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1

Production of Newcastle Disease Virus by Vero Cells Grown on Cytodex 1 Microcarriers in a 2-Litre Stirred Tank Bioreactor  

PubMed Central

The aim of this study is to prepare a model for the production of Newcastle disease virus (NDV) lentogenic F strain using cell culture in bioreactor for live attenuated vaccine preparation. In this study, firstly we investigated the growth of Vero cells in several culture media. The maximum cell number was yielded by culture of Vero cells in Dulbecco's Modified Eagle Medium (DMEM) which was 1.93 × 106?cells/ml. Secondly Vero cells were grown in two-litre stirred tank bioreactor by using several commercial microcarriers. We achieved the maximum cell concentration about 7.95 × 105?cells/ml when using Cytodex 1. Later we produced Newcastle Disease virus in stirred tank bioreactor based on the design developed using Taguchi L4 method. Results reveal that higher multiplicity of infection (MOI) and size of cell inoculums can yield higher virus titer. Finally, virus samples were purified using high-speed centrifugation based on 3??(3-1) Fractional Factorial Design. Statistical analysis showed that the maximum virus titer can be achieved at virus sample concentration of 58.45% (v/v), centrifugation speed of 13729?rpm, and centrifugation time of 4 hours. As a conclusion, high yield of virus titer could be achieved through optimization of cell culture in bioreactor and separation by high-speed centrifugation. PMID:20625497

Arifin, Mohd Azmir; Mel, Maizirwan; Abdul Karim, Mohamed Ismail; Ideris, Aini

2010-01-01

2

Purification and Characterization of Enterovirus 71 Viral Particles Produced from Vero Cells Grown in a Serum-Free Microcarrier Bioreactor System  

PubMed Central

Background Enterovirus 71 (EV71) infections manifest most commonly as a childhood exanthema known as hand-foot-and-mouth disease (HFMD) and can cause neurological disease during acute infection. Principal Finding In this study, we describe the production, purification and characterization of EV71 virus produced from Vero cells grown in a five-liter serum-free bioreactor system containing 5 g/L Cytodex 1 microcarrier. The viral titer was >106 TCID50/mL by 6 days post infection when a MOI of 10?5 was used at the initial infection. Two EV71 virus fractions were separated and detected when the harvested EV71 virus concentrate was purified by sucrose gradient zonal ultracentrifugation. The EV71 viral particles detected in the 24–28% sucrose fractions had an icosahedral structure 30–31 nm in diameter and had low viral infectivity and RNA content. Three major viral proteins (VP0, VP1 and VP3) were observed by SDS-PAGE. The EV71 viral particles detected in the fractions containing 35–38% sucrose were 33–35 nm in size, had high viral infectivity and RNA content, and were composed of four viral proteins (VP1, VP2, VP3 and VP4), as shown by SDS-PAGE analyses. The two virus fractions were formalin-inactivated and induced high virus neutralizing antibody responses in mouse immunogenicity studies. Both mouse antisera recognized the immunodominant linear neutralization epitope of VP1 (residues 211–225). Conclusion These results provide important information for cell-based EV71 vaccine development, particularly for the preparation of working standards for viral antigen quantification. PMID:21603631

Liu, Chia-Chyi; Guo, Meng-Shin; Lin, Fion Hsiao-Yu; Hsiao, Kuang-Nan; Chang, Kate Hsuen-Wen; Chou, Ai-Hsiang; Wang, Yu-Chao; Chen, Yu-Ching; Yang, Chung-Shi; Chong, Pele Choi-Sing

2011-01-01

3

Generation of vero cells expressing ebola virus glycoprotein.  

PubMed

To establish replication-incompetent Ebola virus (EBOV) lacking its glycoprotein (GP), we attempted to generate a Vero cell line that constitutively expressed GP. We used a retroviral vector to transduce Vero cells with the EBOV GP gene, resulting in a high expression level of GP on the cell surface. The Vero cells expressing EBOV GP complemented the replication cycle of vesicular stomatitis virus, which lacks the essential viral glycoprotein. This cell line might be useful for basic research on EBOV GP as well as for vaccine production. PMID:19420858

Makino, Akiko; Kawaoka, Yoshihiro

2009-04-01

4

Development of Vero Cell-Derived Inactivated Japanese Encephalitis Vaccine  

Microsoft Academic Search

We have established a manufacturing system for a Vero cell-derived inactivated Japanese encephalitis vaccine at a 500l scale. The production system involves expansion of Vero cells using microcarrier, followed by virus infection. Except for an additional purification step, the downstream purification processes are similar to those used for the current mouse brain-derived vaccine; cell removal, concentration and removal of low-molecular

Keishin Sugawara; Kiyoto Nishiyama; Yuji Ishikawa; Motoharu Abe; Kengo Sonoda; Kazuhiro Komatsu; Yoshikane Horikawa; Kengo Takeda; Tomitaka Honda; Shoji Kuzuhara; Yoichiro Kino; Hiroshi Mizokami; Kyosuke Mizuno; Tetsuya Oka; Kennosuke Honda

2002-01-01

5

Original article Beneficial effects of Vero cells for developing  

E-print Network

culture systems: monolayers or microdrops. Inseminated oocytes cocultured for 7 days with Vero cells transfer to 26 recipient heifers. Confirmed pregnancy rate after 3 months was 58%, demonstrating their high tubaires (BOEC), dans deux sys- tèmes de culture différents : monocouche ou microgoutte. En microgouttes

Paris-Sud XI, Université de

6

VERO cells (cercopithecus aethiops kidney) — growth characteristics and viral susceptibility for use in diagnostic virology  

Microsoft Academic Search

Summary An investigation of some of the characteristics of the VERO cell line (Cercopithecus aethiops kidney) is reported, in which the suitability of the cells for use in routine diagnostic virology was examined. VERO cells will:1.grow to monolayers as rapidly as other heteroploid cell lines, but will maintain as usable monolayers in conventional maintenance medium for a significantly longer time;2.grow

D. E. Macfarlane; R. G. Sommerville

1969-01-01

7

Establishment and Maintenance of Persistent Infection by the Phlebovirus Toscana in Vero Cells  

Microsoft Academic Search

SUMMARY Persistent infections were established by serial undiluted passages of the Toscana virus of the genus Phlebovirus in Vero cells. Persistence was maintained through more than 70 passages over a period of 2 years. The persistently infected cells were morphologically similar to the parental Vero cells and released variable amounts of infectious virus. A small percentage of the persistently infected

P. Verani; L. Nicoletti; A. Marchi

1984-01-01

8

Improved plaque assays for Rickettsia prowazekii in Vero 76 cells.  

PubMed Central

Typhus group rickettsiae, including Rickettsia prowazekii and R. typhi, produce visible plaques on primary chick embryo fibroblasts and low-passage mouse embryo fibroblasts but do not form reproducible plaques on continuous cell culture lines. We tested medium overlay modifications for plaque formation of typhus group rickettsiae on the continuous fibroblast cell line Vero76. A procedure involving primary overlay with medium at pH 6.8, which was followed 2 to 3 days later with secondary overlay at neutral pH containing 1 microgram of emetine per ml and 20 micrograms of NaF per ml, resulted in visible plaques at 7 to 10 days postinfection. A single-step procedure involving overlay with medium containing 50 ng of dextran sulfate per ml also resulted in plaque formation within 8 days postinfection. These assays represent reproducible and inexpensive methods for evaluating the infectious titers of typhus group rickettsiae, cloning single plaque isolates, and testing the susceptibilities of rickettsiae to antibiotics. PMID:8818887

Policastro, P F; Peacock, M G; Hackstadt, T

1996-01-01

9

New World Hantaviruses Activate IFNlambda Production in Type I IFN-Deficient Vero E6 Cells  

Microsoft Academic Search

BackgroundHantaviruses indigenous to the New World are the etiologic agents of hantavirus cardiopulmonary syndrome (HCPS). These viruses induce a strong interferon-stimulated gene (ISG) response in human endothelial cells. African green monkey-derived Vero E6 cells are used to propagate hantaviruses as well as many other viruses. The utility of the Vero E6 cell line for virus production is thought to owe

Joseph Prescott; Pamela Hall; Mariana Acuna-Retamar; Chunyan Ye; Marc G. Wathelet; Hideki Ebihara; Heinz Feldmann; Brian Hjelle; Bradley S. Schneider

2010-01-01

10

Proteomic analysis of membrane proteins of vero cells: exploration of potential proteins responsible for virus entry.  

PubMed

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

Guo, Donghua; Zhu, Qinghe; Zhang, Hong; Sun, Dongbo

2014-01-01

11

Cytoprotective role of Solanum nigrum against gentamicin-induced kidney cell (Vero cells) damage in vitro  

Microsoft Academic Search

The 50% ethanol extract of the whole plant of Solanum nigrum was tested in vitro for its cytoprotection against gentamicin-induced toxicity on Vero cells. Cytotoxicity was significantly inhibited as assessed by the Trypan blue exclusion assay and mitochondrial dehydrogenase activity (MTT) assay. The test extract also exhibited significant hydroxyl radical scavenging potential, thus suggesting its probable mechanism of cytoprotection.

V. Prashanth Kumar; S. Shashidhara; M. M. Kumar; B. Y. Sridhara

2001-01-01

12

New World Hantaviruses Activate IFN? Production in Type I IFN-Deficient Vero E6 Cells  

PubMed Central

Background Hantaviruses indigenous to the New World are the etiologic agents of hantavirus cardiopulmonary syndrome (HCPS). These viruses induce a strong interferon-stimulated gene (ISG) response in human endothelial cells. African green monkey-derived Vero E6 cells are used to propagate hantaviruses as well as many other viruses. The utility of the Vero E6 cell line for virus production is thought to owe to their lack of genes encoding type I interferons (IFN), rendering them unable to mount an efficient innate immune response to virus infection. Interferon ?, a more recently characterized type III IFN, is transcriptionally controlled much like the type I IFNs, and activates the innate immune system in a similar manner. Methodology/Principal Findings We show that Vero E6 cells respond to hantavirus infection by secreting abundant IFN?. Three New World hantaviruses were similarly able to induce IFN? expression in this cell line. The IFN? contained within virus preparations generated with Vero E6 cells independently activates ISGs when used to infect several non-endothelial cell lines, whereas innate immune responses by endothelial cells are specifically due to viral infection. We show further that Sin Nombre virus replicates to high titer in human hepatoma cells (Huh7) without inducing ISGs. Conclusions/Significance Herein we report that Vero E6 cells respond to viral infection with a highly active antiviral response, including secretion of abundant IFN?. This cytokine is biologically active, and when contained within viral preparations and presented to human epithelioid cell lines, results in the robust activation of innate immune responses. We also show that both Huh7 and A549 cell lines do not respond to hantavirus infection, confirming that the cytoplasmic RNA helicase pathways possessed by these cells are not involved in hantavirus recognition. We demonstrate that Vero E6 actively respond to virus infection and inhibiting IFN? production in these cells might increase their utility for virus propagation. PMID:20567522

Prescott, Joseph; Hall, Pamela; Acuna-Retamar, Mariana; Ye, Chunyan; Wathelet, Marc G.; Ebihara, Hideki; Feldmann, Heinz; Hjelle, Brian

2010-01-01

13

Isolation and propagation of Dengue virus in Vero and BHK-21 cells expressing human DC-SIGN stably.  

PubMed

The "standard" methods of isolating dengue virus (DENV) utilize the mosquito cell line C6/36, monkey kidney LLC-MK2 cells, Vero cells, or baby hamster kidney (BHK-21) cells. However, these cells lines lack a particular DENV receptor, known as dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), which is expressed on immature dendritic cells and monocytes/macrophages. This may result in less efficient virus isolation and propagation. The present study used a lentivirus vector to establish Vero and BHK-21 cell lines (Vero-DC and BHK-DC) that express human DC-SIGN stably. Five DENV strains, each passaged several times in C6/36 cells, replicated more efficiently in Vero-DC and BHK-DC than in the parental Vero or BHK-21 cells. Vero/Vero-DC and BHK-21/BHK-DC were used to isolate virus from buffy coats and plasma samples derived from 13 patients infected with DENV. Most of the viruses showed increased production in cell lines expressing DC-SIGN. However, the isolation rate was lower (15.4-46.2%) than that from C6/36 cells (84.6%). Interestingly, when the viruses were isolated in C6/36 cells prior to infecting Vero/Vero-DC and BHK-21/BHK-DC, the rate of virus production increased markedly, reaching levels higher than those initially achieved in C6/36 cells. These data suggest that Vero-DC and BHK-DC could be useful tools for virus propagation, and that human specimens may contain a factor that interferes with virus growth in mammalian cells. PMID:25205264

Phanthanawiboon, Supranee; A-Nuegoonpipat, Atchareeya; Panngarm, Narawan; Limkittikul, Kriengsak; Ikuta, Kazuyoshi; Anantapreecha, Surapee; Kurosu, Takeshi

2014-12-01

14

Preflucel®: a Vero-cell culture-derived trivalent influenza vaccine.  

PubMed

Vaccination is the principal means to reduce the impact of influenza infection. Effective vaccination programs require a reliable and safe production system. Traditionally, influenza vaccines are produced in embryonated chicken eggs. Over the last two decades, new cell culture-derived vaccines have been licensed and manufactured, and other vaccines are still in various phases of development. Vero cells have been used for the development of a wide variety of vaccines including influenza vaccines. Pandemic and avian influenza vaccines derived from Vero cells have been shown to be well tolerated and immunogenic in animal and Phase I-II clinical studies. A Phase III randomized, double-blind, placebo-controlled trial of a trivalent influenza vaccine produced in Vero-cell culture was conducted in 7250 adults aged 18-49 years. Overall protective efficacy for antigenically matched influenza vaccine was 78.5%. The vaccine was well tolerated with no treatment-related serious adverse events and compared favorably with egg-derived vaccines from previous trials. Vero-cell-derived influenza vaccines have the potential to be an important parts of the influenza vaccine strategy, especially if an avian-derived strain becomes predominant or the demand outstrips the capacity of egg-based production systems. PMID:22913252

Chan, Candice Yuen-Yue; Tambyah, Paul Anantharajah

2012-07-01

15

Development of a mammalian cell (Vero) derived candidate influenza virus vaccine  

Microsoft Academic Search

Influenza vaccine production is dependent on the availability of embryonated hen eggs for virus growth. This is an extremely cumbersome system with many disadvantages with respect to selection of virus variants and presence of adventitious viruses. We have developed an alternative cell culture system which allows rapid production of large volumes of vaccine. The World Health Organisation (WHO) approved Vero

O Kistner; P. N. Barrett; W. Mundt; M. Reiter; S. Schober-Bendixen; F. Dorner

1998-01-01

16

An immunogenicity study of a newly introduced purified vero cell rabies vaccine ( Abhayrab) manufactured in India  

Microsoft Academic Search

Purified Vero cell culture rabies vaccine “Abhayrab” manufactured by Human Biologicals Institute, Ooty, India was subjected for immunogenicity studies. Pre-exposure study was undertaken on 60 healthy volunteers (Group I) with vaccination on days 0, 7 and 21. A group of 75 patients of category II (Group II), 67 of category III (Group III) were given post-exposure prophylaxis and 88 patients

G. Sampath; Suhasini V. Reddy; M. Lakshmi Prasad Rao; Y. Udayabhaskara Rao; C. Palaniappan

2005-01-01

17

Studies on the synthesis of betahCG hormone in vero cells by recombinant vaccinia virus.  

PubMed

Synthesis of the beta-subunit of human chorionic gonado-tropin (betahCG) in Vero cells by the recombinant vaccinia virus has been studied. The yield of betahCG was a function of the multiplicity of infection (MOI), and was highest at 25 MOI. The kinetics of synthesis and initial secretion of betahCG, deduced from the pulse-chase experiments were "zero order." At 30 h postinfection, the relative values of net synthesis and secretion rates were 4.0 AU. mm(2) betahCG/10(6) cells. h and 1.55 AU. mm(2) betahCG/10(6) cells. h, respectively. The time required to secrete 50% of intracellular betahCG was 210 min. Pulse-chase data also showed that 24% of betahCG was degraded intracelluiarly within 10 h, of which 17% was detected in the autoradiogram. Along with 30 kD betahCG, a satellite band of 28 kD was evident among the peptide synthesized in Vero cells. The molecular weight of vaccinia-derived betahCG was 13 kD more that its nonglycosylated form, indicating extensive glycosylation in Vero cells. The mRNA levels in infected Vero cells at different postinfection times were quantified by excess DNA dot-blot hybridization. It appears that the Vero cell possesses some host cell-associated factor(s), which prevented the transcription of early betahCG-mRNA promoted by the early signal of the vaccinia P 7.5 promoter. The half-life of betahCG-mRNA, as determined by follow-up of decay after blocking transcription initiation, was found to be 6.4 h. The synthesized betahCG was immunoreactive as it reacted with monoclonal and polyclonal monospecific antibodies. The subunit was also biologically active, as it combined with native betahCG to form heterodimer betahCG, which competed with (125)I-hCG for radioreceptors and stimulated testosterone synthesis in Leydig cells. (c) 1995 John Wiley & Sons, Inc. PMID:18623472

Mukhopadhyay, A; Mukhopadhyay, S N; Talwar, G P

1995-10-20

18

Changes in the Receptorbinding Haemagglutinin Protein of Wild-type Morbilliviruses are not Required for Adaptation to Vero Cells  

Microsoft Academic Search

We examined the consequences of isolation and adaptation to Vero cells for the receptorbinding haemagglutinin (H) gene of four syncytia-forming isolates of canine distemper virus (CDV) and of a dolphin morbillivirus isolate. A Vero-adapted CDV isolate exhibited biased hypermutation, since 11 out of 12 nucleotide differences to other isolates from the same epidemic were U–C transitions. Most of these transitions

Line Nielsen; Mads Klindt Andersen; Tove Dannemann Jensen; Merete Blixenkrone-Møller; Gert Bolt

2003-01-01

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

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

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

2014-01-01

20

Intracellular location of Mycoplasma genitalium in cultured Vero cells as demonstrated by electron microscopy.  

PubMed Central

The original two strains of Mycoplasma genitalium were isolated from the human urogenital tract. No other strains have been isolated from this site since then. We have recently succeeded in propagating a third strain from a urogenital specimen from a patient with urethritis in Vero cell cultures. By electron microscopy mycoplasmas were demonstrated intracellularly in about 10% of the examined Vero cells. Various stages of penetration into the cells could be observed. The flask-shaped organisms seemed to penetrate into the cells by the tip-end which included a rodlike structure. The intracellular location of normal mycoplasmas were in membrane-bound vacuoles very close to the nucleus, occasionally together with a few disintegrated organisms. In a few cells additional material was entangling the mycoplasmas in the cytoplasmic vacuoles. The potential for intracellular survival of M. genitalium may help the organism to evade the defence mechanisms of the human body. This trait may be considered a pathogenic property which supports the presumption that M. genitalium has clinical importance. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 1 Figure 2 Figure 7 Figure 8 PMID:8199010

Jensen, J. S.; Blom, J.; Lind, K.

1994-01-01

21

Isolation of Shiga toxin-resistant Vero cells and their use for easy identification of the toxin.  

PubMed Central

Shiga toxin-resistant Vero cells were isolated by treatment of the cells with nitrosoguanidine. These mutant cells were not affected by Shiga toxin at more than 1 microgram/ml, although the parent Vero cells were sensitive to 25 pg of the toxin per ml. Immunofluorescence studies showed that all the mutant cells had lost toxin-binding capacity. The cytotoxic activities of various bacterial cultures against the parent and mutant cells were compared. All samples from 10 strains of Shigella dysenteriae type 1 and all three strains of Escherichia coli O157:H7 tested showed cytotoxicity to the parent cells but not to the mutant cells. Samples from other organisms, such as Shigella flexneri, Shigella sonnei, Clostridium difficile, Aeromonas hydrophila, Aeromonas sobria, and other E. coli strains, either had no effect or were cytotoxic on both the parent and mutant cells. Thus, these mutant cells could be used to identify Shiga-like toxin and distinguish it from other cytotoxins. The results also suggest the presence of a receptor for Shiga-like toxin on Vero cells that is essential for expression of the cytotoxicity of Shiga toxin but is not essential for growth of Vero cells. PMID:3045003

Kongmuang, U; Honda, T; Miwatani, T

1988-01-01

22

Clathrin- and serine proteases-dependent uptake of porcine epidemic diarrhea virus into Vero cells.  

PubMed

Porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus, is a causative agent of porcine enteric disease characterized by acute watery diarrhea and dehydration in sucking piglet. Similar to other coronaviruses, PEDV spike protein mediates its cell entry by binding to cellular receptors and inducing membrane fusion between viral envelopes and cellular membranes. However, the entry mechanism of PEDV is not studied. Here, we determined the entry mechanism of PEDV into Vero cells. Our data confirmed that PEDV entry followed clathrin-mediated endocytosis independence of caveolae-coated pit assembly. The internalized PEDV was co-localized with the clathrin-mediated endocytic marker, but not with the caveolae-mediated endocytic marker. In addition, cells treated with lysosomotropic agents and serine protease inhibitors were resistant to PEDV. Our data revealed that PEDV entry followed clathrin-mediated endocytosis and was dependent on a low pH and serine proteolysis for successful entry into cells. PMID:25086180

Park, Jung-Eun; Cruz, Deu John M; Shin, Hyun-Jin

2014-10-13

23

Cytotoxicity of methanol extracts of Elaeis guineensis on MCF-7 and Vero cell lines  

PubMed Central

Objective To investigate the cytotoxic effect of Elaeis guineensis methanol extract on MCF-7 and Vero cell. Methods In vitro cytotoxicity was evaluated in by MTT assay. Cell morphological changes were observed by using light microscope. Results The MTT assay indicated that methanol extract of the plant exhibited significant cytotoxic effects on MCF-7. Morphological alteration of the cell lines after exposure with Elaeis guineensis extract were observed under phase contrast microscope in the dose dependent manner. Conclusions The results suggest the probable use of the Elaeis guineensis methanol extract in preparing recipes for cancer-related ailments. Further studies on isolation of metabolites and their in vivo cytotoxicity are under investigation. PMID:23569855

Vijayarathna, Soundararajan; Sasidharan, Sreenivasan

2012-01-01

24

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

PubMed

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

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

2011-07-01

25

An immunogenicity study of a newly introduced purified Vero cell rabies vaccine (Abhayrab) manufactured in India.  

PubMed

Purified Vero cell culture rabies vaccine "Abhayrab" manufactured by Human Biologicals Institute, Ooty, India was subjected for immunogenicity studies. Pre-exposure study was undertaken on 60 healthy volunteers (Group I) with vaccination on days 0, 7 and 21. A group of 75 patients of category II (Group II), 67 of category III (Group III) were given post-exposure prophylaxis and 88 patients of category III were administered with rabies immunoglobulins (Group IV) along with post-exposure prophylaxis as per World Health Organization (WHO) recommendations with a booster on day 90. The volunteers and patients vaccinated showed very few adverse side effects. The blood samples collected from volunteers (Group I) on days 14, 35 and 365 and patients (Group II-IV) on days 14, 30, 90 and 365 showed geometric mean titres (GMT) of >0.5 IU/ml. The study indicated new rabies vaccine manufactured in India was found to be safe and immunogenic. PMID:15603890

Sampath, G; Reddy, Suhasini V; Rao, M Lakshmi Prasad; Rao, Y Udayabhaskara; Palaniappan, C

2005-01-01

26

Porous poly( l-lactide) films obtained by immersion precipitation process: morphology, phase separation and culture of VERO cells  

Microsoft Academic Search

In this work, the immersion precipitation process was used to obtain porous poly(l-lactide) films which were tested as supports for culture of VERO cells. The mechanism of phase separation taking place during the film formation was investigated using light scattering measurements. A theoretical ternary phase diagram was proposed and correlated with the light scattering results. The film morphology was investigated

R. A Zoppi; S Contant; E. A. R Duek; F. R Marques; M. L. F Wada; S. P Nunes

1999-01-01

27

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

28

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

PubMed Central

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

Vilchez Larrea, Salome C.; Kun, Alejandra

2014-01-01

29

Comparison of use of Vero cell line and suspension culture of murine macrophage to attenuation of virulence of Neospora caninum.  

PubMed

In this study the tachyzoite yields of Neospora caninum were compared in two cell lines: Vero (African Green Monkey Kidney) and suspension culture of murine macrophage (J774) cell lines. Then, N. caninum were continuously passaged in these cell lines for 3 months and the effect of host cells on virulence of tachyzoites was assessed by broiler chicken embryonated eggs. Inoculation was performed in the chorioallantoic (CA) liquid of the embryonated eggs with different dilutions (0.5 × 10(4), 1.0 × 10(4), 1.5 × 10(4)) of tachtzoites isolated from these cell cultures. The mortality pattern and pathological changes of the dead embryos and hatched chickens were noted. Tissue samples of brain, liver and heart were examined by histopathological and detection of DNA of parasite by polymerase chain reaction (PCR). Also, consecutive sections of the tissues examined histologically were used for immunohistochemical (IHC) examination. Embryos inoculated with tachyzoites derived from Vero cell line (group V) showed a higher mortality rate (100%) than the embryos that received tachyzoites derived from J774 cell line (group J) (10% mortality rate). The results of this study indicated that the culture of N. caninum in J774 cell led to a marked increase in the number of tachyzoite yields and rapid attenuation in comparison to Vero, so the results were confirmed by IHC and PCR. This study is the first report of the significant effect of host cell on the attenuation of virulence of N. caninum tachyzoites. These findings could potentially provide a practical approach in the mass production of N. caninum tachyzoites, and also in producing live attenuated vaccine. PMID:23684321

Khordadmehr, Monireh; Namavari, Mehdi; Khodakaram-Tafti, Azizollah; Mansourian, Maryam; Rahimian, Abdollah; Daneshbod, Yahya

2013-10-01

30

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

PubMed Central

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

Kistner, Otfried; Howard, Keith; Spruth, Martin; Wodal, Walter; Bruhl, 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

31

Phorbol Esters Isolated from Jatropha Meal Induced Apoptosis-Mediated Inhibition in Proliferation of Chang and Vero Cell Lines  

PubMed Central

The direct feeding of Jatropha meal containing phorbol esters (PEs) indicated mild to severe toxicity symptoms in various organs of different animals. However, limited information is available on cellular and molecular mechanism of toxicity caused by PEs present in Jatropha meal. Thus, the present study was conducted to determine the cytotoxic and mode of action of PEs isolated from Jatropha meal using human hepatocyte (Chang) and African green monkey kidney (Vero) cell lines. The results showed that isolated PEs inhibited cell proliferation in a dose-dependent manner in both cell lines with the CC50 of 125.9 and 110.3 ?g/mL, respectively. These values were compatible to that of phorbol 12-myristate 13-acetate (PMA) values as positive control i.e., 124.5 and 106.3 ?g/mL respectively. Microscopic examination, flow cytometry and DNA fragmentation results confirmed cell death due to apoptosis upon treatment with PEs and PMA at CC50 concentration for 24 h in both cell lines. The Western blot analysis revealed the overexpression of PKC-? and activation of caspase-3 proteins which could be involved in the mechanism of action of PEs and PMA. Consequently, the PEs isolated form Jatropha meal caused toxicity and induced apoptosis-mediated proliferation inhibition toward Chang and Vero cell lines involving over-expression of PKC-? and caspase-3 as their mode of actions. PMID:23203036

Oskoueian, Ehsan; Abdullah, Norhani; Ahmad, Syahida

2012-01-01

32

Preclinical evaluation of Vaxfectin®-adjuvanted Vero cell-derived seasonal split and pandemic whole virus influenza vaccines  

PubMed Central

Increasing the potency and supply of seasonal and pandemic influenza vaccines remains an important unmet medical need which may be effectively accomplished with adjuvanted egg- or cell culture-derived vaccines. Vaxfectin®, a cationic lipid-based adjuvant with a favorable safety profile in phase 1 plasmid DNA vaccines trials, was tested in combination with seasonal split, trivalent and pandemic whole virus, monovalent influenza vaccines produced in Vero cell cultures. Comparison of hemagglutination inhibition (HI) antibody titers in Vaxfectin®-adjuvanted to nonadjuvanted vaccinated mice and guinea pigs revealed 3- to 20-fold increases in antibody titers against each of the trivalent influenza virus vaccine strains and 2- to 8-fold increases in antibody titers against the monovalent H5N1 influenza virus vaccine strain. With the vaccine doses tested, comparable antibody responses were induced with formulations that were freshly prepared or refrigerated at conventional 2–8°C storage conditions for up to 6 mo. Comparison of T-cell frequencies measured by interferon-gamma ELISPOT assay between groups revealed increases of between 2- to 10-fold for each of the adjuvanted trivalent strains and up to 22-fold higher with monovalent H5N1 strain. Both trivalent and monovalent vaccines were easy to formulate with Vaxfectin® by simple mixing. These preclinical data support further testing of Vaxfectin®-adjuvanted Vero cell culture vaccines toward clinical studies designed to assess safety and immunogenicity of these vaccines in humans. PMID:23857272

Smith, Larry R.; Wodal, Walter; Crowe, Brian A.; Kerschbaum, Astrid; Bruehl, Peter; Schwendinger, Michael G.; Savidis-Dacho, Helga; Sullivan, Sean M.; Shlapobersky, Mark; Hartikka, Jukka; Rolland, Alain; Barrett, P. Noel; Kistner, Otfried

2013-01-01

33

Induction of apoptosis in Vero cells by Newcastle disease virus requires viral replication, de-novo protein synthesis and caspase activation  

Microsoft Academic Search

Newcastle disease virus causes (NDV) apoptotic death of infected cells. In the present study, the stimulus that provoked the induction of apoptosis in infected cells was examined. Vero cells infected with NDV developed apoptosis as characterized by DNA fragmentation and decreased DNA content. In presence of ammonium chloride, infected cells did not show reduced DNA content indicating the requirement of

P. V. Ravindra; Ashok K. Tiwari; Barkha Ratta; Uttara Chaturvedi; Sudesh Kumar Palia; Prasant Kumar Subudhi; Rajiv Kumar; Bhaskar Sharma; Anant Rai; R. S. Chauhan

2008-01-01

34

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

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

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

2014-01-01

35

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

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

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

2014-01-01

36

[Vitaherpavac is the first Russian herpes simplex virus vaccine obtained on the Vero B continuous cell line].  

PubMed

Vitaherpavac, a dry inactivated herpes simplex virus (HSV) culture vaccine, has been obtained, by using the Vero B continuous cell line as a substrate for accumulation of herpes simplex virus types 1 (US strain) and 2 (VN strain). Vitaherpavac and the similar vaccine Herpovax made by the Research Institute of Vaccines and Sera, Saint Petersburg (for which preparation a primary trypsinized chick embryo cell culture used as a substrate for accumulation of HSV types 1 and 2), underwent comparative clinical trials. The tolerability and therapeutic effectiveness of the vaccine were tested in patients diagnosed as having chronic frequently recurring herpes. The trials have yielded positive results that suggest that it is expedient to introduce of the new vaccine Vitaherpavac into practice to treat chronic recurrent herpetic infection of various localizations. Vitaherpavac has been registered in the Russian Federation and permitted for medical application. PMID:19882901

Barkhaleva, O A; Ladyzhenskaia, I P; Vorob'eva, M S; Shalunova, N V; Podcherniaeva, R Ia; Mikha?lova, G R; Khorosheva, T V; Barinski?, I F

2009-01-01

37

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

PubMed

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 B? (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

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

2013-08-01

38

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

PubMed Central

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

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

2013-01-01

39

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

SciTech Connect

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.

Zhou, Fangye; Zhou, Jian; Ma, Lei; Song, Shaohui; Zhang, Xinwen; Li, Weidong; Jiang, Shude [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People's Republic of China (China)] [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People's Republic of China (China); Wang, Yue, E-mail: euy-tokyo@umin.ac.jp [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Yingxin Lane 100, Xicheng District, Beijing 100052, People's Republic of China (China)] [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Yingxin Lane 100, Xicheng District, Beijing 100052, People's Republic of China (China); Liao, Guoyang, E-mail: liaogy@21cn.com [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People's Republic of China (China)] [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People's Republic of China (China)

2012-05-18

40

Induction of apoptosis in Vero cells by Newcastle disease virus requires viral replication, de-novo protein synthesis and caspase activation.  

PubMed

Newcastle disease virus causes (NDV) apoptotic death of infected cells. In the present study, the stimulus that provoked the induction of apoptosis in infected cells was examined. Vero cells infected with NDV developed apoptosis as characterized by DNA fragmentation and decreased DNA content. In presence of ammonium chloride, infected cells did not show reduced DNA content indicating the requirement of virus entry for the induction of apoptosis. UV-inactivated NDV did not induce apoptosis in cells suggesting the need of virus replication. Although cycloheximide blocked NDV-induced apoptosis, actinomycin-D did not, suggesting that de-novo viral protein synthesis was critical for the induction of apoptosis. In addition, activation of caspases was also detected by flowcytometry, indirect fluorescent and colorimetric assays. Based on the results, it was concluded that NDV-induced apoptosis in Vero cells required virus replication, de-novo protein synthesis and caspase activation. PMID:18329746

Ravindra, P V; Tiwari, Ashok K; Ratta, Barkha; Chaturvedi, Uttara; Palia, Sudesh Kumar; Subudhi, Prasant Kumar; Kumar, Rajiv; Sharma, Bhaskar; Rai, Anant; Chauhan, R S

2008-05-01

41

Autophagic Cell Death Is Induced by Acetone and Ethyl Acetate Extracts from Eupatorium odoratum In Vitro: Effects on MCF-7 and Vero Cell Lines  

PubMed Central

Eupatorium odoratum (EO) contains many biologically active compounds, the anticancer effects of which are not well documented. This study evaluates the cytotoxic effects and mechanism of action of EO extracts on MCF-7 and Vero cell lines. Evaluation of the cytotoxic activity using MTT assay, morphological alterations, and apoptosis were carried out. Autophagy was evaluated by LC3-A protein expression. Cytotoxic activity, membrane blebbing and ballooning at 24 hours, replacement by mass vacuolation, and double membrane vesicles mimicking autophagy and cell death were observed in the cancer cells. No apoptosis was observed by DNA fragmentation assay. Overexpression of LC3-A protein indicated autophagic cell death. Cell cycle analysis showed G0 and G2/M arrest. The Vero cells did not show significant cell death at concentrations <100??g/mL. These results thus suggest that acetone and ethyl acetate extracts of EO induce cell death through induction of autophagy and hold potential for development as potential anticancer drugs. PMID:22666123

Harun, Faizah Bt.; Syed Sahil Jamalullail, Syed Mohsin; Yin, Khoo Boon; Othman, Zulkhairi; Tilwari, Anita; Balaram, Prabha

2012-01-01

42

Essential Role for Verotoxin in Sustained Stress-Activated Protein Kinase and Nuclear Factor Kappa B Signaling, Stimulated by Escherichia coli O157:H7 in Vero Cells  

Microsoft Academic Search

The effects of Escherichia coli O157:H7 (strains E30480 and PM601) and the associated verotoxins (VTs), VT1 and VT2, on stress-activated protein kinase and nuclear factor kappa B (NF-B) signaling were investi- gated with Vero cells, which are extremely sensitive to the cytotoxic effects of E. coli O157:H7 in vitro. Cell-free supernatants prepared from E30480 and PM601 cultures and purified VT1

Pamela Cameron; Deborah Bingham; Andrew Paul; Martin Pavelka; Scott Cameron; Dino Rotondo; Robin Plevin

2002-01-01

43

Vero cells injected with adenovirus type 2 mRNA produce authentic viral polypeptide patterns: early mRNA promotes growth of adenovirus-associated virus.  

PubMed Central

Adenovirus type 2 mRNAs were injected via glass capillaries into Vero cells, a line of African green monkey kidney cells permissive for adenovirus growth. Polypeptides synthesized after injection were labeled with 35S-labeled amino acids, precipitated with antiviral sera, and analyzed by polyacrylamide gel electrophoresis. Both early and late viral mRNAs give rise to authentic polypeptides. The in vivo translation of mRNAs can be measured as late as 24 hr after injection. The ability to analyze the protein products of microinjected mRNAs directly should greatly extend the applications of the procedure. Vero cells injected with early mRNA from adenovirus type 2 support the growth of adenovirus-associated virus, a defective virus that is dependent on adenovirus helper functions. This result demonstrates that a measurable biological activity, the ability to overcome the defectiveness of adenovirus-associated virus, resides in early adenovirus mRNA. Images PMID:6928688

Richardson, W D; Carter, B J; Westphal, H

1980-01-01

44

Apoptosis induction in BEFV-infected Vero and MDBK cells through Src-dependent JNK activation regulates caspase-3 and mitochondria pathways  

PubMed Central

Our previous report demonstrated that bovine ephemeral fever virus (BEFV)-infected cultured cells could induce caspase-dependent apoptosis. This study aims to further elucidate how BEFV activates the caspase cascade in bovine cells. BEFV replicated and induced apoptosis in Vero and Madin-Darby bovine kidney (MDBK) cells, and a kinetic study showed a higher efficiency of replication and a greater apoptosis induction ability of BEFV in Vero cells. Src and c-Jun N-terminal kinase (JNK) inhibitor, but not extracellular signal-regulated kinase (ERK) or p38 inhibitor, alleviated BEFV-mediated cytopathic effect and apoptosis. In BEFV-infected Vero and MDBK cells, BEFV directly induced Src tyrosine-418 phosphorylation and JNK phosphorylation and kinase activity, which was inhibited specifically by SU6656 and SP600125, respectively. The caspase cascade and its downstream effectors, Poly (ADP-ribose) polymerase (PARP) and DFF45, were also activated simultaneously upon BEFV infection. In addition, cytochrome c, but not Smac/DIABLO, was released gradually from mitochondria after BEFV infection. SU6656 suppressed Src, JNK, and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage; SP600125 reduced JNK and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage. Taken together, these results strongly support the hypothesis that a Src-dependent JNK signaling pathway plays a key role in BEFV-induced apoptosis. The molecular mechanism identified in our study may provide useful information for the treatment of BEFV. PMID:19846041

Chen, Chun-Yen; Chang, Chin-Yang; Liu, Hung-Jen; Liao, Ming-Huei; Chang, Chi-I; Hsu, Jue-Liang; Shih, Wen-Ling

2009-01-01

45

Apoptosis induction in BEFV-infected Vero and MDBK cells through Src-dependent JNK activation regulates caspase-3 and mitochondria pathways.  

PubMed

Our previous report demonstrated that bovine ephemeral fever virus (BEFV)-infected cultured cells could induce caspase-dependent apoptosis. This study aims to further elucidate how BEFV activates the caspase cascade in bovine cells. BEFV replicated and induced apoptosis in Vero and Madin-Darby bovine kidney (MDBK) cells, and a kinetic study showed a higher efficiency of replication and a greater apoptosis induction ability of BEFV in Vero cells. Src and c-Jun N-terminal kinase (JNK) inhibitor, but not extracellular signal-regulated kinase (ERK) or p38 inhibitor, alleviated BEFV-mediated cytopathic effect and apoptosis. In BEFV-infected Vero and MDBK cells, BEFV directly induced Src tyrosine-418 phosphorylation and JNK phosphorylation and kinase activity, which was inhibited specifically by SU6656 and SP600125, respectively. The caspase cascade and its downstream effectors, Poly (ADP-ribose) polymerase (PARP) and DFF45, were also activated simultaneously upon BEFV infection. In addition, cytochrome c, but not Smac/DIABLO, was released gradually from mitochondria after BEFV infection. SU6656 suppressed Src, JNK, and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage; SP600125 reduced JNK and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage. Taken together, these results strongly support the hypothesis that a Src-dependent JNK signaling pathway plays a key role in BEFV-induced apoptosis. The molecular mechanism identified in our study may provide useful information for the treatment of BEFV. PMID:19846041

Chen, Chun-Yen; Chang, Chin-Yang; Liu, Hung-Jen; Liao, Ming-Huei; Chang, Chi-I; Hsu, Jue-Liang; Shih, Wen-Ling

2010-01-01

46

Bovine colostrum ultrafiltrate supplemented with adult bovine serum and transferrin: An effective fbs substitute for cultivation of vero and CHO-K1 cells  

Microsoft Academic Search

Summary  A mixture containing an ultrafiltrate fraction (UF) of bovine colostrum (6.7%), adult bovine serum (BS) (1%), and human holo-transferrin\\u000a (hTF) (5 mg\\/liter) was developed for cultivation of Chinese hamster ovary cells (CHO-K1) and African green monkey kidney cells\\u000a (Vero). The growth-supporting activity of the mixture (UF\\/BS\\/hTF) was comparable to that of 1 to 10% fetal bovine serum (FBS)\\u000a and considerably

Raimo Pakkanen

1994-01-01

47

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

SciTech Connect

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.

Yeung, Y.-S. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: ysyeung@graduate.hku.hk; Yip, C.-W. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: h0024004@hkusua.hku.hk; Hon, C.-C. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: h9826299@hkusua.hku.hk; Chow, Ken Y.C. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: chow@pasteur.fr; Ma, Iris C.M. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: h0105962@hkusua.hku.hk; Zeng Fanya [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: fzeng@hkucc.hku.hk; Leung, Frederick C.C. [Department of Zoology, Kadoorie Biological Science Building, University of Hong Kong, Hong Kong (China)], E-mail: fcleung@hkucc.hku.hk

2008-02-05

48

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

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

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

2013-01-01

49

Comparison of procedures for the extraction of supernatants and cytotoxicity tests in Vero cells, applied to assess the toxigenic potential of Bacillus spp. and Lactobacillus spp., intended for use as probiotic strains.  

PubMed

Interest in using Bacillus strains as probiotic components of animal feeds has grown in recent years. However, some of these strains, especially those taxonomically related to the Bacillus cereus group, may have enterotoxigenic activity. Assessment of their toxigenic potential by well-established and robust protocols is required before authorizing their use in animal nutrition. Three methods of extraction and concentration of supernatants of Bacillus and Lactobacillus strains (methanol extraction, ammonium sulphate and ultrafiltration concentration) and three cytotoxic tests in Vero cells (WST-1, LDH and protein synthesis inhibition assays) for the assessment of the cytotoxicity activity of Lactobacillus strains (as probiotic strains in human and animal nutrition) and Bacillus toyonensis BCT-7112(T) (as animal probiotic strain in animal nutrition-Toyocerin®-) were evaluated in this study. Methanol extraction was not useful under any circumstances. The other two concentration methods (ammonium sulphate and ultrafiltration) were feasible, with slightly greater sensitivity achieved by ultrafiltration. The probiotic strain B. toyonensis BCT-7112(T) proved to be a non-cytotoxic strain in all the protocols tested. However, some Lactobacillus strains showed cytotoxicity activity, regardless of the protocols applied. PMID:24938520

Blanch, Anicet R; Méndez, Javier; Castel, Susana; Reina, Manuel

2014-08-01

50

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

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

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

2000-01-01

51

Transport of an external Lys-Asp-Glu-Leu (KDEL) protein from the plasma membrane to the endoplasmic reticulum: studies with cholera toxin in Vero cells  

PubMed Central

The A2 chain of cholera toxin (CTX) contains a COOH-terminal Lys-Asp- Glu-Leu (KDEL) sequence. We have, therefore, analyzed by immunofluorescence and by subcellular fractionation in Vero cells whether CTX can used to demonstrate a retrograde transport of KDEL proteins from the Golgi to the ER. Immunofluorescence studies reveal that after a pulse treatment with CTX, the CTX-A and B subunits (CTX-A and CTX-B) reach Golgi-like structures after 15-20 min (maximum after 30 min). Between 30 and 90 min, CTX-A (but not CTX-B) appear in the intermediate compartment and in the ER, whereas the CTX-B are translocated to the lysosomes. Subcellular fractionation studies confirm these results: after CTX uptake for 15 min, CTX-A is associated only with endosomal and Golgi compartments. After 30 min, a small amount of CTX-A appears in the ER in a trypsin-resistant form, and after 60 min, a significant amount appears. CTX-A seems to be transported mainly in its oxidized form (CTX-A1-S-S-CTX-A2) from the Golgi to the ER, where it becomes slowly reduced to form free CTX A1 and CTX-A2, as indicated by experiments in which cells were homogenized 30 and 90 min after the onset of CTX uptake in the presence of N- ethylmaleimide. Nocodazol applied after accumulation of CTX in Golgi inhibits the appearance of CTX-A in the ER and delays the increase of 3',5'cAMP, indicating the participation of microtubules in the retrograde Golgi-ER transport. PMID:8666663

1996-01-01

52

Cytopathic effect, plaque formation, and lysis of Ehrlichia chaffeensis grown on continuous cell lines.  

PubMed Central

Ehrlichiae are strict intracellular bacterial pathogens that parasitize leukocytes or other blood cells. Only six agents of the tribe Ehrlichieae, namely, Cowdria ruminantium, Neorickettsia helminthoeca, Ehrlichia risticii, Ehrlichia sennetsu, Ehrlichia canis, and Ehrlichia chaffeensis, have been adapted to growth in continuous cell lines. E. chaffeensis, the agent of human ehrlichiosis, has been cultured only in a cell line of canine origin. We adapted purified cell-free E. chaffeensis for growth in human embryonic lung (HEL) fibroblasts (HEL 299), green monkey kidney cells (Vero), and a human cervical epithelioid carcinoma (HeLa) cell line. We observed a cytopathic effect with both Vero cells and HEL cells and plaque formation with cellular lysis when infected Vero cells were cultured in agar. Human fibroblasts are already commonly used for the isolation of viruses, coexiellae, and rickettsiae. Furthermore, the capability of these cells to support the growth of ehrlichiae suggests that they may be useful for primary isolation of ehrlichiae as well. The cytopathic effect produced in Vero or HEL cells offers a very helpful indicator of the infection. Plaque formation in Vero cells is a new phenomenon not yet reported for ehrlichiae and will allow the titration of inocula and clonal purification of this bacterium. Images PMID:8300201

Brouqui, P; Birg, M L; Raoult, D

1994-01-01

53

Process standardization for optimal virus recovery and removal of substrate DNA and bovine serum proteins in Vero cell-derived rabies vaccine.  

PubMed

Purification of a rabies vaccine by a single zonal centrifugation run was replaced by two runs with optimal standardization of the sucrose density gradient. As a result, significant reductions in the levels of substrate DNA and bovine serum protein in the Vero cell-derived human rabies vaccine were achieved. Following many trials, for the first run, loading of the 3.2-l capacity K-3 rotor with 1800 ml of 60% sucrose solution and 1400 ml of vaccine PBS buffer solution gave a satisfactory linear gradient. However, after the first run, the substrate DNA and bovine serum contents exceeded the required levels. After protamine sulphate and Tween-80 treatment of the concentrated inactivated material, a second run using the same procedure as in the first run was tried. However, these purification procedures resulted in low virus recovery. To achieve optimal virus recovery, and removal of substrate DNA and bovine serum protein, the peak fractions from the first run as indicated by the haemagglutination, sucrose concentration, and optical density values were pooled and the sucrose concentration of the pooled fractions was increased to 60%. A second (flotation) run was then carried out. Using this method, the virus recovery rate was more than 95% that of the first run, and the levels of cellular DNA and bovine serum protein were well within the acceptable limits of less than 100 pg/dose and one part per million, respectively. The substrate DNA was quantified by both radioactive labeling and non-radioactive biotin labeling methods. For the quantification of calf serum protein, a counter-immunoelectrophoresis method was developed and effectively applied. A potency assay was performed using the National Institutes of Health (NIH) and well-standardized in vitro single radial immuno diffusion (SRD) methods. Finally, an immunogenicity study was conducted with human volunteers and the results were confirmed by a rapid fluorescent focus inhibition test (RFFIT). PMID:16233321

Kumar, Ananda Arone Prem; Rao, Yarlagadda Udaya Bhaskara; Joseph, Arokiaswami Leo William; Mani, Kavaratty Raju; Swaminathan, Krishnaswami

2002-01-01

54

Colon tumor cells grown in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

55

A Single Dose of Vero Cell-Derived Japanese Encephalitis (JE) Vaccine (Ixiaro) Effectively Boosts Immunity in Travelers Primed With Mouse Brain-Derived JE Vaccines  

PubMed Central

Background.?A significant part of the world population lives in areas with endemic Japanese encephalitis (JE). For travelers from nonendemic countries, Vero cell–derived vaccine (JE-VC; Ixiaro) has replaced traditional mouse brain–derived vaccines (JE-MB) associated with safety concerns. The 2 vaccines are derived from different viral strains: JE-VC from the SA14-14-2 strain and JE-MB from the Nakayama strain. No data exist regarding whether JE-VC can be used to boost immunity after a primary series of JE-MB; therefore, a primary series of JE-VC has been recommended to all travelers regardless of previous vaccination history. Methods.?One hundred twenty travelers were divided into 4 groups: Volunteers with no prior JE vaccination received primary immunization with (group 1) JE-MB or (group 2) JE-VC, and those primed with JE-MB received a single booster dose of (group 3) JE-MB or (group 4) JE-VC. Immune responses were tested before and 4–8 weeks after vaccination using plaque reduction neutralization test (PRNT) against both vaccine strains. Results.?In vaccine-naive travelers, the vaccination response rate for test strains Nakayama and SA14-14-2 was 100% and 87% after primary vaccination with JE-MB and 87% and 94% after JE-VC, respectively. Antibody levels depended on the target virus, with higher titers against homologous than heterologous PRNT50 target strain (P < .001). In travelers primed with JE-MB, vaccination response rates were 91% and 91%, and 98% and 95% after a booster dose of JE-MB or JE-VC, respectively. Subgroup analysis revealed that a higher proportion of primed (98%/95%) than nonprimed (39%/42%) volunteers responded to a single dose of JE-VC (P < .001). Conclusions.?A single dose of JE-VC effectively boosted immunity in JE-MB–primed travelers. Current recommendations should be reevaluated. Clinical Trials Registration.?NCT01386827. PMID:22696017

Erra, Elina O.; Askling, Helena Hervius; Rombo, Lars; Riutta, Jukka; Vene, Sirkka; Yoksan, Sutee; Lindquist, Lars; Pakkanen, Sari H.; Huhtamo, Eili; Vapalahti, Olli; Kantele, Anu

2012-01-01

56

Quantitative Proteomics Using Stable Isotope Labeling with Amino Acids in Cell Culture Reveals Changes in the Cytoplasmic, Nuclear, and Nucleolar Proteomes in Vero Cells Infected with the Coronavirus Infectious Bronchitis Virus*  

PubMed Central

Virus-host interactions involve complex interplay between viral and host factors, rendering them an ideal target for proteomic analysis. Here we detail a high throughput quantitative proteomics analysis of Vero cells infected with the coronavirus infectious bronchitis virus (IBV), a positive strand RNA virus that replicates in the cytoplasm. Stable isotope labeling with amino acids in cell culture (SILAC) was used in conjunction with LC-MS/MS to identify and quantify 1830 cellular and two viral proteins from IBV-infected cells. Fractionation of cells into cytoplasmic, nuclear, and nucleolar extracts was used to reduce sample complexity and provide information on the trafficking of proteins between the different compartments. Each fraction showed a proportion of proteins exhibiting ?2-fold changes in abundance. Ingenuity Pathway Analysis revealed that proteins that changed in response to infection could be grouped into different functional categories. These included proteins regulated by NF-?B- and AP-1-dependent pathways and proteins involved in the cytoskeleton and molecular motors. A luciferase-based reporter gene assay was used to validate the up-regulation of AP-1- and NF-?B-dependent transcription in IBV-infected cells and confirmed using immunofluorescence. Immunofluorescence was used to validate changes in the subcellular localization of vimentin and myosin VI in IBV-infected cells. The proteomics analysis also confirmed the presence of the viral nucleocapsid protein as localizing in the cytoplasm, nucleus, and nucleolus and the viral membrane protein in the cytoplasmic fraction. This research is the first application of SILAC to study total host cell proteome changes in response to positive sense RNA virus infection and illustrates the versatility of this technique as applied to infectious disease research. PMID:20467043

Emmott, Edward; Rodgers, Mark A.; Macdonald, Andrew; McCrory, Sarah; Ajuh, Paul; Hiscox, Julian A.

2010-01-01

57

A comparative study on the safety and immunogenicity of Purified duck embryo vaccine [corrected] (PDEV, Vaxirab) with purified chick embryo cell vaccine (PCEC, Rabipur) and purifed vero cell rabies vaccine (PVRV, Verorab).  

PubMed

Rabies is a fatal but preventable disease. Cell culture vaccines (CCV) and purified duck embryo vaccines (PDEV) are currently recommended by WHO for post-exposure prophylaxis. In India, a PDEV (Vaxirab) is being manufactured and is in use since 2003. In the present study, we have evaluated the safety, immunogenicity and tolerance of this vaccine with two other WHO approved CCVs, viz., purified chick embryo cell vaccine (PCEC, Rabipur) and purified vero cell rabies vaccine (PVRV, Veroroab). This study was an open label, randomized phase IV comparative clinical trial. A total of 152 people bitten by dogs and other animals were recruited from 4 different centres from India. They were randomly assigned to receive one of the vaccines by Essen intramuscular regimen (52 subjects received Vaxirab and 50 each Rabipur and Verorab) and rabies immunoglobulin was also administered in all category III exposures. Their blood samples were collected on day 0 (prior to vaccination), 14, 28, 90 and 180. Side effects if any were monitored. The rabies neutralizing antibody titers in their blood samples were estimated by the rapid fluorescent focus inhibition test (RFFIT). Subjects in all three groups had neutralizing antibody titers by day 14 (>0.5 IU/mL) and geometric mean titers (GMT) observed for different vaccines on all days tested did not vary significantly (p>0.5). Side effects observed were minimal and did not vary significantly among the groups. The results of the present study indicate that PDEV (Vaxirab) is as safe, tolerable and immunogenic as both PCEC (Rabipur) and PVRV (Verorab). Thus this vaccine can be a good alternative to WHO approved CCVs for rabies post-exposure prophylaxis. PMID:19818720

Ashwathnarayana, Doddabele Hanumantaiah; Madhusudana, Shampur Narayana; Sampath, Gadey; Sathpathy, Durga Madhab; Mankeshwar, Ranjit; Ravish, Haradana Halli Shankariah; Ullas, Padinjaremattathil Thankappan; Behra, Tapas Ranjan; Sudarshan, Mysore Kalappa; Gangaboraiah; Shamanna, Manjula

2009-12-10

58

Genetic Basis of Attenuation of Dengue Virus Type 4 Small Plaque Mutants with Restricted Replication in Suckling Mice and in SCID Mice Transplanted with Human Liver Cells  

Microsoft Academic Search

Mutations that restrict replication of dengue virus have been sought for the generation of recombinant live-attenuated dengue virus vaccines. Dengue virus type 4 (DEN4) was previously grown in Vero cells in the presence of 5-fluorouracil, and the characterization of 1248 mutagenized, Vero cell passaged clones identified 20 temperature-sensitive (ts) mutant viruses that were attenuated (att) in suckling mouse brain (J.

Joseph E. Blaney; Daniel H. Johnson; Gracielle G. Manipon; Cai-Yen Firestone; Christopher T. Hanson; Brian R. Murphy; Stephen S. Whitehead

2002-01-01

59

Outbreak of Human Metapneumovirus Detected by Use of the Vero E6 Cell Line in Isolates Collected in Yamagata, Japan, in 2004 and 2005  

Microsoft Academic Search

A number of epidemiological studies have shown human metapneumovirus (hMPV) to be one of the most important viral agents associated with acute respiratory infections in humans. However, due to the difficulty in growing the virus, all epidemiological studies of hMPV infection have been performed on the basis of the molecular method. Thus, the development of a cell line suitable for

C. Abiko; K. Mizuta; T. Itagaki; N. Katsushima; S. Ito; Y. Matsuzaki; M. Okamoto; H. Nishimura; Y. Aoki; T. Murata; H. Hoshina; S. Hongo; K. Ootani

2007-01-01

60

Feasibility of using the Vero SBRT system for intracranial SRS.  

PubMed

The Vero SBRT system was benchmarked in a planning study against the Novalis SRS system for quality of delivered dose distributions to intracranial lesions and assessing the Vero system's capacity for SRS. A total of 27 patients with one brain lesion treated on the Novalis system, with 3 mm leaf width MLC and C-arm gantry, were replanned for Vero, with a 5 mm leaf width MLC mounted on an O-ring gantry allowing rotations around both the horizontal and vertical axis. The Novalis dynamic conformal arc (DCA) planning included vertex arcs, using 90° couch rotation. These vertex arcs cannot be reproduced with Vero due to the mechanical limitations of the O-ring gantry. Alternative class solutions were investigated for the Vero. Additionally, to distinguish between the effect of MLC leaf width and different beam arrangements on dose distributions, the Vero class solutions were also applied for Novalis. In addition, the added value of noncoplanar IMRT was investigated in this study. Quality of the achieved dose distributions was expressed in the conformity index (CI) and gradient index (GI), and compared using a paired Student's t-test with statistical significance for p-values ? 0.05. For lesions larger than 5 cm3, no statistical significant difference in conformity was observed between Vero and Novalis, but for smaller lesions, the dose distributions showed a significantly better conformity for the Novalis (?CI = 13.74%, p = 0.0002) mainly due to the smaller MLC leaf width. Using IMRT on Vero reduces this conformity difference to nonsignificant levels. The cutoff for achieving a GI around 3, characterizing a sharp dose falloff outside the target volume was 4 cm3 for Novalis and 7 cm3 for Vero using DCA technique. Using noncoplanar IMRT, this threshold was reduced to 3 cm3 for the Vero system. The smaller MLC and the presence of the vertex fields allow the Novalis system to better conform the dose around the lesion and to obtain steeper dose falloff outside the lesion. Comparable dosimetric characteristics can be achieved with Vero for lesions larger than 3 cm3 and using IMRT. PMID:24423838

Burghelea, Manuela; Verellen, Dirk; Gevaert, Thierry; Depuydt, Tom; Poels, Kenneth; Simon, Viorica; De Ridder, Mark

2014-01-01

61

Spheroplast formation and partial purification of microbodies from hydrocarbon-grown cells of Cladosporium resinae  

Microsoft Academic Search

Summary Cells ofCladosporium resinae form greater numbers of microbodies when grown onn-alkanes than when grown on glucose. To facilitate isolation of microbodies, hydrocarbon-grown cells were spheroplasted. Of four spheroplasting agents and five osmotic supports examined, best results were obtained after a 4-h incubation with Novozym 234 plus chitinase and with 0.8 M sorbitol as osmotic support. Equal numbers of spheroplasts

David B. Carson; Joseph J. Cooney

1988-01-01

62

Multiband spectral emitters matched to MBE grown photovoltaic cells  

NASA Astrophysics Data System (ADS)

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 Yb2O3 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-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, Er2O3/Ho2O3 and Er2O3/Yb2O3, 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 Er2O3/Ho2O3 emitters in which the concentration of Er2O3 and Ho2O3 were varied. The results demonstrated promise for further work.

Wong, Eva M.; Hickey, Jeffrey P.; Holmquist, Glenn A.; Uppal, Parvez N.; Waldman, Cye H.

1996-02-01

63

Multiband spectral emitters matched to MBE grown photovoltaic cells  

SciTech Connect

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.}

Wong, E.M.; Hickey, J.P.; Holmquist, G.A. [Quantum Group Inc., 11211 Sorrento Valley Road, San Diego, California 92121-1324 (United States); Uppal, P.N. [Lockhead-Martin Labs., 1450 South Rolling Road, Baltimore, Maryland 21227-3898 (United States); Waldman, C.H. [Consultant, P.O. Box 231157, San Diego, California 92023-1157 (United States)

1996-02-01

64

Aligned Cell Sheets Grown on Thermo-Responsive Substrates with Microcontact Printed Protein Patterns  

E-print Network

Aligned Cell Sheets Grown on Thermo-Responsive Substrates with Microcontact Printed Protein­4] but ideally, engineered tissues would be made entirely of biological components. Cell sheet engineering techniques address this challenge as they rely on cells to produce their own extracellular matrix (ECM).[5

65

Lipids of Pseudomonas aeruginosa Cells Grown on Hydrocarbons and on Trypticase Soy Broth1  

PubMed Central

Lipids were extracted from cells of Pseudomonas aeruginosa grown on a pure hydrocarbon (tridecane), mixed hydrocarbons (JP-4 jet fuel), and on Trypticase Soy Broth. Total lipids produced from each substrate represented from 7.1 to 8.2% of cellular dry weight, of which 5.0 to 6.4% were obtained before cellular hydrolysis (free lipids) and 1.7 to 2.0% were extracted after cellular hydrolysis (bound lipids). Free lipids from cells grown on each medium were separated into four fractions by thin-layer chromatography. All fractions were present in cells from each type of medium, and the “neutral fraction” constituted the largest fraction. The fatty acid composition of free lipids was determined by gas-liquid chromatography. Cells grown on each medium contained saturated and unsaturated C14 to C20 fatty acids. Trace amounts of C13 fatty acids were found in tridecane-grown cells. Saturated C16 and C18 were the major acids present in all cells. Quantitative differences were found in fatty acids produced on the three media, but specific correlations between substrate carbon sources and fatty acid content of cells were not evident. Tridecane-grown cells contained only traces of C13 acid and small amounts of C15 and C17 acids, suggesting that the organism's fatty acids were derived from de novo synthesis rather than by direct incorporation of the hydrocarbon. PMID:4976464

Edmonds, Paul; Cooney, J. J.

1969-01-01

66

Use of cyanobacterial gas vesicles as oxygen carriers in cell culture  

Microsoft Academic Search

The gas vesicles isolated from the cells of filamentous cyanobacterium Anabaena flos-aquae were treated and sterilized with glutaraldehyde and then evaluated for their effectiveness as gas carriers in cell culture.\\u000a Anchorage-dependent Vero cells were grown in a packed bed of microcarrier beads under the perfusion of Dulbecco’s Modified\\u000a Eagle’s Medium with 1% serum. The culture medium supplemented with 1.8% (v\\/v)

Anand Sundararajan; Lu-Kwang Ju

2006-01-01

67

Comparison of saftey and immunogenicity of purified chick embryo cell rabies vaccine (PCECV) and purified vero cell rabies vaccine (PVRV) using the Thai Red Cross intradermal regimen at a dose of 0.1 ML.  

PubMed

Intradermal (ID) vaccination with modern cell culture rabies vaccines is a means to significantly reduce the cost of post-exposure prophylaxis as compared to intramuscular vaccination. In this study we evaluated the efficacy, immunogenicity and tolerability of PCECV and PVRV administered ID in doses of 0.1 mL per site according to the 2-site Thai Red Cross (TRC) regimen. Patients with WHO category III exposure to suspect or laboratory proven rabid animals were administered either PCECV (n = 58) or PVRV (n = 52) ID at a dose of 0.1 mL per site at two sites on days 0, 3 and 7 and at one site on days 30 and 90. Serum samples were withdrawn on days 0, 14, 30, 90 and 180 and rabies virus neutralizing antibody (RVNA) titers were determined by rapid fluorescent focus inhibition test (RFFIT). Patients who were exposed to laboratory confirmed rabid animals were followed up for one year after exposure. All 110 patients developed RVNA titers above 0.5 IU/mL by day 14. Adequate titers >0.5 IU/mL were maintained up to day 180. Both vaccines induced equivalent RVNA titers at all time points and were well tolerated. Five subjects who were bitten by laboratory confirmed rabid dogs were alive and healthy one year after exposure. As demonstrated, PCECV and PVRV are both immunogenic, efficacious and well tolerated when administered in the TRC post-exposure prophylaxis regimen in ID doses of 0.1 mL as recommended by WHO guidelines. The use of PCECV in this regimen may prove more economical in developing countries like India. PMID:17035734

Madhusudana, Shampur N; Sanjay, Thitamaranahalli V; Mahendra, Bangalore J; Sudarshan, Mysore K; Narayana, Doddabele H Ashwath; Giri, Anand; Muhamuda, Kader; Ravi, Vasanthapuram; Vakil, Hoshang B; Malerczyk, Cladius

2006-01-01

68

Sodium channels in cultured neuroblastoma cells grown in high glucose or L-fucose.  

PubMed

Patch clamp techniques were used to record whole cell and single channel Na+ currents from NB41A3 neuroblastoma cells grown in culture. Cells were grown for two weeks in control medium or medium supplemented with 30 mM D-glucose of 30 mM L-fucose. Cells exposed to glucose or L-fucose had smaller whole cell Na+ currents than cells grown in unsupplemented medium, consistent with earlier studies (Yorek, Stefani & Wachtel, 1994). Whole cell macroscopic currents showed no change in activation or inactivation kinetics. Single channel current properties and opening probability were also unchanged. The number of [3H]saxitoxin binding sites, and therefore the total number of Na+ channels, was not reduced in cells grown in glucose or L-fucose (Yorek et al., 1994). Therefore, we conclude that some of the channels must have been rendered nonfunctional by the conditioning media. The finding that single channel properties are not altered suggests that channels become nonfunctional in an all-or-none manner. PMID:7563020

Wachtel, R E; Kraske, S A; Yorek, M A

1995-05-01

69

Single cell protein production by photosynthetic bacteria grown on the clarified effluents of biogas plant  

Microsoft Academic Search

Anaerobically digested cow dung was separated by centrifugation into solid residue and liquid supernatant fractions. Clarified supernatant fraction, rich in volatile fatty acids, supported the growth of photosynthetic bacteria. Single cell protein from different photosynthetic bacteria, grown on clarified supernatant, was found to be rich in essential and sulphur amino acids. Rhodopseudomonas capsulata produced the best single cell protein.

Sudhanshu Vrati; G. B. Pant

1984-01-01

70

Efficacy and safety of cell associated vaccines against Marek's disease virus grown in a continuous cell line from chickens.  

PubMed

The Marek's disease virus (MDV) vaccine strains CVI 988 and herpes virus of turkeys (HVT) strain FC126, usually are grown in primary chicken embryo fibroblasts (CEF). We found that the strains could be grown also in the so-called JBJ-1 cell line to titres in the same range as when chicken embryo fibroblasts were used. The JBJ-1 cell line is a fibroblast-like continuous chicken cell line, which can be grown in flat bottom tissue culture flasks, roller bottles and on micro carriers. We investigated the efficacy of experimental CVI 988 vaccines grown in JBJ-1 cells and the efficacy of combinations of CVI 988 grown in JBJ-1 cells with HVT FC 126 also grown in JBJ-1 cells. The study was performed in accordance with European Pharmacopoeia monograph 0589 for live MDV disease vaccines. Groups of 1-day-old SPF chicks were vaccinated subcutaneously or intramuscularly, with 10(2.5) TCID50 per dose of CVI 988 alone or in combination with 500PFU per dose of HVT. As a control a group vaccinated with CVI 988 grown in CEF was included. One group was not vaccinated. Five days after vaccination all chickens were challenged with the very virulent MDV strain RB1B. After challenge the chickens were observed for a period of 70 days for signs of Marek's disease (MD). The protection induced by CVI 988 grown in JBJ-1 cells and the combination of CVI 988 and HVT-FC126 both grown in JBJ-1 cells, amply complied with the requirements of the European Pharmacopoeia which prescribes that the protection index should be at least 80%. The safety of the vaccines grown in JBJ-1 cells was tested in a field study in commercial layer chickens. No signs of MD were noticed during the study and no other signs attributable to the vaccine. It is concluded that the JBJ-1 cell line is a suitable substrate for the current vaccines against MD. PMID:18706949

Geerligs, Harm; Quanz, Sandra; Suurland, Brenda; Spijkers, Ine E M; Rodenberg, Jeff; Davelaar, Frans G; Jongsma, Berend; Kumar, Mahesh

2008-10-16

71

A serum-free Vero production platform for a chimeric virus vaccine candidate.  

PubMed

MedImmune Vaccines has engineered a live, attenuated chimeric virus that could prevent infections caused by parainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV), causative agents of acute respiratory diseases in infants and young children. The work here details the development of a serum-free Vero cell culture production platform for this virus vaccine candidate. Efforts to identify critical process parameters and optimize culture conditions increased infectious virus titers by approximately 2 log(10) TCID(50)/ml over the original serum-free process. In particular, the addition of a chemically defined lipid concentrate to the pre-infection medium along with the shift to a lower post-infection cultivation temperature increased virus titers by almost 100-fold. This improved serum-free process achieved comparable virus titers to the serum-supplemented process, and demonstrated consistent results upon scale-up: Vero cultures in roller bottles, spinner flasks and bioreactors reproducibly generated maximum infectious virus titers of 8 log(10) TCID(50)/ml. PMID:19002888

Yuk, Inn H; Lin, Gina B; Ju, Hui; Sifi, Inesse; Lam, Yvonne; Cortez, Armida; Liebertz, Danny; Berry, J Michael; Schwartz, Richard M

2006-07-01

72

Multiband spectral emitters matched to MBE grown photovoltaic cells  

Microsoft Academic Search

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 Yb2O3 is well matched to the band gap of Si;

Eva M. Wong; Jeffrey P. Hickey; Glenn A. Holmquist; Parvez N. Uppal; Cye H. Waldman

1996-01-01

73

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

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

74

Sonochemically grown ZnO nanowalls on Graphene layers as Photoanode in Dye sensitized Solar cells.  

E-print Network

on to FTO via chemical process. We employed a novel seed layer-free sonochemical technique to synthesize ZnOSonochemically grown ZnO nanowalls on Graphene layers as Photoanode in Dye sensitized Solar cells. Here we report on a direct growth method of ZnO nanostructures on untreated Graphene over Fluorine

Pala, Nezih

75

Efficacy and safety of cell-associated vaccines against Marek's disease virus grown in QT35 cells or JBJ-1 cells.  

PubMed

The Marek's disease virus (MDV) vaccine strain CVI 988 usually is grown in primary chicken embryo fibroblasts (CEFs). We found that the strains could be grown also in the QT35 and JBJ-1 cell lines to titers in the same range as in the CEFs. Both cell lines are fibroblast-like cell lines, which can be grown in flat-bottomed tissue-culture flasks, roller bottles, and on microcarriers. For growth in QT35 cells it was necessary to adapt the virus to the cell line; for growth in JBJ-1 cells this was not necessary. We investigated the efficacy of experimental CVI 988 vaccines grown in QT35 cells and JBJ-1 cells. The efficacy studies were performed in accordance with European Pharmacopoeia (EP) monograph for live MDV disease vaccines. Groups of 1-day-old specific-pathogen-free chicks were vaccinated. Nonvaccinated control groups were included in the studies. Five to 7 days after vaccination all chickens were challenged with the very virulent MDV strain RB1B. After challenge the chickens were observed for a period of 70 days for signs of MD. The protection induced by CVI 988 grown in QT35 cells as well as JBJ-1 cells complied with the requirements of the EP that prescribe that the protection index should be at least 80%. The safety of the vaccines grown in QT35 cells and JBJ-1 cells was tested in a field study in commercial layer chickens. The vaccine virus was not safe after passaging in QT35 cells. This can be explained by the presence of fragments of the genome of MDV strains in the QT35 cell line. No signs of MD were noticed in the study in which CVI988 grown in JBJ-1 cells was tested. It is concluded that the JBJ-1 cell line is a suitable substrate for the current vaccines against MD. PMID:23901760

Geerligs, Harm; Spijkers, Ine; Rodenberg, Jeff

2013-06-01

76

Four-dimensional imaging of filter-grown polarized epithelial cells.  

PubMed

Understanding how epithelial cells generate and maintain polarity and function requires live cell imaging. In order for cells to become fully polarized, it is necessary to grow them on a permeable membrane filter; however, the translucent filter obstructs the microscope light path required for quantitative live cell imaging. Alternatively, the membrane filter may be excised but this eliminates selective access to apical and basolateral surfaces. Conversely, epithelial cells cultured directly on glass exhibit different phenotypes and functions from filter grown cells. Here, we describe a new method for culturing polarized epithelial cells on a Transwell filter insert that allows superior live cell imaging with spatial and temporal image resolution previously unachievable using conventional methods. Cells were cultured on the underside of a filter support. Epithelial cells grown in this inverted configuration exhibit a fully polarized architecture, including the presence of functional tight junctions. This new culturing system permits four-dimensional (three spatial dimension over time) imaging of endosome and Golgi apparatus dynamics, and permits selective manipulation of the apical and basolateral surfaces. This new technique has wide applicability for visualization and manipulation of polarized epithelial cells. PMID:17308935

Wakabayashi, Yoshiyuki; Chua, Jennifer; Larkin, Janet M; Lippincott-Schwartz, Jennifer; Arias, Irwin M

2007-05-01

77

Photoelectrochemical cell using dye sensitized zinc oxide nanowires grown on carbon fibers  

NASA Astrophysics Data System (ADS)

Zinc oxide (ZnO) nanowires (NWs) grown on carbon fibers using a vapor transport and condensation approach are used as the cathode of a photoelectrochemical cell. The carbon fibers were obtained by electrospray deposition and take the form of a flexible carbon fabric. The ZnO NW on carbon fiber anode is combined with a "black dye" photoabsorber, an electrolyte, and a platinum (Pt) counterelectrode to complete the cell. The results show that ZnO NW and carbon fibers can be used for photoinduced charge separation/charge transport and current collection, respectively, in a photoelectrochemical cell.

Unalan, Husnu Emrah; Wei, Di; Suzuki, Kenichi; Dalal, Sharvari; Hiralal, Pritesh; Matsumoto, Hidetoshi; Imaizumi, Shinji; Minagawa, Mie; Tanioka, Akihiko; Flewitt, Andrew J.; Milne, William I.; Amaratunga, Gehan A. J.

2008-09-01

78

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Indian River at Vero Beach, Fla. 110.73b Section 110.73b Navigation and Navigable...Special Anchorage Areas § 110.73b Indian River at Vero Beach, Fla. (a) Area A. Beginning at a point located on the...

2011-07-01

79

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Indian River at Vero Beach, Fla. 110.73b Section 110.73b Navigation and Navigable...Special Anchorage Areas § 110.73b Indian River at Vero Beach, Fla. (a) Area A. Beginning at a point located on the...

2013-07-01

80

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Indian River at Vero Beach, Fla. 110.73b Section 110.73b Navigation and Navigable...Special Anchorage Areas § 110.73b Indian River at Vero Beach, Fla. (a) Area A. Beginning at a point located on the...

2012-07-01

81

FRABEL's REIMAGINED at McKEE BOTANICAL GARDEN 350 US FEDERAL HIGHWAY, VERO BEACH  

E-print Network

FRABEL's REIMAGINED at McKEE BOTANICAL GARDEN 350 US FEDERAL HIGHWAY, VERO BEACH TUESDAY, MARCH 12:45 Arrive at McKee Botanical Garden. I will gather all reciprocal garden passes prior to entering) east to US 1. Go North on US 1 to Vero Beach. McKee Botanical Garden is located at 350 US Highway 1

Hill, Jeffrey E.

82

Thin base-layer single crystal silicon solar cells with ECR plasma CVD grown emitters  

Microsoft Academic Search

Thin (~16 µm) base-layer monocrystalline silicon solar cells have been investigated with microcrystalline or epitaxial n-type emitters grown at low temperatures ({<}550 °C) by electron cyclotron resonance (ECR) plasma-enhanced chemical vapour deposition (PECVD). The p-type, 1-2 Omegacm, base layers were epitaxially deposited by conventional thermal CVD onto monocrystalline Si p+ substrates. An efficiency of 13.72% was achieved in the best

L. Wang; H. S. Reehal

2001-01-01

83

Performance of silicon solar cells fabricated from multiple Czochralski ingots grown by using a single crucible  

NASA Technical Reports Server (NTRS)

Results on the performance of solar cells fabricated on wafers from multiple silicon ingots of large diameter, grown by using a single crucible and a sequential melt replenishment Czochralski (CZO) technique are presented. Samples were analyzed for resistivity, dislocation density and impurity content. Solar cells were fabricated from the seed, center and tang end of each ingot to evaluate the growth reproducibility and material quality. The cell efficiency within a given wafer varies by no more than plus or minus 5% of the average value. A small but consistent decrease in the cell efficiency is observed from the first to the fourth ingot grown from a single crucible. This decrease may be related to an increase in impurity content or dislocation density or a combination of both. The efficiency of the cells fabricated from the tang end of the fourth ingot is about 10% lower than that of the control cell. An impurity effects model is employed to correlate this decrease in efficiency with the impurity build-up in the residual melt.

Kachare, A. H.; Uno, F. M.; Miyahira, T.; Lane, R. L.

1980-01-01

84

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

PubMed Central

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

Katai, Emese; Yahiro, Rikki K. K.; Poor, Viktor S.; Montsko, Gergely; Zrinyi, Zita; Kovacs, Gabor L.; Miseta, Attila

2013-01-01

85

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

SciTech Connect

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.

Grdina, D.J.; Hunter, N.

1982-10-01

86

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

SciTech Connect

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.

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

2011-01-01

87

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

NASA Astrophysics Data System (ADS)

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.

Li, Wei; Varlamov, Sergey; Xue, Chaowei

2014-09-01

88

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

SciTech Connect

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.

Grdina, D.J.; Hunter, N.

1982-10-01

89

Comparative studies of two membrane fractions isolated from chemotrophically and phototrophically grown cells of Rhodopseudomonas capsulata.  

PubMed Central

Light and heavy membrane fractions have been isolated by equilibrium sucrose density centrifugation from Rhodopseudomonas capsulata 938 GCM grown aerobically in the dark (chemotrophically) and anaerobically in the light (phototrophically). The densities of the light and heavy fractions from phototrophic cells were 1.1004 to 1.1006 and 1.1478, respectively, and the densities of the light and heavy fractions from chemotrophic cells were 1.0957 to 1.0958 and 1.1315, respectively. Both fractions were active in photochemical and respiratory functions and in electron transport-coupled phosphorylation. The light membrane fraction isolated from chemotrophic cells contained the reaction center and the light-harvesting pigment-protein complex B 870, but not the variable light-harvesting complex B 800-850. A small amount of the complex B 800-850 was present in the light fraction isolated from phototrophically grown cells, but it was not energetically coupled to the photosynthetic apparatus. From inhibitor studies, difference spectroscopy, and measurement of enzyme activities it was tentatively concluded that the light membrane fraction contains only the reduced nicotinamide adenine dinucleotide-oxidizing electron transport chain having a KCN-insensitive, low-potential cytochrome c oxidase, whereas the heavy fraction contains additionally the succinate dehydrogenase and a high-potential cytochrome b terminal oxidase sensitive to KCN. The light membrane fraction was more labile than the heavy fraction in terms of phosphorylating activity. PMID:7204341

Garcia, A F; Drews, G; Reidl, H H

1981-01-01

90

Assessing individual radial junction solar cells over millions on VLS-grown silicon nanowires  

NASA Astrophysics Data System (ADS)

Silicon nanowires (SiNWs) grown on low-cost substrates provide an ideal framework for the monolithic fabrication of radial junction photovoltaics. However, the quality of junction formation over a random matrix of SiNWs, fabricated via a vapor-liquid-solid (VLS) mechanism, has never been assessed in a realistic context. To address this, we probe the current response of individual radial junction solar cells under electron-beam and optical-beam excitations. Excellent current generation from the radial junction units, compared to their planar counterparts, has been recorded, indicating a high junction quality and effective doping in the ultra-thin SiNWs with diameters thinner than 20 nm. Interestingly, we found that the formation of radial junctions by plasma deposition can be quite robust against geometrical disorder and even the crossings of neighboring cell units. These results provide a strong support to the feasibility of building high-quality radial junction solar cells over high-throughput VLS-grown SiNWs on low-cost substrates.

Yu, Linwei; Rigutti, Lorenzo; Tchernycheva, Maria; Misra, Soumyadeep; Foldyna, Martin; Picardi, Gennaro; Cabarrocas, Pere Roca i.

2013-07-01

91

Morphological and ultrastructural changes in vegetative cells and heterocysts of Anabaena variabilis grown with fructose.  

PubMed Central

The morphology and ultrastructure of Anabaena variabilis grown in medium with and without 40 mM fructose were compared. Vegetative cells and young heterocysts in fructose-supplemented medium were significantly larger, were filled with glycogen granules, and had fewer thylakoids. Developing heterocysts contained large numbers of glycogen granules well into mature stages, and envelope formation was precocious. As heterocysts enlarged in fructose medium, their shape became more broadly oblong compared with the more rectangular heterocysts in fructose-free medium. Images PMID:3100507

Lang, N J; Krupp, J M; Koller, A L

1987-01-01

92

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

SciTech Connect

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.

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

2012-06-01

93

Subcellular fractionation and morphology of calf aortic smooth muscle cells: studies on whole aorta, aortic explants, and subcultures grown under  

PubMed Central

A comparative biochemical and morphological study was made of calf aortic smooth muscle cells found in situ and grown in vitro under various conditions. Striking alterations in enzyme contents, physical properties, and morphological appearances of lysosomes, endoplasmic reticulum, plasma membranes and, to a lesser extent, mitochondria were observed upon culturing of calf aortic smooth muscle cells. These changes first appeared in cells growing out of tissue explants. They developed further upon subculturing of the cells and depended greatly on the culture conditions used. The alterations included increases in specific activities of some 5- to 25-fold of four acid hydrolases, an average ninefold increase in 5' -nucleotidase, sevenfold increase in cytochrome oxidase, and fourfold increase in neutral ?-glucosidase in subcultured smooth muscle cells compared to aortic cells in situ. Cell fractionation studies showed significant shifts in the equilibrium densities of plasma membranes, microsomes, and lysosomes, but not of mitochondria, in smooth muscle cells growing out from explants and in subcultured cells, compared to cells isolated from intact aortas. Although the cells grown in vitro exhibited typical phenotypic features of smooth muscle cells such as abundant myofilaments and surface vesicles, alterations in the morphological appearance of the endoplasmic reticulum, Golgi apparatus, and, especially, lysosomes were observed. These results demonstrate significant differences in specific cellular characteristics and functions of aortic smooth muscle cells grown in vitro compared to aortic cells in situ. PMID:199607

Fowler, S; Shio, H; Wolinsky, H

1977-01-01

94

Enhanced chemoresistance of squamous carcinoma cells grown in 3D cryogenic electrospun scaffolds.  

PubMed

It is critically important to study head and neck squamous cell carcinoma tumorigenic mechanisms in order to gain a better understanding of tumor development, progression, and treatment. Unfortunately, a representative three-dimensional (3D) model for these evaluations has yet to be developed. The purpose of this study was to replicate tumor extracellular matrix (ECM) morphology utilizing electrospinning technology. First, the tumor ECM was evaluated by decellularizing tumor samples and analyzing the fibrous structure of the ECM by scanning electron microscopy. Cryogenic electrospun silk scaffolds were then fabricated to mimic the tumor ECM, and were found to be similar in fiber orientation and fiber dimensions to the native tumor ECM. Tumor cells were cultured on these ECM mimicking scaffolds and compared to an in vivo model of the same derivative human tumor in terms of proliferation and differentiation. The tumor cells in the 3D model show similar phenotypes to those found in vivo, contrasting to the same cells grown in two-dimensional (2D) culture. The sensitivity of the tumor cells to paclitaxel was compared between 2D culture and 3D culture. The results indicate that increased drug concentrations, orders of magnitude higher than the IC90 for 2D culture, had minimal effects on HN12 cell viability in the 3D model. In conclusion, an in vitro tumor model has been developed that will allow for a better understanding of tumor biology and aid chemotherapeutic drug development and accurate evaluation of drug efficacy. PMID:24057893

Bulysheva, Anna A; Bowlin, Gary L; Petrova, Stella P; Yeudall, W Andrew

2013-10-01

95

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

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

96

Label-free optical detection of cells grown in 3D silicon microstructures.  

PubMed

We demonstrate high aspect-ratio photonic crystals that could serve as three-dimensional (3D) microincubators for cell culture and also provide label-free optical detection of the cells. The investigated microstructures, fabricated by electrochemical micromachining of standard silicon wafers, consist of periodic arrays of silicon walls separated by narrow deeply etched air-gaps (50 ?m high and 5 ?m wide) and feature the typical spectral properties of photonic crystals in the wavelength range 1.0-1.7 ?m: their spectral reflectivity is characterized by wavelength regions where reflectivity is high (photonic bandgaps), separated by narrow wavelength regions where reflectivity is very low. In this work, we show that the presence of cells, grown inside the gaps, strongly affects light propagation across the photonic crystal and, therefore, its spectral reflectivity. Exploiting a label-free optical detection method, based on a fiberoptic setup, we are able to probe the extension of cells adherent to the vertical silicon walls with a non-invasive direct testing. In particular, the intensity ratio at two wavelengths is the experimental parameter that can be well correlated to the cell spreading on the silicon wall inside the gaps. PMID:23817434

Merlo, Sabina; Carpignano, Francesca; Silva, Gloria; Aredia, Francesca; Scovassi, A Ivana; Mazzini, Giuliano; Surdo, Salvatore; Barillaro, Giuseppe

2013-08-21

97

Investigation of Indium Gallium Nitride Grown via Metal Organic Chemical Vapor Deposition in Various Crystallographic Orientations for Solar Cell Applications  

NASA Astrophysics Data System (ADS)

Solar cell technology has long relied upon Si and GaAs based materials. While this industry is mature, it has approached a plateau in the push to increase efficiency. It has been proposed that the InGaN ternary materials system is ideal for this purpose. In this work we report on the growth, fabrication and testing of photovoltaic properties of InGaN based solar cells grown via metalorganic chemical vapor deposition (MOCVD). In order for solar cells to work effectively, a minimum active region thickness is necessary for sufficient absorption of photons for conversion. At low In content compositions, high quality material has been grown and a simple p-i-n type solar cell with a single absorbing layer can be produced. However, at high In content compositions critical thickness limits for the thin films are well below the thickness requirements for full absorption. High In compositions are necessary to efficiently match the solar spectrum when designing multijunction solar cells. Solar cells require a thickness of 100-200 nm for sufficient absorption. Growth optimization and results for p-i-n type: single double heterostructures, multiple double heterostructure (MDH), and MQW, solar cells will be reported for InGaN grown on sapphire in the +c [0001] orientation as well as InGaN grown on bulk m-plane (10-10) substrates. Non-polar oriented growth of InGaN was investigated since as In content increases in typical c-plane growth, the polarization fields in the double heterostructure design of the p-i-n solar cell oppose the built in field of the junction and could potentially hinder carrier collection. At low In content, m-plane InGaN solar cells outperform c-plane solar cells with the same composition due to the higher quality material grown homoepitaxially on bulk GaN substrates.

Cruz, Samantha Christine

98

Electrochemically grown ZnO nanorods for hybrid solar cell applications  

SciTech Connect

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)

Hames, Yakup [Department of Electrical-Electronics Engineering, Mustafa Kemal University, 31040 Hatay (Turkey); Alpaslan, Zuehal; Koesemen, Arif; San, Sait Eren; Yerli, Yusuf [Department of Physics, Gebze Institute of Technology, 41400 Gebze (Turkey)

2010-03-15

99

Carriers transport properties in GaInP solar cells grown by molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

The transport properties of carriers in GaInP solar cells grown by molecular beam epitaxy are investigated by temperature-dependent current-voltage (I-V) measurements. In contrast to GaInP/AlGaInP heterostructure, a long PL decay time is observed in GaInP/AlInP, which is ascribed to a lower interface recombination due to an improved carriers' confinement in the case of the high-energy barrier. However, the series resistance induced by the high potential barrier at GaInP/AlInP interface due to a big valence band offset prevents the improvement of solar cell's performance. An S-shape like I-V characteristic observed at low temperatures indicates that the transport of major carriers is limited by the barrier. A calculation based on the combination of a normal photovoltaic device with a barrier-affected thermal carriers transport explicitly explains this abnormal I-V characteristic. Our study demonstrates the critical role of the barrier-induced series resistance in the determination of solar cell's performance.

Dai, P.; Lu, S. L.; Arimochi, M.; Uchida, S.; Watanabe, T.; Luo, X. D.; Yang, H.

2014-12-01

100

Flexible dye-sensitized solar cells with ZnO nanoparticles grown by Sonochemistry over Graphene/PET substrates.  

E-print Network

for FDSSCs. We employed a novel seed layer-free sonochemical technique to synthesize ZnO nanostructuresFlexible dye-sensitized solar cells with ZnO nanoparticles grown by Sonochemistry over Graphene report on fabrication of ZnO nanostructure over Graphene/PET substrates to be used as photoelectrodes

Pala, Nezih

101

Antrodia camphorata Grown on Germinated Brown Rice Suppresses Melanoma Cell Proliferation by Inducing Apoptosis and Cell Differentiation and Tumor Growth  

PubMed Central

Antrodia camphorata grown on germinated brown rice (CBR) was prepared to suppress melanoma development. CBR extracts were divided into hexane, EtOAc, BuOH, and water fractions. Among all the fractions, EtOAc fraction showed the best suppressive effect on B16F10 melanoma cell proliferation by CCK-8 assay. It also showed the increased cell death and the changed cellular morphology after CBR treatment. Annexin V-FITC/PI, flow cytometry, and western blotting were performed to elucidate anticancer activity of CBR. The results showed that CBR induced p53-mediated apoptotic cell death of B16F10. CBR EtOAc treatment increased melanin content and melanogenesis-related proteins of MITF and TRP-1 expressions, which supports its anticancer activity. Its potential as an anticancer agent was further investigated in tumor-xenografted mouse model. In melanoma-xenografted mouse model, melanoma tumor growth was significantly suppressed under CBR EtOAc fraction treatment. HPLC analysis of CBR extract showed peak of adenosine. In conclusion, CBR extracts notably inhibited B16F10 melanoma cell proliferation through the p53-mediated apoptosis induction and increased melanogenesis. These findings suggest that CBR EtOAc fraction can act as an effective anticancer agent to treat melanoma. PMID:23533475

Song, Minjung; Park, Dong Ki; Park, Hye-Jin

2013-01-01

102

Antioxidant activity of Haematococcus pluvialis cells grown in continuous culture as a function of their carotenoid and fatty acid content  

Microsoft Academic Search

The influence of culture conditions on the quality of Haematococcus pluvialis biomass is assessed. Continuously grown cells have been characterised with respect to their astaxanthin, fatty acid content,\\u000a and antioxidant activity and compared with those of non-growing haematocysts. Moderate limitation of nitrate availability\\u000a (1.7 mM) under continuous growth conditions favoured the production of reddish palmelloid cells whose extracts possessed antioxidant\\u000a activity

M. C. Cerón; M. C. García-Malea; J. Rivas; F. G. Acien; J. M. Fernandez; E. Del Río; M. G. Guerrero; E. Molina

2007-01-01

103

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

Microsoft Academic Search

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-amino- phenoxazine-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

JIAN-SHEN ZHAO; AJAY SINGH; XIAO-DONG HUANG; OWEN P. WARD

2000-01-01

104

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

SciTech Connect

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.

Hehlgans, Stephanie [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany) [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Department of Radiotherapy and Oncology, University of Frankfurt, Frankfurt am Main (Germany); Institute of Radiopharmacy, Helmholtz Center Dresden-Rossendorf, Dresden (Germany); Eke, Iris [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany)] [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Cordes, Nils, E-mail: Nils.Cordes@OncoRay.de [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany) [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Institute of Radiopharmacy, Helmholtz Center Dresden-Rossendorf, Dresden (Germany); Department of Radiation Oncology, University Hospital and Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany)

2012-08-01

105

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

PubMed Central

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?

2014-01-01

106

The Effect of In Vivo Grown Corneal Epithelium Transplantation on Persistent Epithelial Defects with Limbal Stem Cell Deficiency  

PubMed Central

We report our experience with corneal epithelium, grown in vivo, transplantation in three patients with persistent epithelial defect (PED). The three patients had ocular surface disease unresponsive to standard treatments and were therefore chosen for transplantation. They underwent transplantation of epithelial sheets, grown in vivo, to the most affected eye. In vivo cultivation was carried out in the cornea of a living related donor. After epithelialization was completed, the epithelium grown on an amniotic membrane was harvested gently; it was then transplanted into the patient's eye after debridement of fibrovascular tissue. The cultivated epithelium was completely epithelialized by 2 weeks; it was well-differentiated with well-formed hemidesmosome. On immunohistochemical staining, p63, connexin 43, and Integrin ?4 were expressed in the cells on the epithelial sheet. The PED was covered completely and maintained for 4 weeks in all cases. However, corneal erosion recurred after 5 weeks in two cases. This novel technique demonstrates the corneal epithelial cells can be expanded in vivo successfully on denuded amniotic membrane of a healthy cornea and harvested safely. A corneal epithelial sheet, grown in vivo, can be transplanted to treat eye with a severe ocular surface disease, such as total limbal deficiency. PMID:18583889

Kim, Jee Taek; Chun, Yeoun Sook; Song, Geo Young

2008-01-01

107

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

SciTech Connect

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 not influence any of the investigated parameters under hypoxia.

Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin, E-mail: Albrecht@anaesthesie.uni-kiel.de

2012-04-15

108

THIN FILM SILICON FOR SOLAR CELL APPLICATION GROWN FROM LIQUID PHASE ON METALLURGICAL GRADE SILICON  

Microsoft Academic Search

Liquid phase epitaxy was applied to grow roughly 10 µm thick n-type polycrystalline silicon film on p-type metallurgical grade (MG) silicon substrate at 900° C in gallium\\/indium solution. GaAs, dissolved in the melt, served as an arsenic donor source for the as-grown film. The carrier concentration of both the substrate and the as- grown film was 1 × 1018 cm?3

H. G. Svavarsson; D. M. Danielsson; J. T. Gudmundsson

109

Influence of seed layer treatment on low temperature grown ZnO nanotubes: Performances in dye sensitized solar cells  

Microsoft Academic Search

Non-aligned and highly densely aligned ZnO nanotube (NTs), synthesized by low temperature solution method were applied as photoanode materials for the fabrication of efficient dye-sensitized solar cells (DSSCs). The crystalline and the morphological analysis revealed that the grown aligned ZnO NTs possessed a typical hexagonal crystal structure of outer and inner diameter ?250nm and ?100nm, respectively. ZnO seeding on FTO

Sadia Ameen; M. Shaheer Akhtar; Young Soon Kim; O-Bong Yang; Hyung-Shik Shin

2011-01-01

110

Cytochemical study of developing neurotransmitter properties of dissociated sympathetic neurons grown in co-culture with dissociated pineal cells.  

PubMed

We studied the development of neurotransmitter phenotype in sympathetic neurons grown in the presence of pinealocytes, a target tissue having adrenergic but not cholinergic receptors. Neurons, dissociated from neonatal rat superior cervical ganglia, were grown in co-culture with dissociated pineal cells. Both ganglionic and pineal non-neuronal background cells were allowed to grow nearly to confluency. Electron microscopic cytochemical techniques were used to examine sets of co-cultures at weekly intervals over 5 weeks. Adrenergic vesicles were identified by their dense granular precipitate following potassium permanganate fixation. We found that the percentage of small granular vesicles, both in synaptic boutons onto other neurons and in axonal varicosities, declined very little over 5 weeks. After an initial drop from 75 to 65%, the percentage of small granular vesicles remained remarkably constant. Throughout the 5 weeks, more than 70% of the boutons and varicosities contained a predominance of small granular vesicles; fewer than 20% contained a predominance of clear vesicles. Although both somal synaptic boutons and axonal varicosities retained a predominantly adrenergic ultrastructure, at certain weeks there was a statistically significant shift in the percent distribution of adrenergic vesicles in somal boutons compared with the distribution in axonal varicosities. Because these cultures were grown under conditions known to favor an induction of acetylcholine metabolism and a suppression of catecholamine metabolism, we conclude that the maintenance of adrenergic ultrastructure over 5 weeks may be due to the presence of the pineal cells. PMID:2872617

Phillips, C E; Freschi, J E

1986-04-01

111

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

PubMed

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

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

1995-02-20

112

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

SciTech Connect

We have grown device-quality epitaxial silicon thin films at growth rates up to 1.8 ?m/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.

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

2011-07-01

113

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

PubMed Central

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

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

2000-01-01

114

[The accumulation and degradation dynamics of cyanophycin in cyanobacteria grown in symbiotic associations with plant tissues and cells].  

PubMed

Five different artificial associations of cyanobacterial cells with the cells or tissues of nightshade and rauwolfia were studied. The associations grown on nitrogen-containing media produced heterocysts. Cyanobacterial cells in the associations retained their ability to take up bound nitrogen from the medium, to store it in the form of cyanophycin granules, and to use them in the process of symbiotic growth. The synthesis and degradation of cyanophycin granules in cyanobacterial cells were more active in the associations than in monocultures. In the symbiotic associations of Chlorogloeopsis fritschii ATCC 27193 with Solanum laciniatum cells and of Nostoc muscorum CALU 304 with the Rauwolfia serpentina callus, heterocysts were produced at 3- to 30-fold higher cyanophycin contents than in cyanobacterial monocultures. In contrast, in the association of N. muscorum CALU 304 with the Solanum dulcamara callus, heterocysts were produced at lower cyanophycin contents than in the N. muscorum CALU 304 monoculture. The degradation of cyanophycin granules in N. muscorum CALU 304 cells grown in associations with plant tissues or cells was subjected to mathematical analysis. The activation of cyanophycin degradation and heterocyst production in the associations N. muscorum CALU 304-R. serpentina and C. fritschii-S. laciniatum was accompanied by an enhanced synthesis of the nitrogen-containing alkaloids in plant cells. The data obtained suggest that an integrated system of nitrogen homeostasis can be formed in symbiotic associations. Depending on the growth stage of an association, its plant member can either stimulate the accumulation of bound nitrogen in vegetative cyanobacterial cells in the form of cyanophycin granules, or activate their degradation, or initiate the formation of heterocysts independently of the cyanobacterial sensory-signalling system. PMID:12901011

Gorelova, O A; Kle?menov, S Iu

2003-01-01

115

mtDNA depletion confers specific gene expression profiles in human cells grown in culture and in xenograft  

PubMed Central

Background Interactions between the gene products encoded by the mitochondrial and nuclear genomes play critical roles in eukaryotic cellular function. However, the effects mitochondrial DNA (mtDNA) levels have on the nuclear transcriptome have not been defined under physiological conditions. In order to address this issue, we characterized the gene expression profiles of A549 lung cancer cells and their mtDNA-depleted ?0 counterparts grown in culture and as tumor xenografts in immune-deficient mice. Results Cultured A549 ?0 cells were respiration-deficient and showed enhanced levels of transcripts relevant to metal homeostasis, initiation of the epithelial-mesenchymal transition, and glucuronidation pathways. Several well-established HIF-regulated transcripts showed increased or decreased abundance relative to the parental cell line. Furthermore, growth in culture versus xenograft has a significantly greater influence on expression profiles, including transcripts involved in mitochondrial structure and both aerobic and anaerobic energy metabolism. However, both in vitro and in vivo, mtDNA levels explained the majority of the variance observed in the expression of transcripts in glucuronidation, tRNA synthetase, and immune surveillance related pathways. mtDNA levels in A549 xenografts also affected the expression of genes, such as AMACR and PHYH, involved in peroxisomal lipid metabolic pathways. Conclusion We have identified mtDNA-dependent gene expression profiles that are shared in cultured cells and in xenografts. These profiles indicate that mtDNA-depleted cells could provide informative model systems for the testing the efficacy of select classes of therapeutics, such as anti-angiogenesis agents. Furthermore, mtDNA-depleted cells grown culture and in xenografts provide a powerful means to investigate possible relationships between mitochondrial activity and gene expression profiles in normal and pathological cells. PMID:18980691

Magda, Darren; Lecane, Philip; Prescott, Julia; Thiemann, Patricia; Ma, Xuan; Dranchak, Patricia K; Toleno, Donna M; Ramaswamy, Krishna; Siegmund, Kimberly D; Hacia, Joseph G

2008-01-01

116

"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)

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.

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

117

Collagen scaffolds with in situ-grown calcium phosphate for osteogenic differentiation of Wharton's jelly and menstrual blood stem cells.  

PubMed

The aim of this research was to investigate the osteogenic differentiation potential of non-invasively obtained human stem cells on collagen nanocomposite scaffolds with in situ-grown calcium phosphate crystals. The foams had 70% porosity and pore sizes varying in the range 50-200 µm. The elastic modulus and compressive strength of the calcium phosphate containing collagen scaffolds were determined to be 234.5 kPa and 127.1 kPa, respectively, prior to in vitro studies. Mesenchymal stem cells (MSCs) obtained from Wharton's jelly and menstrual blood were seeded on the collagen scaffolds and proliferation and osteogenic differentiation capacities of these cells from two different sources were compared. The cells on the composite scaffold showed the highest alkaline phosphatase activity compared to the controls, cells on tissue culture polystyrene and cells on collagen scaffolds without in situ-formed calcium phosphate. MSCs isolated from both Wharton's jelly and menstrual blood showed a significant level of osteogenic activity, but those from Wharton's jelly performed better. In this study it was shown that collagen nanocomposite scaffolds seeded with cells obtained non-invasively from human tissues could represent a potential construct to be used in bone tissue engineering. PMID:22744919

Karadas, Ozge; Yucel, Deniz; Kenar, Halime; Torun Kose, Gamze; Hasirci, Vasif

2014-07-01

118

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

Microsoft Academic Search

Summary 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 mossCeratodon purpureus. First, the volume fraction of each cell component was determined by stereology, and published values for component

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

2000-01-01

119

Surface antigens of rat liver epithelial cells grown in medium containing foetal bovine serum  

Microsoft Academic Search

Cultured rat liver cells induced a strong antibody response in syngeneic rats, directed against foetal calf serum components which were incorporated into the liver cell surface from the cell-culture medium. This antibody could be removed by absorption with liver cells or glutaraldehyde-fixed foetal calf serum. It is possible that the antigenic cross-reactivity observed in earlier studies with cultured cells treated

M J Embleton; P T Iype

1978-01-01

120

THE ISOLATION OF BOVINE EPHEMERAL FEVER VIRUS IN CELL CULTURES AND EVIDENCE FOR AUTOINTERFERENCE  

Microsoft Academic Search

Bovine ephemeral fever (BEF) virus was isolated from infected fresh cattle blood directly into Vero cell cultures. One cycle of rapid freezethaw destroyed the infectivity of the virus to Vero cells. The infectivity to baby mice by intracerebral inoculation, on the other hand, was only reduced. The occurrence of autointerferencc due to the presence of defective interfering particles in cell

S Tzipori

1975-01-01

121

Phosgene effects on F-actin in cells grown from pulmonary tissues  

SciTech Connect

Confocal laser microscopy has been used to study the effects of phosgene on cells of the lung. Results suggest that the F-actin cytoskeleton is a molecular target and sensitive indicator of phosgene toxicity. Ovine pulmonary artery endothelial cells, exposed at 0.145 to 5.39 x LCT(50) for sheep (3300 ppm.min) showed dose response decreases in F-actin content. Doses of 0.145 and 0.265 LCT(50) caused a significant (p < .01) 25% and 42% decrease in average F-actin per cell. Dense peripheral bands (DPBs) became indistinct at > or = 1.2 LCT(50) and disappeared at > or = 2.3 LCT(50). Organization of stress fibers was parallel to the cell's long axis and was not disrupted by < 1.21 LCT(50). In secretory cells from rat tracheal explants, studies indicate a threshold of resistance to phosgene at doses < 0.2 LCT(50). However, phosgene in excess of 0.2 LCT(50) produced precipitous decreases in secretory cell F-actin. Mature, contiguous populations of untreated secretory cells contained well defined DPBs and tightly connected cell-to-cell boundaries. Exposures to 1.0 and 1.5 LCT(50) did not disrupt boundaries between secretory cells but did cause separation of boundaries between secretory and other cell types. We conclude that concentration and organization are separate aspects of phosgene's effects on F-actin and that the lesions produced are cell-type specific.

Werrlein, R.J.; Madren-Whalley, J.; Kirby, S.D.

1993-05-13

122

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

PubMed Central

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

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

2013-01-01

123

Photosynthetic Nitrite Reduction as Influenced by the Internal Inorganic Carbon Pool in Air-Grown Cells of Synechococcus UTEX 625.  

PubMed

Photosynthetic reduction of NO2- was studied in air-grown cells of a cyanobacterium, Synechococcus UTEX 625. Addition of NO2- resulted in significant amounts of chlorophyll a fluorescence quenching both in the absence and presence of CO2, fixation inhibitors, glycolaldehyde or iodoacetamide. The degree of NO2- quenching was insensitive to the O2 concentration in the medium. Addition of 100 [mu]M inorganic carbon in the presence of glycolaldehyde and O2, leading to formation of the carbon pool within the cells, resulted in pronounced fluorescence quenching. Removal of O2 from the medium restored the fluorescence yield completely, and the subsequent addition of NO2- quenched 36% of the variable fluorescence. From the response to added 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the quenching by NO2- appeared to be photochemical quenching, and nonphotochemical quenching did not seem to be present. The reduction of NO2- observed on its addition to inorganic carbon-depleted cells remained uninfluenced by O2 or glycolaldehyde. The internal inorganic carbon pool in the cells stimulated NO2- reduction, both in the presence and absence of O2, by 4.8-fold. An increase in NO2- reduction by 0.5-fold was also observed in the presence of O2 during simultaneous assimilation of carbon and nitrogen in inorganic carbon-depleted cells. Contrary to this, under anaerobiosis, NO2- reduction was suppressed when carbon and nitrogen assimilation occurred together. PMID:12228476

Mir, N. A.; Salon, C.; Canvin, D. T.

1995-05-01

124

Photosynthetic Nitrite Reduction as Influenced by the Internal Inorganic Carbon Pool in Air-Grown Cells of Synechococcus UTEX 625.  

PubMed Central

Photosynthetic reduction of NO2- was studied in air-grown cells of a cyanobacterium, Synechococcus UTEX 625. Addition of NO2- resulted in significant amounts of chlorophyll a fluorescence quenching both in the absence and presence of CO2, fixation inhibitors, glycolaldehyde or iodoacetamide. The degree of NO2- quenching was insensitive to the O2 concentration in the medium. Addition of 100 [mu]M inorganic carbon in the presence of glycolaldehyde and O2, leading to formation of the carbon pool within the cells, resulted in pronounced fluorescence quenching. Removal of O2 from the medium restored the fluorescence yield completely, and the subsequent addition of NO2- quenched 36% of the variable fluorescence. From the response to added 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the quenching by NO2- appeared to be photochemical quenching, and nonphotochemical quenching did not seem to be present. The reduction of NO2- observed on its addition to inorganic carbon-depleted cells remained uninfluenced by O2 or glycolaldehyde. The internal inorganic carbon pool in the cells stimulated NO2- reduction, both in the presence and absence of O2, by 4.8-fold. An increase in NO2- reduction by 0.5-fold was also observed in the presence of O2 during simultaneous assimilation of carbon and nitrogen in inorganic carbon-depleted cells. Contrary to this, under anaerobiosis, NO2- reduction was suppressed when carbon and nitrogen assimilation occurred together. PMID:12228476

Mir, N. A.; Salon, C.; Canvin, D. T.

1995-01-01

125

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

PubMed

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

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

2014-02-01

126

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

127

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

128

Role of Proteases in the Release of Porcine Epidemic Diarrhea Virus from Infected Cells ?  

PubMed Central

Porcine epidemic diarrhea virus (PEDV), a causative agent of pig diarrhea, requires a protease(s) for multicycle replication in cultured cells. However, the potential role of proteases in the infection process remains unclear. In order to explore this, we used two different approaches: we infected either Vero cells in the presence of trypsin or Vero cells that constitutively express the membrane-associated protease TMPRSS2 (Vero/TMPRSS2 cells). We found that PEDV infection was enhanced, and viruses were efficiently released into the culture fluid, from Vero cells infected in the presence of protease, while in cells without protease, the virus grew, but its release into the culture fluid was strongly hampered. Cell-to-cell fusion of PEDV-infected cells and cleavage of the spike (S) protein were observed in cells with protease. When infected Vero cells were cultured for 3 days in the absence of trypsin but were then treated transiently with trypsin, infectious viruses were immediately released from infected cells. In addition, treatment of infected Vero/TMPRSS2 cells with the protease inhibitor leupeptin strongly blocked the release of virus into the culture fluid. Under electron microscopy, PEDV-infected Vero cells, as well as PEDV-infected Vero/TMPRSS2 cells treated with leupeptin, retained huge clusters of virions on their surfaces, while such clusters were rarely seen in the presence of trypsin and the absence of leupeptin in Vero and Vero/TMPRSS2 cells, respectively. Thus, the present study indicates that proteases play an important role in the release of PEDV virions clustered on cells after replication occurs. This unique observation in coronavirus infection suggests that the actions of proteases are reminiscent of that of the influenza virus neuraminidase protein. PMID:21613395

Shirato, Kazuya; Matsuyama, Shutoku; Ujike, Makoto; Taguchi, Fumihiro

2011-01-01

129

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells  

PubMed Central

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on collagen-coated microcarrier beads, as well as in HeLa cells grown in tissue culture flasks. Microscopy analysis revealed no difference in chlamydial attachment/entry patterns or in inclusion development throughout the developmental cycle between cell lines. Very comparable growth curves in both cell lines were also found using real-time PCR analysis, with increases in chlamydial DNA content of 400–500-fold between 2 and 36 h post-inoculation. Similar progeny yields with comparable infectivity were recovered from HEC-1B and HeLa cell bead cultures, and no difference in chlamydial growth was found in polarized vs. non-polarized HeLa cells. In conclusion, unlike other C. trachomatis strains such as urogenital serovar E, invasive serovar L2 grows equally well in physiologically different endometrial and endocervical environments, regardless of the host cell polarization state. PMID:18396437

Dessus-Babus, Sophie; Moore, Cheryl G.; Whittimore, Judy D.; Wyrick, Priscilla B.

2008-01-01

130

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

NASA Astrophysics Data System (ADS)

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.

Nedukha, Olena

131

Effect of vaccination schedule on immune response of Macaca mulatta to cell culture-grown Rocky Mountain spotted fever vaccine.  

PubMed Central

The effect of vaccination schedule on the immune response of Macaca mulatta to formalin-inactivated chicken embryo cell culture (CEC)-grown Rickettsia rickettsii vaccine was studied. Schedules consisted of inoculation on day 1 only, on days 1 and 15, on days 1 and 30, on days 1, 8, and 15, or on days 1, 15, and 45. Humoral antibody measured by microagglutination and indirect immunofluorescence and resistance to challenge with 10(4) plaque-forming units of yolk sac-grown R. rickettsii were assessed. Seroconversion was noted in all monkeys after the first dose of vaccine. A second dose administered 8 or 15 days after the primary infection, or a third given 7 or 30 days after the second, produced no long-term effect on antibody titer. Only monkeys given two doses of vaccine at a 30-day interval showed an increase in antibody titer during the period before challenge. Vaccination with one, two, or three doses of CEC vaccine prevented development of rash and rickettsemia after challenge. The two-dose schedules appeared to induce the highest degree of resistance to challenge, as indicated by unaltered hematological parameters and body temperature in monkeys. The one- and three-dose schedules were somewhat less effective, in that some challenged monkeys within each group displayed febrile and leukocyte responses associated with Rocky Mountain spotted fever infection. Our data suggest that administration of two doses of CEC vaccine at 15- or 30-day intervals is the immunization schedule of choice. PMID:823173

Sammons, L S; Kenyon, R H; Pedersen, C E

1976-01-01

132

Hall Effect Studies of AlGaAs Grown by Liquid-Phase Epitaxy for Tandem Solar Cell Applications  

NASA Astrophysics Data System (ADS)

We report results from Hall effect studies on Al x Ga1- x As ( x = 0.23-0.24) with bandgap energies of 1.76 ± 0.01 eV grown by liquid-phase epitaxy (LPE). Room-temperature Hall measurements on unintentionally doped AlGaAs revealed p-type background doping for concentrations in the range 3.7-5.2 × 1016 cm-3. Sn, Te, Ge, and Zn-doped AlGaAs were also characterized to study the relationship between doping concentrations and the atomic fractions of the dopants in the melt. Temperature-dependent Hall measurements were performed to determine the activation energies of the four dopants. Deep donor levels (DX centers) were dominant for Sn-doped Al0.24Ga0.76As, but not for Te-doped Al0.24Ga0.76As. Comparison of the temperature-dependent Hall effect results for unintentionally and intentionally doped Al0.24Ga0.76As indicated that the impurity contributing to the p-type background doping had the same activation energy as Mg. We thus suggest a Te-doped emitter and an undoped or Ge-doped base to maximize the efficiency of Al x Ga1- x As ( x ˜ 0.23) solar cells grown by LPE.

Zhao, Xin; Montgomery, Kyle H.; Woodall, Jerry M.

2014-11-01

133

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

PubMed

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. PMID:11543390

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

2000-01-01

134

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

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

135

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

NASA Astrophysics Data System (ADS)

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 TNF? 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.

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

2014-03-01

136

MDR-1-overexpression in HT 29 colon cancer cells grown in SCID mice.  

PubMed

The multidrug-resistance 1 (MDR-1) P-glycoprotein (Pgp) is a transmembrane transporter system, which actively pumps cytotoxic drugs out of the cell. MDR-1 acquired in vitro differs from MDR-1 acquired in vivo, but has important consequences on the cellular phenotype and metastatic behavior. Here we report that the human colonic cancer cell line HT29 (MDR-1 negative) is more malignant than its MDR-1 overexpressing variant (HT29 MDR-1 positive). HT29 MDR-1 negative cells produce undifferentiated signet ring carcinomas when implanted subcutaneously into SCID mice, while HT29 MDR-1 positive cells form tumors with tubular structures, but without signet ring cells. Immunohistochemical proliferation marker analysis revealed that the MDR-1 positive cells proliferate much more slowly than the MDR-1 negative cells. MDR-1 overexpression results in a less differentiated phenotype at the cellular level (absence of mucin producing cells) but in a more differentiated phenotype at the tissue level (tubule formation). In addition, lectin binding patterns including that of Helix pomatia agglutinin (HPA), an indicator of metastatic potential, differed between the two cell lines. HT29 MDR-1 positive cells had less HPA binding sites than HT29 MDR-1 negative counterparts and metastasized less frequently in SCID mice. As slow proliferation, low degree of differentiation and multidrug-resistance is a hallmark of cancer stem cells and all were present in MDR-1 positive tumors, it is attractive to speculate that they represent a stem cell rich tumor. As shown by global gene expression analyses, genes involved, e.g. in cell adhesion, glycosylation and signal transduction, were deregulated in MDR-1 positive tumors compared to MDR-negative tumors. Overexpression of E-cadherin and carcinoembryonic antigen-related cell adhesion molecules 1 (CEACAM1) may provide clues to the mechanisms responsible for the reduced metastatic potential of MDR-1 overexpressing tumors. Since drug treatment shifted the cells towards a less metastatic phenotype in this in vivo model, it seems conceivable to achieve this using drug treatment also in a clinical situation. PMID:22154301

Schumacher, Udo; Nehmann, Nina; Adam, Elizabeth; Mukthar, Dhia; Slotki, Itzchak N; Horny, Hans-Peter; Flens, Marcel J; Schlegelberger, Brigitte; Steinemann, Doris

2012-10-01

137

Photosynthetic carbon metabolism in photoautotrophic cell suspension cultures grown at low and high CO sub 2  

SciTech Connect

Photosynthetic carbon metabolism was characterized in four photoautotrophic cell suspension cultures. There was no apparent difference between two soybeans (Glycine max) and one cotton (Gossypium hirsutum) cell line which required 5% CO{sub 2} for growth, and a unique cotton cell line that grows at ambient CO{sub 2} (660 microliters per liter). Photosynthetic characteristics in all four lines were more like C{sub 3} mesophyll leaf cells than the cell suspension cultures previously studied. The pattern of {sup 14}C-labeling reflected the high ratio of ribulosebisphosphate carboxylase to phosphoenolpyruvate carboxylase activity and showed that CO{sub 2} fixation occurred primarily by the C{sub 3} pathway. Photorespiration occurred at 330 microliters per liter CO{sub 2}, 21% O{sub 2} as indicated by the synthesis of high levels of {sup 14}C-labeled glycine and serine in a pulse-chase experiment and by oxygen inhibition of CO{sub 2} fixation. Short-term CO{sub 2} fixation in the presence and absence of carbonic anhydrase showed CO{sub 2}, not HCO{sub 3}{sup {minus}}, to be the main source of inorganic carbon taken up by the low CO{sub 2}-requiring cotton cells. The cells did not have a CO{sub 2}-concentrating mechanism as indicated by silicone oil centrifugation experiments. Carbonic anhydrase was absent in the low CO{sub 2}-requiring cotton cells, present in the high CO{sub 2}-requiring soybean cell lines, and absent in other high CO{sub 2} cell lines examined. Thus, the presence of carbonic anhydrase is not an essential requirement for photoautotrophy in cell suspension cultures which grow at either high or low CO{sub 2} concentrations.

Roeske, C.A.; Widholm, J.M. (Univ. of Illinois at Urbana-Champaign (USA)); Ogren, W.L. (Department of Agriculture, Urbana, IL (USA))

1989-12-01

138

Identification of an anticancer compound against HT-29 cells from Phellinus linteus grown on germinated brown rice  

PubMed Central

Objective To isolate and identify the anticancer compound against proliferation of human colon cancer cells from ethyl acetate (EtOAC) extract of Phellinus linteus grown on germinated brown rice (PB). Methods EtOAC extract of PB was partitioned with n-hexane, EtOAC, and water-saturated n-butanol. Anticancer compound of n-hexane layer was isolated and identified by HPLC and NMR, respectively. Cytotoxicity against HT-29 cells was tested by SRB assay. Results The n-hexane layer obtained after solvent fractionation of PB EtOAC extracts showed a potent anticancer activity against the HT-29 cell line. Atractylenolide I, a eudesmane-type sesquiterpene lactone, a major anticancer substance of PB, was isolated from the n-hexane layer by silica gel column chromatography and preparative-HPLC. This structure was elucidated by one- and two-dimensional NMR spectroscopic data. Atractylenolide I has not been reported in mushrooms or rice as of yet. The isolated compound dose-dependently inhibited the growth of HT-29 human colon cancer cells. Conclusions Atractylenolide I might contribute to the anticancer effect of PB. PMID:24075343

Jeon, Tae-Il; Jung, Chang-Hwa; Cho, Jeong-Yong; Park, Dong Ki; Moon, Jae-Hak

2013-01-01

139

An Easy-To-Handle Microfluidic Device Suitable for Immunohistochemical Procedures in Mammalian Cells Grown Under Flow Conditions  

PubMed Central

Microfluidics, the technology that manipulates small amount of fluids in microscale complex devices, has undergone a remarkable development during the last decade, by targeting a significant range of applications, including biological tests and single-cell analysis, and by displaying many advantages such as reduced reagent consumption, decreased costs and faster analysis. Furthermore, the introduction of microfluidic tools has revolutionized the study of vascular functions, because the controlled three-dimensional environment and the continuous perfusion provided by the microdevice allow simulating the physiological characteristics of the circulatory system. Researchers interested in the study of vascular physiology, however, are often hampered by the difficulty in handling reduced number of cells after growth in these devices. This work shows how to apply different protocols commonly used in biology, such as the immunofluorescence technique, to cells grown in reversibly-bound microfluidic devices, obtaining results comparable to those retrieved under static conditions in multiwells. In this way, we are able to combine the advantages of microfluidic, i.e., application of continuous flow and shear stress, with classical protocols for the study of endothelial cells. PMID:24998924

Fede, C.; Fortunati, I.; Petrelli, L.; Guidolin, D.; De Caro, R.; Ferrante, C.; Albertin, G.

2014-01-01

140

Polymer electrolyte fuel cell electrodes grown by vapor deposition techniques Pascal Brault*  

E-print Network

. Especially, one can mention the use of carbon aerogel, that readily provides new carbon supports for fuel fuel cell performances, e.g. power density and catalyst activity. Keywords: fuel cell, electrode, PVD, CVD, thin film,catalyst, PEMFC hal-00688827,version1-18Apr2012 Author manuscript, published

Paris-Sud XI, Université de

141

Advanced APCVD-processes for high-temperature grown crystalline silicon thin film solar cells.  

PubMed

Crystalline silicon thin film (cSiTF) solar cells based on the epitaxial wafer-equivalent (EpiWE) concept combine advantages of wafer-based and thin film silicon solar cells. In this paper two processes beyond the standard process sequence for cSiTF cell fabrication are described. The first provides an alternative to wet chemical saw damage removal by chemical vapor etching (CVE) with hydrogen chloride in-situ prior to epitaxial deposition. This application decreases the number of process and handling steps. Solar cells fabricated with different etching processes achieved efficiencies up to 14.7%. 1300 degrees C etching temperature led to better cell results than 1200 degrees C. The second investigated process aims for an improvement of cell efficiency by implementation of a reflecting interlayer between substrate and active solar cell. Some characteristics of epitaxial lateral overgrowth (ELO) of a patterned silicon dioxide film in a lab-type reactor constructed at Fraunhofer ISE are described and first solar cell results are presented. PMID:22097550

Driessen, Marion; Merkel, Benjamin; Reber, Stefan

2011-09-01

142

Isolation of vero cytotoxin-producing Escherichia coli O157 from wild birds.  

PubMed

In a survey of wild birds (mainly gulls), 0.9% of the bacterial isolates from faecal samples at an urban landfill site and 2.9% of bacterial isolates from faecal samples on intertidal sediments in Morecambe Bay were Vero cytotoxin-producing Escherichia coli O157. Isolation procedures employing commonly used cultural methods were hindered by the selection of a large number of false positives. The only procedure which resulted in the isolation of E. coli O157 from bird faecal samples was: enrichment (18 h) in a selective tryptone soya broth followed by filtration using hydrophobic grid membranes and growth on Chromagar O157. The majority of isolates selected as potential E. coli O157 by characteristic growth on Chromagar O157 could be eliminated by subsequent growth on CT-SMAC or CR-SMAC. This second identification (characterization) stage reduced the number of potential E. coli O157 requiring further confirmation by typing methods (serotype and Vero cytotoxin) by more than 70%. PMID:12455905

Wallace, J S; Cheasty, T; Jones, K

1997-03-01

143

Heteroepitaxial film silicon solar cell grown on Ni-W foils  

SciTech Connect

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).

Wee, Sung Hun [ORNL; Cantoni, Claudia [ORNL; Fanning, Thomas [Ampulse Corporation; Teplin, Charles [National Renewable Energy Laboratory (NREL); Bogorin, Daniela Florentina [ORNL; Bornstein, Jon [Ampulse Corporation; Bowers, Karen [Ampulse Corporation; Schroeter, [Ampulse Corporation; Hasoon, Falah [National Renewable Energy Laboratory (NREL); Branz, Howard [National Renewable Energy Laboratory (NREL); Paranthaman, Mariappan Parans [ORNL; Goyal, Amit [ORNL

2013-01-01

144

DMEM. H1299 cells were a gift from J. Chen and were grown in RPMI. All transfections were carried out using Lipofectamine 2000 (Invitrogen), Oligofectamine (Invitrogen) or  

E-print Network

DMEM. H1299 cells were a gift from J. Chen and were grown in RPMI. All transfections were carried of p53, Saos-2 cells were transfected with increasing amounts of Flag­COP1 or Flag­COP1DRING with 250 ng pcDNA3.1þp53, and U2-OS cells were transfected with or without increasing amounts (0.5, 1 and 2 mg

Babu, M. Madan

145

Photovoltaic characteristics of n+pp+ InP solar cells grown by OMVPE  

Microsoft Academic Search

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

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

1990-01-01

146

Stable release of BDNF from the fibroblast cell line NIH3T3 grown on silicone elastomers enhances survival of spiral ganglion cells in vitro and in vivo.  

PubMed

The treatment of choice for profound sensorineural hearing loss (SNHL) is direct electrical stimulation of spiral ganglion cells (SGC) via a cochlear implant (CI). The number and excitability of SGC seem to be critical for the success that can be achieved via CI treatment. However, SNHL is associated with degeneration of SGC. Long-term drug delivery to the inner ear for improving SGC survival may be achieved by functionalisation of CI electrodes with cells providing growth factors. Therefore, the capacity of brain-derived neurotrophic factor (BDNF)-secreting NIH3T3 cells grown on cylindrically shaped silicone elastomers (SE) to exert local and sustained neuroprotective effects was assessed in vitro and in vivo. An in vitro model to investigate adhesion and cell growth of lentivirally modified NIH3T3 cells synthesising BDNF on SE was established. The bioactivity of BDNF was characterised by co-cultivation of SGC with cell-coated SE. In addition, cell-coated SE were implanted into deafened guinea pigs. The recombinant NIH3T3 cells proliferated on silicone surfaces during 14 days of cultivation and expressed significantly increasing BDNF levels. Enhanced survival rates and neurite outgrowth of SGC demonstrated the bioactivity of BDNF in vitro. Implantation of SE with adhering BDNF-secreting NIH3T3 cells into the cochleae of systemically deafened guinea pigs induced a significant increase in SGC survival in comparison to SE without cell coating. Our data demonstrate a novel approach of cell-based long-term drug delivery to support SGC survival in vitro and in vivo. This therapeutic strategy--once transferred to cells suitable for clinical application--may improve CI performance. PMID:22564255

Warnecke, Athanasia; Sasse, Susanne; Wenzel, Gentiana I; Hoffmann, Andrea; Gross, Gerhard; Paasche, Gerrit; Scheper, Verena; Reich, Uta; Esser, Karl-Heinz; Lenarz, Thomas; Stöver, Timo; Wissel, Kirsten

2012-07-01

147

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

148

Space concentrator solar cells based on multilayer LPE grown AlGaAs/GaAs heterostructure  

NASA Technical Reports Server (NTRS)

The high efficiency solar cells based on multilayer AlGaAs/GaAs heterostructures, prepared by low temperature liquid phase epitaxy (LPE), were developed and tested. An investigation of the low temperature LPE process for the crystallization of AlGaAs heterostructures of as high as 24.0 to 24.7 percent under AMO conditions at concentration ratios of 20 to 100x, were reached. Developed solar cells show substantial radiation resistance to the damage induced by 3.75 MeV electrons.

Khvostikov, V. P.; Larionov, V. R.; Paleeva, E. V.; Sorokina, S. V.; Chosta, O. I.; Shvarts, M. Z.; Zimogorova, N. S.

1995-01-01

149

High efficiency GaAs-Ge tandem solar cells grown by MOCVD  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

150

Identity, fate and potential of cells grown as neurospheres: species matters.  

PubMed

It is commonly accepted that adult neurogenesis and gliogenesis follow the same principles through the mammalian class. However, it has been reported that neurogenesis might differ between species, even from the same order, like in rodents. Currently, it is not known if neural stem/progenitor cells (NSPCs) from various species differ in their cell identity and potential. NSPCs can be expanded ex vivo as neurospheres (NSph), a model widely used to study neurogenesis in vitro. Here we demonstrate that rat (r) and mouse (m) NSph display different cell identities, differentiation fate, electrophysiological function and tumorigenic potential. Adult rNSph consist mainly of oligodendroglial progenitors (OPCs), which after repeated passaging proliferate independent of mitogens, whereas adult mNSph show astroglial precursor-like characteristics and retain their mitogen dependency. Most of the cells in rNSph express OPC markers and spontaneously differentiate into oligodendrocytes after growth factor withdrawal. Electrophysiological analysis confirmed OPC characteristics. mNSph have different electrophysiological properties, they express astrocyte precursor markers and spontaneously differentiate primarily into astrocytes. Furthermore, rNSph have the potential to differentiate into oligodendrocytes and astrocytes, whereas mNSph are restricted to the astrocytic lineage. The phenotypic differences between rNSph and mNSph were not due to a distinct response to species specific derived growth factors and are probably not caused by autocrine mechanisms. Our findings suggest that NSph derived from adult rat and mouse brains display different cell identities. Thus, results urge for caution when data derived from NSph are extrapolated to other species or to the in vivo situation, especially when aimed towards the clinical use of human NSph. PMID:21431886

Steffenhagen, Carolin; Kraus, Sabrina; Dechant, Franz-Xaver; Kandasamy, Mahesh; Lehner, Bernadette; Poehler, Anne-Maria; Furtner, Tanja; Siebzehnrubl, Florian A; Couillard-Despres, Sebastien; Strauss, Olaf; Aigner, Ludwig; Rivera, Francisco J

2011-11-01

151

Heteroepitaxial Film Silicon Solar Cell Grown on Ni-W Foils  

SciTech Connect

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.

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

152

Induction of IL8 expression by Cordyceps militaris grown on germinated soybeans through lipid rafts formation and signaling pathways via ERK and JNK in A549 cells  

Microsoft Academic Search

Aim of the studyIn order to elucidate immunoregulatory mechanisms of Cordyceps militaris, a methanol extract of Cordyceps militaris grown on germinated soybeans was prepared and its immunoregulatory effect in the human lung epithelial cells was investigated by examining its ability to induce IL-8 expression.

Ji Young Han; Jintaek Im; Jung Nam Choi; Choong Hwan Lee; Hye Jin Park; Dong Ki Park; Cheol-Heui Yun; Seung Hyun Han

2010-01-01

153

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)

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 otherwise die or be rendered reproductively inactive in 2-D culture.

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

2011-01-01

154

Biochemical studies on sulfate-reducing bacteria. XIV. Enzyme levels of adenylylsulfate reductase, inorganic pyrophosphatase, sulfite reductase, hydrogenase, and adenosine triphosphatase in cells grown on sulfate, sulfite, and thiosulfate.  

PubMed

Sulfate-reducing bacteria, Desulfovibrio vulgaris, strain Miyazaki, were grown on either sulfate, sulfite, or thiosulfate as the terminal electron acceptor. Better growth was observed on sulfite and less growth on thiosulfate than on sulfate. Enzyme levels of adenylylsulfate (APS) reductase [EC 1.8.99.2], reductant-activated inorganic pyrophosphatase [EC 3.6.1.1], sulfite reductase [EC 1.8.99.1] (desulfoviridin), hydrogenase [EC 1.12.2.1], and Mg2+-activated ATPase [EC 3.6.1.3] were compared in crude extracts of these cells at various stages of growth. 1) The specific activity of APS reductase in sulfite-grown cells was only one-fourth that in sulfate-grown cells throughout growth. Thiosulfate-grown cells had an activity intermediate between those of sulfate- and sulfite-grown cells. 2) Cells grown on sulfite had lower specific activity of reductant-activated inorganic pyrophosphatase than cells grown on sulfate or thiosulfate. 3) The specific activity of sulfite reductase (desulfoviridin) was highest in sulfite-grown cells. The sulfite medium gave the enzyme in high yield as well as with high specific activity. 4) The specific activities of hydrogenase and Mg2+-ATPase were not significantly altered by electron acceptors in the growth medium. PMID:175050

Kobayashi, K; Morisawa, Y; Ishituka, T; Ishimoto, M

1975-11-01

155

Energy Sources for HCO3? and CO2 Transport in Air-Grown Cells of Synechococcus UTEX 6251  

PubMed Central

Light-dependent inorganic C (Ci) transport and accumulation in air-grown cells of Synechococcus UTEX 625 were examined with a mass spectrometer in the presence of inhibitors or artificial electron acceptors of photosynthesis in an attempt to drive CO2 or HCO3? uptake separately by the cyclic or linear electron transport chains. In the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the cells were able to accumulate an intracellular Ci pool of 20 mm, even though CO2 fixation was completely inhibited, indicating that cyclic electron flow was involved in the Ci-concentrating mechanism. When 200 ?m N,N-dimethyl-p-nitrosoaniline was used to drain electrons from ferredoxin, a similar Ci accumulation was observed, suggesting that linear electron flow could support the transport of Ci. When carbonic anhydrase was not present, initial CO2 uptake was greatly reduced and the extracellular [CO2] eventually increased to a level higher than equilibrium, strongly suggesting that CO2 transport was inhibited and that Ci accumulation was the result of active HCO3? transport. With 3-(3,4-dichlorophenyl)-1,1-dimethylurea-treated cells, Ci transport and accumulation were inhibited by inhibitors of CO2 transport, such as COS and Na2S, whereas Li+, an HCO3?-transport inhibitor, had little effect. In the presence of N,N-dimethyl-p-nitrosoaniline, Ci transport and accumulation were not inhibited by COS and Na2S but were inhibited by Li+. These results suggest that CO2 transport is supported by cyclic electron transport and that HCO3? transport is supported by linear electron transport. PMID:9501145

Li, Qinglin; Canvin, David T.

1998-01-01

156

Energy sources for HCO3- and CO2 transport in air-grown cells of synechococcus UTEX 625  

PubMed

Light-dependent inorganic C (Ci) transport and accumulation in air-grown cells of Synechococcus UTEX 625 were examined with a mass spectrometer in the presence of inhibitors or artificial electron acceptors of photosynthesis in an attempt to drive CO2 or HCO3- uptake separately by the cyclic or linear electron transport chains. In the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the cells were able to accumulate an intracellular Ci pool of 20 mm, even though CO2 fixation was completely inhibited, indicating that cyclic electron flow was involved in the Ci-concentrating mechanism. When 200 m N,N-dimethyl-p-nitrosoaniline was used to drain electrons from ferredoxin, a similar Ci accumulation was observed, suggesting that linear electron flow could support the transport of Ci. When carbonic anhydrase was not present, initial CO2 uptake was greatly reduced and the extracellular [CO2] eventually increased to a level higher than equilibrium, strongly suggesting that CO2 transport was inhibited and that Ci accumulation was the result of active HCO3- transport. With 3-(3,4-dichlorophenyl)-1, 1-dimethylurea-treated cells, Ci transport and accumulation were inhibited by inhibitors of CO2 transport, such as COS and Na2S, whereas Li+, an HCO3--transport inhibitor, had little effect. In the presence of N,N-dimethyl-p-nitrosoaniline, Ci transport and accumulation were not inhibited by COS and Na2S but were inhibited by Li+. These results suggest that CO2 transport is supported by cyclic electron transport and that HCO3- transport is supported by linear electron transport. PMID:9501145

Li; Canvin

1998-03-01

157

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

PubMed Central

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 that of Pseudomonas AM1 growing on methanol. PMID:5435492

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

1970-01-01

158

Efficient large-scale generation of functional hepatocytes from mouse embryonic stem cells grown in a rotating bioreactor with exogenous growth factors and hormones  

PubMed Central

Introduction Embryonic stem (ES) cells are considered a potentially advantageous source of hepatocytes for both transplantation and the development of bioartificial livers. However, the efficient large-scale generation of functional hepatocytes from ES cells remains a major challenge, especially for those methods compatible with clinical applications. Methods In this study, we investigated whether a large number of functional hepatocytes can be differentiated from mouse ES (mES) cells using a simulated microgravity bioreactor. mES cells were cultured in a rotating bioreactor in the presence of exogenous growth factors and hormones to form embryoid bodies (EBs), which then differentiated into hepatocytes. Results During the rotating culture, most of the EB-derived cells gradually showed the histologic characteristics of normal hepatocytes. More specifically, the expression of hepatic genes and proteins was detected at a higher level in the differentiated cells from the bioreactor culture than in cells from a static culture. On further growing, the EBs on tissue-culture plates, most of the EB-derived cells were found to display the morphologic features of hepatocytes, as well as albumin synthesis. In addition, the EB-derived cells grown in the rotating bioreactor exhibited higher levels of liver-specific functions, such as glycogen storage, cytochrome P450 activity, low-density lipoprotein, and indocyanine green uptake, than did differentiated cells grown in static culture. When the EB-derived cells from day-14 EBs and the cells’ culture supernatant were injected into nude mice, the transplanted cells were engrafted into the recipient livers. Conclusions Large quantities of high-quality hepatocytes can be generated from mES cells in a rotating bioreactor via EB formation. This system may be useful in the large-scale generation of hepatocytes for both cell transplantation and the development of bioartificial livers. PMID:24294908

2013-01-01

159

Efficient hydrogen photoproduction by synchronously grown cells of a marine cyanobacterium, Synechococcus sp. Miami BG 043511, under high cell density conditions  

SciTech Connect

The capability of hydrogen photoproduction under high cell density conditions was examined using synchronously grown cells of nitrogen-fixing Synechococcus sp. Miami BG 043511. Optimum hydrogen yield was obtained when vessels contained 0.2 to 0.3 mg chlorophyll a in 3-mL cell suspension. During a 24-h incubation period, an initial phase of hydrogen and carbon dioxide production and a subsequent phase of carbon dioxide uptake and oxygen production were observed; hence, hydrogen and oxygen accumulated as major products after 24 h. After the initial 24-h incubation, as high as 7.4 and 3.7 mL of hydrogen and oxygen, respectively, accumulated in vessels with 22-mL gas phase. This indicated that the pressure in the flask increased to 1.5 atmosphere. Energy conversion efficiency based on photosynthetically active radiation (25) (W/m[sup 2]) was about 2.6%. However, increased pressure somehow reduced the duration of hydrogen production. Duration of hydrogen and oxygen production was prolonged by periodical gas replacement during incubation.

Kumazawa, S.; Mitsui, A. (Univ. of Miami, FL (United States). School of Marine and Atmospheric Science)

1994-09-20

160

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

PubMed Central

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

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

2012-01-01

161

Intragrain defects in polycrystalline silicon layers grown by aluminum-induced crystallization and epitaxy for thin-film solar cells  

NASA Astrophysics Data System (ADS)

Polycrystalline silicon (pc-Si) thin-films with a grain size in the range of 0.1-100 ?m grown on top of inexpensive substrates are economical materials for semiconductor devices such as transistors and solar cells and attract much attention nowadays. For pc-Si, grain size enlargement is thought to be an important parameter to improve material quality and therefore device performance. Aluminum-induced crystallization (AIC) of amorphous Si in combination with epitaxial growth allows achieving large-grained pc-Si layers on nonsilicon substrates. In this work, we made pc-Si layers with variable grain sizes by changing the crystallization temperature of the AIC process in order to see if larger grains indeed result in better solar cells. Solar cells based on these layers show a performance independent of the grain size. Defect etching and electron beam induced current (EBIC) measurements showed the presence of a high density of electrically active intragrain defects. We therefore consider them as the reason for the grain size independent device performance. Besides dislocations and stacking faults, also ?3 boundaries were electrically active as shown by combining electron backscattered diffraction with EBIC measurements. The electrical activity of the defects is probably triggered by impurity decoration. Plasma hydrogenation changed the electrical behavior of the defects, as seen by photoluminescence, but the defects were not completely passivated as shown by EBIC measurements. In order to reveal the origin of the defects, cross section transmission electron microscopy measurements were done showing that the intragrain defects are already present in the AIC seed layer and get copied into the epitaxial layer during epitaxial growth. The same types of intragrain defects were found in layers made on different substrates (alumina ceramic, glass ceramic, and oxidized silicon wafer) from which we conclude that intragrain defects are not related to the relatively rough alumina ceramic substrates often used in combination with high temperature epitaxy. Further improvement of the material quality, and hence device performance, is therefore not simply achieved by increasing the grain size, but the intragrain quality of the material also needs to be taken into account. For pc-Si layers based on AIC and epitaxial growth, the seed layer has a crucial impact on the intragrain defect formation.

Van Gestel, Dries; Gordon, Ivan; Bender, Hugo; Saurel, Damien; Vanacken, Johan; Beaucarne, Guy; Poortmans, Jef

2009-06-01

162

Photovoltaic electrical properties of aqueous grown ZnO antireflective nanostructure on Cu(In,Ga)Se? thin film solar cells.  

PubMed

A solution-grown subwavelength antireflection coating has been investigated for enhancing the photovoltaic efficiency of thin film solar cells. The 100-nm-height ZnO nanorods coating benefited the photocurrent of Cu(In,Ga)Se2 solar cells from 31.7 to 34.5 mA/cm2 via the decrease of surface light reflectance from 14.5% to 7.0%, contributed by the gradual refractive index profile between air and AZO window layer. The further reduction of surface reflectance to 2.3% in the case of 540-nm-height nanorods, yet, lowered the photocurrent to 29.5 mA/cm2, attributed to the decrease in transmittance. The absorption effect of hydrothermal grown ZnO nanorods was explored to optimize the antireflection function in enhancing photovoltaic performances. PMID:24921989

Wang, Yi-Chih; Lin, Bing-Yi; Liu, Po-Tsun; Shieh, Han-Ping D

2014-01-13

163

Characteristics of flexible indium tin oxide electrode grown by continuous roll-to-roll sputtering process for flexible organic solar cells  

Microsoft Academic Search

The preparation and characteristics of flexible indium tin oxide (ITO) electrodes grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll sputtering system for use in flexible organic solar cells are described. It was found that both electrical and optical properties of the flexible ITO electrode were critically dependent on the Ar\\/O2 flow ratio in the continuous roll-to-roll sputter

Kwang-Hyuk Choi; Jin-A Jeong; Jae-Wook Kang; Do-Guen Kim; Jong Kuk Kim; Seok-In Na; Dong-Yu Kim; Seok-Soon Kim; Han-Ki Kim

2009-01-01

164

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

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

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

2014-10-23

165

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

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.

Yokota, A.; Canvin, D.T.

1986-02-01

166

Bioremoval and recovery of Cd(II) by Pseudoalteromonas sp. SCSE709-6: Comparative study on growing and grown cells.  

PubMed

Comparison of the bioremoval and recovery of Cd(II) by growing and grown marine bacterium Pseudoalteromonas sp. SCSE709-6 was performed in batch systems. Bioremoval with growing cells (Sorption I) showed better performance at low Cd(II) concentrations, whereas bioremoval with grown cells (Sorption II) had significant advantages in both removal efficiency and time consumption at high Cd(II) concentrations. The optimal pH was higher for Sorption I than for Sorption II for achieving the maximum Cd(II) removal efficiency. Complete desorption was achieved using either Na2EDTA or HNO3 as eluent. Cd(II) adsorbed on grown cells had higher tendency to be desorbed. Na2EDTA was a preferable eluent for the recycling biomaterials, whereas HNO3 performed better for the final security disposal of sludge. For Sorption II, both Langmuir and Freundlich isotherms well explained the biosorption behavior, and the pseudo-second-order model better expressed biosorption and desorption kinetics. PMID:24565875

Zhou, Weizhi; Liu, Dongsheng; Zhang, Hai'ou; Kong, Wenqian; Zhang, Yuzhong

2014-08-01

167

A potential andrographolide analogue against the replication of herpes simplex virus type 1 in vero cells.  

PubMed

Andrographolide (AD), and 14-deoxyandrographolide (DAD) isolated from Andrographis paniculata Nees, Acanthaceae, and 3,19-isopropylideneandrographolide (IPAD), a semi-synthetic compound of AD, were examined for anti-HSV-1 activity in vitro. The inhibitory effects of these compounds on viral entry and replication steps were determined using pre- and post-infection assays, respectively. All the three compounds exhibited less than 50% inhibitory act against viral entry. In the post-infection, IPAD displayed absolute inhibition, whereas AD and DAD gave moderate activity. IPAD was selected to determine for the stage of anti-replication by time-of-addition and time-of-removal assays. From the time of removal assay, IPAD activity began after 4 h and completed at 16 h post infection which corresponded to the early genes expression. Its ability to inhibit HSV-1 was confirmed by polymerase chain reaction and the expression of viral glycoproteins C and D by western blot analysis. No viral enveloped glycoproteins D and C expressions were found. IPAD exhibited anti-HSV-1 replication relating to the early step of replication. Structure-activity relationships of andrographolide against HSV-1 was proposed, it is the first report of this ent-labdane diterpene. PMID:21486208

Seubsasana, Supawadee; Pientong, Chamsai; Ekalaksananan, Tipaya; Thongchai, Sasithorn; Aromdee, Chantana

2011-05-01

168

Reduction of the ochratoxin A-induced cytotoxicity in Vero cells by aspartame  

Microsoft Academic Search

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus as well as other moulds. This mycotoxin contaminates animal feed and human food and is nephrotoxic for all animal species\\u000a studied so far. OTA is immunosuppressive, genotoxic, teratogenic and carcinogenic. Recently lipid peroxidation induced by\\u000a OTA has been reported. OTA, a structural analogue of phenylalanine, inhibits protein synthesis by competition

I. Baudrimont; A. M. Betbeder; E. E. Creppy

1997-01-01

169

An in vitro model based on cell monolayers grown on the underside of large- pore filters in bicameral chambers for studying thyrocyte-lymphocyte interactions.  

PubMed

In the processes underlying thyroid autoimmunity, thyrocytes probably act as antigen-presenting cells exposing T-cell epitopes to intrathyroid lymphocytes. To study the interactions between lymphocytes and thyrocytes, which are arranged in a tight, polarized monolayer, we developed a new in vitro model based on human thyrocytes grown on the underside of a filter placed in a bicameral chamber. Thyrocytes from Graves' disease glands were plated onto the upper face of a 8-mum-pore polyethylene terephthalate culture insert filter placed in the inverted position and grown for 24 h before the insert was returned to the normal position for a week in the cell culture plate wells. Thyrocytes grown in the presence of thyroid stimulating hormone, forming a homogeneous monolayer on the underside of the filter, reached confluence after 8 days in vitro. The cells developed a transepithelial electrical resistance >1,000 Omega.cm(2), and the ZO-1 tight junction protein showed a junctional pattern of distribution. Thyrocytes showed a polarized pattern of thyroperoxidase and thyroid stimulating hormone receptor expression in the apical and basolateral positions, respectively. They were also found to aberrantly express DR class II human leukocyte antigen and an Fc immunoglobulin receptor (FcgammaRIIB2) in the basolateral and apical positions, respectively. Autologous intrathyroidal T lymphocytes cocultured for 24 h across the filter with the thyrocyte monolayer proliferated and remained in the upper chamber without any leakage occurring through the epithelial barrier, which makes this model particularly suitable for studying the cell-cell interactions involved in antigen processing. PMID:15329336

Estienne, Valérie; Brisbarre, Nadège; Blanchin, Stéphanie; Durand-Gorde, Josée-Martine; Carayon, Pierre; Ruf, Jean

2004-12-01

170

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)

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.

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

1984-01-01

171

GENERAL CELL STAINING PROTOCOL FOR FLOW CYTOMETRY 1) Except for cells grown in culture, cells obtained directly from tissues must first be resolved to  

E-print Network

: Phospate buffered Saline 1% normal sera of the animal for which 2% Bovine Serum Albumin the primary Calf Serum 0.1% Azide 3) Adjust concentration of cell suspension to at least 5 x 10 6 cells/ml. Cells

Oliver, Douglas L.

172

Interactions between the Promoter Regions of Nitrogenase Structural Genes (nifHDK2) and DNA-Binding Proteins from N2- and Ammonium-Grown Cells of the Archaeon Methanosarcina barkeri 227  

PubMed Central

Transcription initiation in Archaea (archaebacteria) resembles the eucaryotic process, having been shown to involve TATA box-like promoter regions as well as TATA-binding protein and TFIIB homologs. However, little is known about transcription regulation in archaea. We have previously demonstrated that transcripts of nifHDK2 genes, encoding Methanosarcina barkeri nitrogenase, are present in N2-grown cells but not in ammonium-grown cells, indicating that nif transcription is regulated by the nitrogen source. In this study, we detected proteins in M. barkeri cell extracts that bind specifically to DNA containing the putative promoter region of nifHDK2. No binding was found when the promoter region was deleted from the DNA. A competition assay showed that the methyl coenzyme M reductase (mcr) promoter region DNA and the nifH2 promoter region DNA competed for a common factor(s). There was no binding to the nifH2 promoter region by extracts of ammonium-grown cells, but there was binding by these extracts to promoter regions for mcr genes, which are presumably constitutively expressed. Interestingly, extracts of ammonium-grown cells inhibited binding to the nif promoter region by extracts of N2-grown cells. Fractionation of extracts of ammonium-grown cells with a heparin-Sepharose column resolved them into a fraction eluting at 0 M NaCl, which inhibited binding by extracts of N2-grown cells, and a fraction eluting at 0.5 to 0.75 M NaCl, which showed binding to the promoter region. These results are congruent with a model for regulation of nif gene expression in M. barkeri in which a substance present in ammonium-grown cells inhibits DNA binding by a transcription-associated protein or proteins. PMID:9573159

Chien, Yueh-tyng; Helmann, John D.; Zinder, Stephen H.

1998-01-01

173

Comparison of Vero-cytotoxin-encoding phages from Escherichia coli of human and bovine origin.  

PubMed

Phages encoding production of Vero cytotoxins VT1 or VT2 were isolated from strains of Escherichia coli of human and bovine origin. Two human strains of serotype O157: H7 produced both VT1 and VT2 and each carried two separate phages encoding either VT1 or VT2. The phages were morphologically similar to each other and to a VT2 phage previously isolated from a strain of serotype O157: H-; all had regular hexagonal heads and short tails. The phages had similar genome sizes and DNA hybridization and restriction enzyme digestion showed that the DNAs were very closely related. This contrasts with another report that one of the strains tested (933) released two clearly distinguishable phages separately encoding VT1 and VT2. The O157 phages differed from a VT1 phage isolated from a bovine E. coli strain belonging to serotype O26: H11 and from the reference VT1 phage isolated previously from a human strain, H19, of serotype O26: H11. The two O26 phages were morphologically similar with elongated heads and long tails. They had similar genome sizes and DNA hybridization indicated a high level of homology between them. Hybridization of an O157 phage DNA probe to DNA of the O26 phages, and vice versa, showed there was some cross-hybridization between the two types of phage. A phage from a bovine strain of serotype O29: H34 had a regular hexagonal head and short tail resembling those of the O157 phages. The DNA was distinguishable from that of all the other phages tested in restriction digest patterns but hybridized significantly to that of an O157 phage. Hybridization of the phage genomes with VT1 and VT2 gene probes showed that sequences encoding these toxins were highly conserved in the different phages from strains belonging to the three serogroups. PMID:2699332

Rietra, P J; Willshaw, G A; Smith, H R; Field, A M; Scotland, S M; Rowe, B

1989-08-01

174

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

SciTech Connect

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.

Boyer, L.L.

1996-06-01

175

Maintenance of milk protein gene expression in a subpopulation of 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinoma cells grown on attached collagen gels.  

PubMed

Milk protein gene expression was studied in cell subpopulations of 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinoma cells enriched or depleted for casein production grown on attached collagen gels. Culture of these cells in the presence of 10% fetal bovine serum, insulin (5 micrograms/ml), hydrocortisone (10 micrograms/ml), and prolactin (5 micrograms/ml) maintained alpha-, beta-, and gamma-casein and whey acidic protein mRNAs at levels identical to cells isolated from perphenazine-treated rats. Whey acidic protein mRNA levels in the tumor cells relative to the 14-d lactating gland were greater than those of the casein mRNAs. Withdrawal of prolactin from the casein-producing cells resulted in the loss of all four milk protein mRNAs. Subsequent addition of prolactin to the withdrawn cells caused a rapid accumulation of these mRNAs to prewithdrawal levels. Milk protein gene expression in this tumor cell subpopulation is modulated by prolactin (in the presence of insulin and hydrocortisone) in a similar manner to that observed in the normal mammary gland when these tumor cells are cultured on attached collagen gels. PMID:3928590

Johnson, M L; Levy, J; Rosen, J M

1985-08-01

176

A novel and facile approach to imaging nanoparticles transport across Transwell filter grown cell monolayer in real-time and in situ under confocal laser scanning microscopy.  

PubMed

Although the cellular endocytosis or uptake research using confocal laser scanning microscopy (CLSM) and Transwell inserts was frequently reported in experimental cell research and pharmaceutical research, there is little report on cellular transport process based on the same techniques. One of main reasons is that fluorescence of most fluorescent reagents could be clearly and definitely seen under CLSM only when they are internalized into and concentrated within cells. Here, Madin-Darby Canine Kidney (MDCK) cells and Coumarin 6 labeled nanoparticles (C6-NPs) was used as models, a new system was developed to image C6-NPs transport across Transwell filter grown cell monolayer by adding free cells into the basolateral medium and making the Transwell insert semi-permeable membrane visible under CLSM. The transport process could be clearly imaged in real-time and in situ, based on the visualization of Transwell membrane indicating the relative position of cells and nanoparticles, and the free cells in the basolateral medium serving as collector and indicator for the transported nanoparticles. The method was also applied in cell migration study. We believe that the novel approach developed here will be certainly useful not only in exploration of nanoparticle cellular transport mechanism, but also in other cell biological sciences based on CLSM and Transwell. PMID:22382319

Zhao, Shanshan; Yuan, Lan; Wang, Jiancheng; Zhang, Xuan; He, Zhonggui; Zhang, Qiang

2012-01-01

177

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)

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.

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

1982-01-01

178

Properties of Vero cytotoxin-producing Escherichia coli of human and animal origin belonging to serotypes other than O157:H7.  

PubMed Central

Eight non-O157:H7 Vero cytotoxin (VT)-producing Escherichia coli (VTEC) strains isolated from ill persons and nine bovine and lamb strains of serogroups matching the human strains, were characterized for various properties known to be associated with E. coli virulence. Five different serogroups were represented: O5, O55, O103, O111 and O153. The bovine and lamb strains produced VT1, while 3 human strains produced VT1, 3 produced VT2 and 2 were positive for both VT1 and VT2. The strains were non-haemolytic on horse blood agar, did not produce either heat stable toxin A (STA) or heat labile toxin (LT), and were noninvasive. The CVD419 probe which has been proposed to identify enterohaemorrhagic E. coli (EHEC) hybridized with all of the O5 and O103 strains, none of the O55 and O153 strains, and 3 of the 4 O111 strains. The strains carried several different sized plasmids and hybridization of Southern blots with the CVD419 probe identified plasmids ranging in size from 42 x 10(6) to 90 x 10(6). The strains did not hybridize with the enteroadherence factor (EAF) probe derived from an enteropathogenic strain and associated with the ability to give localized adherence to HEp-2 cells. Nevertheless five of the strains adhered in a localized pattern to HEp-2 cells and Intestine 407 cells. Adhesion to either HEp-2 or Intestine 407 cells did not correlate with hybridization with the CVD419 probe or haemagglutinating properties. Images Fig. 1 PMID:2673828

Dorn, C. R.; Scotland, S. M.; Smith, H. R.; Willshaw, G. A.; Rowe, B.

1989-01-01

179

Isolation and propagation of infectious bursal disease virus using the ovine kidney continuous cell line.  

PubMed

Twenty-six samples known to contain infectious bursal disease virus (IBDV) were examined by virus-isolation attempts on ovine kidney (OK) cell line, Vero cell line, and chicken embryo fibroblast (CEF) cultures. Virus was isolated from two of 26 samples, three of 26 samples, and three of 25 samples on OK, Vero, and CEF cultures, respectively. However, in contrast to IBDV replication in Vero and CEF cultures, isolated virus was unable to induce serially sustained cytopathic effects (CPE) during successive passages in the OK cell line, unless cell lysates were treated with chloroform between every other passage. The cytopathogenicity of the untreated virus passaged in OK cells was revived and maintained upon passage in Vero cells. An initial single passage of laboratory or field material in OK cells followed by further passages in Vero cells resulted in virus isolation from six of 26 samples, which was better virus recovery than when either cell line was used alone or when CEF cultures were used. Twenty of the 26 test samples were originally positive when examined by nucleic acid hybridization with radiolabeled IBDV cDNA, indicating that some of the samples that were negative upon virus isolation using OK and Vero cells may have contained inactivated virus. PMID:1320862

Kibenge, F S; McKenna, P K

1992-01-01

180

Identification of chikungunya virus interacting proteins in mammalian cells.  

PubMed

Identification and characterization of virus host interactions is an essential step for the development of novel antiviral strategies. Very few studies have been targeted towards identification of chikungunya virus (CHIKV) interacting host proteins. In current study, virus overlay protein binding assay (VOPBA) and matrix-assisted laser desorption/ ionization time of flight analysis (MALDI TOF/TOF) were employed for the identification of CHIKV binding proteins in mammalian cells. HSP70 and actin were identified as virus binding proteins in HEK-293T and Vero-E6 cells, whereas STAT-2 was identified as an additional protein in Vero-E6 cells. Pre-incubation with anti-HSP70 antibody and miRNA silencing of HSP70 significantly reduced the CHIKV production in HEK-293T and Vero-E6 cells at early time points. These results suggest that CHIKV exploits the housekeeping molecules such as actin, HSP70 and STAT-2 to establish infection in the mammalian cells. PMID:24845503

Paingankar, Mandar S; Arankalle, Vidya A

2014-06-01

181

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

SciTech Connect

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.

Robertson, E.J.; Leech, R.M. [Univ. of York, Heslington (United Kingdom)

1995-01-01

182

[Changes in the reproduction of tick-borne encephalitis virus in cell cultures].  

PubMed

The currently used tick-borne encephalitis virus vaccines are based on the inactivation of tick-borne encephalitis virus (TBEV) of Far Eastern or West European genetic types from the primary cultures of chick embryo fibroblasts. Since the WHO recommends that vaccines should be designed using continuous cell cultures rather than chick embryos as a substrate, this investigation has compared the infection of continuous monolayer SPEV, Vero E6, and vaccine line Vero (B) cell cultures with TBEV strains of the Siberian and Far Eastern genetic types dominating in the endemic regions of Russia. After cell infection with Far Eastern (Sofyin and 205 strains) or Siberian (Aina, 2530, 2689, and 2703 strains) TBEV genetic types, the viable TBEV titers reached 2.8 Ig CPD50 for Vero (B) cells, 5.5 Ig CPD50 for Vero E6 cells, and up to 9 Ig CPD50 for SPEV cells. The quantitative scores of TBEV E antigen in enzyme immunoassay (EIA) and genome equivalents by reverse-transcription polymerase chain reaction (PCR), followed by real-time PCR, permitted one to estimate as high as 108 virions in 1 ml of culture fluid, which corresponded to those of the microscopic observations of CPD for SPEV cells and substantially exceeded the values for Vero E6 cells, and for Vero (B) cells in particular. The data of TBEV strain titration, EIA, and realtime reverse-transcription PCR suggest that the Russian vaccine Vero (B) cell line defined as meeting the WHO requirements, as well as Vero E6 cells may be used to design tick-borne encephalitis vaccine. PMID:22834147

Morozova, O V; Grishechkin, A E; Bakhvalova, V N; Isaeva, E I; Podcherniaeva, R Ia

2012-01-01

183

High-efficiency solar cells on edge-defined film-fed grown (18.2%) and string ribbon (17.8%) silicon by rapid thermal processing  

NASA Astrophysics Data System (ADS)

Solar cell efficiencies of 18.2 and 17.8% were achieved on edge-defined film-fed grown and string ribbon multicrystalline silicon, respectively. Improved understanding and hydrogenation of defects in ribbon materials contributed to the significant increase in bulk lifetime from 1-5 ?s to as high as 90-100 ?s during cell processing. It was found that SiNx-induced defect hydrogenation in these ribbon materials takes place within one second at 740-750 °C. The bulk lifetime decreases at annealing temperatures above 750 °C or annealing times above one second due to the enhanced dissociation of the hydrogenated defects coupled with the decrease in hydrogen supply from the SiNx film deposited by plasma enhanced chemical vapor deposition.

Rohatgi, A.; Kim, D. S.; Nakayashiki, K.; Yelundur, V.; Rounsaville, B.

2004-01-01

184

Nucleolar transformation in plants grown on clinostats  

Microsoft Academic Search

Summary Cells of carrot calli (Daucus carota L.) grown on clinostats (simulated weightlessness) exhibit increases in nucleolar number and volume. In clinostat-grown whole barley plants (Hordeum vulgare L. cv. Steptoe), nucleoli in ~70% of root meristem and root cortical cells in the 1 mm root apex exhibit multiple nodulations after one day of growth. The nucleolar nodules (1.1 µm mean

J. Shen-Miller; R. R. Hinchman

1995-01-01

185

Establishment of a macrophagelike cell line derived from U-937, human histiocytic lymphoma, grown serum-free.  

PubMed

A human macrophagelike cell line which grows in serum-free medium was established from a histiocytic lymphoma cell line, U-937. U-937 cells failed to differentiate into macrophagelike cells in serum-free medium plus 12-O-tetradecanoyl phorbol 13-acetate (TPA). Fibronectin and albumin in serum were necessary for differentiation of U-937 cells into macrophagelike cells in enriched RDF medium supplemented with insulin, transferrin, ethanolamine, selenite, egg yolk lipoprotein (eRDF-ITESL medium). The established cell line exhibited several characteristic properties of macrophage such as nitroblue tetrazolium reduction, phagocytic and alpha-naphthylbutyrate-esterase activities, and tumor necrosis factor and interleukin 1 production. At present the cells have been continuously maintained in eRDF-ITESL medium through over 150 passages. PMID:2243057

Kong, Z L; Miwa, M; Murakami, H; Shinohara, K

1990-10-01

186

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. ...

187

Characterization of cell lines derived from hamster tumors induced with the BK virus.  

PubMed

Some of the properties of three continuous cell lines derived from BK virus-induced hamster tumors were examined. The cell lines had in vitro growth characteristics of transformed cells. Morphologically most of the cells were fibroblastic, but multinucleated giant cells were also common. Ultrastructurally all three cell lines displayed the usual features of cells grown in vitro. Marked variation in the nuclear size and shape as well as prominent nucleoli were characteristic to these cells. No viruses or virus-like particles were found. Virus isolation attempts by fusing the cells with Vero cells were negative, and no virion antigen was detected in these cells by immunofluorescence. T antigen similar to that of other papovaviruses was found in the cells. This antigen stained with sera from a number of hamsters carrying transplanted BK virus-induced tumors, and also with SV 40 T antisera. The antigen disappeared after 30 minutes at 56 degrees C. Cytogenetic analyses showed that the three cell lines were heteroploid with subtetraploid numbers of chromosomes. Chromosome abnormalities were also seen. All three cell lines induced sarcomatous tumors in adult hamsters after subcutaneous inoculation. PMID:176970

Sten, M; Tolonen, A; Pitko, V M; Nevalainen, T; Mäntyjärvi, R A

1976-01-01

188

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

SciTech Connect

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.

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

2009-01-01

189

Effects of the aspect ratio on the dye adsorption of ZnO nanorods grown by using a sonochemical method for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Well-aligned ZnO nanorods for the photoelectrode of dye-sensitized solar cells (DSSCs) were grown via a sonochemical method, and the effects of their aspect ratios on the dye adsorption in DSSCs were studied. The control of the aspect ratio of well-aligned ZnO nanorods was performed by tuning the mole concentration of zinc acetate dehydrate in the range of 0.04-0.06M. The dye amounts adsorbed in the ZnO nanorods were estimated from the UV-Visible absorbance by using the Beer-Lambert law. The efficiency of DSSCs with ZnO nanorods was measured to investigate the effects of the aspect ratio of the ZnO nanorods on the dye adsorption properties. A change in the aspect ratio of the ZnO nanorods was founded to yield a change in their dye adsorption ability, resulting in a change in the efficiency of the DSSCs.

Choi, Seok Cheol; Yun, Won Suk; Sohn, Sang Ho; Oh, Sang Jin

2012-11-01

190

Improved conversion efficiency of as-grown InGaN/GaN quantum-well solar cells for hybrid integration  

NASA Astrophysics Data System (ADS)

We report on the photovoltaic characteristics of solar cells based on 15 and 30 InxGa1-xN/GaN (x = 0.10 and 0.19) multiquantum wells (MQWs) grown on sapphire. Doubling the number of MQWs increases the peak external quantum efficiency by a factor of 2 for both In contents. Devices with 19% In, with a spectral cutoff at 465 nm, exhibit an open-circuit voltage of 1.7 V and a short-circuit current density of 3.00 mA/cm2 under 1 sun AM1.5G illumination, leading to a conversion efficiency of 2.00%, making them promising for hybrid integration with non-III-nitride photovoltaic devices.

Valdueza-Felip, Sirona; Mukhtarova, Anna; Grenet, Louis; Bougerol, Catherine; Durand, Christophe; Eymery, Joel; Monroy, Eva

2014-03-01

191

High external quantum efficiency and fill-factor InGaN/GaN heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy  

SciTech Connect

High external quantum efficiency (EQE) p-i-n heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy are presented. EQE values including optical losses are greater than 50% with fill-factors over 72% when illuminated with a 1 sun AM0 spectrum. Optical absorption measurements in conjunction with EQE measurements indicate an internal quantum efficiency greater than 90% for the InGaN absorbing layer. By adjusting the thickness of the top p-type GaN window contact layer, it is shown that the short-wavelength (<365 nm) quantum efficiency is limited by the minority carrier diffusion length in highly Mg-doped p-GaN.

Lang, J. R.; Hurni, C. A.; Cruz, S. C.; Matioli, E.; Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106 (United States); Neufeld, C. J.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

2011-03-28

192

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

193

Protein phosphorylations in poliovirus infected cells.  

PubMed

In vivo phosphorylation of proteins that are associated with polysomes of poliovirus-infected VERO (African green monkey kidney) and HeLa (Henrietta Lacks) cells differed from phosphorylations observed with uninfected cells that were fed fresh medium. With both types of cells infection stimulated phosphorylation of proteins with molecular weights of 40 000-41 000, 39 000, 34 000, 32 000, and 24 000. Similarities of phosphorylations in VERO and HeLa cells suggest that they are a specific consequence of infection and might serve a regulatory function during protein synthesis. PMID:6260321

James, L A; Tershak, D R

1981-01-01

194

SIMS Characterization of Amorphous Silicon Solar Cells Grown by Hot-Wire Chemical Vapor Deposition on Stainless Steel  

SciTech Connect

This paper is intended to be an overview of some of the challenges that must be overcome when characterizing amourphous-silicon solar cell devices by the secondary ion mass spectrometry (SIMS) technique.

Reedy, R. C.; Wang, Q.; Moutinho, H.; Iwaniczko, E.; Mahan, A. H.

2000-01-01

195

Morphological, Biological, and Biochemical Characteristics of Human Bladder Transitional Cell Carcinomas Grown in Tissue Culture and in Nude Mice1  

Microsoft Academic Search

The morphological, biological, biochemical, and karyotypic characteristics of four human bladder transitional cell carcinoma lines, SW-780, SW-800, SW-1738, and SW-1710, were investi gated. In tissue culture, each cell line presented a distinct phen- otypic expression. All but line SW-1710 grew when transplanted in the nude mouse. Light and electron microscopic studies showed morphological characteristics similar to the tumors of origin,

Aikaterini A. Kyriazis; Andreas P. Kyriazis; William B. McCombs; Ward D. Peterson

196

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

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

197

Comparison of initial feasibility of host cell lines for viral vaccine production.  

PubMed

In order to reduce the time required for the development and production of viral vaccines, host cell lines should be available as expression systems for production of viral vaccines against groups of viral pathogens. A selection of cell lines was compared for their initial feasibility as expression system for the replication of polioviruses, influenza A viruses and respiratory syncytial virus (wild type strain A2). Six adherent cell lines (Vero, HEK-293, MRC-5, CHO-K1, BHK-21 c13, MDCK) and six single cell suspension cell lines (CAP, AGE1.CR.HS, sCHO-K1, BHK-21 c13 2p, MDCK SFS) were studied for their ability to propagate viruses. First, maximum cell densities were determined. Second, virus receptor expression and polarization of the cell lines regarding receptor distribution of eight different viruses were monitored using flow cytometry and immunocytochemistry. Organization of the actin cytoskeleton was studied by transfection of the cells with Lifeact™, a construct coding for actin-EGFP. Finally, the ability to produce virus progeny of the viruses studied was assayed for each cell line. The results suggest that single cell suspension cell lines grown on serum free medium are the best candidates to serve as host cell lines for virus replication. PMID:23684847

Vlecken, Danielle H W; Pelgrim, Ralf P M; Ruminski, Slawomir; Bakker, Wilfried A M; van der Pol, Leo A

2013-10-01

198

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

NASA Technical Reports Server (NTRS)

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.

Gruener, R.; Hoeger, G.

1988-01-01

199

Potent Inhibitory Effect of ?-Tocopherol on Prostate Cancer Cells Cultured in Vitro and Grown As Xenograft Tumors in Vivo.  

PubMed

In the present study, the effects of ?-tocopherol (?-T) on growth and apoptosis of human prostate cancer cells were determined and compared with that of ?-tocopherol (?-T), a commonly used form of vitamin E. Treatment of human prostate cancer cells with ?-T resulted in strong growth inhibition and apoptosis stimulation, while the effects of ?-T were modest. The strong effects of ?-T on the cells were associated with suppression of androgen receptor (AR) activity and decreased level of prostate specific antigen (PSA) that is a downstream target of the AR signaling. In the in vivo study, we found that ?-T had a more potent inhibitory effect on the formation and growth of prostate xenograft tumors than that of ?-T. Moreover, ?-T inhibited proliferation and stimulated apoptosis in the tumors. The present study identified ?-T as a better form of vitamin E than ?-T for future clinical studies of prostate cancer prevention. PMID:25322450

Huang, Huarong; He, Yan; Cui, Xiao-Xing; Goodin, Susan; Wang, Hong; Du, Zhi Yun; Li, Dongli; Zhang, Kun; Tony Kong, Ah-Ng; DiPaola, Robert S; Yang, Chung S; Conney, Allan H; Zheng, Xi

2014-11-01

200

The electrophoretic softness of the surface of Staphylococcus epidermidis cells grown in a liquid medium and on a solid agar  

Microsoft Academic Search

Many Staphylococcus epidermidis strains possess capsule or slime layers and consequently the staphylococcal cell surface should be regarded as a soft, polyelectrolyte layer allowing electrophoretic fluid flow through a layer of fixed charges. The presence of such a soft layer decreases the energy barrier due to electrostatic repulsion in the interaction of the organisms with negatively charged substrata (Morisaki, H.,

Paskal J. M. Kiers; Rolf Bos; Henny C. van der Mei; Henk J. Busscher

201

Bioactive metabolite production and stress-related hormones in Devil’s claw cell suspension cultures grown in bioreactors  

Microsoft Academic Search

In a previous report, we showed that cell cultures of Harpagophytum procumbens, a South African plant with high medicinal value, accumulate high amounts of anti-inflammatory phenylethanoid glycosides\\u000a during cultivation in shake-flasks. The aim of the present study was to transfer the phenylethanoid biosynthetic process to\\u000a a 3-L stirred tank reactor and a 1-L glass-column bioreactor (operated with pulsed aeration). We

Milen Georgiev; Jutta Ludwig-Müller; Jost Weber; Nina Stancheva; Thomas Bley

2011-01-01

202

Comparison of MOVPE grown GaAs solar cells using different substrates and group-V precursors  

Microsoft Academic Search

We have investigated the influence of substrate type (GaAs vs. germanium) and of group-V precursor (AsH3 vs. TBAs) on the epitaxial quality of (In)(Al)GaAs layers. We evaluated these layers in terms of morphology, background contamination and doping characteristics. For final benchmarking of the individually optimised processes, we produced p-on-n single junction GaAs solar cells and compared their relative performance. This

J. Derluyn; K. Dessein; G. Flamand; Y. Mols; J. Poortmans; G. Borghs; I. Moerman

2003-01-01

203

Solar cells on low-resistivity boron-doped Czochralski-grown silicon with stabilized efficiencies of 20%  

Microsoft Academic Search

Recently, it was shown that the boron-oxygen complex responsible for the light-induced lifetime degradation in oxygen-rich boron-doped silicon can be permanently deactivated by illumination at elevated temperatures. Since the degradation is particularly harmful in low-resistivity Czochralski silicon (Cz-Si), we apply the deactivation procedure to a high-efficiency rear interdigitated single evaporation emitter wrap-through solar cell made on 1.4 Omega cm B-doped

Bianca Lim; Sonja Hermann; Karsten Bothe; Jan Schmidt; Rolf Brendel

2008-01-01

204

Reflectivity and topography of cells grown on glass-coverslips measured with phase-shifted laser feedback interference microscopy  

PubMed Central

In spite of the advantages associated with the molecular specificity of fluorescence imaging, there is still a significant need to augment these approaches with label-free imaging. Therefore, we have implemented a form of interference microscopy based upon phase-shifted, laser-feedback interferometry and developed an algorithm that can be used to separate the contribution of the elastically scattered light by sub-cellular structures from the reflection at the coverslip-buffer interface. The method offers an opportunity to probe protein aggregation, index of refraction variations and structure. We measure the topography and reflection from calibration spheres and from stress fibers and adhesions in both fixed and motile cells. Unlike the data acquired with reflection interference contrast microscopy, where the reflection from adhesions can appear dark, our approach demonstrates that these regions have high reflectivity. The data acquired from fixed and live cells show the presence of a dense actin layer located ? 100 nm above the coverslip interface. Finally, the measured dynamics of filopodia and the lamella in a live cell supports retrograde flow as the dominate mechanism responsible for filopodia retraction. PMID:21833378

At?lgan, Erdinc; Ovryn, Ben

2011-01-01

205

Antiallergic activity of novel isoflavone methyl-glycosides from Cordyceps militaris grown on germinated soybeans in antigen-stimulated mast cells.  

PubMed

Isoflavones are known to possess immunomodulating and antiallergic activities. Previously we identified novel isoflavone methyl-glycosides (daidzein 7-O-?-d-glucoside 4?-O-methylate (CDGM), glycitein 7-O-?-D-glucoside 4?-O-methylate (CGLM), genistein 7-O-?-D-glucoside 4?-O-methylate (CGNMI) and genistein 4'-O-?-D-glucoside 4?-O-methylate (CGNMII)) from Cordyceps militaris grown on germinated soybeans (GSC). The biological activity of novel isoflavone methyl-glycosides, however, remains unknown. In this study, CGNMII showed the strongest inhibition of degranulation. Additionally, the release of interleukin (IL)-4 and tumor necrosis factor (TNF)-? was decreased by CGNMII in antigen-stimulated RBL-2H3 cells. To elucidate the antiallergic mechanism of CGNMII, we examined whether it affected levels of signaling molecules responsible for degranulation. The levels of activated Lyn, Syk, PLC?1 and LAT proteins were reduced in CGNMII treated RBL-2H3 cells. CGNMII also inhibited the activation of AKT and ERK1/2 proteins. These results suggest that CGNMII might be used as a therapeutic agent for allergic diseases. PMID:22296272

Park, Dong Ki; Choi, Wahn Soo; Park, Hye-Jin

2012-03-01

206

Inorganic Carbon Accumulation Stimulates Linear Electron Flow to Artificial Electron Acceptors of Photosystem I in Air-Grown Cells of the Cyanobacterium Synechococcus UTEX 625.  

PubMed Central

The effect of inorganic carbon (Ci) transport and accumulation on photosynthetic electron transport was studied in air-grown cells of the cyanobacterium Synechococcus UTEX 625. When the cells were depleted of Ci, linear photosynthetic electron flow was almost completely inhibited in the presence of the photosystem I (PSI) acceptor N,N-dimethyl-p-nitrosoaniline (PNDA). The addition of Ci to these cells, in which CO2 fixation was inhibited with glycolaldehyde, greatly stimulated linear electron flow and resulted in increased levels of photochemical quenching and O2 evolution. In aerobic conditions substantial quenching resulted from methyl viologen (MV) addition and further quenching was not observed upon the addition of Ci. In anaerobic conditions MV addition did not result in quenching until Ci was added. Intracellular Ci pools were formed when MV was present in aerobic or anaerobic conditions or PNDA was present in aerobic conditions. There was no inhibitory effect of Ci depletion on electron flow to 2,6-dimethylbenzoquinone and oxidized diaminodurene, which accept electrons from photosystem II. The degree of stimulation of PNDA-dependent O2 evolution varied with the Ci concentration. The extracellular Ci, concentration required for a half-maximum rate (K1/2) was 3.8 [mu]M and the intracellular K1/2 was 1.4 mM for the stimulation of PNDA reduction. These values agreed closely with the K1/2 values of extracellular and intracellular Ci for O2 photoreduction. Linear electron flow to artificial electron acceptors of PSI was enhanced by intracellular Ci, which appeared to exert an effect on PSI or on the intersystem electron transport chain. PMID:12223770

Li, Q.; Canvin, D. T.

1997-01-01

207

Inorganic Carbon Accumulation Stimulates Linear Electron Flow to Artificial Electron Acceptors of Photosystem I in Air-Grown Cells of the Cyanobacterium Synechococcus UTEX 625.  

PubMed

The effect of inorganic carbon (Ci) transport and accumulation on photosynthetic electron transport was studied in air-grown cells of the cyanobacterium Synechococcus UTEX 625. When the cells were depleted of Ci, linear photosynthetic electron flow was almost completely inhibited in the presence of the photosystem I (PSI) acceptor N,N-dimethyl-p-nitrosoaniline (PNDA). The addition of Ci to these cells, in which CO2 fixation was inhibited with glycolaldehyde, greatly stimulated linear electron flow and resulted in increased levels of photochemical quenching and O2 evolution. In aerobic conditions substantial quenching resulted from methyl viologen (MV) addition and further quenching was not observed upon the addition of Ci. In anaerobic conditions MV addition did not result in quenching until Ci was added. Intracellular Ci pools were formed when MV was present in aerobic or anaerobic conditions or PNDA was present in aerobic conditions. There was no inhibitory effect of Ci depletion on electron flow to 2,6-dimethylbenzoquinone and oxidized diaminodurene, which accept electrons from photosystem II. The degree of stimulation of PNDA-dependent O2 evolution varied with the Ci concentration. The extracellular Ci, concentration required for a half-maximum rate (K1/2) was 3.8 [mu]M and the intracellular K1/2 was 1.4 mM for the stimulation of PNDA reduction. These values agreed closely with the K1/2 values of extracellular and intracellular Ci for O2 photoreduction. Linear electron flow to artificial electron acceptors of PSI was enhanced by intracellular Ci, which appeared to exert an effect on PSI or on the intersystem electron transport chain. PMID:12223770

Li, Q.; Canvin, D. T.

1997-08-01

208

InGaAs/GaAsP strain balanced multi-quantum wires grown on misoriented GaAs substrates for high efficiency solar cells  

NASA Astrophysics Data System (ADS)

Quantum wires (QWRs) form naturally when growing strain balanced InGaAs/GaAsP multi-quantum wells (MQW) on GaAs [100] 6° misoriented substrates under the usual growth conditions. The presence of wires instead of wells could have several unexpected consequences for the performance of the MQW solar cells, both positive and negative, that need to be assessed to achieve high conversion efficiencies. In this letter, we study QWR properties from the point of view of their performance as solar cells by means of transmission electron microscopy, time resolved photoluminescence and external quantum efficiency (EQE) using polarised light. We find that these QWRs have longer lifetimes than nominally identical QWs grown on exact [100] GaAs substrates, of up to 1 ?s, at any level of illumination. We attribute this effect to an asymmetric carrier escape from the nanostructures leading to a strong 1D-photo-charging, keeping electrons confined along the wire and holes in the barriers. In principle, these extended lifetimes could be exploited to enhance carrier collection and reduce dark current losses. Light absorption by these QWRs is 1.6 times weaker than QWs, as revealed by EQE measurements, which emphasises the need for more layers of nanostructures or the use light trapping techniques. Contrary to what we expected, QWR show very low absorption anisotropy, only 3.5%, which was the main drawback a priori of this nanostructure. We attribute this to a reduced lateral confinement inside the wires. These results encourage further study and optimization of QWRs for high efficiency solar cells.

Alonso-Álvarez, D.; Thomas, T.; Führer, M.; Hylton, N. P.; Ekins-Daukes, N. J.; Lackner, D.; Philipps, S. P.; Bett, A. W.; Sodabanlu, H.; Fujii, H.; Watanabe, K.; Sugiyama, M.; Nasi, L.; Campanini, M.

2014-08-01

209

Regulation of Cell Division, Biofilm Formation, and Virulence by FlhC in Escherichia coli O157:H7 Grown on Meat?†  

PubMed Central

To understand the continuous problems that Escherichia coli O157:H7 causes as food pathogen, this study assessed global gene regulation in bacteria growing on meat. Since FlhD/FlhC of E. coli K-12 laboratory strains was previously established as a major control point in transducing signals from the environment to several cellular processes, this study compared the expression pattern of an E. coli O157:H7 parent strain to that of its isogenic flhC mutant. This was done with bacteria that had been grown on meat. Microarray experiments revealed 287 putative targets of FlhC. Real-time PCR was performed as an alternative estimate of transcription and confirmed microarray data for 13 out of 15 genes tested (87%). The confirmed genes are representative of cellular functions, such as central metabolism, cell division, biofilm formation, and pathogenicity. An additional 13 genes from the same cellular functions that had not been hypothesized as being regulated by FlhC by the microarray experiment were tested with real-time PCR and also exhibited higher expression levels in the flhC mutant than in the parent strain. Physiological experiments were performed and confirmed that FlhC reduced the cell division rate, the amount of biofilm biomass, and pathogenicity in a chicken embryo lethality model. Altogether, this study provides valuable insight into the complex regulatory network of the pathogen that enables its survival under various environmental conditions. This information may be used to develop strategies that could be used to reduce the number of cells or pathogenicity of E. coli O157:H7 on meat by interfering with the signal transduction pathways. PMID:21498760

Sule, Preeti; Horne, Shelley M.; Logue, Catherine M.; Pruss, Birgit M.

2011-01-01

210

Vertically grown multiwalled carbon nanotube anode and nickel silicide integrated high performance microsized (1.25 ?L) microbial fuel cell.  

PubMed

Microbial fuel cells (MFCs) are an environmentally friendly method for water purification and self-sustained electricity generation using microorganisms. Microsized MFCs can also be a useful power source for lab-on-a-chip and similar integrated devices. We fabricated a 1.25 ?L microsized MFC containing an anode of vertically aligned, forest type multiwalled carbon nanotubes (MWCNTs) with a nickel silicide (NiSi) contact area that produced 197 mA/m(2) of current density and 392 mW/m(3) of power density. The MWCNTs increased the anode surface-to-volume ratio, which improved the ability of the microorganisms to couple and transfer electrons to the anode. The use of nickel silicide also helped to boost the output current by providing a low resistance contact area to more efficiently shuttle electrons from the anode out of the device. PMID:22268850

Mink, Justine E; Rojas, Jhonathan P; Logan, Bruce E; Hussain, Muhammad M

2012-02-01

211

Evaluation of defects generation in crystalline silicon ingot grown by cast technique with seed crystal for solar cells  

PubMed Central

Although crystalline silicon is widely used as substrate material for solar cell, many defects occur during crystal growth. In this study, the generation of crystalline defects in silicon substrates was evaluated. The distributions of small-angle grain boundaries were observed in substrates sliced parallel to the growth direction. Many precipitates consisting of light elemental impurities and small-angle grain boundaries were confirmed to propagate. The precipitates mainly consisted of Si, C, and N atoms. The small-angle grain boundaries were distributed after the precipitation density increased. Then, precipitates appeared at the small-angle grain boundaries. We consider that the origin of the small-angle grain boundaries was lattice mismatch and/or strain caused by the high-density precipitation. PMID:22536006

Tachibana, Tomihisa; Sameshima, Takashi; Kojima, Takuto; Arafune, Koji; Kakimoto, Koichi; Miyamura, Yoshiji; Harada, Hirofumi; Sekiguchi, Takashi; Ohshita, Yoshio; Ogura, Atsushi

2012-01-01

212

Effects of temperature and host cell type on the in vitro growth and development of Sarcocystis falcatula  

Microsoft Academic Search

The growth and development of Sarcocystis falcatula in four different cultured cell lines [vero cells, bovine turbinate (BT) cells, equine dermal (ED) cells, and human Hep-2 cells] inoculated with culture-derived merozoites are described. Parasite yields, viability, and plaque forming efficiency were used to compare the growth between different cell lines. Additionally, each cell line was tested at two temperatures of

Hany M. Elsheikha; Mahdi A. Saeed; Scott D. Fitzgerald; Alice J. Murphy; Linda S. Mansfield

2003-01-01

213

Cordyceps militaris Grown on Germinated Soybean Induces G2/M Cell Cycle Arrest through Downregulation of Cyclin B1 and Cdc25c in Human Colon Cancer HT-29 Cells  

PubMed Central

Cordyceps militaris (CM) is an insect-borne fungus that has been used in traditional Chinese medicine because of its wide range of pharmacological activities. In this paper, we studied CM grown on germinated soybean (GSC) and investigated the possible mechanisms underlying antiproliferative effect of GSC on HT-29 human colon cancer cells. In comparison with CM extracts and germinated soybean (GS) BuOH extracts, BuOH extracts of GSC showed remarkable inhibitory and antiproliferative effects on HT-29 colon cancer cells. After GSC treatment, HT-29 cells became smaller and irregular in shape. High G2/M phase cell populations were observed in the GSC-treated group. The levels of cyclin B1 and Cdc25 in the GSC-treated group were lower than those in the control group. These findings suggest that GSC BuOH extracts might act as an effective anti-proliferative agent by inducing G2/M cell cycle arrest in colon cancer cells. PMID:22474493

Mollah, Mohammad Lalmoddin; Park, Dong Ki; Park, Hye-Jin

2012-01-01

214

1 Rectangular Bunched Rutile TiO2 Nanorod Arrays Grown on Carbon 2 Fiber for Dye-Sensitized Solar Cells  

E-print Network

1 Rectangular Bunched Rutile TiO2 Nanorod Arrays Grown on Carbon 2 Fiber for Dye-Sensitized Solar a study of rectangular bunched 13 TiO2 nanorod (NR) arrays grown on carbon fibers (CFs) 14 from titanium by a "dissolve and grow" method. After a 15 corrosion process in a strong acid solution, every single nano- 16

Wang, Zhong L.

215

Facile fabrication of dye-sensitized solar cells utilizing carbon nanotubes grown over 2D hexagonal bimetallic ordered mesoporous materials  

NASA Astrophysics Data System (ADS)

High-surface area and well-ordered mesoporous Fe incorporated SBA-15 (Fe-SBA-15), Fe-Cr incorporated SBA-15 (Fe-Cr-SBA-15) and Cr incorporated SBA-15 (Cr-SBA-15) catalysts are synthesized following a controlled post synthesis grafting process. The activities of all the catalysts are tested systematically and quantitatively towards the production of carbon nanotubes (CNTs) by chemical vapour deposition. In order to obtain CNTs with high quality and quantity, the parameters like temperature, reaction time and gas flow rate are optimized. Under optimum conditions, the Fe-Cr-SBA-15 catalyst is produced with high yield and uniform diameter of CNTs. The transmission electron microscopy result reveals high purity and well-graphitized structure of CNTs. The synthesized CNTs are used as counter electrode material for dye-sensitized solar cells (DSSCs). The CNTs based counter electrode shows good chemical stability, lower charge-transfer resistance and higher electrocatalytic activity towards I3-/I- redox reaction than that of platinum (Pt) counter electrode. The energy conversion efficiency of the CNTs counter electrode based DSSCs reaches 8.86% under irradiation with a simulated solar light intensity of 100 mW cm-2. The results prove that CNTs are one of the suitable candidates for Pt free counter electrode for DSSCs.

Balamurugan, J.; Thangamuthu, R.; Pandurangan, A.; Jayachandran, M.

2013-03-01

216

Original article Apoptosis induction in BEFV-infected Vero and MDBK  

E-print Network

of BEFV. BEFV / apoptosis / caspase / Src / JNK 1. INTRODUCTION Bovine ephemeral fever (BEF), also known by the bovine ephemeral fever virus (BEFV), a member of the genus Ephemerovirus of the Rhabdoviridae family. BEF ephemeral fever virus (BEFV)-infected cultured cells could induce caspase-dependent apoptosis. This study

Paris-Sud XI, Université de

217

Metabolic Regulation of "Ca. Methylacidiphilum Fumariolicum" SolV Cells Grown Under Different Nitrogen and Oxygen Limitations  

PubMed Central

Aerobic methanotrophic bacteria can use methane as their sole energy source. The discovery of “Ca. Methylacidiphilum fumariolicum” strain SolV and other verrucomicrobial methanotrophs has revealed that the ability of bacteria to oxidize CH4 is much more diverse than has previously been assumed in terms of ecology, phylogeny, and physiology. A remarkable characteristic of the methane-oxidizing Verrucomicrobia is their extremely acidophilic phenotype, growing even below pH 1. In this study we used RNA-Seq to analyze the metabolic regulation of “Ca. M. fumariolicum” SolV cells growing at ?max in batch culture or under nitrogen fixing or oxygen limited conditions in chemostats, all at pH 2. The analysis showed that two of the three pmoCAB operons each encoding particulate methane monoxygenases were differentially expressed, probably regulated by the available oxygen. The hydrogen produced during N2 fixation is apparently recycled as demonstrated by the upregulation of the genes encoding a Ni/Fe-dependent hydrogenase. These hydrogenase genes were also upregulated under low oxygen conditions. Handling of nitrosative stress was shown by the expression of the nitric oxide reductase encoding genes norB and norC under all conditions tested, the upregulation of nitrite reductase nirK under oxygen limitation and of hydroxylamine oxidoreductase hao in the presence of ammonium. Unraveling the gene regulation of carbon and nitrogen metabolism helps to understand the underlying physiological adaptations of strain SolV in view of the harsh conditions of its natural ecosystem. PMID:22848206

Khadem, Ahmad F.; Pol, Arjan; Wieczorek, Adam S.; Jetten, Mike S. M.; Op den Camp, Huub J. M.

2012-01-01

218

Optical and electrical characterization of CdS-Glycine thin films with ammonia free buffer grown at different temperatures for solar cells applications  

NASA Astrophysics Data System (ADS)

In this work we report the fabrication and electro-optical characterization of CdS thin films using glycine as complexing agent with ammonia and ammonia free buffer by the Chemical Bath Deposition (CBD) method. The CdS thin films were grown at different temperatures of 50, 60, 70 and 80 °C in a thermal water bath. The morphology of these films was determined using atomic force microscopy; the resultant films were homogeneous, well adhered to the substrate, and specularly reflecting with a varying color depending on the deposition temperature. Transmittance and reflectance measurements of thermally treated CdS films were carried to study the effect of the ammonia buffer on its optical properties and bandgap. The crystallinity of the CdS thin films was determined by means of X Ray diffraction measurements. Therefore, for this study, an ammonia-free complexing agent has been taken for the deposition of CdS. Among different methods, which are being used for the preparation of CdS films, Chemical Bath Deposition (CBD) is the most attractive due to its low cost, easy to handle and large possibilities regarding doping and deposition on various substrates. In particular it can be used to easily obtain field effect devices by depositing CdS thin films over a SiO2/Si substrate. Heterostructures with interesting physical properties can be imagined, realized and tested in this way.. Structures CdS/PbS also were realized and have shown good solar cell characteristics.

Berman-Mendoza, D.; Quiñones-Urías, D.; Ferra-González, S.; Vera-Marquina, A.; Rojas-Hernández, A.; Gómez Fuentes, R.; García-Juárez, A.; Leal-Cruz, A. L.; Ramos-Carrasco, A.

2013-11-01

219

Video of Tissue Grown in Space in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

Principal investigator Leland Chung grew prostate cancer and bone stromal cells aboard the Space Shuttle Columbia during the STS-107 mission. Although the experiment samples were lost along with the ill-fated spacecraft and crew, he did obtain downlinked video of the experiment that indicates the enormous potential of growing tissues in microgravity. Cells grown aboard Columbia had grown far larger tissue aggregates at day 5 than did the cells grown in a NASA bioreactor on the ground.

2003-01-01

220

The Application of Bovine Brain Microvessel Endothelial-Cell Monolayers Grown onto Polycarbonate Membranes in Vitro to Estimate the Potential Permeability of Solutes Through the Blood–Brain Barrier  

Microsoft Academic Search

Previously our laboratory (Rim et aL, Int. J. Pharm.32:79–84, 1986) described an in vitro blood-brain barrier (BBB) model consisting of cultured bovine brain microvessel endothelial cells (BMECs) grown onto regenerated cellulose acetate membranes. However, the utility of this in vitro BBB model system was limited because the regenerated cellulose acetate membrane and not the monolayer of bovine BMECs was rate

Mandar V. Shah; Kenneth L. Audus; Ronald T. Borchardt

1989-01-01

221

Virological and serological findings in Rousettus aegyptiacus experimentally inoculated with vero cells-adapted hogan strain of Marburg virus.  

PubMed

The Egyptian fruit bat, Rousettus aegyptiacus, is currently regarded as a potential reservoir host for Marburg virus (MARV). However, the modes of transmission, the level of viral replication, tissue tropism and viral shedding pattern remains to be described. Captive-bred R. aegyptiacus, including adult males, females and pups were exposed to MARV by different inoculation routes. Blood, tissues, feces and urine from 9 bats inoculated by combination of nasal and oral routes were all negative for the virus and ELISA IgG antibody could not be demonstrated for up to 21 days post inoculation (p.i.). In 21 bats inoculated by a combination of intraperitoneal/subcutaneous route, viremia and the presence of MARV in different tissues was detected on days 2-9 p.i., and IgG antibody on days 9-21 p.i. In 3 bats inoculated subcutaneously, viremia was detected on days 5 and 8 (termination of experiment), with virus isolation from different organs. MARV could not be detected in urine, feces or oral swabs in any of the 3 experimental groups. However, it was detected in tissues which might contribute to horizontal or vertical transmission, e.g. lung, intestines, kidney, bladder, salivary glands, and female reproductive tract. Viremia lasting at least 5 days could also facilitate MARV mechanical transmission by blood sucking arthropods and infections of susceptible vertebrate hosts by direct contact with infected blood. All bats were clinically normal and no gross pathology was identified on post mortem examination. This work confirms the susceptibility of R. aegyptiacus to infection with MARV irrespective of sex and age and contributes to establishing a bat-filovirus experimental model. Further studies are required to uncover the mode of MARV transmission, and to investigate the putative role of R. aegyptiacus as a reservoir host. PMID:23029039

Paweska, Janusz T; Jansen van Vuren, Petrus; Masumu, Justin; Leman, Patricia A; Grobbelaar, Antoinette A; Birkhead, Monica; Clift, Sarah; Swanepoel, Robert; Kemp, Alan

2012-01-01

222

Virological and Serological Findings in Rousettus aegyptiacus Experimentally Inoculated with Vero Cells-Adapted Hogan Strain of Marburg Virus  

PubMed Central

The Egyptian fruit bat, Rousettus aegyptiacus, is currently regarded as a potential reservoir host for Marburg virus (MARV). However, the modes of transmission, the level of viral replication, tissue tropism and viral shedding pattern remains to be described. Captive-bred R. aegyptiacus, including adult males, females and pups were exposed to MARV by different inoculation routes. Blood, tissues, feces and urine from 9 bats inoculated by combination of nasal and oral routes were all negative for the virus and ELISA IgG antibody could not be demonstrated for up to 21 days post inoculation (p.i.). In 21 bats inoculated by a combination of intraperitoneal/subcutaneous route, viremia and the presence of MARV in different tissues was detected on days 2–9 p.i., and IgG antibody on days 9–21 p.i. In 3 bats inoculated subcutaneously, viremia was detected on days 5 and 8 (termination of experiment), with virus isolation from different organs. MARV could not be detected in urine, feces or oral swabs in any of the 3 experimental groups. However, it was detected in tissues which might contribute to horizontal or vertical transmission, e.g. lung, intestines, kidney, bladder, salivary glands, and female reproductive tract. Viremia lasting at least 5 days could also facilitate MARV mechanical transmission by blood sucking arthropods and infections of susceptible vertebrate hosts by direct contact with infected blood. All bats were clinically normal and no gross pathology was identified on post mortem examination. This work confirms the susceptibility of R. aegyptiacus to infection with MARV irrespective of sex and age and contributes to establishing a bat-filovirus experimental model. Further studies are required to uncover the mode of MARV transmission, and to investigate the putative role of R. aegyptiacus as a reservoir host. PMID:23029039

Paweska, Janusz T.; Jansen van Vuren, Petrus; Masumu, Justin; Leman, Patricia A.; Grobbelaar, Antoinette A.; Birkhead, Monica; Clift, Sarah; Swanepoel, Robert; Kemp, Alan

2012-01-01

223

Investigation of anodic and chemical oxides grown on p-type InP with applications to surface passivation for n(+)-p solar cell fabrication  

NASA Technical Reports Server (NTRS)

Most of the previously reported InP anodic oxides were grown on a n-type InP with applications to fabrication of MISFET structures and were described as a mixture of In2O3 and P2O5 stoichiometric compounds or nonstoichiometric phases which have properties similar to crystalline compounds In(OH)3, InPO4, and In(PO3)3. Details of the compositional change of the anodic oxides grown under different anodization conditions were previously reported. The use of P-rich oxides grown either by anodic or chemical oxidation are investigated for surface passivation of p-type InP and as a protective cap during junction formation by closed-ampoule sulfur diffusion. The investigation is based on but not limited to correlations between PL intensity and X-ray photoelectron spectroscopy (XPS) chemical composition data.

Faur, Maria; Faur, Mircea; Goradia, Manju; Goradia, Chandra; Jenkins, Phillip; Jayne, Douglas; Weinberg, Irving

1991-01-01

224

High titer growth of human and avian influenza viruses in an immortalized chick embryo cell line without the need for exogenous proteases.  

PubMed

The current method of growing influenza virus for vaccine production is through the use of embryonated chicken eggs. This manufacturing system yields a low concentration of virus per egg, requires significant downstream production for purification, and demands a considerable amount of time for production. We have demonstrated an immortalized chick embryo cell line, termed PBS-1, is capable of growing unmodified recent isolates of human and avian influenza A and B viruses to extremely high titers. In many cases, PBS-1 cells out perform primary chick embryo kidney (CEK) cells, Madin-Darby Canine Kidney (MDCK) cells and African green monkey kidney cells (Vero) in growth of recent influenza isolates. PBS-1 cells are free of any exogenous agents, are non-tumorigenic, and are readily adaptable to a variety of culture conditions, including growth on microcarrier beads. Influenza viruses grown in PBS-1 cells are released into the culture fluid without the need for exogenous proteases, thus simplifying downstream processing. In addition to offering a significant improvement in vaccine production, PBS-1 cells should prove valuable in diagnostics and as a cell line of choice for influenza virus research. PMID:18524432

Smith, Kristen A; Colvin, Christopher J; Weber, Patty S D; Spatz, Stephen J; Coussens, Paul M

2008-07-01

225

Investigation of H2/CH4 mixed gas plasma post-etching process for ZnO:B front contacts grown by LP-MOCVD method in silicon-based thin-film solar cells  

NASA Astrophysics Data System (ADS)

A new plasma post-etching method, H2/CH4 mixed gas plasma, is introduced to modify ZnO:B films grown by LP-MOCVD technique, successfully relaxing the double trade-offs, i.e., transparency/conductivity trade-off and surface texture/Voc and FF trade-off. To deeply evaluate the post-etching process, optical emission spectroscopy technique is applied to diagnose the plasma condition. Upon different etching power, three distinct possible etching mechanisms are identified by analyzing the evolution of H?*, H?*, CH* emission species in the plasma space. It is demonstrated that H?* and CH* species are responsible for the physical etching process and chemical etching process, respectively, from which a new “soft” surface morphology is formed with a combination of micro- and nano-sized texture. Additionally, H?* species can bond with ZnO and also passivate the grains boundaries, thereby making both the carrier concentration and hall mobility increase. This process is defined as chemical bonding process. Finally, pin-type a-Si:H single-junction solar cells with an optimized device structure is grown on the etched ZnO:B substrate. The corresponding electrical parameters, such as Jsc, Voc and FF, are simultaneously improved compared with the solar cell deposited on as-grown ZnO:B substrate with the same fabrication process. As a consequence, a noteworthy 8.85% conversion-efficiency is achieved with an absorber layer thickness only 160 nm.

Wang, Li; Zhang, Xiaodan; Zhao, Ying; Yamada, Takuto; Naito, Yusuke

2014-10-01

226

Isolation and identification of a novel chlorophenol from a cell suspension culture of Helichrysum aureonitens.  

PubMed

A novel chlorophenol, 4-chloro-2-(hepta-1,3,5-triyn-1-yl)-phenol (1), was isolated as the major phenolic compound from the cells of Helichrysum aureonitens suspension cultures. Compound 1 has been proposed to be an intermediate in the acetylene biosynthetic pathway of other acetylenic compounds in Helichrysum spp. The ethanol extract of cell suspension cultures and compound 1 were evaluated for their cytotoxicity against monkey kidney Vero (Vero cells) and human prostate epithelial carcinoma (DU145) cell lines, also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Mycobacterium tuberculosis H37Rv were determined as well. PMID:19881282

Ziaratnia, Seyed Mahdi; Ohyama, Kiyoshi; Hussein, Ahmed Abdel-Fattah; Muranaka, Toshiya; Lall, Namrita; Kunert, Karl Josef; Meyer, Jacobus Johannes Marion

2009-11-01

227

Adaptation of Puumala Hantavirus to Cell Culture Is Associated with Point Mutations in the Coding Region of the L Segment and in the Noncoding Regions of the S Segment  

Microsoft Academic Search

We previously developed a model for studies on hantavirus host adaptation and initiated genetic analysis of Puumala virus variants passaged in colonized bank voles and in cultured Vero E6 cells. With the data presented in this paper, the sequence comparison of the wild-type and Vero E6-adapted variants of Puumala virus, strain Kazan, has been completed. The only amino acid substitution

Kirill Nemirov; A. Lundkvist; A. Vaheri; A. Plyusnin

2003-01-01

228

Bovine ephemeral fever virus in cell culture and mice  

Microsoft Academic Search

Summary Light, immunofluorescent and electron microscopic observations were carried out sequentially on mice and VERO cell cultures infected with bovine ephemeral fever (BEF) virus. In early harvests from cell culture, 185×73 nm cone-shaped particles with nearly parallel sides predominated; these particles had all other features typical of the Rhabdoviruses (surface projections, envelope, axial channel, precisely coiled helical nucleocapsid with 35

Frederick A. Murphy; William P. Taylor; Cedric A. Mims; Sylvia G. Whitfield

1972-01-01

229

Antiviral activity of Aloe vera against herpes simplex virus type 2: An in vitro study  

Microsoft Academic Search

In this study we tested the antiviral activity of a crude hot glycerine extract of Aloe vera gel which was grown in Bushehr (Southwest of Iran) against HSV-2 replication in Vero cell line. The extract showed antiviral activity against HSV-2 not only before attachment and entry of virus to the Vero cells but also on post attachment stages of virus

Moloud Abbas; Persian Gulf

230

Characterization and Comparison of Strained Si1-yCy Metal Oxide Semiconductor Field-Effect Transistor Grown by Gas-Source Molecular Beam Epitaxy and Hot Wire Cell Method  

NASA Astrophysics Data System (ADS)

Strained Si1-yCy metal oxide semiconductor field-effect transistors (MOSFETs) were fabricated by gas-source molecular beam epitaxy (GS-MBE) and the Hot Wire (HW) Cell method, and their electrical characteristics were compared. The strained Si1-yCy films were grown by GS-MBE at 600°C and by the HW-Cell method at 200°C. The electron mobility of the MOSFET fabricated by GS-MBE showed a large decrease while that fabricated by the HW-Cell method showed a slight decrease. It was considered that this difference was due to the difference in non-substitutional carbon content. We found that the increase in growth temperature caused the decrease in substitutional carbon content and increase in non-substitutional carbon content. These results indicated that lowering the growth temperature decreases the non-substitutional carbon content and improves the electrical characteristics of Si1-yCy films.

Watahiki, Tatsuro; Ishihara, Hanae; Abe, Katsuya; Yamada, Akira; Konagai, Makoto

2004-04-01

231

Physical and Microstructural Properties of Radio-Frequency Plasma-Enhanced Chemical Vapor Deposition Grown n-Type Phosphorus Doped Amorphous Carbon Films on the Contribution to Carbon-Based Solar Cells  

NASA Astrophysics Data System (ADS)

The physical and microstructural properties of phosphorus doped n-type amorphous carbon (n-C:P) films grown from a radio-frequency (rf) discharge in methane gas as a function of rf power (Prf) was previously determined, and their influence on the electronic properties is now analyzed. It is shown that Prf plays a major role in the deposition of n-C:P films. The Raman scattering, Fourier transform infrared spectroscopy (FTIR), optical spectroscopy, Electron spin resonance (ESR) analyses and electrical resistivity measurement have confirmed successfull phosphorus doping. Moreover, the fabricated n-C:P on p-type silicon substrates (n-C:P/p-Si) heterojunction solar cells, when exposed to AM 1.5 illumination (100 mW/cm2, 25°C) is also studied. The maximum open-circuit voltage (Voc) and short-circuit current density (Jsc) for the cells are observed to be approximately 236 V and 7.34 mA/cm2, respectively for the n-C:P/p-Si cell grown at low Prf of 100 W. The highest energy-conversion efficiency (?) and fill factor (FF) were found to be approximately 0.84 and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.

Rusop, Mohamad; Ebisu, Hiroshi; Adachi, Mitsuhiro; Soga, Tetsuo; Jimbo, Takashi

2005-08-01

232

Biology of fowl adenovirus type 1 infection of heterologous cells.  

PubMed

The JM1/1 strain of fowl adenovirus (FAV) serotype 1 isolated from gizzard erosion was used to investigate the biology of FAV in homologous (susceptible) and heterologous cells. The FAV JM1/1 strain is capable of efficient multiplication in primary chicken kidney (CK) cells, but not in Crandell-Rees feline kidney (CRFK) cells or Vero cells. FAV adsorption in heterologous cells was slightly higher than in CK cells. An early gene encoding a DNA-binding protein and a late gene encoding the hexon protein were expressed in CK cells. Only the early gene was expressed in Vero cells. Neither of these genes was expressed in CRFK cells. These results suggest that the virus was unable to multiply effectively due to suppression of viral gene expression in the heterologous cells used in this study. PMID:22814699

Taharaguchi, Satoshi; Fukazawa, Rina; Kitazume, Miho; Harima, Hayato; Taira, Kensuke; Oonaka, Kenji; Hara, Motonobu

2012-11-01

233

Gifted Children Grown Up.  

ERIC Educational Resources Information Center

This book describes the outcomes of a longitudinal study of 210 British children that compared the recognized and the unrecognized gifted with their classmates. It describes what has happened to them and their families as they have grown up in very different circumstances, in poverty or wealth, through many types of schooling and life…

Freeman, Joan

234

Impact of growth temperature and substrate orientation on dilute-nitride-antimonide materials grown by MOVPE for multi-junction solar cell application  

NASA Astrophysics Data System (ADS)

Nitrogen incorporation in bulk films of GaAsN, InGaAsN, and GaAsSbN films grown by metalorganic vapor phase epitaxy (MOVPE) on (100) and (311)B GaAs substrates was investigated. These films, nominally lattice-matched to a GaAs substrate, were deposited at relatively higher growth temperature (600 °C) than typically used for MOVPE-grown dilute-nitride materials (~500-530 °C), in order to reduce the background carbon impurity concentration. Even at these higher growth temperatures, sufficient N incorporation is achieved for targeting Eg~1 eV InGaAsN and GaAsN with low background carrier concentration (1-2×1017 cm-3). The presence of Sb is found to significantly inhibit N incorporation, making it challenging to achieve films of GaAsSbN grown at 600 °C with a sufficient N concentration to achieve a 1 eV band gap energy. For GaAsN and InGaAsN on (311)B GaAs substrates, increased N incorporation with lower background carbon concentration is observed, relative to films on (100) GaAs. By contrast, GaAsSbN on (311)B GaAs substrate exhibit lower-N incorporation relative to films on (100) GaAs, presumably due to surface site competition between Sb and N. The background hole carrier concentrations of thermally annealed InGaAsN and GaAsSbN on (311)B are about a factor of two lower than those on (100) GaAs substrate.

Kim, T. W.; Kuech, T. F.; Mawst, L. J.

2014-11-01

235

Plaque Assay of Rickettsiae in a Mammalian Cell Line  

PubMed Central

Clear-cut and repeatable plaque assays were obtained for three rickettsiae of the spotted fever group (Rickettsia rickettsi, R. conori, and R. montana) in Vero cells used in a manner similar to that for arboviruses. In addition, three typhus group agents (R. typhi, R. canada, R. prowazeki) induced plaques in these cells. In preliminary tests Coxiella burneti (Nine Mile strain) failed to produce plaques. Comparable results were obtained in plastic flasks and plastic culture trays incubated in ambient air with or without addition of N-2-hydroxyethyl-piperazine-N?-2-ethanesulfinic acid buffer. Larger and more well defined R. rickettsi plaques were produced when cultures were overlaid with Leibovitz (L15) medium than with either medium 199 or Eagle medium. Phosphate-buffered saline containing bovine plasma albumin (fraction V), in contrast to brain heart infusion broth, as a diluent for preparing inocula consistently permitted development of larger and more numerous plaques with three agents: R. rickettsi, R. conori, and R. montana. When R. rickettsi and R. typhi were assayed in parallel in primary chicken embryo cultures and Vero cells, comparable results were obtained, but with R. canada results in Vero cells were superior. In contrast, R. prowazeki produced inconsistent results in Vero cells. Images PMID:4208640

Cory, J.; Yunker, C. E.; Ormsbee, R. A.; Peacock, M.; Meibos, H.; Tallent, G.

1974-01-01

236

Bi2S3microspheres grown on graphene sheets as low-cost counter-electrode materials for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

In this work, we synthesized 3D Bi2S3 microspheres comprised of nanorods grown along the (211) facet on graphene sheets by a solvothermal route, and investigated its catalytic activities through I-V curves and conversion efficiency tests as the CE in DSSCs. Although the (211) facet has a large band gap for a Bi2S3 semiconductor, owing to the introduction of graphene into the system, its short-circuit current density, open-circuit voltage, fill factor, and efficiency were Jsc = 12.2 mA cm-2, Voc = 0.75 V, FF = 0.60, and ? = 5.5%, respectively. By integrating it with graphene sheets, our material achieved the conversion efficiency of 5.5%, which is almost triple the best conversion efficiency value of the DSSCs with (211)-faceted 3D Bi2S3 without graphene (1.9%) reported in the latest literature. Since this conversion-efficient 3D material grown on the graphene sheets significantly improves its catalytic properties, it paves the way for designing and applying low-cost Pt-free CE materials in DSSC from inorganic nanostructures.In this work, we synthesized 3D Bi2S3 microspheres comprised of nanorods grown along the (211) facet on graphene sheets by a solvothermal route, and investigated its catalytic activities through I-V curves and conversion efficiency tests as the CE in DSSCs. Although the (211) facet has a large band gap for a Bi2S3 semiconductor, owing to the introduction of graphene into the system, its short-circuit current density, open-circuit voltage, fill factor, and efficiency were Jsc = 12.2 mA cm-2, Voc = 0.75 V, FF = 0.60, and ? = 5.5%, respectively. By integrating it with graphene sheets, our material achieved the conversion efficiency of 5.5%, which is almost triple the best conversion efficiency value of the DSSCs with (211)-faceted 3D Bi2S3 without graphene (1.9%) reported in the latest literature. Since this conversion-efficient 3D material grown on the graphene sheets significantly improves its catalytic properties, it paves the way for designing and applying low-cost Pt-free CE materials in DSSC from inorganic nanostructures. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr06093d

Li, Guang; Chen, Xiaoshuang; Gao, Guandao

2014-02-01

237

Free amino acid and phenolic contents and antioxidative and cancer cell-inhibiting activities of extracts of 11 greenhouse-grown tomato varieties and 13 tomato-based foods.  

PubMed

Tomato (Solanum lycopersicum) plants synthesize nutrients, pigments, and bioactive compounds that benefit nutrition and human health. The nature and concentrations of these compounds are strongly influenced by varietal factors such as size and color as well as by processing. To better understand how these factors affect the concentration of nutrients and bioactive compounds, we analyzed 11 Korean tomato varieties grown under the same greenhouse conditions and 13 processed commercial tomato products for free amino acids and amino acid metabolites by HPLC, for individual phenolics by HPLC-MS, for total phenolics by the Folin-Ciocalteu method, for antioxidative activity by the FRAP and DPPH methods, and for cancer cell-inhibiting effects by the MTT assay. We also determined the protein content of the tomatoes by an automated Kjeldahl method. The results show that there is a broad range of bioactive compounds across tomato varieties and products. Small tomatoes had higher contents of bioactive compounds than the large ones. The content of phenolic compounds of processed products was lower than that of fresh tomatoes. Tomato extracts promoted growth in normal liver (Chang) cells, had little effect in normal lung (Hel299) cells, mildly inhibited growth of lung cancer (A549) cells, and first promoted and then, at higher concentrations, inhibited growth in lymphoma (U937) cells. The relationship of cell growth to measured constituents was not apparent. Dietary and health aspects of the results are discussed. PMID:22070764

Choi, Suk-Hyun; Kim, Hyen-Ryung; Kim, Hyun-Jeong; Lee, In-Seon; Kozukue, Nobuyuki; Levin, Carol E; Friedman, Mendel

2011-12-28

238

[Ebola virus reproduction in cell cultures].  

PubMed

Ebola-Zaire virus production in Vero and BGM cells was studied. The CPE developed in both cell cultures. The cell monolayer destruction by 80-90% was seen at a low multiplicity of infection in 7-8 days after virus inoculation. An overlay composition was developed for virus titration using plaque assay. The plaque production was shown to be directly proportional to the virus dose. The curve of Ebola virus production in Vero cell culture fluid was determined. At a multiplicity of infection of 0.01 PFU/cell, the maximum virus titer of 10(6.4) PFU/ml was reached in 7 days postinfection. Specific antisera were generated by inoculation of guinea pigs. Indirect immunofluorescent assay was used for testing of virus-specific antigen and antibody. PMID:1279896

Titenko, A M; Novozhilov, S S; Andaev, E I; Borisova, T I; Kulikova, E V

1992-01-01

239

Phyllosphere of Organically Grown Strawberries  

E-print Network

Phyllosphere of Organically Grown Strawberries Interactions between the Resident Microbiota, Alnarp Print: SLU Service/Repro, Alnarp 2013 #12;Phyllosphere of Organically Grown Strawberries of biological control agents (BCAs) is regarded as a promising measure to control important foliar strawberry

240

Studies on the Production of Digitalis Cardenolides by Plant Tissue Culture: II. EFFECT OF LIGHT AND PLANT GROWTH SUBSTANCES ON DIGITOXIN FORMATION BY UNDIFFERENTIATED CELLS AND SHOOT-FORMING CULTURES OF DIGITALIS PURPUREA L. GROWN IN LIQUID MEDIA.  

PubMed

Undifferentiated, highly chlorophyllous cell cultures; undifferentiated white cell cultures; green, shoot-forming cultures; and white, shoot-forming cultures of Digitalis purpurea L. were established and subcultured every 3 weeks in liquid media in the light or in the dark. The digitoxin content, the chlorophyll content, and the ribulose bisphosphate carboxylase activity of these cultures were assayed. The light-grown, green, shoot-forming cultures accumulated considerable amounts of digitoxin (about 20 to 40 micrograms per gram dry weight), and the white, shoot-forming cultures without chloroplasts accumulated about one-third that amount of digitoxin. The chlorophyll content and the ribulose bisphosphate carboxylase activity of the undifferentiated green cells were about the same as they were in the green, shoot-forming cultures, but the digitoxin content of the former was extremely low (about 0.05 to 0.2 microgram per gram dry weight), which is about the same as that in undifferentiated white cells without chloroplasts. Thus, it was concluded that the chloroplasts are not essential for the synthesis of digitoxin in Digitalis cells. The optimum concentrations of the tested compounds for accumulation of digitoxin were: benzyladenine, 0.01 to 1 milligram per liter; indoleacetic acid, 0.1 to 1 milligram per liter; alpha-naphthaleneacetic acid; 0.1 milligram per liter; and 2,4-dichlorophenoxyacetic acid, 0.01 milligram per liter. PMID:16662267

Hagimori, M; Matsumoto, T; Obi, Y

1982-03-01

241

Graphic Grown Up  

ERIC Educational Resources Information Center

It's no secret that children and YAs are clued in to graphic novels (GNs) and that comics-loving adults are positively giddy that this format is getting the recognition it deserves. Still, there is a whole swath of library card-carrying grown-up readers out there with no idea where to start. Splashy movies such as "300" and "Spider-Man" and their…

Kim, Ann

2009-01-01

242

Acute exposure to a 2?mT static magnetic field affects ionic homeostasis of in vitro grown porcine granulosa cells.  

PubMed

In this work, we provided direct evidence for the first time that exposure to a static magnetic field (SMF) of low intensity (2?mT) is immediately followed by a reversible cell membrane depolarization wave (of about 1?min) that causes the rise of intracellular calcium and the decrease of mitochondrial activity of vital granulosa cells. These effects are likely due to the increase in Na(+) and Ca(2+) cell membrane permeability. PMID:24436211

Bernabò, Nicola; Saponaro, Ilaria; Tettamanti, Enzo; Mattioli, Mauro; Barboni, Barbara

2014-04-01

243

Lipid peroxidation and activities of tyrosine aminotransferase and glutamine synthetase in hepatoma and glioma cells grown in bovine colostrum-supplemented medium  

Microsoft Academic Search

Summary  The growth stimulating properties of bovine serum and colostrum were compared in rat hepatoma (HTC) and glioma (C6) cell cultures.\\u000a A colostrum concentration of 2% was optimal for HTc cells, which then reached a terminal density 40% of that in serum-supplemented\\u000a medium. The corresponding figures for C6 cells were 10 and 81%, respectively. After 4 d in culture, levels of

Lena Odland; Stefan Wallin; Erik Walum

1986-01-01

244

Differences in Chlamydia trachomatis Serovar E Growth Rate in Polarized Endometrial and Endocervical Epithelial Cells Grown in Three-Dimensional Culture?  

PubMed Central

In vitro studies of obligate intracellular chlamydia biology and pathogenesis are highly dependent on the use of experimental models and growth conditions that mimic the mucosal architecture and environment these pathogens encounter during natural infections. In this study, the growth of Chlamydia trachomatis genital serovar E was monitored in mouse fibroblast McCoy cells and compared to more relevant host human epithelial endometrium-derived HEC-1B and cervix-derived HeLa cells, seeded and polarized on collagen-coated microcarrier beads, using a three-dimensional culture system. Microscopy analysis of these cell lines prior to infection revealed morphological differences reminiscent of their in vivo architecture. Upon infection, early chlamydial inclusion distribution was uniform in McCoy cells but patchy in both epithelial cell lines. Although no difference in chlamydial attachment to or entry into the two genital epithelial cell lines was noted, active bacterial genome replication and transcription, as well as initial transformation of elementary bodies to reticulate bodies, were detected earlier in HEC-1B than in HeLa cells, suggesting a faster growth, which led to higher progeny counts and titers in HEC-1B cells upon completion of the developmental cycle. Chlamydial development in the less relevant McCoy cells was very similar to that in HeLa cells, although higher progeny counts were obtained. In conclusion, this three-dimensional bead culture system represents an improved model for harvesting large quantities of infectious chlamydia progeny from their more natural polarized epithelial host cells. PMID:17088348

Guseva, Natalia V.; Dessus-Babus, Sophie; Moore, Cheryl G.; Whittimore, Judy D.; Wyrick, Priscilla B.

2007-01-01

245

A new isoflavone glycitein 7-O-beta-D-glucoside 4''-O-methylate, isolated from Cordyceps militaris grown on germinated soybeans extract, inhibits EGF-induced mucus hypersecretion in the human lung mucoepidermoid cells.  

PubMed

A new isoflavone glycitein 7-O-beta-d-glucoside 4''-O-methylate (CGLM) has been isolated recently from Cordyceps militaris grown on germinated soybean extract and has antioxidant activity. In the present study, CGLM was investigated for its suppression of airway mucous hyper-secretion in epidermal growth factor (EGF)-treated human lung mucoepidermoid cells. NCI-H292 cells were treated with CGLM for 1?h, followed by EGF treatment for 24?h. The decrease in cyclooxygenase-2 (COX-2) production was correlated with reduced levels of protein and mRNA of inducible matrix metalloproteinase 9 (MMP-9) and also MUC5AC gene expression. CGLM directly inhibited down-regulated NF-?B activity, and significantly inhibited the phosphorylation of p38 and ERK1/2 (p42/p44) in NCI-H292 cells. These results suggest that CGLM protects NCI-H292 cells from EGF-induced damage by down-regulation of COX-2, MMP-9 and MUC5AC gene expression, mediated via blocking the NF-kappa-B and p38/ERK MAPK pathways. PMID:22407817

Kim, Jung-Hee; Park, Dong Ki; Lee, Choong Hwan; Yoon, Do-Young

2012-12-01

246

Patterns of microRNA Expression in Non-Human Primate Cells Correlate with Neoplastic Development In Vitro  

PubMed Central

MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression post-transcriptionally. They play a critical role in developmental and physiological processes and have been implicated in the pathogenesis of several diseases including cancer. To identify miRNA signatures associated with different stages of neoplastic development, we examined the expression profile of 776 primate miRNAs in VERO cells (a neoplastically transformed cell line being used for the manufacture of viral vaccines), progenitor primary African green monkey kidney (pAGMK) cells, and VERO cell derivatives: spontaneously immortalized, non-tumorigenic, low-passage VERO cells (10-87 LP); tumorigenic, high-passage VERO cells (10-87 HP); and a cell line (10-87 T) derived from a 10-87 HP cell tumor xenograft in athymic nude mice. When compared with pAGMK cells, the majority of miRNAs were expressed at lower levels in 10-87 LP, 10-87 HP, and 10-87 T cells. We identified 10 up-regulated miRNAs whose level of expression correlated with VERO cell evolution from a non-tumorigenic phenotype to a tumorigenic phenotype. The overexpression of miR-376a and the polycistronic cluster of miR-376a, miR-376b and miR-376c conferred phenotypic changes to the non-tumorigenic 10-87 LP cells that mimic the tumorigenic 10-87 HP cells. Thirty percent of miRNAs that were components of the identified miRNAs in our spontaneously transformed AGMK cell model are also dysregulated in a variety of human tumors. These results may prove to be relevant to the biology of neoplastic development. In addition, one or more of these miRNAs could be biomarkers for the expression of a tumorigenic phenotype. PMID:21203544

Teferedegne, Belete; Murata, Haruhiko; Quinones, Mariam; Peden, Keith; Lewis, Andrew M.

2010-01-01

247

Novel cell-based method to detect Shiga toxin 2 from Escherichia coli O157:H7 and inhibitors of toxin activity.  

PubMed

Escherichia coli O157:H7 is a leading cause of food-borne illness. This human pathogen produces Shiga toxins (Stx1 and Stx2) which inhibit protein synthesis by inactivating ribosome function. The present study describes a novel cell-based assay to detect Stx2 and inhibitors of toxin activity. A Vero cell line harboring a destabilized variant (half-life, 2 h) of the enhanced green fluorescent protein (d2EGFP) was used to monitor the toxin-induced inhibition of protein synthesis. This Vero-d2EGFP cell line produced a fluorescent signal which could be detected by microscopy or with a plate reader. However, a greatly attenuated fluorescent signal was detected in Vero-d2EGFP cells that had been incubated overnight with either purified Stx2 or a cell-free culture supernatant from Stx1- and Stx2-producing E. coli O157:H7. Dose-response curves demonstrated that the Stx2-induced inhibition of enhanced green fluorescent protein fluorescence mirrored the Stx2-induced inhibition of overall protein synthesis and identified a picogram-per-milliliter threshold for toxin detection. To establish our Vero-d2EGFP assay as a useful tool for the identification of toxin inhibitors, we screened a panel of plant compounds for antitoxin activities. Fluorescent signals were maintained when Vero-d2EGFP cells were exposed to Stx1- and Stx2-containing medium in the presence of either grape seed or grape pomace extract. The antitoxin properties of the grape extracts were confirmed with an independent toxicity assay that monitored the overall level of protein synthesis in cells treated with purified Stx2. These results indicate that the Vero-d2EGFP fluorescence assay is an accurate and sensitive method to detect Stx2 activity and can be utilized to identify toxin inhibitors. PMID:19139230

Quiñones, Beatriz; Massey, Shane; Friedman, Mendel; Swimley, Michelle S; Teter, Ken

2009-03-01

248

Antigenic properties and diagnostic potential of puumala virus nucleocapsid protein expressed in insect cells.  

PubMed Central

Puumala virus (PUU) is a member of the genus Hantavirus in the family Bunyaviridae and the causative agent of nephropathia epidemica, a European form of hemorrhagic fever with renal syndrome. Sera of nephropathia epidemica patients react specifically with PUU nucleocapsid (N) protein. In order to safely provide large quantities of antigen for diagnostic purposes, PUU Sotkamo strain N protein was expressed by using the baculovirus system in Sf9 insect cells to up to 30 to 50% of the total cellular protein. The recombinant N protein (bac-PUU-N) was solubilized with 6 M urea, dialyzed, and purified by anion-exchange liquid chromatography. In an immunoglobulin M mu-capture assay purified and unpurified bac-PUU-N antigen showed identical results compared with the results of a similar assay based on native PUU antigen grown in Vero E6 cells. An immunoglobulin G monoclonal antibody-capture assay based on unpurified bac-PUU-N also showed results identical to those of an assay with native PUU-N antigen. Moreover, a panel of monoclonal antibodies reactive with eight different epitopes showed identical reactivity patterns with both natural and bac-PUU-N antigen, while two epitopes in PUU-N expressed as a fusion protein in Escherichia coli were not recognized. Puumala hantavirus N protein expressed by the baculovirus system offers a safe and inexpensive source of specific antigen for large-scale diagnostic and seroepidemiological purposes. PMID:8748286

Vapalahti, O; Lundkvist, A; Kallio-Kokko, H; Paukku, K; Julkunen, I; Lankinen, H; Vaheri, A

1996-01-01

249

Antibacterial effect of theaflavin, polyphenon 60 ( Camellia sinensis) and Euphorbia hirta on Shigella spp. — a cell culture study  

Microsoft Academic Search

Antibacterial effect of compounds extracted from Camellia sinensis L. and the methanol extract of Euphorbia hirta L. were studied against dysentery causing Shigella spp. using the Vero cell line. Cytotoxicity studies of the extracts were performed using the cell line and the non-cytotoxic concentration of the extract was tested for antibacterial activity against the cytopathic dose of the pathogen. These

K. Vijaya; S. Ananthan; R. Nalini

1995-01-01

250

Survival and cell culturability of biocontrol Pseudomonas fluorescens CHA0 in the rhizosphere of cucumber grown in two soils of contrasting fertility status  

Microsoft Academic Search

The effect of cucumber roots on survival patterns of the biocontrol soil inoculant Pseudomonas fluorescens CHA0-Rif was assessed for 22?days in two non-sterile soils, using a combination of total immunofluorescence cell counts,\\u000a Kogure's direct viable counts and colony counts on plates containing rifampicin. In Eschikon soil (high fertility status for\\u000a cucumber), CHA0-Rif persisted as culturable cells in bulk soil and

C. Hase; M. Hottinger; Y. Moënne-Loccoz; G. Défago

2000-01-01

251

N/P InP homojunction solar cells with an In0.53Ga0.47As contacting layer grown by liquid phase epitaxy  

NASA Technical Reports Server (NTRS)

N/P InP homojunction solar cells with an In sub 0.53 Ga sub 0.47 As contacting layer were fabricated by liquid phase epitaxy (LPE). Electron-Beam-Induced-Current (EBIC) measurements were performed on several selected samples. It was found that the background doping level in the base region sometimes results in a deep junction, which greatly affects the cell performance.

Shen, C. C.; Choi, K. Y.

1989-01-01

252

High-efficiency screen-printed solar cell on edge-defined film-fed grown ribbon silicon through optimized rapid belt co-firing of contacts and high-sheet-resistance emitter  

NASA Astrophysics Data System (ADS)

High-quality screen-printed contacts were achieved on a high-sheet-resistance emitter (˜100 ?/sq.) using PV168 Ag paste and rapid co-firing in the belt furnace. The optimized co-firing cycle developed for a 100 ?/sq. emitter produced 16.1% efficient 4 cm2 planar edge-defined film-fed grown (EFG) ribbon Si cells with a low series-resistance (0.8 ? cm2), high fill factor of ˜0.77, along with very significant bulk lifetime enhancement from 3 to 100 ?s. This represents the highest-efficiency screen-printed EFG Si cells with single-layer antireflection (AR) coating. These cells were fabricated using a simple process involving POCl3 diffusion for a high-sheet-resistance emitter, SiNx AR coating and rapid cofiring of Ag grid and Al-doped back-surface field in a conventional belt furnace. The rapid cofiring process also prevented junction shunting while maintaining very effective SiNx-induced hydrogen passivation of defects, resulting in an average bulk lifetime exceeding 100 ?s.

Rohatgi, Ajeet; Hilali, Mohamed M.; Nakayashiki, Kenta

2004-04-01

253

25.5% efficient Ga{sub 0.35}In{sub 0.65}P/Ga{sub 0.83}In{sub 0.17}As tandem solar cells grown on GaAs substrates  

SciTech Connect

Theoretical calculations predict a higher power conversion efficiency for the combination of Ga{sub 0.35}In{sub 0.65}P and Ga{sub 0.83}In{sub 0.17}As in a tandem solar cell, compared to the more commonly used Ga{sub 0.51}In{sub 0.49}P/GaAs approach. A record conversion efficiency of 21.6% (AM1.5g) was recently achieved for a 1.18 eV Ga{sub 0.83}In{sub 0.17}As solar cell, grown lattice-mismatched to the GaAs substrate material. This paper reports on the device characteristics of first Ga{sub 0.35}In{sub 0.65}P/Ga{sub 0.83}In{sub 0.17}As tandem solar cells based on this very promising GaInAs material. A high quantum efficiency, comparable to the lattice-matched Ga{sub 0.51}In{sub 0.49}P on GaAs approach was achieved. A power conversion efficiency of 25.5% was measured under AM1.5d spectral conditions.

Dimroth, F.; Schubert, U.; Bett, A.W.

2000-05-01

254

Reorganization of structural proteins in vascular smooth muscle cells grown in collagen gel and basement membrane matrices (Matrigel): a comparison with their in situ counterparts.  

PubMed

When smooth muscle cells are enzyme-dispersed from tissues they lose their original filament architecture and extracellular matrix surrounds. They then reorganize their structural proteins to accommodate a 2-D growth environment when seeded onto culture dishes. The aim of the present study was to determine the expression and reorganization of the structural proteins in rabbit aortic smooth muscle cells seeded into 3-D collagen gel and Matrigel (a basement membrane matrix). It was shown that smooth muscle cells seeded in both gels gradually reorganize their structural proteins into an architecture similar to that of their in vivo counterparts. At the same time, a gradual decrease in levels of smooth muscle-specific contractile proteins (mainly smooth muscle myosin heavy chain-2) and an increase in beta-nonmuscle actin occur, independent of both cell growth and extracellular matrix components. Thus, smooth muscle cells in 3-D extracellular matrix culture and in vivo have a similar filament architecture in which the contractile proteins such as actin, myosin, and alpha-actinin are organized into longitudinally arranged "myofibrils" and the vimentin-containing intermediate filaments form a meshed cytoskeletal network. However, the myofibrils reorganized in vitro contain less smooth muscle-specific and more nonmuscle contractile proteins. PMID:11356063

Song, J; Rolfe, B E; Hayward, I P; Campbell, G R; Campbell, J H

2001-01-01

255

Authentication of the R06E Fruit Bat Cell Line  

PubMed Central

Fruit bats and insectivorous bats are believed to provide a natural reservoir for a wide variety of infectious diseases. Several lines of evidence, including the successful isolation of infectious viruses, indicate that Marburg virus and Ravn virus have found a major reservoir in colonies of the Egyptian rousette (Rousettus aegyptiacus). To facilitate molecular studies on virus-reservoir host interactions and isolation of viruses from environmental samples, we established cell lines from primary cells of this animal. The cell lines were given to several laboratories until we realized that a contamination with Vero cells in one of the cultures had occurred. Here we describe a general diagnostic procedure for identification of cross-species contamination with the focus on Vero and Rousettus cell lines, and summarize newly discovered properties of the cell lines that may pertain to pathogen discovery. PMID:22754654

Jordan, Ingo; Munster, Vincent J.; Sandig, Volker

2012-01-01

256

In vitro cytotoxic activity of seed oil of fenugreek against various cancer cell lines.  

PubMed

In the present study, investigations were carried out to screen the anticancer activities of fenugreek seed oil against cancer cell lines (HEp-2, MCF-7, WISH cells), and a normal cell line (Vero cells). Cytotoxicity was assessed with MTT and NRU assays, and cellular morphological alterations were studied using phase contrast light microscopy. All cells were exposed toi 10-1000 ?g/ml of fenugreek seed oil for 24 h. The results show that fenugreek seed oil significantly reduced the cell viability, and altered the cellular morphology in a dose dependent manner. Among the cell lines, HEp-2 cells showed the highest decrease in cell viability, followed by MCF-7, WISH, and Vero cells by MTT and NRU assays. Cell viability at 1000 ?g/ml was recorded as 55% in HEp-2 cells, 67% in MCF-7 cells, 75% in WISH cells, and 86% in Vero cells. The present study provides preliminary screening data for fenugreek seed oil pointing to potent cytotoxicity against cancer cells. PMID:23679282

Al-Oqail, Mai Mohammad; Farshori, Nida Nayyar; Al-Sheddi, Ebtesam Saad; Musarrat, Javed; Al-Khedhairy, Abdulaziz Ali; Siddiqui, Maqsood Ahmed

2013-01-01

257

Prostate tumor grown in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

This prostate cancer construct was grown during NASA-sponsored bioreactor studies on Earth. Cells are attached to a biodegradable plastic lattice that gives them a head start in growth. Prostate tumor cells are to be grown in a NASA-sponsored Bioreactor experiment aboard the STS-107 Research-1 mission in 2002. Dr. Leland Chung of the University of Virginia is the principal investigator. 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. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage 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). 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. Credit: NASA and the University of Virginia.

2001-01-01

258

Proliferation, Hormonal Responsiveness, and Estrogen Receptor Content of MCF7 Human Breast Cancer Cells Grown in the Short-Terni and Long-Term Absence of Estrogens1  

Microsoft Academic Search

We have examined the effect of short-term and long-term growth in the absence of estrogens on the proliferation rate and estrogen and antiestrogen responsiveness of MCF-7 human breast cancer cells. The removal of phenol red, the pH indicator in tissue culture medium that is weakly estrogenic (Y. Berthois et al., Proc. Nati. Acad. Sci. USA, 83: 2496-2500, 1986), immediately slows

Benita S. Katzenellenbogen; Kari L. Rendra; Mary Jane Norman; Yolande Berthois

259

Transparent Conducting ZnO:B Thin Films Grown by Ultraviolet Light Assisted Metal Organic Chemical Vapor Deposition Using Triethylboron for Cu(In,Ga)Se2 Solar Cells  

NASA Astrophysics Data System (ADS)

High-efficiency cadmium-free Cu(In,Ga)Se2 (CIGS) thin-film solar cells have been fabricated using a zinc compound buffer layer deposited by the chemical bath deposition (CBD) process. However, the zinc compound buffer layers such as ZnS(O,OH) are prone to plasma-induced damage during the subsequent ZnO sputtering process. A process causing less damage such as metal-organic chemical vapor deposition (MOCVD) is thus required for ZnO-based transparent conducting oxide (TCO) layers. In the present work, the boron-doped zinc oxide (ZnO:B) films were grown by MOCVD using diethyl zinc (DEZ), H2O, and low-toxicity triethylboron (TEB). An UV-assisted MOCVD process was developed in order to reduce the resistivity of ZnO:B films. As a result, the resisitivity significantly decreased together with the increased electron mobility and carrier concentration. The comparison of performance was also carried out for the ZnS(O,OH)/CIGS solar cells with MOCVD-deposited ZnO:B and sputter-deposited ZnO:Al window layers.

Kobayashi, Taizo; Yamauchi, Kotaro; Mise, Takahiro; Nakada, Tokio

2012-10-01

260

Production and characterization of high-titer serum-free cell culture grown hepatitis C virus particles of genotype 1-6.  

PubMed

Recently, cell culture systems producing hepatitis C virus particles (HCVcc) were developed. Establishment of serum-free culture conditions is expected to facilitate development of a whole-virus inactivated HCV vaccine. We describe generation of genotype 1-6 serum-free HCVcc (sf-HCVcc) from Huh7.5 hepatoma cells cultured in adenovirus expression medium. Compared to HCVcc, sf-HCVcc showed 0.6-2.1 log10 higher infectivity titers (4.7-6.2 log10 Focus Forming Units/mL), possibly due to increased release and specific infectivity of sf-HCVcc. In contrast to HCVcc, sf-HCVcc had a homogeneous single-peak density profile. Entry of sf-HCVcc depended on HCV co-receptors CD81, LDLr, and SR-BI, and clathrin-mediated endocytosis. HCVcc and sf-HCVcc were neutralized similarly by chronic-phase patient sera and by human monoclonal antibodies targeting conformational epitopes. Thus, we developed serum-free culture systems producing high-titer single-density sf-HCVcc, showing similar biological properties as HCVcc. This methodology has the potential to advance HCV vaccine development and to facilitate biophysical studies of HCV. PMID:24928051

Mathiesen, Christian K; Jensen, Tanja B; Prentoe, Jannick; Krarup, Henrik; Nicosia, Alfredo; Law, Mansun; Bukh, Jens; Gottwein, Judith M

2014-06-01

261

Detection of the quantity of kinesin and microgravity-sensitive kinesin genes in rat bone marrow stromal cells grown in a simulated microgravity environment  

NASA Astrophysics Data System (ADS)

Kinesin and kinesin-like proteins (KLPs) constitute a superfamily of microtubule motor proteins found in all eukaryotic organisms. Members of the kinesin superfamily are known to play important roles in many fundamental cellular and developmental processes. To date, few published studies have reported on the effects of microgravity on kinesin expression. In this paper, we describe the expression pattern and microgravity-sensitive genes of kinesin in rat bone marrow stromal cells cultured in a ground-based rotating bioreactor. The quantity of kinesin under the clinorotation condition was examined by immunoblot analysis with anti-kinesin. Furthermore, the distribution of kinesin at various times during clinorotation was determined by dual immunostaining, using anti-kinesin monoclonal antibody or anti-?-tubulin monoclonal antibody. In terms of kinesin quantity, we found that the ratios of the amounts of clinorotated/stationary KLPs decreased from clinorotation day 5 to day 10, although it increased on days 2 and 3. Immunofluorescence analysis revealed that kinesin in the nucleus was the first to be affected by simulated microgravity, following the kinesin at the periphery that was affected at various times during clinorotation. Real-time RT-PCR analysis of kinesin mRNA expression was performed and led to the identification of 3 microgravity-sensitive kinesin genes: KIF9, KIFC1, and KIF21A. Our results suggest that kinesin has a distinct expression pattern, and the identification of microgravity-sensitive kinesin genes offers insight into fundamental cell biology.

Ni, Chengzhi; Wang, Chunyan; Li, Yuan; Li, Yinghui; Dai, Zhongquan; Zhao, Dongming; Sun, Hongyi; Wu, Bin

2011-06-01

262

An animal component free medium that promotes the growth of various animal cell lines for the production of viral vaccines.  

PubMed

IPT-AFM is a proprietary animal component free medium that was developed for rabies virus (strain LP 2061) production in Vero cells. In the present work, we demonstrated the versatility of this medium and its ability to sustain the growth of other cell lines and different virus strains. Here, three models were presented: Vero cells/rabies virus (strain LP 2061), MRC-5 cells/measles virus (strain AIK-C) and BHK-21 cells/rabies virus (strain PV-BHK21). The cell lines were first adapted to grow in IPT-AFM, by progressive reduction of the amount of serum in the culture medium. After their adaptation, BHK-21 cells grew in suspension by forming clumps, whereas MRC-5 cells remained adherent. Then, kinetics of cell growth were studied in agitated cultures for both cell lines. In addition, kinetics of virus replication were investigated. PMID:24583007

Rourou, Samia; Ben Ayed, Yousr; Trabelsi, Khaled; Majoul, Samy; Kallel, Héla

2014-05-19

263

Human sepsis-associated Escherichia coli (SEPEC) is able to adhere to and invade kidney epithelial cells in culture.  

PubMed

The adhesins of extraintestinal pathogenic Escherichia coli are essential for mediating direct interactions between the microbes and the host cell surfaces that they infect. Using fluorescence microscopy and gentamycin protection assays, we observed that 49 sepsis-associated E. coli (SEPEC) strains isolated from human adults adhered to and invaded Vero cells in the presence of D-mannose (100%). In addition, bacteria concentrations of approximately 2 x 10(7) CFU/mL were recovered from Vero cells following an invasion assay. Furthermore, PCR analysis of adhesin genes showed that 98.0% of these SEPEC strains tested positive for fimH, 69.4% for flu, 53.1% for csgA, 38.8% for mat, and 32.7% for iha. Analysis of the invasin genes showed that 16.3% of the SEPEC strains were positive for tia, 12.3% for gimB, and 10.2% for ibeA. Therefore, these data suggest that SEPEC adhesion to cell surfaces occurs through non-fimH mechanisms. Scanning electron microscopy showed the formation of microcolonies on the Vero cell surface. SEPEC invasiveness was also confirmed by the presence of intracellular bacteria, and ultrastructural analysis using electron transmission microscopy revealed bacteria inside the Vero cells. Taken together, these results demonstrate that these SEPEC strains had the ability to adhere to and invade Vero cells. Moreover, these data support the theory that renal cells may be the predominant pathway through which SEPEC enters human blood vessels. PMID:22488222

Conceição, R A; Ludovico, M S; Andrade, C G T J; Yano, T

2012-05-01

264

Identity of succinate dehydrogenase in chemotrophically and phototrophically grown Rhodospirillum rubrum  

Microsoft Academic Search

The specific succinate dehydrogenase (EC 1.3.99.1 succinate: phenazine methosulfate oxidoreductase) activity of membranes of aerobically grown Rhodospirillum rubrum was found to be 4–7-fold greater than that of membranes from phototrophically grown cells. The enzymes obtained from cells grown under both conditions were compared in crossed immunoelectrophoresis and were shown to have the same electrophoretic mobility and immunological identity. As succinate

Mary Lynne Perille Collins; Carrie A. Norton Hughes

1983-01-01

265

Characterization of Junin arenavirus cell entry  

Microsoft Academic Search

Junin virus (JUNV) entry is conducted by receptor-mediated endocytosis. To explore the cellular entry mechanism of JUNV, inhibitory effects of drugs affecting the main endocytic pathways on JUNV entry into Vero cells were analysed. Compounds that impair clathrin-mediated endocytosis were shown to reduce virus internalization without affecting virion binding. In contrast, drugs that alter lipid-raft microdomains, impairing caveola-mediated endocytosis, were

M. Guadalupe Martinez; Sandra M. Cordo; Nelida A. Candurra

2007-01-01

266

Floc Formation by Azospirillum lipoferum Grown on Poly-?-Hydroxybutyrate †  

PubMed Central

Azospirillum lipoferum RG6xx was grown under conditions similar to those resulting in encystment of Azotobacter spp. A. lipoferum produced cells of uniform shape when grown on nitrogen-free ?-hydroxybutyrate agar. Cells accumulated poly-?-hydroxybutyrate and often grew as chains or filaments that eventually lost motility and formed capsules. Within 1 week, vegetative A. lipoferum inocula were converted into microflocs arising from filaments or chains. Cells within microflocs were pleomorphic, contained much poly-?-hydroxybutyrate, and were encapsulated. Some cells had a cystlike morphology. Up to 57% of the dry weight of encapsulated flocs was poly-?-hydroxybutyrate, whereas vegetative cells grown in broth with combined nitrogen had only 3% of their dry weight as poly-?-hydroxybutyrate. Neither encapsulated cells in flocs nor nonencapsulated vegetative cells were significantly desiccation resistant. Under starvation conditions (9 days) only 25% of encapsulated cells remained viable, whereas vegetative cells multiplied severalfold. In short-term germination experiments with encapsulated flocs, nitrate, ammonium, and soil extract promoted formation of motile vegetative cells. Most cells in treatments lacking combined nitrogen eventually depleted their visible poly-?-hydroxybutyrate reserves without germinating. The remaining cells retained the reserve polymer and underwent size reduction. Images PMID:16347792

Bleakley, Bruce H.; Gaskins, Murray H.; Hubbell, David H.; Zam, Stephan G.

1988-01-01

267

Effect of spacer layer thickness on multi-stacked InGaAs quantum dots grown on GaAs (311)B substrate for application to intermediate band solar cells  

SciTech Connect

We have investigated the properties of multi-stacked layers of self-organized In{sub 0.4}Ga{sub 0.6}As quantum dots (QDs) on GaAs (311)B grown by molecular beam epitaxy. We found that a high degree of in-plane ordering of QDs structure with a six-fold symmetry was maintained though the growth has been performed at a higher growth rate than the conventional conditions. The dependence of photoluminescence characteristics on spacer layer thickness showed an increasing degree of electronic coupling between the stacked QDs for thinner spacer layers. The external quantum efficiency for an InGaAs/GaAs quantum dot solar cell (QDSC) with a thin spacer layer thickness increased in the longer wavelength range due to additive contribution from QD layers inserted in the intrinsic region. Furthermore, a photocurrent production by 2-step photon absorption has been observed at room temperature for the InGaAs/GaAs QDSC with a spacer layer thickness of 15 nm.

Shoji, Yasushi [Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Narahara, Kohei; Okada, Yoshitaka [Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Tanaka, Hideharu; Kita, Takashi [Department of Electrical and Electronics Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan); Akimoto, Katsuhiro [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

2012-04-01

268

Porcine platelet lysate as a supplement for animal cell culture  

Microsoft Academic Search

A novel supplementation of cell growth media based on a porcine platelet lysate was developed for culture of animal-derived\\u000a cells. The platelet lysate was produced from porcine blood and contained lysate of platelets and plasma components. It showed\\u000a satisfactory microbiological integrity and it carried only low amount of endotoxins (<10 EU\\/mL). The porcine platelet lysate\\u000a supported well proliferation of Vero (African

Anna Aldén; Lorena Gonzalez; Anna Persson; Kerstin Christensson; Olov Holmqvist; Sten Ohlson

2007-01-01

269

Nucleolus in clinostat-grown plants  

SciTech Connect

The clinostat is an apparatus that is used to mimic zero gravity in studies of plant growth in the absence of gravitropic response. Clinostat-grown tissue cultures of carrot exhibit significant increases both in the number of nuclei containing more than one nucleolus and in nucleolar volume. Oat seedlings germinated and grown on clinostats exhibit a decreased rate of shoot elongation, increased tissue sensitivity to applied auxin, and an increased response to gravitropic stimulation. Clinostat treatment clearly affects plant metabolism. The nucleolus is the region in the nucleus where ribosome synthesis and assembly take place. The 18S, 5.8S, and 25S ribosomal genes, in tandem units, are located in the nucleolus. Ribosomes orchestrate the production of all proteins that are necessary for the maintenance of cell growth, development, and survival. A full study of the effects of nullification of gravitropism, by clinostat rotation, on nucleolar development in barley has been initiated. The authors study developmental changes of nucleolar number and diameter in clinostat-grown root tissues. Preliminary results show that barley roots exhibit changes in nucleolar number and diameter. Growth rates of barley root and shoot also appear to be reduced, in measurements of both length and weight.

Shen-Miller, J.; Dannenhoffer, J. (Univ. of California, Los Angeles (United States)); Hinchman, R. (Argonne National Lab., IL (United States))

1991-05-01

270

Evidence that an internal carbonic anhydrase is present in 5% CO/sub 2/-grown and air-grown Chlamydomonas. [Chlamydomonas reinhardtii  

SciTech Connect

Inorganic carbon (C/sub i/) uptake was measured in wild-type cells of Chlamydomonas reinhardtii, and in cia-3, a mutant strain of C. reinhardtii that cannot grow with air levels of CO/sub 2/. Both air-grown cells, that have a CO/sub 2/ concentrating system, and 5% CO/sub 2/-grown cells that do not have this system, were used. When the external pH was 5.1 or 7.3, air-grown, wild-type cells accumulated inorganic carbon (C/sub i/) and this accumulation was enhanced when the permeant carbonic anhydrase inhibitor, ethoxyzolamide, was added. When the external pH was 5.1, 5% CO/sub 2/-grown cells also accumulated some C/sub i/, although not as much as air-grown cells and this accumulation was stimulated by the addition of ethoxyzolamide. At the same time, ethoxyzolamide inhibited CO/sub 2/ fixation by high CO/sub 2/-grown, wild-type cells at both pH 5.1 and 7.3. These observations imply that 5% CO/sub 2/-grown, wild-type cells, have a physiologically important internal carbonic anhydrase, although the major carbonic anhydrase located in the periplasmic space is only present in air-grown cells. Inorganic carbon uptake by cia-3 cells supported this conclusion. This mutant strain, which is thought to lack an internal carbonic anhydrase, was unaffected by ethoxyzolamide at pH 5.1. Other physiological characteristics of cia-3 resemble those of wild-type cells that have been treated with ethoxyzolamide. It is concluded that an internal carbonic anhydrase is under different regulatory control than the periplasmic carbonic anhydrase.

Moroney, J.V.; Togasaki, R.K.; Husic, H.D.; Tolbert, N.E.

1987-07-01

271

Authentication of African green monkey cell lines using human short tandem repeat markers  

PubMed Central

Background Tools for authenticating cell lines are critical for quality control in cell-based biological experiments. Currently there are methods to authenticate human cell lines using short tandem repeat (STR) markers based on the technology and procedures successfully used in the forensic community for human identification, but there are no STR based methods for authenticating nonhuman cell lines to date. There is significant homology between the human and vervet monkey genome and we utilized these similarities to design the first multiplex assay based on human STR markers for vervet cell line identification. Results The following STR markers were incorporated into the vervet multiplex PCR assay: D17S1304, D5S1467, D19S245, D1S518, D8S1106, D4S2408, D6S1017, and DYS389. The eight markers were successful in uniquely identifying sixty-two vervet monkey DNA samples and confirmed that Vero76 cells and COS-7 cells were derived from Vero and CV-1 cells, respectively. The multiplex assay shows specificity for vervet DNA within the determined allele range for vervet monkeys; however, the primers will also amplify human DNA for each marker resulting in amplicons outside the vervet allele range in several of the loci. The STR markers showed genetic stability in over sixty-nine passages of Vero cells, suggesting low mutation rates in the targeted STR sequences in the Vero cell line. Conclusions A functional vervet multiplex assay consisting of eight human STR markers with heterozygosity values ranging from 0.53-0.79 was successful in uniquely identifying sixty-two vervet monkey samples. The probability of a random match using these eight markers between any two vervet samples is approximately 1 in 1.9 million. While authenticating a vervet cell line, the multiplex assay may also be a useful indicator for human cell line contamination since the assay is based on human STR markers. PMID:22059503

2011-01-01

272

Fatty Acid Composition of Cladosporium resinae Grown on Glucose and on Hydrocarbons  

PubMed Central

Cladosporium resinae was grown in submerged cultures on glucose; on Jet-A commercial aviation fuel; and on a series of n-alkanes, n-decane through n-tetradecane. Cell yield was greatest on glucose and least on Jet-A; n-alkanes were intermediate. Among n-alkanes cell yield decreased as chain length increased, except for n-dodecane, which supported less growth than n-tridecane or n-tetradecane. The total fatty acids of stationary-phase cells were analyzed by gas-liquid chromatography. In all cases the predominant fatty acids were 16:0, 18:1, and 18:2. The fatty acid composition of glucose-grown cells was similar to that of hydrocarbon-grown cells. Cells grown on n-tridecane or n-tetradecane yielded small amounts of acids homologous to the carbon source, but a similar correlation was not noted for n-decane, n-undecane, or n-dodecane. Cells grown on n-undecane or n-tridecane contained more odd-carbon fatty acids than cells grown on the other substrates, and the effect was more pronounced in n-tridecane-grown cells. Thus, the fatty acids of this organism are derived chiefly from de novo synthesis rather than from direct incorporation of oxidized hydrocarbons. The extent of direct incorporation increases as the chain length of the hydrocarbon growth substrate is increased. PMID:5166858

Cooney, J. J.; Proby, C. M.

1971-01-01

273

Deletion of the S component inverted repeat sequence c ? and the nonessential genes U s 1 through U s 5 from the herpes simplex virus type 1 genome substantially impairs productive viral infection in cell culture and pathogenesis in the rat central nervous system  

Microsoft Academic Search

A distinctive feature of the genetic make-up of herpes simplex virus type 1 (HSV-1), a human neurotropic virus, is that approximately half of the 81 known viral genes are not absolutely required for productive infection in Vero cells, and most can be individually deleted without substantially impairing viral replication in cell culture. If large blocks of contiguous viral genes could

Siyamak Rasty; P Luigi Poliani; David J Fink; Joseph C Glorioso

1997-01-01

274

Avian reovirus influences phosphorylation of several factors involved in host protein translation including eukaryotic translation elongation factor 2 (eEF2) in Vero cells  

Microsoft Academic Search

Viral infection usually influences cellular protein synthesis either actively or passively via modification of various translation initiation factors. Here we demonstrated that infection with avian reovirus (ARV) interfered with cellular protein synthesis. This study demonstrated for the first time that ARV influenced the phosphorylation of translation initiation factors including eIF4E and eIF-4G. Interestingly, ARV also induced phosphorylation of eukaryotic translation

Wen T. Ji; Lai Wang; Ru C. Lin; Wei R. Huang; Hung J. Liu

2009-01-01

275

Bioengineered Dental Tissues Grown in the Rat Jaw  

Microsoft Academic Search

Our long-term objective is to develop methods to form, in the jaw, bioengineered replacement teeth that exhibit physical properties and functions similar to those of natural teeth. Our results show that cultured rat tooth bud cells, seeded onto biodegradable scaffolds, implanted into the jaws of adult rat hosts and grown for 12 weeks, formed small, organized, bioengineered tooth crowns, containing

S. E. Duailibi; M. T. Duailibi; W. Zhang; R. Asrican; J. P. Vacanti; P. C. Yelick

2008-01-01

276

Nuclear factor of activated T-cells (NFAT) plays a role in SV40 infection  

SciTech Connect

Recent evidence highlighted a role for the transcription factor, nuclear factor of activated T-cells (NFAT), in the transcription of the human polyomavirus JCV. Here we show that NFAT is also important in the transcriptional control of the related polyomavirus, Simian Virus 40 (SV40). Inhibition of NFAT activity reduced SV40 infection of Vero, 293A, and HeLa cells, and this block occurred at the stage of viral transcription. Both NFAT3 and NFAT4 bound to the SV40 promoter through {kappa}B sites located within the 72 bp repeated enhancer region. In Vero cells, NFAT was involved in late transcription, but in HeLa and 293A cells both early and late viral transcription required NFAT activity. SV40 large T-Ag was found to increase NFAT activity and provided a positive feedback loop to transactivate the SV40 promoter.

Manley, Kate [Graduate Program in Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912 (United States); O'Hara, Bethany A. [Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912 (United States); Atwood, Walter J. [Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912 (United States)], E-mail: Walter_Atwood@Brown.edu

2008-03-01

277

Growth of the Phlebovirus Toscana in a mosquito (Aedes pseudoscutellaris) cell line (AP61): Establishment of a persistent infection  

Microsoft Academic Search

Summary Toscana Virus, a sandfly-associatedPhlebovirus, was adapted to grow in culturedAedes pseudoscutellaris (AP-61) mosquito cell line. No evidence of virus growth was seen after primary infection of cell monolayers under maintenance conditions. On the contrary, persistent infections were established by subculturing infected cultures. Cytopathic effect was never observed. Significant titres of virus (103–105 PFU\\/ml), as assayed in Vero cells at

L. Nicoletti; Paola Verani

1985-01-01

278

Tissue grown in space in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, such as the culture section shown here, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. The two white circles within the tumor are part of a plastic lattice that helped the cells associate. 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). 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.

1998-01-01

279

Impact of Host Cell Line Adaptation on Quasispecies Composition and Glycosylation of Influenza A Virus Hemagglutinin  

PubMed Central

The genome of influenza A viruses is constantly changing (genetic drift) resulting in small, gradual changes in viral proteins. Alterations within antibody recognition sites of the viral membrane glycoproteins hemagglutinin (HA) and neuraminidase (NA) result in an antigenetic drift, which requires the seasonal update of human influenza virus vaccines. Generally, virus adaptation is necessary to obtain sufficiently high virus yields in cell culture-derived vaccine manufacturing. In this study detailed HA N-glycosylation pattern analysis was combined with in-depth pyrosequencing analysis of the virus genomic RNA. Forward and backward adaptation from Madin-Darby Canine Kidney (MDCK) cells to African green monkey kidney (Vero) cells was investigated for two closely related influenza A virus PR/8/34 (H1N1) strains: from the National Institute for Biological Standards and Control (NIBSC) or the Robert Koch Institute (RKI). Furthermore, stability of HA N-glycosylation patterns over ten consecutive passages and different harvest time points is demonstrated. Adaptation to Vero cells finally allowed efficient influenza A virus replication in Vero cells. In contrast, during back-adaptation the virus replicated well from the very beginning. HA N-glycosylation patterns were cell line dependent and stabilized fast within one (NIBSC-derived virus) or two (RKI-derived virus) successive passages during adaptation processes. However, during adaptation new virus variants were detected. These variants carried “rescue” mutations on the genomic level within the HA stem region, which result in amino acid substitutions. These substitutions finally allowed sufficient virus replication in the new host system. According to adaptation pressure the composition of the virus populations varied. In Vero cells a selection for “rescue” variants was characteristic. After back-adaptation to MDCK cells some variants persisted at indifferent frequencies, others slowly diminished and even dropped below the detection limit. PMID:22163276

Roedig, Jana Verena; Rapp, Erdmann; Hoper, Dirk; Genzel, Yvonne; Reichl, Udo

2011-01-01

280

Thermal Stability of Corrugated Epitaxial Graphene Grown on Re(0001)  

NASA Astrophysics Data System (ADS)

We report on a novel approach to determine the relationship between the corrugation and the thermal stability of epitaxial graphene grown on a strongly interacting substrate. According to our density functional theory calculations, the C single layer grown on Re(0001) is strongly corrugated, with a buckling of 1.6 Å, yielding a simulated C 1s core level spectrum which is in excellent agreement with the experimental one. We found that corrugation is closely knit with the thermal stability of the C network: C-C bond breaking is favored in the strongly buckled regions of the moiré cell, though it requires the presence of diffusing graphene layer vacancies.

Miniussi, E.; Pozzo, M.; Baraldi, A.; Vesselli, E.; Zhan, R. R.; Comelli, G.; Mente?, T. O.; Niño, M. A.; Locatelli, A.; Lizzit, S.; Alfè, D.

2011-05-01

281

Characteristics of Nipah virus and Hendra virus replication in different cell-lines and their suitability for anti-viral screening  

PubMed Central

We have recently described the development and validation of a High Throughput Screening assay suitable for Henipavirus antiviral identification. While we are confident this assay is robust and effective, we wished to investigate assay performance in a range of alternative cell lines to determine if assay sensitivity and specificity could be improved. We evaluated ten different cell lines for their susceptibility to Hendra and Nipah virus infection and their sensitivity of detection of the effects of the broad spectrum antiviral, ribavirin and nine novel antivirals identified using our initial screening approach. Cell lines were grouped into three categories with respect to viral replication. Virus replicated best in Vero and BSR cells, followed by Hep2, HeLa, BHK-21 and M17 cells. The lowest levels of RNA replication and viral protein expression were observed in BAEC, MMEC, A549 and ECV304 cells. Eight cell lines appeared to be similarly effective at discriminating the antiviral effects of ribavirin (<2.7 fold difference). The two cells lines most sensitive to the effect of ribavirin (ECV304 and BAEC) also displayed the lowest levels of viral replication while Vero cells were the least sensitive suggesting excess viral replication may limit drug efficacy and cell lines which limit viral replication may result in enhanced antiviral efficacy. However, there was no consistent trend observed with the other nine antivirals tested. While improvements in antiviral sensitivity in other cell lines may indicate an important role in future HTS assays, the slightly lower sensitivity to antiviral detection in Vero cells has inherent advantages in reducing the number of partially effective lead molecules identified during initial screens. Comparison of a panel of 54 novel antiviral compounds identified during routine screening of an in-house compound library in Vero, BHK-21 and BSR cells suggests no clear advantage of screening in either cell type. PMID:19428741

Aljofan, Mohamad; Saubern, Simon; Meyer, Adam G.; Marsh, Glenn; Meers, Joanne; Mungall, Bruce A.

2009-01-01

282

Enhanced capacity of DNA repair in human cytomegalovirus-infected cells  

SciTech Connect

Plaque formation in Vero cells by UV-irradiated herpes simplex virus was enhanced by infection with human cytomegalovirus (HCMV), UV irradiation, or treatment with methylmethanesulfonate. Preinfection of Vero cells with HCMV enhanced reactivation of UV-irradiated herpes simplex virus more significantly than did treatment with UV or methylmethanesulfonate alone. A similar enhancement by HCMV was observed in human embryonic fibroblasts, but not in xeroderma pigmentosum (XP12BE) cells. It was also found that HCMV infection enhanced hydroxyurea-resistant DNA synthesis induced by UV light or methylmethanesulfonate. Alkaline sucrose gradient sedimentation analysis revealed an enhanced rate of synthesis of all size classes of DNA in UV-irradiated HCMV-infected Vero cells. However, HCMV infection did not induce repairable lesions in cellular DNA and did not significantly inhibit host cell DNA synthesis, unlike UV or methylmethanesulfonate. These results indicate that HCMV enhanced DNA repair capacity in the host cells without producing detectable lesions in cellular DNA and without inhibiting DNA synthesis. This repair appeared to be error proof for UV-damaged herpes simplex virus DNA when tested with herpes simplex virus thymidine kinase-negative mutants.

Nishiyama, Y.; Rapp, F.

1981-04-01

283

Fast Plants Grown in Light and Dark  

NSDL National Science Digital Library

Photograph of two five-day-old Standard Fast Plants grown in Bottle Growing Systems--one grown with full light, one grown in the dark. This is a good example of a quick way to stimulate discussion about the matter and energy sources and needs that germinating seeds have in comparison to seedlings or plants.

Lauffer, Hedi B.

284

Sulfated proteoglycan synthesis by confluent cultures of rabbit costal chondrocytes grown in the presence of fibroblast growth factor  

Microsoft Academic Search

We examined the effect of fibroblast growth factor (FGF) on proteoglycan synthesis by rabbit costal chondrocyte cultures maintained on plastic tissue culture dishes. Low density rabbit costal chondrocyte cultures grown in the absence of FGF gave rise at confluency to a heterogeneous cell population composed of fibroblastic cells and poorly differentiated chon- drocytes. When similar cultures were grown in the

YUKIO KATO; DENIS GOSPODAROWICZ

1985-01-01

285

High-efficiency solar cells fabricated from direct-current magnetron sputtered n-indium tin oxide onto p-InP grown by atmospheric pressure metalorganic vapor phase epitaxy  

NASA Technical Reports Server (NTRS)

An attempt is made to improve device efficiencies by depositing indium tin oxide onto epitaxially grown p-InP on p(+)-InP substrates. This leads to a reduction in the device series resistance, high-quality reproducible surfaces, and an improvement in the transport properties of the base layer. Moreover, many of the facets associated with badly characterized bulk liquid encapsulated Czochralski substrates used in previous investigations are removed in this way.

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

1989-01-01

286

Antibacterial effect of theaflavin, polyphenon 60 (Camellia sinensis) and Euphorbia hirta on Shigella spp.--a cell culture study.  

PubMed

Antibacterial effect of compounds extracted from Camellia sinensis L. and the methanol extract of Euphorbia hirta L. were studied against dysentery causing Shigella spp. using the Vero cell line. Cytotoxicity studies of the extracts were performed using the cell line and the non-cytotoxic concentration of the extract was tested for antibacterial activity against the cytopathic dose of the pathogen. These extracts were found to be non-cytotoxic and effective antibacterial agents. PMID:8847884

Vijaya, K; Ananthan, S; Nalini, R

1995-12-01

287

Increased ultraviolet radiation sensitivity of Escherichia coli grown at low temperature.  

PubMed

The repair of DNA damage caused by ultraviolet radiation (UVR) is well understood in both lower and higher organisms. Genetic studies carried out at optimum temperature for growth, 37 °C in Escherichia coli, have revealed the major pathways of DNA repair. We show that E. coli cells grown at 20 °C are more sensitive to UVR than cells grown at 37 °C. The analysis of knockout mutants demonstrates that cells impaired in recombinational DNA repair pathways show increased UV sensitivity at 20 °C. Cells with mutations in the nucleotide excision repair (NER) pathway genes are highly sensitive to UVR when grown at 37 °C and retain that sensitivity when grown at 20 °C, whereas wild-type cells are not sensitive when grown at 37 °C but become more sensitive to UVR when grown at low temperatures. Our results taken along with reports from the literature suggest that the UVR sensitivity of E. coli cells at low temperature could be due to impaired NER function. PMID:24802940

Mangoli, Suhas; Rath, Devashish; Goswami, Manish; Jawali, Narendra

2014-05-01

288

Variations of two pools of glycogen and carbohydrate in Saccharomyces cerevisiae grown with various ethanol concentrations.  

PubMed

Glycogen, a major reservoir of energy in Saccharomyces cerevisiae, is found to be present as soluble and membrane-bound insoluble pools. Yeast cells can store excess glycogen when grown in media with higher concentration of sugar or when subjected to nutritional stress conditions. Saccharomyces cerevisiae NCIM-3300 was grown in media having ethanol concentrations up to 12% (v/v). The effects of externally added ethanol on glycogen and other carbohydrate content of yeast were studied by using alkali digestion process. Fermentative activities of cells grown in the presence of various ethanol concentrations (2-8% v/v) exhibited increase in values of glycogen and other carbohydrate, whereas cells grown with higher concentrations of ethanol (10-12% v/v) exhibited depletion in glycogen and carbohydrate content along with decrease in cell weight. Such inhibitory effect of ethanol was also exhibited in terms of reduction in total cell count of yeast grown in media with 2-16% (v/v) ethanol and 8% (w/v) sugar. These data suggest that, as the plasma membrane is a prime target for ethanol action, membrane-bound insoluble glycogen might play a protective role in combating ethanol stress. Elevated level of cell-surface alpha-glucans in yeast grown with ethanol, as measured by using amyloglucosidase treatment, confirms the correlation between ethanol and glycogen. PMID:20373126

Dake, M S; Jadhv, J P; Patil, N B

2010-07-01

289

PER.C6(®) cells as a serum-free suspension cell platform for the production of high titer poliovirus: a potential low cost of goods option for world supply of inactivated poliovirus vaccine.  

PubMed

There are two highly efficacious poliovirus vaccines: Sabin's live-attenuated oral polio vaccine (OPV) and Salk's inactivated polio vaccine (IPV). OPV can be made at low costs per dose and is easily administrated. However, the major drawback is the frequent reversion of the OPV vaccine strains to virulent poliovirus strains which can result in Vaccine Associated Paralytic Poliomyelitis (VAPP) in vaccinees. Furthermore, some OPV revertants with high transmissibility can circulate in the population as circulating Vaccine Derived Polioviruses (cVDPVs). IPV does not convey VAPP and cVDPVs but the high costs per dose and insufficient supply have rendered IPV an unfavorable option for low and middle-income countries. Here, we explored whether the human PER.C6(®) cell-line, which has the unique capability to grow at high density in suspension, under serum-free conditions, could be used as a platform for high yield production of poliovirus. PER.C6(®) cells supported replication of all three poliovirus serotypes with virus titers ranging from 9.4 log(10) to 11.1 log(10)TCID(50)/ml irrespective of the volume scale (10 ml in shaker flasks to 2 L in bioreactors). This production yield was 10-30 fold higher than in Vero cell cultures performed here, and even 100-fold higher than what has been reported for Vero cell cultures in literature [38]. In agreement, the D-antigen content per volume PER.C6(®)-derived poliovirus was on average 30-fold higher than Vero-derived poliovirus. Interestingly, PER.C6(®) cells produced on average 2.5-fold more D-antigen units per cell than Vero cells. Based on our findings, we are exploring PER.C6(®) as an interesting platform for large-scale production of poliovirus at low costs, potentially providing the basis for global supply of an affordable IPV. PMID:23123018

Sanders, Barbara P; Edo-Matas, Diana; Custers, Jerome H H V; Koldijk, Martin H; Klaren, Vincent; Turk, Marije; Luitjens, Alfred; Bakker, Wilfried A M; Uytdehaag, Fons; Goudsmit, Jaap; Lewis, John A; Schuitemaker, Hanneke

2013-01-21

290

Antimycotic-Antibiotic Amphotericin B Promotes Influenza Virus Replication in Cell Culture ?  

PubMed Central

In general, antibiotics are not rated as substances that inhibit or support influenza virus replication. We describe here the enhancing effect of the polyene antibiotic amphotericin B (AmB) on influenza virus growth in Vero cells. We show that isolation rates of influenza A and B viruses from clinical samples can be dramatically enhanced by adding AmB to the culture medium. We demonstrate that AmB promotes the viral uptake and endocytic processing of the virus particles. This effect is specific for Vero and human nasal epithelial cells and was not observed in Madin-Darby canine kidney cells. The effect of AmB was subtype specific and more prominent for human seasonal influenza strains but absent for H5N1 human viruses. The AmB-enhancing effect seemed to be solely due to the viral hemagglutinin function. Our results indicate that the use of AmB may facilitate influenza virus isolation and production in Vero cells. PMID:21849438

Roethl, Elisabeth; Gassner, Manuela; Krenn, Brigitte M.; Romanovskaya-Romanko, Ekaterina A.; Seper, Helena; Romanova, Julia; Nakowitsch, Sabine; Sturlan, Sanda; Wolschek, Markus; Sirotkin, Alexej; Kiselev, Oleg; Muster, Thomas; Egorov, Andrej

2011-01-01

291

Strain Variation in Glycosaminoglycan Recognition Influences Cell-Type-Specific Binding by Lyme Disease Spirochetes  

Microsoft Academic Search

Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown to bind glycosamino- glycans (GAGs). In the current study, the GAG-binding properties of eight Lyme disease strains were deter- mined. Binding by two high-passage HB19 derivatives to Vero cells could not

NIKHAT PARVEEN; DOUGLAS ROBBINS; JOHN M. LEONG

1999-01-01

292

Listeria monocytogenes Grown at 7?C Shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes Grown at 37?C  

PubMed Central

Survival of the food-borne pathogen Listeria monocytogenes in acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affects L. monocytogenes survival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C). L. monocytogenes cells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). For L. monocytogenes grown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response of L. monocytogenes grown to log phase at 37°C involved stress-related transcriptional regulators (i.e., ?B, ?H, CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability of L. monocytogenes to survive gastric passage and ultimately cause disease. PMID:22447604

Ivy, R. A.; Wiedmann, M.

2012-01-01

293

Films Grown on Silicon Substrate  

NASA Astrophysics Data System (ADS)

The effect of thickness and annealing temperature on magnetic properties of ultrathin ?-Fe2O3 films with MgO buffer layer grown on silicon substrate is investigated. The saturation magnetization and coercive force of samples at room temperature increase with increasing of annealing temperature, and decrease as annealing temperature is above 873 K (600 °C). The saturation magnetization of samples decreases with increasing of the thickness of ?-Fe2O3 at room temperature. The samples with 3 to 4 nm thick ?-Fe2O3 annealed at 873 K (600 °C) show saturation magnetization of about 400 emu/cm3, which is close to the bulk value of ~390 emu/cm3 within the error range.

Sun, Bai; Zhao, Wenxi; Xiong, Yuanqiang; Lin, Yingyan; Chen, Peng

2014-10-01

294

Nucleolus in clinostat-grown plants  

Microsoft Academic Search

The clinostat is an apparatus that is used to mimic zero gravity in studies of plant growth in the absence of gravitropic response. Clinostat-grown tissue cultures of carrot exhibit significant increases both in the number of nuclei containing more than one nucleolus and in nucleolar volume. Oat seedlings germinated and grown on clinostats exhibit a decreased rate of shoot elongation,

J. Shen-Miller; J. Dannenhoffer; R. Hinchman

1991-01-01

295

Characterization of Si(100) homoepitaxy grown in the STM at low temperatures  

SciTech Connect

We explore the growth of low-temperature bulk-like Si(100) homoepitaxy with regard to microscopic surface roughness and defects We characterize films grown at different temperatures up to 500K in-situ by means of an effusion cell added to our UHVSTM. The development of novel architectures for future generation computers calls for high-quality homoepitaxial (WOO) grown at low temperature. Even though Si(100) can be grown crystalline up to a limited thickness: the microstructure reveals significant small-scale surface roughness and defects specific to low-temperature growth. Both can he detrimental to fabrication and operation of small-scale electronic devices.

Grube, H. (Holger); Brown, G. W. (Geoffrey W.); Pomeroy, J. M. (Joshua M.); Hawley, M. E. (Marilyn E.)

2002-01-01

296

Insulin-like growth factor (IGF)-I and -II and IGFBP secretion by ovine satellite cell strains grown alone or in coculture with 3T3-L1 preadipocytes  

Microsoft Academic Search

Summary  The current study was designed to examine the effects of muscle and fat stem cell coculture on the secretion of insulinlike\\u000a growth factor (IGF)-I and -II and IGF binding proteins (IGFBP) by these cells. Two sheep satellite cell strains with negligible\\u000a or high potential for differentiation (10A and 01, respectively) were placed in coculture with 3T3-L1 preadipocytes using a filter

K. L. Hossner; R. Yemm; J. Vierck; M. V. Dodson

1997-01-01

297

Respiratory Development in Saccharomyces cerevisiae Grown at Controlled Oxygen Tension  

PubMed Central

Saccharomyces cerevisiae was grown in batch culture over a wide range of oxygen concentrations, varying from the anaerobic condition to a maximal dissolved oxygen concentration of 3.5 ?M. The development of cells was assayed by measuring amounts of the aerobic cytochromes aa3, b, c, and c1, the cellular content of unsaturated fatty acids and ergosterol, and the activity of respiratory enzyme complexes. The half-maximal levels of membrane-bound cytochromes aa3, b, and c1, were reached in cells grown in O2 concentrations around 0.1 ?M; this was similar to the oxygen concentration required for half-maximal levels of unsaturated fatty acid and sterol. However, the synthesis of ubiquinone and cytochrome c and the increase in fumarase activity were essentially linear functions of the dissolved oxygen concentration up to 3.5 ?M oxygen. The synthesis of the succinate dehydrogenase, succinate cytochrome c reductase, and cytochrome c oxidase complexes showed different responses to changes in O2 concentration in the growth medium. Cyanide-insensitive respiration and P450 cytochrome content were maximal at 0.25 ?M oxygen and declined in both more anaerobic and aerobic conditions. Cytochrome c peroxidase and catalase activities in cell-free homogenates were high in all but the most strictly anaerobic cells. PMID:4352179

Rogers, P. J.; Stewart, P. R.

1973-01-01

298

Effects of Background Zn Doping on the Performance of InGaAs/GaAsP Multiple Quantum Well Solar Cells Grown by a Planetary Metal Organic Vapor Phase Epitaxy Reactor  

NASA Astrophysics Data System (ADS)

The effects of background Zn doping on the performance of p-i-n GaAs solar cells with InGaAs/GaAsP multiple quantum wells (MQWs) in i-GaAs layer have been studied. The crystal growth was done by a planetary metalorganic vapor phase epitaxy (MOVPE) reactor. The background Zn doping, in an order of 1017 cm-3, degraded the solar cell efficiency by modifying the energy band diagram in a way that obstructed carrier transports. It was shown by calculation that the carrier transports across the MQWs region suffered from decrease in built-in electric field in absorber layers, leading to an efficiency loss by radiative and nonradiative recombinations. Consequently, the external quantum efficiency and the current density of a Zn-contaminated MQW solar cell were terribly poor. Reactor baking at 850 °C for 20 min seems to remove Zn residues effectively without noticeable effects on the succeeding growth of MQW solar cells. The InGaAs/GaAsP MQWs fabricated in the thermally cleaned reactor have shown a potential to extend the absorption edge of GaAs solar cells and to improve the efficiency of multi-junction solar cells by current matching. Therefore, the growth of InGaAs/GaAsP MQWs by planetary MOVPE reactors requires a careful treatment regarding the background doping issue.

Sodabanlu, Hassanet; Ma, Shaojun; Watanabe, Kentaroh; Sugiyama, Masakazu; Nakano, Yoshiaki

2012-10-01

299

Polymorphs of Rubrene Crystal Grown from Solution  

NASA Astrophysics Data System (ADS)

Single crystals of rubrene were grown by slow cooling of solutions in various solvents. Hexagonal single crystals were obtained from p-xylene, whereas parallelogram-shaped crystals were grown from aniline. Both types of crystal were obtained from propan-1-ol. Single-crystal X-ray diffraction analyses showed that the hexagonal and parallelogram-shaped crystals belonged to the orthorhombic system and the triclinic system, respectively. The triclinic crystals showed much poorer carrier mobilities than did the orthorhombic crystals.

Matsukawa, Takeshi; Yoshimura, Masashi; Uchiyama, Masahito; Yamagishi, Masakazu; Nakao, Akiko; Takahashi, Yoshinori; Takeya, Junichi; Kitaoka, Yasuo; Mori, Yusuke; Sasaki, Takatomo

2010-08-01

300

Cells  

NSDL National Science Digital Library

Students use websites to review about cells and cell processes. The Cell Look inside a cell The Virtual Cell Another inside view of a cell. Click on the worksheet. Cells of the body Look inside cells of the body Cells Flash cards Practice cell parts with functions. Cell Concentration Play concentration matching game. Cell Differentiation Movie Watch how cells change as an organism develops. Cell Organelle Table Review Cell Organelles Inside a Cell Look Inside a Cell Nobel Prize Educational Games Play games while learning about ...

Mcnees, Mrs.

2010-09-28

301

Improved xylanase production by Trichoderma reesei grown on l-arabinose and lactose or d-glucose mixtures  

Microsoft Academic Search

Trichoderma reesei Rut C-30 was grown on eight different natural or rare aldopentoses as the main carbon source and on mixtures of an aldopentose with d-glucose or lactose. The fungal cells consumed all aldopentoses tested, except l-xylose and l-ribose. The highest total xylanase and cellulase activities were achieved when cells were grown on l-arabinose as the main carbon source. The

H. Xiong; O. Turunen; O. Pastinen; M. Leisola; N. von Weymarn

2004-01-01

302

Fe(III) reduction activity and cytochrome content of Shewanella putrefaciens grown on ten compounds as sole terminal electron acceptor  

Microsoft Academic Search

Shewanella putrefaciens was grown on a series of ten alternate compounds as sole terminal electron acceptor. Each cell type was analyzed for Fe(III) reduction activity, absorbance maxima in reduced-minus-oxidized difference spectra and heme-containing protein content. High-rate Fe(III) reduction activity, pronounced difference maxima at 521 and 551 nm and a predominant 29.3 kDa heme-containing protein expressed by cells grown on Fe(III),

M. D. Blakeney; T. Moulaei; T. J. Dichristina

2000-01-01

303

Comparison Of LEC-Grown And VGF-Grown GaSb  

NASA Astrophysics Data System (ADS)

GaSb 2? diameter ingots doped with Tellurium have been grown by Vertical Gradient Freeze (VGF) on a (1 0 0) orientation. The ingots were grown in quartz crucibles with the use of an encapsulant and both 6 mm diameter and 50 mm diameter seeds. Twinning in the seed or in the cone of the crucible occurred in almost all cases when a 6 mm diameter seed was used, while using full-diameter (50 mm ID) seeds with a carefully controlled diameter resulted in single-crystal growth. The quality of the VGF-grown GaSb:Te from both 6 mm and full-diameter seeds has been compared to our commercially produced Liquid Encapsulated Czochralski (LEC) grown GaSb. The donor density and raman spectra of the VGF-grown GaSb are comparable to the electronic properties of LEC-grown GaSb, but slightly lower mobilities for the VGF-material are observed. The etch pit density (EPD) in VGF-grown GaSb from 6 mm diameter seeds is extremely low, around 5 per cm2. As expected the EPD of LEC-grown GaSb is significantly higher, due to the higher stress induced in the material during growth. Interestingly, the EPD for GaSb grown by VGF from full diameter seeds is comparable to the EPD from LEC-grown material. It is believed that seeding in VGF-growth induces stress and, therefore, a higher EPD. The use of small seeds ensures that dislocations can grow out. The crystal quality of the three materials is compared by comparing the X-ray rocking curves. LEC-grown GaSb and VGF-grown GaSb from full-diameter and 6 mm diameter seeds show a FWHM of 14.6, 15.1, and 20.7 arcsec, respectively.

Reijnen, L.; Brunton, R.; Grant, I. R.

2004-11-01

304

Some karyological observations on plants grown in space  

NASA Technical Reports Server (NTRS)

Experiments were conducted to assess whether cell division in a plant root would be affected by prolonged exposure to microgravity. Root materials from sunflower, oat, and mung bean plants grown on STS-2 and STS-3 were utilized for the experiments. It is found that all oat, sunflower, and mung seedlings showed a reduced number of cells in division as they went through their first cell division cycle on earth when compared to their ground controls. A significant number of oat, mung, and sunflower plantlets exhibited random root orientation and the lack of strictly orthotropic growth of their shoot systems in the flight samples. In addition, it is found that the mung roots were apparently least affected in terms of their cytology despite the fact that their roots were often randomly oriented.

Krikorian, A. D.; Oconnor, S. A.

1982-01-01

305

N/p InP (Indium Phosphides) Homojunction Solar Cells with an IN0.53GA0.47AS Contacting Layer Grown by Liquid Phase Epitaxy.  

National Technical Information Service (NTIS)

N/P InP homojunction solar cells with an In 0.53 Ga 0.47 As contacting layer were fabricated by liquid phase epitaxy (LPE). Electron-Beam-Induced-Current (EBIC) measurements were performed on several selected samples. It was found that the background dopi...

C. C. Shen, K. Y. Choi

1989-01-01

306

Human Colon Cancer Cells Cultivated in Space  

NASA Technical Reports Server (NTRS)

Within five days, bioreactor cultivated human colon cancer cells (shown) grown in Microgravity on the STS-70 mission in 1995, had grown 30 times the volume of the control specimens on Earth. The samples grown in space had a higher level of cellular organization and specialization. Because they more closely resemble tumors found in the body, microgravity grown cell cultures are ideal for research purposes.

1995-01-01

307

Rumen degradation of the rind part of normal and brown-midrib maizes grown at high and low temperature  

E-print Network

temperature had no drastic effect on cell wall composition, but cell walls from the plants grown at 18°C samples (+ 16 %), and not affected by the growth temperature, as neither was the cell wall disappearance of the growth temperature on CWdis was exactly the same as the effect of the bm3 mutation (+7 %). Scanning

Paris-Sud XI, Université de

308

A study on the long?term immunity induced by La Sota strain of Newcastle disease virus grown in a BS\\/BEK cell line of bovine embryo kidney origin  

Microsoft Academic Search

Twenty?day?old susceptible chickens were divided into three groups; two were vaccinated with inactivated, water in oil emulsified La Sota strain of Newcastle disease virus (NDV) obtained from a bovine embryo kidney (BS\\/BEK) cell line and from chicken embryos, respectively. The third unvaccinated group represented the control. At 30?day intervals subgroups were exposed to the Herts 33 virulent NDV strain. Serological

M. N. Losio; E. Lodetti; L. Alborali; G. Tosi; C. Buonavoglia

1998-01-01

309

Establishment of Fruit Bat Cells (Rousettus aegyptiacus) as a Model System for the Investigation of Filoviral Infection  

PubMed Central

Background The fruit bat species Rousettus aegyptiacus was identified as a potential reservoir for the highly pathogenic filovirus Marburg virus. To establish a basis for a molecular understanding of the biology of filoviruses in the reservoir host, we have adapted a set of molecular tools for investigation of filovirus replication in a recently developed cell line, R06E, derived from the species Rousettus aegyptiacus. Methodology/Principal Findings Upon infection with Ebola or Marburg viruses, R06E cells produced viral titers comparable to VeroE6 cells, as shown by TCID50 analysis. Electron microscopic analysis of infected cells revealed morphological signs of filovirus infection as described for human- and monkey-derived cell lines. Using R06E cells, we detected an unusually high amount of intracellular viral proteins, which correlated with the accumulation of high numbers of filoviral nucleocapsids in the cytoplasm. We established protocols to produce Marburg infectious virus-like particles from R06E cells, which were then used to infect naïve target cells to investigate primary transcription. This was not possible with other cell lines previously tested. Moreover, we established protocols to reliably rescue recombinant Marburg viruses from R06E cells. Conclusion/Significance These data indicated that R06E cells are highly suitable to investigate the biology of filoviruses in cells derived from their presumed reservoir. PMID:20808767

Krahling, Verena; Dolnik, Olga; Kolesnikova, Larissa; Schmidt-Chanasit, Jonas; Jordan, Ingo; Sandig, Volker; Gunther, Stephan; Becker, Stephan

2010-01-01

310

Use of digoxigenin-labelled oligonucleotide DNA probes for VT2 and VT2 human variant genes to differentiate Vero cytotoxin-producing Escherichia coli strains of serogroup O157.  

PubMed Central

Digoxigenin-labelled oligonucleotide DNA probes specific for B-subunit genes of Vero cytotoxin 2 (VT2) and a variant of VT2 (VT2vha) were used to differentiate 116 strains of Escherichia coli serogroup O157 belonging to phage types 1, 2, 4, 8, 14, and 49. Of these strains, 38% had sequences for both VT2 and VT2vha, 38% had sequences for VT2 only, and 24% had sequences for VT2vha only. Oligonucleotide probe hybridization subdivided strains of all of the phage types except phage type 1. The greatest variation in toxin gene pattern was observed with strains of phage type 14, for which there were six distinct patterns when the presence or absence of VT1 genes was also considered. Two strains from each phage type group were examined for bacteriophages encoding VT production. Two of the six VT2vha-producing strains carried phage from which DNA hybridized with the VT2vha-specific probe. Phages were not detected in the remaining four VT2vha strains, suggesting that genes may be chromosomally located or associated with a defective prophage. In contrast, seven of the eight VT2 strains carried phages from which DNA hybridized with the VT2-specific probe. Two strains of E32511 (O157:H-) were also investigated. One strain (E32511A) possessed gene sequences for both VT2 and VTvha and was shown to carry phage possessing gene sequences for VT2. With strain E32511B, however, phages were not detected and DNA hybridized only with the VT2vha probe. Analysis of total genomic DNA digested with restriction endonuclease EcoRI showed that polymorphisms were seen with VT2 strains and not with VT2vha strains. PMID:8102373

Thomas, A; Smith, H R; Rowe, B

1993-01-01

311

A synchronized cell suspension method for growing virus  

E-print Network

~ ~ ~ ~ ~ ~ . . ~ ~ ~ 10 21 ~ ~ ~ 47 VI BI BLIOGPAPHY ~ ~ ~ ~ ~ ~ ~ 70 VI TA ~ ~ ~ ~ ~ ~ ~ ~ ~ 77 IIST OZ TABLES Table Page Serum associated cytotoxic effect of thymidine and 5-AU on BHK-21 and Vero cells . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ 22 Mitotic values obtained...-growth-hormone system is a modifica- tion of that described by Daughaday and. Reeder (8). Healthy young rabbits 5-5 pounds were used for the pro- duction of the growth factor. All rabbits were pre- bled and the sera tested for cytotoxic or cytopathic factors on BHK...

Zuloaga Guillermo Gerardo

2012-06-07

312

Ion implanted epitaxially grown ZnSe  

NASA Technical Reports Server (NTRS)

The epitaxial growth of ZnSe on (100) Ge using the close-spaced transport process is described. Substrate temperature of 575 C and source temperatures of 675 C yield 10 micron, single crystal layers in 10 hours. The Ge substrates provides a nonreplenishable chemical transport agent and the epitaxial layer thickness is limited to approximately 10 microns. Grown epitaxial layers show excellent photoluminescence structure at 77 K. Grown layers exhibit high resistivity, and annealing in Zn vapor at 575 C reduces the resistivity to 10-100 ohms-cm. Zinc vapor annealing quenches the visible photoluminescence.

1974-01-01

313

Newcastle disease virus-induced cytopathic effect in infected cells is caused by apoptosis.  

PubMed

The velogenic Newcastle disease virus (NDV) causes highly infectious and economically significant Newcastle disease (ND) in birds of various species. In cell culture NDV induces cytopathic effect (CPE) characterized by rounding, vacuolation, syncytia formation and cell death. Aside from cell to cell fusion caused by the F and HN glycoprotein of the virus molecular events leading to cell death are not known. In the current study, NDV-infected Vero cells, at 48 h p.i., showed nuclear condensation, cytoplasm blebbing, DNA fragmentation, and phosphatidylserine translocation to the cell surface. In addition, virus-infected cells demonstrated decreased DNA content and an increased Bax to Bcl-2 ratio, p53 level and caspase 3, 8, 9 expression compared to mock-infected cells. Based on these results, it was concluded that CPE in NDV-infected cells was caused by to the induction of apoptosis with the involvement of p53 and the Bax, dependent apoptotic pathways. PMID:19152817

Ravindra, P V; Tiwari, Ashok K; Ratta, Barkha; Chaturvedi, Uttara; Palia, Sudesh Kumar; Chauhan, R S

2009-04-01

314

Effect of Photon Fluence Rate on Oxygen Evolution and Uptake by Chlamydomonas reinhardtii Suspensions Grown in Ambient and CO2-Enriched Air 1  

PubMed Central

A closed system consisting of an assimilation chamber furnished with a membrane inlet from the liquid phase connected to a mass spectrometer was used to measure O2 evolution and uptake by Chlamydomonas reinhardtii cells grown in ambient (0.034% CO2) or CO2-enriched (5% CO2) air. At pH = 6.9, 28°C and concentrations of dissolved inorganic carbon (DIC) saturating for photosynthesis, O2 uptake in the light (Uo) equaled O2 production (Eo) at the light compensation point (15 micromoles photons per square meter per second). Eo and Uo increased with increasing photon fluence rate (PFR) but were not rate saturated at 600 micromoles photons per square meter per second, while net O2 exchange reached a saturation level near 500 micromoles photons per square meter per second which was nearly the same for both, CO2-grown and air-grown cells. Comparison of the Uo/Eo ratios between air-grown and CO2-grown C. reinhardtii showed higher values for air-grown cells at light intensities higher than light compensation. For both, air-grown and CO2-grown algae the rates of mitochondrial O2 uptake in the dark measured immediately before and 5 minutes after illumination were much lower than Uo at PFR saturating for net photosynthesis. We conclude that noncyclic electron flow from water to NADP+ and pseudocyclic electron flow via photosystem I to O2 both significantly contribute to O2 exchange in the light. In contrast, mitochondrial respiration and photosynthetic carbon oxidation cycle are regarded as minor O2 consuming reactions in the light in both, air-grown and CO2-grown cells. It is suggested that the “extra” O2 uptake by air-grown algae provides ATP required for the energy dependent CO2/HCO3? concentrating mechanism known to be present in these cells. PMID:16664823

Sueltemeyer, Dieter F.; Klug, Klaus; Fock, Heinrich P.

1986-01-01

315

Effect of Photon Fluence Rate on Oxygen Evolution and Uptake by Chlamydomonas reinhardtii Suspensions Grown in Ambient and CO(2)-Enriched Air.  

PubMed

A closed system consisting of an assimilation chamber furnished with a membrane inlet from the liquid phase connected to a mass spectrometer was used to measure O(2) evolution and uptake by Chlamydomonas reinhardtii cells grown in ambient (0.034% CO(2)) or CO(2)-enriched (5% CO(2)) air. At pH = 6.9, 28 degrees C and concentrations of dissolved inorganic carbon (DIC) saturating for photosynthesis, O(2) uptake in the light (U(o)) equaled O(2) production (E(o)) at the light compensation point (15 micromoles photons per square meter per second). E(o) and U(o) increased with increasing photon fluence rate (PFR) but were not rate saturated at 600 micromoles photons per square meter per second, while net O(2) exchange reached a saturation level near 500 micromoles photons per square meter per second which was nearly the same for both, CO(2)-grown and air-grown cells. Comparison of the U(o)/E(o) ratios between air-grown and CO(2)-grown C. reinhardtii showed higher values for air-grown cells at light intensities higher than light compensation. For both, air-grown and CO(2)-grown algae the rates of mitochondrial O(2) uptake in the dark measured immediately before and 5 minutes after illumination were much lower than U(o) at PFR saturating for net photosynthesis. We conclude that noncyclic electron flow from water to NADP(+) and pseudocyclic electron flow via photosystem I to O(2) both significantly contribute to O(2) exchange in the light. In contrast, mitochondrial respiration and photosynthetic carbon oxidation cycle are regarded as minor O(2) consuming reactions in the light in both, air-grown and CO(2)-grown cells. It is suggested that the "extra" O(2) uptake by air-grown algae provides ATP required for the energy dependent CO(2)/HCO(3) (-) concentrating mechanism known to be present in these cells. PMID:16664823

Sueltemeyer, D F; Klug, K; Fock, H P

1986-06-01

316

Cytochemical localization of catalase activity in methanol-grown Hansenula polymorpha  

Microsoft Academic Search

The localization of peroxidase activity in methanol-grown cells of the yeast Hansenula polymorpha has been studied by a method based on cytochemical staining with diaminobenzidine (DAB). The oxidation product of DAB occurred in microbodies, which characteristically develop during growth on methanol, and in the intracristate space of the mitochondria.

J. P. van Dijken; M. Veenhuis; C. A. Vermeulen; W. Harder

1975-01-01

317

Nutrient management of soil grown crops  

Microsoft Academic Search

The management of the fertilization of soil grown crops in greenhouses can be distinguished in the addition of fertilizers before cultivation, the base dressing and those added during the cultivations period of the crops, the top dressing. The growing period of the crops in greenhouse production varies strongly. Some vegetable crops like radish and lettuce have a growing period between

C. Sonneveld; W. Voogt

2007-01-01

318

Transport studies on CVD-grown graphene  

E-print Network

In this thesis, we report transport studies performed on CVD-grown graphene. We perform resistivity and hall measurements on a large-area sample at 4' K. We measure the carrier mobility of the sample and find it to be on ...

Huntley, Miriam Hanna

2009-01-01

319

Efflux Of Nitrate From Hydroponically Grown Wheat  

NASA Technical Reports Server (NTRS)

Report describes experiments to measure influx, and efflux of nitrate from hydroponically grown wheat seedlings. Ratio between efflux and influx greater in darkness than in light; increased with concentration of nitrate in nutrient solution. On basis of experiments, authors suggest nutrient solution optimized at lowest possible concentration of nitrate.

Huffaker, R. C.; Aslam, M.; Ward, M. R.

1992-01-01

320

Grown-ups Ought To Know Better.  

ERIC Educational Resources Information Center

Among the articles by Sam Brightman collected in this volume from the newsletter, "Adult & Continuing Education Today (ACET)" are the following: "Grown-Ups Ought to Know Better"; "Adult Education: The Only Sure Factor Is Growth"; "Adult Education Important in This Election Year"; "Will Nursery School External Degree Programs Come Next?";…

Brightman, Samuel C.

321

Activation of the Nipah Virus Fusion Protein in MDCK Cells Is Mediated by Cathepsin B within the Endosome-Recycling Compartment  

PubMed Central

Proteolytic activation of the fusion protein of the highly pathogenic Nipah virus (NiV F) is a prerequisite for the production of infectious particles and for virus spread via cell-to-cell fusion. Unlike other paramyxoviral fusion proteins, functional NiV F activation requires endocytosis and pH-dependent cleavage at a monobasic cleavage site by endosomal proteases. Using prototype Vero cells, cathepsin L was previously identified to be a cleavage enzyme. Compared to Vero cells, MDCK cells showed substantially higher F cleavage rates in both NiV-infected and NiV F-transfected cells. Surprisingly, this could not be explained either by an increased F endocytosis rate or by elevated cathepsin L activities. On the contrary, MDCK cells did not display any detectable cathepsin L activity. Though we could confirm cathepsin L to be responsible for F activation in Vero cells, inhibitor studies revealed that in MDCK cells, cathepsin B was required for F-protein cleavage and productive replication of pathogenic NiV. Supporting the idea of an efficient F cleavage in early and recycling endosomes of MDCK cells, endocytosed F proteins and cathepsin B colocalized markedly with the endosomal marker proteins early endosomal antigen 1 (EEA-1), Rab4, and Rab11, while NiV F trafficking through late endosomal compartments was not needed for F activation. In summary, this study shows for the first time that endosomal cathepsin B can play a functional role in the activation of highly pathogenic NiV. PMID:22278224

Diederich, Sandra; Sauerhering, Lucie; Weis, Michael; Altmeppen, Hermann; Schaschke, Norbert; Reinheckel, Thomas; Erbar, Stephanie

2012-01-01

322

Sulfated proteoglycan synthesis by confluent cultures of rabbit costal chondrocytes grown in the presence of fibroblast growth factor  

PubMed Central

We examined the effect of fibroblast growth factor (FGF) on proteoglycan synthesis by rabbit costal chondrocyte cultures maintained on plastic tissue culture dishes. Low density rabbit costal chondrocyte cultures grown in the absence of FGF gave rise at confluency to a heterogeneous cell population composed of fibroblastic cells and poorly differentiated chondrocytes. When similar cultures were grown in the presence of FGF, the confluent cultures organized into a homogenous cartilage-like tissue composed of rounded cells surrounded by a refractile matrix. The cell ultrastructure and that of the pericellular matrix were similar to those seen in vivo. The expression of the cartilage phenotype in confluent chondrocyte cultures grown from the sparse stage in the presence vs. absence of FGF was reflected by a fivefold increase in the rate of incorporation of [35S]sulfate into proteoglycans. These FGF effects were only observed when FGF was present during the cell logarithmic growth phase, but not when it was added after chondrocyte cultures became confluent. High molecular weight, chondroitin sulfate proteoglycans synthesized by confluent chondrocyte cultures grown in the presence of FGF were slightly larger in size than that produced by confluent cultures grown in the absence of FGF. The major sulfated glycosaminoglycans associated with low molecular weight proteoglycan in FGF-exposed cultures were chondroitin sulfate, while in cultures not exposed to FGF they were chondroitin sulfate and dermatan sulfate. Regardless of whether or not cells were grown in the presence or absence of FGF, the 6S/4S disaccharide ratio of chondroitin sulfate chains associated with high and low molecular weight proteoglycans synthesized by confluent cultures was the same. These results provide evidence that when low density chondrocyte cultures maintained on plastic tissue culture dishes are grown in the presence of FGF, it results in a stimulation of the expression and stabilization of the chondrocyte phenotype once cultures become confluent. PMID:3968172

1985-01-01

323

Cells  

NSDL National Science Digital Library

Today you have the opportunity to explore the cell in a 3D fashion and learn more about its organelles. The following three links will help you understand the structure of the cell and organelles more clearly and help you understand their functions as well. Enjoy! Cells Alive Inside a Cell Virtual Cell When you have completed viewing the websites, please draw a picture of a animal cell or plant cell with its labeled parts. ...

Aird, Mrs.

2006-11-15

324

Characterization of Cellulolytic Bacterial Cultures Grown in Different Substrates  

PubMed Central

Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF) of palm kernel cake (PKC). The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30°C and agitated at 200?rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w) on different PKC concentration-to-moisture ratios: 1?:?0.2, 1?:?0.3, 1?:?0.4, and 1?:?0.5. Results showed that Bacillus amyloliquefaciens 1067?DSMZ, Bacillus megaterium 9885?ATCC, Paenibacillus curdlanolyticus 10248?DSMZ, and Paenibacillus polymyxa 842?ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC-to-moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC. PMID:24319380

Alshelmani, Mohamed Idris; Loh, Teck Chwen; Foo, Hooi Ling; Sazili, Awis Qurni

2013-01-01

325

Cytotoxicity of municipal solid waste incinerator ash wastes toward mammalian kidney cell lines.  

PubMed

In this study, three municipal solid waste incinerator (MSWI) ash wastes-bottom ash, scrubber residue, and baghouse ash-were extracted using a toxicity characteristic leaching procedure (TCLP) extractant. These so-called final TCLP extracts were applied to African green monkey kidney cells (Vero), baby hamster kidney cells (BHK-21), and pig kidney cells (PK-15), multi-well absorption reader analysis was performed to test how the cytotoxicity of the incineration ashes would affect the digestive systems of animals. Ion-coupled plasma analyses indicated that the baghouse ash extract possessed the highest pH and heavy metal concentration, its cytotoxicity was also the highest. In contrast, the bottom ash and the scrubber residue exhibited very low cytotoxicities. The cytotoxicities of mixtures of baghouse ash and scrubber residue toward the three tested cell lines increased as the relative ratio of the baghouse ash increased, especially for the Vero cells. The slight cytotoxicity of the scrubber residue arose mainly from the presence of Cr species, whereas the high cytotoxicity of the baghouse ash resulted from its high content of heavy metals and alkali ions. In addition, it appears that the dissolved total organic carbon content of these ash wastes can reduce the cytotoxicity of ash wastes that collect in animal cells. PMID:18329068

Huang, Wu-Jang; Tsai, Jia-Lin; Liao, Ming-Huei

2008-05-01

326

Lethal photosensitization of biofilm-grown bacteria  

NASA Astrophysics Data System (ADS)

Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

Wilson, Michael

1997-12-01

327

Counting molecular-beam grown graphene layers  

SciTech Connect

We have used the ratio of the integrated intensity of graphene's Raman G peak to that of the silicon substrate's first-order optical phonon peak, accurately to determine the number of graphene layers across our molecular-beam (MB) grown graphene films. We find that these results agree well both, with those from our own exfoliated single and few-layer graphene flakes, and with the results of Koh et al.[ACS Nano 5, 269 (2011)]. We hence distinguish regions of single-, bi-, tri-, four-layer, etc., graphene, consecutively, as we scan coarsely across our MB-grown graphene. This is the first, but crucial, step to being able to grow, by such molecular-beam-techniques, a specified number of large-area graphene layers, to order.

Plaut, Annette S. [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)] [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Wurstbauer, Ulrich [Department of Physics, Columbia University, New York, New York 10027 (United States)] [Department of Physics, Columbia University, New York, New York 10027 (United States); Pinczuk, Aron [Department of Physics, Columbia University, New York, New York 10027 (United States) [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Garcia, Jorge M. [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain)] [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain); Pfeiffer, Loren N. [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)] [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)

2013-06-17

328

Are randomly grown graphs really random?  

NASA Astrophysics Data System (ADS)

We analyze a minimal model of a growing network. At each time step, a new vertex is added; then, with probability ?, two vertices are chosen uniformly at random and joined by an undirected edge. This process is repeated for t time steps. In the limit of large t, the resulting graph displays surprisingly rich characteristics. In particular, a giant component emerges in an infinite-order phase transition at ?=1/8. At the transition, the average component size jumps discontinuously but remains finite. In contrast, a static random graph with the same degree distribution exhibits a second-order phase transition at ?=1/4, and the average component size diverges there. These dramatic differences between grown and static random graphs stem from a positive correlation between the degrees of connected vertices in the grown graph-older vertices tend to have higher degree, and to link with other high-degree vertices, merely by virtue of their age. We conclude that grown graphs, however randomly they are constructed, are fundamentally different from their static random graph counterparts.

Callaway, Duncan S.; Hopcroft, John E.; Kleinberg, Jon M.; Newman, M. E. J.; Strogatz, Steven H.

2001-10-01

329

Three distinct quinoprotein alcohol dehydrogenases are expressed when Pseudomonas putida is grown on different alcohols.  

PubMed Central

A bacterial strain that can utilize several kinds of alcohols as its sole carbon and energy sources was isolated from soil and tentatively identified as Pseudomonas putida HK5. Three distinct dye-linked alcohol dehydrogenases (ADHs), each of which contained the prosthetic group pyrroloquinoline quinone (PQQ), were formed in the soluble fractions of this strain grown on different alcohols. ADH I was formed most abundantly in the cells grown on ethanol and was similar to the quinoprotein ADH reported for P. putida (H. Görisch and M. Rupp, Antonie Leeuwenhoek 56:35-45, 1989) except for its isoelectric point. The other two ADHs, ADH IIB and ADH IIG, were formed separately in the cells grown on 1-butanol and 1,2-propanediol, respectively. Both of these enzymes contained heme c in addition to PQQ and functioned as quinohemoprotein dehydrogenases. Potassium ferricyanide was an available electron acceptor for ADHs IIB and IIG but not for ADH I. The molecular weights were estimated to be 69,000 for ADH IIB and 72,000 for ADH IIG, and both enzymes were shown to be monomers. Antibodies raised against each of the purified ADHs could distinguish the ADHs from one another. Immunoblot analysis showed that ADH I was detected in cells grown on each alcohol tested, but ethanol was the most effective inducer. ADH IIB was formed in the cells grown on alcohols of medium chain length and also on 1,3-butanediol. Induction of ADH IIG was restricted to 1,2-propanediol or glycerol, of which the former alcohol was more effective. These results from immunoblot analysis correlated well with the substrate specificities of the respective enzymes. Thus, three distinct quinoprotein ADHs were shown to be synthesized by a single bacterium under different growth conditions. PMID:7730276

Toyama, H; Fujii, A; Matsushita, K; Shinagawa, E; Ameyama, M; Adachi, O

1995-01-01

330

Interactions Between American Pondweed and Monoecious Hydrilla Grown in Mixtures  

Microsoft Academic Search

To assess the potential for monoecious hydrilla ( Hydrilla verticillata (L.f.) Royle) to invade existing aquatic plant com- munities, monoecious hydrilla was grown in mixtures with American pondweed ( Potamogeton nodosus Poiret). When grown with hydrilla from axillary turions, American pond- weed was a stronger competitor. When grown with hydrilla from tubers, American pondweed was equally as strong a competitor

DAVID F. SPENCER; GREGORY G. KSANDER

331

29 CFR 780.814 - “Grown in commercial quantities.”  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false âGrown in commercial quantities.â 780.814 Section 780...15) County Where Cotton Is Grown in Commercial Quantities § 780.814 “Grown in commercial quantities.” Cotton must be...

2012-07-01

332

29 CFR 780.814 - “Grown in commercial quantities.”  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false âGrown in commercial quantities.â 780.814 Section 780...15) County Where Cotton Is Grown in Commercial Quantities § 780.814 “Grown in commercial quantities.” Cotton must be...

2011-07-01

333

29 CFR 780.814 - “Grown in commercial quantities.”  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false âGrown in commercial quantities.â 780.814 Section 780...15) County Where Cotton Is Grown in Commercial Quantities § 780.814 “Grown in commercial quantities.” Cotton must be...

2013-07-01

334

29 CFR 780.814 - “Grown in commercial quantities.”  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false âGrown in commercial quantities.â 780.814 Section 780...15) County Where Cotton Is Grown in Commercial Quantities § 780.814 “Grown in commercial quantities.” Cotton must be...

2010-07-01

335

Cell lines that support replication of a novel herpes simplex virus 1 U{sub L}31 deletion mutant can properly target U{sub L}34 protein to the nuclear rim in the absence of U{sub L}31  

SciTech Connect

Previous results indicated that the herpes simplex virus 1 (HSV-1) U{sub L}31 gene is necessary and sufficient for localization of the U{sub L}34 protein exclusively to the nuclear membrane of infected Hep2 cells. In the current studies, a bacterial artificial chromosome containing the entire HSV-1 strain F genome was used to construct a recombinant viral genome in which a gene encoding kanamycin resistance was inserted in place of 262 codons of the 306 codon U{sub L}31 open reading frame. The deletion virus produced virus titers approximately 10- to 50-fold lower in rabbit skin cells, more than 2000-fold lower in Vero cells, and more than 1500-fold lower in CV1 cells, compared to a virus bearing a restored U{sub L}31 gene. The replication of the U{sub L}31 deletion virus was restored on U{sub L}31-complementing cell lines derived either from rabbit skin cells or CV1 cells. Confocal microscopy indicated that the majority of U{sub L}34 protein localized aberrantly in the cytoplasm and nucleoplasm of Vero cells and CV1 cells, whereas U{sub L}34 protein localized at the nuclear membrane in rabbit skin cells, and U{sub L}31 complementing CV1 cells infected with the U{sub L}31 deletion virus. We conclude that rabbit skin cells encode a function that allows proper localization of U{sub L}34 protein to the nuclear membrane. We speculate that this function partially complements that of U{sub L}31 and may explain why U{sub L}31 is less critical for replication in rabbit skin cells as opposed to Vero and CV1 cells.

Liang Li [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (United States); Tanaka, Michiko [Department of Virology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Kawaguchi, Yasushi [Department of Virology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Baines, Joel D. [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (United States)]. E-mail: jdb11@cornell.edu

2004-11-10

336

Auxin Transport Is Required for Hypocotyl Elongation in Light-Grown but Not Dark-Grown Arabidopsis1  

E-print Network

in darkness, however, NPA disrupted the gravity response but did not affect elongation. The extent of inhi 75% inhibition at 50 mol m 2 s 1 of white light. Plants grown under continuous blue or far-red light showed NPA-induced hypocotyl inhibition similar to that of white-light-grown plants. Plants grown under

Estelle, Mark

337

The antioxidant butylated hydroxyanisole potentiates the toxic effects of propylparaben in cultured mammalian cells.  

PubMed

Butylated hydroxyanisole and propylparaben are phenolic preservatives commonly used in food, pharmaceutical and personal care products. Both chemicals have been subjected to extensive toxicological studies, due to the growing concern regarding their possible impacts on environmental and human health. However, the cytotoxicity and underlying mechanisms of co-exposure to these compounds have not been explored. In this study, a set of relevant cytotoxicity endpoints including cell viability and proliferation, oxidative stress, DNA damage and gene expression changes were analyzed to assess whether the antioxidant butylated hydroxyanisole could prevent the pro-oxidant effects caused by propylparaben in Vero cells. We demonstrated that binary mixtures of both chemicals induce greater cytotoxic effects than those reported after single exposureto each compound. Simultaneous treatment with butylated hydroxyanisole and propylparaben caused G0/G1 cell cycle arrest as a result of enhanced generation of oxidative stress and DNA double strand breaks. DNA microarray analysis revealed that a cross-talk between transforming growth factor beta (TGF?) and ataxia-telangiectasia mutated kinase (ATM) pathways regulates the response of Vero cells to the tested compounds in binary mixture. Our findings indicate that butylated hydroxyanisole potentiates the pro-oxidant effects of propylparaben in cultured mammalian cells and provide useful information for their safety assessment. PMID:25086368

Martín, José Manuel Pérez; Freire, Paloma Fernández; Daimiel, Lidia; Martínez-Botas, Javier; Sánchez, Covadonga Martín; Lasunción, Miguel Ángel; Peropadre, Ana; Hazen, María José

2014-10-01

338

Characterization of the Initial Reactions during the Cometabolic Oxidation of Methyl tertButyl Ether by Propane-Grown Mycobacterium vaccae JOB5  

Microsoft Academic Search

The initial reactions in the cometabolic oxidation of the gasoline oxygenate, methyl tert-butyl ether (MTBE), by Mycobacterium vaccae JOB5 have been characterized. Two products, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), rapidly accumulated extracellularly when propane-grown cells were incubated with MTBE. Lower rates of TBF and TBA production from MTBE were also observed with cells grown on 1- or 2-propanol,

Christy A. Smith; Kirk T. O'Reilly; Michael R. Hyman

2003-01-01

339

Gene expression by the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough grown on an iron electrode under cathodic protection conditions.  

PubMed

The genome sequence of the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough was reanalyzed to design unique 70-mer oligonucleotide probes against 2,824 probable protein-coding regions. These included three genes not previously annotated, including one that encodes a c-type cytochrome. Using microarrays printed with these 70-mer probes, we analyzed the gene expression profile of wild-type D. vulgaris grown on cathodic hydrogen, generated at an iron electrode surface with an imposed negative potential of -1.1 V (cathodic protection conditions). The gene expression profile of cells grown on cathodic hydrogen was compared to that of cells grown with gaseous hydrogen bubbling through the culture. Relative to the latter, the electrode-grown cells overexpressed two hydrogenases, the hyn-1 genes for [NiFe] hydrogenase 1 and the hyd genes, encoding [Fe] hydrogenase. The hmc genes for the high-molecular-weight cytochrome complex, which allows electron flow from the hydrogenases across the cytoplasmic membrane, were also overexpressed. In contrast, cells grown on gaseous hydrogen overexpressed the hys genes for [NiFeSe] hydrogenase. Cells growing on the electrode also overexpressed genes encoding proteins which promote biofilm formation. Although the gene expression profiles for these two modes of growth were distinct, they were more closely related to each other than to that for cells grown in a lactate- and sulfate-containing medium. Electrochemically measured corrosion rates were lower for iron electrodes covered with hyn-1, hyd, and hmc mutant biofilms than for wild-type biofilms. This confirms the importance, suggested by the gene expression studies, of the corresponding gene products in D. vulgaris-mediated iron corrosion. PMID:18310429

Caffrey, Sean M; Park, Hyung Soo; Been, Jenny; Gordon, Paul; Sensen, Christoph W; Voordouw, Gerrit

2008-04-01

340

GaAs nanoneedles grown on sapphire  

NASA Astrophysics Data System (ADS)

Heterogeneous integration of dissimilar single crystals is of intense research interests. Lattice mismatch has been the most challenging bottleneck which limits the growth of sufficient active volume for functional devices. Here, we report self-assembled, catalyst-free, single crystalline GaAs nanoneedles grown on sapphire substrates with 46% lattice mismatch. The GaAs nanoneedles have a 2-3 nm tip, single wurtzite phase, excellent optical quality, and dimensions scalable with growth time. The needles have the same sharp, hexagonal pyramid shape from ˜100 nm (1.5 min growth) to ˜9 ?m length (3 h growth).

Chuang, Linus C.; Moewe, Michael; Ng, Kar Wei; Tran, Thai-Truong D.; Crankshaw, Shanna; Chen, Roger; Ko, Wai Son; Chang-Hasnain, Connie

2011-03-01

341

Reactive gold thin films grown on iridium  

NASA Astrophysics Data System (ADS)

We report results of our studies on the dissociative adsorption of hydrogen on Au thin films grown epitaxially on Ir{1 1 1} surface, using nuclear reaction analysis. We found that H 2 dissociatively adsorbs on these Au{1 1 1} films. This feature can be contrasted to the well-known noble bulk Au surfaces, which do not dissociate hydrogen molecules. We attribute this to the local surface properties, e.g., electron localization (the narrowing of the s-band, the s-band center model), which can explain the unexpected high reactivity of a thin Au{1 1 1} film.

Okada, Michio; Ogura, Shouhei; Diño, Wilson Agerico; Wilde, Markus; Fukutani, Katsuyuki; Kasai, Toshio

2005-06-01

342

Treatment of dark-grown Arabidopsis thaliana with a brassinosteroid-biosynthesis inhibitor, brassinazole, induces some characteristics of light-grown plants.  

PubMed

When a brassinosteroid biosynthesis inhibitor, brassinazole (Brz), was applied at concentrations ranging from 0.1 to 2 microM. Arabidopsis thaliana (L.) Heynh seedlings grown in the dark exhibited morphological features of light-grown plants, i.e. short hypocotyls, expanded cotyledons, and true leaves, in a dose-dependent manner. Control (non Brz-treated) seedlings grown in the dark for 40 d did not develop leaf primordia. However, treatment with the lowest concentration of Brz induced the development of leaf buds, although it hardly induced any short hypocotyls, and treatment with the highest concentration of Brz induced both short hypocotyls and leaves. Labeling experiments with the thymidine analogue 5-bromo-2'-deoxyuridine revealed that amplification of cell nuclei and organellar nucleoids is activated in the shoot apical meristems of dark-grown Brz-treated seedlings. These results suggest that Brz-treatment induces development of true leaves. Furthermore, condensation and scattering of plastid nucleoids, which is known to occur during the differentiation of etioplasts into chloroplasts, was observed in the plastids of dark-grown Brz-treated cotyledons. In addition, high levels of ribulose-1,5-bisphosphate carboxylase-oxygenase proteins accumulated in the plastids of the cotyledons. Electron microscopy showed that the plastids were etioplasts with a prolamellar body and few thylakoid membranes. These results suggest that Brz treatment in the dark induces the initial steps of plastid differentiation, which occur prior to the development of thylakoid membranes. This is a novel presumed function of brassinosteroids. These cytological changes seen in Brz-treated Arabidopsis were exactly the same as those seen in a brassinosteroid-biosynthesis-deficient mutant, det2, supporting the hypothesis that Brz has no side-effects except inhibiting brassinosteroid biosynthesis, and should prove a useful tool in clarifying the role of brassinosteroids. PMID:11144262

Nagata, N; Min, Y K; Nakano, T; Asami, T; Yoshida, S

2000-11-01

343

Solar Cells  

NASA Technical Reports Server (NTRS)

The Heat Exchanger Method (HEM) produces high efficiency crystal ingots in an automated well-insulated furnace offering low equipment, labor and energy costs. The "grown" silicon crystals are used to make solar cells, or photovoltaic cells which convert sunlight directly into electricity. The HEM method is used by Crystal Systems, Inc. and was developed under a NASA/Jet Propulsion Laboratory contract. The square wafers which are the result of the process are sold to companies manufacturing solar panels.

1983-01-01

344

Enhancement of Immune Activation Activities of Spirulina maxima Grown in Deep-Sea Water  

PubMed Central

In this study, the immuno-modulatory and anticancer activities of marine algae, Spirulina maxima grown in deep-sea water (DSW), were investigated. It was found that the extract of S. maxima, cultured in DSW, effectively suppressed the expression of Bcl2 in A549 cells as well as inhibiting various human cancer cells with concentration dependency, which possibly implies that the extracts may play more important roles in controlling cancer cell growth. The secretion of cytokines IL-6 and TNF-? from human B cells was also greatly increased, compared to those of the extract grown in conventional sea-water. The growth of Human Natural Killer (NK) cells in the presence of the extracts from DSW was significantly higher (12.2 × 104 viable cells/mL) when compared to the control (1.1 × 104 viable cells/mL). Based on HPLC analysis, the increase in the biological activities of the extracts from DSW was caused by considerably high amounts of ?-carotene and ascorbic acid because the DSW contained high concentrations and good ratios of several key minerals for biosynthesizing ?-carotene and ascorbic acid, as well as maintaining high cell growth. PMID:23743830

Choi, Woon Yong; Kang, Do Hyung; Lee, Hyeon Yong

2013-01-01

345

Defect study in molecular beam epitaxy-grown HgCdTe films with activated and unactivated arsenic  

NASA Astrophysics Data System (ADS)

A defect study was performed on molecular beam epitaxy-grown HgCdTe films in situ doped with arsenic. Doping was performed from either effusion cell or cracker cell, and studied were both as-grown samples and samples subjected to arsenic activation annealing. Electrical properties of the films were investigated with the use of ion milling as a means of "stirring" defects in the material. As a result of the study, it was confirmed that the most efficient incorporation of electrically active arsenic occurs at the cracking zone temperature of 700 °C. Interaction between arsenic and tellurium during the growth was observed and is discussed in the paper.

Izhnin, I. I.; Dvoretsky, S. A.; Mynbaev, K. D.; Fitsych, O. I.; Mikhailov, N. N.; Varavin, V. S.; Pociask-Bialy, M.; Voitsekhovskii, A. V.; Sheregii, E.

2014-04-01

346

Effect of Ottoman Viper (Montivipera xanthina (Gray, 1849)) Venom on Various Cancer Cells and on Microorganisms.  

PubMed

Cytotoxic and antimicrobial effects of Montivipera xanthina venom against LNCaP, MCF-7, HT-29, Saos-2, Hep3B, Vero cells and antimicrobial activity against selected bacterial and fungal species: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, E. coli O157H7, Enterococcus faecalis 29212, Enterococcus faecium DSM 13590, Staphylococcus epidermidis ATCC 12228, S. typhimirium CCM 5445, Proteus vulgaris ATCC 6957 and Candida albicans ATCC 10239 were studied for evaluating the potential medical benefit of this snake venom. Cytotoxicity of venom was determined using MTT assay. Snake venom cytotoxicity was expressed as the venom dose that killed 50 % of the cells (IC50). The antimicrobial activity of venom was studied by minimal inhibitory concentration (MIC) and disc diffusion assay. MIC was determined using broth dilution method. The estimated IC50 values of venom varied from 3.8 to 12.7 or from 1.9 to 7.2 ?g/ml after treatment with crude venom for 24 or 48 h for LNCaP, MCF-7, HT-29 and Saos-2 cells. There was no observable cytotoxic effect on Hep3B and Vero cells. Venom exhibited the most potent activity against C. albicans (MIC, 7.8 ?g/ml and minimal fungicidal concentration, 62.5 ?g/ml) and S. aureus (MIC, 31.25 ?g/ml). This study is the first report showing the potential of M. xanthina venom as an alternative therapeutic approach due to its cytotoxic and antimicrobial effects. PMID:23381026

Yalc?n, Husniye Tansel; Ozen, Mehmet Ozgün; Gocmen, Bayram; Nalbantsoy, Ayse

2014-01-01

347

Cratoxylum formosum (Jack) Dyer ssp. pruniflorum (Kurz) Gogel. (Hóng yá mù) extract induces apoptosis in human hepatocellular carcinoma HepG2 cells through caspase-dependent pathways  

PubMed Central

Background Cratoxylum formosum (Jack) Dyer ssp. pruniflorum (Kurz) Gogel. (Hóng yá mù) (CF) has been used for treatment of fever, cough, and peptic ulcer. Previously, a 50% ethanol-water extract from twigs of CF was shown highly selective in cytotoxicity against cancer cells. This study aims to investigate the molecular mechanisms underlying the apoptosis-inducing effect of CF. Methods The cytotoxicity of CF was evaluated in the human hepatocellular carcinoma (HCC) HepG2 cell line in comparison with a non-cancerous African green monkey kidney epithelial cell line (Vero) by a neutral red assay. The apoptosis induction mechanisms were investigated through nuclear morphological changes, DNA fragmentation, mitochondrial membrane potential alterations, and caspase enzyme activities. Results CF selectively induced HepG2 cell death compared with non-cancerous Vero cells. A 1.5-fold higher apoptotic effect compared with melphalan was induced by 120 ?g/mL of the 50% ethanol-water extract of CF. The apoptotic cell death in HepG2 cells occurred via extrinsic and intrinsic caspase-dependent pathways in dose- and time-dependent manners by significantly increasing the activities of caspase 3/7, 8, and 9, decreasing the mitochondrial membrane potential, and causing apoptotic body formation and DNA fragmentation. Conclusions CF extract induced a caspase-dependent apoptosis in HepG2 cells. PMID:24708784

2014-01-01

348

Cells  

NSDL National Science Digital Library

In this unit, students look at the components of cells and their functions and discover the controversy behind stem cell research. The first lesson focuses on the difference between prokaryotic and eukaryotic cells. In the second lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. The third lesson continues students' education on cells in the human body and how (and why) engineers are involved in the research of stem cell behavior.

Integrated Teaching And Learning Program

349

Quantitative Schlieren analysis applied to holograms of crystals grown on Spacelab 3  

NASA Technical Reports Server (NTRS)

In order to extract additional information about crystals grown in the microgravity environment of Spacelab, a quantitative schlieren analysis technique was developed for use in a Holography Ground System of the Fluid Experiment System. Utilizing the Unidex position controller, it was possible to measure deviation angles produced by refractive index gradients of 0.5 milliradians. Additionally, refractive index gradient maps for any recorded time during the crystal growth were drawn and used to create solute concentration maps for the environment around the crystal. The technique was applied to flight holograms of Cell 204 of the Fluid Experiment System that were recorded during the Spacelab 3 mission on STS 51B. A triglycine sulfate crystal was grown under isothermal conditions in the cell and the data gathered with the quantitative schlieren analysis technique is consistent with a diffusion limited growth process.

Brooks, Howard L.

1986-01-01

350

Quantitative Schlieren analysis applied to holograms of crystals grown on Spacelab 3  

NASA Astrophysics Data System (ADS)

In order to extract additional information about crystals grown in the microgravity environment of Spacelab, a quantitative schlieren analysis technique was developed for use in a Holography Ground System of the Fluid Experiment System. Utilizing the Unidex position controller, it was possible to measure deviation angles produced by refractive index gradients of 0.5 milliradians. Additionally, refractive index gradient maps for any recorded time during the crystal growth were drawn and used to create solute concentration maps for the environment around the crystal. The technique was applied to flight holograms of Cell 204 of the Fluid Experiment System that were recorded during the Spacelab 3 mission on STS 51B. A triglycine sulfate crystal was grown under isothermal conditions in the cell and the data gathered with the quantitative schlieren analysis technique is consistent with a diffusion limited growth process.

Brooks, Howard L.

1986-11-01

351

Cytotoxic activity of some lichen extracts on murine and human cancer cell lines.  

PubMed

Eight lichens were extracted successively with n-hexane, diethyl ether and methanol using a Soxhlet process. The cytotoxic activity of the 24 lichen extracts was evaluated in vitro using two murine (the L1210: lymphocytic leukaemia, and the 3LL: Lewis lung carcinoma) and four human (the K-562: chronic myelogenous leukaemia, the U251: glioblastoma, the DU145: prostate carcinoma, and the MCF7: breast adenocarcinoma) cancer cell lines and non-cancerous cells, the Vero cell line (African green monkey kidney cell line). The MTT assay revealed significant cytotoxicity (IC50 < or = 20 microg/ml) on one of the tested cancer cell lines for at least one extract of each lichen species. Some extracts of Cladonia convoluta, Cladonia rangiformis, Parmelia caperata, Platismatia glauca and Ramalina cuspidata demonstrated interesting activities particularly on human cancer cell lines as good selectivity indices were recorded (SI > 3). PMID:13678234

Bézivin, C; Tomasi, S; Lohézic-Le Dévéhat, F; Boustie, J

2003-01-01

352

Influence of stress on astaxanthin production in Haematococcus pluvialis grown under different culture conditions  

Microsoft Academic Search

The influence of stress was studied on astaxanthin production in Haematococcus pluvialis grown under different culture conditions. High concentrations of NaCl (>1.0% w\\/v) were lethal and the age of the culture was crucial for stress induced astaxanthin production. Four to-eight-day-old cultures were sensitive to NaCl addition while older cultures (12–16 days) were resistant. Older cells accumulated 8.3–10.69 mg\\/l astaxanthin compared

R Sarada; Usha Tripathi; G. A Ravishankar

2002-01-01

353

Leea indica Ethyl Acetate Fraction Induces Growth-Inhibitory Effect in Various Cancer Cell Lines and Apoptosis in Ca Ski Human Cervical Epidermoid Carcinoma Cells  

PubMed Central

The anticancer potential of Leea indica, a Chinese medicinal plant was investigated for the first time. The crude ethanol extract and fractions (ethyl acetate, hexane, and water) of Leea indica were evaluated their cytotoxicity on various cell lines (Ca Ski, MCF 7, MDA-MB-435, KB, HEP G2, WRL 68, and Vero) by MTT assay. Leea indica ethyl acetate fraction (LIEAF) was found showing the greatest cytotoxic effect against Ca Ski cervical cancer cells. Typical apoptotic morphological changes such as DNA fragmentation and chromatin condensation were observed in LIEAF-treated cells. Early signs of apoptosis such as externalization of phosphatidylserine and disruption of mitochondrial membrane potential indicated apoptosis induction. This was further substantiated by dose- and time-dependent accumulation of sub-G1 cells, depletion of intracellular glutathione, and activation of caspase-3. In conclusion, these results suggested that LIEAF inhibited cervical cancer cells growth by inducing apoptosis and could be developed as potential anticancer drugs. PMID:21423690

Yau Hsiung, Wong; Abdul Kadir, Habsah

2011-01-01

354

Peculiar properties of chlorophyll thermoluminescence emission of autotrophically or mixotrophically grown Chlamydomonas reinhardtii.  

PubMed

The microalgae Chlamydomonas reinhardtii and Chlorella sp. CCAP 211/84 were grown autotrophically and mixotrophically and their thermoluminescence emissions were recorded above 0 °C after excitation by 1, 2 or 3 xenon flashes or by continuous far-red light. An oscillation of the B band intensity according to the number of flashes was always observed, with a maximum after 2 flashes, accompanied by a downshift of the B band temperature maximum in mixotrophic compared to autotrophic grown cells, indicative of a dark stable pH gradient. Moreover, new flash-induced bands emerged in mixotrophic Chlamydomonas grown cells, at temperatures higher than that of the B band. In contrast to the afterglow band observed in higher plants, in Chlamydomonas these bands were not inducible by far-red light, were fully suppressed by 2 ?M antimycin A, and peaked at different temperatures depending on the flash number and growth stage, with higher temperature maxima in cells at a stationary compared to an exponential growth stage. These differences are discussed according to the particular properties of cyclic electron transfer pathways in C. reinhardtii. PMID:21402481

Ducruet, Jean-Marc; Serrano, Aurelio; Roncel, Mercedes; Ortega, José M

2011-01-01

355

Perfect crystals grown from imperfect interfaces  

PubMed Central

The fabrication of advanced devices increasingly requires materials with different properties to be combined in the form of monolithic heterostructures. In practice this means growing epitaxial semiconductor layers on substrates often greatly differing in lattice parameters and thermal expansion coefficients. With increasing layer thickness the relaxation of misfit and thermal strains may cause dislocations, substrate bowing and even layer cracking. Minimizing these drawbacks is therefore essential for heterostructures based on thick layers to be of any use for device fabrication. Here we prove by scanning X-ray nanodiffraction that mismatched Ge crystals epitaxially grown on deeply patterned Si substrates evolve into perfect structures away from the heavily dislocated interface. We show that relaxing thermal and misfit strains result just in lattice bending and tiny crystal tilts. We may thus expect a new concept in which continuous layers are replaced by quasi-continuous crystal arrays to lead to dramatically improved physical properties. PMID:23880632

Falub, Claudiu V.; Meduna, Mojmir; Chrastina, Daniel; Isa, Fabio; Marzegalli, Anna; Kreiliger, Thomas; Taboada, Alfonso G.; Isella, Giovanni; Miglio, Leo; Dommann, Alex; von Kanel, Hans

2013-01-01

356

Chloroplasts of Salt-Grown Arabidopsis Seedlings Are Impaired in Structure, Genome Copy Number and Transcript Levels  

PubMed Central

The chloroplast is the most prominent and metabolically active plastid in photosynthetic plants. Chloroplasts differentiate from proplastids in the plant meristem. Plant plastids contain multiple copies of a small circular genome. The numbers of chloroplasts per mesophyll cell and of plastid genome copies are affected by developmental stage and environmental signals. We compared chloroplast structure, gene expression and genome copy number in Arabidopsis seedlings germinated and grown under optimal conditions to those in seedlings germinated and grown in the presence of NaCl. Chloroplasts of the NaCl-grown seedlings were impaired, with less developed thylakoid and granum membranes than control seedlings. In addition, chloroplasts of salt-grown Arabidopsis seedlings accumulated more starch grains than those in the respective control plants. Steady-state transcript levels of chloroplast-encoded genes and of nuclear genes encoding chloroplast proteins were reduced in salt-grown seedlings. This reduction did not result from a global decrease in gene expression, since the expression of other nuclear genes was induced or not affected. Average cellular chloroplast genome copy number was reduced in salt-grown seedlings, suggesting that the reduction in steady-state transcript levels of chloroplast-encoded genes might result from a decrease in template DNA. PMID:24340039

Adler, Guy; Bar-Zvi, Dudy

2013-01-01

357

SARS Coronavirus Spike Protein Expression in HL-CZ Human Promonocytic Cells: Monoclonal Antibody and Cellular Transcriptomic Analyses  

Microsoft Academic Search

\\u000a The SARS coronavirus (CoV) spike protein is a target of intensive research, as it is a major virulence factor. Transfection\\u000a of SARS-CoV spike into Vero E6, HEK293T and HL-CZ cells leads to strong expression of the glycosylated spike protein, as shown\\u000a by Western blot analyses and immunofluorescent imaging using spike-specific human monoclonal antibodies, indicating the potential\\u000a utility of these antigens

T. Narasaraju; P. L. Soong; J. Meulen; J. Goudsmit; Vincent T. K. Chow

358

A low-temperature-grown TiO2-based device for the flexible stacked RRAM application  

NASA Astrophysics Data System (ADS)

Flexible TiO2 crossbar memory device arrays were fabricated on plastic substrates using amorphous titanium oxide thin films grown by the low-temperature plasma-enhanced atomic layer deposition method. Al/ TiO2 /Al memory cells on polyethersulfone (PES) showed an enhanced endurance property (up to 104 cycles) and low switching voltages compared to the cells on rigid substrates. The multi-stacked memory arrays were constructed by forming the additional Al/ TiO2 /Al layer on the first memory device layer. Memory cells on each layer exhibited stable switching characteristics and mechanical robustness without interlayer cell-to-cell interference.

Jeong, Hu Young; In Kim, Yong; Lee, Jeong Yong; Choi, Sung-Yool

2010-03-01

359

Plasma-Mediated Inactivation of Pseudomonas aeruginosa Biofilms Grown on Borosilicate Surfaces under Continuous Culture System.  

PubMed

Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturabilty are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the inactivation/sterilization of biofilms grown in a continuous system. PMID:25302815

Vandervoort, Kurt G; Brelles-Mariño, Graciela

2014-01-01

360

Plasma-Mediated Inactivation of Pseudomonas aeruginosa Biofilms Grown on Borosilicate Surfaces under Continuous Culture System  

PubMed Central

Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturabilty are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the inactivation/sterilization of biofilms grown in a continuous system. PMID:25302815

Vandervoort, Kurt G.; Brelles-Marino, Graciela

2014-01-01

361

Journal of Crystal Growth 241 (2002) 4550 Boron doping of silicon layers grown by liquid phase epitaxy  

E-print Network

Journal of Crystal Growth 241 (2002) 45�50 Boron doping of silicon layers grown by liquid phase film solar cell applications as it allows the growth of a back surface field and a lightly doped bulk in a single growth step. r 2002 Elsevier Science B.V. All rights reserved. Keywords: A3. Liquid phase epitaxy

362

Quantitative genetic analysis of morphological variation in an antarctic diatom grown at two light intensities. [Thalassiosira tumida  

Microsoft Academic Search

Ten clonal isolates of Thalassiosira tumida (Janisch) Hasle were grown in duplicate semi-continuous batch cultures at 116 and 11.6 E x m S x s ; acclimated cells were harvested during exponential growth and cleaned for examination by light microscopy (LM) and scanning electron microscopy (SEM). Number of strutted processes surrounding the central annulus (SP) and average number of satellite

A. M. Wood; R. Lande; G. A. Fryxell

1987-01-01

363

Roughness and texture of epitaxial LZO thin films grown on RABiTS Ni5W substrates  

E-print Network

steps of the synthesis process of the coated conductor [9, 10]. This buffer layer is used as a template mismatch with Ni5W and is grown by epitaxy on Ni5W after a rotation of 45° of its unit cell for better matching the substrate lattice [14]. Due to this property, many papers showed that LZO reproduced exactly

Paris-Sud XI, Université de

364

Breakdown Current Density of CVD-Grown Multilayer Graphene Interconnects  

Microsoft Academic Search

Graphene wires have been fabricated from large-area multilayer graphene sheets grown by chemical vapor deposition. As the methane concentration increases, a larger percentage of thicker graphene layers are grown. The multilayer graphene sheets have an average thickness of 10-20 nm with sheet resistances between 500 and 1000 ?\\/sq. The sheet resistance shows a strong correlation with the average surface roughness.

Kyeong-Jae Lee; Anantha P. Chandrakasan; Jing Kong

2011-01-01

365

Phosphorus Management of Lucerne Grown on Calcareous Soil in Turkey  

Microsoft Academic Search

Lucerne or alfalfa (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires phosphorus (P) additions as the soils are naturally P deficient. Phosphorus sorption isotherms were used to estimate P fertilizer needs for lucerne grown for two years in a 3-cut system on a calcareous P deficient

Metin Turan; F. Mehmet Kiziloglu; Quirine M. Ketterings

2009-01-01

366

29 CFR 780.813 - “County where cotton is grown.”  

...2014-07-01 false âCounty where cotton is grown.â 780.813 Section 780...STANDARDS ACT Employment in Ginning of Cotton and Processing of Sugar Beets, Sugar-Beet...Section 13(b)(15) County Where Cotton Is Grown in Commercial Quantities...

2014-07-01

367

GaN Nanowires Grown by Molecular Beam Epitaxy  

Microsoft Academic Search

The unique properties of GaN nanowires grown by molecular beam epitaxy are reviewed. These properties include the absence of residual strain, exclusion of most extended defects, long photoluminescence lifetime, low surface recombination ve- locity, and high mechanical quality factor. The high purity of the nanowires grown by this method allows for controllable n- type doping. P-type doping presents more challenges

Kris A. Bertness; Norman A. Sanford; Albert V. Davydov

2011-01-01

368

Electrical characterization of electrochemically grown single copper nanowires  

E-print Network

Electrical characterization of electrochemically grown single copper nanowires M. E. Toimil 2003 Single- and poly-crystalline copper wires with diameters down to 30 nm are grown in etched ion functioning as semi- conductor elements or simply as connectors to or within molecular devices are very

Ludwig-Maximilians-Universität, München

369

Vapor grown silicon dioxide improves transistor base-collector junctions  

NASA Technical Reports Server (NTRS)

Vapor grown silicon dioxide layer protects base-collector junction in silicon planar transistors during the emitter diffusion process. This oxide fills in any imperfections that exist in the thermally grown oxide layer and is of greater thickness than that layer. This process is used to deposit protective silicon dioxide coatings on optical surfaces.

Carley, D. R.; Duclos, R. A.

1966-01-01

370

Phyllosphere Microbiota Composition and Microbial Community Transplantation on Lettuce Plants Grown Indoors  

PubMed Central

ABSTRACT The aerial surfaces of plants, or phyllosphere, are microbial habitats important to plant and human health. In order to accurately investigate microbial interactions in the phyllosphere under laboratory conditions, the composition of the phyllosphere microbiota should be representative of the diversity of microorganisms residing on plants in nature. We found that Romaine lettuce grown in the laboratory contained 10- to 100-fold lower numbers of bacteria than age-matched, field-grown lettuce. The bacterial diversity on laboratory-grown plants was also significantly lower and contained relatively higher proportions of Betaproteobacteria as opposed to the Gammaproteobacteria-enriched communities on field lettuce. Incubation of field-grown Romaine lettuce plants in environmental growth chambers for 2 weeks resulted in bacterial cell densities and taxa similar to those on plants in the field but with less diverse bacterial populations overall. In comparison, the inoculation of laboratory-grown Romaine lettuce plants with either freshly collected or cryopreserved microorganisms recovered from field lettuce resulted in the development of a field-like microbiota on the lettuce within 2 days of application. The survival of an inoculated strain of Escherichia coli O157:H7 was unchanged by microbial community transfer; however, the inoculation of E. coli O157:H7 onto those plants resulted in significant shifts in the abundance of certain taxa. This finding was strictly dependent on the presence of a field-associated as opposed to a laboratory-associated microbiota on the plants. Phyllosphere microbiota transplantation in the laboratory will be useful for elucidating microbial interactions on plants that are important to agriculture and microbial food safety. PMID:25118240

Williams, Thomas R.

2014-01-01

371

Arsenic Modulates Cell Proliferation Pathways in MCF-7 Breast Cancer Cells Krystle Brown, Somaly Neang, Dorrelyn Patacsil, and Deepak Kumar  

E-print Network

. OBJECTIVES MATERIALS AND METHODS Cell Culture and Reagents: MCF-7 cells were grown as monolayer in Dulbecco's modified Eagle medium (DMEM) (Invitrogen) supplemented with 5% heat-inactivated fetal bovine serum and 25 g/ml gentamicin. The cells were grown and maintained in 75-cm2 tissue culture flasks in a humidified atmosphere

District of Columbia, University of the

372

Comparison of virulence properties of Pseudomonas aeruginosa exposed to water and grown in rich broth.  

PubMed

Pseudomonas aeruginosa is an opportunistic pathogen that can infect susceptible patients suffering from cystic fibrosis, immunosuppression, and severe burns. Nosocomial- and community-acquired infection is likely due to contact with water sources contaminated with P. aeruginosa. Most of what is known about the virulence properties of P. aeruginosa was derived from studies using fairly rich broths, which do not represent conditions found in water, such as low nutrient concentrations. Here, we compare biofilm production, invasion of epithelial cells, cytotoxicity, and pyocyanin production of P. aeruginosa in water with P. aeruginosa grown in rich broth. Since tap water is variable, we used a defined water medium, Fraquil, to ensure reproducibility of the results. We found that P. aeruginosa does not readily form biofilm in Fraquil. Pseudomonas aeruginosa is equally able to attach to and invade epithelial cells but is more cytotoxic after incubation in water for 30 days than when it is grown in rich broth. Moreover, P. aeruginosa produces less pyocyanin when exposed to water. Our results show that P. aeruginosa seems to have different properties when exposed to water than when grown in rich broth. PMID:25352257

Mendis, Nilmini; Lin, Ying Ran; Faucher, Sebastien P

2014-11-01

373

Secretomic survey of Trichoderma harzianum grown on plant biomass substrates.  

PubMed

The present work aims at characterizing T. harzianum secretome when the fungus is grown in synthetic medium supplemented with one of the four substrates: glucose, cellulose, xylan, and sugarcane bagasse (SB). The characterization was done by enzymatic assays and proteomic analysis using 2-DE/MALDI-TOF and gel-free shotgun LC-MS/MS. The results showed that SB induced the highest cellulolytic and xylanolytic activities when compared with the other substrates, while remarkable differences in terms of number and distribution of protein spots in 2-DE gels were also observed among the samples. Additionally, treatment of the secretomes with PNGase F revealed that most spot trails in 2-DE gels corresponded to N-glycosylated proteoforms. The LC-MS/MS analysis of the samples identified 626 different protein groups, including carbohydrate-active enzymes and accessory, noncatalytic, and cell-wall-associated proteins. Although the SB-induced secretome displayed the highest cellulolytic and xylanolytic activities, it did not correspond to a higher proteome complexity because CM-cellulose-induced secretome was significantly more diverse. Among the identified proteins, 73% were exclusive to one condition, while only 5% were present in all samples. Therefore, this study disclosed the variation of T. harzianum secretome in response to different substrates and revealed the diversity of the fungus enzymatic toolbox. PMID:24593137

Gómez-Mendoza, Diana Paola; Junqueira, Magno; do Vale, Luis Henrique Ferreira; Domont, Gilberto Barbosa; Ferreira Filho, Edivaldo Ximenes; Sousa, Marcelo Valle de; Ricart, Carlos André Ornelas

2014-04-01

374

Cometabolic degradation of chlorinated alkenes by alkene monooxygenase in a propylene-grown Xanthobacter strain.  

PubMed Central

Propylene-grown Xanthobacter cells (strain Py2) degraded several chlorinated alkenes of environmental concern, including trichloroethylene, 1-chloroethylene (vinyl chloride), cis- and trans-1,2-dichloroethylene, 1,3-dichloropropylene, and 2,3-dichloropropylene. 1,1-Dichloroethylene was not degraded efficiently, while tetrachloroethylene was not degraded. The role of alkene monooxygenase in catalyzing chlorinated alkene degradations was established by demonstrating that glucose-grown cells which lack alkene monooxygenase and propylene-grown cells in which alkene monooxygenase was selectively inactivated by propyne were unable to degrade the compounds. C2 and C3 chlorinated alkanes were not oxidized by alkene monooxygenase, but a number of these compounds were inhibitors of propylene and ethylene oxidation, suggesting that they compete for binding to the enzyme. A number of metabolites enhanced the rate of degradation of chlorinated alkenes, including propylene oxide, propionaldehyde, and glucose. Propylene stimulated chlorinated alkene oxidation slightly when present at a low concentration but became inhibitory at higher concentrations. Toxic effects associated with chlorinated alkene oxidations were determined by measuring the propylene oxidation and propylene oxide-dependent O2 uptake rates of cells previously incubated with chlorinated alkenes. Compounds which were substrates for alkene monooxygenase exhibited various levels of toxicity, with 1,1-dichloroethylene and trichloroethylene being the most potent inactivators of propylene oxidation and 1,3- and 2,3-dichloropropylene being the most potent inactivators of propylene oxide-dependent O2 uptake. No toxic effects were seen when cells were incubated with chlorinated alkenes anaerobically, indicating that the product(s) of chlorinated alkene oxidation mediates toxicity. PMID:1444418

Ensign, S A; Hyman, M R; Arp, D J

1992-01-01

375

A Three-Dimensional Comparison of Tick-Borne Flavivirus Infection in Mammalian and Tick Cell Lines  

PubMed Central

Tick-borne flaviviruses (TBFV) are sustained in nature through cycling between mammalian and tick hosts. In this study, we used African green monkey kidney cells (Vero) and Ixodes scapularis tick cells (ISE6) to compare virus-induced changes in mammalian and arthropod cells. Using confocal microscopy, transmission electron microscopy (TEM), and electron tomography (ET), we examined viral protein distribution and the ultrastructural changes that occur during TBFV infection. Within host cells, flaviviruses cause complex rearrangement of cellular membranes for the purpose of virus replication. Virus infection was accompanied by a marked expansion in endoplasmic reticulum (ER) staining and markers for TBFV replication were localized mainly to the ER in both cell lines. TEM of Vero cells showed membrane-bound vesicles enclosed in a network of dilated, anastomosing ER cisternae. Virions were seen within the ER and were sometimes in paracrystalline arrays. Tubular structures or elongated vesicles were occasionally noted. In acutely and persistently infected ISE6 cells, membrane proliferation and vesicles were also noted; however, the extent of membrane expansion and the abundance of vesicles were lower and no viral particles were observed. Tubular profiles were far more prevalent in persistently infected ISE6 cells than in acutely infected cells. By ET, tubular profiles, in persistently infected tick cells, had a cross-sectional diameter of 60–100 nm, reached up to 800 nm in length, were closed at the ends, and were often arranged in fascicle-like bundles, shrouded with ER membrane. Our experiments provide analysis of viral protein localization within the context of both mammalian and arthropod cell lines as well as both acute and persistent arthropod cell infection. Additionally, we show for the first time 3D flavivirus infection in a vector cell line and the first ET of persistent flavivirus infection. PMID:23112871

Offerdahl, Danielle K.; Dorward, David W.; Hansen, Bryan T.; Bloom, Marshall E.

2012-01-01

376

VHL Induces Renal Cell Differentiation and Growth Arrest through Integration of Cell-Cell and Cell-Extracellular Matrix Signaling  

PubMed Central

Mutations in the von Hippel-Lindau (VHL) gene are involved in the family cancer syndrome for which it is named and the development of sporadic renal cell cancer (RCC). Reintroduction of VHL into RCC cells lacking functional VHL [VHL(?)] can suppress their growth in nude mice, but not under standard tissue culture conditions. To examine the hypothesis that the tumor suppressor function of VHL requires signaling through contact with extracellular matrix (ECM), 786-O VHL(?) RCC cells and isogenic sublines stably expressing VHL gene products [VHL(+)] were grown on ECMs. Cell-cell and cell-ECM signalings were required to elicit VHL-dependent differences in growth and differentiation. VHL(+) cells differentiated into organized epithelial sheets, whereas VHL(?) cells were branched and disorganized. VHL(+) cells grown to high density on collagen I underwent growth arrest, whereas VHL(?) cells continued to proliferate. Integrin levels were up-regulated in VHL(?) cells, and cell adhesion was down-regulated in VHL(+) cells during growth at high cell density. Hepatocyte nuclear factor 1?, a transcription factor and global activator of proximal tubule-specific genes in the nephron, was markedly up-regulated in VHL(+) cells grown at high cell density. These data indicate that VHL can induce renal cell differentiation and mediate growth arrest through integration of cell-cell and cell-ECM signals. PMID:11154273

Davidowitz, Eliot J.; Schoenfeld, Alan R.; Burk, Robert D.

2001-01-01

377

Schmallenberg virus challenge models in cattle: infectious serum or culture-grown virus?  

PubMed Central

Schmallenberg virus (SBV), discovered in Europe in 2011, causes mild transient disease in adult ruminants, but fetal infection can lead to severe malformation in cattle, sheep and goats. To elucidate the pathogenesis of this novel orthobunyavirus, considerable efforts are required. A reliable and standardized infection model is essential for in vivo studies. In the present study, two groups of four cattle were inoculated with either serum passaged in cattle only or cell culture-grown virus. The replication of culture-grown SBV in cattle was reduced compared to virus inoculated via infectious serum. In a second experiment, the infectious serum was titrated in calves; the tested batch contained 102.83 infectious doses per mL. Hence, serum-borne virus that was only passaged in the natural host is a suitable option for a standardized SBV infection model. PMID:23231006

2012-01-01

378

Electron transport in acetate-grown Methanosarcina acetivorans  

PubMed Central

Background Acetate is the major source of methane in nature. The majority of investigations have focused on acetotrophic methanogens for which energy-conserving electron transport is dependent on the production and consumption of H2 as an intermediate, although the great majority of acetotrophs are unable to metabolize H2. The presence of cytochrome c and a complex (Ma-Rnf) homologous to the Rnf (Rhodobacter nitrogen fixation) complexes distributed in the domain Bacteria distinguishes non-H2-utilizing Methanosarcina acetivorans from H2-utilizing species suggesting fundamentally different electron transport pathways. Thus, the membrane-bound electron transport chain of acetate-grown M. acetivorans was investigated to advance a more complete understanding of acetotrophic methanogens. Results A component of the CO dehydrogenase/acetyl-CoA synthase (CdhAE) was partially purified and shown to reduce a ferredoxin purified using an assay coupling reduction of the ferredoxin to oxidation of CdhAE. Mass spectrometry analysis of the ferredoxin identified the encoding gene among annotations for nine ferredoxins encoded in the genome. Reduction of purified membranes from acetate-grown cells with ferredoxin lead to reduction of membrane-associated multi-heme cytochrome c that was re-oxidized by the addition of either the heterodisulfide of coenzyme M and coenzyme B (CoM-S-S-CoB) or 2-hydoxyphenazine, the soluble analog of methanophenazine (MP). Reduced 2-hydoxyphenazine was re-oxidized by membranes that was dependent on addition of CoM-S-S-CoB. A genomic analysis of Methanosarcina thermophila, a non-H2-utilizing acetotrophic methanogen, identified genes homologous to cytochrome c and the Ma-Rnf complex of M. acetivorans. Conclusions The results support roles for ferredoxin, cytochrome c and MP in the energy-conserving electron transport pathway of non-H2-utilizing acetotrophic methanogens. This is the first report of involvement of a cytochrome c in acetotrophic methanogenesis. The results suggest that diverse acetotrophic Methanosarcina species have evolved diverse membrane-bound electron transport pathways leading from ferredoxin and culminating with MP donating electrons to the heterodisulfide reductase (HdrDE) for reduction of CoM-S-S-CoB. PMID:21781343

2011-01-01

379

Heart tissue grown in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

Lisa Freed and Gordana Vunjak-Novakovic, both of the Massachusetts Institute of Technology (MIT), have taken the first steps toward engineering heart muscle tissue that could one day be used to patch damaged human hearts. Cells isolated from very young animals are attached to a three-dimensional polymer scaffold, then placed in a NASA bioreactor. The cells do not divide, but after about a week start to cornect to form a functional piece of tissue. Functionally connected heart cells that are capable of transmitting electrical signals are the goal for Freed and Vunjak-Novakovic. Electrophysiological recordings of engineered tissue show spontaneous contractions at a rate of 70 beats per minute (a), and paced contractions at rates of 80, 150, and 200 beats per minute respectively (b, c, and d). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. 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. 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 MIT.

2001-01-01

380

Diamond films grown from fullerene precursors  

SciTech Connect

Fullerene precursors have been shown to result in the growth of diamond films from argon microwave plasmas. In contradistinction to most diamond films grown using conventional methane-hydrogen mixtures, the fullerene-generated films are nanocrystalline and smooth on the nanometer scale. They have recently been shown to have friction coefficients approaching the values of natural diamond. It is clearly important to understand the development of surface morphology during film growth from fullerene precursors and to elucidate the factors leading to surface roughness when hydrogen is present in the chemical vapor deposition (CVD) gas mixtures. To achieve these goals, we are measuring surface reflectivity of diamond films growing on silicon substrates over a wide range of plasma processing conditions. A model for the interpretation of the laser interferometric data has been developed, which allows one to determine film growth rate, rms surface roughness, and bulk losses due to scattering and absorption. The rms roughness values determined by reflectivity are in good agreement with atomic force microscope (AFM) measurements. A number of techniques, including high-resolution transmission electron microscopy (HRTEM) and near-edge x-ray absorption find structure (NEXAFS) measurements, have been used to characterize the films. A mechanism for diamond-film growth involving the C{sub 2} molecule as a growth species will be presented. The mechanism is based on (1) the observation that the optical emission spectra of the fullerene- containing plasmas are dominated by the Swan bands of C{sub 2} and (2) the ability of C{sub 2} to insert directly into C-H and C-C bonds with low activation barriers, as shown by recent theoretical calculations of reactions of C{sub 2} with carbon clusters.

Gruen, D.M.; Zuiker, C.D.; Krauss, A.R.

1995-07-01

381

Mutational dynamics of the SARS coronavirus in cell culture and human populations isolated in 2003  

PubMed Central

Background The SARS coronavirus is the etiologic agent for the epidemic of the Severe Acute Respiratory Syndrome. The recent emergence of this new pathogen, the careful tracing of its transmission patterns, and the ability to propagate in culture allows the exploration of the mutational dynamics of the SARS-CoV in human populations. Methods We sequenced complete SARS-CoV genomes taken from primary human tissues (SIN3408, SIN3725V, SIN3765V), cultured isolates (SIN848, SIN846, SIN842, SIN845, SIN847, SIN849, SIN850, SIN852, SIN3408L), and five consecutive Vero cell passages (SIN2774_P1, SIN2774_P2, SIN2774_P3, SIN2774_P4, SIN2774_P5) arising from SIN2774 isolate. These represented individual patient samples, serial in vitro passages in cell culture, and paired human and cell culture isolates. Employing a refined mutation filtering scheme and constant mutation rate model, the mutation rates were estimated and the possible date of emergence was calculated. Phylogenetic analysis was used to uncover molecular relationships between the isolates. Results Close examination of whole genome sequence of 54 SARS-CoV isolates identified before 14th October 2003, including 22 from patients in Singapore, revealed the mutations engendered during human-to-Vero and Vero-to-human transmission as well as in multiple Vero cell passages in order to refine our analysis of human-to-human transmission. Though co-infection by different quasipecies in individual tissue samples is observed, the in vitro mutation rate of the SARS-CoV in Vero cell passage is negligible. The in vivo mutation rate, however, is consistent with estimates of other RNA viruses at approximately 5.7 × 10-6 nucleotide substitutions per site per day (0.17 mutations per genome per day), or two mutations per human passage (adjusted R-square = 0.4014). Using the immediate Hotel M contact isolates as roots, we observed that the SARS epidemic has generated four major genetic groups that are geographically associated: two Singapore isolates, one Taiwan isolate, and one North China isolate which appears most closely related to the putative SARS-CoV isolated from a palm civet. Non-synonymous mutations are centered in non-essential ORFs especially in structural and antigenic genes such as the S and M proteins, but these mutations did not distinguish the geographical groupings. However, no non-synonymous mutations were found in the 3CLpro and the polymerase genes. Conclusions Our results show that the SARS-CoV is well adapted to growth in culture and did not appear to undergo specific selection in human populations. We further assessed that the putative origin of the SARS epidemic was in late October 2002 which is consistent with a recent estimate using cases from China. The greater sequence divergence in the structural and antigenic proteins and consistent deletions in the 3' – most portion of the viral genome suggest that certain selection pressures are interacting with the functional nature of these validated and putative ORFs. PMID:15347429

Vega, Vinsensius B; Ruan, Yijun; Liu, Jianjun; Lee, Wah Heng; Wei, Chia Lin; Se-Thoe, Su Yun; Tang, Kin Fai; Zhang, Tao; Kolatkar, Prasanna R; Ooi, Eng Eong; Ling, Ai Ee; Stanton, Lawrence W; Long, Philip M; Liu, Edison T

2004-01-01

382

Cell isolation and culture.  

PubMed

Cell isolation and culture are essential tools for the study of cell function. Isolated cells grown under controlled conditions can be manipulated and imaged at a level of resolution that is not possible in whole animals or even tissue explants. Recent advances have allowed for large-scale isolation and culture of primary C. elegans cells from both embryos and all four larval stages. Isolated cells can be used for single-cell profiling, electrophysiology, and high-resolution microscopy to assay cell autonomous development and behavior. This chapter describes protocols for the isolation and culture of C. elegans embryonic and larval stage cells. Our protocols describe isolation of embryonic and L1 stage cells from nematodes grown on high-density NA22 bacterial plates and isolation of L2 through L4 stage cells from nematodes grown in axenic liquid culture. Both embryonic and larval cells can be isolated from nematode populations within 3 hours and can be cultured for several days. A primer on sterile cell culture techniques is given in the appendices. PMID:23430760

Zhang, Sihui; Kuhn, Jeffrey R

2013-01-01

383

Heart tissue grown in NASA Bioreactor  

NASA Technical Reports Server (NTRS)

Lisa Freed and Gordana Vunjak-Novakovic, both of the Massachusetts Institute of Technology (MIT), have taken the first steps toward engineering heart muscle tissue that could one day be used to patch damaged human hearts. Cells isolated from very young animals are attached to a three-dimensional polymer scaffold, then placed in a NASA bioreactor. The cells do not divide, but after about a week start to cornect to form a functional piece of tissue. Here, a transmission electron micrograph of engineered tissue shows a number of important landmarks present in functional heart tissue: (A) well-organized myofilaments (Mfl), z-lines (Z), and abundant glycogen granules (Gly); and (D) intercalcated disc (ID) and desmosomes (DES). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. 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. 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: MIT

2001-01-01

384

The SCHIZOID gene regulates differentiation and cell division in Arabidopsis thaliana shoots  

Microsoft Academic Search

.  ?Cell division and cell differentiation are key processes in shoot development. The Arabidopsis thaliana (L.) Heynh. SCHIZOID (SHZ) gene appears to influence cell differentiation and cell division in the shoot. The shz-2 mutant is notable in that distinct phenotypes develop, depending on the environment in which the plants are grown. When shz-2 mutants are grown in petri dishes, callus develops

Ronald L. Parsons; Friedrich J. Behringer; June I. Medford

2000-01-01

385

7 CFR 989.157 - Raisins produced from grapes grown outside of California.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Raisins produced from grapes grown outside of California. 989...OF AGRICULTURE RAISINS PRODUCED FROM GRAPES GROWN IN CALIFORNIA Administrative Rules... § 989.157 Raisins produced from grapes grown outside of California....

2011-01-01

386

Auxin Transport Is Required for Hypocotyl Elongation in Light-Grown but Not Dark-Grown Arabidopsis1  

PubMed Central

Many auxin responses are dependent on redistribution and/or polar transport of indoleacetic acid. Polar transport of auxin can be inhibited through the application of phytotropins such as 1-naphthylphthalamic acid (NPA). When Arabidopsis thaliana seedlings were grown in the light on medium containing 1.0 ?m NPA, hypocotyl and root elongation and gravitropism were strongly inhibited. When grown in darkness, however, NPA disrupted the gravity response but did not affect elongation. The extent of inhibition of hypocotyl elongation by NPA increased in a fluence-rate-dependent manner to a maximum of about 75% inhibition at 50 ?mol m?2 s?1 of white light. Plants grown under continuous blue or far-red light showed NPA-induced hypocotyl inhibition similar to that of white-light-grown plants. Plants grown under continuous red light showed less NPA-induced inhibition. Analysis of photoreceptor mutants indicates the involvement of phytochrome and cryptochrome in mediating this NPA response. Hypocotyls of some auxin-resistant mutants had decreased sensitivity to NPA in the light, but etiolated seedlings of these mutants were similar in length to the wild type. These results indicate that light has a significant effect on NPA-induced inhibition in Arabidopsis, and suggest that auxin has a more important role in elongation responses in light-grown than in dark-grown seedlings. PMID:9489005

Jensen, Philip J.; Hangarter, Roger P.; Estelle, Mark

1998-01-01

387

Method for fabricating silicon cells  

DOEpatents

A process for making high-efficiency solar cells. This is accomplished by forming a diffusion junction and a passivating oxide layer in a single high-temperature process step. The invention includes the class of solar cells made using this process, including high-efficiency solar cells made using Czochralski-grown silicon.

Ruby, Douglas S. (Albuquerque, NM); Basore, Paul A. (Albuquerque, NM); Schubert, W. Kent (Albuquerque, NM)

1998-08-11

388

Method for fabricating silicon cells  

DOEpatents

A process is described for making high-efficiency solar cells. This is accomplished by forming a diffusion junction and a passivating oxide layer in a single high-temperature process step. The invention includes the class of solar cells made using this process, including high-efficiency solar cells made using Czochralski-grown silicon. 9 figs.

Ruby, D.S.; Basore, P.A.; Schubert, W.K.

1998-08-11

389

Environmental effects on flavour development in Australian - grown strawberry varieties.  

E-print Network

??The volatile compositions of two popular strawberry varieties, Albion (US-bred) and Juliette (Australian-bred), grown in Australia were analysed with comprehensive two-dimensional gas chromatography (GC×GC) combined… (more)

Samykanno, K

2012-01-01

390

ESFI-SOS transistors on as-grown sapphire wafers  

Microsoft Academic Search

The possibility to grow the silicon film on an as-grown substrate rather than on a mechanically processed substrate is considered. The concept is implemented with the aid of sapphire wafers obtained by the edge-defined film-fed growth (EFG) technique. The wafers are ground on one side only, the other side remaining as an as-grown substrate. The principal advantage of the use

H. Splittgerber; D. Takacs; H. Schloetterer

1977-01-01

391

Sizing Up the Cell  

NSDL National Science Digital Library

This perspective discusses new information and experimental methods used in the study of the kinetics of cell growth and its influence on cell division. The coordination of cell growth and division is responsible for fundamental characteristics of cells such as their size: Fast growth with slow division makes big cells, whereas slow growth with fast division makes small cells. Yet despite decades of effort, the kinetics of cell growth and its influence on cell division have remained elusive topics, at least for animal cells. Is cell growth linear (constant) or exponential (proportional to cell size)? Does cell division occur after cells have grown beyond a minimum size, or is there rather some âÂÂage of consentâ for division, or both? A report by Tzur et al. combines a new experimental method with careful mathematical analysis to answer these questions for cultured mammalian lymphoblasts.

Bruce Edgar (Fred Hutchinson Cancer Research Center;); Kerry Kim (University of Washington;Center for Cell Dynamics, Friday Harbor Labs)

2009-07-10

392

Survival of Potentially Pathogenic Human-Associated Bacteria in the Rhizosphere of Hydroponically Grown Wheat  

NASA Technical Reports Server (NTRS)

Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(exp 8 cu/ml)) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aeruginosa showed considerable growth. E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition.

Morales, Anabelle; Garland, Jay L.; Lim, Daniel V.

1996-01-01

393

Tailoring the optical characteristics of microsized InP nanoneedles directly grown on silicon.  

PubMed

Nanoscale self-assembly offers a pathway to realize heterogeneous integration of III-V materials on silicon. However, for III-V nanowires directly grown on silicon, dislocation-free single-crystal quality could only be attained below certain critical dimensions. We recently reported a new approach that overcomes this size constraint, demonstrating the growth of single-crystal InGaAs/GaAs and InP nanoneedles with the base diameters exceeding 1 ?m. Here, we report distinct optical characteristics of InP nanoneedles which are varied from mostly zincblende, zincblende/wurtzite-mixed, to pure wurtzite crystalline phase. We achieved, for the first time, pure single-crystal wurtzite-phase InP nanoneedles grown on silicon with bandgaps of 80 meV larger than that of zincblende-phase InP. Being able to attain excellent material quality while scaling up in size promises outstanding device performance of these nanoneedles. At room temperature, a high internal quantum efficiency of 25% and optically pumped lasing are demonstrated for single nanoneedle as-grown on silicon substrate. Recombination dynamics proves the excellent surface quality of the InP nanoneedles, which paves the way toward achieving multijunction photovoltaic cells, long-wavelength heterostructure lasers, and advanced photonic integrated circuits. PMID:24299042

Li, Kun; Sun, Hao; Ren, Fan; Ng, Kar Wei; Tran, Thai-Truong D; Chen, Roger; Chang-Hasnain, Connie J

2014-01-01

394

Steady state protein levels in Geobacter metallireducens grown with Iron (III) citrate or nitrate as terminal electron acceptor.  

SciTech Connect

Geobacter species predominate in aquatic sediments and submerged soils where organic carbon sources are oxidized with the reduction of Fe(III). The natural occurrence of Geobacter in some waste sites suggests this microorganism could be useful for bioremediation if growth and metabolic activity can be regulated. 2-DE was used to monitor the steady state protein levels of Geobacter metallireducens grown with either Fe(III) citrate or nitrate to elucidate metabolic differences in response to different terminal electron acceptors present in natural environments populated by Geobacter. Forty-six protein spots varied significantly in abundance (p<0.05) between the two growth conditions; proteins were identified by tryptic peptide mass and peptide sequence determined by MS/MS. Enzymes involved in pyruvate metabolism and the tricarboxylic acid (TCA) cycle were more abundant in cells grown with Fe(III) citrate, while proteins associated with nitrate metabolism and sensing cellular redox status along with several proteins of unknown function were more abundant in cells grown with nitrate. These results indicate a higher level of flux through the TCA cycle in the presence of Fe(III) compared to nitrate. The oxidative stress response observed in previous studies of Geobacter sulfurreducens grown with Fe(III) citrate was not seen in G. metallireducens.

Ahrendt, A. J.; Tollaksen, S. L.; Lindberg, C.; Zhu, W.; Yates, J. R., III; Nevin, K. P.; Lovley, D.; Giometti, C. S.; Biosciences Division; The Scripps Research Inst.; Univ. of Massachusetts

2007-01-01

395

Immortalized chick embryo cell line adapted to serum-free growth conditions and capable of replicating human and reassortant H5N1 influenza strains for vaccine production.  

PubMed

The current process of influenza vaccine production can take 6-9 months and is dependent on the availability of embryonated eggs. Additionally, this process selects for receptor-binding variants with reduced antigenicity and requires significant downstream production for purification. We have established an immortalized chick embryo cell line, termed PBS-12SF, which is adapted to growth in serum free conditions, and is capable of replicating human and reassortant H5N1 influenza strains to high titers. In many cases, PBS-12SF cells produced higher growth titers of influenza virus than those of primary chick embryo kidney (CEK) cells, Madin-Darby Canine Kidney (MDCK) cells and African green monkey kidney cells (Vero). Additionally, in PBS-12SF cell cultures, influenza virus is released into the culture fluid without need for exogenous proteases, which can simplify downstream processing for vaccine production. PMID:21911025

Coussens, Paul M; Smith, Kristen A; Weber, Patty S D; Colvin, Christopher J

2011-11-01

396

Linobiflavonoid inhibits human lung adenocarcinoma A549 cells: effect on tubulin protein.  

PubMed

The antitumor bioactivities of linobiflavonoid were studied through evaluating its in vitro cytotoxicity against several cell lines (A549, H1975, SMMC-7721, HEP-2 and Vero cells), with the aid of 3-(4,5)-dimethylthiazoly1)-3,5-diphenytetrazolium bromide (MTT) assay. It was found that linobiflavonoid shows more notable inhibiting activity against A549 cells, with IC50 value of 4.67 ?M. Furthermore, western blot analysis revealed that linobiflavonoid is able to increase the expression of ?-tubulin, whereas not ?-tubulin. In virtuale simulations indicated that linobiflavonoid specifically interacts with the binding pocket which is located at the top of ?-tubulin, due to the presence of strong hydrophobic effects between the core templates and the hydrophobic surface of the tubulin protein (TB) binding site. The binding energy (E inter ) was calculated to be -140.47 kcal/mol. Results above suggest that linobiflavonoid possesses anti-A549 properties relating to ?-tubulin depolymerization inhibition. PMID:24057268

Zhao, Dongbo; Yang, Guang; Meng, Qingyang; Liu, Junxing; Yang, Shuang

2013-10-01

397

Stability of the glycoprotein gene of avian metapneumovirus (Canada goose isolate 15a/01) after serial passages in cell cultures.  

PubMed

The glycoprotein (G) gene sequences of avian metapneumovirus (aMPV) subtypes A, B, C, and D are variable in size and number of nucleotides. The G gene of early U.S. turkey isolates of aMPV-C have been reported to be 1798 nucleotides (nt) (585 aa) in length, whereas the G genes of more recent turkey isolates have been reported to be 783 nucleotides. In some studies, the G gene of aMPV-C turkey isolates was found to be truncated to a smaller G gene of 783 nt (261 aa) upon serial passages in Vero cells. This is believed to be due to the deletion of 1015 nt near the end of the open reading frame. The purpose of this study was to determine variation, if any, in the G gene of an aMPV-C isolated from a wild bird (Canada goose [Branta canadensis]) following serial passages in Vero cells. No size variation was observed for up to 50 passages, except for a few amino acid changes in the extracellular domain at the 50th passage level. The G gene of this wild bird isolate appears to be unique from subtype C metapneumoviruses of turkeys. PMID:20608539

Chockalingam, Ashok K; Chander, Yogesh; Halvorson, David A; Goyal, Sagar M

2010-06-01

398

Glycolate metabolism in low and high CO sub 2 -grown chlorella pyrenoidosa and Pavlova lutheri as determined by sup 18 O-labeling  

SciTech Connect

Photorespiration in Chlorella pyrenoidosa Chick. was assayed by measuring {sup 18}O-labeled intermediates of the glycolate pathway. Glycolate, glycine, serine, and excreted glycolate were isolated and analyzed on a gas chromatograph/mass spectrometer to determine isotopic enrichment. Rates of glycolate synthesis were determined from {sup 18}O-labeling kinetics of the intermediates, pool sizes, derived rate equations, and nonlinear regression techniques. Glycolate synthesis was higher in high CO{sub 2}-grown cells than in air-grown cells when both were assayed under the same O{sub 2} and CO{s