell line with an in-house synthesised AAO membrane, a commercially available membrane, and a glass control were assessed by investigating cell adhesion, morphology, and proliferation over a 72 h period. The number of viable cells proliferating over the respective membrane surfaces revealed that the locally produced in-house AAO membrane had cells numbers similar to the glass control. The study revealed evidence of focal adhesion sites over the surface of the nanoporous membranes and the penetration of cellular extensions into the pore structure as well. The outcome of the study has revealed that nanometre scale porous AAO membranes have the potential to become practical cell culture scaffold substrates with the capability to enhance adhesion and proliferation of Vero cells. PMID:24579077

  8. Dengue Type 4 Live-Attenuated Vaccine Viruses Passaged in Vero Cells Affect Genetic Stability and Dengue-Induced Hemorrhaging in Mice

    PubMed Central

    Lee, Hsiang-Chi; Yen, Yu-Ting; Chen, Wen-Yu; Wu-Hsieh, Betty A.; Wu, Suh-Chin

    2011-01-01

    Most live-attenuated tetravalent dengue virus vaccines in current clinical trials are produced from Vero cells. In a previous study we demonstrated that an infectious cDNA clone-derived dengue type 4 (DEN-4) virus retains higher genetic stability in MRC-5 cells than in Vero cells. For this study we investigated two DEN-4 viruses: the infectious cDNA clone-derived DEN-4 2A and its derived 3′ NCR 30-nucleotide deletion mutant DEN-4 2AΔ30, a vaccine candidate. Mutations in the C-prM-E, NS2B-NS3, and NS4B-NS5 regions of the DEN genome were sequenced and compared following cell passages in Vero and MRC-5 cells. Our results indicate stronger genetic stability in both viruses following MRC-5 cell passages, leading to significantly lower RNA polymerase error rates when the DEN-4 virus is used for genome replication. Although no significant increases in virus titers were observed following cell passages, DEN-4 2A and DEN-4 2AΔ30 virus titers following Vero cell passages were 17-fold to 25-fold higher than titers following MRC-5 cell passages. Neurovirulence for DEN-4 2A and DEN-4 2AΔ30 viruses increased significantly following passages in Vero cells compared to passages in MRC-5 cells. In addition, more severe DEN-induced hemorrhaging in mice was noted following DEN-4 2A and DEN-4 2AΔ30 passages in Vero cells compared to passages in MRC-5 cells. Target mutagenesis performed on the DEN-4 2A infectious clone indicated that single point mutation of E-Q438H, E-V463L, NS2B-Q78H, and NS2B-A113T imperatively increased mouse hemorrhaging severity. The relationship between amino acid mutations acquired during Vero cell passage and enhanced DEN-induced hemorrhages in mice may be important for understanding DHF pathogenesis, as well as for the development of live-attenuated dengue vaccines. Taken together, the genetic stability, virus yield, and DEN-induced hemorrhaging all require further investigation in the context of live-attenuated DEN vaccine development. PMID:22053180

  9. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    SciTech Connect

    Roehrig, John T.; Butrapet, Siritorn; Liss, Nathan M.; Bennett, Susan L.; Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E.; Blair, Carol D.; Huang, Claire Y.-H.

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  10. Isolation of measles virus from clinical specimens using B95a and Vero/hSLAM cell-lines.

    PubMed

    Keniscope, C; Juliana, R; Subri, H; Shangari, S R; Wan Nor Azlina, W A; Hamizah, A; Emmi, E E; Nor Azlina, M D; Norizah, I; Chua, K B

    2009-03-01

    The clinical presentation of acute measles is normally quite typical, especially in the presence of Koplik's spots, that laboratory test is seldom required to confirm the diagnosis. However, with wide measles vaccination coverage and the extensive use of immunosuppressive chemotherapy, the diagnosis of atypical manifestations of acute measles may require laboratory confirmation. When compared with B95a cell-line, this study shows that the Vero/hSLAM cell-line is sensitive and is recommended for use in the primary isolation of wild-type measles virus from clinical specimens. Throat swab and urine specimens are the clinical specimens of choice and both are recommended for optimal isolation of measles virus from patients suspected of acute measles virus infection. PMID:19852319

  11. Toxicity and Antiviral Activity of the Extracts of Submerged Mycelium of Nematophagous Duddingtonia flagrans Fungus in Vero Cell Culture.

    PubMed

    Ibragimova, Zh B; Anan'ko, G G; Kostina, N E; Teplyakova, T V; Mazurkova, N A

    2015-12-01

    We studied toxicity and antiviral activity of aqueous and ethanol extracts of bioactive substances from the biomass of nematophagous fungus Duddingtonia flagrans prepared by submerged culturing of the mycelium. It is found that both extracts were characterized by low toxicity for cultured Vero cells and inhibited reproduction of DNA-viruses in this cell line. Ethanol extract of the fungus exhibited higher in vitro antiviral activity against Herpes simplex virus type 2, ectromelia virus, and vaccinia virus than water extract, which can be due to higher content of proteins, polysaccharides, flavonols, catechins, or carotenes or more effective their combination. The extracts of cultured mycelium of Duddingtonia flagrans fungus containing a complex of bioactive substances can be used for creation of broad-spectrum antiviral drugs against DNA-viruses. PMID:26621278

  12. Non-linear relationships between aflatoxin B₁ levels and the biological response of monkey kidney vero cells.

    PubMed

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2013-08-01

    Aflatoxin-producing fungi contaminate food and feed during pre-harvest, storage and processing periods. Once consumed, aflatoxins (AFs) accumulate in tissues, causing illnesses in animals and humans. Most human exposure to AF seems to be a result of consumption of contaminated plant and animal products. The policy of blending and dilution of grain containing higher levels of aflatoxins with uncontaminated grains for use in animal feed implicitly assumes that the deleterious effects of low levels of the toxins are linearly correlated to concentration. This assumption may not be justified, since it involves extrapolation of these nontoxic levels in feed, which are not of further concern. To develop a better understanding of the significance of low dose effects, in the present study, we developed quantitative methods for the detection of biologically active aflatoxin B₁ (AFB1) in Vero cells by two independent assays: the green fluorescent protein (GFP) assay, as a measure of protein synthesis by the cells, and the microculture tetrazolium (MTT) assay, as a measure of cell viability. The results demonstrate a non-linear dose-response relationship at the cellular level. AFB1 at low concentrations has an opposite biological effect to higher doses that inhibit protein synthesis. Additional studies showed that heat does not affect the stability of AFB1 in milk and that the Vero cell model can be used to determine the presence of bioactive AFB1 in spiked beef, lamb and turkey meat. The implication of the results for the cumulative effects of low amounts of AFB1 in numerous foods is discussed. PMID:23949006

  13. Non-Linear Relationships between Aflatoxin B1 Levels and the Biological Response of Monkey Kidney Vero Cells

    PubMed Central

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2013-01-01

    Aflatoxin-producing fungi contaminate food and feed during pre-harvest, storage and processing periods. Once consumed, aflatoxins (AFs) accumulate in tissues, causing illnesses in animals and humans. Most human exposure to AF seems to be a result of consumption of contaminated plant and animal products. The policy of blending and dilution of grain containing higher levels of aflatoxins with uncontaminated grains for use in animal feed implicitly assumes that the deleterious effects of low levels of the toxins are linearly correlated to concentration. This assumption may not be justified, since it involves extrapolation of these nontoxic levels in feed, which are not of further concern. To develop a better understanding of the significance of low dose effects, in the present study, we developed quantitative methods for the detection of biologically active aflatoxin B1 (AFB1) in Vero cells by two independent assays: the green fluorescent protein (GFP) assay, as a measure of protein synthesis by the cells, and the microculture tetrazolium (MTT) assay, as a measure of cell viability. The results demonstrate a non-linear dose-response relationship at the cellular level. AFB1 at low concentrations has an opposite biological effect to higher doses that inhibit protein synthesis. Additional studies showed that heat does not affect the stability of AFB1 in milk and that the Vero cell model can be used to determine the presence of bioactive AFB1 in spiked beef, lamb and turkey meat. The implication of the results for the cumulative effects of low amounts of AFB1 in numerous foods is discussed. PMID:23949006

  14. High-yield production of a stable Vero cell-based vaccine candidate against the highly pathogenic avian influenza virus H5N1

    SciTech Connect

    Zhou, Fangye; Zhou, Jian; Ma, Lei; Song, Shaohui; Zhang, Xinwen; Li, Weidong; Jiang, Shude; Wang, Yue; Liao, Guoyang

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Vero cell-based HPAI H5N1 vaccine with stable high yield. Black-Right-Pointing-Pointer Stable high yield derived from the YNVa H3N2 backbone. Black-Right-Pointing-Pointer H5N1/YNVa has a similar safety and immunogenicity to H5N1delta. -- Abstract: Highly pathogenic avian influenza (HPAI) viruses pose a global pandemic threat, for which rapid large-scale vaccine production technology is critical for prevention and control. Because chickens are highly susceptible to HPAI viruses, the supply of chicken embryos for vaccine production might be depleted during a virus outbreak. Therefore, developing HPAI virus vaccines using other technologies is critical. Meeting vaccine demand using the Vero cell-based fermentation process has been hindered by low stability and yield. In this study, a Vero cell-based HPAI H5N1 vaccine candidate (H5N1/YNVa) with stable high yield was achieved by reassortment of the Vero-adapted (Va) high growth A/Yunnan/1/2005(H3N2) (YNVa) virus with the A/Anhui/1/2005(H5N1) attenuated influenza vaccine strain (H5N1delta) using the 6/2 method. The reassorted H5N1/YNVa vaccine maintained a high hemagglutination (HA) titer of 1024. Furthermore, H5N1/YNVa displayed low pathogenicity and uniform immunogenicity compared to that of the parent virus.

  15. Characterization of Vero cell growth and death in bioreactor with serum-containing and serum-free media.

    PubMed

    Quesney, S; Marvel, J; Marc, A; Gerdil, C; Meignier, B

    2001-03-01

    The density of viable cells in a culture results from a balance between cell proliferation and cell death. The aim of this study was to characterize and compare these two phenomena in Vero cell cultures in one serum containing medium (ScA) and one serum free medium (SfB) in bioreactors. Cell growth was evaluated by cell counting(after crystal violet staining) and cell cycle analysis. Necrosis and apoptosis were characterized and quantified by measuring the release of LDH, trypan blue exclusion,annex in V-FITC/PI staining and TUNEL assay. ScA supported a higher maximal viable-cell density(2.3 x 10(6) vs. 1.8 x 10(6) cells ml(-1)). However, cell cycle analysis showed that cell division was more active in SfB than in ScA. LDH release in the supernatant increased much earlier in SfB than in ScA (one vs. five days), but trypan blue counts showed no apparent difference in the viability of the cultures. Apoptosis, evidenced by annexin V-FITC/PI staining, could be detected in the population of suspension cells detached from microcarriers, but not among adherent cells; positivity of the TUNEL assay occurred later than that of the annexin V-FITC/PI staining. Our data indicate that the lower cell yield in SfB,compared with that in ScA, results from a higher cell death rate. Apparently, cells die from apoptosis followed by secondary necrosis. PMID:19003288

  16. Photodynamic efficiency of hypericin compared with chlorin and hematoporphyrin derivatives in HEp-2 and Vero epithelial cell lines.

    PubMed

    Bernal, Claudia; Ribeiro, Anderson O; Andrade, Gislaine P; Perussi, Janice R

    2015-06-01

    Hypericin (HY) is a photoactive aromatic dianthraquinone that is considered a potent photodynamic agent. In this study, hypericin and two other photosensitizers, a hematoporphyrin derivative (Photogem(®); PG) and a chlorin derivative (Photodithazine(®); PZ), were compared in terms of their phototoxicity toward two cell lines, HEp-2 and Vero. The median inhibitory concentration (IC(50)) of each of the photosensitizers was obtained after a 16.2J cm(-2) dose of irradiation at 630 ± 10 nm. The IC(50) values were 0.07 ± 0.01 (HY), 1.0 ± 0.2 (PZ), and 9 ± 1 μgmL(-1) (PG) in HEp-2 cells and 0.3 ± 0.1 (HY), 1.6 ± 0.2 (PZ) and 11 ± 1 μgmL(-1) (PG) in Vero cells, showing that HY is more phototoxic than the others when irradiated at 630 nm. If these results are analyzed, simultaneously, with the first-order constant for BSA tryptophan photooxidation, obtained by fluorescence decay (λ(excitation)=280 nm), which are 11×10(-3) min(-1)±1. 10(-3) min(-1) (HY), 10 × 10(-3) min(-1)±1 × 10(-3) min(-1) (PZ), and 6 × 10(-3)min(-1) ± 1×10(-3)min(-1) (PG), it is possible to infer that the photodynamic efficiency alone is not sufficient to explain the higher HY phototoxicity. The lipophilicity is also an important factor for an efficient target cell accumulation and was assessed for all sensitizers through the octanol-water partition coefficient (log P): 1.20 ± 0.02 (HY), -0.62 ± 0.03 (PZ), and -0.9 ± 0.2 (PG). The higher value for HY correlates well with its observed superior efficiency to promote damage at low concentrations and doses. As HY is used for the long-term treatment of mild depression, it is considered safe for humans. This fact and the present results reinforce the great potential of this photosensitizer to replace porphyrin derivatives, with the advantages that mean it could be used as photosensitizer in clinical photodynamic therapy. PMID:25910552

  17. A polysaccharide fraction from medicinal herb Prunella vulgaris downregulates the expression of herpes simplex virus antigen in Vero cells.

    PubMed

    Chiu, Lawrence Chi-Ming; Zhu, Wen; Ooi, Vincent Eng-Choon

    2004-07-01

    Herpes simplex viruses (HSV) are pathogenic. With the emergence of drug-resistant strains of HSV, new antiviral agents, especially those with different modes of action, are urgently needed. Prunella vulgaris L. (Labiatae), a perennial plant commonly found in China and Europe, has long been used as a folk medicine to cure ailments. In this study, a polysaccharide fraction was prepared from Prunella vulgaris (PPV), and its effects on the expressions of HSV-1 and HSV-2 antigens in their host Vero cells were investigated with flow cytometry. The HSV antigen increased time-dependently in the infected cells, and PPV reduced its expression. The effective concentrations of PPV with 50% reductions of the HSV-1 and HSV-2 antigens were 20.6 and 20.1 microg/ml, respectively. The novelty of PPV is that it also reduces the antigen expression of acyclovir-resistant strain of HSV-1. After incubations with 25-100 microg/ml of PPV the HSV antigen-positive cells were reduced by 24.8-92.6%, respectively, showing that this polysaccharide fraction has a different mode of anti-HSV action from acyclovir. Results from this study show that PPV is effective against both the HSV-1 and HSV-2 infections, and flow cytometry offers a quantitative and highly reproducible anti-HSV drug-susceptibility assay. PMID:15182906

  18. A basic study on the biological monitoring for vanadium-effects of vanadium on Vero cells and the evaluation of intracellular vanadium contents.

    PubMed

    Mochizuki, Mariko; Kudo, Eiko; Kikuchi, Mitsuho; Takano, Takashi; Taniuchi, Yojiro; Kitamura, Tomoya; Hondo, Ryo; Ueda, Fukiko

    2011-07-01

    A high concentration of vanadium (V) has toxic effects on human and animals and is one of environmental pollutants. In the present study, we have conducted a fundamental study using cultured Vero cells from monkey kidney for the future environmental monitoring. Orthovanadate (VAN), one of V compounds, of 10(-10) and 10(-8) M did not affect the cell growth although the higher concentration of above 10(-6) M VAN inhibited the cell growth accompanied with the decrease in cell numbers and morphological changes. Given that the washing method with ice-cold Li is also effective for determination of the cellular Na content, we used this method for the determination of the V content of the Vero cells. The V distributions in Vero cell; in the 10(-3) M VAN solution, extracellular and intracellular were obtained as 1:0.564:0.036 and 1:0.662:0.098 at 60 and 120 min after the treatment of VAN. The intracellular V content was 10% of the applied concentration of VAN. Consequently, it was suggested that V concentration of 10(-7) and 10(-6) M in the tissue and environment, respectively, might become the threshold concentration; a criterion of the environmental contamination when we carry out environmental monitoring. PMID:20556539

  19. Detection of Vero Cells Infected with Herpes Simplex Types 1 and 2 and Varicella Zoster Viruses Using Raman Spectroscopy and Advanced Statistical Methods

    PubMed Central

    Huleihel, Mahmoud; Shufan, Elad; Zeiri, Leila; Salman, Ahmad

    2016-01-01

    Of the eight members of the herpes family of viruses, HSV1, HSV2, and varicella zoster are the most common and are mainly involved in cutaneous disorders. These viruses usually are not life-threatening, but in some cases they might cause serious infections to the eyes and the brain that can lead to blindness and possibly death. An effective drug (acyclovir and its derivatives) is available against these viruses. Therefore, early detection and identification of these viral infections is highly important for an effective treatment. Raman spectroscopy, which has been widely used in the past years in medicine and biology, was used as a powerful spectroscopic tool for the detection and identification of these viral infections in cell culture, due to its sensitivity, rapidity and reliability. Our results showed that it was possible to differentiate, with a 97% identification success rate, the uninfected Vero cells that served as a control, from the Vero cells that were infected with HSV-1, HSV-2, and VZV. For that, linear discriminant analysis (LDA) was performed on the Raman spectra after principal component analysis (PCA) with a leave one out (LOO) approach. Raman spectroscopy in tandem with PCA and LDA enable to differentiate among the different herpes viral infections of Vero cells in time span of few minutes with high accuracy rate. Understanding cell molecular changes due to herpes viral infections using Raman spectroscopy may help in early detection and effective treatment. PMID:27078266

  20. Nonreplicating Vaccinia Virus Vectors Expressing the H5 Influenza Virus Hemagglutinin Produced in Modified Vero Cells Induce Robust Protection▿

    PubMed Central

    Mayrhofer, Josef; Coulibaly, Sogue; Hessel, Annett; Holzer, Georg W.; Schwendinger, Michael; Brühl, Peter; Gerencer, Marijan; Crowe, Brian A.; Shuo, Shen; Hong, Wanjing; Tan, Yee Joo; Dietrich, Barbara; Sabarth, Nicolas; Savidis-Dacho, Helga; Kistner, Otfried; Barrett, P. Noel; Falkner, Falko G.

    2009-01-01

    The timely development of safe and effective vaccines against avian influenza virus of the H5N1 subtype will be of the utmost importance in the event of a pandemic. Our aim was first to develop a safe live vaccine which induces both humoral and cell-mediated immune responses against human H5N1 influenza viruses and second, since the supply of embryonated eggs for traditional influenza vaccine production may be endangered in a pandemic, an egg-independent production procedure based on a permanent cell line. In the present article, the generation of a complementing Vero cell line suitable for the production of safe poxviral vaccines is described. This cell line was used to produce a replication-deficient vaccinia virus vector H5N1 live vaccine, dVV-HA5, expressing the hemagglutinin of a virulent clade 1 H5N1 strain. This experimental vaccine was compared with a formalin-inactivated whole-virus vaccine based on the same clade and with different replicating poxvirus-vectored vaccines. Mice were immunized to assess protective immunity after high-dose challenge with the highly virulent A/Vietnam/1203/2004(H5N1) strain. A single dose of the defective live vaccine induced complete protection from lethal homologous virus challenge and also full cross-protection against clade 0 and 2 challenge viruses. Neutralizing antibody levels were comparable to those induced by the inactivated vaccine. Unlike the whole-virus vaccine, the dVV-HA5 vaccine induced substantial amounts of gamma interferon-secreting CD8 T cells. Thus, the nonreplicating recombinant vaccinia virus vectors are promising vaccine candidates that induce a broad immune response and can be produced in an egg-independent and adjuvant-independent manner in a proven vector system. PMID:19279103

  1. Evaluation of physicochemical and biological properties of chitosan/poly (vinyl alcohol) polymer blend membranes and their correlation for Vero cell growth.

    PubMed

    Sharma, Parul; Mathur, Garima; Dhakate, Sanjay R; Chand, Subhash; Goswami, Navendu; Sharma, Sanjeev K; Mathur, Ashwani

    2016-02-10

    The blend membranes with varying weight ratios of chitosan/poly (vinyl alcohol) (CS/PVA) (1:0, 1:1, 1:2.5, 1.5:1, 1.5: 2.5) were prepared using solvent casting method and were evaluated for their potential application in single-use membrane bioreactors (MBRs). The physicochemical properties of the prepared membranes were investigated for chemical interactions (FTIR), surface morphology (SEM), water uptake, protein sorption (qe), ammonia sorption and growth kinetics of Vero cells. CS/PVA blend membrane having weight ratio of 1.5:1 had shown enhanced membrane flexibility, reduced water uptake, less protein sorption and no ammonium sorption compared to CS membrane. This blend membrane also showed comparatively enhanced higher specific growth rate (0.82/day) of Vero cells. Improved physicochemical properties and growth kinetics obtrude CS/PVA (1.5:1) as a potential surface for adhesion and proliferation with possible application in single use membrane bioreactors. Additionally, new insight explaining correlation between water holding (%) of CS/PVA (1.5:1) blend membrane and doubling time (td) of Vero cells is proposed. PMID:26686166

  2. Immunogenicity and safety of purified Vero-cell rabies vaccine in severely rabies-exposed patients in China.

    PubMed

    Wang, X J; Lang, J; Tao, X R; Shu, J D; Le Mener, V; Wood, S C; Huang, J T; Zhao, S L

    2000-06-01

    The immunogenicity and safety of a purified Vero-cell rabies vaccine (PVRV, VERORAB; Aventis Pasteur, France) were evaluated in 171 patients treated for severe exposure to rabies (WHO category III contacts) at the Shandong Provincial Antiepidemic Station in Jinan and an EPI center in Ping Yin, China. Post-exposure treatment consisted of a single dose of equine rabies immunoglobulin (ERIG, 40 IU/kg body weight) on Day (D) 0, and intra-muscular administration of PVRV on D 0, 3, 7, 14 and 28. Antirabies antibody levels were evaluated on D 0, 7, 14, 28, 90 and 180 using the rapid fluorescent focus inhibition test. By D 14 all subjects had seroconverted (> or = 0.5 IU/ml), with a geometric mean titer of 50.3 IU/ml. Antibody titers remained above the seroprotection threshold in all patients for 3 months, and in 98.2% of subjects for 6 months. All patients were still alive 6 months after the start of treatment. PVRV and ERIG were shown to be well tolerated and no serious adverse events were observed. Following PVRV administration, 12 patients (7.0%) had at least one local reaction (mostly pruritus, erythematous rash and pain). Fourteen patients (8.2%) developed local reactions at the site of ERIG administration. Twelve patients (7.0%) developed systemic reactions following post-exposure treatment, the most frequent of which were pruritus, rash and vertigo. This study demonstrates that PVRV is immunogenic and safe in Chinese patients treated according to WHO recommendations for severe rabies exposure. PMID:11127328

  3. Neutralizing Antibody Response after Intramuscular Purified Vero Cell Rabies Vaccination (PVRV) in Iranian Patients with Specific Medical Conditions

    PubMed Central

    Rahimi, Pooneh; Vahabpour, RouhAllah; Aghasadeghi, Mohammad Reza; Sadat, Syed Mehdi; Howaizi, Nader; Mostafavi, Ehsan; Eslamifar, Ali; Fallahian, Vida

    2015-01-01

    Objective Post exposure prophylaxis using one of the WHO-approved vaccines is the method of choice for preventing rabies. Abnormal immune function in patients with some specific medical conditions, such as pregnancy, chronic hepatitis B virus infection, different types of cancers like lymphoma, diabetes I and II, corticosteroid consumption by patients with rheumatoid arthritis and lupus erythematosus, could impair the immunologic response to various vaccines. The immune response to rabies vaccination has never been examined in patients with any of these described medical conditions. This study purposed to evaluate the neutralyzing antibody response after vaccination with purified Vero cell rabies vaccine (PVRV) according to the WHO-recommended Post–Exposure Prophylaxis (PEP) "ESSEN" regimen. Methods Thirty healthy volunteers and 50 volunteers with different medical conditions who were exposed to a suspected rabid animal in the 2nd or 3rd category of exposure received 5 doses of PVRV under the ESSEN protocol. Three blood samples were collected on days 0 (before the first dose), 14, and 35. The anti-rabies antibody titer was measured using the Rapid Fluorescent Foci Inhibition Test (RFFIT) and an ELISA Bio-Rad, Platelia, Rabies II kit. Results All subjects reached NAb titers above 0.5 IU/ml by day 14 after vaccination. On day 35 (1 week after receiving the last rabies vaccine), anti-rabies antibodies were in the protective level (>0.5 IU/ml) in both groups. There was no statistically significant difference in anti-rabies antibody response due to the type of exposure (category 2 or 3), and successful seroconversion was confirmed in both groups. Conclusion In conclusion, the ESSEN protocol using the PVRV vaccine is sufficient for rabies prophylaxis in patients with specific medical conditions. PMID:26440665

  4. In vitro anthelmintic activity of the Zizyphus joazeiro bark against gastrointestinal nematodes of goats and its cytotoxicity on Vero cells.

    PubMed

    Gomes, Danilo Cavalcanti; de Lima, Hélimar Gonçalves; Vaz, Ariádne Vieira; Santos, Nathália Silva; Santos, Francianne Oliveira; Dias, Êuder Reis; Botura, Mariana Borges; Branco, Alexsandro; Batatinha, Maria José Moreira

    2016-08-15

    This study examined the in vitro effect of the Zizyphus joazeiro bark against gastrointestinal nematodes of goats and its cytotoxicity on Vero cells. The ovicidal activity of the crude hydroethanolic extract (CE), its partitioned hexane (HE) and aqueous extract (AE) and saponins fraction (SF), including betulinic acid (BA), a biogenetic compound from this plant found in HE, were investigated using the inhibition of egg hatch assay (EHA). Thereafter, the extracts and the SF were evaluated through the larval motility assay (LMA) and larval migration inhibition assay (LMIA). The AE and SF promoted a complete inhibition of the egg hatch, and the effective concentration to inhibit 50% (EC50) values was 1.9 and 1.3mg/mL, respectively. The highest percentages of inhibition in EHA observed after treatments with CE, HE and BA corresponded to 79, 48 and 17%, respectively. The extracts and SF did not show larvicidal activity in LMA and LMIA. The AE and SF demonstrated cytotoxic effects in 3-4,5-dimethylthiazol-2-yl, 2,5diphenyltetrazolium bromide (MTT) and trypan blue tests; however, SF was more toxic (50% inhibitory concentration, IC50=0.20mg/mL). The chemical characterization of the SF was made through Proton Nuclear Magnetic Resonance ((1)H NMR) and Electrospray Ionization Mass Spectrometry (ESI-MS) analyses, which led to the identification of two saponins known as Joazeiroside B and Lotoside A. The results obtained from the research of this saponin content provide important information about the biological activity, especially the anthelmintic effect present in the plant investigated. That also suggests the types of bioactive compounds that may be responsible for this antiparasitic activity exhibited by the plant extracts. PMID:27514875

  5. Reduction of spiked porcine circovirus during the manufacture of a Vero cell-derived vaccine.

    PubMed

    Lackner, Cornelia; Leydold, Sandra M; Modrof, Jens; Farcet, Maria R; Grillberger, Leopold; Schäfer, Birgit; Anderle, Heinz; Kreil, Thomas R

    2014-04-11

    Porcine circovirus-1 (PCV1) was recently identified as a contaminant in live Rotavirus vaccines, which was likely caused by contaminated porcine trypsin. The event triggered the development of new regulatory guidance on the use of porcine trypsin which shall ensure that cell lines and porcine trypsin in use are free from PCV1. In addition, manufacturing processes of biologicals other than live vaccines include virus clearance steps that may prevent and mitigate any potential virus contamination of product. In this work, artificial spiking of down-scaled models for the manufacturing process of an inactivated pandemic influenza virus vaccine were used to investigate inactivation of PCV1 and the physico-chemically related porcine parvovirus (PPV) by formalin and ultraviolet-C (UV-C) treatment as well as removal by the purification step sucrose gradient ultracentrifugation. A PCV1 infectivity assay, using a real-time PCR infectivity readout was established. The formalin treatment (0.05% for 48h) showed substantial inactivation for both PCV1 and PPV with reduction factors of 3.0log10 and 6.8log10, respectively, whereas UV-C treatment resulted in complete PPV (≥5.9log10) inactivation already at a dose of 13mJ/cm but merely 1.7log10 at 24mJ/cm(2) for PCV1. The UV-C inactivation results with PPV were confirmed using minute virus of mice (MVM), indicating that parvoviruses are far more sensitive to UV-C than PCV1. The sucrose density gradient ultracentrifugation also contributed to PCV1 clearance with a reduction factor of 2log10. The low pH treatment during the production of procine trypsin was investigated and showed effective inactivation for both PCV1 (4.5log10) and PPV (6.4log10). In conclusion, PCV1 in general appears to be more resistant to virus inactivation than PPV. Still, the inactivated pandemic influenza vaccine manufacturing process provides for robust virus reduction, in addition to the already implemented testing for PCV1 to avoid any contaminations. PMID

  6. Transcriptional profiling of Vero E6 cells over-expressing SARS-CoV S2 subunit: Insights on viral regulation of apoptosis and proliferation

    SciTech Connect

    Yeung, Y.-S. Yip, C.-W. Hon, C.-C. Chow, Ken Y.C. Ma, Iris C.M. Zeng Fanya Leung, Frederick C.C.

    2008-02-05

    We have previously demonstrated that over-expression of spike protein (S) of severe acute respiratory syndrome coronavirus (SARS-CoV) or its C-terminal subunit (S2) is sufficient to induce apoptosis in vitro. To further investigate the possible roles of S2 in SARS-CoV-induced apoptosis and pathogenesis of SARS, we characterized the host expression profiles induced upon S2 over-expression in Vero E6 cells by oligonucleotide microarray analysis. Possible activation of mitochondrial apoptotic pathway in S2 expressing cells was suggested, as evidenced by the up-regulation of cytochrome c and down-regulation of the Bcl-2 family anti-apoptotic members. Inhibition of Bcl-2-related anti-apoptotic pathway was further supported by the diminution of S2-induced apoptosis in Vero E6 cells over-expressing Bcl-xL. In addition, modulation of CCN E2 and CDKN 1A implied the possible control of cell cycle arrest at G1/S phase. This study is expected to extend our understanding on the pathogenesis of SARS at a molecular level.

  7. Immunogenicity and Protective Efficacy of a Vero Cell Culture-Derived Whole-Virus H7N9 Vaccine in Mice and Guinea Pigs

    PubMed Central

    Wodal, Walter; Schwendinger, Michael G.; Savidis-Dacho, Helga; Crowe, Brian A.; Hohenadl, Christine; Fritz, Richard; Brühl, Peter; Portsmouth, Daniel; Karner-Pichl, Anita; Balta, Dalida; Grillberger, Leopold; Kistner, Otfried; Barrett, P. Noel; Howard, M. Keith

    2015-01-01

    Background A novel avian H7N9 virus with a high case fatality rate in humans emerged in China in 2013. We evaluated the immunogenicity and protective efficacy of a candidate Vero cell culture-derived whole-virus H7N9 vaccine in small animal models. Methods Antibody responses induced in immunized DBA/2J mice and guinea pigs were evaluated by hemagglutination inhibition (HI), microneutralization (MN), and neuraminidase inhibition (NAi) assays. T-helper cell responses and IgG subclass responses in mice were analyzed by ELISPOT and ELISA, respectively. Vaccine efficacy against lethal challenge with wild-type H7N9 virus was evaluated in immunized mice. H7N9-specific antibody responses induced in mice and guinea pigs were compared to those induced by a licensed whole-virus pandemic H1N1 (H1N1pdm09) vaccine. Results The whole-virus H7N9 vaccine induced dose-dependent H7N9-specific HI, MN and NAi antibodies in mice and guinea pigs. Evaluation of T-helper cell responses and IgG subclasses indicated the induction of a balanced Th1/Th2 response. Immunized mice were protected against lethal H7N9 challenge in a dose-dependent manner. H7N9 and H1N1pdm09 vaccines were similarly immunogenic. Conclusions The induction of H7N9-specific antibody and T cell responses and protection against lethal challenge suggest that the Vero cell culture-derived whole-virus vaccine would provide an effective intervention against the H7N9 virus. PMID:25719901

  8. Comparison of human immune responses to purified Vero cell and human diploid cell rabies vaccines by using two different antibody titration methods.

    PubMed Central

    Kitala, P M; Lindqvist, K J; Koimett, E; Johnson, B K; Chunge, C N; Perrin, P; Olsvik, O

    1990-01-01

    Antibody responses to a conventional rabies preexposure regimen of a new purified Vero cell rabies vaccine (PVRV) and a human diploid cell vaccine (HDCV) were compared in 80 healthy Kenyan veterinary students. Forty-three of the students received the PVRV and 37 received the HDCV on days 0, 7, and 28. Antibody responses were monitored by using the rapid fluorescent-focus inhibition test (RFFIT) and an inhibition enzyme immunoassay (INH EIA) on days 0, 7, 28, and 49. Both vaccines elicited a rapid antibody response. A good correlation between the RFFIT titers and the INH EIA titers was obtained (r = 0.90). Our results also showed that the INH EIA was more reproducible and might therefore be a suitable substitute for the more expensive and less reproducible RFFIT. The geometric mean titers determined by both tests in the two groups of students were statistically similar during the test period. The RFFIT and the INH EIA gave comparable geometric mean titers, which differed significantly only on day 28 in the PVRV group. The effect of the new PVRV is comparable to that of the more expensive HDCV, as determined by the present test systems. The PVRV could therefore be the vaccine of choice, especially in tropical rabies-endemic areas, where the high cost of the HDCV has confined its use to a privileged few. PMID:2203814

  9. Preparation and characterization of an anti-inflammatory agent based on a zinc-layered hydroxide-salicylate nanohybrid and its effect on viability of Vero-3 cells.

    PubMed

    Ramli, Munirah; Hussein, Mohd Zobir; Yusoff, Khatijah

    2013-01-01

    A new organic-inorganic nanohybrid based on zinc-layered hydroxide intercalated with an anti-inflammatory agent was synthesized through direct reaction of salicylic acid at various concentrations with commercially available zinc oxide. The basal spacing of the pure phase nanohybrid was 15.73 Å, with the salicylate anions arranged in a monolayer form and an angle of 57 degrees between the zinc-layered hydroxide interlayers. Fourier transform infrared study further confirmed intercalation of salicylate into the interlayers of zinc-layered hydroxide. The loading of salicylate in the nanohybrid was estimated to be around 29.66%, and the nanohybrid exhibited the properties of a mesoporous-type material, with greatly enhanced thermal stability of the salicylate compared with its free counterpart. In vitro cytotoxicity assay revealed that free salicylic acid, pure zinc oxide, and the nanohybrid have a mild effect on viability of African green monkey kidney (Vero-3) cells. PMID:23345976

  10. Preparation and characterization of an anti-inflammatory agent based on a zinc-layered hydroxide-salicylate nanohybrid and its effect on viability of Vero-3 cells

    PubMed Central

    Ramli, Munirah; Hussein, Mohd Zobir; Yusoff, Khatijah

    2013-01-01

    A new organic-inorganic nanohybrid based on zinc-layered hydroxide intercalated with an anti-inflammatory agent was synthesized through direct reaction of salicylic acid at various concentrations with commercially available zinc oxide. The basal spacing of the pure phase nanohybrid was 15.73 Å, with the salicylate anions arranged in a monolayer form and an angle of 57 degrees between the zinc-layered hydroxide interlayers. Fourier transform infrared study further confirmed intercalation of salicylate into the interlayers of zinc-layered hydroxide. The loading of salicylate in the nanohybrid was estimated to be around 29.66%, and the nanohybrid exhibited the properties of a mesoporous-type material, with greatly enhanced thermal stability of the salicylate compared with its free counterpart. In vitro cytotoxicity assay revealed that free salicylic acid, pure zinc oxide, and the nanohybrid have a mild effect on viability of African green monkey kidney (Vero-3) cells. PMID:23345976

  11. Antibody response of patients after postexposure rabies vaccination with small intradermal doses of purified chick embryo cell vaccine or purified Vero cell rabies vaccine.

    PubMed Central

    Briggs, D. J.; Banzhoff, A.; Nicolay, U.; Sirikwin, S.; Dumavibhat, B.; Tongswas, S.; Wasi, C.

    2000-01-01

    Although the introduction of tissue culture vaccines for rabies has dramatically improved the immunogenicity and safety of rabies vaccines, they are often prohibitively expensive for developing countries. To examine whether smaller doses of these vaccines could be used, we tested the safety and immunogenicity of purified chick embryo cell vaccine (PCECV) on 211 patients in Thailand with World Health Organization (WHO) category II and III exposures to rabies. The patients presented at two Thai hospitals and were randomized into three groups. Patients in Group 1 received 0.1 ml PCECV intradermally at two sites on days 0, 3, 7, and at one site on days 30 and 90. Group 2 was treated similarly, except that purified Vero cell rabies vaccine (PVRV) was used instead of PCECV. Group 3 received 1.0 ml PCECV intramuscularly on days 0, 3, 7, 14, 30 and 90. After 0, 3, 7, 14, 30 and 90 days serum was collected from the subjects and the geometric mean titres (GMTs) of rabies virus neutralizing antibody determined. After 14 days the GMT of 59 patients vaccinated intradermally with PCECV was equivalent to that of patients who received PVRV. Adverse reactions were more frequent in patients who received vaccines intradermally, indicating the reactions were associated with the route of injection, rather than the vaccine per se. We conclude that PCECV is a safe and highly immunogenic vaccine for postexposure rabies vaccination when administered intradermally in 0.1-ml doses using the two-site method ("2,2,2,0,1,1") recommended by WHO. PMID:10859864

  12. ACAM2000 clonal Vero cell culture vaccinia virus (New York City Board of Health strain)--a second-generation smallpox vaccine for biological defense.

    PubMed

    Monath, Thomas P; Caldwell, Joseph R; Mundt, Wolfgang; Fusco, Joan; Johnson, Casey S; Buller, Mark; Liu, Jian; Gardner, Bridget; Downing, Greg; Blum, Paul S; Kemp, Tracy; Nichols, Richard; Weltzin, Richard

    2004-10-01

    The threat of smallpox as a biological weapon has spurred efforts to create stockpiles of vaccine for emergency preparedness. In lieu of preparing vaccine in animal skin (the original method), we cloned vaccinia virus (New York City Board of Health strain, Dryvax by plaque purification and amplified the clone in cell culture. The overarching goal was to produce a modern vaccine that was equivalent to the currently licensed Dryvax in its preclinical and clinical properties, and could thus reliably protect humans against smallpox. A variety of clones were evaluated, and many were unacceptably virulent in animal models. One clonal virus (ACAM1000) was selected and produced at clinical grade in MRC-5 human diploid cells. ACAM1000 was comparable to Dryvax in immunogenicity and protective activity but was less neurovirulent for mice and nonhuman primates. To meet requirements for large quantities of vaccine after the events of September 11th 2001, the ACAM1000 master virus seed was used to prepare vaccine (designated ACAM2000) at large scale in Vero cells under serum-free conditions. The genomes of ACAM1000 and ACAM2000 had identical nucleotide sequences, and the vaccines had comparable biological phenotypes. ACAM1000 and ACAM2000 were evaluated in three Phase 1 clinical trials. The vaccines produced major cutaneous reactions and evoked neutralizing antibody and cell-mediated immune responses in the vast majority of subjects and had a reactogenicity profile similar to that of Dryvax. PMID:15491873

  13. Colon tumor cells grown in NASA Bioreactor

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These photos compare the results of colon carcinoma cells grown in a NASA Bioreactor flown on the STS-70 Space Shuttle in 1995 flight and ground control experiments. The cells grown in microgravity (left) have aggregated to form masses that are larger and more similar to tissue found in the body than the cells cultured on the ground (right). The principal investigator is Milburn Jessup of the University of Texas M. D. Anderson Cancer Center. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Credit: NASA and University of Texas M. D. Anderson Cancer Center.

  14. Evaluation and Comparison of the In Vitro Cytotoxic Activity of Withania somnifera Methanolic and Ethanolic Extracts against MDA-MB-231 and Vero Cell Lines.

    PubMed

    Srivastava, A N; Ahmad, Rumana; Khan, Mohsin Ali

    2016-01-01

    Withania somnifera Dunal (WS), commonly known as Ashwagandha in India, belongs to the family Solanaceae. It is extensively used in most of the Indian herbal pharmaceuticals and nutraceuticals. In the current study, the in vitro cytotoxic activity of methanolic, ethanolic, and aqueous extracts of WS stems was evaluated using cytometry and the MTT assay against the MDA-MB-231 human breast cancer cell line. Methanolic and ethanolic extracts of WS showed potent anticancer activity on the MDA-MB-231 human breast cancer cell line, whereas the aqueous extract did not exhibit any significant activity at 100 µg/ml. The percentage viability of the cell lines was determined by using the Trypan blue dye exclusion method. Cell viability was reduced to 21% and 0% at 50 and 100 µg/ml of the methanolic extract, respectively, as compared to 19% and 0% at 50 and 100 µg/ml for the ethanolic extract and 37% at 100 µg/ml in sterile Milli-Q water after 48 hours of treatment. Methanolic and ethanolic extracts of WS were shown to possess IC50 values of 30 and 37 µg/ml, respectively, by the MTT assay and cytometer-based analysis, with the methanolic extract being more active than the other two. On the other hand, methanolic and ethanolic extracts of WS did not exhibit any significant in vitro activity against the normal epithelial cell line Vero at 50 µg/ml. HPLC was carried out for the analysis of its phytochemical profile and demonstrated the presence of the active component Withaferin A in both extracts. The methanolic and ethanolic extracts of Withania should be studied further for the isolation and characterization of the active components to lead optimization studies. PMID:27110497

  15. Evaluation and Comparison of the In Vitro Cytotoxic Activity of Withania somnifera Methanolic and Ethanolic Extracts against MDA-MB-231 and Vero Cell Lines

    PubMed Central

    Srivastava, A. N.; Ahmad, Rumana; Khan, Mohsin Ali

    2016-01-01

    Withania somnifera Dunal (WS), commonly known as Ashwagandha in India, belongs to the family Solanaceae. It is extensively used in most of the Indian herbal pharmaceuticals and nutraceuticals. In the current study, the in vitro cytotoxic activity of methanolic, ethanolic, and aqueous extracts of WS stems was evaluated using cytometry and the MTT assay against the MDA-MB-231 human breast cancer cell line. Methanolic and ethanolic extracts of WS showed potent anticancer activity on the MDA-MB-231 human breast cancer cell line, whereas the aqueous extract did not exhibit any significant activity at 100 µg/ml. The percentage viability of the cell lines was determined by using the Trypan blue dye exclusion method. Cell viability was reduced to 21% and 0% at 50 and 100 µg/ml of the methanolic extract, respectively, as compared to 19% and 0% at 50 and 100 µg/ml for the ethanolic extract and 37% at 100 µg/ml in sterile Milli-Q water after 48 hours of treatment. Methanolic and ethanolic extracts of WS were shown to possess IC50 values of 30 and 37 µg/ml, respectively, by the MTT assay and cytometer-based analysis, with the methanolic extract being more active than the other two. On the other hand, methanolic and ethanolic extracts of WS did not exhibit any significant in vitro activity against the normal epithelial cell line Vero at 50 µg/ml. HPLC was carried out for the analysis of its phytochemical profile and demonstrated the presence of the active component Withaferin A in both extracts. The methanolic and ethanolic extracts of Withania should be studied further for the isolation and characterization of the active components to lead optimization studies. PMID:27110497

  16. Sensitivity of light-grown and dark-grown Euglena cells to gamma-irradiation.

    PubMed

    Nair, K A; Netrawali, M S

    1979-09-01

    Light-grown cells which contain fully developed chloroplasts were found to be more resistant to gamma-irradiation than dark-grown cells which are devoid of chloroplasts. The radio-resistance of dark-grown cells progressively increased during light-induced development of chloroplasts and, conversely, radio-resistance of light-grown cells decreased progressively with chloroplast de-development during growth in the dark. The presence of chloroplasts seemed to play a major role in the capacity of cells to recover from radiation damage, the efficiency of cellular recovery being correlatable with the degree of chloroplast development. PMID:315395

  17. Human respiratory syncytial virus Memphis 37 grown in HEp-2 cells causes more severe disease in lambs than virus grown in vero cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in infants and young children. A small percentage of these individuals develop severe and even fatal disease. To better understand the pathogenesis of severe disease and develop therapies unique to the less-developed infan...

  18. Comparative study on the cytotoxicity of different Myrtaceae essential oils on cultured vero and RC-37 cells.

    PubMed

    Schnitzler, P; Wiesenhofer, K; Reichling, J

    2008-11-01

    Medicinally and commercially important essential oils from the family Myrtaceae, i.e. cajuput, clove, kanuka and manuka were phytochemically analysed by GC-MS. Cytotoxicity of these essential oils was evaluated in a standard neutral red assay. Maximum noncytotoxic concentrations for cajuput oil and clove oil were determined at 0.006%, kanuka oil and manuka oil were more cytotoxic with a maximum noncytotoxic concentration of 0.001%. The compounds alpha-pinene, eugenol and leptospermone demonstrated maximum noncytotoxic concentrations at dilutions of 0.001%, 0.003% and 0.001%, respectively. However, the terpene 1,8-cineole was about 100 times less toxic to cultured cells with a maximum noncytotoxic concentration of 0.1% and a TC50 value of 0.44%. Manuka essential oil exhibited high levels of virucidal activity against HSV-1 as well against drug-resistant HSV-1 isolates in viral suspension tests. Determination of cytotoxicity of natural products is an important prerequisite for application in cosmetic and health care products and in antiviral tests. PMID:19069246

  19. Subtilase cytotoxin, produced by Shiga-toxigenic Escherichia coli, transiently inhibits protein synthesis of Vero cells via degradation of BiP and induces cell cycle arrest at G1 by downregulation of cyclin D1.

    PubMed

    Morinaga, Naoko; Yahiro, Kinnosuke; Matsuura, Gen; Moss, Joel; Noda, Masatoshi

    2008-04-01

    Subtilase cytotoxin (SubAB) is a AB(5) type toxin produced by Shiga-toxigenic Escherichia coli, which exhibits cytotoxicity to Vero cells. SubAB B subunit binds to toxin receptors on the cell surface, whereas the A subunit is a subtilase-like serine protease that specifically cleaves chaperone BiP/Grp78. As noted previously, SubAB caused inhibition of protein synthesis. We now show that the inhibition of protein synthesis was transient and occurred as a result of ER stress induced by cleavage of BiP; it was closely associated with phosphorylation of double-stranded RNA-activated protein kinase-like ER kinase (PERK) and eukaryotic initiation factor-2alpha (eIF2alpha). The phosphorylation of PERK and eIF2alpha was maximal at 30-60 min and then returned to the control level. Protein synthesis after treatment of cells with SubAB was suppressed for 2 h and recovered, followed by induction of stress-inducible C/EBP-homologous protein (CHOP). BiP degradation continued, however, even after protein synthesis recovered. SubAB-treated cells showed cell cycle arrest in G1 phase, which may result from cyclin D1 downregulation caused by both SubAB-induced translational inhibition and continuous prolonged proteasomal degradation. PMID:18005237

  20. Preparation of genetically engineered A/H5N1 and A/H7N1 pandemic vaccine viruses by reverse genetics in a mixture of Vero and chicken embryo cells

    PubMed Central

    Legastelois, Isabelle; Garcia‐Sastre, Adolfo; Palese, Peter; Tumpey, Terrence M.; Maines, Taronna R.; Katz, Jacqueline M.; Vogel, Frederick R.; Moste, Catherine

    2007-01-01

    Background  In case of influenza pandemic, a robust, easy and clean technique to prepare reassortants would be necessary. Objectives  Using reverse genetics, we prepared two vaccine reassortants (A/H5N1 × PR8 and A/H7N1 × PR8) exhibiting the envelope glycoproteins from non‐pathogenic avian viruses, A/Turkey/Wisconsin/68 (A/H5N9) and A/Rhea/New Caledonia/39482/93 (A/H7N1) and the internal proteins of the attenuated human virus A/Puerto Rico/8/34 (H1N1). Methods  The transfection was accomplished using a mixture of Vero and chicken embryo cells both of which are currently being used for vaccine manufacturing. Results  This process was reproducible, resulting in consistent recovery of influenza viruses in 6 days. Because it is mainly the A/H5N1 strain that has recently crossed the human barrier, it is the A/PR8 × A/H5N1 reassortant (RG5) that was further amplified, either in embryonated hen eggs or Vero cells, to produce vaccine pre‐master seed stocks that met quality control specifications. Safety testing in chickens and ferrets was performed to assess the non‐virulence of the reassortant, and finally analysis using chicken and ferret sera immunized with the RG5 virus showed that the vaccine candidate elicited an antibody response cross‐reactive with the Hong Kong 1997 and 2003 H5N1 strains but not the Vietnam/2004 viruses. Conclusions  The seeds obtained could be used as part of a pandemic vaccine strain ‘library’ available in case of propagation in humans of a new highly pathogenic avian strain. PMID:19453414

  1. OM-VPE grown materials for high efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Saxena, R.; Cooper, B., III; Ludowise, M.; Borden, P.; Gregory, P.

    1980-01-01

    Organometallic sources are available for all the III-V elements and a variety of dopants; thus it is possible to use the technique to grow a wide variety of semiconductor compounds. AlGaAsSb and AlGaInAs alloys for multijunction monolithic solar cells were grown by OM-VPE. While the effort concentrated on terrestrial applications, the success of OM-VPE grown GaAs/AlGaAs concentrator solar cells (23% at 400 suns) demonstrates that OM-VPE is suitable for growing high efficiency solar cells in large quantities for space applications. In addition, OM-VPE offers the potential for substantial cost reduction of photovoltaic devices with scale up and automation and due to high process yield from reproducible, uniform epitaxial growths with excellent surface morphology.

  2. Comparison of vero cell plaque assay, TaqMan reverse transcriptase polymerase chain reaction RNA assay, and VecTest antigen assay for detection of West Nile virus in field-collected mosquitoes.

    PubMed

    Nasci, Roger S; Gottfried, Kristy L; Burkhalter, Kristen L; Kulasekera, Varuni L; Lambert, Amy J; Lanciotti, Robert S; Hunt, Ann R; Ryan, Jeffrey R

    2002-12-01

    Mosquitoes collected during the epidemic of West Nile virus (WN) in Staten Island, NY, during 2000 were identified to species, grouped into pools of up to 50 individuals, and tested for the presence of WN by using TaqMan reverse transcriptase polymerase chain reaction (RT-PCR) to detect West Nile viral RNA, Vero cell plaque assay to detect infectious virus, and VecTest WNV/SLE Antigen Panel Assay. A total of 10,866 specimens was tested in 801 pools. Analysis of results indicated that TaqMan RT-PCR detected 34 WN-positive pools, more than either of the other techniques. The plaque assay detected 74% of the pools positive by TaqMan, and VecTest detected 60% of the pools positive by TaqMan. The VecTest assay detected evidence of West Nile viral antigen in 67% of the pools that contained live virus detected by plaque assay. A WN enzyme immunoassay performed similarly to the VecTest WN assay. Differences in performance were related to relative sensitivity of the tests. Infection rates of WN in Culex pipiens and Cx. salinarius calculated by the 3 techniques varied, but each estimate indicated a high infection rate in the population. Positive and negative attributes of each procedure, which may influence how and where they are used in surveillance programs, are discussed. PMID:12542186

  3. Lactobacillus plantarum LB95 impairs the virulence potential of Gram-positive and Gram-negative food-borne pathogens in HT-29 and Vero cell cultures.

    PubMed

    Dutra, Virna; Silva, Ana Carla; Cabrita, Paula; Peres, Cidália; Malcata, Xavier; Brito, Luisa

    2016-01-01

    Listeria monocytogenes, Salmonella enterica and verocytotoxigenic Escherichia coli (VTEC) are amongst the most important agents responsible for food outbreaks occurring worldwide. In this work, two Lactobacillus spp. strains (LABs), Lactobacillus plantarum (LB95) and Lactobacillus paraplantarum (LB13), previously isolated from spontaneously fermenting olive brines, and two reference probiotic strains, Lactobacillus casei Shirota and Lactobacillus rhamnosus GG, were investigated for their ability to attenuate the virulence of the aforementioned pathogens using animal cell culture assays. In competitive exclusion assays, the relative percentages of adhesion and invasion of S. enterica subsp. enterica serovar Enteritidis were significantly reduced when the human HT-29 cell line was previously exposed to LB95. The relative percentage of invasion by Listeria monocytogenes was significantly reduced when HT-29 cells were previously exposed to LB95. In the cytotoxicity assays, the cell-free supernatant of the co-culture (CFSC)of VTEC with LB95 accounted for the lowest value obtained amongst the co-cultures of VTEC with LABs, and was significantly lower than the value obtained with the co-culture of VTEC with the two probiotic reference strains. The cytotoxicity of CFSC of VTEC with both LB95 and LB13 exhibited values not significantly different from the cell-free supernatant of the nonpathogenic E. coli B strain. Our results suggested that LB95 may be able to attenuate the virulence of Gram-positive and Gram-negative food-borne pathogens; together with other reported features of these strains, our data reveal their possible use in probiotic foods due to their interesting potential in preventing enteric infections in humans. PMID:26506821

  4. Role of Proteus mirabilis MR/P fimbriae and flagella in adhesion, cytotoxicity and genotoxicity induction in T24 and Vero cells.

    PubMed

    Scavone, Paola; Villar, Silvia; Umpiérrez, Ana; Zunino, Pablo

    2015-06-01

    Proteus mirabilis is frequently associated with complicated urinary tract infections (UTI). It is proposed that several virulence factors are associated with P. mirabilis uropathogenicity. The aim of this work was to elucidate genotoxic and cytotoxic effects mediated by MR/P fimbriae and flagella in eukaryotic cells in vitro. Two cell lines (kidney- and bladder-derived) were infected with a clinical wild-type P. mirabilis strain and an MR/P and a flagellar mutant. We evaluated adhesion, genotoxicity and cytotoxicity by microscopy, comet assay and triple staining technique, respectively. Mutant strains displayed lower adhesion rates than the P. mirabilis wild-type strain and were significantly less effective to induce genotoxic and cytotoxic effects compared to the wild type. We report for the first time that P. mirabilis MR/P fimbriae and flagella mediate genotoxic and cytotoxic effects on eukaryotic cells, at least in in vitro conditions. These results could contribute to design new strategies for the control of UTI. PMID:25724892

  5. Evaluation of the safety, immunogenicity, and pharmacokinetic profile of a new, highly purified, heat-treated equine rabies immunoglobulin, administered either alone or in association with a purified, Vero-cell rabies vaccine.

    PubMed

    Lang, J; Attanath, P; Quiambao, B; Singhasivanon, V; Chanthavanich, P; Montalban, C; Lutsch, C; Pepin-Covatta, S; Le Mener, V; Miranda, M; Sabchareon, A

    1998-07-30

    A clinical evaluation of a new, purified, heat-treated equine rabies immunoglobulin (PHT-Erig), F(ab')2 preparation, was carried out in Thailand and in the Philippines-two countries where rabies is endemic. An initial prospective, randomised, controlled trial (Study 1), compared the safety and pharmacokinetics (serum concentrations of rabies antibodies) after administration either of PHT-Erig or of a commercially-available, equine rabies immune globulin (Erig PMC). A second trial (Study 2) simulated post-exposure rabies prophylaxis by using a reference cell culture vaccine, the purified Vero-cell rabies vaccine (PVRV), administered in association with either Erig PMC or PHT-Erig. In Study 1, 27 healthy, Thai adults received a 40 IU kg(-1) dose of either Erig PMC (n = 12) or PHT-Erig (n = 15) via the intramuscular (i.m.) route; half of the dose was injected into the deltoid area and the other half into the buttocks. Serum for rabies antibody determination and F(ab')2 concentration was collected at hours (H) 0, 6 and 12, and on day (D) 2, 3, 4, 6, 8, 10, 12 and 15. Both products were safe, with no serious adverse events, and in particular, no anaphylactic reactions or serum sickness was reported. A statistical comparison of the pharmacokinetic parameters did not demonstrate bioequivalence of the two products. Nonetheless, the relative bioavailability of 93% and the similar absorption rates suggest the pharmacokinetic profiles of Erig and PHT-Erig are similar. The antibody level in either group were low throughout the 15-day study period. The geometric mean titer (GMT) values ranged from group 0.027-0.117 IU ml(-1) in the Erig group and from 0.029 to 0.072 IU ml(-1) in the PHT-Erig. There was no significant difference between the evolution of GMT values for the two groups. In Study 2, 71 healthy volunteers received 40 IU kg(-1) via the intramuscular route of either Erig PMC (n = 36) or PHT-Erig (n = 35) on D0, in association with five doses of PVRV on D0, D3, D7, D14

  6. Multiband spectral emitters matched to MBE grown photovoltaic cells

    SciTech Connect

    Wong, E.M.; Hickey, J.P.; Holmquist, G.A.; Uppal, P.N.; Waldman, C.H.

    1996-02-01

    Clearly TPV devices are of considerable interest for power generation. For practical devices it is desirable to have high efficiencies combined with low temperature operation. Photovoltaic cells which can convert the energy at the longer wavelengths of interest are needed to complete such a system. The spectral emission peak of Yb{sub 2}O{sub 3} is well matched to the band gap of Si; however, the longer wavelength, spectral emissions of other rare earth oxides can also be exploited through the use of III{endash}V semiconductor compounds such as GaSb or alloys of GaInAsSb. By doping GaSb with InAs, the band gap of the resulting material can be effectively varied depending upon the concentration of InAs in the quaternary alloy. The ability to tailor the emitter materials and, in conjunction, the photovoltaic materials leads to greater efficiencies through spectral matching. Two binary rare earth oxide combinations, Er{sub 2}O{sub 3}/Ho{sub 2}O{sub 3} and Er{sub 2}O{sub 3}/Yb{sub 2}O{sub 3}, were studied. The mixtures were found to give multiple peak spectral emission in the wavelengths of interest. The intensity of the peaks were compositionally dependent though it did not vary in a linear fashion. Photon efficiencies of the molecular beam epitaxially (MBE) grown GaSb cell and GaInAsSb quaternary cell were measured when used in conjunction with the Er{sub 2}O{sub 3}/Ho{sub 2}O{sub 3} emitters in which the concentration of Er{sub 2}O{sub 3} and Ho{sub 2}O{sub 3} were varied. The results demonstrated promise for further work. {copyright} {ital 1996 American Institute of Physics.}

  7. Thin film solar cells grown by organic vapor phase deposition

    NASA Astrophysics Data System (ADS)

    Yang, Fan

    Organic solar cells have the potential to provide low-cost photovoltaic devices as a clean and renewable energy resource. In this thesis, we focus on understanding the energy conversion process in organic solar cells, and improving the power conversion efficiencies via controlled growth of organic nanostructures. First, we explain the unique optical and electrical properties of organic materials used for photovoltaics, and the excitonic energy conversion process in donor-acceptor heterojunction solar cells that place several limiting factors of their power conversion efficiency. Then, strategies for improving exciton diffusion and carrier collection are analyzed using dynamical Monte Carlo models for several nanostructure morphologies. Organic vapor phase deposition is used for controlling materials crystallization and film morphology. We improve the exciton diffusion efficiency while maintaining good carrier conduction in a bulk heterojunction solar cell. Further efficiency improvement is obtained in a novel nanocrystalline network structure with a thick absorbing layer, leading to the demonstration of an organic solar cell with 4.6% efficiency. In addition, solar cells using simultaneously active heterojunctions with broad spectral response are presented. We also analyze the efficiency limits of single and multiple junction organic solar cells, and discuss the challenges facing their practical implementations.

  8. Prodigiosin Induces Autolysins in Actively Grown Bacillus subtilis Cells.

    PubMed

    Danevčič, Tjaša; Borić Vezjak, Maja; Tabor, Maja; Zorec, Maša; Stopar, David

    2016-01-01

    Prodigiosin produced by marine bacterium Vibrio ruber DSM 14379 exhibits a potent antimicrobial activity against a broad range of Gram positive and Gram negative bacteria. The mechanism of prodigiosin antimicrobial action, however, is not known. In this work, the effect of prodigiosin on Bacillus subtilis growth, cell membrane leakage, and induction of autolysins was studied. Treating B. subtilis with prodigiosin resulted in rapid decline of optical density and increased cell membrane leakage measured by β-galactosidase activity. Cell lysis was initiated immediately after treatment with prodigiosin in the middle exponential phase and was completed within 2 h. Lytic activity of prodigiosin in mutant strains with impaired autolysin genes lytABCD decreased for 80% compared to the wild type strain, while in lytABCDEF mutant strain prodigiosin had no bacteriolytic but only bacteriostatic effect. Fast prodigiosin lytic activity on individual B. subtilis cells was confirmed by a modified comet assay. The results indicate that prodigiosin autolysin induction in B. subtilis is growth phase dependent. PMID:26858704

  9. Prodigiosin Induces Autolysins in Actively Grown Bacillus subtilis Cells

    PubMed Central

    Danevčič, Tjaša; Borić Vezjak, Maja; Tabor, Maja; Zorec, Maša; Stopar, David

    2016-01-01

    Prodigiosin produced by marine bacterium Vibrio ruber DSM 14379 exhibits a potent antimicrobial activity against a broad range of Gram positive and Gram negative bacteria. The mechanism of prodigiosin antimicrobial action, however, is not known. In this work, the effect of prodigiosin on Bacillus subtilis growth, cell membrane leakage, and induction of autolysins was studied. Treating B. subtilis with prodigiosin resulted in rapid decline of optical density and increased cell membrane leakage measured by β-galactosidase activity. Cell lysis was initiated immediately after treatment with prodigiosin in the middle exponential phase and was completed within 2 h. Lytic activity of prodigiosin in mutant strains with impaired autolysin genes lytABCD decreased for 80% compared to the wild type strain, while in lytABCDEF mutant strain prodigiosin had no bacteriolytic but only bacteriostatic effect. Fast prodigiosin lytic activity on individual B. subtilis cells was confirmed by a modified comet assay. The results indicate that prodigiosin autolysin induction in B. subtilis is growth phase dependent. PMID:26858704

  10. Efficient flotation of yeast cells grown in batch culture.

    PubMed

    Palmieri, M C; Greenhalf, W; Laluce, C

    1996-05-01

    A fast flotation assay was used to select new floating yeast strains. The flotation ability did not seem to be directly correlated to total extracellular protein concentration of the culture. However, the hydrophobicity of the cell was definitely correlated to the flotation capacity. The Saccharomyces strains (FLT strains) were highly hydrophobic and showed an excellent flotation performance in batch cultures without additives (flotation agents) and with no need for a special flotation chamber or flotation column. A stable and well-organized structure was evident in the dried foam as shown by scanning electron microscopy which revealed its unique structure showing mummified cells (dehydrated) attached to each other. The attachment among the cells and the high protein concentration of the foams indicated that proteins might be involved in the foam formation. The floating strains (strains FLT) which were not flocculent and showed no tendency to aggregate, were capable of growing and producing ethanol in a synthetic medium containing high glucose concentration as a carbon source. The phenomenon responsible for flotation seems to be quite different from the flocculation phenomenon. PMID:18626952

  11. Plastid distribution in columella cells of a starchless Arabidopsis mutant grown in microgravity

    NASA Technical Reports Server (NTRS)

    Hilaire, E.; Paulsen, A. Q.; Brown, C. S.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1997-01-01

    Wild-type and starchless Arabidopsis thaliana mutant seedlings (TC7) were grown and fixed in the microgravity environment of a U.S. Space Shuttle spaceflight. Computer image analysis of longitudinal sections from columella cells suggest a different plastid positioning mechanism for mutant and wild-type in the absence of gravity.

  12. Cell alignment is induced by cyclic changes in cell length: studies of cells grown in cyclically stretched substrates.

    PubMed

    Neidlinger-Wilke, C; Grood, E S; Wang JH-C; Brand, R A; Claes, L

    2001-03-01

    Many types of cells, when grown on the surface of a cyclically stretched substrate, align away from the stretch direction. Although cell alignment has been described as an avoidance response to stretch, the specific deformation signal that causes a cell population to become aligned has not been identified. Planar surface deformation is characterized by three strains: two normal strains describe the length changes of two initially perpendicular lines and one shear strain describes the change in the angle between the two lines. The present study was designed to determine which, if any, of the three strains was the signal for cell alignment. Human fibroblasts and osteoblasts were grown in deformable, rectangular, silicone culture dishes coated with ProNectin, a biosynthetic polymer containing the RGD ligand of fibronectin. 24 h after plating the cells, the dishes were cyclically stretched at 1 Hz to peak dish stretches of 0% (control), 4%, 8%, and 12%. After 24 h of stretching, the cells were fixed, stained, and their orientations measured. The cell orientation distribution was determined by calculating the percent of cells whose orientation was within each of eighteen 5 degrees angular intervals. We found that the alignment response was primarily driven by the substrate strain which tended to lengthen the cell (axial strain). We also found that for each cell type there was an axial strain limit above which few cells were found. The axial strain limit for fibroblasts, 4.2 +/- 0.4%, (mean +/- 95% confidence), was lower than for osteoblasts, 6.4 +/- 0.6%. We suggest that the fibroblasts are more responsive to stretch because of their more highly developed actin cytoskeleton. PMID:11347703

  13. [Dark metabolism of acetate in Rhodospirillum rubrum cells, grown under photoheterotropic conditions].

    PubMed

    Berg, I A; Krasil'nikova, E N; Ivanovskiĭ, R N

    2000-01-01

    The mechanism of the dark assimilation of acetate in the photoheterotrophically grown nonsulfur bacterium Rhodospirillum rubrum was studied. Both in the light and in the dark, acetate assimilation in Rsp. rubrum cells, which lack the glyoxylate pathway, was accompanied by the excretion of glyoxylate into the growth medium. The assimilation of propionate was accompanied by the excretion of pyruvate. Acetate assimilation was found to be stimulated by bicarbonate, pyruvate, the C4-dicarboxylic acids of the Krebs cycle, and glyoxylate, but not by propionate. These data implied that the citramalate (CM) cycle in Rsp. rubrum cells grown aerobically in the dark can function as an anaplerotic pathway. This supposition was confirmed by respiration measurements. The respiration of cells oxidizing acetate depended on the presence of CO2 in the medium. The fact that the intermediates of the CM cycle (citramalate and mesaconate) markedly inhibited acetate assimilation but had almost no effect on cell respiration indicative that citramalate and mesaconate are intermediates of the acetate assimilation pathway. The inhibition of acetate assimilation and cell respiration by itaconate was due to its inhibitory effect on propionyl-CoA carboxylase, an enzyme of the CM cycle. The addition of 5 mM itaconate to extracts of Rsp. rubrum cells inhibited the activity of this enzyme by 85%. The data obtained suggest that the CM cycle continues to function in Rsp. rubrum cells that have been grown anaerobically in the light and then transferred to the dark and incubated aerobically. PMID:10808482

  14. Commissioning and initial stereotactic ablative radiotherapy experience with Vero.

    PubMed

    Solberg, Timothy D; Medin, Paul M; Ramirez, Ezequiel; Ding, Chuxiong; Foster, Ryan D; Yordy, John

    2014-01-01

    The purpose of this study is to describe the comprehensive commissioning process and initial clinical performance of the Vero linear accelerator, a new radiotherapy device recently installed at UT Southwestern Medical Center specifically developed for delivery of image-guided stereotactic ablative radiotherapy (SABR). The Vero system utilizes a ring gantry to integrate a beam delivery platform with image guidance systems. The ring is capable of rotating ± 60° about the vertical axis to facilitate noncoplanar beam arrangements ideal for SABR delivery. The beam delivery platform consists of a 6 MV C-band linac with a 60 leaf MLC projecting a maximum field size of 15 × 15 cm² at isocenter. The Vero planning and delivery systems support a range of treatment techniques, including fixed beam conformal, dynamic conformal arcs, fixed gantry IMRT in either SMLC (step-and-shoot) or DMLC (dynamic) delivery, and hybrid arcs, which combines dynamic conformal arcs and fixed beam IMRT delivery. The accelerator and treatment head are mounted on a gimbal mechanism that allows the linac and MLC to pivot in two dimensions for tumor tracking. Two orthogonal kV imaging subsystems built into the ring facilitate both stereoscopic and volumetric (CBCT) image guidance. The system is also equipped with an always-active electronic portal imaging device (EPID). We present our commissioning process and initial clinical experience focusing on SABR applications with the Vero, including: (1) beam data acquisition; (2) dosimetric commissioning of the treatment planning system, including evaluation of a Monte Carlo algorithm in a specially-designed anthropomorphic thorax phantom; (3) validation using the Radiological Physics Center thorax, head and neck (IMRT), and spine credentialing phantoms; (4) end-to-end evaluation of IGRT localization accuracy; (5) ongoing system performance, including isocenter stability; and (6) clinical SABR applications. PMID:24710458

  15. Modifications of the cell wall of yeasts grown on hexadecane and under starvation conditions.

    PubMed

    Dmitriev, Vladimir V; Crowley, David E; Zvonarev, Anton N; Rusakova, Tatiana G; Negri, Maria C; Kolesnikova, Svetlana A

    2016-02-01

    Electron-microscopic examinations have demonstrated local modifications in the cell wall of the yeast Candida maltosa grown on hexadecane. In our earlier studies, these modified sites, observed in other yeasts grown on oil hydrocarbons, were conventionally called 'canals'. The biochemical and cytochemical studies of C. maltosa have revealed a correlation between the formation of 'canals' and decrease in the amount of cell wall polysaccharides, glucan and mannan. The ultrathin sections and surface replicas have shown that the 'canals' are destroyed by pronase, thus indicating that a significant proportion of their content is represented by proteins. This finding was compatible with our earlier data on the localization of oxidative enzymes in 'canals' and possible participation of the 'canals' in the primary oxidation of hydrocarbons. A completely unexpected and intriguing phenomenon has been the appearance of 'canals' in the yeast C. maltosa under starvation conditions. Unlike the yeasts grown on hexadecane, mannan almost disappears in starving cells, while the quantity of glucan first decreases and then is restored to its initial level. The role of 'canals' in starving cells is as yet unclear; it is assumed that they acquire exoenzymes involved in the utilization of products of cell lysis in the starving population. In the future, 'canals' of starving cells will be studied in connection with their possible participation in apoptosis. PMID:26833628

  16. Impedance analysis of different cell monolayers grown on gold-film electrodes.

    PubMed

    Reiss, Bjoern; Wegener, Joachim

    2015-08-01

    Impedance analysis of mammalian cells grown on planar film electrodes provides a label-free, non-invasive and unbiased observation of cell-based assays addressing the biological response to drugs, toxins or stressors in general. Whereas the time course of the measured impedance at one particular frequency has been used a lot for quantitative monitoring, in-depth analysis of the frequency-dependent impedance spectra is rarely performed. This study summarizes and validates the existing model for spectral analysis by applying it to eight different cell types from different mammalian tissues. Model parameters correctly predict the functional and/or structural properties of the individual cells under study. PMID:26737923

  17. Homojunction GaAs solar cells grown by close space vapor transport

    SciTech Connect

    Boucher, Jason W.; Ritenour, Andrew J.; Greenaway, Ann L.; Aloni, Shaul; Boettcher, Shannon W.

    2014-06-08

    We report on the first pn junction solar cells grown by homoepitaxy of GaAs using close space vapor transport (CSVT). Cells were grown both on commercial wafer substrates and on a CSVT absorber film, and had efficiencies reaching 8.1%, open circuit voltages reaching 909 mV, and internal quantum efficiency of 90%. The performance of these cells is partly limited by the electron diffusion lengths in the wafer substrates, as evidenced by the improved peak internal quantum efficiency in devices fabricated on a CSVT absorber film. Unoptimized highly-doped n-type emitters also limit the photocurrent, indicating that thinner emitters with reduced doping, and ultimately wider band gap window or surface passivation layers, are required to increase the efficiency.

  18. Effects of method of detachment on electrophoretic mobility of mammalian cells grown in monolayer culture

    NASA Technical Reports Server (NTRS)

    Plank, L. D.; Kunze, M. E.; Todd, P. W.

    1985-01-01

    A variety of proteolytic and micolytic enzumes, mechanical procedures, and changes in the ionic environment, especially Ca chelation, are used for dispersal of monolayer grown cells. If either chelating agents or mechanical dispersion are used alone, the cell yield is often low and suspensions of single cells are difficult to obtain. Confluent monolayers treated with EDTA tend to be released from their surfaces in sheets, and clumps of cells remain even after further incubation in EDTA. Crude trypsin is the most popular dispersal agent and is known to contain a variety of contaminating enzymes which contribute to the dispersal of cells. A variety of cell injuries resulting from the activity of proteolytic enzymes are reported. It is shown that crystalline trypsin is least harmful to cell integrity as judged by trypan blue uptake.

  19. Solution-Grown Monocrystalline Hybrid Perovskite Films for Hole-Transporter-Free Solar Cells.

    PubMed

    Peng, Wei; Wang, Lingfei; Murali, Banavoth; Ho, Kang-Ting; Bera, Ashok; Cho, Namchul; Kang, Chen-Fang; Burlakov, Victor M; Pan, Jun; Sinatra, Lutfan; Ma, Chun; Xu, Wei; Shi, Dong; Alarousu, Erkki; Goriely, Alain; He, Jr-Hau; Mohammed, Omar F; Wu, Tom; Bakr, Osman M

    2016-05-01

    High-quality perovskite monocrystalline films are successfully grown through cavitation-triggered asymmetric crystallization. These films enable a simple cell structure, ITO/CH3 NH3 PbBr3 /Au, with near 100% internal quantum efficiency, promising power conversion efficiencies (PCEs) >5%, and superior stability for prototype cells. Furthermore, the monocrystalline devices using a hole-transporter-free structure yield PCEs ≈6.5%, the highest among other similar-structured CH3 NH3 PbBr3 solar cells to date. PMID:26931100

  20. Growth and radiation response of cells grown in macroporous gelatin microcarriers (CultiSpher-G).

    PubMed Central

    Rasey, J. S.; Cornwell, M. M.; Maurer, B. J.; Boyles, D. J.; Hofstrand, P.; Chin, L.; Cerveny, C.

    1996-01-01

    Four cell lines have been cultured in macroporous gelatin microcarrier beads (CultiSpher-G) to test this as a new model of three-dimensional cell growth for use in experimental cancer therapy. A549, KB 3-1, KB 8-5 and V79 cells were successfully grown in CultiSphers, albeit with longer doubling times than observed for the respective cell type in monolayer cultures. MTT staining and histology demonstrated three-dimensional contact of cells in the microcarriers. A549 cells populated the microcarriers more densely than KB 3-1 cells, and with both cell types there is bead-to-bead variation in occupancy by cells. [3H]TdR autoradiography reveals labelled cells throughout A549 and KB 3-1 CultiSphers, with no proliferation gradient from edge to centre. Central necrosis has not been observed. A549 cells but not KB 3-1 cells demonstrated a radiation contact effect (i.e. resistance) when irradiated in CultiSphers, compared with monolayers. We conclude that CultiSphers may be a useful model for three-dimensional growth and cell contact when investigators want to investigate these phenomena without the microenvironmental gradients of spheroids. Images Figure 1 PMID:8763852

  1. Lithium Induces ER Stress and N-Glycan Modification in Galactose-Grown Jurkat Cells

    PubMed Central

    Kátai, Emese; Yahiro, Rikki K. K.; Poór, Viktor S.; Montskó, Gergely; Zrínyi, Zita; Kovács, Gábor L.; Miseta, Attila

    2013-01-01

    We previously reported that lithium had a significant impact on Ca2+ regulation and induced unfolded protein response (UPR) in yeast cells grown on galactose due to inhibition of phosphoglucomutase (PGM), however the exact mechanism has not been established yet. In this study, we analysed lithium's effect in galactose-fed cells to clarify whether these ER-related changes are the result of a relative hypoglycemic state. Furthermore, we investigated whether the alterations in galactose metabolism impact protein post-translational modifications. Thus, Jurkat cells were incubated in glucose or galactose containing media with or without lithium treatment. We found that galactose-fed and lithium treated cells showed better survivability than fasting cells. We also found higher UDP-Hexose and glycogen levels in these cells compared to fasting cells. On the other hand, the UPR (X-box binding protein 1 mRNA levels) of galactose-fed and lithium treated cells was even greater than in fasting cells. We also found increased amount of proteins that contained N-linked N-acetyl-glucosamine, similar to what was reported in fasting cells by a recent study. Our results demonstrate that lithium treatment of galactose-fed cells can induce stress responses similar to hypoglycemia, however cell survival is still secured by alternative pathways. We propose that clarifying this process might be an important addition toward the better understanding of the molecular mechanisms that regulate ER-associated stress response. PMID:23894652

  2. Epitaxial Crystal Silicon Absorber Layers and Solar Cells Grown at 1.8 Microns per Minute

    SciTech Connect

    Bobela, D. C.; Teplin, C. W.; Young, D. L.; Branz, H. M.; Stradins, P.

    2011-01-01

    We have grown device-quality epitaxial silicon thin films at growth rates up to 1.85 {micro}m/min, using hot-wire chemical vapor deposition from silane, at substrate temperatures below 750 C. At these rates, which are more than 30 times faster than those used by the amorphous and nanocrystalline Si industry, capital costs for large-scale solar cell production would be dramatically reduced, even for cell absorber layers up to 10 {micro}m thick. We achieved high growth rates by optimizing the three key parameters: silane flow, depletion, and filament geometry, based on our model developed earlier. Hydrogen coverage of the filament surface likely limits silane decomposition and growth rate at high system pressures. No considerable deterioration in PV device performance is observed when grown at high rate, provided that the epitaxial growth is initiated at low rate. A simple mesa device structure (wafer/epi Si/a-Si(i)/a-Si:H(p)/ITO) with a 2.3 {micro}m thick epitaxial silicon absorber layer was grown at 0.7 {micro}m/min. The finished device had an open-circuit voltage of 0.424 V without hydrogenation treatment.

  3. Aging impairs osteoblast differentiation of mesenchymal stem cells grown on titanium by favoring adipogenesis

    PubMed Central

    ABUNA, Rodrigo Paolo Flores; STRINGHETTA-GARCIA, Camila Tami; FIORI, Leonardo Pimentel; DORNELLES, Rita Cassia Menegati; ROSA, Adalberto Luiz; BELOTI, Marcio Mateus

    2016-01-01

    ABSTRACT Aging negatively affects bone/titanium implant interactions. Our hypothesis is that the unbalance between osteogenesis and adipogenesis induced by aging may be involved in this phenomenon. Objective We investigated the osteoblast and adipocyte differentiation of mesenchymal stem cells (MSCs) from young and aged rats cultured on Ti. Material and Methods Bone marrow MSCs derived from 1-month and 21-month rats were cultured on Ti discs under osteogenic conditions for periods of up to 21 days and osteoblast and adipocyte markers were evaluated. Results Cell proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization and gene expression of RUNX2, osterix, ALP, bone sialoprotein, osteopontin, and osteocalcin were reduced in cultures of 21-month rats compared with 1-month rats grown on Ti. Gene expression of PPAR-γ , adipocyte protein 2, and resistin and lipid accumulation were increased in cultures of 21-month rats compared with 1-month rats grown on the same conditions. Conclusions These results indicate that the lower osteogenic potential of MSCs derived from aged rats compared with young rats goes along with the higher adipogenic potential in cultures grown on Ti surface. This unbalance between osteoblast and adipocyte differentiation should be considered in dental implant therapy to the elderly population. PMID:27556209

  4. Cyclic-radiation response of murine fibrosarcoma cells grown as pulmonary nodules

    SciTech Connect

    Grdina, D.J.; Hunter, N.

    1982-10-01

    The radiation age response of murine fibrosarcoma (FSa) cells grown as pulmonary nodules in C/sub 3/Hf/Kam mice was determined. FSa cells were irradiated in vivo either with 10 Gy as 14 day-old lung tumors (i.e., artificial macrometastases) prior to cell separation or with 5 Gy as single cells trapped in the lungs of recipient mice (i.e., artificial micrometastases) following cell separation and synchronization by centrifugal elutriation. Flow microfluorometry (FMF) was used to determine cell-cycle parameters and the relative synchrony of the separated populations, as well as the percent contamination of normal diploid cells in each of the tumor cell populations. Tumor populations containing up to 90% G/sub 1/, 60% S-, and 75% G/sub 2/+M-phase tumor cells were obtained. Cell clonogenicity, determined using a lung colony assay, ranged from 0.7 to 6% for control FSa cells from the various elutriator fractions. The radiation sensitivity of these separated cell populations varied by a factor of 6, regardless of whether the cells were irradiated as artificial micro or macro-metastases. In each experiment, tumor populations most enriched in s-phase cells exhibited the greatest radiation sensitivity. To confirm that these populations were highly enriched in S-phase cells and to demonstrate that they were more radiosensitive than FSa cells in other parts of the cell cycle, the elutriated tumor populations were exposed to either suicide labeling by high specific activity tritiated thymidine or hydroxyurea. The resultant age response curves were qualitatively similar to those obtained following irradiation and reflected the S-phase sensitivity of FSa cells to these agents.

  5. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    NASA Astrophysics Data System (ADS)

    Li, Wei; Varlamov, Sergey; Xue, Chaowei

    2014-09-01

    This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, Voc and Jsc than the one on the seed layer without RTA treatment.

  6. Cyclic-radiation response of murine fibrosarcoma cells grown as pulmonary nodules

    SciTech Connect

    Grdina, D.J.; Hunter, N.

    1982-10-01

    The radiation age response of murine fibrosarcoma (FSa) cells grown as pulmonary nudules in C/sub 3/Hf/Kam mice was determined. FSa cells were irradiated in vivo either with 10 Gy as 14 day-old lung tumors (i.e., artifical micrometastases) following cell separation and synchronization by centrifugal elutriation. Flow microfluorometry (FMF) was used to determine cell-cycle parameters and the relative synchrony of the separated populations, as well as the percent contamination of normal diploid cells in each of the tumor cells populations. Tumor populations containing up to 90% G/sub 1/-, 60% S-, and 75% G/sub 2/+M-phase tumor cells were obtained. Cell clonogenicity, determined using a lung colony assay, ranged from 0.7 to 6% for control FSa cells from the various elutriator fractions. The radiation sensitivity of these separated cell populations varied by a factor of 6, regardless of whether the cells were irradiated as artifical micro or macro-metastases. In each experiment, tumor population most enriched in S-phase cells exhibited the greatest radiation sensitivity. To confirm that these populations were highly enriched in S-phase cells and to demonstrate that they were more radiosensitive than FSa cells in other parts of the cell cycle, the elutriated tumor population were exposed to either suicide labeling by high specific activity tritated thymidine or hydroxyurea. The resultant age response curves were qualitatively similar to those obtained following irradiation and reflected the S-phase sensitivity of FSa cells to these agents.

  7. 33 CFR 110.73b - Indian River at Vero Beach, Fla.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Indian River at Vero Beach, Fla. 110.73b Section 110.73b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.73b Indian River at Vero Beach, Fla. (a)...

  8. Phase III Clinical Trials Comparing the Immunogenicity and Safety of the Vero Cell-Derived Japanese Encephalitis Vaccine Encevac with Those of Mouse Brain-Derived Vaccine by Using the Beijing-1 Strain

    PubMed Central

    Miyazaki, Chiaki; Okada, Kenji; Ozaki, Takao; Hirose, Mizuo; Iribe, Kaneshige; Ishikawa, Yuji; Togashi, Takehiro; Ueda, Kohji

    2014-01-01

    The immunogenicity and safety of an inactivated cell culture Japanese encephalitis vaccine (CC-JEV) were compared with those of an inactivated mouse brain-derived Japanese encephalitis vaccine (MB-JEV) in phase III clinical multicenter trials conducted in children. The vaccines contain the same Japanese encephalitis virus strain, the Beijing-1 strain. Two independent clinical trials (trials 1 and 2) were conducted. Trial 1 was conducted in 468 healthy children. Each subject was injected with 17 μg per dose of either CC-JEV or MB-JEV, and the immunogenicity and safety of the vaccines were investigated. Trial 1 showed that CC-JEV was more immunogenic and reactive than MB-JEV at the same dose. Therefore, to adjust the immunogenicity of CC-JEV to that of MB-JEV, a vaccine that has had a good track record regarding its efficacy for a long time, trial 2 was conducted in 484 healthy children. To improve the stability, CC-JEV was converted from a liquid type to a freeze-dried type of vaccine. Each subject was injected subcutaneously with either 4 μg per dose of CC-JEV, 8 μg per dose of CC-JEV, or 17 μg per dose of MB-JEV twice, at an interval of 2 to 4 weeks, followed by an additional booster immunization 1 to 15 months after the primary immunization. Based on the results of trial 2, 4 μg per dose of the freeze-dried CC-JEV (under the label Encevac) was selected as a substitute for the MB-JEV. Encevac was approved and launched in 2011 and has since been in use as a 2nd-generation Japanese encephalitis vaccine in Japan. (These studies have been registered at the JapicCTI under registration no. JapicCTI-132063 and JapicCTI-080586 for trials 1 and 2, respectively.) PMID:24334689

  9. MDR-related properties of K 562 cells grown in two different culture media.

    PubMed

    Ferrand, V L; Chauvet, M M; Dell'Amico, M H; Tsuruo, T; Hirn, M H; Bourdeaux, M J

    1996-01-01

    Using a synthetic substitute, Ultroser HY, for fetal bovine serum to supplement a classical RPMI 1640 culture medium produced changes in the properties of sensitive and of multidrug-resistant K 562 cells. Though no morphological changes were found, a statistically significant decrease in doubling-time was noted. Plasma membranes were more rigid, as reflected by an increase in the order parameter values. Adriamycin cytotoxicity was decreased, as shown by an increase in IC 50 values. The THP-adriamycin uptake, monitored by fluorimetry, was diminished even when the revertant agent verapamil was added. Moreover, the apparent number of Pgp 170 molecules per cell was lower for resistant cells grown with Ultroser HY. Thus Pgp 170 was not involved in the MDR increase induced by Ultroser HY. In conclusion, it must be kept in mind that environmental factors such as media chemical composition influence the MDR phenomenon and that environmental factors may also influence the MDR phenomenon in clinical situations. PMID:9042237

  10. Mesenchymal traits are selected along with stem features in breast cancer cells grown as mammospheres

    PubMed Central

    Borgna, Silvia; Armellin, Michela; di Gennaro, Alessandra; Maestro, Roberta; Santarosa, Manuela

    2012-01-01

    Increasing evidence indicates that invasive properties of breast cancers rely on gain of mesenchymal and stem features, which has suggested that the dual targeting of these phenotypes may represent an appealing therapeutic strategy. It is known that the fraction of stem cells can be enriched by culturing breast cancer cells as mammospheres (MS), but whether these pro-stem conditions favor also the expansion of cells provided of mesenchymal features is still undefined. In the attempt to shed light on this issue, we compared the phenotypes of a panel of 10 breast cancer cell lines representative of distinct subtypes (luminal, HER2-positive, basal-like and claudin-low), grown in adherent conditions and as mammospheres. Under MS-proficient conditions, the increment in the fraction of stem-like cells was associated to upregulation of the mesenchymal marker Vimentin and downregulation of the epithelial markers expressed by luminal cells (E-cadherin, KRT18, KRT19, ESR1). Luminal cells tended also to upregulate the myoepithelial marker CD10. Taken together, our data indicate that MS-proficient conditions do favor mesenchymal/myoepithelial features, and indicate that the use of mammospheres as an in vitro tumor model may efficiently allow the exploitation of therapeutic approaches aimed at targeting aggressive tumors that have undergone epithelial-to-mesenchymal transition. PMID:23095640

  11. Proliferation and Differentiation Potential of Human Adipose-Derived Stem Cells Grown on Chitosan Hydrogel

    PubMed Central

    Debnath, Tanya; Ghosh, Sutapa; Potlapuvu, Usha Shalini; Kona, Lakshmi; Kamaraju, Suguna Ratnakar; Sarkar, Suprabhat; Gaddam, Sumanlatha; Chelluri, Lakshmi Kiran

    2015-01-01

    Applied tissue engineering in regenerative medicine warrants our enhanced understanding of the biomaterials and its function. The aim of this study was to evaluate the proliferation and differentiation potential of human adipose-derived stem cells (hADSCs) grown on chitosan hydrogel. The stability of this hydrogel is pH-dependent and its swelling property is pivotal in providing a favorable matrix for cell growth. The study utilized an economical method of cross linking the chitosan with 0.5% glutaraldehyde. Following the isolation of hADSCs from omentum tissue, these cells were cultured and characterized on chitosan hydrogel. Subsequent assays that were performed included JC-1 staining for the mitochondrial integrity as a surrogate marker for viability, cell proliferation and growth kinetics by MTT assay, lineage specific differentiation under two-dimensional culture conditions. Confocal imaging, scanning electron microscopy (SEM), and flow cytometry were used to evaluate these assays. The study revealed that chitosan hydrogel promotes cell proliferation coupled with > 90% cell viability. Cytotoxicity assays demonstrated safety profile. Furthermore, glutaraldehyde cross linked chitosan showed < 5% cytotoxicity, thus serving as a scaffold and facilitating the expansion and differentiation of hADSCs across endoderm, ectoderm and mesoderm lineages. Additional functionalities can be added to this hydrogel, particularly those that regulate stem cell fate. PMID:25746846

  12. Human norovirus infection of caco-2 cells grown as a three-dimensional tissue structure.

    PubMed

    Straub, Timothy M; Bartholomew, Rachel A; Valdez, Catherine O; Valentine, Nancy B; Dohnalkova, Alice; Ozanich, Richard M; Bruckner-Lea, Cynthia J; Call, Douglas R

    2011-06-01

    Human norovirus (hNoV) infectivity was studied using a three-dimensional model of large intestinal epithelium. Large intestine Caco-2 cells were grown in rotating wall vessel bioreactors for 18-21 days at 37 degrees C and then transferred to 24-well tissue culture plates where they were infected with GI.1 and GII.4 human noroviruses collected from human challenge trials and various outbreak settings, respectively. Compared with uninfected cells, transmission micrographs of norovirus-infected cells displayed evidence of shortening or total loss of apical microvilli, and vacuolization. Quantitative reverse transcription real-time PCR (qRT-PCR) indicated an approximate 2-3 log10 increase in viral RNA copies for the infected cells. A passage experiment examined both the ability for continued viral RNA and viral antigen detection. In the passaged samples 1.01x10(6) copies ml(-1) were detected by qRT-PCR. Immune electron microscopy using primary antibody to hNoV GI.1 capsids in conjunction with 6 nm gold-labelled secondary antibodies was performed on crude cellular lysates. Localization of antibody was observed in infected but not for uninfected cells. Our present findings, coupled with earlier work with the three-dimensional small intestinal INT407 model, demonstrate the utility of 3-D cell culture methods to develop infectivity assays for enteric viruses that do not readily infect mammalian cell cultures. PMID:21942189

  13. Single and multijunction space solar cells grown by organometallic vapor phase epitaxy (OM-VPE)

    SciTech Connect

    Borden, P.G.; Gregory, P.E.; Larue, R.A.; Ludowise, M.J.

    1982-08-01

    Organometallic Vapor Phase Epitaxy (OM-VPE) is a versatile technique for growing III-V compound semiconductor solar cells. It has good uniformity and morphology, control that allows growth of extremely thin layers, and is a technique readily automated. The vehicle for the present discussion is a metal interconnected cascade (MIC/sup 2/) solar cell that has achieved 16.6% AM0 and 22% AM3 efficiency (uncorrected for 14% grid coverage). These are the best results reported to date for a cascade solar cell. Features include a 9-layer epitaxial structure, the thinnest of which is less than 1000 thick, a high-efficiency 30% AlGaAs top cell only 1.5 microns thick, a GaAs bottom cell that has survived the 780/sup 0/C, 20-minute top cell growth, and process yields greater than 4 cm/sup 2/ per wafer. The paper describes the cell design requirements, how it was grown by OM-VPE, and performance results.

  14. Resistance of Lung Cancer Cells Grown as Multicellular Tumour Spheroids to Zinc Sulfophthalocyanine Photosensitization

    PubMed Central

    Manoto, Sello Lebohang; Houreld, Nicolette Nadene; Abrahamse, Heidi

    2015-01-01

    Photodynamic therapy (PDT) is phototherapeutic modality used in the treatment of neoplastic and non-neoplastic diseases. The photochemical interaction of light, photosensitizer (PS) and molecular oxygen produces singlet oxygen which induces cell death. Zinc sulfophthalocyanine (ZnPcSmix) has been shown to be effective in A549 monolayers, multicellular tumor spheroids (MCTSs) (250 µm) and not on MCTSs with a size of 500 µm. A549 cells used in this study were grown as MCTSs to a size of 500 µm in order to determine their susceptibility to PDT. ZnPcSmix distribution in MCTSs and nuclear morphology was determined using a fluorescent microscope. Changes in cellular responses were evaluated using cell morphology, viability, proliferation, cytotoxicity, cell death analysis and mitochondrial membrane potential. Untreated MCTSs, showed no changes in cellular morphology, proliferation, cytotoxicity and nuclear morphology. Photoactivated ZnPcSmix also showed no changes in cellular morphology and nuclear morphology. However, photoactivated ZnPcSmix resulted in a significant dose dependant decrease in viability and proliferation as well as an increase in cell membrane damage in MCTSs over time. ZnPcSmix photosensitization induces apoptotic cell death in MCTSs with a size of 500 µm and more resistantance when compared to monolayer cells and MCTSs with a size of 250 µm. PMID:25950764

  15. Characterization of Epitaxial Film Silicon Solar Cells Grown on Seeded Display Glass: Preprint

    SciTech Connect

    Young, D. L.; Grover, S.; Teplin, C.; Stradins, P.; LaSalvia, V.; Chuang, T. K.; Couillard, J. G.; Branz, H. M.

    2012-06-01

    We report characterizations of epitaxial film crystal silicon (c-Si) solar cells with open-circuit voltages (Voc) above 560 mV. The 2-um absorber cells are grown by low-temperature (<750 degrees C) hot-wire CVD (HWCVD) on Corning EAGLE XG display glass coated with a layer-transferred (LT) Si seed. The high Voc is a result of low-defect epitaxial Si (epi-Si) growth and effective hydrogen passivation of defects. The quality of HWCVD epitaxial growth on seeded glass substrates depends on the crystallographic quality of the seed and the morphology of the epitaxial growth surface. Heterojunction devices consist of glass/c-Si LT seed/ epi n+ Si:P/epi n- Si:P/intrinsic a-Si:H/p+ a-Si:H/ITO. Similar devices grown on electronically 'dead' n+ wafers have given Voc {approx}630 mV and {approx}8% efficiency with no light trapping features. Here we study the effects of the seed surface polish on epi-Si quality, how hydrogenation influences the device character, and the dominant junction transport physics.

  16. Electron-cytochemical study of Ca2+ in cotyledon cells of soybean seedlings grown in microgravity

    NASA Technical Reports Server (NTRS)

    Nedukha, O.; Brown, C. S.; Kordyum, E.; Piastuch, W. C.; Guikema, J. A. (Principal Investigator)

    1999-01-01

    Microgravity and horizontal clinorotation are known to cause the rearrangement of the structural-functional organization of plant cells, leading to accelerated aging. Altered gravity conditions resulted in an increase in the droplets volume in cells and the destruction of chloroplast structure in Arabidopsis thaliana plants, an enhancement of cytosolic autophagaous processes, an increase in the respiration rate and a greater number of multimolecular forms of succinate- and malate dehydrogenases in cells of the Funaria hygrometrica protonema and Chlorella vulgaris, and changes in calcium balance of cells. Because ethylene is known to be involved in cell aging and microgravity appears to speed the process, and because soybean seedlings grown in space produce higher ethylene levels we asked: 1) does an acceleration of soybean cotyledon cell development and aging occur in microgravity? 2) what roles do Ca2+ ions and the enhanced ethylene level play in these events? Therefore, the goal of our investigation was to examine of the interaction of microgravity and ethylene on the localization of Ca2+ in cotyledon mesophyll of soybean seedlings.

  17. Stimulation of Cell Elongation by Tetraploidy in Hypocotyls of Dark-Grown Arabidopsis Seedlings

    PubMed Central

    Narukawa, Hideki; Yokoyama, Ryusuke; Komaki, Shinichiro; Sugimoto, Keiko; Nishitani, Kazuhiko

    2015-01-01

    Plant size is largely determined by the size of individual cells. A number of studies showed a link between ploidy and cell size in land plants, but this link remains controversial. In this study, post-germination growth, which occurs entirely by cell elongation, was examined in diploid and autotetraploid hypocotyls of Arabidopsis thaliana (L.) Heynh. Final hypocotyl length was longer in tetraploid plants than in diploid plants, particularly when seedlings were grown in the dark. The longer hypocotyl in the tetraploid seedlings developed as a result of enhanced cell elongation rather than by an increase in cell number. DNA microarray analysis showed that genes involved in the transport of cuticle precursors were downregulated in a defined region of the tetraploid hypocotyl when compared to the diploid hypocotyl. Cuticle permeability, as assessed by toluidine-blue staining, and cuticular structure, as visualized by electron microscopy, were altered in tetraploid plants. Taken together, these data indicate that promotion of cell elongation is responsible for ploidy-dependent size determination in the Arabidopsis hypocotyl, and that this process is directly or indirectly related to cuticular function. PMID:26244498

  18. Rapid differentiation of NT2 cells in Sertoli-NT2 cell tissue constructs grown in the rotating wall bioreactor.

    PubMed

    Saporta, Samuel; Willing, Alison E; Shamekh, Rania; Bickford, Paula; Paredes, Daniel; Cameron, Don F

    2004-12-15

    Cell replacement therapy is of great interest as a long-term treatment of neurodegenerative diseases such as Parkinson's disease (PD). We have previously shown that Sertoli cells (SC) provide neurotrophic support to transplants of dopaminergic fetal neurons and NT2N neurons, derived from the human clonal precursors cell line NTera2/D1 (NT2), which differentiate into dopaminergic NT2N neurons when exposed to retinoic acid. We have created SC-NT2 cell tissue constructs cultured in the high aspect ratio vessel (HARV) rotating wall bioreactor. Sertoli cells, NT2, and SC plus NT2 cells combined in starting ratios of 1:1, 1:2, 1:4 and 1:8 were cultured in the HARV in DMEM with 10% fetal bovine serum and 1% growth factor reduced Matrigel for 3 days, without retinoic acid. Conventional, non-HARV, cultures grown in the same culture medium were used as controls. The presence of tyrosine hydroxylase (TH) was assessed in all culture conditions. Sertoli-neuron-aggregated-cell (SNAC) tissue constructs grown at starting ratios of 1:1 to 1:4 contained a significant amount of TH after 3 days of culture in the HARV. No TH was detected in SC HARV cultures, or SC, NT2 or SC-NT2 conventional co-cultures. Quantitative stereology of immunolabled 1:4 SNAC revealed that approximately 9% of NT2 cells differentiate into TH-positive (TH+) NT2N neurons after 3 days of culture in the HARV, without retinoic acid. SNAC tissue constructs also released dopamine (DA) when stimulated with KCl, suggesting that TH-positive NT2N neurons in the SNAC adopted a functional dopaminergic phenotype. SNAC tissue constructs may be an important source of dopaminergic neurons for neuronal transplantation. PMID:15561470

  19. Highly parallel introduction of nucleic acids into mammalian cells grown in microwell arrays

    PubMed Central

    Jain, Tilak; McBride, Ryan; Head, Steven; Saez, Enrique

    2010-01-01

    High-throughput cell-based screens of genome-size collections of cDNAs and siRNAs have become a powerful tool to annotate the mammalian genome, enabling the discovery of novel genes associated with normal cellular processes and pathogenic states, and the unraveling of genetic networks and signaling pathways in a systems biology approach. However, the capital expenses and the cost of reagents necessary to perform such large screens have limited application of this technology. Efforts to miniaturize the screening process have centered on the development of cellular microarrays created on microscope slides that use chemical means to introduce exogenous genetic material into mammalian cells. While this work has demonstrated the feasibility of screening in very small formats, the use of chemical transfection reagents (effective only in a subset of cell lines and not on primary cells) and the lack of defined borders between cells grown in adjacent microspots containing different genetic material (to prevent cell migration and to aid spot location recognition during imaging and phenotype deconvolution) have hampered the spread of this screening technology. Here, we describe proof-of-principles experiments to circumvent these drawbacks. We have created microwell arrays on an electroporation-ready transparent substrate and established procedures to achieve highly efficient parallel introduction of exogenous molecules into human cell lines and primary mouse macrophages. The microwells confine cells and offer multiple advantages during imaging and phenotype analysis. We have also developed a simple method to load this 484-microwell array with libraries of nucleic acids using a standard microarrayer. These advances can be elaborated upon to form the basis of a miniaturized high-throughput functional genomics screening platform to carry out genome-size screens in a variety of mammalian cells that may eventually become a mainstream tool for life science research. PMID:20024036

  20. Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space.

    PubMed

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki; Kotake, Toshihisa; Yamazaki, Takashi; Higashibata, Akira; Ishioka, Noriaki; Shimazu, Toru; Fukui, Keiji; Osada, Ikuko; Kasahara, Haruo; Kamada, Motoshi

    2015-01-01

    Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA) and p-coumaric acid, but it suppressed increases in diferulic acid (DFA) isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions. PMID:26378793

  1. Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space

    PubMed Central

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki; Kotake, Toshihisa; Yamazaki, Takashi; Higashibata, Akira; Ishioka, Noriaki; Shimazu, Toru; Fukui, Keiji; Osada, Ikuko; Kasahara, Haruo; Kamada, Motoshi

    2015-01-01

    Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA) and p-coumaric acid, but it suppressed increases in diferulic acid (DFA) isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions. PMID:26378793

  2. Xylem Development and Cell Wall Changes of Soybean Seedlings Grown in Space

    PubMed Central

    de Micco, Veronica; Aronne, Giovanna; Joseleau, Jean-Paul; Ruel, Katia

    2008-01-01

    Background and Aims Plants growing in altered gravity conditions encounter changes in vascular development and cell wall deposition. The aim of this study was to investigate xylem anatomy and arrangement of cellulose microfibrils in vessel walls of different organs of soybean seedlings grown in Space. Methods Seeds germinated and seedlings grew for 5 d in Space during the Foton-M2 mission. The environmental conditions, other than gravity, of the ground control repeated those experienced in orbit. The seedlings developed in space were compared with those of the control test on the basis of numerous anatomical and ultrastructural parameters such as number of veins, size and shape of vessel lumens, thickness of cell walls and deposition of cellulose microfibrils. Key Results Observations made with light, fluorescence and transmission electron microscopy, together with the quantification of the structural features through digital image analysis, showed that the alterations due to microgravity do not occur at the same level in the various organs of soybean seedlings. The modifications induced by microgravity or by the indirect effect of space-flight conditions, became conspicuous only in developing vessels at the ultrastructural level. The results suggested that the orientation of microfibrils and their assembly in developing vessels are perturbed by microgravity at the beginning of wall deposition, while they are still able to orient and arrange in thicker and ordered structures at later stages of secondary wall deposition. Conclusions The process of proper cell-wall building, although not prevented, is perturbed in Space at the early stage of development. This would explain the almost unaltered anatomy of mature structures, accompanied by a slower growth observed in seedlings grown in Space than on Earth. PMID:18252765

  3. Spheroid formation and enhanced cardiomyogenic potential of adipose-derived stem cells grown on chitosan.

    PubMed

    Liu, Bing-Hsien; Yeh, Hsi-Yi; Lin, Yu-Chun; Wang, Min-Hsiung; Chen, David C; Lee, Bo-Hua; Hsu, Shan-Hui

    2013-02-01

    Mesenchymal stem cells may differentiate into cardiomyocytes and participate in local tissue repair after heart injury. In the current study, rat adipose-derived adult stem cells (ASCs) grown on chitosan membranes were observed to form cell spheroids after 3 days. The cell seeding density and surface modification of chitosan with Arg-Gly-Asp-containing peptide had an influence on the sizes of ASC spheroids. In the absence of induction, these spheroids showed an increased level of cardiac marker gene expression (Gata4, Nkx2-5, Myh6, and Tnnt2) more than 20-fold versus cells on the tissue culture polystyrene (TCPS) dish. Induction by 5-azacytidine or p38 MAP kinase inhibitor (SB202190) did not further increase the cardiac marker gene expression of these spheroids. Moreover, the enhanced cardiomyogenic potential of the spheroids was highly associated with the chitosan substrates. When ASC spheroids were plated onto TCPS with either basal or cardiac induction medium for 9 days, the spheroids spread into a monolayer and the positive effect on cardiomyogenic marker gene expression disappeared. The possible role of calcium ion and the up-regulation of adhesion molecule P-selectin and chemokine receptor Cxcr4 were demonstrated in ASC spheroids. Applying these spheroids to the chronic myocardial infarction animal model showed better functional recovery versus single cells after 12 weeks. Taken together, this study suggested that the ASC spheroids on chitosan may form as a result of calcium ion signaling, and the transplantation of these spheroids may offer a simple method to enhance the efficiency of stem cell-based therapy in myocardial infarction. PMID:23514754

  4. Electrochemically grown ZnO nanorods for hybrid solar cell applications

    SciTech Connect

    Hames, Yakup; Alpaslan, Zuehal; Koesemen, Arif; San, Sait Eren; Yerli, Yusuf

    2010-03-15

    A hybrid solar cell is designed and proposed as a feasible and reasonable alternative, according to acquired efficiency with the employment of zinc oxide (ZnO) nanorods and ZnO thin films at the same time. Both of these ZnO structures were grown electrochemically and poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester; (P3HT:PCBM) was used as an active polymer blend, which was found to be compatible to prepared indium-tin-oxide (ITO) substrate base. This ITO base was introduced with mentioned ZnO structure in such a way that, the most efficient configuration was optimized to be ITO/ZnO film/ZnO nanorod/P3HT: PCBM/Ag. Efficiency of this optimized device is found to be 2.44%. All ZnO works were carried out electrochemically, that is indeed for the first time and at relatively lower temperatures. (author)

  5. Systematic process development towards high performance transferred thin silicon solar cells based on epitaxially grown absorbers

    NASA Astrophysics Data System (ADS)

    Murcia Salazar, Clara Paola

    ). First principles modeling, however, predicts that efficiencies of 20+% are achievable with less than 20 mum of c-Si. In addition to a high voltage design, this work reports state of the art epitaxial c-Si solar cell performance and a path towards 20+%-efficient transferred epitaxial solar cells. The design and fabrication approach is based on high open circuit voltage first, high short circuit current second. A first design is a thin solar cell grown on a conductive silicon wafer. This structure allows developing processes to increase bulk lifetime and reduce surface recombination. Important processes that can be used for a transferred solar cell such as increased fill factor (FF) are developed at this stage. A second design is based on the use of a separation layer prior to the solar cell growth. We achieve a comparable performance with the second design. A third design includes the transfer of the solar cell to a secondary substrate. Initial processing development is reported for the transferred solar cells. Improvements in solar cell critical parameters have been characterized with a combination of predictive modeling and solar cell diagnostic tools such as quantum efficiency and voltage measurements. Fabrication processes have been developed to improve solar cell performance. The combination of process development, test structures, systematic fabrication, testing and analysis concludes with a path to high voltage, transferred thin c-Si solar cells towards 20+% efficiencies.

  6. Canine and Equine Mesenchymal Stem Cells Grown in Serum Free Media Have Altered Immunophenotype.

    PubMed

    Clark, Kaitlin C; Kol, Amir; Shahbenderian, Salpi; Granick, Jennifer L; Walker, Naomi J; Borjesson, Dori L

    2016-04-01

    Mesenchymal stem cell (MSC) therapy is being increasingly used to treat dogs and horses with naturally-occurring diseases. However these animals also serve as critical large animal models for ongoing translation of cell therapy products to the human market. MSC manufacture for clinical use mandates improvement in cell culture systems to meet demands for higher MSC numbers and removal of xeno-proteins (i.e. fetal bovine serum, FBS). While serum-free media (SFM) is commercially available, its affects on MSC phenotype and immunomodulatory functions are not fully known. The objective of this study was to determine if specific MSC culture conditions, MSC expansion in HYPERFlasks® or MSC expansion in a commercially available SFM, would alter MSC proliferation, phenotype or immunomodulatory properties in vitro. MSCs cultured in HYPERFlasks® were similar in phenotype, proliferative capacity and immunomodulatory functions to MSCs grown in standard flasks however MSC yield was markedly increased. HYPERFlasks® therefore provide a viable option to generate greater cell numbers in a streamlined manner. Canine and equine MSCs expanded in SFM displayed similar proliferation, surface phenotype and inhibitory effect on lymphocyte proliferation in vitro. However, MSCs cultured in the absence of FBS secreted significantly less PGE2, and were significantly less able to inhibit IFNγ secretion by activated T-cells. Immunomodulatory functions altered by expansion in SFM were species dependent. Unlike equine MSCs, in canine adipose-derived MSCs, the inhibition of lymphocyte proliferation was not principally modulated by PGE2. The removal of FBS from both canine and equine MSC culture systems resulted in altered immunomodulatory properties in vitro and warrants further investigation prior to moving towards FBS-free culture conditions. PMID:26638159

  7. GaSb thermophotovoltaic cells grown on GaAs by molecular beam epitaxy using interfacial misfit arrays

    SciTech Connect

    Juang, Bor-Chau Laghumavarapu, Ramesh B.; Foggo, Brandon J.; Lin, Andrew; Simmonds, Paul J.; Liang, Baolai; Huffaker, Diana L.

    2015-03-16

    There exists a long-term need for foreign substrates on which to grow GaSb-based optoelectronic devices. We address this need by using interfacial misfit arrays to grow GaSb-based thermophotovoltaic cells directly on GaAs (001) substrates and demonstrate promising performance. We compare these cells to control devices grown on GaSb substrates to assess device properties and material quality. The room temperature dark current densities show similar characteristics for both cells on GaAs and on GaSb. Under solar simulation the cells on GaAs exhibit an open-circuit voltage of 0.121 V and a short-circuit current density of 15.5 mA/cm{sup 2}. In addition, the cells on GaAs substrates maintain 10% difference in spectral response to those of the control cells over a large range of wavelengths. While the cells on GaSb substrates in general offer better performance than the cells on GaAs substrates, the cost-savings and scalability offered by GaAs substrates could potentially outweigh the reduction in performance. By further optimizing GaSb buffer growth on GaAs substrates, Sb-based compound semiconductors grown on GaAs substrates with similar performance to devices grown directly on GaSb substrates could be realized.

  8. GaSb thermophotovoltaic cells grown on GaAs by molecular beam epitaxy using interfacial misfit arrays

    NASA Astrophysics Data System (ADS)

    Juang, Bor-Chau; Laghumavarapu, Ramesh B.; Foggo, Brandon J.; Simmonds, Paul J.; Lin, Andrew; Liang, Baolai; Huffaker, Diana L.

    2015-03-01

    There exists a long-term need for foreign substrates on which to grow GaSb-based optoelectronic devices. We address this need by using interfacial misfit arrays to grow GaSb-based thermophotovoltaic cells directly on GaAs (001) substrates and demonstrate promising performance. We compare these cells to control devices grown on GaSb substrates to assess device properties and material quality. The room temperature dark current densities show similar characteristics for both cells on GaAs and on GaSb. Under solar simulation the cells on GaAs exhibit an open-circuit voltage of 0.121 V and a short-circuit current density of 15.5 mA/cm2. In addition, the cells on GaAs substrates maintain 10% difference in spectral response to those of the control cells over a large range of wavelengths. While the cells on GaSb substrates in general offer better performance than the cells on GaAs substrates, the cost-savings and scalability offered by GaAs substrates could potentially outweigh the reduction in performance. By further optimizing GaSb buffer growth on GaAs substrates, Sb-based compound semiconductors grown on GaAs substrates with similar performance to devices grown directly on GaSb substrates could be realized.

  9. Tilted bulk heterojunction organic photovoltaic cells grown by oblique angle deposition

    NASA Astrophysics Data System (ADS)

    Li, Ning; Forrest, Stephen R.

    2009-09-01

    We demonstrate small molecule bulk heterojunction organic photovoltaic cells using oblique angle vacuum deposition. Obliquely deposited donor chloroaluminum phthalocyanine (ClAlPc) films on indium tin oxide have surface feature sizes of ˜30 nm, resulting in ClAlPc/C60 donor-acceptor heterojunctions (HJs) with approximately twice the interface area of HJs grown at normal incidence. This results in nearly twice the external quantum efficiency in the ClAlPc absorption band compared with analogous, planar HJs. The efficiency increase is attributed to the increased surface area presented by the donor-acceptor junction to the incident illumination by ClAlPc protrusions lying obliquely to the substrate plane formed during deposition. The power conversion efficiency improves from (2.0±0.1)% to (2.8±0.1)% under 1 sun, AM 1.5G simulated solar illumination. Similarly, the power efficiency of copper phthalocyanine/C60 organic photovoltaic cells is increased from (1.3±0.1)% to (1.7±0.1)%.

  10. Radial junction amorphous silicon solar cells on PECVD-grown silicon nanowires

    NASA Astrophysics Data System (ADS)

    Yu, Linwei; O'Donnell, Benedict; Foldyna, Martin; Cabarrocas, Pere Roca i.

    2012-05-01

    Constructing radial junction hydrogenated amorphous silicon (a-Si:H) solar cells on top of silicon nanowires (SiNWs) represents a promising approach towards high performance and cost-effective thin film photovoltaics. We here develop an all-in situ strategy to grow SiNWs, via a vapour-liquid-solid (VLS) mechanism on top of ZnO-coated glass substrate, in a plasma-enhanced chemical vapour deposition (PECVD) reactor. Controlling the distribution of indium catalyst drops allows us to tailor the as-grown SiNW arrays into suitable size and density, which in turn results in both a sufficient light trapping effect and a suitable arrangement allowing for conformal coverage of SiNWs by subsequent a-Si:H layers. We then demonstrate the fabrication of radial junction solar cells and carry on a parametric study designed to shed light on the absorption and quantum efficiency response, as functions of the intrinsic a-Si:H layer thickness and the density of SiNWs. These results lay a solid foundation for future structural optimization and performance ramp-up of the radial junction thin film a-Si:H photovoltaics.

  11. Berry extracts exert different antiproliferative effects against cervical and colon cancer cells grown in vitro.

    PubMed

    McDougall, Gordon J; Ross, Heather A; Ikeji, Magnus; Stewart, Derek

    2008-05-14

    Polyphenol-rich berry extracts were screened for their antiproliferative effectiveness using human cervical cancer (HeLa) cells grown in microtiter plates. Rowan berry, raspberry, lingonberry, cloudberry, arctic bramble, and strawberry extracts were effective but blueberry, sea buckthorn, and pomegranate extracts were considerably less effective. The most effective extracts (strawberry > arctic bramble > cloudberry > lingonberry) gave EC 50 values in the range of 25-40 microg/(mL of phenols). These extracts were also effective against human colon cancer (CaCo-2) cells, which were generally more sensitive at low concentrations but conversely less sensitive at higher concentrations. The strawberry, cloudberry, arctic bramble, and the raspberry extracts share common polyphenol constituents, especially the ellagitannins, which have been shown to be effective antiproliferative agents. However, the components underlying the effectiveness of the lingonberry extracts are not known. The lingonberry extracts were fractionated into anthocyanin-rich and tannin-rich fractions by chromatography on Sephadex LH-20. The anthocyanin-rich fraction was considerably less effective than the original extract, whereas the antiproliferative activity was retained in the tannin-rich fraction. The polyphenolic composition of the lingonberry extract was assessed by liquid chromatography-mass spectrometry and was similar to previous reports. The tannin-rich fraction was almost entirely composed of procyanidins of linkage type A and B. Therefore, the antiproliferative activity of lingonberry was caused predominantly by procyanidins. PMID:18412361

  12. Eight-cell parthenotes originated from in vitro grown sheep preantral follicles.

    PubMed

    Luz, V B; Araújo, V R; Duarte, A B G; Celestino, J J H; Silva, T F P; Magalhães-Padilha, D M; Chaves, R N; Brito, I R; Almeida, A P; Campello, C C; Feltrin, C; Bertolini, M; Santos, R R; Figueiredo, J R

    2012-11-01

    We investigated the effect of the leukemia inhibitory factor (LIF) alone or in association with follicle-stimulating hormone (FSH) on the in vitro growth and antrum formation of sheep preantral follicles. To evaluate oocyte quality, parthenogenetic activation of the oocytes recovered from in vitro grown preantral follicles was performed. Preantral follicles >110 μm in diameter were isolated and cultured for 18 days in basic medium either alone (control) or supplemented with LIF (10 or 50 ng/mL) in the absence or presence of FSH. Every 6 days the follicular survival, growth, and antrum formation were evaluated. When compared to control (P < .05), antrum formation was increased in follicles cultured in the presence of LIF10 and FSH. At the end of the culture, the oocytes underwent in vitro maturation (IVM); their viability and chromatin configuration were assessed. Although IVM was not affect by the treatments (P > .05), the numerically highest maturation rates (29.63%) were obtained when follicles were cultured in 50 ng/mL LIF (LIF50). Therefore, their oocytes were submitted to parthenogenetic activation; from which 58.3% of the mature oocytes resulted in 8-cell stage parthenotes. In conclusion, although LIF10 + FSH increases antrum formation when compared to a nonsupplemented medium (minimum essential medium), oocytes from sheep preantral follicles are capable of growing and maturing in vitro independent of LIF addition to the medium, which resulted in the formation of 8-cell parthenotes. PMID:22562971

  13. A polarized cell model for Chikungunya virus infection: entry and egress of virus occurs at the apical domain of polarized cells.

    PubMed

    Lim, Pei Jin; Chu, Justin Jang Hann

    2014-02-01

    Chikungunya virus (CHIKV) has resulted in several outbreaks in the past six decades. The clinical symptoms of Chikungunya infection include fever, skin rash, arthralgia, and an increasing incidence of encephalitis. The re-emergence of CHIKV with more severe pathogenesis highlights its potential threat on our human health. In this study, polarized HBMEC, polarized Vero C1008 and non-polarized Vero cells grown on cell culture inserts were infected with CHIKV apically or basolaterally. Plaque assays, viral binding assays and immunofluorescence assays demonstrated apical entry and release of CHIKV in polarized HBMEC and Vero C1008. Drug treatment studies were performed to elucidate both host cell and viral factors involved in the sorting and release of CHIKV at the apical domain of polarized cells. Disruption of host cell myosin II, microtubule and microfilament networks did not disrupt the polarized release of CHIKV. However, treatment with tunicamycin resulted in a bi-directional release of CHIKV, suggesting that N-glycans of CHIKV envelope glycoproteins could serve as apical sorting signals. PMID:24587455

  14. Proteomic analysis of Staphylococcus aureus biofilm cells grown under physiologically relevant fluid shear stress conditions

    PubMed Central

    2014-01-01

    Background The biofilm forming bacterium Staphylococcus aureus is responsible for maladies ranging from severe skin infection to major diseases such as bacteremia, endocarditis and osteomyelitis. A flow displacement system was used to grow S. aureus biofilms in four physiologically relevant fluid shear rates (50, 100, 500 and 1000 s-1) to identify proteins that are associated with biofilm. Results Global protein expressions from the membrane and cytosolic fractions of S. aureus biofilm cells grown under the above shear rate conditions are reported. Sixteen proteins in the membrane-enriched fraction and eight proteins in the cytosolic fraction showed significantly altered expression (p < 0.05) under increasing fluid shear. These 24 proteins were identified using nano-LC-ESI-MS/MS. They were found to be associated with various metabolic functions such as glycolysis / TCA pathways, protein synthesis and stress tolerance. Increased fluid shear stress did not influence the expression of two important surface binding proteins: fibronectin-binding and collagen-binding proteins. Conclusions The reported data suggest that while the general metabolic function of the sessile bacteria is minimal under high fluid shear stress conditions, they seem to retain the binding capacity to initiate new infections. PMID:24855455

  15. Targeting FAK Radiosensitizes 3-Dimensional Grown Human HNSCC Cells Through Reduced Akt1 and MEK1/2 Signaling

    SciTech Connect

    Hehlgans, Stephanie; Department of Radiotherapy and Oncology, University of Frankfurt, Frankfurt am Main; Institute of Radiopharmacy, Helmholtz Center Dresden-Rossendorf, Dresden ; Eke, Iris; Cordes, Nils; Institute of Radiopharmacy, Helmholtz Center Dresden-Rossendorf, Dresden; Department of Radiation Oncology, University Hospital and Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden

    2012-08-01

    Purpose: Focal adhesion kinase (FAK), a main regulator of integrin signaling and cell migration, is frequently overexpressed and hyperphosphorylated in human head-and-neck squamous cell carcinoma (HNSCC). We have previously shown that pharmacologic FAK inhibition leads to radiosensitization of 3-dimensionally grown HNSCC cell lines. To further evaluate the role of FAK in radioresistance and as a potential cancer target, we examined FAK and FAK downstream signaling in HNSCC cell lines grown in more physiologic extracellular matrix-based 3-dimensional cell cultures. Methods and Materials: Seven HNSCC cell lines were grown in 3-dimensional extracellular matrix and the clonogenic radiation survival, expression, and phosphorylation of FAK, paxillin, Akt1, extracellular signal-regulated kinase (ERK)1/2, and MEK1/2 were analyzed after siRNA-mediated knockdown of FAK, Akt1, MEK1, FAK+Akt1, or FAK+MEK1 compared with controls or stable overexpression of FAK. The role of MEK1/2 for clonogenic survival and signaling was investigated using the MEK inhibitor U0126 with or without irradiation. Results: FAK knockdown moderately or significantly enhanced the cellular radiosensitivity of 3-dimensionally grown HNSCC cells. The FAK downstream targets paxillin, Akt1, and ERK1/2 were substantially dephosphorylated under FAK depletion. FAK overexpression, in contrast, increased radiation survival and paxillin, Akt1, and ERK1/2 phosphorylation. The degree of radiosensitization upon Akt1, ERK1/2, or MEK1 depletion or U0126 was superimposable to FAK knockdown. Combination knockdown conditions (ie, Akt1/FAK, MEK1/FAK, or U0126/FAK) failed to provide additional radiosensitization. Conclusions: Our data provide further evidence for FAK as important determinant of radiation survival, which acts in the same signaling axis as Akt1 and ERK1/2. These data strongly support our hypothesis that FAK is a relevant molecular target for HNSCC radiotherapy.

  16. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  17. Possible pathways linking ploidy level to cell elongation and cuticular function in hypocotyls of dark-grown Arabidopsis seedlings

    PubMed Central

    Narukawa, Hideki; Yokoyama, Ryusuke; Nishitani, Kazuhiko

    2016-01-01

    abstract The mechanisms underlying correlations between ploidy level and cell size in eukaryotes remain unclear. Recently, we showed that cell length was higher in tetraploid than in diploid dark-grown Arabidopsis hypocotyls. Cuticular function was aberrant, and expression of genes of cuticle formation was reduced. Here, the links between cell elongation, cuticular function, and ploidy level in the etiolated hypocotyl were examined. Seedlings defective in cuticle formation exhibited shorter hypocotyls. This was due to inhibition of cell elongation rather than cell proliferation, indicating that the reduced cuticular function was a consequence of tetraploidy-induced cell elongation rather than its cause. Inhibition of hypocotyl elongation by impaired cuticles was lower in tetraploid than diploid, indicating that tetraploid hypocotyls were less sensitive to cuticular damage. PMID:26618780

  18. Accumulation of a novel glycolipid and a betaine lipid in cells of Rhodobacter sphaeroides grown under phosphate limitation.

    PubMed

    Benning, C; Huang, Z H; Gage, D A

    1995-02-20

    Cells of the photosynthetic bacterium Rhodobacter sphaeroides grown under phosphate-limiting conditions accumulated nonphosphorous glycolipids and lipids carrying head groups derived from amino acids. Concomitantly, the relative amount of phosphoglycerolipids decreased from 90 to 22 mol% of total polar lipids in the membranes. Two lipids, not detectable in cells grown under standard conditions, were synthesized during phosphate-limited growth. Fast atom bombardment mass spectroscopy, exact mass measurements, 1H NMR spectroscopy, sugar composition analysis, and methylation analysis of the predominant glycolipid led to the identification of the novel compound 1,2-di-O-acyl-3-O-[alpha-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyr anosyl]glycerol. The second lipid was identified as the betaine lipid 1,2-di-O-acyl-[4'-(N,N,N-trimethyl)-homoserine]glycerol by cochromatography employing an authentic standard from Chlamydomonas reinhardtii, fast atom bombardment mass spectroscopy, exact mass measurements, and 1H NMR spectroscopy. Prior to this observation, the occurrence of this lipid was thought to be restricted to lower plants and algae. Apparently, these newly synthesized nonphosphorous lipids, in addition to the sulfo- and the ornithine lipid also found in R. sphaeroides grown under optimal conditions, take over the role of phosphoglycerolipids in phosphate-deprived cells. PMID:7872771

  19. Mountain grown ginseng induces apoptosis in HL-60 cells and its mechanism have little relation with TNF-alpha production.

    PubMed

    Koo, Hyun-Na; Jeong, Hyun-Ja; Choi, In-Young; An, Hyo-Jin; Moon, Phil-Dong; Kim, Seong-Jin; Jee, Seon-Young; Um, Jae-Young; Hong, Seung-Heon; Shin, Soon-Shik; Yang, Deok-Chun; Seo, Yong-Suk; Kim, Hyung-Min

    2007-01-01

    The root of ginseng is one of the most popular natural tonics in Oriental countries. Ginseng grown in the wild, deep in the mountains, is known as Sansam (mountain grown ginseng, MGG). MGG belongs to Araliaceae and Panax. In this study, we investigated the effects of MGG on the cytotoxicity, induction of apoptosis and the putative pathways of its actions in human promyelocytic leukemia cells, HL-60. Using apoptosis analysis, we found that MGG is a potent inducer of apoptosis, but it has less effect on human peripheral blood mononuclear cells. Caspase-3 activation and subsequent apoptotic cell death in MGG-treated cells were partially blocked by the caspase-3 inhibitor, Z-DEVD-FMK. MGG also inhibited the caspase-8 activity. To determine whether MGG-induced apoptosis is involved in tumor necrosis factor-alpha (TNF-alpha) secretion, TNF-alpha secretion was quantified by enzyme-linked immunosorbent assay (ELISA) method. Unexpectedly, MGG significantly decreased the TNF-alpha secretion compared to the control. These results suggest that MGG-induced cytotoxicity have little relation with the secretion of TNF-alpha in HL-60 cells. Furthermore, MGG with rIFN-gamma synergistically increased nitric oxide (NO) production in mouse peritoneal macrophages. Taken together, our data indicate that MGG is a potent inducer of apoptosis on HL-60 cells and these abilities could be used clinically for the treatment of cancer. PMID:17265560

  20. Growth and characterization of Czochralski-grown n and p-type GaAs for space solar cell substrates

    NASA Technical Reports Server (NTRS)

    Chen, R. T.

    1983-01-01

    Progress in LEC (liquid encapsulated Czochralski) crystal growth techniques for producing high-quality, 3-inch-diameter, n- and p-type GaAs crystals suitable for solar cell applications is described. The LEC crystals with low dislocation densities and background impurities, high electrical mobilities, good dopant uniformity, and long diffusion lengths were reproducibly grown through control of the material synthesis, growth and doping conditions. The capability for producing these large-area, high-quality substrates should positively impact the manufacturability of highly efficiency, low cost, radiation-hard GaAs solar cells.

  1. Epitaxial Crystal Silicon Absorber Layers and Solar Cells Grown at 1.8 Microns per Minute: Preprint

    SciTech Connect

    Bobela, D. C.; Teplin, C. W.; Young, D. L.; Branz, H. M.; Stradins, P.

    2011-07-01

    We have grown device-quality epitaxial silicon thin films at growth rates up to 1.8 μm/min, using hot-wire chemical vapor deposition from silane at substrate temperatures below 750 degrees C. At these rates, which are more than 30 times faster than those used by the amorphous and nanocrystalline Si industry, capital costs for large-scale solar cell production would be dramatically reduced, even for cell absorber layers up to 10 ?m thick. We achieved high growth rates by optimizing the three key parameters: silane flow, depletion, and filament geometry, based on our model developed earlier. Hydrogen coverage of the filament surface likely limits silane decomposition and growth rate at high system pressures. No considerable deterioration in PV device performance is observed when grown at high rate, provided that the epitaxial growth is initiated at low rate. A simple mesa device structure (wafer/epi Si/a-Si(i)/a-Si:H(p)/ITO) with a 2.3 um epitaxial silicon absorber layer was grown at 700 nm/min. The finished device had an open-circuit voltage of 0.424 V without hydrogenation treatment.

  2. Biotransformation of Hydroxylaminobenzene and Aminophenol by Pseudomonas putida 2NP8 Cells Grown in the Presence of 3-Nitrophenol

    PubMed Central

    Zhao, Jian-Shen; Singh, Ajay; Huang, Xiao-Dong; Ward, Owen P.

    2000-01-01

    Biotransformation products of hydroxylaminobenzene and aminophenol produced by 3-nitrophenol-grown cells of Pseudomonas putida 2NP8, a strain grown on 2- and 3-nitrophenol, were characterized. Ammonia, 2-aminophenol, 4-aminophenol, 4-benzoquinone, N-acetyl-4-aminophenol, N-acetyl-2-aminophenol, 2-aminophenoxazine-3-one, 4-hydroquinone, and catechol were produced from hydroxylaminobenzene. Ammonia, N-acetyl-2-aminophenol, and 2-aminophenoxazine-3-one were produced from 2-aminophenol. All of these metabolites were also found in the nitrobenzene transformation medium, and this demonstrated that they were metabolites of nitrobenzene transformation via hydroxylaminobenzene. Production of 2-aminophenoxazine-3-one indicated that oxidation of 2-aminophenol via imine occurred. Rapid release of ammonia from 2-aminophenol transformation indicated that hydrolysis of the imine intermediate was the dominant reaction. The low level of 2-aminophenoxazine-3-one indicated that formation of this compound was probably due to a spontaneous reaction accompanying oxidation of 2-aminophenol via imine. 4-Hydroquinone and catechol were reduction products of 2- and 4-benzoquinones. Based on these transformation products, we propose a new ammonia release pathway via oxidation of aminophenol to benzoquinone monoimine and subsequent hydrolysis for transformation of nitroaromatic compounds by 3-nitrophenol-grown cells of P. putida 2NP8. We propose a parallel mechanism for 3-nitrophenol degradation in P. putida 2NP8, in which all of the possible intermediates are postulated. PMID:10831408

  3. 75 FR 79293 - Amendment and Revocation of Class E Airspace; Vero Beach, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... a notice of proposed rulemaking to amend and remove Class E airspace at Vero Beach, FL (75 FR 65581... 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034..., 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0 2. The incorporation...

  4. Significant Changes in Cell and Chloroplast Development in Young Wheat Leaves (Triticum aestivum cv Hereward) Grown in Elevated CO2.

    PubMed Central

    Robertson, E. J.; Leech, R. M.

    1995-01-01

    Cell and chloroplast development were characterized in young Triticum aestivum cv Hereward leaves grown at ambient (350 [mu]L L-1) or at elevated (650 [mu]L L-1) CO2. In elevated CO2, cell and chloroplast expansion was accelerated by 10 and 25%, respectively, in the first leaf of 7-d-old wheat plants without disruption to the leaf developmental pattern. Elevated CO2 did not affect the number of chloroplasts in relation to mesophyll cell size or the linear relationship between chloroplast number or size and mesophyll cell size. No major changes in leaf anatomy or in chloroplast ultrastructure were detected as a result of growth in elevated CO2, but there was a marked reduction in starch accumulation. In leaf sections fluorescently tagged antisera were used to visualize and quantitate the amount of cytochrome f, the [alpha]- and [beta]-subunits of the coupling factor 1 in ATP synthase, D1 protein of the photosystem II reaction center, the 33-kD protein of the extrinsic oxygen-evolving complex, subunit II of photosystem I, and ribulose-1,5-bisphosphate carboxylase/oxygenase. A significant finding was that in 10 to 20% of the mesophyll cells grown in elevated CO2 the 33-kD protein of the extrinsic oxygen-evolving complex of photosystem II and cytochrome f were deficient by 75%, but the other proteins accumulated normally. PMID:12228342

  5. Single Junction InGaP/GaAs Solar Cells Grown on Si Substrates using SiGe Buffer Layers

    NASA Technical Reports Server (NTRS)

    Ringel, S. A.; Carlin, J. A.; Andre, C. L.; Hudait, M. K.; Gonzalez, M.; Wilt, D. M.; Clark, E. B.; Jenkins, P.; Scheiman, D.; Allerman, A.

    2002-01-01

    Single junction InGaP/GaAs solar cells displaying high efficiency and record high open circuit voltage values have been grown by metalorganic chemical vapor deposition on Ge/graded SiGe/Si substrates. Open circuit voltages as high as 980 mV under AM0 conditions have been verified to result from a single GaAs junction, with no evidence of Ge-related sub-cell photoresponse. Current AM0 efficiencies of close to 16% have been measured for a large number of small area cells, whose performance is limited by non-fundamental current losses due to significant surface reflection resulting from greater than 10% front surface metal coverage and wafer handling during the growth sequence for these prototype cells. It is shown that at the material quality currently achieved for GaAs grown on Ge/SiGe/Si substrates, namely a 10 nanosecond minority carrier lifetime that results from complete elimination of anti-phase domains and maintaining a threading dislocation density of approximately 8 x 10(exp 5) per square centimeter, 19-20% AM0 single junction GaAs cells are imminent. Experiments show that the high performance is not degraded for larger area cells, with identical open circuit voltages and higher short circuit current (due to reduced front metal coverage) values being demonstrated, indicating that large area scaling is possible in the near term. Comparison to a simple model indicates that the voltage output of these GaAs on Si cells follows ideal behavior expected for lattice mismatched devices, demonstrating that unaccounted for defects and issues that have plagued other methods to epitaxially integrate III-V cells with Si are resolved using SiGe buffers and proper GaAs nucleation methods. These early results already show the enormous and realistic potential of the virtual SiGe substrate approach for generating high efficiency, lightweight and strong III-V solar cells.

  6. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Vaisman, M.; Tomasulo, S.; Masuda, T.; Lang, J. R.; Faucher, J.; Lee, M. L.

    2015-02-01

    Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.

  7. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy

    SciTech Connect

    Vaisman, M.; Tomasulo, S.; Masuda, T.; Lang, J. R.; Faucher, J.; Lee, M. L.

    2015-02-09

    Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.

  8. Cu(In,Ga)Se 2 thin-film solar cells grown with cracked selenium

    NASA Astrophysics Data System (ADS)

    Kawamura, Masahiro; Fujita, Toshiyuki; Yamada, Akira; Konagai, Makoto

    2009-01-01

    Cu(In 1-xGa x)Se 2 (CIGS) films have been grown by using cracked selenium. In conventional evaporation system, the Se atoms were supplied as large clusters (Se x, x>5). However, the size of clusters can be reduced by the thermal cracking. The film qualities grown with small clusters (Se x, x<4) would be improved, since the smaller size molecules easily react with elemental metals, resulting in the reduction of selenium vacancies and the enhancement of surface migration. The CIGS films were deposited by the three-stage method with cracked selenium, and the films were evaluated by SEM, XRD, EDX, C- V measurement and admittance spectroscopy. It was found from the C- V characteristics that the carrier concentrations of the CIGS films grown with cracked selenium were increased with increasing the cracking temperature. The result clearly showed that the use of cracked selenium was effective for reduction of selenium vacancies. The conversion efficiency of 15.4% was obtained by using cracked selenium at a cracking temperature of 500 °C.

  9. Pemetrexed alters folate phenotype and inflammatory profile in EA.hy 926 cells grown under low-folate conditions

    PubMed Central

    Hammons, Andrea L.; Summers, Carolyn M.; Jochems, Jeanine; Arora, Jasbir S.; Zhang, Suhong; Blair, Ian A.; Whitehead, Alexander S.

    2014-01-01

    Elevated homocysteine is a risk marker for several major human pathologies. Emerging evidence suggests that perturbations of folate/homocysteine metabolism can directly modify production of inflammatory mediators. Pemetrexed acts by inhibiting thymidylate synthetase (TYMS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). EA.hy 926 cells grown under low (“Lo”) and high (“Hi”) folate conditions were treated with pemetrexed. The concentrations of several intracellular folate derivatives were measured using LC-MRM/MS. Lo cells had lower total folate concentrations and a different distribution of the intracellular folate derivatives than Hi cells. Treatment with pemetrexed caused a decrease in individual folate analytes. Microarray analysis showed that several genes were significantly up or down-regulated in pemetrexed treated Lo cells. Several of the significantly up-regulated transcripts were inflammatory. Changes in transcript levels of selected targets, including C3, IL-8, and DHFR, were confirmed by quantitative RT-PCR. C3 and IL-8 transcript levels were increased in pemetrexed-treated Lo cells relative to Lo controls; DHFR transcript levels were decreased. In Lo cells, IL-8 and C3 protein concentrations were increased following pemetrexed treatment. Pemetrexed drug treatment was shown in this study to have effects that lead to an increase in pro-inflammatory mediators in Lo cells. No such changes were observed in Hi cells, suggesting that pemetrexed could not modify the inflammatory profile in the context of cellular folate sufficiency. PMID:22975265

  10. Effects of Female Sex Hormones on Susceptibility to HSV-2 in Vaginal Cells Grown in Air-Liquid Interface.

    PubMed

    Lee, Yung; Dizzell, Sara E; Leung, Vivian; Nazli, Aisha; Zahoor, Muhammad A; Fichorova, Raina N; Kaushic, Charu

    2016-01-01

    The lower female reproductive tract (FRT) is comprised of the cervix and vagina, surfaces that are continuously exposed to a variety of commensal and pathogenic organisms. Sexually transmitted viruses, such as herpes simplex virus type 2 (HSV-2), have to traverse the mucosal epithelial lining of the FRT to establish infection. The majority of current culture systems that model the host-pathogen interactions in the mucosal epithelium have limitations in simulating physiological conditions as they employ a liquid-liquid interface (LLI), in which both apical and basolateral surfaces are submerged in growth medium. We designed the current study to simulate in vivo conditions by growing an immortalized vaginal epithelial cell line (Vk2/E6E7) in culture with an air-liquid interface (ALI) and examined the effects of female sex hormones on their growth, differentiation, and susceptibility to HSV-2 under these conditions, in comparison to LLI cultures. ALI conditions induced Vk2/E6E7 cells to grow into multi-layered cultures compared to the monolayers present in LLI conditions. Vk2 cells in ALI showed higher production of cytokeratin in the presence of estradiol (E2), compared to cells grown in progesterone (P4). Cells grown under ALI conditions were exposed to HSV-2-green fluorescent protein (GFP) and the highest infection and replication was observed in the presence of P4. Altogether, this study suggests that ALI cultures more closely simulate the in vivo conditions of the FRT compared to the conventional LLI cultures. Furthermore, under these conditions P4 was found to confer higher susceptibility to HSV-2 infection in vaginal cells. The vaginal ALI culture system offers a better alternative to study host-pathogen interactions. PMID:27589787

  11. "allometry" Deterministic Approaches in Cell Size, Cell Number and Crude Fiber Content Related to the Physical Quality of Kangkong (Ipomoea reptans) Grown Under Different Plant Density Pressures

    NASA Astrophysics Data System (ADS)

    Selamat, A.; Atiman, S. A.; Puteh, A.; Abdullah, N. A. P.; Mohamed, M. T. M.; Zulkeefli, A. A.; Othman, S.

    Kangkong, especially the upland type (Ipomoea reptans) is popularly consumed as a vegetable dish in the South East Asian countries for its quality related to Vitamins (A and C) and crude fiber contents. Higher fiber contents would prevent from the occurrence of colon cancer and diverticular disease. With young stem edible portion, its cell number and size contribute to the stem crude fiber content. The mathematical approach of allometry of cell size, number, and fiber content of stem could be used in determining the 'best' plant density pressure in producing the quality young stem to be consumed. Basically, allometry is the ratio of relative increment (growth or change) rates of two parameters, or the change rate associated to the log of measured variables relationship. Kangkog grown equal or lower than 55 plants m-2 produced bigger individual plant and good quality (physical) kangkong leafy vegetable, but with lower total yield per unit area as compared to those grown at higher densities.

  12. Degradation Study of MOVPE-Grown and Zinc-Diffused GaSb Cells for Thermophotovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Schlegl, T.; Abbott, P.; van Riesen, S.; Bett, A. W.

    2004-11-01

    GaSb-based cells are promising candidates for use in thermophotovoltaic (TPV) systems. In order to assess long term cell performance, suitable accelerated ageing tests are required. So far there are no studies concerning the degradation behaviour of GaSb cells. GaSb-based cells produced from MOVPE-grown structures and from zinc vapour diffused structures have been examined. Due to the different device structure, these two types differ in their fabrication technology and also in the anti-reflection coatings (ARC). Two different methods for accelerated ageing have been tested on these cells for TPV applications. The first involves forward bias at an elevated current density equivalent to that which is expected to flow in the real operating TPV system. The second test, storage in a humid (100%) atmosphere at 95°C, examines degradation due to oxidation processes. The behaviour in degradation is found to depend on the specific test condition and on the structure of the cell. In general, the diffused cell structure exhibits a higher stability over the course of the degradation tests.

  13. High-efficiency GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy

    PubMed Central

    2011-01-01

    We report the initial results of GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy (MBE) technique. For GaAs single-junction solar cell, with the application of AlInP as the window layer and GaInP as the back surface field layer, the photovoltaic conversion efficiency of 26% at one sun concentration and air mass 1.5 global (AM1.5G) is realized. The efficiency of 16.4% is also reached for GaInP solar cell. Our results demonstrate that the MBE-grown phosphide-contained III-V compound semiconductor solar cell can be quite comparable to the metal-organic-chemical-vapor-deposition-grown high-efficiency solar cell. PMID:22040124

  14. Development of a 2.0 eV AlGaInP Solar Cell Grown by OMVPE

    SciTech Connect

    Perl, Emmett E.; Simon, John; Geisz, John F.; Olavarria, Waldo; Young, Michelle; Duda, Anna; Dippo, Pat; Friedman, Daniel J.; Steiner, Myles A.

    2015-06-14

    AlGaInP solar cells with a bandgap (Eg) of ~2.0 eV are developed for use in next-generation multijunction photovoltaic devices. This material system is of great interest for both space and concentrator photovoltaics due to its high bandgap, which enables the development of high-efficiency five-junction and six-junction devices and is also useful for solar cells operated at elevated temperatures. In this work, we explore the conditions for the Organometallic Vapor Phase Epitaxy (OMVPE) growth of AlGaInP and study their effects on cell performance. A ~2.0 eV AlGaInP solar cell is demonstrated with an open circuit voltage (VOC) of 1.59V, a bandgap-voltage offset (WOC) of 420mV, a fill factor (FF) of 88.0%, and an efficiency of 14.8%. These AlGaInP cells have attained a similar FF, WOC and internal quantum efficiency (IQE) to the best upright GaInP cells grown in our lab to date.

  15. Temperature coefficients and radiation induced DLTS spectra of MOCVD grown n(+)p InP solar cells

    NASA Technical Reports Server (NTRS)

    Walters, Robert J.; Statler, Richard L.; Summers, Geoffrey P.

    1991-01-01

    The effects of temperature and radiation on n(+)p InP solar cells and mesa diodes grown by metallorganic chemical vapor deposition (MOCVD) were studied. It was shown that MOCVD is capable of consistently producing good quality InP solar cells with Eff greater than 19 percent which display excellent radiation resistance due to minority carrier injection and thermal annealing. It was also shown that universal predictions of InP device performance based on measurements of a small group of test samples can be expected to be quite accurate, and that the degradation of an InP device due to any incident particle spectrum should be predictable from a measurement following a single low energy proton irradiation.

  16. Epitaxially Grown Collagen Fibrils Reveal Diversity in Contact Guidance Behavior among Cancer Cells

    PubMed Central

    2015-01-01

    Invasion of cancer cells into the surrounding tissue is an important step during cancer progression and is driven by cell migration. Cell migration can be random, but often it is directed by various cues such as aligned fibers composed of extracellular matrix (ECM), a process called contact guidance. During contact guidance, aligned fibers bias migration along the long axis of the fibers. These aligned fibers of ECM are commonly composed of type I collagen, an abundant structural protein around tumors. In this paper, we epitaxially grew several different patterns of organized type I collagen on mica and compared the morphology and contact guidance behavior of two invasive breast cancer cell lines (MDA-MB-231 and MTLn3 cells). Others have shown that these cells randomly migrate in qualitatively different ways. MDA-MB-231 cells exert large traction forces, tightly adhere to the ECM, and migrate with spindle-shaped morphology and thus adopt a mesenchymal mode of migration. MTLn3 cells exert small traction forces, loosely adhere to the ECM, and migrate with a more rounded morphology and thus adopt an amoeboid mode of migration. As the degree of alignment of type I collagen fibrils increases, cells become more elongated and engage in more directed contact guidance. MDA-MB-231 cells perceive the directional signal of highly aligned type I collagen fibrils with high fidelity, elongating to large extents and migrating directionally. Interestingly, behavior in MTLn3 cells differs. While highly aligned type I collagen fibril patterns facilitate spreading and random migration of MTLn3 cells, they do not support elongation or directed migration. Thus, different contact guidance cues bias cell migration differently and the fidelity of contact guidance is cell type dependent, suggesting that ECM alignment is a permissive cue for contact guidance, but requires a cell to have certain properties to interpret that cue. PMID:25531276

  17. Enzymatic Detachment of Therapeutic Mesenchymal Stromal Cells Grown on Glass Carriers in a Bioreactor

    PubMed Central

    Salzig, Denise; Schmiermund, Alexandra; P. Grace, Pablo; Elseberg, Christiane; Weber, Christian; Czermak, Peter

    2013-01-01

    Cell therapies require the in vitro expansion of adherent cells such as mesenchymal stromal cells (hMSCs) in bioreactor systems or other culture environments, followed by cell harvest. As hMSCs are strictly adherent cells, cell harvest requires cell detachment. The use of hMSCs for cell therapy requires GMP production in accordance with the guidelines for advanced therapeutic medical products. Therefore, several GMP-conform available proteolytic enzymes were investigated for their ability to promote hMSC detachment. An allogeneic hMSC cell line (hMSC-TERT) that is used in clinical trials in the form of alginate cell capsules was chosen as a model. This study investigated the influence of several factors on the outcome of proteolytic hMSC-TERT detachment. Therefore, hMSC-TERT detachment was analyzed in different cultivation systems (static, dynamic) and in combination with further cell processing including encapsulation. Only two of the commercially available enzymes (AccutaseTM, TrypZeanTM) that fulfill all process requirements (commercial availability, cost, GMP conditions during manufacturing and non-animal origin) are found to be generally suitable for detaching hMSC-TERT. Combining cell detachment with encapsulation demonstrated a high impact of the experimental set up on cell damage. It was preferable to reduce the temperature during detachment and limit the detachment time to a maximum of 20 minutes. Cell detachment in static systems was not comparable with detachment in dynamic systems. Detachment yields in dynamic systems were lower and cell damage was higher for the same experimental conditions. Finally, only TrypZeanTM seemed to be suitable for the detachment of hMSC-TERT from dynamic reactor systems. PMID:24478807

  18. P-doped strontium titanate grown using two target pulsed laser deposition for thin film solar cells

    NASA Astrophysics Data System (ADS)

    Man, Hamdi

    Thin-film solar cells made of Mg-doped SrTiO3 p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg-doped SrTiO3 (STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg-doped STO thin-films were grown by using pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were doped successfully in the stoichiometry. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. UV/Vis Reflection spectroscopy showed that Mg-doped STO thin-films do not reflect significantly except in the ultraviolet region of the spectrum where the reflection percentage increased up to 80%. Self-doped STO thin-films, Indium Tin Oxide (ITO) thin films and stainless steel foil (SSF) were studied in order to observe their characteristics before employing them in Mg-doped STO based solar cells. Self-doped STO thin films were grown using PLD and the results showed that they are capable of serving as the n-type semiconductor in solar cell applications with oxygen vacancies in their structure and low reflectivity. Indium Tin Oxide thin-films grown by PLD system showed low 25-50 ?/square sheet resistance and very low reflection features. Finally, commercially available stainless steel foil substrates were excellent substrates for the inexpensive growth of

  19. Antigenic Protein In Microgravity-Grown Human Mixed Mullerian Tumor (LN1) Cells Preserved In RNA Stabilizing Agent

    NASA Technical Reports Server (NTRS)

    Hammond, Dianne K.; Becker, Jeanne; Elliott, T. F.; Holubec, K.; Baker, T. L.; Love, J. E.

    2004-01-01

    Cells treated with RNAlater(TradeMark) have previously been shown to contain antigenic proteins that can be visualized using Western blot analysis. These proteins seem to be stable for several months when stored in RNA stabilizer at 4 C. Antigenic protein can be recovered from cells that have been processed using an Ambion RNAqueous(Registered TradeMark) kit to remove RNA. In this set of experiments, human mixed Mullerian tumor (LNI) cells grown on the International Space Station during Expedition 3 were examined for antigenic stability after removal of RNA. The cells were stored for three months in RNAlater(TradeMark) and RNA was extracted. The RNA filtrate containing the protein was precipitated, washed, and suspended in buffer containing sodium dodecyl sulfate (SDS). Samples containing equal concentrations of protein were loaded onto SDS-polyacrylamide gels. Proteins were separated by electrophoresis and transferred by Western blot to polyvinylidene fluoride (PVDF) membrane. The Western blots were stained with an enhanced chemiluminescent ECL(Registered Trademark) Plus detection kit (Amersham) and scanned using a Storm 840 gel image analyzer (Amersham, Molecular Dynamics). ImageQuant(Registered TradeMark) software was used to quantify the densities of the protein bands. The ground control and flight LN1 cell samples showed a similar staining pattern over time with antibodies to vimentin, glyceraldehyde-3-phosphate dehydrogenase, and epithelial membrane antigens.

  20. Antigenic Protein In Microgravity-Grown Human Mixed Mullerian Tumor (LN1) Cells Preserved In RNA Stabilizing Agent

    NASA Technical Reports Server (NTRS)

    Hammond, Dianne K.; Becker, Jeanne; Holubec, K.; Baker, T. L.; Love, J. E.

    2004-01-01

    Cells treated with RNAlater(TradeMark) have previously been shown to contain antigenic proteins that can be visualized using Western blot analysis. These proteins seem to be stable for several months when stored in RNA stabilizer at 4 C. Antigenic protein can be recovered from cells that have been processed using an Ambion RNAqueous(Registered TradeMark) kit to remove RNA. In this set of experiments, human mixed Mullerian tumor (LN1) cells grown on the International Space Station during Expedition 3 were examined for antigenic stability after removal of RNA. The cells were stored for three months in RNAlater(TradeMark) and RNA was extracted. The RNA filtrate Containing the protein was precipitated, washed, and suspended in buffer containing sodium dodecyl sulfate (SDS). Samples containing equal concentrations of protein were loaded onto SDS-polyacrylamide gels. Proteins were separated by electrophoresis and transferred by Western blot to polyvinylidene fluoride (PVDF) membrane. The Western blots were stained with an enhanced chemiluminescent ECL(Registered TradeMark)Plus detection kit (Amersham) and scanned using a Storm 840 gel image analyzer (Amersham, Molecular Dynamics). ImageQuant(Registered TradeMark)a software was used to quantify the densities of the protein bands. The ground control and flight LN1 cell samples showed a similar staining pattern over time with antibodies to vimentin, glyceraldehyde-3-phosphate dehydrogenase, and epithelial membrane antigens.

  1. Effects of reaggregated granulosa cells and oocytes derived from early antral follicles on the properties of oocytes grown in vitro.

    PubMed

    Oi, Ayano; Tasaki, Hidetaka; Munakata, Yasuhisa; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

    2015-01-01

    In this study, we examined the effects of reconstructed oocyte-granulosa cell complexes (OGCs) on the development of porcine oocytes derived from early antral follicles (EAFs; 0.5-0.7 mm in diameter). When denuded oocytes were cocultured with granulosa cells derived from other EAFs, the oocytes and granulosa cells aggregated to form OGCs after 2 days of culture. After 14 days of culture, we compared cell number, oocyte diameter, and oocyte chromatin configuration in unmanipulated (natural) OGCs, reconstructed OGCs, and OGCs collected from antral follicles (AFs, 3.0-6.0 mm in diameter). The diameters of oocytes from reconstructed OGCs grown in vitro were not different from those of oocytes from natural OGCs, although they were significantly smaller than those of oocytes from antral follicle (AF) OGCs. Oocyte chromatin configuration did not differ among the 3 OGC groups, but the oocyte nuclear maturation rate was lower in the reconstructed OGCs and higher in the AF OGCs. However, when the in vitro culture period for the reconstructed OGCs was extended by 2 days, the nuclear maturation rate of oocytes from reconstructed OGCs was similar to that of oocytes from natural OGCs. In addition, blastocysts were successfully obtained from oocytes from reconstructed OGCs. In conclusion, we established an innovative culture method that allows oocytes and granulosa cells from EAFs to reaggregate as reconstructed OGCs, which yield oocytes with the ability to develop to the blastocyst stage. PMID:25740588

  2. Effects of reaggregated granulosa cells and oocytes derived from early antral follicles on the properties of oocytes grown in vitro

    PubMed Central

    OI, Ayano; TASAKI, Hidetaka; MUNAKATA, Yasuhisa; SHIRASUNA, Koumei; KUWAYAMA, Takehito; IWATA, Hisataka

    2015-01-01

    In this study, we examined the effects of reconstructed oocyte–granulosa cell complexes (OGCs) on the development of porcine oocytes derived from early antral follicles (EAFs; 0.5–0.7 mm in diameter). When denuded oocytes were cocultured with granulosa cells derived from other EAFs, the oocytes and granulosa cells aggregated to form OGCs after 2 days of culture. After 14 days of culture, we compared cell number, oocyte diameter, and oocyte chromatin configuration in unmanipulated (natural) OGCs, reconstructed OGCs, and OGCs collected from antral follicles (AFs, 3.0–6.0 mm in diameter). The diameters of oocytes from reconstructed OGCs grown in vitro were not different from those of oocytes from natural OGCs, although they were significantly smaller than those of oocytes from antral follicle (AF) OGCs. Oocyte chromatin configuration did not differ among the 3 OGC groups, but the oocyte nuclear maturation rate was lower in the reconstructed OGCs and higher in the AF OGCs. However, when the in vitro culture period for the reconstructed OGCs was extended by 2 days, the nuclear maturation rate of oocytes from reconstructed OGCs was similar to that of oocytes from natural OGCs. In addition, blastocysts were successfully obtained from oocytes from reconstructed OGCs. In conclusion, we established an innovative culture method that allows oocytes and granulosa cells from EAFs to reaggregate as reconstructed OGCs, which yield oocytes with the ability to develop to the blastocyst stage. PMID:25740588

  3. Dye-sensitized solar cells with vertically aligned TiO2 nanowire arrays grown on carbon fibers.

    PubMed

    Cai, Xin; Wu, Hongwei; Hou, Shaocong; Peng, Ming; Yu, Xiao; Zou, Dechun

    2014-02-01

    One-dimensional semiconductor TiO2 nanowires (TNWs) have received widespread attention from solar cell and related optoelectronics scientists. The controllable synthesis of ordered TNW arrays on arbitrary substrates would benefit both fundamental research and practical applications. Herein, vertically aligned TNW arrays in situ grown on carbon fiber (CF) substrates through a facile, controllable, and seed-assisted thermal process is presented. Also, hierarchical TiO2 -nanoparticle/TNW arrays were prepared that favor both the dye loading and depressed charge recombination of the CF/TNW photoanode. An impressive conversion efficiency of 2.48 % (under air mass 1.5 global illumination) and an apparent efficiency of 4.18 % (with a diffuse board) due to the 3D light harvesting of the wire solar cell were achieved. Moreover, efficient and inexpensive wire solar cells made from all-CF electrodes and completely flexible CF-based wire solar cells were demonstrated, taking into account actual application requirements. This work may provide an intriguing avenue for the pursuit of lightweight, cost-effective, and high-performance flexible/wearable solar cells. PMID:24488679

  4. Gene expression patterns in granulosa cells and oocytes at various stages of follicle development as well as in in vitro grown oocyte-and-granulosa cell complexes

    PubMed Central

    MUNAKATA, Yasuhisa; KAWAHARA-MIKI, Ryoka; SHIRATSUKI, Shogo; TASAKI, Hidetaka; ITAMI, Nobuhiko; SHIRASUNA, Koumei; KUWAYAMA, Takehito; IWATA, Hisataka

    2016-01-01

    Follicle development is accompanied by proliferation of granulosa cells and increasing oocyte size. To obtain high-quality oocytes in vitro, it is important to understand the processes that occur in oocytes and granulosa cells during follicle development and the differences between in vivo and in vitro follicle development. In the present study, oocytes and granulosa cells were collected from early antral follicles (EAFs, 0.5–0.7 mm in diameter), small antral follicles (SAFs, 1–3 mm in diameter), large antral follicles (LAFs, 3–7 mm in diameter), and in vitro grown oocyte-and-granulosa cell complexes (OGCs), which were cultured for 14 days after collection from EAFs. Gene expression was analyzed comprehensively using the next-generation sequencing technology. We found top upstream regulators during the in vivo follicle development and compared them with those in in vitro developed OGCs. The comparison revealed that HIF1 is among the top regulators during both in vivo and in vitro development of OGCs. In addition, we found that HIF1-mediated upregulation of glycolysis in granulosa cells is important for the growth of OGCs, but the cellular metabolism differs between in vitro and in vivo grown OGCs. Furthermore, on the basis of comparison of upstream regulators between in vivo and in vitro development of OGCs, we believe that low expression levels of FLT1 (VEGFA receptor), SPP1, and PCSK6 can be considered causal factors of the suboptimal development under in vitro culture conditions. PMID:27108636

  5. Positioning effects on quantum dot solar cells grown by molecular beam epitaxy

    SciTech Connect

    Zhou, D.; Sharma, G.; Fimland, B. O.; Vullum, P. E.; Thomassen, S. F.; Holmestad, R.; Reenaas, T. W.

    2010-02-22

    We report current-voltage and spectral response characteristics of high density InAs/GaAs quantum dot (QD) solar cells with different positions where dots are located. The short circuit current density (J{sub sc}), open circuit voltage (V{sub oc}), and external quantum efficiency of these cells under air mass 1.5 are presented and compared with a GaAs reference cell. An extended photoresponse in contrast to the GaAs reference cell was confirmed for all these cells. The effect of inserting QD layers into emitter and base region on device performance is shown. The J{sub sc} is reduced, while the V{sub oc} is maintained. The cell with QDs located toward the base side shows better performance, confirmed by both current-voltage and spectral response measurements.

  6. Effect of Hypergravity on Localization Calcium Ions in Plant Cells Grown in Vivo and in Vitro

    NASA Astrophysics Data System (ADS)

    Nedukha, Olena

    Using plant callus tissues and Arabidopsis thaliana plants as model systems we have been investigated the effect of hypergravity on the localization and relative content of calcium ions in photosynthesizing cells. The tobacco callus cells in log stage of growth and mesophyll cells from developed A. thaliana leaves were used in the experiments. Plant samples were exposed to hypergravity at 6.5 g, 10g and 14 g for 15-60 min. After centrifugation, dye Fluo-4 was loaded in the control leaves and the centrifuged samples by the standard cytochemical method. Observation of calcium fluorescence was carried out with a laser confocal microscope LSM 5 Pascal at the excitation wave 488 nm (by the argon laser), at emission wavelength 516 nm. The data of the calcium ion distribution and quantification in cells were obtained using software "Pascal" (Carl Zeiss). The effect of hypergravity on redistribution of calcium ions in plant cells has been established. This effect is depended from exposure time and from the value of hypergravity. The cells cultivated in vitro is showed fast response to hypergravity influence. Plasmolysis cells and calcium domains formation have been observed in most of callus cells. This influence was like to that, which was wrote in Funaria hygrometrica protonema cells after 8.5 g influence (Sytnik et al., 1984). Leaf cells of A. thaliana were of less responsively to hypergravity than callus cells. Sytnik K, Kordyum E, Nedukha O. et al. 1984. Plant Cell Under Change of Geophysical Factors. Kiev: Naukova Dumka, 1-134 p.

  7. The density of apical cells of dark-grown protonemata of the moss Ceratodon purpureus

    NASA Technical Reports Server (NTRS)

    Schwuchow, J. M.; Kern, V. D.; Wagner, T.; Sack, F. D.

    2000-01-01

    Determinations of plant or algal cell density (cell mass divided by volume) have rarely accounted for the extracellular matrix or shrinkage during isolation. Three techniques were used to indirectly estimate the density of intact apical cells from protonemata of the moss Ceratodon purpureus. First, the volume fraction of each cell component was determined by stereology, and published values for component density were used to extrapolate to the entire cell. Second, protonemal tips were immersed in bovine serum albumin solutions of different densities, and then the equilibrium density was corrected for the mass of the cell wall. Third, apical cell protoplasts were centrifuged in low-osmolarity gradients, and values were corrected for shrinkage during protoplast isolation. Values from centrifugation (1.004 to 1.015 g/cm3) were considerably lower than from other methods (1.046 to 1.085 g/cm3). This work appears to provide the first corrected estimates of the density of any plant cell. It also documents a method for the isolation of protoplasts specifically from apical cells of protonemal filaments.

  8. Method of measuring nitric oxide release by vascular endothelial cells grown in microfluidic channels

    NASA Astrophysics Data System (ADS)

    Hosseinpour, S.; Liu, A. C.; Barakat, A. I.; Choy, J. C.; Gray, B. L.

    2014-03-01

    In this paper, a simple and versatile method is presented which enables detection of nitric oxide (NO) released from vascular endothelial cells (ECs) cultured in microfluidic structures. The culturing system and NO measurement method allow cell shape to be controlled in a non-invasive manner using microfluidic structures while NO release is monitored for cell shape versus function studies. The culturing system consists of arrays of polydimethylsiloxane (PDMS) fluidic channels 120 micrometers in depth and ranging from 100 micrometers to 3 mm in width. The number of channels in each array is varied to yield a constant cell culture surface area (75 mm2) independent of channel width. The channel surfaces are collagen-coated and ECs are cultured to confluence within the channels. A cell scraper is then used to scrape extraneous cells cultured between channels, and NO measurements are made 18 to 24 hours later. A chemiluminescence-based sensor system (NOA 280i, Sievers NO Analyzer) is utilized to measure sample NO. Initial results indicate that NO concentrations can be measured from different microfluidic channel-containing samples using this method. It is shown that there is no significant difference in NO concentration derived from channels of different widths even though the degree of cell elongation varies due to physical constraint by microfluidic channel walls. However, cells treated with TNFα release more NO than untreated cells in fluidic channels, which is comparable to the function of ECs cultured in conventional culturing systems such as culturing dishes.

  9. Thyrotropin dependent and independent thyroid cell lines selected from FRTL-5 derived tumors grown in nude mice

    SciTech Connect

    Ossendorp, F.A.; Bruning, P.F.; Schuuring, E.M.; Van Den Brink, J.A.; van der Heide, D.; De Vijlder, J.J.; De Bruin, T.W. )

    1990-07-01

    FRTL-5 cells were used to set up a thyroid tumor model system in C3H nu/nu mice. FRTL-5 tumors could be grown in nude mice provided serum TSH levels were elevated. Persistent TSH elevation was obtained by administration of Na131I, rendering the mice hypothyroid. After 4 weeks FRTL-5 cells were injected sc resulting in tumor growth within 2 weeks in eight out of eight mice. Although the tumors showed an apparently undifferentiated histology, lacking normal follicular structures, they were functional since the tumors were capable of concentrating (131)iodine, as demonstrated by nuclear imaging. From one of the tumors a new cell line was isolated (FRTL-5/T) that, like the parental FRTL-5 cell line, was TSH dependent for growth. In a control group of six euthyroid nude mice FRTL-5 tumor growth could not be obtained with one exception. After 3 months one animal developed a small tumor that grew rapidly thereafter. This tumor was easily transplantable in other euthyroid nude mice, showed an undifferentiated histology, and was nonfunctional, as it could not concentrate (131)iodine. From this tumor two cell lines were derived: one cultured in the presence of TSH (FRTL-5/TP) and one in the absence of TSH (FRTL-5/TA). The cell lines were analyzed for TSH responsive functions and TSH receptor expression. Responsiveness to TSH in FRTL-5/T and the parental FRTL-5 cell line were similar for most thyroid specific functions tested. However, FRTL-5/T was less sensitive than FRTL-5 for TSH induced (3H)thymidine incorporation. Both cell lines had two classes of TSH binding sites with high and low affinity respectively. FRTL-5/TP and FRTL-5/TA were both able to grow in TSH free medium and were nonresponsive to TSH in vitro, as tested for (3H)thymidine and (3H)uridine incorporation, iodine uptake, thyroglobulin iodination, and thyroglobulin secretion.

  10. In vitro transformation of BHK21 cells grown in the presence of calcium chromate.

    PubMed

    Fradkin, A; Janoff, A; Lane, B P; Kuschner, M

    1975-04-01

    Concentrations of 0.25 and 0.5 mug/ml calcium chromate (CaCrO4-2H2O)dissolved in Dulbecco's medium were found to alter the growth behavior of BHK21 cells in culture. Treated cells grew as shortened fibroblasts and in random orientation. The changes detected during the first two weeks of culture in the presence of the metal became more pronounced as the number of growth passages increased. In addition to the alterations noted above, chromate-treated cells grew into large clusters in Methocel (an alternative technique to the agar suspension system), while untreated cells underwent, at most, only one or two divisions in Methocel. These alterations in growth properties were irreversible and persisted after removal of the treated cells from chromate-containing medium, suggesting that a heritable change had occurred as opposed to a transient, chromate-dependent alteration of cell growth. This experimental observation suggests that chromate salts and perhaps salts of other metals can transform BHK21 cells in vitro or can select for spontaneously transformed cells. PMID:1167811

  11. Production of putative virulence factors by Renibacterium salmoninarum grown in cell culture.

    PubMed

    McIntosh, D; Flaño, E; Grayson, T H; Gilpin, M L; Austin, B; Villena, A J

    1997-10-01

    A cell culture system, employing the fish cell line Epithelioma papillosum cyprini (EPC), was developed to study the synthesis of intracellular antigen and the expression of putative virulence factors by Renibacterium salmoninarum. EPC cultures infected with R. salmoninarum could be maintained for 7 weeks, during which the pathogen multiplied intracellularly. Immunohistochemical examination of infected cultures revealed the production of the p57 antigen, haemolysin and cytolysin. The intracellular nature of the infection was confirmed by transmission electron microscopic examination of EPC monolayers. A comparison of the relative virulence of bacterial cells cultured in EPC cells and on agar plates revealed that the former were markedly more virulent in challenge experiments with juvenile rainbow trout (Oncorhynchus mykiss Walbaum). The EPC cell culture model provided a system for the study of R. salmoninarum under more natural conditions than those achieved with plate culture techniques. PMID:9353936

  12. Identification of morphological differences between avian influenza A viruses grown in chicken and duck cells.

    PubMed

    Al-Mubarak, Firas; Daly, Janet; Christie, Denise; Fountain, Donna; Dunham, Stephen P

    2015-03-01

    Although wild ducks are considered to be the major reservoirs for most influenza A virus subtypes, they are typically resistant to the effects of the infection. In contrast, certain influenza viruses may be highly pathogenic in other avian hosts such as chickens and turkeys, causing severe illness and death. Following in vitro infection of chicken and duck embryo fibroblasts (CEF and DEF) with low pathogenic avian influenza (LPAI) viruses, duck cells die more rapidly and produce fewer infectious virions than chicken cells. In the current study, the morphology of viruses produced from CEF and DEF cells infected with low pathogenic avian H2N3 was examined. Transmission electron microscopy showed that viruses budding from duck cells were elongated, while chicken cells produced mostly spherical virions; similar differences were observed in viral supernatants. Sequencing of the influenza genome of chicken- and duck-derived H2N3 LPAI revealed no differences, implicating host cell determinants as responsible for differences in virus morphology. Both DEF and CEF cells produced filamentous virions of equine H3N8 (where virus morphology is determined by the matrix gene). DEF cells produced filamentous or short filament virions of equine H3N8 and avian H2N3, respectively, even after actin disruption with cytochalasin D. These findings suggest that cellular factors other than actin are responsible for the formation of filamentous virions in DEF cells. The formation of elongated virions in duck cells may account for the reduced number of infectious virions produced and could have implications for virus transmission or maintenance in the reservoir host. PMID:25613009

  13. Heteroepitaxial film silicon solar cell grown on Ni-W foils

    SciTech Connect

    Wee, Sung Hun; Cantoni, Claudia; Fanning, Thomas; Teplin, Charles; Bogorin, Daniela Florentina; Bornstein, Jon; Bowers, Karen; Schroeter,; Hasoon, Falah; Branz, Howard; Paranthaman, Mariappan Parans; Goyal, Amit

    2013-01-01

    Today, silicon-wafer-based technology dominates the photovoltaic (PV) industry because it enables high efficiency, is produced from abundant, non-toxic materials and is proven in the PV marketplace.[1] However, costs associated with the wafer itself limit ultimate cost reductions.[1,2] PV based on absorber layers of crystalline Si with only 2 to 10 m thickness are a promising route to reduce these costs, while maintaining efficiencies above 15%.[3-5] With the goal of fabricating low-cost film crystalline Si (c-Si), recent research has explored wafer peeling,[6,7] crystallization of amorphous silicon films on glass,[4,8-10] and seed and epitaxy approaches.[3,5,11] In this third approach, one initially forms a seed layer that establishes the grain size and crystalline order. The Si layer is then grown heteroepitaxially on the seed layer, so that it replicates the seed crystal structure. In all of these film c-Si approaches, the critical challenge is to grow c-Si with adequate material quality: specifically, the diffusion length (LD) must be at least three times the film thickness.[12] In polycrystalline Si films, grain boundaries (GBs) are recombination-active and significantly reduce LD. This adverse effects of GBs motivates research into growth of large grained c-Si [13,14] (for a low density of GBs) and biaxially-textured c-Si [11] (for low-angle GBs).

  14. Effects of substrate conductivity on cell morphogenesis and proliferation using tailored, atomic layer deposition-grown ZnO thin films

    PubMed Central

    Choi, Won Jin; Jung, Jongjin; Lee, Sujin; Chung, Yoon Jang; Yang, Cheol-Soo; Lee, Young Kuk; Lee, You-Seop; Park, Joung Kyu; Ko, Hyuk Wan; Lee, Jeong-O

    2015-01-01

    We demonstrate that ZnO films grown by atomic layer deposition (ALD) can be employed as a substrate to explore the effects of electrical conductivity on cell adhesion, proliferation, and morphogenesis. ZnO substrates with precisely tunable electrical conductivity were fabricated on glass substrates using ALD deposition. The electrical conductivity of the film increased linearly with increasing duration of the ZnO deposition cycle (thickness), whereas other physical characteristics, such as surface energy and roughness, tended to saturate at a certain value. Differences in conductivity dramatically affected the behavior of SF295 glioblastoma cells grown on ZnO films, with high conductivity (thick) ZnO films causing growth arrest and producing SF295 cell morphologies distinct from those cultured on insulating substrates. Based on simple electrostatic calculations, we propose that cells grown on highly conductive substrates may strongly adhere to the substrate without focal-adhesion complex formation, owing to the enhanced electrostatic interaction between cells and the substrate. Thus, the inactivation of focal adhesions leads to cell proliferation arrest. Taken together, the work presented here confirms that substrates with high conductivity disturb the cell-substrate interaction, producing cascading effects on cellular morphogenesis and disrupting proliferation, and suggests that ALD-grown ZnO offers a single-variable method for uniquely tailoring conductivity. PMID:25897486

  15. Single-junction GaAsP solar cells grown on SiGe graded buffers on Si

    NASA Astrophysics Data System (ADS)

    Faucher, J.; Gerger, A.; Tomasulo, S.; Ebert, C.; Lochtefeld, A.; Barnett, A.; Lee, M. L.

    2013-11-01

    We have investigated the microstructure and device characteristics of GaAs0.82P0.18 solar cells grown on Si0.20Ge0.80/Si graded buffers. Anti-phase domains (APDs) were largely self-annihilated within the In0.39Ga0.61P initiation layer although a low density of APDs was found to propagate to the surface. A combination of techniques was used to show that the GaAs0.82P0.18 cells have a threading dislocation density of 1.2 ± 0.2 × 107 cm-2. Despite these extended defects, the devices exhibited high open-circuit voltages of 1.10-1.12 V. These results indicate that cascading a GaAs0.82P0.18 top cell with a lower-bandgap Si0.20Ge0.80 cell is a promising approach for high-efficiency dual-junction devices on low-cost Si substrates.

  16. Transcriptome profiling in Arabidopsis inflorescence stems grown under hypergravity in terms of cell walls and plant hormones

    NASA Astrophysics Data System (ADS)

    Tamaoki, D.; Karahara, I.; Nishiuchi, T.; De Oliveira, S.; Schreiber, L.; Wakasugi, T.; Yamada, K.; Yamaguchi, K.; Kamisaka, S.

    2009-07-01

    Land plants rely on lignified secondary cell walls in supporting their body weight on the Earth. Although gravity influences the formation of the secondary cell walls, the regulatory mechanism of their formation by gravity is not yet understood. We carried out a comprehensive analysis of gene expression in inflorescence stems of Arabidopsis thaliana L. using microarray (22 K) to identify genes whose expression is modulated under hypergravity condition (300 g). Total RNA was isolated from the basal region of inflorescence stems of plants grown for 24 h at 300 g or 1 g. Microarray analysis showed that hypergravity up-regulated the expression of 403 genes to more than 2-fold. Hypergravity up-regulated the genes responsible for the biosynthesis or modification of cell wall components such as lignin, xyloglucan, pectin and structural proteins. In addition, hypergravity altered the expression of genes related to the biosynthesis of plant hormones such as auxin and ethylene and that of genes encoding hormone-responsive proteins. Our transcriptome profiling indicates that hypergravity influences the formation of secondary cell walls by modulating the pattern of gene expression, and that auxin and/or ethylene play an important role in signaling hypergravity stimulus.

  17. Investigation of InGaP/(In)AlGaAs/GaAs triple-junction top cells for smart stacked multijunction solar cells grown using molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Sugaya, Takeyoshi; Mochizuki, Toru; Makita, Kikuo; Oshima, Ryuji; Matsubara, Koji; Okano, Yoshinobu; Niki, Shigeru

    2015-08-01

    We report high-quality InGaP/(In)AlGaAs/GaAs triple-junction solar cells fabricated using solid-source molecular beam epitaxy (MBE) for the first time. The triple-junction cells can be used as top cells for smart stacked multijunction solar cells. A growth temperature of 480 °C was found to be suitable for an (In)AlGaAs second cell to obtain high-quality tunnel junctions. The properties of AlGaAs solar cells were better than those of InAlGaAs solar cells when a second cell was grown at 480 °C. The high-quality InGaP/AlGaAs/GaAs solar cell had an impressive open-circuit voltage of 3.1 V. This result indicates that high-performance InGaP/AlGaAs/GaAs triple-junction solar cells can be fabricated using solid-source MBE.

  18. Functional sequences modulated by morphological transitions in human lymphoid cells grown invitro.

    PubMed

    Drewinko, B; Trujillo, J M; Tessmer, C F

    1971-01-15

    Immunoglobulin-producing cells undergo a series of morphological transitions; each configuration displays specific functional attributes. The life cycle of immunocytes may be visualized as a series of functional compartments expressed by morphological sequences. PMID:4099131

  19. Biotransformation of d-Limonene to (+) trans-Carveol by Toluene-Grown Rhodococcus opacus PWD4 Cells

    PubMed Central

    Duetz, Wouter A.; Fjällman, Ann H. M.; Ren, Shuyu; Jourdat, Catherine; Witholt, Bernard

    2001-01-01

    The toluene-degrading strain Rhodococcus opacus PWD4 was found to hydroxylate d-limonene exclusively in the 6-position, yielding enantiomerically pure (+) trans-carveol and traces of (+) carvone. This biotransformation was studied using cells cultivated in chemostat culture with toluene as a carbon and energy source. The maximal specific activity of (+) trans-carveol formation was 14.7 U (g of cells [dry weight])−1, and the final yield was 94 to 97%. Toluene was found to be a strong competitive inhibitor of the d-limonene conversion. Glucose-grown cells did not form any trans-carveol from d-limonene. These results suggest that one of the enzymes involved in toluene degradation is responsible for this allylic monohydroxylation. Another toluene degrader (Rhodococcus globerulus PWD8) had a lower specific activity but was found to oxidize most of the formed trans-carveol to (+) carvone, allowing for the biocatalytic production of this flavor compound. PMID:11375201

  20. Transparent conducting ITAZO anode films grown by a composite target RF magnetron sputtering at room temperature for organic solar cells

    NASA Astrophysics Data System (ADS)

    Sun, Nanhai; Fang, Guojia; Zheng, Qiao; Wang, Mingjun; Liu, Nishuang; Liu, Wei; Zhao, Xingzhong

    2009-08-01

    The preparation and characteristics of AZO co-sputtered ITO (ITAZO) electrodes grown on glass and flexible substrates using a specially designed composite target in organic solar cells are described. It was found that both the electrical and optical properties of the ITAZO films were critically dependent on the Ar/O2 flow ratio and sputtering power. In addition, all ITAZO electrodes show the amorphous structure due to the low substrate temperature. Even though the ITAZO electrode was prepared at room temperature, we can obtain the ITAZO electrode with the sheet resistance of 23 Ω/square (on a glass substrate) and 26 Ω/square (on a flexible substrate) and the average optical transmittance of 87.5% (on a glass substrate) and 86.3% (on a flexible substrate) in the region between 450 and 800 nm wavelength. In addition, the Ar ion treatment of the polyethylene terephthalate (PET) substrate could remove surface contamination and increase the adherence of the ITAZO film with the PET substrate. Furthermore, organic solar cells prepared on the ITAZO electrode under optimized conditions show the typical current density-voltage characteristics with the conversion power efficiency of 3.2%. This indicates that the composite target sputtering technique is a promising sputtering process for transparent conducting electrodes for low-cost solar cell applications.

  1. Photovoltaic characteristics of n(+)pp(+) InP solar cells grown by OMVPE

    NASA Technical Reports Server (NTRS)

    Tyagi, S.; Singh, K.; Bhimnathwala, H.; Ghandhi, S. K.; Borrego, J. M.

    1990-01-01

    The photovoltaic characteristics of n(+)/p/p(+) homojunction InP solar cells fabricated by organometallic vapor-phase epitaxy (OMVPE) are described. The cells are characterized by I-V, C-V and quantum efficiency measurements, and simulations are used to obtain various device and material parameters. The I-V characteristics show a high recombination rate in the depletion region; this is shown to be independent of the impurity used. It is shown that cadmium is easier to use as an acceptor for the p base and p(+) buffer and is therefore beneficial. The high quantum efficiency of 98 percent at long wavelengths measured in these cells indicates a very good collection efficiency in the base. The short-wavelength quantum efficiency is poor, indicating a high surface recombination.

  2. High efficiency GaAs-Ge tandem solar cells grown by MOCVD

    NASA Technical Reports Server (NTRS)

    Vernon, S. M.; Tobin, S. P.; Bajgar, C.; Haven, Victor E.; Geoffroy, L. M.; Lillington, D. R.; Hart, R. E., Jr.

    1989-01-01

    High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers.

  3. Optimization towards high density quantum dots for intermediate band solar cells grown by molecular beam epitaxy

    SciTech Connect

    Zhou, D.; Sharma, G.; Fimland, B. O.; Thomassen, S. F.; Reenaas, T. W.

    2010-02-08

    We report high density quantum dots (QDs) formation with optimized growth temperature and V/III ratio. At lower growth temperature, QD density is increased, due to smaller surface migration length of In adatoms. With higher V/III, the QD density is higher but it results in large clusters formation and decreases the QD uniformity. The QD solar cell was fabricated and examined. An extended spectral response in contrast to the GaAs reference cell was presented but the external quantum efficiency at energies higher than GaAs band gap is reduced, resulting from the degradation for the emitter above the strained QD layers.

  4. Low temperature grown ZnO@TiO{sub 2} core shell nanorod arrays for dye sensitized solar cell application

    SciTech Connect

    Goh, Gregory Kia Liang; Le, Hong Quang; Huang, Tang Jiao; Hui, Benjamin Tan Tiong

    2014-06-01

    High aspect ratio ZnO nanorod arrays were synthesized on fluorine-doped tin oxide glasses via a low temperature solution method. By adjusting the growth condition and adding polyethylenimine, ZnO nanorod arrays with tunable length were successfully achieved. The ZnO@TiO{sub 2} core shells structures were realized by a fast growth method of immersion into a (NH{sub 4}){sub 2}·TiF{sub 6} solution. Transmission electron microscopy, X-ray Diffraction and energy dispersive X-ray measurements all confirmed the existence of a titania shell uniformly covering the ZnO nanorod's surface. Results of solar cell testing showed that addition of a TiO{sub 2} shell to the ZnO nanorod significantly increased short circuit current (from 4.2 to 5.2 mA/cm{sup 2}), open circuit voltage (from 0.6 V to 0.8 V) and fill factor (from 42.8% to 73.02%). The overall cell efficiency jumped from 1.1% for bare ZnO nanorod to 3.03% for a ZnO@TiO{sub 2} core shell structured solar cell with a 18–22 nm shell thickness, a nearly threefold increase. - Graphical abstract: The synthesis process of coating TiO{sub 2} shell onto ZnO nanorod core is shown schematically. A thin, uniform, and conformal shell had been grown on the surface of the ZnO core after immersing in the (NH{sub 4}){sub 2}·TiF{sub 6} solution for 5–15 min. - Highlights: • ZnO@TiO{sub 2} core shell nanorod has been grown on FTO substrate using low temperature solution method. • TEM, XRD, EDX results confirmed the existing of titana shell, uniformly covered rod's surface. • TiO{sub 2} shell suppressed recombination, demonstrated significant enhancement in cell's efficiency. • Core shell DSSC's efficiency achieved as high as 3.03%, 3 times higher than that of ZnO nanorods.

  5. Heteroepitaxial Film Silicon Solar Cell Grown on Ni-W Foils

    SciTech Connect

    Wee, S. H.; Cantoni, C.; Fanning, T. R.; Teplin, C. W.; Bogorin, D. F.; Bornstein, J.; Bowers, K.; Schroeter, P.; Hasoon, F.; Branz, H. M.; Paranthaman, M. P.; Goyal, A.

    2012-03-01

    Heteroepitaxial semiconductor films on low-cost, flexible metal foil templates are a potential route to inexpensive, high-efficiency solar cells. Here, we report epitaxial growth of Si films on low-cost, flexible, biaxially-textured Ni-W substrates. A robust buffer architecture comprised of multiple epitaxial oxide layers has been developed to grow high quality, heteroepitaxial Si films without any undesired reaction between the Si film and the metal substrate and with a single biaxial texture. XRD analysis including {omega}-scans, {phi}-scans, and pole figures confirms that the buffers and silicon are all epitaxial, with excellent cube-on-cube epitaxy. A photo-conversion efficiency of 1.1% is demonstrated from a proof-of-concept heteroepitaxial film Si solar cell.

  6. Development of a dose verification system for Vero4DRT using Monte Carlo method.

    PubMed

    Ishihara, Yoshitomo; Sawada, Akira; Nakamura, Mitsuhiro; Miyabe, Yuki; Tanabe, Hiroaki; Kaneko, Shuji; Takayama, Kenji; Mizowaki, Takashi; Kokubo, Masaki; Hiraoka, Masahiro

    2014-01-01

    Vero4DRT is an innovative image-guided radiotherapy system employing a C-band X-ray head with gimbal mechanics. The purposes of this study were to propose specific MC models of the linac head and multileaf collimator (MLC) for the Vero4DRT and to verify their accuracy. For a 6 MV photon beam delivered by the Vero4DRT, a simulation code was implemented using EGSnrc. The linac head model and the MLC model were simulated based on its specification. Next, the percent depth dose (PDD) and beam profiles at depths of 15, 100, and 200 mm were simulated under source-to-surface distance of 900 and 1000 mm. Field size was set to 150 × 150 mm2 at a depth of 100 mm. Each of the simulated dosimetric metrics was then compared with the corresponding measurements by a 0.125 cc ionization chamber. After that, intra- and interleaf leakage, tongue-and-groove, and rounded-leaf profiles were simulated for the static MLC model. Meanwhile, film measurements were performed using EDR2 films under similar conditions to simulation. The measurement for the rounded-leaf profile was performed using the water phantom and the ionization chamber. The leaf physical density and abutting leaf gap were adjusted to obtain good agreement between the simulated intra- and interleaf leakage profiles and measurements. For the MLC model in step-and-shoot cases, a pyramid and a prostate IMRT field were simulated, while film measurements were performed using EDR2. For the linac head, exclusive of MLC, the difference in PDD was < 1.0% after the buildup region. The simulated beam profiles agreed to within 1.3% at each depth. The MLC model has been shown to reproduce dose measurements within 2.5% for static tests. The MLC is made of tungsten alloy with a purity of 95%. The leaf gap of 0.015 cm and the MLC physical density of 18.0 g/ cm3, which provided the best agreement between the simulated and measured leaf leakage, were assigned to our MC model. As a result, the simulated step-and-shoot IMRT dose

  7. Hybrid solar cells based on dc magnetron sputtered films of n-ITO on APMOVPE grown p-InP

    NASA Technical Reports Server (NTRS)

    Coutts, T. J.; Li, X.; Wanlass, M. W.; Emery, K. A.; Gessert, T. A.

    1988-01-01

    Hybrid indium-tin-oxide (ITO)/InP solar cells are discussed. The cells are constructed by dc magnetron sputter deposition of ITO onto high-quality InP films grown by atmospheric pressure metal-organic vapor-phase epitaxy (APMOVPE). A record efficiency of 18.9 percent, measured under standard Solar Energy Research Institute reporting conditions, has been obtained. The p-InP surface is shown to be type converted, principally by the ITO, but with the extent of conversion being modified by the nature of the sputtering gas. The deposition process, in itself, is not responsible for the type conversion. Dark currents have been suppressed by more than three orders of magnitude by the addition of hydrogen to the sputtering gas during deposition of a thin (5 nm) interface layer. Without this layer, and using only the more usual argon/oxygen mixture, the devices had poorer efficiencies and were unstable. A discussion of associated quantum efficiencies and capacitance/voltage measurements is also presented from which it is concluded that further improvements in efficiency will result from better control over the type-conversion process.

  8. Combined effects of tumor necrosis factor alpha and radiation in the treatment of renal cell carcinoma grown as radia spheroids.

    PubMed

    Van Moorselaar, R J; Schwachöfer, J H; Crooijmans, R P; Van Stratum, P; Debruyne, F M; Schalken, J A

    1990-01-01

    We have investigated the antiproliferative effects of Tumor Necrosis Factor Alpha (TNF) and radiation on a recently described rat renal cell tumor line grown as multicellular tumor spheroids (MTS). Treatment commenced when the spheroids had reached a diameter of 250 microns. TNF was diluted in the tissue culture medium in different concentrations, ranging from 250-1000 ng/ml. TNF monotherapy had a dose-dependent inhibiting effect on spheroid growth. Single-dose irradiation with 2, 4 or 6 Gy also retarded spheroids significantly in their growth. In the combination treatment the highest dose of TNF (1000 ng/ml) was added 4 hours prior to radiation. TNF could not induce a potentiation of the radiation injury at 2 Gy. The combination with 4 Gy, however, had additive and the combination with 6 Gy synergistic antiproliferative effects; in these treatment regimens respectively 2 and 5 out of 24 spheroids were controlled, i.e. cured. These experiments suggest that TNF in combination with radiotherapy may be beneficial for the treatment of renal cell carcinoma or cancer in general. PMID:2285257

  9. Moringa oleifera Lam. (Moringaceae) grown in Nigeria: In vitro antisickling activity on deoxygenated erythrocyte cells

    PubMed Central

    Adejumo, Olufunmilayo E.; Kolapo, Adelodun L.; Folarin, Akintomiwa O.

    2012-01-01

    Context: Traditional medicine, which is more available and affordable for the poor uses medicinal plants for the treatment and management of various ailments, including the sickle cell disease (SCD). About 24 million Nigerians are carriers of this sickled cell gene, while approximately 2.4 million are SCD patients. Moringa oleifera Lam. (Moringaceae) possesses high nutritional value and has been used in folklore medicine to treat various ailments related to pain and inflammation. Chemical, pharmacological and pharmacognostical applications of Moringa oleifera have been reported. Objective: This study investigated the antisickling potential of polar and non-polar extracts of the seed, flower and leaf of Moringa oleifera for the first time. Materials and Methods: Using crude methanol extract, aqueous extract, ethyl acetate and butanol, the in vitro antisickling activities of Moringa oleifera fractions, were evaluated using erythrocyte cells deoxygenated with 2% sodium metabisulphite. p-Hydroxybenzoic acid and normal saline were employed as positive and negative controls. Results: Phytochemical screening revealed the presence of saponins, free anthraquinones, and alkaloids. Extracts of the seed and flower demonstrated a higher (P<0.05) antisickling activity in comparison to the leaf extract. The leaf extract, as well as those of the seed and flower, equally demonstrated a (P<0.05) reversal of sickled erythrocytes. Discussions and Conclusions: These findings suggest that Moringa oleifera may play a role in the management of SCD, by incorporation of its fractions into recipes. More extensive biological evaluations and further studies will be necessary for the chemical characterization of the antisickling principles. PMID:22557922

  10. Performance of microbial electrolysis cells with bioanodes grown at different external resistances.

    PubMed

    Rago, Laura; Monpart, Nuria; Cortés, Pilar; Baeza, Juan A; Guisasola, Albert

    2016-01-01

    Bioelectrochemical systems need an anode with a high abundance of exoelectrogenic bacteria for an optimal performance. Among all possible operational parameters for an efficient enrichment, the role of external resistance in microbial fuel cell (MFC) has gained a lot of interest since it indirectly poises an anode potential, a key parameter for biofilm distribution and morphology. Thus, this work aims at investigating and discussing whether bioanodes selected at different external resistances under MFC operation present different responses under both MFC and microbial electrolysis cell (MEC) operation. A better MEC performance (i.e. shorter start-up time, higher current intensity and higher H2 production rate) was obtained with an anode from an MFC developed under low external resistance. Quantitative real-time polymerase chain reaction (qPCR) confirmed that a low external resistance provides an MFC anodic biofilm with the highest content of Geobacter because it allows higher current intensity, which is correlated to exoelectrogenic activity. High external resistances such as 1,000 Ω led to a slower start-up time under MEC operation. PMID:26942536

  11. Genotoxic Effects of Low- and High-LET Radiation on Human Epithelial Cells Grown in 2-D Versus 3-D Culture

    NASA Technical Reports Server (NTRS)

    Patel, Z. S.; Cucinotta, F. A.; Huff, J. L.

    2011-01-01

    Risk estimation for radiation-induced cancer relies heavily on human epidemiology data obtained from terrestrial irradiation incidents from sources such as medical and occupational exposures as well as from the atomic bomb survivors. No such data exists for exposures to the types and doses of high-LET radiation that will be encountered during space travel; therefore, risk assessment for space radiation requires the use of data derived from cell culture and animal models. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. This work compares the genotoxic effects of radiation on normal human epithelial cells grown in standard 2-D monolayer culture compared to 3-D organotypic co-culture conditions. These 3-D organotypic models mimic the morphological features, differentiation markers, and growth characteristics of fully-differentiated normal human tissue and are reproducible using defined components. Cultures were irradiated with 2 Gy low-LET gamma rays or varying doses of high-LET particle radiation and genotoxic damage was measured using a modified cytokinesis block micronucleus assay. Our results revealed a 2-fold increase in residual damage in 2 Gy gamma irradiated cells grown under organotypic culture conditions compared to monolayer culture. Irradiation with high-LET particle radiation gave similar results, while background levels of damage were comparable under both scenarios. These observations may be related to the phenomenon of "multicellular resistance" where cancer cells grown as 3-D spheroids or in vivo exhibit an increased resistance to killing by chemotherapeutic agents compared to the same cells grown in 2-D culture. A variety of factors are likely involved in mediating this process, including increased cell-cell communication, microenvironment influences, and changes in cell cycle kinetics that may promote survival of damaged cells in 3-D culture that would

  12. Dye-sensitized solar cell employing zinc oxide aggregates grown in the presence of lithium

    DOEpatents

    Zhang, Qifeng; Cao, Guozhong

    2013-10-15

    Provided are a novel ZnO dye-sensitized solar cell and method of fabricating the same. In one embodiment, deliberately added lithium ions are used to mediate the growth of ZnO aggregates. The use of lithium provides ZnO aggregates that have advantageous microstructure, morphology, crystallinity, and operational characteristics. Employing lithium during aggregate synthesis results in a polydisperse collection of ZnO aggregates favorable for porosity and light scattering. The resulting nanocrystallites forming the aggregates have improved crystallinity and more favorable facets for dye molecule absorption. The lithium synthesis improves the surface stability of ZnO in acidic dyes. The procedures developed and disclosed herein also help ensure the formation of an aggregate film that has a high homogeneity of thickness, a high packing density, a high specific surface area, and good electrical contact between the film and the fluorine-doped tin oxide electrode and among the aggregate particles.

  13. Enhanced-Depletion-Width GaInNAs Solar Cells Grown by Molecular-Beam Epitaxy

    SciTech Connect

    Ptak, A. J.; Friedman, D. J.

    2005-01-01

    The 3-junction, GaInP2/GaAs/Ge solar cell is a non-optimized structure due to excess light falling on the Ge junction. Because of this, a fourth junction inserted between the GaAs and Ge subcells could use the excess light and provide an increase in device efficiency. Unfortunately, the leading candidate material, GaInNAs, suffers from very low minority-carrier diffusion lengths compared to its parent compound, GaAs. These low diffusion lengths do not allow for the collection of adequate current to keep the overall 4-junction structure current matched. If the currents generated from the GaInNAs subcell are increased, the possibility exists for practical efficiencies of greater than 40% from this structure.

  14. Synthesis of cell constituents by methane-grown Methylococcus capsulatus and Methanomonas methanooxidans

    PubMed Central

    Lawrence, A. J.; Kemp, M. B.; Quayle, J. R.

    1970-01-01

    1. A study was made of the incorporation of carbon from [14C]methanol by cultures of Methylococcus capsulatus and Methanomonas methanooxidans growing on methane. 2. The distribution of radioactivity within the non-volatile constituents of the ethanol-soluble fractions of the cells, after incubation with labelled substrate for periods of up to 3min, was analysed by chromatography and radioautography. 3. Over 80% of the radioactivity fixed by Methylococcus capsulatus at 30°C at the earliest times of sampling appeared in phosphorylated compounds, of which glucose phosphate constituted 60%. 4. Most of the radioactivity fixed by Methanomonas methanooxidans at 30°C at the earliest times of sampling appeared in serine, malate, aspartate and an unknown compound(s) tentatively suggested to be folate derivative(s). At 16°C, [14C]methanol was fixed predominantly into serine and the unknown compound(s). 5. Extracts of Methylococcus capsulatus contain an enzyme system that catalyses the condensation of formaldehyde and ribose 5-phosphate to give a mixture consisting mainly of fructose phosphate and allulose phosphate. No similar activity was detected in extracts of Methanomonas methanooxidans. A convenient method was developed for assay of this enzyme system. 6. The enzyme system catalysing the condensation of formaldehyde with ribose 5-phosphate is particle-bound in both Methylococcus capsulatus and Pseudomonas methanica and is unstable in the absence of Mg2+. 7. Extracts of Methanomonas methanooxidans contain high activities of d-glycerate–NAD oxidoreductase, whereas extracts of Methylococcus capsulatus and Pseudomonas methanica contain negligible activities of this enzyme. 8. These results indicate that during growth of Methylococcus capsulatus on methane, as with Pseudomonas methanica, cell constituents are made by the ribose phosphate cycle of formaldehyde fixation. This contrasts with Methanomonas methanooxidans, whose assimilation pathway resembles in some features

  15. Use of cycloheximide to study independent lipid metabolism of Chlamydia trachomatis cultivated in mouse L cells grown in serum-free medium.

    PubMed Central

    Reed, S I; Anderson, L E; Jenkin, H M

    1981-01-01

    A system for measuring chlamydial lipid synthesis was developed with mouse L cells grown in serum-free modified Waymouth 752/l medium in a shaker culture. Host lipid synthesis was reduced approximately 90% when cells were incubated for 24 h in medium containing cycloheximide (2 micrograms/ml). Lipid metabolism was monitored by measuring the incorporation of [3H]isoleucine into the total lipid of normal and infected cells. The results suggested that lipid synthesis of Chlamydia trachomatis lymphogranuloma venereum (LGV-404L) was not inhibited by cycloheximide treatment when the chlamydiae were grown in L cells, whereas host lipid synthesis was inhibited. Chlamydial lipid metabolism began about 6 to 12 h after infection when the noninfectious reticulate body was found and continually increased until the beginning of the appearance of intracellular infectious elementary bodies at 24 to 30 h. PMID:7216466

  16. Dilute Nitride GaNP Wide Bandgap Solar Cells Grown by Gas-Source Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Sukrittanon, Supanee

    Integration of III-V semiconductors and Si is a very attractive means to achieve low-cost high-efficiency solar cells. A promising configuration is to utilize a dual-junction solar cell, in which Si is employed as the bottom junction and a wide-bandgap III-V semiconductor as the top junction. The use of a III-V semiconductor as a top junction offers the potential to achieve higher efficiencies than today's best Si solar cell. Dilute nitride GaNP is a promising candidate for the top cell in dual-junction solar cells because it possesses several extremely important attributes: a direct-bandgap that is also tunable as well as easily-attained lattice-match with Si. As a first step towards integration of GaNP solar cells onto Si, the goal of this dissertation is to optimize and demonstrate GaNP solar cells grown by gas-source molecular beam epitaxy (GSMBE) on GaP (001) substrate. The dissertation is divided into three major parts. In the first part, we demonstrate ˜ 2.05 eV ([N]˜ 1.8%) dilute nitride GaNP thin film solar cells, in which the GaNP is closely lattice-matched to Si, on GaP substrates. From transmission electron microscopy (TEM), the device exhibits defects only at the GaNP/GaP interface, and no threading dislocations in an active layer are observed. Our best GaNP solar cell achieved an efficiency of 7.9% with anti-reflection (AR) coating and no window layer. This GaNP solar cell's efficiency is higher than the most efficient GaP solar cell to date and higher than 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 using GaNP are demonstrated. In the second part, we demonstrate the successful fabrication of GaP/GaNP core/shell microwires utilizing a novel technique: top-down reactive-ion etching (RIE) to create the cores and MBE to create the shells. Systematic studies have been

  17. Superparamagnetic iron oxide nanoparticles exert different cytotoxic effects on cells grown in monolayer cell culture versus as multicellular spheroids

    NASA Astrophysics Data System (ADS)

    Theumer, Anja; Gräfe, Christine; Bähring, Franziska; Bergemann, Christian; Hochhaus, Andreas; Clement, Joachim H.

    2015-04-01

    The aim of this study was to investigate the interaction of superparamagnetic iron oxide nanoparticles (SPION) with human blood-brain barrier-forming endothelial cells (HBMEC) in two-dimensional cell monolayers as well as in three-dimensional multicellular spheroids. The precise nanoparticle localisation and the influence of the NP on the cellular viability and the intracellular Akt signalling were studied in detail. Long-term effects of different polymer-coated nanoparticles (neutral fluidMAG-D, anionic fluidMAG-CMX and cationic fluidMAG-PEI) and the corresponding free polymers on cellular viability of HBMEC were investigated by real time cell analysis studies. Nanoparticles exert distinct effects on HBMEC depending on the nanoparticles' surface charge and concentration, duration of incubation and cellular context. The most severe effects were caused by PEI-coated nanoparticles. Concentrations above 25 μg/ml led to increased amounts of dead cells in monolayer culture as well as in multicellular spheroids. On the level of intracellular signalling, context-dependent differences were observed. Monolayer cultures responded on nanoparticle incubation with an increase in Akt phosphorylation whereas spheroids on the whole show a decreased Akt activity. This might be due to the differential penetration and distribution of PEI-coated nanoparticles.

  18. Oxygen Partial Pressure Is a Rate-Limiting Parameter for Cell Proliferation in 3D Spheroids Grown in Physioxic Culture Condition

    PubMed Central

    Gomes, Aurélie; Guillaume, Ludivine; Grimes, David Robert; Fehrenbach, Jérôme; Lobjois, Valérie; Ducommun, Bernard

    2016-01-01

    The in situ oxygen partial pressure in normal and tumor tissues is in the range of a few percent. Therefore, when studying cell growth in 3D culture systems, it is essential to consider how the physiological oxygen concentration, rather than the one in the ambient air, influences the proliferation parameters. Here, we investigated the effect of reducing oxygen partial pressure from 21% to 5% on cell proliferation rate and regionalization in a 3D tumor spheroid model. We found that 5% oxygen concentration strongly inhibited spheroid growth, changed the proliferation gradient and reduced the 50% In Depth Proliferation index (IDP50), compared with culture at 21% oxygen. We then modeled the oxygen partial pressure profiles using the experimental data generated by culturing spheroids in physioxic and normoxic conditions. Although hypoxia occurred at similar depth in spheroids grown in the two conditions, oxygen partial pressure was a major rate-limiting factor with a critical effect on cell proliferation rate and regionalization only in spheroids grown in physioxic condition and not in spheroids grown at atmospheric normoxia. Our findings strengthen the need to consider conducting experiment in physioxic conditions (i.e., tissue normoxia) for proper understanding of cancer cell biology and the evaluation of anticancer drugs in 3D culture systems. PMID:27575790

  19. Oxygen Partial Pressure Is a Rate-Limiting Parameter for Cell Proliferation in 3D Spheroids Grown in Physioxic Culture Condition.

    PubMed

    Gomes, Aurélie; Guillaume, Ludivine; Grimes, David Robert; Fehrenbach, Jérôme; Lobjois, Valérie; Ducommun, Bernard

    2016-01-01

    The in situ oxygen partial pressure in normal and tumor tissues is in the range of a few percent. Therefore, when studying cell growth in 3D culture systems, it is essential to consider how the physiological oxygen concentration, rather than the one in the ambient air, influences the proliferation parameters. Here, we investigated the effect of reducing oxygen partial pressure from 21% to 5% on cell proliferation rate and regionalization in a 3D tumor spheroid model. We found that 5% oxygen concentration strongly inhibited spheroid growth, changed the proliferation gradient and reduced the 50% In Depth Proliferation index (IDP50), compared with culture at 21% oxygen. We then modeled the oxygen partial pressure profiles using the experimental data generated by culturing spheroids in physioxic and normoxic conditions. Although hypoxia occurred at similar depth in spheroids grown in the two conditions, oxygen partial pressure was a major rate-limiting factor with a critical effect on cell proliferation rate and regionalization only in spheroids grown in physioxic condition and not in spheroids grown at atmospheric normoxia. Our findings strengthen the need to consider conducting experiment in physioxic conditions (i.e., tissue normoxia) for proper understanding of cancer cell biology and the evaluation of anticancer drugs in 3D culture systems. PMID:27575790

  20. Variable temperature carrier dynamics in bulk (In)GaAsNSb materials grown by MOVPE for multi-junction solar cells

    NASA Astrophysics Data System (ADS)

    Sin, Yongkun; Lingley, Zachary; LaLumondiere, Stephen; Wells, Nathan; Lotshaw, William; Moss, Steven C.; Kim, Tae Wan; Mawst, Luke J.; Kuech, Thomas F.

    2014-03-01

    III-V multi-junction solar cells are typically based on a triple-junction design that consists of an InGaP top junction, a GaAs middle junction, and a bottom junction that employs a 1 - 1.25 eV material grown on GaAs substrates. The most promising 1 - 1.25 eV material that is currently under extensive investigation is bulk dilute nitride such as (In)GaAsNSb lattice matched to GaAs substrates. The approach utilizing dilute nitrides has a great potential to achieve high performance triple-junction solar cells as recently demonstrated by Wiemer, et al., who achieved a record efficiency of 43.5% from multi-junction solar cells including MBE-grown dilute nitride materials [1]. Although MOVPE is a preferred technique over MBE for III-V multi-junction solar cell manufacturing, MOVPEgrown dilute nitride research is at its infancy compared to MBE-grown dilute nitride. In particular, carrier dynamics studies are indispensible in the optimization of MOVPE materials growth parameters to obtain improved solar cell performance. For the present study, we employed time-resolved photoluminescence (TR-PL) techniques to study carrier dynamics in MOVPE-grown bulk dilute nitride InGaAsN materials (Eg = 1 - 1.25 eV at RT) lattice matched to GaAs substrates. In contrast to our earlier samples that showed high background C doping densities, our current samples grown using different metalorganic precursors at higher growth temperatures showed a significantly reduced background doping density of ~ 1017 /cm3. We studied carrier dynamics in (In)GaAsNSb double heterostructures (DH) with different N compositions at room temperature. Post-growth annealing yielded significant improvements in carrier lifetimes of (In)GaAsNSb double heterostructure (DH) samples. Carrier dynamics at various temperatures between 10 K and RT were also studied from (In)GaAsNSb DH samples including those samples grown on different orientation substrates.

  1. Expression Profile of Drug and Nutrient Absorption Related Genes in Madin-Darby Canine Kidney (MDCK) Cells Grown under Differentiation Conditions

    PubMed Central

    Quan, Yong; Jin, Yisheng; Faria, Teresa N.; Tilford, Charles A.; He, Aiqing; Wall, Doris A.; Smith, Ronald L.; Vig, Balvinder S.

    2012-01-01

    The expression levels of genes involved in drug and nutrient absorption were evaluated in the Madin-Darby Canine Kidney (MDCK) in vitro drug absorption model. MDCK cells were grown on plastic surfaces (for 3 days) or on Transwell® membranes (for 3, 5, 7, and 9 days). The expression profile of genes including ABC transporters, SLC transporters, and cytochrome P450 (CYP) enzymes was determined using the Affymetrix® Canine GeneChip®. Expression of genes whose probe sets passed a stringent confirmation process was examined. Expression of a few transporter (MDR1, PEPT1 and PEPT2) genes in MDCK cells was confirmed by RT-PCR. The overall gene expression profile was strongly influenced by the type of support the cells were grown on. After 3 days of growth, expression of 28% of the genes was statistically different (1.5-fold cutoff, p < 0.05) between the cells grown on plastic and Transwell® membranes. When cells were differentiated on Transwell® membranes, large changes in gene expression profile were observed during the early stages, which then stabilized after 5–7 days. Only a small number of genes encoding drug absorption related SLC, ABC, and CYP were detected in MDCK cells, and most of them exhibited low hybridization signals. Results from this study provide valuable reference information on endogenous gene expression in MDCK cells that could assist in design of drug-transporter and/or drug-enzyme interaction studies, and help interpret the contributions of various transporters and metabolic enzymes in studies with MDCK cells. PMID:24300234

  2. Porous, single crystalline titanium nitride nanoplates grown on carbon fibers: excellent counter electrodes for low-cost, high performance, fiber-shaped dye-sensitized solar cells.

    PubMed

    Chen, Liang; Dai, Hui; Zhou, Yong; Hu, Yingjie; Yu, Tao; Liu, Jianguo; Zou, Zhigang

    2014-11-28

    An excellent, platinum free fiber counter electrode (CE) was successfully fabricated, consisting of porous, single crystalline titanium nitride (TiN) nanoplates grown on carbon fibers (CF). The fiber-shaped dye-sensitized solar cells (FDSSCs) based on the TiN-CF CE show a high conversion efficiency of 7.20%, comparable or even superior to that of the Pt wire (6.23%). PMID:25068835

  3. Direct sequencing of the HA gene of influenza (H3N2) virus in original clinical samples reveals sequence identity with mammalian cell-grown virus.

    PubMed Central

    Katz, J M; Wang, M; Webster, R G

    1990-01-01

    When influenza (H3N2) viruses from infected individuals are grown in embryonated chicken eggs, viruses are isolated which differ antigenically and structurally from viruses grown in mammalian Madin-Darby canine kidney (MDCK) cell culture [G.C. Schild, J.S. Oxford, J.C. de Jong, and R.G. Webster, Nature (London) 303:706-709, 1983]. To determine which of these viruses is most representative of virus replicating in the infected individual, a region of the HA gene of virus present in original clinical samples was amplified by using the polymerase chain reaction and sequenced directly. Comparison of 170 amino acid residues of HA1 flanking and containing the receptor-binding site and antigenic sites indicated that over this region, the HA of virus replicating in the infected individual was identical to that of virus after growth in MDCK cells and was distinct from the HA of viruses grown in eggs. Therefore, cultivation of human influenza H3N2 virus in mammalian MDCK cells results in a virus similar to the predominant population of virus found in the infected individual. PMID:2319652

  4. Changes of ribulose bisphosphate carboxylase/oxygenase content, ribulose bisphosphate concentration, and photosynthetic activity during adaptation of high-CO/sub 2/ grown cells to low-CO/sub 2/ conditions in Chlorella pyrenoidosa

    SciTech Connect

    Yokota, A.; Canvin, D.T.

    1986-02-01

    Changes of some photosynthetic properties of high-CO/sub 2/ grown cells of Chlorella pyrenoidosa during adaptation to low-CO/sub 2/ conditions have been investigated. The K/sub m/ value of photosynthesis of the high-CO/sub 2/ grown cells for dissolved inorganic carbon was 3.3 millimolar and decreased to 25 to 30 micromolar within 4 hours after transferring to air. In the presence of saturating CO/sub 2/ concentrations the photosynthetic activity of the high-CO/sub 2/ grown cells was 1.5 times as high as that of the low-CO/sub 2/ grown cells. There was a significant rise of the photosynthetic activity during adaptation of the high-CO/sub 2/ grown cells to air, followed by a steady decrease. The activity of ribulose 1,5-bisphosphate carboxylase/oxygenase in both the high and low-CO/sub 2/ grown cells was close to the photosynthetic activity of the cells. The concentration of ribulose 1,5-bisphosphate (RuBP) was higher in the low-CO/sub 2/ adapting and low-CO/sub 2/ grown celsl than in the high-CO/sub 2/ grown cells regardless of the photosynthetic rate. This seems to be due to an increased RuBP regeneration activity during adaptation followed by maintenance of the new higher concentration. The RuBP level always exceeded the concentration of ribulose 1,5-bisphosphate carboxylase/oxygenase RuBP binding sites in both the high- and low-CO/sub 2/ grown cells at any dissolved inorganic carbon concentration.

  5. SU-E-J-129: A Strategy to Consolidate the Image Database of a VERO Unit Into a Radiotherapy Management System

    SciTech Connect

    Yan, Y; Medin, P; Yordy, J; Zhao, B; Jiang, S

    2014-06-01

    Purpose: To present a strategy to integrate the imaging database of a VERO unit with a treatment management system (TMS) to improve clinical workflow and consolidate image data to facilitate clinical quality control and documentation. Methods: A VERO unit is equipped with both kV and MV imaging capabilities for IGRT treatments. It has its own imaging database behind a firewall. It has been a challenge to transfer images on this unit to a TMS in a radiation therapy clinic so that registered images can be reviewed remotely with an approval or rejection record. In this study, a software system, iPump-VERO, was developed to connect VERO and a TMS in our clinic. The patient database folder on the VERO unit was mapped to a read-only folder on a file server outside VERO firewall. The application runs on a regular computer with the read access to the patient database folder. It finds the latest registered images and fuses them in one of six predefined patterns before sends them via DICOM connection to the TMS. The residual image registration errors will be overlaid on the fused image to facilitate image review. Results: The fused images of either registered kV planar images or CBCT images are fully DICOM compatible. A sentinel module is built to sense new registered images with negligible computing resources from the VERO ExacTrac imaging computer. It takes a few seconds to fuse registered images and send them to the TMS. The whole process is automated without any human intervention. Conclusion: Transferring images in DICOM connection is the easiest way to consolidate images of various sources in your TMS. Technically the attending does not have to go to the VERO treatment console to review image registration prior delivery. It is a useful tool for a busy clinic with a VERO unit.

  6. A multiple p-n junction structure obtained from as-grown Czochralski silicon crystals by heat treatment - Application to solar cells

    NASA Technical Reports Server (NTRS)

    Chi, J. Y.; Gatos, H. C.; Mao, B. Y.

    1980-01-01

    Multiple p-n junctions have been prepared in as-grown Czochralski p-type silicon through overcompensation near the oxygen periodic concentration maxima by oxygen thermal donors generated during heat treatment at 450 C. Application of the multiple p-n-junction configuration to photovoltaic energy conversion has been investigated. A new solar-cell structure based on multiple p-n-junctions was developed. Theoretical analysis showed that a significant increase in collection efficiency over the conventional solar cells can be achieved.

  7. Magnesium doping of efficient GaAs and Ga(0.75)In(0.25)As solar cells grown by metalorganic chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Lewis, C. R.; Ford, C. W.; Werthen, J. G.

    1984-01-01

    Magnesium has been substituted for zinc in GaAs and Ga(0.75)In(0.25)As solar cells grown by metalorganic chemical vapor deposition (MOCVD). Bis(cyclopentadienyl)magnesium (Cp2Mg) is used as the MOCVD transport agent for Mg. Full retention of excellent material quality and efficient cell performance results. The substitution of Mg for Zn would enhance the abruptness and reproducibility of doping profiles, and facilitate high temperature processing and operation, due to the much lower diffusion coefficient of Mg, relative to Zn, in these materials.

  8. ZnO nanowires array grown on Ga-doped ZnO single crystal for dye-sensitized solar cells.

    PubMed

    Hu, Qichang; Li, Yafeng; Huang, Feng; Zhang, Zhaojun; Ding, Kai; Wei, Mingdeng; Lin, Zhang

    2015-01-01

    High quality ZnO nanowires arrays were homoepitaxial grown on Ga-doped ZnO single crystal (GZOSC), which have the advantages of high conductivity, high carrier mobility and high thermal stability. When it was employed as a photoanode in the DSSCs, the cell exhibited a 1.44% power-conversion efficiency under the illumination of one sun (AM 1.5G). The performance is superior to our ZnO nanowires/FTO based DSSCs under the same condition. This enhanced performance is mainly attributed to the perfect interface between the ZnO nanowires and the GZOSC substrate that contributes to lower carrier scattering and recombination rates compared with that grown on traditional FTO substrate. PMID:26099568

  9. ZnO nanowires array grown on Ga-doped ZnO single crystal for dye-sensitized solar cells

    PubMed Central

    Hu, Qichang; Li, Yafeng; Huang, Feng; Zhang, Zhaojun; Ding, Kai; Wei, Mingdeng; Lin, Zhang

    2015-01-01

    High quality ZnO nanowires arrays were homoepitaxial grown on Ga-doped ZnO single crystal (GZOSC), which have the advantages of high conductivity, high carrier mobility and high thermal stability. When it was employed as a photoanode in the DSSCs, the cell exhibited a 1.44% power-conversion efficiency under the illumination of one sun (AM 1.5G). The performance is superior to our ZnO nanowires/FTO based DSSCs under the same condition. This enhanced performance is mainly attributed to the perfect interface between the ZnO nanowires and the GZOSC substrate that contributes to lower carrier scattering and recombination rates compared with that grown on traditional FTO substrate. PMID:26099568

  10. GaAs Solar Cells Grown by Hydride Vapor-Phase Epitaxy and the Development of GaInP Cladding Layers

    SciTech Connect

    Simon, John; Schulte, Kevin L.; Young, David L.; Haegel, Nancy M.; Ptak, Aaron J.

    2016-01-01

    The high cost of high-efficiency III-V photovoltaic devices currently limits them to niche markets. Hydride vapor-phase epitaxy (HVPE) growth of III-V materials recently reemerged as a low-cost, high-throughput alternative to conventional metal- organic vapor-phase epitaxy (MOVPE) growth of high-efficiency solar cells. Previously, we demonstrated unpassivated HVPEgrown GaAs p-n junctions with good quantum efficiency and high open-circuit voltage (Voc). In this work, we demonstrate the growth of GaInPby HVPE for use as a high-quality surface passivation layer to GaAs solar cells. Solar cells grown with GaInP window layers show significantly improved quantum efficiency compared with unpassivated cells, increasing the short-circuit current (JSC) of these low-cost devices. These results show the potential of low-cost HVPE for the growth of high-quality III-V devices.

  11. Effects of buffer layer and back-surface field on MBE-grown InGaAsP/InGaAs solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Yuanyuan; Ji, Lian; Dai, Pai; Tan, Ming; Lu, Shulong; Yang, Hui

    2016-02-01

    Solid-state molecular beam epitaxy (MBE)-grown InGaAsP/InGaAs dual-junction solar cells on InP substrates are reported. An efficiency of 10.6% under 1-sun AM1.5 global light intensity is realized for the dual-junction solar cell, while the efficiencies of 16.4 and 12.3% are reached for the top InGaAsP and bottom InGaAs cells, respectively. The effects of the buffer layer and back-surface field on the performance of solar cells are discussed. High device performance is achieved in the case of a low concentration of oxygen and weak recombination when InGaAs buffers and InP back-surface field layers are used, respectively.

  12. Power recovery of radiation damaged MOCVD grown indium phosphide on silicon solar cells through argon-ion laser annealing. Master`s thesis

    SciTech Connect

    Boyer, L.L.

    1996-06-01

    This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide on silicon MOCVD grown solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a large forward-biased current. The InP/Si cells were irradiated with 1 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate four cells with an irradiance of 2.5 W/sq cm, producing a current density 3 to 5 times larger than AMO conditions. Cells were annealed at 19 deg C with the laser and at 25 deg C under AMO conditions. Annealing under laser illumination of n/p-type cells resulted in recovery of 48%. P/n type cells lost 4 to 12% of the assumed degradaton. Annealing under AMO conditions resulted in power recovery of 70% in n/p type cells. P/n-type cells recovered approximately 16% of lost power. Results indicate that significant power recovery results from the annealing of defects within n/p type InP/Si solar cells.

  13. Opsonization of Toxoplasma gondii tachyzoites with nonspecific immunoglobulins promotes their phagocytosis by macrophages and inhibits their proliferation in nonphagocytic cells in tissue culture.

    PubMed

    Vercammen, M; Scorza, T; El Bouhdidi, A; Van Beeck, K; Carlier, Y; Dubremetz, J F; Verschueren, H

    1999-11-01

    We have recently shown that Toxoplasma gondii tachyzoites grown in in vitro culture can bind unspecific immunoglobulin (Ig) through their Fc moiety. We show now that Fc receptors are also present on T. gondii within the host animal, and that intraperitoneal parasites in immunocompetent mice are saturated with unspecific Ig. We have also investigated the effect of the parasite's Fc receptor on the interaction of tachyzoites with mammalian cells, using the Vero cell line as a model for nonphagocytic host cells and murine peritoneal macrophages in primary culture as a model for phagocytic cells. Coating of tachyzoites with parasite-unrelated Ig did not enhance their invasive capacity in either target cell type, but slightly decreased the parasite proliferation. Moreover, phagocytosis by macrophages was increased by approximately 50% when parasites were coated with unspecific Ig. These results indicate that the Fc receptor on T. gondii affects the balance between invasion and phagocytosis in a way that is detrimental to the parasites. PMID:10583856

  14. Synergistic effect of dual interfacial modifications with room-temperature-grown epitaxial ZnO and adsorbed indoline dye for ZnO nanorod array/P3HT hybrid solar cell.

    PubMed

    Chen, Dian-Wei; Wang, Ting-Chung; Liao, Wen-Pin; Wu, Jih-Jen

    2013-09-11

    ZnO nanorod (NR)/poly(3-hexylthiophene) (P3HT) hybrid solar cells with interfacial modifications are investigated in this work. The ZnO NR arrays are modified with room-temperature (RT)-grown epitaxial ZnO shells or/and D149 dye molecules prior to the P3HT infiltration. A synergistic effect of the dual modifications on the efficiency of the ZnO NR/P3HT solar cell is observed. The open-circuit voltage and fill factor are considerable improved through the RT-grown ZnO and D149 modifications in sequence on the ZnO NR array, which brings about a 2-fold enhancement of the efficiency of the ZnO NR/P3HT solar cell. We suggested that the more suitable surface of RT-grown ZnO for D149 adsorption, the chemical compatibility of D149 and P3HT, and the elevated conduction band edge of the RT-grown ZnO/D149-modified ZnO NR array construct the superior interfacial morphology and energetics in the RT-grown ZnO/D149-modified ZnO NR/P3HT hybrid solar cell, resulting in the synergistic effect on the cell efficiency. An efficiency of 1.16% is obtained in the RT-grown ZnO/D149-modified ZnO NR/P3HT solar cell. PMID:23937447

  15. Human umbilical cord Wharton's jelly stem cells undergo enhanced chondrogenic differentiation when grown on nanofibrous scaffolds and in a sequential two-stage culture medium environment.

    PubMed

    Fong, Chui-Yee; Subramanian, Arjunan; Gauthaman, Kalamegam; Venugopal, Jayarama; Biswas, Arijit; Ramakrishna, Seeram; Bongso, Ariff

    2012-03-01

    The current treatments used for osteoarthritis from cartilage damage have their disadvantages of donor site morbidity, complicated surgical interventions and risks of infection and graft rejection. Recent advances in tissue engineering have offered much promise in cartilage repair but the best cell source and in vitro system have not as yet been optimised. Human bone marrow mesenchymal stem cells (hBMSCs) have thus far been the cell of choice. However, we derived a unique stem cell from the human umbilical cord Wharton's jelly (hWJSC) that has properties superior to hBMSCs in terms of ready availability, prolonged stemness characteristics in vitro, high proliferation rates, wide multipotency, non-tumorigenicity and tolerance in allogeneic transplantation. We observed enhanced cell attachment, cell proliferation and chondrogenesis of hWJSCs over hBMSCs when grown on PCL/Collagen nanoscaffolds in the presence of a two-stage sequential complex/chondrogenic medium for 21 days. Improvement of these three parameters were confirmed via inverted optics, field emission scanning electron microscopy (FESEM), MTT assay, pellet diameters, Alcian blue histology and staining, glycosaminglycans (GAG) and hyaluronic acid production and expression of key chondrogenic genes (SOX9, Collagen type II, COMP, FMOD) using immunohistochemistry and real-time polymerase chain reaction (qRT-PCR). In separate experiments we demonstrated that the 16 ng/ml of basic fibroblast growth factor (bFGF) present in the complex medium may have contributed to driving chondrogenesis. We conclude that hWJSCs are an attractive stem cell source for inducing chondrogenesis in vitro when grown on nanoscaffolds and exposed sequentially first to complex medium and then followed by chondrogenic medium. PMID:21671058

  16. Grown-in defects and defects produced by 1-Me electron irradiated in Al0.3Ga0.7As P-N junction solar cells

    NASA Technical Reports Server (NTRS)

    Li, S. S.; Teng, K. W.; Schoenfeld, D. W.; Rahilly, W. P.

    1982-01-01

    Studies of grown-in defects and defects produced by the one-MeV electron irradiation in Al sub 0.3 Ga sub 0.7As p-n junction solar cells fabricated by liquid phase epitaxial (LPE) technique were made for the unirradiated and one-MeV electron irradiated samples, using DLTS and C-V methods. Defect and recombination parameters such as energy level, defect density, carrier capture cross sections and lifetimes were determined for various growth, annealing, and irradiation conditions.

  17. Mitochondria Increase Three-Fold and Mitochondrial Proteins and Lipid Change Dramatically in Postmeristematic Cells in Young Wheat Leaves Grown in Elevated CO2.

    PubMed Central

    Robertson, E. J.; Williams, M.; Harwood, J. L.; Lindsay, J. G.; Leaver, C. J.; Leech, R. M.

    1995-01-01

    A dramatic stimulation in mitochondrial biogenesis during the very early stages of leaf development was observed in young wheat plants (Triticum aestivum cv Hereward) grown in elevated CO2 (650 [mu]L L-1). An almost 3-fold increase in the number of mitochondria was observed in the very young leaf cells at the base of the first leaf of a 7-d-old wheat plant. In the same cells large increases in the accumulation of a mitochondrial chaperonin protein and the mitochondrial 2-oxoglutarate dehydrogenase complex and pyruvate dehydrogenase complex were detected by immunolabeling. Furthermore, the basal segment also shows a large increase in the rate of radiolabeling of diphosphatidylglycerol, a lipid confined to the inner mitochondrial membrane. This dramatic response in very young leaf cells to elevated CO2 suggests that the numerous documented positive effects of elevated CO2 on wheat leaf development are initiated as early as 12 h postmitosis. PMID:12228485

  18. Narrow band gap (1 eV) InGaAsSbN solar cells grown by metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Kim, T. W.; Garrod, T. J.; Kim, K.; Lee, J. J.; LaLumondiere, S. D.; Sin, Y.; Lotshaw, W. T.; Moss, S. C.; Kuech, T. F.; Tatavarti, Rao; Mawst, L. J.

    2012-03-01

    Heterojunction solar cell structures employing InGaAsSbN (Eg ˜ 1 eV) base regions are grown lattice-matched to GaAs substrates using metalorganic vapor phase epitaxy. Room temperature (RT) photoluminescence (PL) measurements indicate a peak spectral emission at 1.04 eV and carrier lifetimes of 471-576 ps are measured at RT from these structures using time-resolved PL techniques. Fabricated devices without anti-reflection coating demonstrate a peak efficiency of 4.58% under AM1.5 direct illumination. Solar cells with a 250 nm-thick InGaAsSbN base layer exhibit a 17% improvement in open circuit voltage (Voc), 14% improvement in fill factor, and 12% improvement in efficiency over the cells with a thicker (500 nm-thick) base layer.

  19. A vero cell derived combined vaccine against sheep pox and Peste des Petits ruminants for sheep.

    PubMed

    Chaudhary, S S; Pandey, K D; Singh, R P; Verma, P C; Gupta, P K

    2009-04-28

    The combined sheep pox and Peste des Petits ruminants (PPR) vaccine was prepared in lyophilized form containing recommended doses of both vaccine viruses. Safety and immunogenicity of this combined vaccine was evaluated in sheep. Sheep immunized subcutaneously with 1ml of live attenuated vaccine consisting of 10(3)TCID(50) each of sheep pox virus (SPV) Romanian Fanar (RF) strain and Peste des Petits ruminants virus (PPRV-Sungri/96 strain) were monitored for clinical and serological responses for a period of four weeks post immunization (pi) and two week post challenge (pc). Specific antibodies directed to sheep pox virus could be demonstrated by indirect ELISA and serum neutralization test (SNT). Competitive ELISA and SNT were used for demonstration of antibodies to PPR virus. All the immunized animals resisted challenge with virulent SPV or PPRV on day 30pi, while control animals developed characteristic signs of disease. Specific virus could be detected in the unvaccinated control animals after challenge but not from any of the immunized sheep. Combined vaccine was found to be safe and potent as evident from sero conversion as well as challenge studies in sheep. This indicates that component vaccines did not interfere each other and can be used in target population for economic vaccination strategies. PMID:19428860

  20. Comparison of single junction AlGaInP and GaInP solar cells grown by molecular beam epitaxy

    SciTech Connect

    Masuda, T; Tomasulo, S; Lang, JR; Lee, ML

    2015-03-07

    We have investigated similar to 2.0 eV (AlxGa1-x)(0.51)In0.49P and similar to 1.9 eV Ga0.51In0.49P single junction solar cells grown on both on-axis and misoriented GaAs substrates by molecular beam epitaxy (MBE). Although lattice-matched (AlxGa1-x)(0.51)In0.49P solar cells are highly attractive for space and concentrator photovoltaics, there have been few reports on the MBE growth of such cells. In this work, we demonstrate open circuit voltages (V-oc) ranging from 1.29 to 1.30 V for Ga0.51In0.49P cells, and 1.35-1.37 V for (AlxGa1-x)(0.51)In0.49P cells. Growth on misoriented substrates enabled the bandgap-voltage offset (W-oc = E-g/q - V-oc) of Ga0.51In0.49P cells to decrease from similar to 575 mV to similar to 565 mV, while that of (AlxGa1-x)(0.51)In0.49P cells remained nearly constant at 620 mV. The constant Woc as a function of substrate offcut for (AlxGa1-x)(0.51)In0.49P implies greater losses from non-radiative recombination compared with the Ga0.51In0.49P devices. In addition to larger Woc values, the (AlxGa1-x)(0.51)In0.49P cells exhibited significantly lower internal quantum efficiency (IQE) values than Ga0.51In0.49P cells due to recombination at the emitter/window layer interface. A thin emitter design is experimentally shown to be highly effective in improving IQE, particularly at short wavelengths. Our work shows that with further optimization of both cell structure and growth conditions, MBE-grown (AlxGa1-x)(0.51)In0.49P will be a promising wide-bandgap candidate material for high-efficiency, lattice-matched multi-junction solar cells. (C) 2015 AIP Publishing LLC.

  1. Significant changes in cell and chloroplast development in young wheat leaves (Triticum aestivum cv Hereward) grown in elevated CO{sub 2}

    SciTech Connect

    Robertson, E.J.; Leech, R.M.

    1995-01-01

    Cell and chloroplast development were characterized in young Triticum aestivum cv Hereward leaves grown at ambient (350 {mu}L L{sup {minus}1}) or at elevated (650 {mu}L L{sup {minus}1}) CO{sub 2}. In elevated CO{sub 2}, cell and chloroplast expansion was accelerated by 10 and 25%, respectively, in the first leaf of 7-d-old wheat plants without disruption to the leaf developmental pattern. Elevated CO{sub 2} did not affect the number of chloroplasts in relation to mesophyll cell size or the linear relationship between chloroplast number or size and mesophyll cell size. No major changes in leaf anatomy or in chloroplast ultrastructure were detected as a result of growth in elevated CO{sub 2}, but there was a marked reduction in starch accumulation. In leaf sections fluorescently tagged antisera were used to visualize and quantitate the amount of cytochrome f, the {alpha}- and {beta}-subunits of the coupling factor 1 in ATP synthase, D1 protein of the photosystem II reaction center, the 33-kD protein of the extrinsic oxygen-evolving complex, subunit II of photosystem I, and ribulose-1,5-biphosphate carboxylase/oxygenase. A significant finding was that in 10 to 20% of the mesophyll cells grown in elevated CO{sub 2} the 33-kD protein of the extrinsic oxygen-evolving complex of photosystem II and cytochrome f were deficient by 75%, but the other proteins accumulated normally. 29 refs., 6 figs., 2 tabs.

  2. Clostridium difficile Cell Attachment Is Modified by Environmental Factors

    PubMed Central

    Waligora, Anne-Judith; Barc, Marie-Claude; Bourlioux, Pierre; Collignon, Anne; Karjalainen, Tuomo

    1999-01-01

    Adherence of Clostridium difficile to Vero cells under anaerobic conditions was increased by a high sodium concentration, calcium-rich medium, an acidic pH, and iron starvation. The level of adhesion of nontoxigenic strains was comparable to that of toxigenic strains. Depending on the bacterial culture conditions, Vero cells could bind to one, two, or three bacterial surface proteins with molecular masses of 70, 50, and 40 kDa. PMID:10473442

  3. A longitudinal study of Vero cytotoxin producing Escherichia coli in cattle calves in Sri Lanka.

    PubMed Central

    Tokhi, A. M.; Peiris, J. S.; Scotland, S. M.; Willshaw, G. A.; Smith, H. R.; Cheasty, T.

    1993-01-01

    Two cohorts of 10 and 16 calves were followed at weekly or fortnightly intervals from 4-28 and 1-9 weeks respectively to determine whether natural infection by Vero cytotoxin (VT) producing Escherichia coli (VTEC) occurred. Ninety-one of 171 (53%) faecal specimens were VTEC positive and 20-80% of animals at any given time excreted VTEC. Of 104 VTEC strains studied further, 6 different serogroups (O 22.H16; O 25.H5; O 49.H-; O 86.H26; O 88.H25; O 153.H12) and an untypable strain (O? .H21) were identified. All strains belonging to the same serotype had identical profiles of reactivity with DNA probes to toxins VT1 or 2, LTI or II and a probe (CVD419) derived from a plasmid carried by enterohaemorrhagic Escherichia coli O 157.H7. Four of these serotypes were found in the faecal flora of the calves, taken as a group, throughout the 4-month study period. Sixty percent of the strains hybridized with the probe for VT1, 4% with the probe for VT2, and 36% with both probes. Faecal VTEC were significantly associated with overt diarrhoeal illness in animals < 10 weeks of age, but no characteristic profile of markers (serotype or hybridization pattern) in E. coli isolates was associated with diarrhoea. A serological response to VT1 was detected in some animals, but faecal VT1 VTEC excretion persisted in spite of seroconversion. VT1 seroconversion was not associated with diarrhoea. A serological response to VT2 was not detected even in those animals excreting VT2 VTEC in the faeces. PMID:8472764

  4. Properties of Retinal Precursor Cells Grown on Vertically Aligned Multiwalled Carbon Nanotubes Generated for the Modification of Retinal Implant-Embedded Microelectrode Arrays.

    PubMed

    Johnen, Sandra; Meißner, Frank; Krug, Mario; Baltz, Thomas; Endler, Ingolf; Mokwa, Wilfried; Walter, Peter

    2016-01-01

    Background. To analyze the biocompatibility of vertically aligned multiwalled carbon nanotubes (MWCNT), used as nanomodification to optimize the properties of prostheses-embedded microelectrodes that induce electrical stimulation of surviving retinal cells. Methods. MWCNT were synthesized on silicon wafers. Their growth was achieved by iron particles (Fe) or mixtures of iron-platinum (Fe-Pt) and iron-titanium (Fe-Ti) acting as catalysts. Viability, growth, adhesion, and gene expression of L-929 and retinal precursor (R28) cells were analyzed after nondirect and direct contact. Results. Nondirect contact had almost no influence on cell growth, as measured in comparison to reference materials with defined levels of cytotoxicity. Both cell types exhibited good proliferation properties on each MWCNT-coated wafer. Viability ranged from 95.9 to 99.8%, in which better survival was observed for nonfunctionalized MWCNT generated with the Fe-Pt and Fe-Ti catalyst mixtures. R28 cells grown on the MWCNT-coated wafers showed a decreased gene expression associated with neural and glial properties. Expression of the cell cycle-related genes CCNC, MYC, and TP53 was slightly downregulated. Cultivation on plasma-treated MWCNT did not lead to additional changes. Conclusions. All tested MWCNT-covered slices showed good biocompatibility profiles, confirming that this nanotechnology is a promising tool to improve prostheses bearing electrodes which connect with retinal tissue. PMID:27200182

  5. Properties of Retinal Precursor Cells Grown on Vertically Aligned Multiwalled Carbon Nanotubes Generated for the Modification of Retinal Implant-Embedded Microelectrode Arrays

    PubMed Central

    Johnen, Sandra; Meißner, Frank; Krug, Mario; Baltz, Thomas; Endler, Ingolf; Mokwa, Wilfried; Walter, Peter

    2016-01-01

    Background. To analyze the biocompatibility of vertically aligned multiwalled carbon nanotubes (MWCNT), used as nanomodification to optimize the properties of prostheses-embedded microelectrodes that induce electrical stimulation of surviving retinal cells. Methods. MWCNT were synthesized on silicon wafers. Their growth was achieved by iron particles (Fe) or mixtures of iron-platinum (Fe-Pt) and iron-titanium (Fe-Ti) acting as catalysts. Viability, growth, adhesion, and gene expression of L-929 and retinal precursor (R28) cells were analyzed after nondirect and direct contact. Results. Nondirect contact had almost no influence on cell growth, as measured in comparison to reference materials with defined levels of cytotoxicity. Both cell types exhibited good proliferation properties on each MWCNT-coated wafer. Viability ranged from 95.9 to 99.8%, in which better survival was observed for nonfunctionalized MWCNT generated with the Fe-Pt and Fe-Ti catalyst mixtures. R28 cells grown on the MWCNT-coated wafers showed a decreased gene expression associated with neural and glial properties. Expression of the cell cycle-related genes CCNC, MYC, and TP53 was slightly downregulated. Cultivation on plasma-treated MWCNT did not lead to additional changes. Conclusions. All tested MWCNT-covered slices showed good biocompatibility profiles, confirming that this nanotechnology is a promising tool to improve prostheses bearing electrodes which connect with retinal tissue. PMID:27200182

  6. Development of an IR-transparent, inverted-grown, thin-film, Al[sub 0. 34]Ga[sub 0. 66]As/GaAs cascade solar cell

    SciTech Connect

    Venkatasubramanian, R.; Timmons, M.L.; Sharps, P.R.; Colpitts, T.S.; Hills, J.S.; Hancock, J.; Hutchby, J.A. )

    1992-12-01

    Inverted growth and the development of associated cell processing, are likely to offer a significant degree of freedom for improving the performance of many III-V multijunction cascades and open new avenues for advanced multijunction concepts. This is especially true for the development of high-efficiency Al[sub 0.37]Ga[sub 0.63]As/GaAs cascades where the high growth temperatures required for the AlGaAs top cell growth can cause the deterioration of the tunnel junction interconnect. In the approach of inverted-grown AlGaAs/GaAs cascade cells, the AlGaAs top cell is grown first at 780 [degree]C and the GaAs tunnel junction and bottom cell are grown at 675 [degree]C. After the inverted growth, the AlGaAs/GaAs cascade structure is selectively removed from the parent substrate. The feasibility of inverted growth is demonstrated by a fully-processed, inverted-grown, thin film GaAs cell with a 1-sun AM1.5 efficiency of 20.3%. Also, an inverted-grown, thin-film, Al[sub 0.34]Ga[sub 0.66]As/GaAs cascade with AM1.5 efficiencies of 19.9% and 21% at 1-sun and 7-suns, respectively, has been obtained.

  7. GROWTH CHARACTERISTICS, MORPHOLOGY, AND PHOSPHOLIPID COMPOSITION OF HUMAN TYPE 2 PULMONARY ALVEOLAR CELLS GROWN IN A COLLAGEN-FREE MICROENVIRONMENT

    EPA Science Inventory

    Human lung epithelial cells have been cultured and characterized for phospholipid content. Any residual fibroblasts were removed by selective trypsinization within the first 48 hours in culture. Epithelial cells were serially subpassaged when cultures reached ca. 80% confluency. ...

  8. Factors derived from Escherichia coli Nissle 1917, grown in different growth media, enhance cell death in a model of 5-fluorouracil-induced Caco-2 intestinal epithelial cell damage.

    PubMed

    Wang, Hanru; Bastian, Susan E P; Lawrence, Andrew; Howarth, Gordon S

    2015-01-01

    We evaluated supernatants (SNs) from Escherichia coli Nissle 1917 (EcN) grown in commonly used growth media for their capacity to affect the viability of Caco-2 colon cancer cells in the presence and absence of 5-Fluorouracil (5-FU) chemotherapy. EcN was grown in Luria-Bertani (LB), tryptone soya (TSB), Man Rogosa Sharpe (MRS), and M17 broth supplemented with 10% (v/v) lactose solution (M17). Human Caco-2 colon cancer cells were treated with DMEM (control), growth media alone (LB, TSB, MRS, and M17) or EcN SNs derived from these 4 media, in the presence and absence of 5-FU. Cell viability, reactive oxygen species (ROS), and cell monolayer permeability were determined. EcN SN in LB medium reduced Caco-2 cell viability significantly, to 51% at 48 h. The combination of this EcN SN and 5-FU further reduced cell viability to 37% at 48 h, compared to 5-FU control. MRS broth and EcN SN in MRS, together with 5-FU, generated significantly lower levels of ROS compared to 5-FU control. However, all 5-FU treatments significantly disrupted the Caco-2 cell barrier compared to control; with no significant differences observed among any of the 5-FU treatments. EcN SNs (LB+) was most effective at decreasing the viability of Caco-2 cells. This could indicate a potential role for this EcN SN in chemoprevention for colon cancer. PMID:25625670

  9. Aromatase in the human choriocarcinoma JEG-3: inhibition by R 76 713 in cultured cells and in tumors grown in nude mice.

    PubMed

    Krekels, M D; Wouters, W; De Coster, R; Van Ginckel, R; Leonaers, A; Janssen, P A

    1991-04-01

    The aromatase enzyme and its inhibition by R 76 713 were characterized in the JEG-3 choriocarcinoma cell line in culture and in JEG-3 tumors grown in nude mice. Optimal cell culture parameters and enzyme reaction conditions for the determination of aromatase activity were established. Under these conditions, in vitro JEG-3 aromatase was inhibited by R 76 713 with IC50-values of 7.6 +/- 0.5 nM and 2.7 +/- 1.1 nM using 500 nM of androstenedione and testosterone as substrate respectively. The Km-value of the aromatase enzyme with androstenedione as substrate was 62 +/- 19 nM; with testosterone as substrate, a value of 166 +/- 27 nM was found. In the presence of increasing concentrations of R 76 713, the Km-values increased while the Vmax remained unchanged. Using androstenedione and testosterone as substrate Lineweaver-Burk analysis of the data showed Ki-values for R 76 713 of 0.43 +/- 0.06 nM and 0.47 +/- 0.39 nM respectively. R 76 713 appeared to competitively inhibit the JEG-3 aromatase. Aromatase could easily be measured in homogenates of JEG-3 tumors grown in nude mice and showed Km-values similar to those found for JEG-3 cells in vitro. IC50-values for inhibition of tumor aromatase by R 76 713 were also similar to those found in cultured cells. Tumor aromatase measured ex vivo, 2 h after a single oral administration of R 76 713 was dose-dependently inhibited. An ED50-value of 0.05 mg/kg was calculated. The JEG-3 choriocarcinoma proved to be a useful aromatase model enabling the comparative study of aromatase inhibition in vitro and in vivo. PMID:2031856

  10. Cell wall changes in nisin-resistant variants of Listeria innocua grown in the presence of high nisin concentrations.

    PubMed

    Maisnier-Patin, S; Richard, J

    1996-06-15

    Two nisin-resistant variants of a strain of Listeria innocua were isolated after growth in the presence of 500 and 4000 IU ml-1 of nisin A showed increased cell wall hydrophobicity, resistance to phage attack and three different cell wall-acting antibiotics, as well as to the peptidoglycan hydrolytic enzymes lysozyme and mutanolysin, as compared to the parental strain. Transmission electron microscopy revealed marked thickening of the wall of nisin-resistant cells with an irregular surface. Differences in thickness were lost after cell wall purification and no significant difference in gross wall composition was observed between the parental and resistant variants. Cell wall changes in nisin-resistant listeriae are attributed to abnormal cell wall synthesis and autolysin inhibition, the latter possibly associated with subtle changes in cell wall structures and function. PMID:8666198

  11. Effect of temperature and pH on ethanol production by free and immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract

    SciTech Connect

    Bajpai, P.; Margaritis, A.

    1987-01-01

    The effect of temperature and pH on the kinetics of ethanol production by free and calcium alginate immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract was investigated. With the free cells, the ethanol and biomass yields were relatively constant over the temperature range 25-35 degrees C, but dropped sharply beyond 35 degrees C. Other kinetic parameters, specific growth rate, specific ethanol production rate, and specific total sugar uptake rate were maximum at 35 degrees C. However, with the immobilized cells, ethanol yield remained almost constant in the temperatue range 25-45 degrees C, and the specific ethanol production rate and specific total sugar uptake rate attained their maximum values at 40 degrees C. For the pH range between 3 and 7, the free-cell optimum for growth and product formation was found to be circa pH 5. At this pH, the specific growth rate was 0.35/h and specific ethanol production rate was 2.83 g/g/h. At values higher or lower than pH 5, a sharp decrease in specific ethanol production rate as well as specific growth rate was observed. In comparison, the immobilized cells showed a broad optimum pH profile. The best ethanol production rates were observed between pH 4 and 6. (Refs. 22).

  12. Structural Complexity of Non-acid Glycosphingolipids in Human Embryonic Stem Cells Grown under Feeder-free Conditions*

    PubMed Central

    Barone, Angela; Benktander, John; Ångström, Jonas; Aspegren, Anders; Björquist, Petter; Teneberg, Susann; Breimer, Michael. E.

    2013-01-01

    Due to their pluripotency and growth capability, there are great expectations for human embryonic stem cells, both as a resource for functional studies of early human development and as a renewable source of cells for use in regenerative medicine and transplantation. However, to bring human embryonic stem cells into clinical applications, their cell surface antigen expression and its chemical structural complexity have to be defined. In the present study, total non-acid glycosphingolipid fractions were isolated from two human embryonic stem cell lines (SA121 and SA181) originating from leftover in vitro fertilized human embryos, using large amounts of starting material (1 × 109 cells/cell line). The total non-acid glycosphingolipid fractions were characterized by antibody and lectin binding, mass spectrometry, and proton NMR. In addition to the globo-series and type 1 core chain glycosphingolipids previously described in human embryonic stem cells, a number of type 2 core chain glycosphingolipids (neo-lactotetraosylceramide, the H type 2 pentaosylceramide, the Lex pentaosylceramide, and the Ley hexaosylceramide) were identified as well as the blood group A type 1 hexaosylceramide. Finally, the mono-, di-, and triglycosylceramides were characterized as galactosylceramide, glucosylceramide, lactosylceramide, galabiaosylceramide, globotriaosylceramide, and lactotriaosylceramide. Thus, the glycan diversity of human embryonic stem cells, including cell surface immune determinants, is more complex than previously appreciated. PMID:23404501

  13. Elastic hydrogel as a sensor for detection of mechanical stress generated by single cells grown in three-dimensional environment.

    PubMed

    Huang, Jianyong; Wang, Liangli; Xiong, Chunyang; Yuan, Fan

    2016-08-01

    Cell volume growth occurs in all living tissues. The growth exerts mechanical stresses on surrounding tissues that may alter tissue microenvironment, and have significant implications in health and diseases. However, the level of growth stress generated by single cells in three-dimensional (3D) environment remains to be determined. To this end, we developed a growth force microscopy technique to determine 3D distribution of the stress. The technique was based on encapsulation of cells in elastic hydrogels, and involved 3D particle tracking and mechanical analysis of gel deformation. Data from the study demonstrated that the growth stress was dynamic, and the stress distribution at the gel-cell interface was correlated inversely to the mean surface curvature or the distance to the geometric center of the cell. The stress averaged over the cell surface increased with increasing gel stiffness, suggesting that cells could alter growth stress in response to stiffness change in microenvironment. These findings suggested that the elastic hydrogel-based microscopy technique had a potential to provide new insights into mechanisms of mechanical interactions between cell and its microenvironment. PMID:27182812

  14. Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

    NASA Technical Reports Server (NTRS)

    Choi, K. J.; Nakhost, Z.; Barzana, E.; Karel, M.

    1987-01-01

    The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.

  15. Improved Performance of GaInNAs Solar Cells Grown by Molecular-Beam Epitaxy Using Increased Growth Rate Instead of Surfactants

    SciTech Connect

    Ptak, A. J.; France, R.; Jiang, C. S.; Romero, M. J.

    2009-01-01

    GaInNAs is potentially useful for increasing the conversion efficiency of multijunction solar cells if low photocurrents and photovoltages can be increased. Wide-depletion width devices generate significant photocurrents using an n-i-p structure grown by molecular-beam epitaxy, but these wide depletion widths are only realized in a region of parameter space that leads to rough surface morphologies. Surfactants are effective at reducing the surface roughness, but lead to increased defect densities and changes in the net acceptor or donor concentration. Here, we show that increasing the growth rate of GaInNAs solar cells leads to smooth surfaces without the use of a surfactant, even at high In compositions and substrate temperatures. No degradation in material quality is observed when increasing the growth rate from 1.5 to 3.0 {micro}m/h, but a shunt resistance does appear for the high-growth-rate samples. This shunt is attributed to increased spitting of the Ga cell, leading to an increase in the oval defect density, at the higher effusion cell temperatures used to achieve high growth rates. As with the case of Bi in GaInNAs, increased growth rates also appear to increase the net donor concentration, but it is not clear if these effects have the same cause.

  16. Human RPE Stem Cells Grown into Polarized RPE Monolayers on a Polyester Matrix Are Maintained after Grafting into Rabbit Subretinal Space

    PubMed Central

    Stanzel, Boris V.; Liu, Zengping; Somboonthanakij, Sudawadee; Wongsawad, Warapat; Brinken, Ralf; Eter, Nicole; Corneo, Barbara; Holz, Frank G.; Temple, Sally; Stern, Jeffrey H.; Blenkinsop, Timothy A.

    2014-01-01

    Summary Transplantation of the retinal pigment epithelium (RPE) is being developed as a cell-replacement therapy for age-related macular degeneration. Human embryonic stem cell (hESC) and induced pluripotent stem cell (iPSC)-derived RPE are currently translating toward clinic. We introduce the adult human RPE stem cell (hRPESC) as an alternative RPE source. Polarized monolayers of adult hRPESC-derived RPE grown on polyester (PET) membranes had near-native characteristics. Trephined pieces of RPE monolayers on PET were transplanted subretinally in the rabbit, a large-eyed animal model. After 4 days, retinal edema was observed above the implant, detected by spectral domain optical coherence tomography (SD-OCT) and fundoscopy. At 1 week, retinal atrophy overlying the fetal or adult transplant was observed, remaining stable thereafter. Histology obtained 4 weeks after implantation confirmed a continuous polarized human RPE monolayer on PET. Taken together, the xeno-RPE survived with retained characteristics in the subretinal space. These experiments support that adult hRPESC-derived RPE are a potential source for transplantation therapies. PMID:24511471

  17. Failure of propagation of human norovirus in intestinal epithelial cells with microvilli grown in three-dimensional cultures

    PubMed Central

    Takanashi, Sayaka; Saif, Linda J.; Hughes, John H.; Meulia, Tea; Jung, Kwonil; Scheuer, Kelly A.; Wang, Qiuhong

    2013-01-01

    Human noroviruses (HuNoVs) are a leading cause of acute gastroenteritis. Establishment of a cell culture system for in vitro HuNoV growth remains challenging. Replication of HuNoVs in human intestinal cell lines (INT-407 and Caco-2) that differentiate to produce microvilli in rotation wall vessel (RWV) three-dimensional cultures has been reported (Straub et al., Emerg Infect Dis 13:396–403 2007, J Water Health 9:225–240 2011, and Water Sci Technol 67:863–868 2013). We used a similar RWV system, intestinal cell lines, and the same (Genogroup [G] I.1) plus additional (GII.4 and GII.12) HuNoV strains to test the system’s reproducibility and to expand the earlier findings. Apical microvilli were observed on the surface of both cell lines by light and electron microscopy. However, none of the cell types tested resulted in productive viral replication of any of the HuNoV strains, as confirmed by plateau or declining viral RNA titers in the supernatants and cell lysates of HuNoV-infected cells, determined by real-time reverse transcription PCR. These trends were the same when culture supplements were added that have been reported to be effective for replication of other fastidious enteric viruses in vitro. Additionally, by confocal microscopy and orthoslice analysis, viral capsid proteins were mainly observed above the actin filament signals, which suggested that the majority of viral antigens were on the cell surface. We conclude that even intestinal cells displaying microvilli were not sufficient to support HuNoV replication under the conditions tested. PMID:23974469

  18. Stability of single and tandem junction a-Si:H solar cells grown using the ECR process

    SciTech Connect

    Dalal, V.L.; Maxson, T.; Girvan, R.; Haroon, S.

    1997-07-01

    The authors report on the fabrication and stability tests of single junction a-Si:H, and tandem junction a-Si:H/A-Si:H solar cells using the ECR process under high hydrogen dilution (H-ECR process). They show that devices with high fill factors can be made using the H-ECR process. They also report on the stability studies of the solar cells under 1 and 2-sun illumination conditions. The solar cells show very little degradation even after 500 hours of illumination under 2 x sunlight illumination.

  19. Differences in excitation energy transfer of Arthrospira platensis cells grown in seawater medium and freshwater medium, probed by time-resolved fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Arba, Muhammad; Aikawa, Shimpei; Niki, Kenta; Yokono, Makio; Kondo, Akihiko; Akimoto, Seiji

    2013-11-01

    Excitation energy transfer of Arthrospira platensis cells grown in f/2 medium (a high salinity medium) and SOT medium (a control) was investigated by steady-state and time-resolved spectroscopies. Growth in f/2 medium induced changes in absorption and fluorescence spectra as well as in the energy transfer pathways. Excitation energy captured by phycobilisome (PBS) was transferred directly to photosystem (PS) I, instead of being first transferred to an intermediate (PBS → PSII → PSI), as observed in SOT medium. The respiration rate increased while photosynthetic rate reduced in f/2 medium. Possible causes of the differences in light-harvesting and energy-transfer processes between the two media are discussed.

  20. The light intensity under which cells are grown controls the type of peripheral light-harvesting complexes that are assembled in a purple photosynthetic bacterium

    SciTech Connect

    Brotosudarmo, Tatas H. P.; Collins, Aaron M.; Gall, Andrew; Roszak, Aleksander W.; Gardiner, Alastair T.; Blankenship, Robert E.; Cogdell, Richard J.

    2011-11-15

    The differing composition of LH2 (peripheral light-harvesting) complexes present in Rhodopseudomonas palustris 2.1.6 have been investigated when cells are grown under progressively decreasing light intensity. Analysis of the absorption spectra reveals there must be more than two types of LH2 complexes present. Purified HL (high-light) and LL (low-light) LH2 complexes have mixed apoprotein compositions. The HL complexes contain PucABa and PucABb apoproteins. The LL complexes contain PucABa, PucABd and PucBb-only apoproteins. This mixed apoprotein composition can explain their resonance Raman spectra.

  1. Inactivated rabies vaccine produced from the Flury LEP strain of virus grown in BHK-21 suspension cells.

    PubMed

    Chapman, W G; Ramshaw, I A; Crick, J

    1973-12-01

    Suspension cultures of BHK-21 cells maintained at 32 to 33 C were infected with the Flury LEP strain of rabies virus. By using a cell concentration of 2.0 x 10(6) to 2.5 x 10(6) cells per ml infected at a multiplicity of 0.05, high titers of extracellular virus were reached in 96 to 120 h, and potent inactivated vaccines were prepared from culture fluids harvested between 96 to 168 h. The addition of 1% bovine serum to the maintenance medium resulted in an increase in virus yields and vaccine potency. Estimation of the number of infected cells by immunofluorescent procedures proved a rapid and reliable guide to the virus content of suspension cultures. PMID:4588193

  2. Differences In Early T-Cell Signaling In Cultures Grown In a Rotating Clinostat vs. Static Controls

    NASA Technical Reports Server (NTRS)

    Alexamder. M.; Nelman-Gonzales, M.; Penkala, J.; Sams, C.

    1999-01-01

    Altered gravity has previously been demonstrated to be a stress that can influence components of the immune system. Specifically, T-cell activation has been shown to be affected by changes in gravity, exhibiting a decrease in proliferative response to in vitro stimulation in microgravity. Subsequent ground based studies utilizing a rotating clinostat to model some of the effects of microgravity have been consistent with earlier flight based experiments. These ground and flight experiments have examined T-cell activation by measuring various responses including production of cytokines, DNA synthesis and the production of various cell surface activation markers. These indicators of T-cell activation were measured anywhere from 4 to 72 hours after stimulation. Prior to the work described here, the initial signaling events in T-cell activation had not been directly examined. The goal of this project was to determine how the process of early signal transduction was affected by growth in a rotating clinostat. Here we directly show a defect in signaling from TCR to MAPK in purified peripheral T-cells activated in the clinostat by OKT3/antiCD28 coated microbeads as compared to static controls.

  3. The polyGeVero® software for fast and easy computation of 3D radiotherapy dosimetry data

    NASA Astrophysics Data System (ADS)

    Kozicki, Marek; Maras, Piotr

    2015-01-01

    The polyGeVero® software package was elaborated for calculations of 3D dosimetry data such as the polymer gel dosimetry. It comprises four workspaces designed for: i) calculating calibrations, ii) storing calibrations in a database, iii) calculating dose distribution 3D cubes, iv) comparing two datasets e.g. a measured one with a 3D dosimetry with a calculated one with the aid of a treatment planning system. To accomplish calculations the software was equipped with a number of tools such as the brachytherapy isotopes database, brachytherapy dose versus distance calculation based on the line approximation approach, automatic spatial alignment of two 3D dose cubes for comparison purposes, 3D gamma index, 3D gamma angle, 3D dose difference, Pearson's coefficient, histograms calculations, isodoses superimposition for two datasets, and profiles calculations in any desired direction. This communication is to briefly present the main functions of the software and report on the speed of calculations performed by polyGeVero®.

  4. Does vector-free gravity simulate microgravity? Functional and morphologic attributes of clinorotated nerve and muscle grown in cell culture

    NASA Technical Reports Server (NTRS)

    Gruener, R.; Hoeger, G.

    1988-01-01

    Cocultured Xenopus neurons and myocytes were subjected to non-vectorial gravity by clinostat rotation to determine if microgravity, during space flights, may affect cell development and communications. Clinorotated cells showed changes consistent with the hypothesis that cell differentiation, in microgravity, is altered by interference with cytoskeleton-related mechanisms. We found: increases in the myocyte and its nuclear area, "fragmentation" of nucleoli, appearance of neuritic "aneurysms", decreased growth in the presence of "trophic" factors, and decreased yolk utilization. The effects were most notable at 1-10 rpm and depended on the onset and duration of rotation. Some parameters returned to near control values within 48 hrs after cessation of rotation. Cells from cultures rotated at higher speeds (>50 rpm) appeared comparable to controls. Compensation by centrifugal forces may account for this finding. Our data are consistent, in principle, with effects on other, flighted cells and suggest that "vector-free" gravity may simulate certain aspects of microgravity. The distribution of acetylcholine receptor aggregates, on myocytes, was also altered. This indicates that brain development, in microgravity, may also be affected.

  5. Comparison of single junction AlGaInP and GaInP solar cells grown by molecular beam epitaxy

    SciTech Connect

    Masuda, Taizo Tomasulo, Stephanie; Lang, Jordan R.; Lee, Minjoo Larry

    2015-03-07

    We have investigated ∼2.0 eV (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P and ∼1.9 eV Ga{sub 0.51}In{sub 0.49}P single junction solar cells grown on both on-axis and misoriented GaAs substrates by molecular beam epitaxy (MBE). Although lattice-matched (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P solar cells are highly attractive for space and concentrator photovoltaics, there have been few reports on the MBE growth of such cells. In this work, we demonstrate open circuit voltages (V{sub oc}) ranging from 1.29 to 1.30 V for Ga{sub 0.51}In{sub 0.49}P cells, and 1.35–1.37 V for (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P cells. Growth on misoriented substrates enabled the bandgap-voltage offset (W{sub oc} = E{sub g}/q − V{sub oc}) of Ga{sub 0.51}In{sub 0.49}P cells to decrease from ∼575 mV to ∼565 mV, while that of (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P cells remained nearly constant at 620 mV. The constant W{sub oc} as a function of substrate offcut for (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P implies greater losses from non-radiative recombination compared with the Ga{sub 0.51}In{sub 0.49}P devices. In addition to larger W{sub oc} values, the (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P cells exhibited significantly lower internal quantum efficiency (IQE) values than Ga{sub 0.51}In{sub 0.49}P cells due to recombination at the emitter/window layer interface. A thin emitter design is experimentally shown to be highly effective in improving IQE, particularly at short wavelengths. Our work shows that with further optimization of both cell structure and growth conditions, MBE-grown (Al{sub x}Ga{sub 1−x}){sub 0.51}In{sub 0.49}P will be a promising wide-bandgap candidate material for high-efficiency, lattice-matched multi-junction solar cells.

  6. Comparison of IgG diffusion and extracellular matrix composition in rhabdomyosarcomas grown in mice versus in vitro as spheroids reveals the role of host stromal cells

    PubMed Central

    Davies, C de L; Berk, D A; Pluen, A; Jain, R K

    2002-01-01

    The tumour extracellular matrix acts as a barrier to the delivery of therapeutic agents. To test the hypothesis that extracellular matrix composition governs the penetration rate of macromolecules in tumour tissue, we measured the diffusion coefficient of nonspecific IgG in three rhabdomyosarcoma subclones growing as multicellular spheroids in vitro or as subcutaneous tumours in dorsal windows in vivo. In subcutaneous tumours, the diffusion coefficient decreased with increasing content of collagen and sulphated glycosaminoglycans. When grown as multicellular spheroids, no differences in either extracellular matrix composition or diffusion coefficient were found. Comparison of in vitro vs in vivo results suggests an over-riding role of host stromal cells in extracellular matrix production subjected to modulation by tumour cells. Penetration of therapeutic macromolecules through tumour extracellular matrix might thus be largely determined by the host organ. Hence, caution must be exercised in extrapolating drug penetrability from spheroids and multilayer cellular sandwiches consisting of only tumour cells to tumours in vivo. British Journal of Cancer (2002) 86, 1639–1644. DOI: 10.1038/sj/bjc/6600270 www.bjcancer.com © 2002 Cancer Research UK PMID:12085216

  7. High-Quality Perovskite Films Grown with a Fast Solvent-Assisted Molecule Inserting Strategy for Highly Efficient and Stable Solar Cells.

    PubMed

    Yuan, Shuai; Qiu, Zhiwen; Gao, Chaomin; Zhang, Hailiang; Jiang, Yanan; Li, Cuncheng; Yu, Jinghua; Cao, Bingqiang

    2016-08-31

    The performance of organolead halide perovskites based solar cells has been enhanced dramatically due to the morphology control of the perovskite films. In this paper, we present a fast solvent-assisted molecule inserting (S-AMI) strategy to grow high-quality perovskite film, in which the methylammonium iodide/2-propanol (MAI/IPA) solution is spin-coated onto a dimethylformamide (DMF) wetted mixed lead halide (PbX2) precursor film. The DMF can help the inserting of MAI molecules into the PbX2 precursor film and provide a solvent environment to help the grain growth of the perovskite film. The perovskite film grown by the S-AMI approach shows large and well-oriented grains and long carrier lifetime due to the reduced grain boundary. Solar cells constructed with these perovskite films yield an average efficiency over 17% along with a high average fill factor of 80%. Moreover, these unsealed solar cell devices exhibit good stability in an ambient atmosphere. PMID:27526617

  8. Maslinic Acid, a Triterpene from Olive, Affects the Antioxidant and Mitochondrial Status of B16F10 Melanoma Cells Grown under Stressful Conditions

    PubMed Central

    Mokhtari, Khalida; Rufino-Palomares, Eva E.; Pérez-Jiménez, Amalia; Reyes-Zurita, Fernando J.; Figuera, Celeny; García-Salguero, Leticia; Medina, Pedro P.; Peragón, Juan; Lupiáñez, José A.

    2015-01-01

    Maslinic acid (MA) is a natural compound whose structure corresponds to a pentacyclic triterpene. It is abundant in the cuticular lipid layer of olives. MA has many biological and therapeutic properties related to health, including antitumor, anti-inflammatory, antimicrobial, antiparasitic, antihypertensive, and antioxidant activities. However, no studies have been performed to understand the molecular mechanism induced by this compound in melanoma cancer. The objective of this study was to examine the effect of MA in melanoma (B16F10) cells grown in the presence or absence of fetal bovine serum (FBS). We performed cell proliferation measurements, and the reactive oxygen species (ROS) measurements using dihydrorhodamine 123 (DHR 123) and activities of catalase, glucose 6-phosphate dehydrogenase, glutathione S-transferase, and superoxide dismutase. These changes were corroborated by expression assays. FBS absence reduced cell viability decreasing IC50 values of MA. The DHR 123 data showed an increase in the ROS level in the absence of FBS. Furthermore, MA had an antioxidant effect at lower assayed levels measured as DHR and antioxidant defense. However, at higher dosages MA induced cellular damage by apoptosis as seen in the results obtained. PMID:26236377

  9. Maslinic Acid, a Triterpene from Olive, Affects the Antioxidant and Mitochondrial Status of B16F10 Melanoma Cells Grown under Stressful Conditions.

    PubMed

    Mokhtari, Khalida; Rufino-Palomares, Eva E; Pérez-Jiménez, Amalia; Reyes-Zurita, Fernando J; Figuera, Celeny; García-Salguero, Leticia; Medina, Pedro P; Peragón, Juan; Lupiáñez, José A

    2015-01-01

    Maslinic acid (MA) is a natural compound whose structure corresponds to a pentacyclic triterpene. It is abundant in the cuticular lipid layer of olives. MA has many biological and therapeutic properties related to health, including antitumor, anti-inflammatory, antimicrobial, antiparasitic, antihypertensive, and antioxidant activities. However, no studies have been performed to understand the molecular mechanism induced by this compound in melanoma cancer. The objective of this study was to examine the effect of MA in melanoma (B16F10) cells grown in the presence or absence of fetal bovine serum (FBS). We performed cell proliferation measurements, and the reactive oxygen species (ROS) measurements using dihydrorhodamine 123 (DHR 123) and activities of catalase, glucose 6-phosphate dehydrogenase, glutathione S-transferase, and superoxide dismutase. These changes were corroborated by expression assays. FBS absence reduced cell viability decreasing IC50 values of MA. The DHR 123 data showed an increase in the ROS level in the absence of FBS. Furthermore, MA had an antioxidant effect at lower assayed levels measured as DHR and antioxidant defense. However, at higher dosages MA induced cellular damage by apoptosis as seen in the results obtained. PMID:26236377

  10. High-efficiency Al sub 0. 22 Ga sub 0. 78 As solar cells grown by molecular beam epitaxy

    SciTech Connect

    Melloch, M.R. ); Tobin, S.P.; Bajgar, C. ); Keshavarzi, A.; Stellwag, T.B.; Lush, G.B.; Lundstrom, M.S. ); Emery, K. )

    1990-07-02

    The quality of {ital pn} junction photodetectors made of Al{sub 0.2}Ga{sub 0.8}As has been investigated as a first step in the optimization of tandem solar cells. We have obtained 1 sun AM1.5 efficiencies of 16.1% for 0.25 cm{sup 2} Al{sub 0.22}Ga{sub 0.78}As solar cells fabricated from molecular beam epitaxy (MBE) material. This efficiency is 3.2 percentage points higher than the previously best reported efficiency of 12.9% for an Al{sub 0.2}Ga{sub 0.8}As solar cell fabricated from MBE material.