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Sample records for thermotolerant chinese hamster

  1. Effects of proliferation on the decay of thermotolerance in Chinese hamster cells.

    Science.gov (United States)

    Armour, E P; Li, G C; Hahn, G M

    1985-09-01

    Development and decay of thermotolerance were observed in Chinese hamster HA-1 cells. The thermotolerance kinetics of exponentially growing and fed plateau-phase cells were compared. Following a 10-min heat exposure at 45 degrees C, cells in both growth states had similar rates of development of tolerance to a subsequent 45-min exposure at 45 degrees C. This thermotolerant state started to decay between 12 and 24 hr after the initial heat exposure. The decay appeared to initiate slightly sooner in the exponentially growing cells when compared to the fed plateau-phase cells. During the decay phase, the rate of thermotolerance decay was similar in the two growth conditions. In other experiments, cells were induced to divide at a slower rate by chronic growth (3 months) in a low concentration of fetal calf serum. Under these low serum conditions cells became more sensitive to heat and the rate of decay of thermotolerance remained the same for exponentially growing cells. Plateau-phase cells were also more sensitive, but thermotolerance decayed more rapidly in these cells. Although dramatic cell cycle perturbations were seen in the exponentially growing cells, these changes appeared not to be related to thermotolerance kinetics.

  2. Track segment studies with Chinese hamster cells

    International Nuclear Information System (INIS)

    Bird, R.P.

    1984-01-01

    Survival curves of near-diploid and near-tetraploid Chinese hamster cell cultures following irradiation by an 241 Am α source indicate different growth rates for the two clones. Possible reasons for the difference are discussed

  3. Proteomic Analysis of Chinese Hamster Ovary Cells

    DEFF Research Database (Denmark)

    Baycin-Hizal, Deniz; Tabb, David L.; Chaerkady, Raghothama

    2012-01-01

    To complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO cells including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multidimens......To complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO cells including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis...

  4. Methods for modeling chinese hamster ovary (cho) cell metabolism

    DEFF Research Database (Denmark)

    2015-01-01

    Embodiments of the present invention generally relate to the computational analysis and characterization biological networks at the cellular level in Chinese Hamster Ovary (CHO) cells. Based on computational methods utilizing a hamster reference genome, the invention provides methods...

  5. Dominant white spotting in the Chinese hamster.

    Science.gov (United States)

    Henwood, C; Henwood, J; Robinson, R

    1987-01-01

    An autosomal dominant white spotting mutant is described for the Chinese hamster. The mutant gene is designated as dominant spot (symbol Ds). The homozygote DsDs is a prenatal lethal while the heterozygote Ds + displays white spotting. The expression of white is variable, ranging from a white forehead spot to extensive white on the body. The venter is invariably white. Growth appears to be normal and the fertility of both sizes shows no impairment.

  6. Culture conditions affecting the survival response of Chinese hamster ovary cells treated by hyperthermia

    International Nuclear Information System (INIS)

    Highfield, D.P.; Holahan, E.V.; Dewey, W.C.

    1982-01-01

    Using lethally irradiated feeder cells to control cell population densities, researchers investigated the survival of Chinese hamster ovary cells heated between 42.2 and 45.5 degrees C. Test cells were plated into T25 flasks with or without feeder cells, incubated 2 hours at 37 degrees C, and then given various heat treatments. Under all heating conditions, survival increased in those flasks containing feeder cells. Increased survival (by as much as a factor of 100 for cells heated at 42.4 degrees C for 6-10 hr) was most apparent when cells were heated to thermotolerance. By adjustment of test and feeder cell numbers, survival increased as density increased; however, maximum survival followed a transition period that occurred between the plating of 1 X 10(4) and 6 X 10(4) cells. Experimental artifacts due to improper control of cell density was demonstrated

  7. Radioprotective effect of catecholamines on the cultured Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Chirkov, Yu.Yu.; Malatsidze, M.A.; Sobolev, A.S.

    1985-01-01

    On cultivated in vitro Chinese hamster fibroblasts radioprotective properties of adrenaline, noradrenaline and isoproterenol in different concentrations are studied. Isoproterenol radiopreventive effect is clearly manifested with its concentration being 1x10 -8 M; adrenaline and noradrenaline are efficient in higher concentrations. Propranolol, blocking β-adrenergic receptors, completely presents radioprotective effect of catecholamines on the cells. β-adrenergic mechanism of catecholamine radioprotective effect on Mammalia cells is discussed

  8. Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines

    International Nuclear Information System (INIS)

    Hata, H.; Numata, M.; Tohda, H.; Yasui, A.; Oikawa, A.

    1991-01-01

    1-[(4-Amino-2-methylpyrimidin-5-yl)methyl]-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar to that of the parental cell lines CHO9. One mutant (UVS1) was cross-sensitive to UV and complemented the UV sensitivity of all Chinese hamster cell lines of 7 established complementation groups. Since UV-induced unscheduled DNA synthesis was very low, a new locus related to excision repair is thought to be defective in this cell line. Another ACNU-sensitive mutant, CNU1, was slightly more sensitive to UV than the parent cell line. CNU1 was cross-sensitive to 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and slightly more sensitive to mitomycin C. No increased accumulation of ACNU and a low level of UV-induced unscheduled DNA synthesis in this cell as compared with the parental cell line suggest that there is abnormality in a repair response of this mutant cell to some types of DNA cross-links

  9. Enhancement of postreplication repair in Chinese hamster cells

    International Nuclear Information System (INIS)

    D'Ambrosio, S.M.; Setlow, R.B.

    1976-01-01

    Alkaline sedimentation profiles of pulse-labeled DNA from Chinese hamster cells showed that DNA from cells treated with N-acetoxy-acetylaminofluorene or ultraviolet radiation was made in segments smaller than those from untreated cells. Cells treated with a small dose (2.5 μM) of N-acetoxy-acetylaminofluorene or(2.5 J . m -2 ) 254-nm radiation, several hours before a larger dose (7 to 10 μM) of N-acetoxy-acetylaminofluorene or 5.0 J . m -2 of 254-nm radiation, also synthesized small DNA after the second dose. However, the rate at which this small DNA was joined together into parental size was appreciably greater than in absence of the small dose. This enhancement of postreplication repair (as a result of the initial small dose) was not observed when cells were incubated with cycloheximide between the two treatments. The results suggest that N-acetoxy-acetylaminofluorene and ultraviolet-damaged DNA from Chinese hamster cells are repaired by similar postreplicative mechanisms that require de novo protein synthesis for enhancement

  10. Chinese hamster genome database: an online resource for the CHO community at www.CHOgenome.org.

    Science.gov (United States)

    Hammond, Stephanie; Kaplarevic, Mihailo; Borth, Nicole; Betenbaugh, Michael J; Lee, Kelvin H

    2012-06-01

    The Chinese hamster genome database (http://www.chogenome.org/) is an online resource for the Chinese hamster (Cricetulus griseus) and Chinese hamster ovary (CHO) cell communities. CHO cells are important for biomedical research and are widely used in industry for the production of biopharmaceuticals. The genome of the CHO-K1 cell line was recently sequenced and the CHO community has developed an online resource to facilitate accessibility of the genomic data and the development of genomic tools. Copyright © 2011 Wiley Periodicals, Inc.

  11. Spermatogenesis is accelerated in the immature Djungarian and Chinese hamster and rat

    NARCIS (Netherlands)

    van Haaster, L. H.; de rooij, D. G.

    1993-01-01

    The rate of progression of spermatogenesis was studied in immature Djungarian and Chinese hamsters and Wistar rats by scoring the most advanced cell types present at various ages after birth. From 15 days of age onward, the most advanced cell types in the Djungarian hamsters were formed at a rate

  12. Mitotic spindle proteomics in Chinese hamster ovary cells.

    Directory of Open Access Journals (Sweden)

    Mary Kate Bonner

    Full Text Available Mitosis is a fundamental process in the development of all organisms. The mitotic spindle guides the cell through mitosis as it mediates the segregation of chromosomes, the orientation of the cleavage furrow, and the progression of cell division. Birth defects and tissue-specific cancers often result from abnormalities in mitotic events. Here, we report a proteomic study of the mitotic spindle from Chinese Hamster Ovary (CHO cells. Four different isolations of metaphase spindles were subjected to Multi-dimensional Protein Identification Technology (MudPIT analysis and tandem mass spectrometry. We identified 1155 proteins and used Gene Ontology (GO analysis to categorize proteins into cellular component groups. We then compared our data to the previously published CHO midbody proteome and identified proteins that are unique to the CHO spindle. Our data represent the first mitotic spindle proteome in CHO cells, which augments the list of mitotic spindle components from mammalian cells.

  13. Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant

    International Nuclear Information System (INIS)

    Mitchell, J.B.; Gamson, J.; Russo, A.; Friedman, N.; DeGraff, W.; Carmichael, J.; Glatstein, E.

    1988-01-01

    The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance

  14. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    DEFF Research Database (Denmark)

    Hefzi, Hooman; Ang, Kok Siong; Hanscho, Michael

    2016-01-01

    Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways...

  15. Genomic organization and expression of immunoglobulin genes in the Chinese hamster (Cricetulus griseus).

    Science.gov (United States)

    Qin, T; Zhu, H; Wang, D; Hao, H; Du, W

    2015-01-01

    In science, the hamsters are widely used as a model for studying the human diseases because they display many features like humans. The utility of the Chinese hamster as a biology model can be further enhanced by further characterization of the genes encoding components of the immune system. Here, we report the genomic organization and expression of the Chinese hamster immunoglobulin heavy and light chain genes. The Chinese hamster IgH locus contains 268 VH segments (132 potentially functional genes, 12 ORFs and 124 pseudogenes), 4 DH segments, 6 JH segments, four constant region genes (μ, γ, ε and α) and one reverse δ remnant fragment. The Igκ locus contains only a single Cκ gene, 4 Jκ segments and 48 Vκ segments (15 potentially functional genes and 33 pseudogenes), whereas the Igλ locus contains 4 Cλ genes, but only Cλ 3 and Cλ 4 each preceded by a Jλ gene segment. A total of 49 Vλ segments (39 potentially functional genes, 3 ORFs and 7 pseudogenes) were identified. Analysis of junctions of the recombined V(D)J transcripts reveals complex diversity in both expressed H and κ sequences, but the microhomology-directed VJ recombination obviously results in very limited diversity in the Chinese hamster λ gene despite more potential germline-encoded combinatorial diversity. This is the first study to make a comprehensive analysis of the Ig genes in the Chinese hamster, which provides insights into the Ig genes in placental mammals. © 2014 John Wiley & Sons Ltd.

  16. Systemic immune response to Acanthamoeba keratitis in the Chinese hamster.

    Science.gov (United States)

    Van Klink, F; Leher, H; Jager, M J; Alizadeh, H; Taylor, W; Niederkorn, J Y

    1997-12-01

    Recrudescence is a common and troubling feature of Acanthamoeba keratitis and suggests that corneal infection with this organism fails to stimulate the systemic immune apparatus. The present study examined the cell-mediated and humoral immune responses to Acanthamoeba keratitis in the Chinese hamster. Corneal infection with A. castellanii failed to induce either delayed-type hypersensitivity (DTH) or serum IgG antibody against parasite antigens. The failure to induce cell-mediated and humoral immunity did not result in anergy or tolerance since subsequent intramuscular (i.m.) immunization with parasite antigens elicited robust DTH and IgG antibody responses. The inability of corneal infections to induce primary cell-mediated immune responses was due to the absence of resident antigen-presenting cells in the central cornea because induction of Langerhans cell (LC) migration into the central cornea prior to infection with Acanthamoeba promoted the development of parasite-specific DTH. Although the presence of resident LC did not promote the development of a primary humoral immune response, subsequent i.m. immunization elicited heightened parasite-specific IgG antibody production which was indicative of an anamnestic response. Collectively, the results indicate that in the absence of resident antigen-presenting cells, corneal infection with Acanthamoeba fails to stimulate primary cell-mediated or humoral immunity. Induction of peripheral LC into the central corneal epithelium promotes the development of parasite-specific DTH, but does not exacerbate corneal disease.

  17. Vitamin K metabolism in Chinese Hamster Ovary cells

    International Nuclear Information System (INIS)

    Hoffman, H.S.

    1986-01-01

    Recent investigations suggest that vitamin K may have functions other than in blood coagulation and calcification. The present study was undertaken to investigate this hypothesis using cells in culture. Chinese Hamster Ovary (CHO) cells were chosen due to their active metabolism and growth and lack of similarity to liver and bone cells, in which vitamin K metabolism is well known. Cells were adapted to serum-free media, incubated in media containing the appropriate concentrations of vitamin K for specified times, scraped from plates, pelleted, extensively washed to remove adhering vitamin K, extracted with chloroform:methanol (2:1, v/v) and analyzed on C18 HPLC columns. Uptake of vitamin K by CHO cells follows saturation kinetics at vitamin K concentrations up to 25 μ M and is transported into cells at the rate of 10 pmol/min. 10 6 cells. After 24 hours, 3 H vitamin K is metabolized by CHO cells to several compounds, the major of which was isolated and identified as vitamin K epoxide. In 3 experiments, after 24 hours, the average cellular uptake of vitamin K was 8% with approximately half being metabolized to vitamin K epoxide. These results demonstrate that vitamin K is metabolized in cells with widely different functions and suggest a generalized function for vitamin K which has yet to be elucidated

  18. Response of the microtubular cytoskeleton following hyperthermia as a prognostic indicator of survival of Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Coss, Ronald A.; Alden, Mark E.; Wachsberger, Phyllis R.; Smith, Nancy N.

    1996-01-01

    Purpose: The response of the microtubular (MT) cytoskeleton to hyperthermia was assessed as a prognostic indicator of cytotoxicity. Methods and Materials: Heat-induced collapse and subsequent recovery of the MT system were compared with survival for both nonthermotolerant (NT) and thermotolerant (TT) G1 populations of Chinese hamster ovary (CHO) cells. The response of the MT system was monitored using immunofluorescence staining. The G1 populations of NT and TT cells were heated by submersion in 45.0 and 43.0 deg. C waterbaths. Results: Heat-induced perinuclear collapse of the MT system did not correlate with survival for the NT and TT populations. However, recovery of the organization of the MT cytoskeleton was correlatable with survival. The regression line of survival plotted as a function of MT recovery is fit by: y = -0.43 + 1.03x, r 2 = 0.95 (p < 0.0005). Conclusion: Restoration of the organization of the MT cytoskeleton following hyperthermia may be used as a prognostic indicator of survival of CHO cells heated in G1

  19. DIP and DIP + 2 as glutathione oxidants and radiation sensitizers in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Harris, J.W.; Power, J.A.; Kosower, N.S.; Kosower, E.M.

    1975-01-01

    Two diamide analogues, diazene dicarboxylic acid bis (N'-methyl-piperazide) or DIP, and its bis-N'-methyl iodide salt, or DIP + 2, were tested for their ability to penetrate cultured Chinese hamster cells and oxidize intracellular glutathione. DIP penetrated the cells at a reasonable rate at 18 0 C, 160 nmoles being required to oxidize the endogenous glutathione of 2 x 10 6 cells, but it penetrated very slowly at 0 0 C. DIP + 2 did not effectively oxidize glutathione in Chinese hamster cells, possibly because it did not enter the cels. DIP became toxic after about 10 min of exposure, but its toxicity could be moderated by using anoxic conditions. DIP, but not DIP + 2, sensitized anoxic Chinese hamster cells to X-radiation by a factor of 1.5, an effect that was due entirely to removal of the shoulder from the survival curve. (author)

  20. Multistep change in epidermal growth factor receptors during spontaneous neoplastic progression in Chinese hamster embryo fibroblasts

    International Nuclear Information System (INIS)

    Wakshull, E.; Kraemer, P.M.; Wharton, W.

    1985-01-01

    Whole Chinese hamster embryo lineages have been shown to undergo multistep spontaneous neoplastic progression during serial passage in culture. The authors have studied the binding, internalization, and degradation of 125 I-labeled epidermal growth factor at four different stages of transformation. The whole Chinese hamster embryo cells lost cell surface epidermal growth factor receptors gradually during the course of neoplastic progression until only 10% of the receptor number present in the early-passage cells (precrisis) were retained in the late-passage cells (tumorigenic). No differences in internalization rates, chloroquine sensitivity, or ability to degrade hormone between the various passage levels were seen. No evidence for the presence in conditioned medium of transforming growth factors which might mask or down-regulate epidermal growth factor receptor was obtained. These results suggest that a reduction in cell surface epidermal growth factor receptor might be an early event during spontaneous transformation in whole Chinese hamster embryo cells

  1. Model-based analysis of N-glycosylation in Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Krambeck, Frederick J.; Bennun, Sandra V; Andersen, Mikael Rørdam

    2017-01-01

    in glycan structure. In this study we utilize an updated version of this model to provide a comprehensive analysis of N-glycosylation in ten Chinese hamster ovary (CHO) cell lines that include a wild type parent and nine mutants of CHO, through interpretation of previously published mass spectrometry data......The Chinese hamster ovary (CHO) cell is the gold standard for manufacturing of glycosylated recombinant proteins for production of biotherapeutics. The similarity of its glycosylation patterns to the human versions enable the products of this cell line favorable pharmacokinetic properties and lower...

  2. Genomic landscapes of Chinese hamster ovary cell lines as revealed by the Cricetulus griseus draft genome

    DEFF Research Database (Denmark)

    Lewis, Nathan E; Liu, Xin; Li, Yuxiang

    2013-01-01

    Chinese hamster ovary (CHO) cells, first isolated in 1957, are the preferred production host for many therapeutic proteins. Although genetic heterogeneity among CHO cell lines has been well documented, a systematic, nucleotide-resolution characterization of their genotypic differences has been...... stymied by the lack of a unifying genomic resource for CHO cells. Here we report a 2.4-Gb draft genome sequence of a female Chinese hamster, Cricetulus griseus, harboring 24,044 genes. We also resequenced and analyzed the genomes of six CHO cell lines from the CHO-K1, DG44 and CHO-S lineages....... This analysis identified hamster genes missing in different CHO cell lines, and detected >3.7 million single-nucleotide polymorphisms (SNPs), 551,240 indels and 7,063 copy number variations. Many mutations are located in genes with functions relevant to bioprocessing, such as apoptosis. The details...

  3. Trends and approaches in N-Glycosylation engineering in Chinese hamster ovary cell culture

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    Chinese hamster ovary (CHO) cells have become the preferred expression system for the production of complex recombinantglycoproteins. It has been historically successful in industrial scale-up application and in generating human-like protein glycosylation.N-glycosylation of recombinant proteins...

  4. The genomic sequence of the Chinese hamster ovary (CHO)-K1 cell line

    DEFF Research Database (Denmark)

    Xu, Xun; Pan, Shengkai; Liu, Xin

    2011-01-01

    Chinese hamster ovary (CHO)-derived cell lines are the preferred host cells for the production of therapeutic proteins. Here we present a draft genomic sequence of the CHO-K1 ancestral cell line. The assembly comprises 2.45 Gb of genomic sequence, with 24,383 predicted genes. We associate most...

  5. Toward genome-scale models of the Chinese hamster ovary cells: incentives, status and perspectives

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder; Fan, Yuzhou; Weilguny, Dietmar

    2014-01-01

    Bioprocessing of the important Chinese hamster ovary (CHO) cell lines used for the production of biopharmaceuticals stands at the brink of several redefining events. In 2011, the field entered the genomics era, which has accelerated omics-based phenotyping of the cell lines. In this review we...

  6. Versatile microscale screening platform for improving recombinant protein productivity in Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Henning Gram; Nilsson, Claes Nymand; Lund, Anne Mathilde

    2015-01-01

    Chinese hamster ovary (CHO) cells are widely used as cell factories for the production of biopharmaceuticals. In contrast to the highly optimized production processes for monoclonal antibody (mAb)-based biopharmaceuticals, improving productivity of non-mAb therapeutic glycoproteins is more likely...

  7. The genomic sequence of the Chinese hamster ovary (CHO)-K1 cell line

    DEFF Research Database (Denmark)

    Xu, Xun; Pan, Shengkai; Liu, Xin

    2011-01-01

    Chinese hamster ovary (CHO)-derived cell lines are the preferred host cells for the production of therapeutic proteins. Here we present a draft genomic sequence of the CHO-K1 ancestral cell line. The assembly comprises 2.45 Gb of genomic sequence, with 24,383 predicted genes. We associate most of...

  8. Trends and approaches in N-Glycosylation engineering in Chinese hamster ovary cell culture

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    Chinese hamster ovary (CHO) cells have become the preferred expression system for the production of complex recombinantglycoproteins. It has been historically successful in industrial scale-up application and in generating human-like protein glycosylation.N-glycosylation of recombinant proteins......) omics-based characterization, 6) mathematical modelling....

  9. Humanizing recombinant glycoproteins from Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Anders Holmgaard; Amann, Thomas; Kol, Stefan

    hamster ovary (CHO) cells are making a very heterogeneous mixture of NGlycans. We speculate that the CHO pattern of N-Glycans would affect half-life and/or efficacy of the glycoprotein in the bloodstream making it unsuitable for human intravenous use, whereas our humanized version would be identical...

  10. Characterization of Chinese Hamster Ovary Cells Producing Coagulation Factor VIII Using Multi-omics Tools

    DEFF Research Database (Denmark)

    Kaas, Christian Schrøder

    The first public draft of a genome from Chinese hamster ovary (CHO) cells was published in 2011, an entire decade after the first draft of the human genome. This publication of a relevant CHO reference genome, in combination with the fact that the cost for DNA sequencing has dropped more than 10...... hamster origin. The transcriptome of 14 clones producing a dynamic range of FVIII was analyzed using RNA sequencing revealing an unexpected degree of 5’ truncations of the transgene in 11 of the 14 clones. These truncations were validated using targeted genome sequencing, which also mapped the transgene...

  11. Improving the secretory capacity of Chinese hamster ovary cells by ectopic expression of effector genes: Lessons learned and future directions

    DEFF Research Database (Denmark)

    Hansen, Henning Gram; Pristovsek, Nusa; Kildegaard, Helene Faustrup

    2017-01-01

    Chinese hamster ovary (CHO) cells are the preferred cell factory for the production of therapeutic glycoproteins. Although efforts primarily within bioprocess optimization have led to increased product titers of recombinant proteins (r-proteins) expressed in CHO cells, post-transcriptional bottle......Chinese hamster ovary (CHO) cells are the preferred cell factory for the production of therapeutic glycoproteins. Although efforts primarily within bioprocess optimization have led to increased product titers of recombinant proteins (r-proteins) expressed in CHO cells, post...

  12. Chinese hamster ovary mutant UV-1 is hypomutable and defective in a postreplication recovery process

    International Nuclear Information System (INIS)

    Stamato, T.D.; Hinkle, L.; Collins, A.R.; Waldren, C.A.

    1981-01-01

    CHO-UV-1 is a mutant of the Chinese hamster cell CHO-K1 hypersensitive to killing by ultraviolet light but with normal resistance to X-ray. It is also hypersensitive to killing by ethyl methane sulfonate. Hybrid clones formed bu fusing UV-1 and Chinese hamster lung cells display the normal ultraviolet resistance of the latter. The sensitive phenotype behaves, therefore, in a genetically recessive manner. Ultraviolet sensitivity of UV-1 is not associated with a deficiency in excision repair. Alkaline sucrose gradient sedimentation analysis of nascent DNA from ultraviolet-irradiated cells reveals that UV-1 is, however, markedly deficient in postreplication recovery. Furthermore, UV-1 has a lower rate of induced mutation to 6-thioguanine resistance than does the parental cell when treated with ultraviolet light or ethyl methane sulfonate. These results suggest that the phenotype of UV-1 is due to a mutation in a form of postreplication recovery which in normal cells is error prone

  13. Spontaneous mutation rate in Chinese hamster cell clones differing in UV-sensitivity

    International Nuclear Information System (INIS)

    Manuilova, E.S.; Bagrova, A.M.; Moskovskij Gosudarstvennyj Univ.

    1983-01-01

    The spontaneous rate of appearance of mutations to 6-mercaptopurine (6 MP) resistence in the cells of CHR2 and CHs2 clones dofferent in sensitivity to lethal and matagenous effect of UV-rays, is investigated. Increased UV-sensitivity of CHs2 clone is caused by the violation of postreplicative DNA reparation. It is established that the purity of spontaneously occuring mutations in both clones turns out to be similar, i.e. (1.5-1.8)x10 -5 for the cell pergeneration. It is shown that the effect of postreplicative DNA reparation in the cells of chinese hamster is not connected with the increase of spontaneous mutation ability. The problem on the possible role of reparation in the mechanism of appearance of spontaneous and induced mutations in the cells of Chinese hamster with increased UV-sensitivity is discussed

  14. In vivo genetic toxicity studies in Chinese hamsters fed irradiated or unirradiated foodstuffs

    International Nuclear Information System (INIS)

    Altmann, H.

    1982-01-01

    Two in vivo genetic toxicity studies were performed in Chinese hamsters fed irradiated or unirradiated diets of chicken, fish or dates in order to detect possible mutagenic effects caused by irradiating these foodstuffs. The tests selected for study were: 1. Chromosomal analysis of bone narrow cells and 2. DNA metabolism in spleen cells. Chicken, fish and dates were irradiated with doses of 7, 2.5 and 1 kGy respectively. These investigations were subsequently extended to include the effects of irradiated dried onions, pulses and cocoa beans on DNA metabolism in Chinese hamster spleen cells only. Dried onions were irradiated with doses of 0.15, 9 and 15 kGy, pulses with 10 kGy and cocoa beans with 3.2 to 5 kGy. In addition, a fumigated cocoa bean group was included. No significant differences in chromosomal aberration rate were detected between groups fed irradiated or unirradiated diets. Dried dates, whether irradiated or not, showed some evidence of genetic toxicity in their effect on DNA metabolism in the spleen cells of Chinese hamsters. Both date diets caused more strand breaks DNA than are usual for Chinese hamster spleen cells, but DNA repair was not adversely affected. Chicken, both irradiated and unirradiated, was found to enhance replicative DNA synthesis but had no effect on the DNA repair process. Irradiated fish, however, caused enhanced DNA synthesis compared to unirradiated fish, but also had no adverse effect on DNA repair. Irradiated white beans also enhanced DNA synthesis compared to controls whereas unirradiated samples inhibited synthesis. (orig./MG)

  15. The effect of hydroxyurea on synchronized Chinese hamster ovary cells irradiated by ultraviolet light

    International Nuclear Information System (INIS)

    Burg, K.; Collins, A.R.S.; Johnson, R.T.

    1979-01-01

    The effect of hydroxyurea (HU) on cell survival was investigated in Chinese hamster ovary cells after different radiation doses of UV light (254 nm) during the individual phases of the cell cycle. HU inhibits the repair DNA replication by mediation through the DNA precursor pool. These results are supported by the absence of the effect of HU both in the G2 phase possessing high levels of precursors and in supplying the 4 deoxyribonucleosides together with HU after irradiation

  16. Transfection of Chinese hamster ovary DHFR/sup -/ cells with the gene coding for heat shock protein 70 from drosophila melanogaster

    International Nuclear Information System (INIS)

    Duffy, J.J.; Carper, S.W.; Gerner, E.W.

    1987-01-01

    Chinese hamster ovary DHFR/sup -/ cells (CHO-DHFR/sup -/) were transfected with the plasmid pSV2-dhfr expressing the mouse gene coding for dhfr or with the same plasmid containing the gene coding for the Drosophila melanogaster heat shock protein 70 (hsp70), pSVd-hsp70. Three subcloned cell lines selected for expression of the dhfr gene were shown to contain either the vector sequence (G cells) or varying copies of pSVd-hsp70 (H cells). One line of H cells was shown to contain > 30 copies of the D. melanogaster hsp70 gene and to express the hsp70 RNA at significant levels. No difference between G and H cells was observed in the rate of growth, in the development of thermotolerance, or in the sensitivity of actin microfilament bundles to heat shock. However, H cells containing the transfected hsp70 gene had an altered morphology when compared to the G cells and the parental CHO-DHFR/sup -/ cells being more fibroblastic. The adhesion properties of the H cells was also decreased when compared to the G cells. These results show that insertion of the D. melanogaster gene into CHO cells does not effect growth rates or heat shock responses but may alter cell morphology and adhesion

  17. Recent progress with the DNA repair mutants of Chinese hamster ovary cells

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.H.; Salazar, E.P.; Brookman, K.W.; Collins, C.C.; Stewart, S.A.; Busch, D.B.; Weber, C.A.

    1986-04-02

    Repair deficient mutants of Chinese hamster ovary (CHO) cells are being used to identify human genes that correct the repair defects and to study mechanisms of DNA repair and mutagenesis. Five independent tertiary DNA transformants were obtained from the EM9 mutant. In these clones a human DNA sequence was identified that correlated with the resistance of the cells to CldUrd. After Eco RI digestion, Southern transfer, and hybridization of transformant DNAs with the BLUR-8 Alu family sequence, a common fragment of 25 to 30 kb was present. 37 refs., 4 figs., 3 tabs.

  18. Postreplication gap filling in the DNA of X-ray-damaged Chinese hamster cells

    International Nuclear Information System (INIS)

    Koerner, I.; Malz, W.

    1975-01-01

    In X-irradiated Chinese hamster cells the newly synthesized DNA has a lower molecular weight than the DNA in control cells. This reduced molecular weight has been interpreted by gap induction opposite the lesions in the parental DNA strands. Within two hours these postreplication gaps were closed. With the aid of BrdUrd-photolys-technique it could be demonstrated that the gaps were filled by de novo synthesis. But we were not able to show a participation of parental DNA in the gap-filling process

  19. Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents.

    OpenAIRE

    Kaina, B; Lohrer, H; Karin, M; Herrlich, P

    1990-01-01

    Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of re...

  20. Recent progress with the DNA repair mutants of Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Thompson, L.H.; Salazar, E.P.; Brookman, K.W.; Collins, C.C.; Stewart, S.A.; Busch, D.B.; Weber, C.A.

    1986-01-01

    Repair deficient mutants of Chinese hamster ovary (CHO) cells are being used to identify human genes that correct the repair defects and to study mechanisms of DNA repair and mutagenesis. Five independent tertiary DNA transformants were obtained from the EM9 mutant. In these clones a human DNA sequence was identified that correlated with the resistance of the cells to CldUrd. After Eco RI digestion, Southern transfer, and hybridization of transformant DNAs with the BLUR-8 Alu family sequence, a common fragment of 25 to 30 kb was present. 37 refs., 4 figs., 3 tabs

  1. Variations in sensitivity of synchronized Chinese hamster cells to oxic and anoxic X-ray exposures

    International Nuclear Information System (INIS)

    Siracka, E.; Littbrand, B.; Clifton, K.H.; Revesz, L.

    1975-01-01

    V-79 Chinese hamster cells in monolayer cultures on glass surfaces were synchronized by treatment with hydroxyurea and then exposed at different times to X-rays in air or in oxygen-free argon. Survival determinations indicated that the oxygen enhancement ratio (OER) as expressed by the ratio of the respective D 0 values varied over a narrow range in the different phases of the cell cycle. These changes resulted from cyclic alterations in both aerobic and anaerobic D 0 values, possibly in n values. (author)

  2. Cell killing and mutation induction on Chinese hamster cells by photoradiations

    International Nuclear Information System (INIS)

    Lam, C.K.C.

    1982-11-01

    Applying radiation directly on cells, far-uv is more effective than black light, and black light is more effective than white light in inducing proliferative death and in inducing resistance to 6-thioguanine (6-TG), ouabain and diptheria toxin (DT). Gold light has no killing and mutagenic effects on CHO (Chinese hamster ovary) cells. Use of filters showed that a small percentage of shorter wavelengths in the far-uv region is responsible for most of the killing and mutagenic effects in the unfiltered broad spectra of black and white light

  3. Recovery from DNA synthesis in V 79 chinese hamster cells irradiated with UV light

    International Nuclear Information System (INIS)

    Ventura, A.M.

    1987-01-01

    Mammalian cells recover from DNA synthesis inhibition by UV light before most of the pyrimidine dimers have been removed from the genome. Most of the rodent cells show a deficient dimer excision repair compared with normal human fibroblasts. Despite this fact they recover efficiently from DNA synthesis inhibition after UV. In Chinese hamster V 79 cells was found that this recovery takes place in the absence of a significant excision repair, and it seems to be directly coupled to a recovery in the rate of movement of the replication fork. 120 refs, 31 figs. (author)

  4. Saccharin-induced sister chromatid exchanges in Chinese hamster and human cells

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, S.; Rodin, B.

    1978-05-05

    Since the induction of sister chromatid exchanges in cultured cells has been shown to be the most sensitive mammalian system to detect the effects of mutagenic carcinogens, Chinese hamster ovary cells and human lymphocytes were exposed to the sodium saccharin found to induce bladder cancer in rats. Both that saccharin and a highly purified extract of it increased the yield of sister chromatid exchanges in both types of cells. The results, which were repeatable and statistically highly significant, indicated that the weak carcinogen, saccharin, is also mutagenic in the sense that it induces cytogenetic changes.

  5. Intracellular pH in increased after transformation of Chinese hamster embryo fibroblasts

    International Nuclear Information System (INIS)

    Ober, S.S.; Pardee, A.B.

    1987-01-01

    These studies reveal that a series of tumorigenic Chinese hamster embryo fibroblast (CHEF) cell lines maintain an internal pH (pH/sub i/) that is 0.12 +/- 0.04 pH unit above that of the nontumorigenic CHEF/18 parental line. pH measurements were made with [ 14 C]-benzoic acid. This increase of pH/sub i/ in the tumorigenic CHEF cells is not due to autocrine growth factor production or to the persistent activation of pathways previously shown to modulate Na + /H + -antiporter activity present in the CHEF/18 line. These findings suggest that the defect in pH/sub i/ regulation in the tumorigenic CHEF/18 derivatives lies in the Na + /H + antiporter itself. Further studies to determine the biological significance of an increased pH/sub i/ show that the external pH (pH 0 )-dependence curve for initiation of DNA synthesis in the tumorigenic CHEF lines is shifted by approximately 0.2 pH unit toward acidic values relative to that of the nontumorigenic CHEF/18 parent. These data show a critical role for pH/sub i/ in the regulation of DNA synthesis in Chinese hamster embryo fibroblasts and demonstrate that aberrations in pH/sub i/ can contribute to the acquisition of altered growth properties

  6. Isolation and characterization of variant clones of Chinese hamster cells after treatment with irradiated 5-iodouridine

    International Nuclear Information System (INIS)

    Kuroda, Y.; Yokoiyama, A.; Kada, T.

    1975-01-01

    Variant clones were isolated from cultured Chinese hamster Don cells after treatment with irradiated 5-iodouridine. The following characters of a primary variant clone, C-11 and a secondary variant clone, C-24 were compared with those of the original clone C-1: colony-forming activity, growth rate in the presence of irradiated and unirradiated 5-iodouridine, distribution of chromosome numbers and cell cohesion. The variant clones C-11 and C-24 were partially resistant to unirradiated 5-iodouridine at lower concentration and C-24 cells were slightly resistant to short-term treatment with irradiated 5-iodouridine. Unlike clones C-1 and C-11, the variant clone C-24 showed no lag phase on growth in 5-iodouridine medium. The modal numbers of the chromosomes of all three clones were 22, like that of normal Chinese hamster diploid cells. Of the three clones, the variant C-24 cells showed the least mutual cohesion and the original C-1 cells showed the most. The possibility that an alteration in cellular membrane might be related to an increase in the resistance to radiosensitizing agents was discussed

  7. Phenolphthalein induces chromosome aberrations in human and Chinese hamster liver cells (CHEL) cultured in vitro.

    Science.gov (United States)

    Biondi, O; Andreozzi, L; Amoruso, S; Motta, S

    2000-01-01

    Phenolphthalein is a nonprescription laxative agent that has been widely used during this century. Recent studies in animal models have shown that phenolphthalein has carcinogenic activity. In order to assess cytogenetic effects on human cells in vitro, we tested phenolphthalein in a chromosome aberration assay in human embryo cells derived from amniotic fluid. Our results show that phenolphthalein induces a significant increase in the frequency of chromosome aberrations in human cells. The lowest dose level at which the clastogenic effect is evident is 23.2 microg/ml. Similar positive results were obtained in a Chinese hamster liver cell line, which is metabolically competent to activate different classes of promutagens and procarcinogens into biologically active metabolites. Instead, parallel experiments in Chinese hamster ovary cells did not show any clastogenic effect due to phenolphthalein. These latter data suggested that phenolphthalein acts as a promutagen and must be metabolically activated to exert its clastogenic effect. Teratogenesis Carcinog. Mutagen. 20:209-217, 2000. Copyright 2000 Wiley-Liss, Inc.

  8. Quantitative feature extraction from the Chinese hamster ovary bioprocess bibliome using a novel meta-analysis workflow

    DEFF Research Database (Denmark)

    Golabgir, Aydin; Gutierrez, Jahir M.; Hefzi, Hooman

    2016-01-01

    The scientific literature concerning Chinese hamster ovary (CHO) cells grows annually due to the importance of CHO cells in industrial bioprocessing of therapeutics. In an effort to start to catalogue the breadth of CHO phenotypes, or phenome, we present the CHO bibliome. This bibliographic...

  9. Multi-omic profiling of EPO-producing Chinese hamster ovary cell panel reveals metabolic adaptation to heterologous protein production

    DEFF Research Database (Denmark)

    Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

    2015-01-01

    Chinese hamster ovary (CHO) cells are the preferred production host for many therapeutic proteins. The production of heterologous proteins in CHO cells imposes a burden on the host cell metabolism and impact cellular physiology on a global scale. In this work, a multi-omics approach was applied...

  10. Interphase death of dividing cells. Kinetics of death of cultured Chinese hamster fibroblasts after irradiation with various doses

    International Nuclear Information System (INIS)

    Kublik, L.N.; Veksler, A.M.; Ehjdus, L.Kh.

    1989-01-01

    In studying the kinetics of interphase death (ID) of cultured Chinese hamster cells after irradiation with doses of 100 to 800 Gy the authors showed an increase in the ID rate with increasing radiation dose; the presence of serum in the medium both during and after irradiation prevents the cell death

  11. Modification of potentially lethal damage in irradiated Chinese hamster V79 cells after incorporation of halogenated pyrimidines

    NARCIS (Netherlands)

    Franken, N. A.; van Bree, C. V.; Kipp, J. B.; Barendsen, G. W.

    1997-01-01

    Radiosensitization of exponentially growing and plateau phase Chinese hamster V79 cells by incorporation of halogenated pyrimidines (HP) was investigated for different culture conditions that influenced repair. For this purpose cells were grown for 72 h with 0, 1, 2 and 4 microM of chloro-(CldUrd),

  12. The influence of the wavelength of ultraviolet radiation on survival, mutation induction and DNA repair in irradiated Chinese hamster cells

    NARCIS (Netherlands)

    Zelle, B.; Reynolds, R.J.; Kottenhagen, M.J.; Schuite, A.; Lohman, P.H.M.

    1980-01-01

    Chinese hamster ovary cells were used to compare the cytotoxicity and mutagenicity of far-UV radiation emitted by a low-pressure mercury, germicidal lamp (wavelength predominantly 254 nm) with that of near-UV radiation emitted by a fluorescent lamp with a continuous spectrum (Westinghouse 'Sun

  13. Adriamycin resistance, heat resistance and radiation response in Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Wallner, K.; Li, G.

    1985-01-01

    Previous investigators have demonstrated synergistic interaction between hyperthermia and radiation or Adriamycin (ADR), using cell lines that are sensitive to heat or ADR alone. The authors investigated the effect of heat, radiation or ADR on Chinese hamster fibroblasts (HA-1), their heat resistant variants and their ADR resistant variants. Heat for ADR resistance did not confer cross resistance to radiation. Cells resistant to heat did show cross resistance to ADR. While cells selected for ADR resistance were not cross resistant to heat, they did not exhibit drug potentiation by hyperthermia, characteristic of ADR sensitive cells. Cytofluorometric measurement showed decreased ADR uptake in both heat and ADR resistant cells. The possibility of cross resistance between heat and ADR should be considered when designing combined modality trials

  14. Glycoengineering of Chinese hamster ovary cells for enhanced erythropoietin N-glycan branching and sialylation

    DEFF Research Database (Denmark)

    Yin, Bojiao; Gao, Yuan; Chung, Cheng-yu

    2015-01-01

    -glycosylation of recombinant erythropoietin (rEPO), a human α2,6-sialyltransferase (ST6Gal1) was expressed in Chinese hamster ovary (CHO-K1) cells. Sialylation increased on both EPO and CHO cellular proteins as observed by SNA lectin analysis, and HPLC profiling revealed that the sialic acid content of total glycans on EPO......EPO from these engineered cells was increased ∼45% higher with tetra-sialylation accounting for ∼10% of total sugar chains compared to ∼3% for the wild-type parental CHO-K1. In this way, coordinated overexpression of these three glycosyltransferases for the first time in model CHO-K1 cell lines provides...

  15. Isolation of hypoxanthine phosphoribosyltransferase-defective mutants in Chinese hamster V79 cells by tritium suicide

    International Nuclear Information System (INIS)

    Bryant, R.E.; Schauer, I.E.; Hatcher, D.G.

    1981-01-01

    Tritium suicide was shown to be a highly efficient method for isolating mutants defective in hypoxanthine incorporation in the Chinese hamster lung of one kill cycle were used for the next kill cycle. The kill cycles involved incorporation of ( 3 H) hypoxanthine for 5 or 10 min, followed by storage of 3 H-labelled cells at -70 0 C for 4-10 days. 12 clones that survived the 3rd kill cycle were tested for incorporation of ( 3 H)hypoxanthine and all were found to be defective. At least 6 of the clones have defective hypoxanthine phosphoribosyltransferase (HPRT) activity. One mutant, H19, chosen for further characterization, had HPRT with a 13-fold elevation in apparent Ksub(m) for phosphoribosylpyrophosphate (PRPP). Thin-layer chromatography of cell extracts showed that this mutant was incapable of converting intracellular hypoxanthine to IMP or to other purine metabolites. In addition, H19 was resistant to 6-thioguanine. (orig.)

  16. Comparative mutagenicity of alkylsulfate and alkanesulfonate derivatives in Chinese hamster ovary cells.

    Science.gov (United States)

    Couch, D B; Forbes, N L; Hsie, A W

    1978-05-01

    Mutation induction and cell killing produced by selected alkylsulfates and alkanesulfonates have been quantitated using the Chinese hamster ovary/hypoxanthine--guanine phosphoribosyl transferase (CHO/HGPRT) system. Dose--response relationships of cytotoxicity and mutagenicity are presented for two alkylsulfates [dimethylsulfate (DMS), diethylsulfate (DES)] and three alkyl alkanesulfonates [methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), and isopropyl methanesulfonate (iPMS)]. Under the experimental conditions employed, cytotoxicity decreased with the size of the alkyl group. DMS was more toxic than DES, and MMS was more toxic than EMS and iPMS. All agents produced linear dose--response of mutation induction: DMS was more mutagenic than DES, and MMS was more mutagenic than EMS and iPMS based on mutants induced per unit mutagen concentration. However, the following relative mutagenic potency was observed when comparisons were made at 10% survival: DES greater than DMS; EMS greater than MMS greater than iPMS.

  17. Effects of x rays on DNA synthesis in synchronized Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Laughlin, T.J.; Taylor, J.H.

    1980-01-01

    Chinese hamster ovary cells were synchronized at the beginning of S phase with 5-fluorodeoxyuridine and irradiated with moderte levels ( 3 H]thymidine at various times after irradiation. The cells were lysed immediately after termination of the pulse, and the rate of DNA synthesis, size of the nascent strands, and number of active replicons were determined. The level of DNA synthesis in cells pulse-labeled immediately after x irradiation with 1000 rad was suppressed 20 to 25% but returned to control levels within 4 h after irradiation. Our data demonstrate that this x-ray-induced suppression of DNA synthesis was due entirely to a reduction in the number of active replicons, with no appreciable change in the rate of chain growth

  18. Mutation of Chinese hamster cells by near-UV activation of promutagens

    International Nuclear Information System (INIS)

    Barnhart, B.J.; Cox, S.H.

    1980-01-01

    A tissue-culture assay for mutagenesis and cytotoxicity incorporating near ultraviolet (NUV) light activation of polyaromatic hydrocarbons (PAH) has been developed. Cultures of Chinese hamster cells (line CHO) growing in suspension culture were inoculated with benzo[a]pyrene (B[a]P), 7,12-dimethylbenzanthracene (DMBA) or shale-oil retort-water and exposed to light from a high-pressure mercury lamp fitted with a Corning NUV bandpass filter. This light source both permitted activation of PAH and the shale-oil water and precluded detectable damage to DNA. Neither the PAH nor the NUV alone had any effect on cell survival or mutation frequencies but the chemicals plus NUV were extremely effective in producing mutations to 6-thioguanine resistance (hgprt gene). (orig.)

  19. Analysis of Chinese hamster ovary cell metabolism through a combined computational and experimental approach.

    Science.gov (United States)

    Chen, Ning; Bennett, Mark H; Kontoravdi, Cleo

    2014-12-01

    Optimization of cell culture processes can benefit from the systematic analysis of experimental data and their organization in mathematical models, which can be used to decipher the effect of individual process variables on multiple outputs of interest. Towards this goal, a kinetic model of cytosolic glucose metabolism coupled with a population-level model of Chinese hamster ovary cells was used to analyse metabolic behavior under batch and fed-batch cell culture conditions. The model was parameterized using experimental data for cell growth dynamics, extracellular and intracellular metabolite profiles. The results highlight significant differences between the two culture conditions in terms of metabolic efficiency and motivate the exploration of lactate as a secondary carbon source. Finally, the application of global sensitivity analysis to the model parameters highlights the need for additional experimental information on cell cycle distribution to complement metabolomic analyses with a view to parameterize kinetic models.

  20. Cloning and Expression of Luteinizing Hormone Subunits in Chinese Hamster Ovary Cell Line

    Directory of Open Access Journals (Sweden)

    Zeinab Soleimanifar

    2016-10-01

    Full Text Available Background: Luteinizing hormone (LH was secreted by the stimulating cells of the testes and ovaries in the anterior pituitary gland. The application of this hormone is in the treatment of men and women with infertility and amenorrhea respectively.Materials and Methods: In the present study the alpha and beta subunits of human LH gene were cloned into the pEGFP-N1 expression vector and produced the recombinant LH hormone in Chinese hamster ovary (CHO eukaryotic system.Results: Alpha and beta subunits of LH hormone were cloned between NheI and BamHI cut sites of pEGFP_N1 expression plasmid and confirmed by PCR.  Hormone expression was evaluated in CHO cell line by Western blotting using the specific antibody.Conclusion: Alpha and beta subunits of LH hormone were expressed in CHO cell line perfectly.

  1. UV-induced chromatid aberrations in two cell linear of Chinese hamster with different repair activity

    International Nuclear Information System (INIS)

    Ikushima, Takaji

    1978-01-01

    To elucidate the mechanism of chromosomal aberration formation, the yield and type of chromosomal aberrations induced by ultraviolet light (UV) irradiation were compared in cultured Chinese hamster cells with different repair activity. After irradiation of low fluences of UV, chromatid aberrations were produced more frequently in one cell line with impaired repair activity, B14FAF than the other showing normal DNA repair replication, CHO. There were no difference in the spectrum of the aberration types between the two. The results imply that impaired excision repair of UV-induced pyrimidine dimers or other photoproducts results in higher yield of chromosomal aberrations, and suggest the involvement of DNA repair processes in chromosomal aberration formation. (author)

  2. Unique biophysical studies with diatomic deuterium beams. [Survival studies with V79 Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohrig, N.; Bird, R.P.; Colvett, R.D.; Rossi, H.H.; Marino, S.A.

    1978-01-01

    By irradiating cells attached to thin Mylar foils with diatomic deuteron beams, the role of interaction distance in radiobiology can be investigated in a unique manner. The molecule breaks up into two separate ions which diverge from each other because of the multiple scattering process in the foil and in the cellular material. A distribution of separation distances results whose characteristic separation depends on the Mylar foil thickness. An experimental facility to use diatomic beams is described. Cell survival results for V79 Chinese hamster cells synchronized in late S phase show that damage does result from tracks separated by as much as 250 nm. However, damage also results from interaction at nanometer dimensions.

  3. Effects of harman and norharman on spontaneous and ultraviolet light-induced mutagenesis in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Chang, C.C.; Castellazzi, M.; Glover, T.W.; Trosko, J.E.

    1978-01-01

    Nontoxic concentrations of harman and norharman were tested in cultured Chinese hamster cells for their effects on DNA repair and mutagenesis. The following effects of harman were observed: (a) the survival of ultraviolet light- or x-ray-damaged cells was reduced; (b) the ultraviolet light-induced unscheduled DNA synthesis was slightly inhibited; and (c) the frequency of spontaneous or ultraviolet light-induced ouabain-resistant (ouar) or 6-thioguanine-resistant (6-TGr) mutations was reduced. Furthermore, the effect of harman on survival and mutagenesis was greater than that of norharman and was detected primarily in treatments in which cells were exposed to harman immediately following ultraviolet light irradiation. Our data clearly indicate that harman decreases the capacity to repair DNA damage and fix mutations in Chinese hamster cells, possibly because of the intercalation properties of this compound

  4. Observation of Chinese Hamster Ovary Cells retained inside the non-woven fiber matrix of the CellTank bioreactor.

    Science.gov (United States)

    Zhang, Ye; Chotteau, Véronique

    2015-12-01

    This data article shows how the recombinant Chinese Hamster Ovary (CHO) cells are located in the interstices of the matrix fibers of a CellTank bioreactor after completion of a perfusion culture, supporting the article entitled "Very high cell density perfusion of CHO cells anchored in a non-woven matrix-based bioreactor" by Zhang et al. [1]. It provides a visualization of the cell distribution in the non-woven fiber matrix in a deeper view.

  5. The essential structures of ISP-I that influence serine palmitoyltransferase inhibition in Chinese hamster ovary cells.

    Science.gov (United States)

    Mizukoshi, Koji; Matsumoto, Katsuo; Hirose, Ryoji; Fujita, Tetsuro

    2012-01-01

    We investigated the structure-activity relationship between various ISP-I (myriocin, thermozymocidin) analogous which has sphingosine-like structure and serine palmitoyltransferase (SPT) in Chinese hamster ovary (CHO) cells utilizing sphingolipid production as a marker. Our data suggest that the double bond and/or ketone group within the alkyl chain as well as the alkyl chain are necessary for ISP-I to inhibit SPT. In addition, a serine structure is necessary for SPT inhibitory activity, which confirms previous findings.

  6. Observation of Chinese Hamster Ovary Cells retained inside the non-woven fiber matrix of the CellTank bioreactor

    OpenAIRE

    Zhang, Ye; Chotteau, V?ronique

    2015-01-01

    This data article shows how the recombinant Chinese Hamster Ovary (CHO) cells are located in the interstices of the matrix fibers of a CellTank bioreactor after completion of a perfusion culture, supporting the article entitled “Very high cell density perfusion of CHO cells anchored in a non-woven matrix-based bioreactor” by Zhang et al. [1]. It provides a visualization of the cell distribution in the non-woven fiber matrix in a deeper view.

  7. Effects of turmeric and its active principle, curcumin, on bleomycin-induced chromosome aberrations in Chinese hamster ovary cells

    OpenAIRE

    Araújo, Maria Cristina P.; Dias, Francisca da Luz; Kronka, Sergio N. [UNESP; Takahashi, Catarina S.

    1999-01-01

    Naturally occurring antioxidants have been extensively studied for their capacity to protect organisms and cells from oxidative damage. Many plant constituents including turmeric and curcumin appear to be potent antimutagens and antioxidants. The effects of turmeric and curcumin on chromosomal aberration frequencies induced by the radiomimetic agent bleomycin (BLM) were investigated in Chinese hamster ovary (CHO) cells. Three concentrations of each drug, turmeric (100, 250 and 500 mg/ml) and ...

  8. Transgenic Chinese hamster V79 cell lines which exhibit variable levels of gpt mutagenesis

    International Nuclear Information System (INIS)

    Klein, C.B.; Rossman, T.G.

    1990-01-01

    The Escherichia coli gpt gene coding for xanthine-guanine phosphoribosyl transferase has been stably transfected into HPRT - Chinese hamster V79 cells. Several gpt - cell lines have been established, which retain the sequence(s) even after long-term culture without selection for gpt. While spontaneous mutagenesis to gpt - occurs rather frequently for most cell lines, it cannot be correlated with either the number of plasmid integration sites or deletion of the plasmid sequence(s). One transgenic cell line (g12), which continuously maintains a low spontaneous mutation frequency was used in comparative mutagenesis studies with wild-type V79 cells (gpt vs. hprt). Alkylating agents such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and β-propiolactone (BPL) are shown to be equally toxic and mutagenic in both g12 and V79 cells. UV and X-rays are also equally toxic to both cell lines. The data presented here suggests that g12 cells may be useful to study mammalian mutagenesis by agents which yield limited response at the hprt locus

  9. Potentially lethal damage versus sublethal damage: independent repair processes in actively growing Chinese hamster cells

    International Nuclear Information System (INIS)

    Utsumi, H.; Elkind, M.M.

    1979-01-01

    Actively growing V79 Chinese hamster cells, treated with anisotonic phosphate-buffered saline (PBS) after x irradiation, are more sensitive than cells treated with isotonic PBS or cells promptly incubated with complete medium immediately after irradiation. The sensitization of irradiated cells results from hypotonic as well as hypertonic NaCl concentrations in PBS, is strongly dependent on both temperature and time, and is mainly due to an increase in the final slope of the single-dose survival curve. After two x-ray dose fractions, the net response of cells sensitized after each fraction by anisotonic post-treatment is similar to that obtained for isotonically treated cells and indicates that sublethal damage repair is not influenced by the enhanced expression of lethal damage. Independence of the repair of damage which is potentially lethal from the repair of damage which is sublethal is further suggested by the more rapid rate of the former compared to that of the latter. The proposal is advanced that the enhanced expression of damage which, after x irradiation, can be shown to be potentially lethal results from a destabilization of the structural relationship between DNA and the nuclear envelope, and/or DNA and the nuclear protein matrix, as a consequence of osmotic changes produced by anisotonic treatment

  10. Genetic effects of the flavonols quercetin, kaempferol, and galangin on Chinese hamster ovary cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Carver, J.H. (Lawrence Livermore National Lab., Livermore, CA); Carrano, A.V.; MacGregor, J.T.

    1983-01-01

    The genotoxicity of selected flavonols was evaluated by multiple endpoints in Chinese hamster ovary (CHO) cells. Chromosomal aberrations, sister-chromatid exchange (SCE), and forward mutation at 4 gene loci were measured in a single population of cells exposed to quercetin, kaempferol, or galangin for 15 h with and without metabolic activation. The incidence of chromosomal aberrations was significantly increased by quercetin in the absence of activation and by kaempferol and galangin with and without activation. Flavanol treatment affected SCE and mutation at the hgprt, aprt, or Na/sup +//K/sup +/-ATPase loci only marginally, but significantly increased mutation frequencies at the tk locus. The response at the tk locus suggests that the CHO cells may behave similarly to L5178Y cells, in which the tk locus is thought to reflect chromosomal lesions in addition to point mutation. These results indicate that, at least under the conditions examined, flavonols induce chromosomal aberrations in CHO cells, but have little effect on point mutation or SCE.

  11. Expression of a human gene for polyamine transport in Chinese-hamster ovary cells.

    Science.gov (United States)

    Byers, T L; Wechter, R; Nuttall, M E; Pegg, A E

    1989-01-01

    A molecular-genetic approach towards isolating mammalian polyamine-transport genes and their encoded proteins was devised involving the production of Chinese-hamster ovary (CHO) cells expressing a human polyamine-transport protein. CHO cells and a polyamine-transport-deficient CHO mutant cell line (CHOMG) were equally sensitive to the antiproliferative effects of alpha-difluoromethylornithine (DFMO), which blocked endogenous polyamine synthesis. Exposure to exogenous polyamines increased intracellular polyamine levels and reversed this DFMO-induced cytostasis in the CHO cells, but not in the CHOMG cells. CHOMG cells were therefore transfected with human DNA (isolated from HT-29 colon carcinoma cells) and cells expressing the human polyamine-transport system were identified by the ability of these cells to grow in a medium containing DFMO and polyamines. A number of different positive clones were identified and shown to have the capacity for polyamine uptake and an increased sensitivity to the toxic effects of the polyamine analogue methylglyoxal bis(guanylhydrazone). Differences in these properties between the clones are consistent with a multiplicity of polyamine-transport systems. Some clones also showed a change in growth characteristics, which may indicate a relationship between genes involved in the polyamine-transport system and in cell proliferation. PMID:2512913

  12. The mutation studies of mutagen-sensitive and DNA repair mutants of Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Schultz, R.A.; Chang, C.C.; Trosko, J.E.

    1981-01-01

    We have previously reported the isolation and partial characterization of DNA repair and/or mutagen-sensitive mutant Chinese hamster cell strains. Here we present the results of a detailed study of the ultraviolet light (UV)-induced mutability of one of these strains, UVs-7, and provide preliminary mutability data on two additional lines, UVr-23 and UVs-40. UVs-7 in extremely deficient in unscheduled DNA synthesis (UDS) but only slightly more sensitive to UV than the parental line. When examined for the UV-inducibility of mutants resistant to ouabain, 6-thioguanine, or diphtheria toxin, UVs-7 was found to be hypermutable at all three loci as compared to the parental line. The degree of hypermutability was not the same for any two loci. UVs-40, a highly UV-sensitive strain, was also found to be hypermutable at the ouabain-resistant (ouar) locus. UVr-23, which is UV-resistant and more proficient at UDS than the parental line, appeared to exhibit a tendency toward hypomutability at both the ouabain(ouar) and 6-thioguanine--resistant (6TGr) loci. Further characterization of all these lines should aid in delineating mammalian mechanisms of DNA repair and mutagenesis

  13. Caffeine-enhanced survival of radiation-sensitive, repair-deficient Chinese hamster cells

    International Nuclear Information System (INIS)

    Utsumi, H.; Elkind, M.M.

    1983-01-01

    A clone of V79 Chinese hamster cells (V79-AL162/S-10) with unique properties has been isolated after a challenge of parental cells (V79-AL162) with 1 mM ouabain. Compared with parental cells, or with other clones isolated after the ouabain challenge, these cells form smaller colonies, are more sensitive to both x rays and fission-spectrum neutrons, and respond atypically to a postirradiation treatment with caffeine. Their enhanced response to x rays results mainly from a large reduction in the shoulder of their survival curve, probably because in late S phase, the most resistant phase in the cell cycle, the survival curve of these cells has a reduced shoulder width. Caffeine, and to a lesser extent theophylline, added to the colony-forming medium immediately after exposure appreciably increases the width of the shoulder of these sensitive cells, whereas caffeine has the opposite effect on the response of normal V79 cells. Thus the unique response of the V79-AL162/S-10 cells to a radiation posttreatment with caffeine (increased survival) results from a net increase in their ability to repair damage that is otherwise lethal; caffeine treatment ordinarly prevents normal V79 cells from repairing damage that is only potentially lethal

  14. Radiation-induced mutagenicity in repair deficient Chinese hamster ovary (CHO) mutants

    International Nuclear Information System (INIS)

    Tesmer, J.G.; Saunders, E.H.; Chen, D.J.

    1987-01-01

    To determine if there is a relationship between DNA double-strand break repair and mutagenicity the authors utilized two x-ray sensitive mutants of Chinese hamster ovary cells along with the parental line K1. The two mutant lines xrs-5 and xrs-6, which have different DSB repair capabilities, were used to determine cell killing and 6-thioguanine resistance (6TG/sup r/) mutation frequencies induced by either x-rays of α-particles, x-ray survival data indicated the two mutant lines have similar sensitivity and are 5-7 fold more sensitive than the parental line K1. The mutant lines are also sensitive to α-particles but to a lesser extent. The authors' 6TG mutation data indicated that the two mutant lines are hypermutable. When mutation frequencies were plotted against the log of survival, mutation frequency at a given survival level was greater in mutant cell population than in parental K1 cells. Their results support the notion that repair of DSB play an important role in the expression of radiation-induced cell killing and mutagenicity

  15. Evidence for multiple repair pathways of double-strand DNA breaks in Chinese hamster cells

    International Nuclear Information System (INIS)

    Giaccia, A.J.; Weistein, R.; Stamato, T.D.; Roosa, R.

    1984-01-01

    XR-1 is a mutant of the Chinese hamster cell (CHO-K1) which is abnormally sensitive to killing by gamma rays in G/sub 1/ (D37 = 27 rads vs. 318 for parent) and early S phases of the cell cycle but has near normal resistance in late S and early G/sub 2/ (Somatic Cell Genetics, 9:165-173, 1983). Complementation studies between XR-1 and its parent indicate that this sensitivity to gamma rays is a recessive phenotype. Both the XR-1 and its parent cell are able to repair single strand DNA breaks. However, in comparison to its parental cell, the XR-1 cell is markedly deficient in the repair of double strand DNA breaks introduced by gamma irradiation during the sensitive G/sub 1/-early S period, while in the late S-G/sub 2/ resistant period the repair is similar in both cells. This correlation suggests that an unrepaired double strand DNA break is the lethal lesion and that at least two pathways for the repair of these lesions exist in mammalian cells

  16. Isolation and characterization of a radiosensitive Chinese hamster ovary cell line

    International Nuclear Information System (INIS)

    Fuller, L.F.

    1987-01-01

    A x-ray sensitive Chinese hamster ovary cell line was isolated using a semi-automated procedure in which mutagenized CHO cells were allowed to form colonies on top of agar, x-irradiated, then photographed at two later times. Comparison of the photographs allowed the identification of colonies which displayed significant growth arrest. One of the colonies identified in this manner produced a stable, radiosensitive line. This cell line is normal in x-ray induced inhibition of DNA synthesis, and single- and double-strand break repair, and is moderately sensitive to ethyl methane sulfonate and UV light. The sensitive line performs only half as much x-ray-induced repair replication as the parental line and this deficiency is believed to be the primary cause of its radiosensitivity. The sensitive line produces significantly higher numbers of x-ray-induced chromosome and chromatid aberrations including chromatid aberrations following exposure during the G 1 phase of the cell cycle. The line is hypomutable compared to the parental line with x-ray exposure inducing only one-third as many 6-thioguanine resistant colonies

  17. Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents

    International Nuclear Information System (INIS)

    Kaina, B.; Lohrer, H.; Karin, M.; Herrlich, P.

    1990-01-01

    Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of reduced glutathione synthesis, the transfectants were not more resistant to the lethal effects of ionizing radiation and bleomycin than the parent cells. Thus free radicals generated by these agents cannot be scavenged efficiently by MT in vivo. The hMT-IIA transfectants, however, but not control transfectants harboring a BPV-MT promoter-neo construct, tolerated significantly higher doses of the alkylating agents N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Resistance and MT overexpression occurred irrespective of selection and cultivation in cadmium and zinc. There was no increase in resistance to methyl methanesulfonate and N-hydroxyethyl-N-chloroethylnitrosourea. MT did not affect the degree of overall DNA methylation after N-methyl-N-nitrosourea treatment nor the level of O6-methylguanine-DNA methyltransferase. The results suggest that MT participates as a cofactor or regulatory element in repair or tolerance of toxic alkylation lesions

  18. Isolation of cell cycle-dependent gamma ray-sensitive Chinese hamster ovary cell

    International Nuclear Information System (INIS)

    Stamato, T.D.; Weinstein, R.; Giaccia, A.; Mackenzie, L.

    1983-01-01

    A technique for the isolation of gamma ray-sensitive Chinese hamster ovary (CHO) cell mutants is described, which uses nylon cloth replica plating and photography with dark-field illumination to directly monitor colonies for growth after gamma irradiation. Two gamma ray-sensitive mutants were isolated using this method. One of these cells (XR-1) had a two-slope survival curve: an initial steep slope and then a flattening of the curve at about 10% survival. Subsequently, it was found that this cell is sensitive to gamma irradiation in G1, early S, and late G2 phases of the cell cycle, whereas in the resistant phase (late S phase) its survival approaches that of the parental cells. The D37 in the sensitive G1 period is approximately 30 rads, compared with 300 rads of the parental cell. This mutant cell is also sensitive to killing by the DNA breaking agent, bleomycin, but is relatively insensitive to UV light and ethyl methane sulfonate, suggesting that the defect is specific for agents that produce DNA strand breakage

  19. Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents

    Energy Technology Data Exchange (ETDEWEB)

    Kaina, B.; Lohrer, H.; Karin, M.; Herrlich, P. (Kernforschungszentrum Karlsruhe, Karlsruhe (Germany, F.R.))

    1990-04-01

    Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of reduced glutathione synthesis, the transfectants were not more resistant to the lethal effects of ionizing radiation and bleomycin than the parent cells. Thus free radicals generated by these agents cannot be scavenged efficiently by MT in vivo. The hMT-IIA transfectants, however, but not control transfectants harboring a BPV-MT promoter-neo construct, tolerated significantly higher doses of the alkylating agents N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Resistance and MT overexpression occurred irrespective of selection and cultivation in cadmium and zinc. There was no increase in resistance to methyl methanesulfonate and N-hydroxyethyl-N-chloroethylnitrosourea. MT did not affect the degree of overall DNA methylation after N-methyl-N-nitrosourea treatment nor the level of O6-methylguanine-DNA methyltransferase. The results suggest that MT participates as a cofactor or regulatory element in repair or tolerance of toxic alkylation lesions.

  20. Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents.

    Science.gov (United States)

    Kaina, B; Lohrer, H; Karin, M; Herrlich, P

    1990-01-01

    Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of reduced glutathione synthesis, the transfectants were not more resistant to the lethal effects of ionizing radiation and bleomycin than the parent cells. Thus free radicals generated by these agents cannot be scavenged efficiently by MT in vivo. The hMT-IIA transfectants, however, but not control transfectants harboring a BPV-MT promoter-neo construct, tolerated significantly higher doses of the alkylating agents N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Resistance and MT overexpression occurred irrespective of selection and cultivation in cadmium and zinc. There was no increase in resistance to methyl methanesulfonate and N-hydroxyethyl-N-chloroethylnitrosourea. MT did not affect the degree of overall DNA methylation after N-methyl-N-nitrosourea treatment nor the level of O6-methylguanine-DNA methyltransferase. The results suggest that MT participates as a cofactor or regulatory element in repair or tolerance of toxic alkylation lesions. Images PMID:2320583

  1. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    KAUST Repository

    Hefzi, Hooman

    2016-11-23

    Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways in CHO and associated them with >1,700 genes in the Cricetulus griseus genome. The genome-scale metabolic model based on this reconstruction, iCHO1766, and cell-line-specific models for CHO-K1, CHO-S, and CHO-DG44 cells provide the biochemical basis of growth and recombinant protein production. The models accurately predict growth phenotypes and known auxotrophies in CHO cells. With the models, we quantify the protein synthesis capacity of CHO cells and demonstrate that common bioprocess treatments, such as histone deacetylase inhibitors, inefficiently increase product yield. However, our simulations show that the metabolic resources in CHO are more than three times more efficiently utilized for growth or recombinant protein synthesis following targeted efforts to engineer the CHO secretory pathway. This model will further accelerate CHO cell engineering and help optimize bioprocesses.

  2. Flow cytometric studies of the survival of cytochalasin-induced polyploidy in Chinese hamster ovary cells.

    Science.gov (United States)

    Court, J B; Burn, C; Moore, J L

    1990-05-01

    A method has been developed to estimate the post-irradiation survival of cytochalasin B-induced polyploidization of adherent Chinese hamster ovary cell using the flow cytometer. After exposure to radiation, surviving cells are allowed to become polyploid in the presence of cytochalasin, and are detached using trypsin, fixed by the addition of glutaraldehyde and stained using mithramycin. DNA content distributions are polymodal, and the absolute number of cells per culture in any given ploidy class is estimated by reference to a non-fluorescent bead internal standard, detected using forward scatter. Post-irradiation survival is defined as the ability to reach a given DNA content, and is reduced exponentially with dose. A bioassay to determine optimum cytochalasin concentrations can be derived from the relative size of the 2C (G0/G1) peak in the DNA content distribution. At culture densities greater than about 8 x 10(4) cell/cm2 the relative number of cells reaching at least 16C is reduced, but this inhibition is partially reversible by an increase in the medium glucose concentration, but not by the use of cytochalasin D or dihydro B.

  3. Normal DNA ligase activity in a γ-ray-sensitive Chinese hamster mutant

    International Nuclear Information System (INIS)

    Stamato, T.D.; Hu, J.

    1987-01-01

    A Chinese hamster cell mutant (XR-1) was previously described that is extremely deficient in the repair of double-strand DNA breaks produced by γ-irradiation during the sensitive G 1 -early-S period and somewhat deficient in repair of γ-ray-induced single-strand DNA breaks. To determine whether a deficiency in DNA ligase activity might underlie the biochemical defect, protein extracts from mutant and parental cells were examined for their ability to ligate single- and double-strand breaks in DNA. The kinetics of ligation of single 5'-phosphate-3'-hydroxyl breaks in double-stranded DNA were the same in protein extracts from both cells. After separation of protein extracts by gel-filtration chromatography, the percentage of activity in the large and small molecular forms of DNA ligase was also similar in the two cells. Finally, protein extracts prepared from exponentially growing or G 1 -synchronized mutant and parental cells were equal in their ability to ligate blunt-end DNA substrates. These data suggest that a deficiency in DNA ligase is not the cause of the repair defect in the XR-1 mutant cell. (Auth.)

  4. Ferritin-iron increases killing of Chinese hamster ovary cells by X-irradiation

    International Nuclear Information System (INIS)

    Nelson, J.M.; Stevens, R.G.

    1992-01-01

    Stationary-phase Chinese hamster ovary cells were cultured in medium containing ferritin (∼19% iron by weight) added at concentrations ranging from 0 to 128 μg/ml. One set of cultures was unirradiated, another set exposed to 4.0 Gy of X-ray. Clonogenic cell survival was assessed in each set of cultures. In the absence of added ferritin, 4.0 Gy killed approximately 50% of the cells. In the absence of radiation, ferritin was not toxic at less than 48 μg/ml; above 48 μg/ml, toxicity increased with concentration. Apoferritin was not toxic at any concentration tested (up to 1000 μg/ml). Although 32 μg/ml ferritin, reflecting only a 3-6 fold increase in iron concentration over normal serum, was not toxic, it reduced survival of X-irradiated cells by an additional 75%. These results indicate that a sublethal concentration of ferritin can be a potent radiosensitizer. (Author)

  5. DNA conformation of Chinese hamster V79 cells and sensitivity to ionizing radiation

    International Nuclear Information System (INIS)

    Olive, P.L.; Hilton, J.; Durand, R.E.

    1986-01-01

    Chinese hamster V79 cells grown for 20 h in suspension culture form small clusters of cells (spheroids) which are more resistant to killing by ionizing radiation than V79 cells grown as monolayers. This resistance appears to be due to the greater capacity of cells grown in contact to repair radiation damage. Attempts to relate this ''contact effect'' to differences in DNA susceptibility or DNA repair capacity have provided conflicting results. Two techniques, alkaline sucrose gradient sedimentation and alkaline elution, show no difference in the amounts of radiation-induced DNA single-strand breakage or its repair between suspension or monolayer cells. However, using the alkali-unwinding assay, the rate of DNA unwinding is much slower for suspension cells than for monolayer cells. Interestingly, a decrease in salt concentration or in pH of the unwinding solution eliminates these differences in DNA unwinding kinetics. A fourth assay, sedimentation of nucleoids on neutral sucrose gradients, also shows a significant decrease in radiation damage produced in suspension compared to monolayer cultures. It is believed that this assay measures differences in DNA conformation (supercoiling) as well as differences in DNA strand breakage. We conclude from these four assays that the same number of DNA strand breaks/Gy is produced in monolayer and spheroid cells. However, changes in DNA conformation or packaging occur when cells are grown as spheroids, and these changes are responsible for reducing DNA damage by ionizing radiation

  6. Potassium ion influx measurements on cultured Chinese hamster cells exposed to 60-hertz electromagnetic fields

    International Nuclear Information System (INIS)

    Stevenson, A.P.; Tobey, R.A.

    1985-01-01

    Potassium ion influx was measured by monitoring 42 KCl uptake by Chinese hamster ovary (CHO) cells grown in suspension culture and exposed in the culture medium to 60-Hz electromagnetic fields up to 2.85 V/m. In the presence of the field CHO cells exhibited two components of uptake, the same as previously observed for those grown under normal conditions; both these components of influx were decreased when compared to sham-exposed cells. Although decreases were consistently observed in exposed cells when plotted as loge of uptake, the differences between the means of the calculated fluxes of exposed and sham-exposed cells were quite small (on the order of 4-7%). When standard deviations were calculated, there was no significant difference between these means; however, when time-paired uptake data were analyzed, the differences were found to be statistically significant. Cells exposed only to the magnetic field exhibited similar small decreases in influx rates when compared to sham-exposed cells, suggesting that the reduction in K+ uptake could be attributed to the magnetic field. Additionally, intracellular K+ levels were measured over a prolonged exposure period (96 h), and no apparent differences in intracellular K+ levels were observed between field-exposed and sham-exposed cultures. These results indicate that high-strength electric fields have a small effect on the rate of transport of potassium ions but no effect on long-term maintenance of intracellular K+

  7. Effect of dihydroxyanthraquinone (DHAQ) and radiation on the survival of cultured Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Kimler, B.F.

    1983-01-01

    Dihydroxyanthraquinone (DHAQ) is currently being tested as a cancer chemotherapeutic agent because of its structural similarity to Adriamycin (ADR) and other DNA-intercalating antibiotics. The interaction of DHAQ and ionizing radiation on the induction of cell lethality was investigated in Chinese hamster ovary cells in culture. In asynchronous populations of cells, DHAQ produced a slight enhancement of radiation-induced cell lethality as evidenced by changes in both shoulder and slope of the radiation dose-survival curves. However, DHAQ had no effect on either the extent or time course of recovery from sublethal radiation damage. In synchronous populations of cells treated at various times before or after selection in mitosis, the combination of DHAQ and radiation produced greater cell killing than that predicted based on simple additivity of effect, with a decided enhancement for cells treated during S phase. These results indicate that DHAQ is similar to other DNA-intercalating antibiotics in regard to the interaction with ionizing radiation to produce cell lethality

  8. Interactive cytotoxicity of etoposide and radiation on cultured Chinese hamster V-79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Shimada, Yuji; Kamata, Rikisaburo

    1989-01-01

    Etoposide is a semisynthetic derivative of podophyllotoxin and is an active antitumor agent. The interactive cytotoxic effect of Etoposide and radiation was investigated using cultured Chinese hamster V-79 cells. The surviving fraction of the cells was reduced by only 20%, when the cells were exposed to 5μg/ml of Etoposide for 30 min. Etoposide at this concentration reduced the width of the shoulder of the radiation survival curve. The change became more significant with increase in the concentration of Etoposide. The Dqs (quasithreshold doses) of the radiation survival curves were 5.39, 3.28, 2.13 and 0.54Gy, although the Dos (37% dose slopes) of the radiation survival curves were 2.55, 2.49, 2.39 and 2.18 Gy, when combination treatment with radiaiton and 0, 5, 10 and 20 μg/ml of Etoposide, respectively, was carried out. The cytotoxic effect became increased when fractional treatments with Etoposide and radiation were performed. The results obtained suggest that the mechanism of the interactive cytotoxic effect of this combination treatment involves a reciprocal action of Etoposide and sublethal damage by the radiation to the cells. (author)

  9. Effect of pepleomycin combined with irradiation on cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu

    1983-01-01

    The combined effect of pepleomycin (PEP), a bleomycin derivative, with irradiation was investigated on cultured Chinese hamster V79 cells. An additive effect was observed when PEP and irradiation were given simultaneously. A time interval between PEP (50μg/ml for one hour) and subsequent irradiation (10 Gy) increased the survival, and it became maximum when the time interval exceeded 2 hours. PEP-induced potentially lethal damage (PLD) was recovered when trysinization was delayed, and this recovery increased the survival. When PEP was given at a time interval after initial irradiation, the survival was decreased to below that following simultaneous treatment of the two modalities, and it became minimum when the time interval was 5 to 6 hours. Cells in ''G 2 -block'' induced by 10 Gy irradiation were partially synchronized, and cells in G 2 -M phase were more sensitive to PEP than those in S phase. It was considered that cells became more sensitive to PEP when they were irradiated 5 to 6 hours previously. However, cells recovery at any cell age when trypsinization was delayed. The benefit of a time interval between the two modalities was decreased by this recovery. (author)

  10. Resistance to DNA denaturation in irradiated Chinese hamster V79 fibroblasts is linked to cell shape

    International Nuclear Information System (INIS)

    Olive, P.L.; Vanderbyl, S.; MacPhail, S.H.

    1991-01-01

    Exponentially growing Chinese hamster V79-171b lung fibroblasts seeded at high density on plastic (approximately 7 x 10(3) cells/cm2) flatten, elongate, and produce significant amounts of extracellular fibronectin. When lysed in weak alkali/high salt, the rate of DNA denaturation following exposure to ionizing radiation is exponential. Conversely, cells plated at low density (approximately 7 x 10(2) cells/cm2) on plastic are more rounded 24 h later, produce little extracellular fibronectin, and display unusual DNA denaturation kinetics after X-irradiation. DNA in these cells resists denaturation, as though constraints to DNA unwinding have developed. Cell doubling time and distribution of cells in the growth cycle are identical for both high and low density cultures as is cell survival in response to radiation damage. The connection between DNA conformation and cell shape was examined further in low density cultures grown in conditioned medium. Under these conditions, cells at low density were able to elongate, and DNA denaturation of low density cultures was identical to that of high density cultures. Conversely, cytochalasin D, which interferes with actin polymerization causing cells to round up and release fibronectin, allowed development of constraints in high density cultures. These results suggest that DNA conformation is sensitive to changes in cell shape which result when cells are grown in different environments. However, these changes in DNA conformation detected by the DNA unwinding assay do not appear to play a direct role in radiation-induced cell killing

  11. Laser microirradiation of Chinese hamster cells at wavelength 365 nm: effects of psoralen and caffeine

    International Nuclear Information System (INIS)

    Cremer, T.; Peterson, S.P.; Cremer, C.; Berns, M.W.

    1981-01-01

    Cells of a V79 subline of the Chinese hamster were microirradiated at wavelength 365 nm in the presence of the psoralen derivative, trioxsalen. Microirradiation was accomplished by a pulsed argon laser microbeam either in anaphase or in interphase 3 h after mitosis. Inhibition of clonal growth and formation of micronuclei at the first postirradiation mitosis were observed after microirradiation of anaphase chromosomes and of small parts of the interphase nucleus. Microirradiation of the cytoplasm beside the interphase nucleus or between the sets of chromosomes moving apart from each other in anaphase did not produce these effects. Anaphase experiments showed that only the daughter cell which received microirradiated chromatin exhibited an abnormal growth pattern. Most interestingly, shattering of the whole chromosome complement could be induced by microirradiation of small parts of the interphase nucleus and post-treatment with caffeine. Since microirradiation of chromatin in the absence of psoralen was not effective, we consider formation of psoralen photoadducts to nucleic acids in microirradiated chromatin to be the specific cause of the effects. We suggest that DNA photolesions in chromosome segments present in the microirradiated part of the nucleus can induce shattering of all the chromosomes in the microirradiated nucleus. Several possibilities are discussed to explain this unexpected finding

  12. Effect of anolyte on growth and division of Chinese hamster cancerous cells

    Directory of Open Access Journals (Sweden)

    saeed Mohammadzadeh

    2009-04-01

    Full Text Available Background: At present, cancer can be controlled by chemotherapy, but unfortunately, this method has strong side effects and scientist try to reduce them using different substances. 2 kinds of activated water called anolyte and catholyte have electrochemical property and antibacterial and oxidative properties respectively. The aim of this research is to study the effect of anolyte on growth and division of cancerous cells. Materials and Methods: In this research, different concentration of anolyte, 1 . 7, 2, 5,8.3 and 10 percent of anolyte and control with 2 and 5 percent of serum physiologic were added on converted cell of Chinese hamster (line b11dii-FAF28 clone 237 in 12 plastic and 15 glass flasks. After adding, converted cell was counted with the help of hoemocytometer and microscope. Data of experiment analyzed and results compared by t test, as well as using Excell software their diagrams were drawn. Results: The results indicated that anolyte had significant effect on cancer cells. In concentration of 1.7% cell division was decreased but in concentration of 8.3 %, division of cancerous cells was blocked and cells were fixed. Conclusion: Considering the low amount of sodium chloride in anolyte, it seems that, this solution (Anolyte hasn’t side effects and advers effect on the cells body.

  13. Hypermutability of a UV-sensitive aphidicolin-resistant mutant of Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Liu, P.K.; Chang, C.; Trosko, J.E.

    1982-01-01

    An ultraviolet light (UV)-sensitive thymidine auxotroph of Chinese hamster V79 cells that exhibits pleiotropic effects such as a high level of deoxycytidine triphosphate, slow growth, sensitivity to cytidine, and high frequencies of site-specific bromodeoxyuridine-dependent chromosomal aberrations was selected by its resistance to aphidicolin. The UV-induced mutability of this mutant and one of its revertants, which retains some of the phenotypes listed above, was studied in 3 mutation assay systems. The results showed that the mutant was hypermutable for ouabain and diphtheria-toxin-resistant mutations compared to wild-type V79 cells at the same UV dose or the same survival level. The mutant exhibits a delayed expression of maximal frequency of induced 6-thioguanine-resistant mutants. When maximal frequencies are compared at the same UV dose, the mutant also has higher mutation frequencies at the hypoxanthine-guanine phosphoribosyl transferase locus. The revertant was similar to the wild-type in UV sensitivity and mutability. (orig./AJ)

  14. Influence of 239Pu aerosol production temperature on biological responses in Chinese hamsters

    International Nuclear Information System (INIS)

    Brooks, A. L.; Peters, R.F.; Mewhinney, J.A.

    1977-01-01

    Studies on the retention, distribution and effects of inhaled 239 Pu particles produced at different temperatures are continuing in an effort to assess the consequences of accidental inhalation exposures under various conditions. Three groups of Chinese hamsters, 381 animals per group, were exposed to aerosols of 239 Pu which had been treated in a heating column at either 50, 600 or 1150 0 C. Retention and distribution of the plutonium through 600 days after exposure reflected the relative insolubility of the aerosols heated at 1150 and 600 0 C, and the relative solubility of the aerosol heated at 50 0 C. Animals exposed to either of the insoluble aerosols had 80 to 90 percent of the sacrifice body burden in the lung at 400 days after exposure whereas animals exposed to the aerosol heated at 50 0 C had only 10 percent of the sacrifice body burden in the lung at 400 days. Translocation was mainly to the liver. To date, survival of the animals seemed to depend primarily on activity level, with production temperature exerting an influence only at the highest activities

  15. 12-O-Tetradecanoyl-phorbol-13-acetate and its relationship to SCE induction in Syrian and Chinese hamster cells

    International Nuclear Information System (INIS)

    Popescu, N.C.; Amsbaugh, S.C.; Larramendy, M.L.; DiPaolo

    1982-01-01

    12-O-Tetradecanoyl-phorbol-13-acetate (TPA) in conditions that produce enhancement of ultraviolet light (UV) and x-irradiation Syrian hamster embryo cell (HEC) transformation did not cause further increase in the sister chromatid exchange (SCE) frequency induced by UV and x-irradiation, two physical carcinogens that differ in their mode of DNA interaction and efficiency of SCE induction. Several factors which might influence SCE induction by TPA were studied on HEC and Chinese hamster V79-4 cells. Heat-inactivated serum was used because of the possibility that a serum component may interfere with TPA ability to cause SCE. TPA effect on SCE was determined at the first and second division post treatment on cells exposed to different 5-bromodeoxyuridine (BrdUrd) concentrations. Independent of BrdUrd concentration (1-10μg/ml medium) and the number of cells divisions post treatment, TPA (0.01-2μg/ml medium) was ineffective in inducing SCE in exponentially and stationary HEC cultures cultivated in medium supplemented with heat-inactivated serum. Also, TPA did not increase the SCE frequency in V79-4 Chinese hamster cells cultured in heat-activated or noninactivated serum. Although SCE induction, a cellular response to carcinogen-induced DNA damage, may be important for the induction of transformation by environmental agents, the enhancement of transformation frequency caused by TPA occurs without further DNA alterations involved in SCE formation

  16. Phosphorylation of 3-deazaguanosine by nicotinamide riboside kinase in Chinese hamster ovary cells.

    Science.gov (United States)

    Saunders, P P; Tan, M T; Spindler, C D; Robins, R K

    1989-12-01

    The growth inhibitory activity of 3-deazaguanosine toward a mutant line (TGR-3) of Chinese hamster ovary cells deficient in hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) was substantially reversed by the simultaneous addition of nicotinamide riboside. The activities of most other ribonucleoside analogues tested were unaffected. The formation of cellular 3-deazaGMP and 3-deazaGTP from the ribonucleoside analogue, as measured by high-pressure liquid chromatography, was inhibited by the presence of nicotinamide riboside. The inhibition was dependent on concentration of 3-deazaguanosine and could also be demonstrated by following the metabolism of 3-deazaguanosine, labeled with 14C in the ribose moiety, to [14C]3-deazaGTP. In the presence of 100 microM nicotinamide riboside formation of the labeled triphosphate derivative of 3-deazaguanosine was undetectable. A 3-deazaguanosine phosphorylating activity was separated from other cellular kinases by DEAE-cellulose chromatography. Contaminating purine nucleoside phosphorylase (EC 2.4.2.1) was subsequently removed by sucrose density gradient centrifugation. The resulting enzyme preparation demonstrated the greatest activities with nicotinamide riboside and 3-deazaguanosine and, in addition, could also phosphorylate tiazofurin and guanosine to lesser, but significant, degrees. These and other observations suggest that 3-deazaguanosine, and perhaps other agents such as tiazofurin, may, at least in part, be phosphorylated by a nicotinamide ribonucleoside kinase in these cells. If so, it is possible that the activity of this agent in other types of cells in vivo could be dependent upon the presence of this enzyme and that it could be influenced by cellular concentrations of the natural pyridine nucleoside.

  17. Phosphatidylserine biosynthesis in cultured Chinese hamster ovary cells. II. Isolation and characterization of phosphatidylserine auxotrophs

    International Nuclear Information System (INIS)

    Kuge, O.; Nishijima, M.; Akamatsu, Y.

    1986-01-01

    Chinese hamster ovary (CHO) cell mutants that required exogenously added phosphatidylserine for cell growth were isolated by using the replica technique with polyester cloth, and three such mutants were characterized. Labeling experiments on intact cells with 32 Pi and L-[U- 14 C]serine revealed that a phosphatidylserine auxotroph, designated as PSA-3, was strikingly defective in phosphatidylserine biosynthesis. When cells were grown for 2 days without phosphatidylserine, the phosphatidylserine content of PSA-3 was about one-third of that of the parent. In extracts of the mutant, the enzymatic activity of the base-exchange reaction of phospholipids with serine producing phosphatidylserine was reduced to 33% of that in the parent; in addition, the activities of base-exchange reactions of phospholipids with choline and ethanolamine in the mutant were also reduced to 1 and 45% of those in the parent, respectively. Furthermore, it was demonstrated that the serine-exchange activity in the parent was inhibited approximately 60% when choline was added to the reaction mixture whereas that in the mutant was not significantly affected. From the results presented here, we conclude the following. There are at least two kinds of serine-exchange enzymes in CHO cells; one (serine-exchange enzyme I) can catalyze the base-exchange reactions of phospholipids with serine, choline, and ethanolamine while the other (serine-exchange enzyme II) does not use the choline as a substrate. Serine-exchange enzyme I, in which mutant PSA-3 is defective, plays a major role in phosphatidylserine biosynthesis in CHO cells. Serine-exchange enzyme I is essential for the growth of CHO cells

  18. Isolation and characterization of a Chinese hamster ovary cell mutant with altered regulation of phosphatidylserine biosynthesis

    International Nuclear Information System (INIS)

    Hasegawa, K.; Kuge, O.; Nishijima, M.; Akamatsu, Y.

    1989-01-01

    We have screened approximately 10,000 colonies of Chinese hamster ovary (CHO) cells immobilized on polyester cloth for mutants defective in [14C]ethanolamine incorporation into trichloroacetic acid-precipitable phospholipids. In mutant 29, discovered in this way, the activities of enzymes involved in the CDP-ethanolamine pathway were normal; however, the intracellular pool of phosphorylethanolamine was elevated, being more than 10-fold that in the parental CHO-K1 cells. These results suggested that the reduced incorporation of [14C]ethanolamine into phosphatidylethanolamine in mutant 29 was due to dilution of phosphoryl-[14C]ethanolamine with the increased amount of cellular phosphorylethanolamine. Interestingly, the rate of incorporation of serine into phosphatidylserine and the content of phosphatidylserine in mutant 29 cells were increased 3-fold and 1.5-fold, respectively, compared with the parent cells. The overproduction of phosphorylethanolamine in mutant 29 cells was ascribed to the elevated level of phosphatidylserine biosynthesis, because ethanolamine is produced as a reaction product on the conversion of phosphatidylethanolamine to phosphatidylserine, which is catalyzed by phospholipid-serine base-exchange enzymes. Using both intact cells and the particulate fraction of a cell extract, phosphatidylserine biosynthesis in CHO-K1 cells was shown to be inhibited by phosphatidylserine itself, whereas that in mutant 29 cells was greatly resistant to the inhibition, compared with the parental cells. As a conclusion, it may be assumed that mutant 29 cells have a lesion in the regulation of phosphatidylserine biosynthesis by serine-exchange enzyme activity, which results in the overproduction of phosphatidylserine and phosphorylethanolamine as well

  19. Mutations in alpha- and beta-tubulin affect spindle formation in Chinese hamster ovary cells.

    Science.gov (United States)

    Abraham, I; Marcus, M; Cabral, F; Gottesman, M M

    1983-10-01

    Two Chinese hamster ovary cell lines with mutated beta-tubulins (Grs-2 and Cmd-4) and one that has a mutation in alpha-tubulin (Tax-1) are temperature sensitive for growth at 40.5 degrees C. To determine the functional defect in these mutant cells at the nonpermissive temperature, they were characterized with respect to cell cycle parameters and microtubule organization and function after relatively short periods at 40.5 degrees C. At the nonpermissive temperature all the mutants had normal appearing cytoplasmic microtubules. Premature chromosome condensation analysis failed to show any discrete step in the interphase cell cycle in which these mutants are arrested. These cells, however, show several defects at the nonpermissive temperature that appear related to the function of microtubules during mitosis. Time-lapse studies showed that mitosis was lengthened in the three mutant lines at 40.5 degrees C as compared with the wild-type cells at this temperature, resulting in a higher proportion of cells in mitosis after temperature shift. There was also a large increase in multinucleated cells in mutant populations after incubation at the nonpermissive temperature. Immunofluorescent studies using a monoclonal anti--alpha-tubulin antibody showed that the mutant cells had a high proportion of abnormal spindles at the nonpermissive temperature. The two altered beta-tubulins and the altered alpha-tubulin all were found to cause a similar phenotype at the high temperature that results in mitotic delay, defective cytokinesis, multinucleation, and ultimately, cell death. We conclude that spindle formation is the limiting microtubule function in these mutant cell lines at the nonpermissive temperature and that these cell lines will be of value for the study of the precise role of tubulin in mammalian spindle formation.

  20. Hyperthermic radiosensitization of synchronous Chinese hamster cells: relationship between lethality and chromosomal aberrations

    International Nuclear Information System (INIS)

    Dewey, W.C.; Sapareto, S.A.; Betten, D.A.

    1978-01-01

    Synchronous Chinese hamster cells in vitro were obtained by mitotic selection. The cells were heated at 45.5 0 C for 4 min in mitosis, 11 min in G 1 , or 7 min in S sphase and then x-irradiated immediately thereafter. Colony survival from heat alone was 0.30 to 0.45, and the frequency of chromosomal aberrations induced by heat was 0.00, 0.14, or 0.97 for heat treatments during M, G 1 , or S, respectively. As shown previously, lethality from hyperthermia alone is due to chromosomal aberrations only when the cells are heated during S phase. The log survival (D 0 /sup approximately/ = 80 rad) and aberration frequency curves for cells irradiated during mitosis were linear, and the only effect of hyperthermia was to shift the curves in accord with the effect from heat alone. Thus, hyperthermia did not radiosensitize the mitotic cells. The cells irradiated in G 1 were more resistant (D 0 /sup approximately/ = 100 rad) than those irradiated in mitosis, and the survival and aberration frequency curves both had shoulders. The primary effect of hyperthermia was to greatly reduce the shoulders of the curves and to increase the slopes by about 23%. The cells irradiated in S were the most resistant (D 0 /sup approximately/ = 140 rad), and the survival and aberration frequency curves both had large shoulders. For both end points of lethality and chromosomal aberrations, heat selectively radiosensitized S-phase cells relative to G 1 cells by removing most of the shoulder and increasing the slope by about 45%. For cells treated in G 1 or S, the increase in radiosensitization following hyperthermia can be accounted for by an increase in the frequency of chromosomal aberrations

  1. Additive action of ionizing and non-ionizing radiations throughout the Chinese hamster cell-cycle

    International Nuclear Information System (INIS)

    Han, A.; Elkind, M.M.

    1977-01-01

    X-rays and γ-rays produce lesions in nuclear DNA which are qualitatively different from those produced by UV-light. Studies have been made of the effects of X-rays and UV light on the survival of synchronous cultures of Chinese hamster V79 cells. There were qualitative differences in the age-response patterns for survival after single doses of the two types of radiation, but combined UV-and X-irradiation produced enhanced lethality at all ages throughout the cell cycle. The minimum survival from the combined irradiation was at the middle of the S period, and the survival curves at this stage of the cell cycle were further investigated. Exposure to UV immediately before graded X-ray doses removed the shoulder on the X-ray survival curve in a progressive manner, while the D 0 value increased only slightly. The results correspond to complete additivity of X-ray damage to UV damage. Exposure to X-rays immediately before graded UV doses indicated that only part of the damage produced by the X-rays could be added to the UV-damage. Even after X-ray doses which reduced survival to levels which surpassed the shoulder of the UV-only survival curve, the shoulder persisted on the combined treatment survival curves. Measurements were made of the time-course of the change in molecular weight of single-stranded DNA after X-irradiation preceded by UV-irradiation. Only a small amount of slowing of repair of X-ray induced lesions was detected after a large UV dose. Possible mechanisms for the interactions between the two types of damage are discussed. (U.K.)

  2. Diversity in host clone performance within a Chinese hamster ovary cell line.

    Science.gov (United States)

    O'Callaghan, Peter M; Berthelot, Maud E; Young, Robert J; Graham, James W A; Racher, Andrew J; Aldana, Dulce

    2015-01-01

    Much effort has been expended to improve the capabilities of individual Chinese hamster ovary (CHO) host cell lines to synthesize recombinant therapeutic proteins (rPs). However, given the increasing variety in rP molecular types and formats it may be advantageous to employ a toolbox of CHO host cell lines in biomanufacturing. Such a toolbox would contain a panel of hosts with specific capabilities to synthesize certain molecular types at high volumetric concentrations and with the correct product quality (PQ). In this work, we examine a panel of clonally derived host cell lines isolated from CHOK1SV for the ability to manufacture two model proteins, an IgG4 monoclonal antibody (Mab) and an Fc-fusion protein (etanercept). We show that these host cell lines vary in their relative ability to synthesize these proteins in transient and stable pool production format. Furthermore, we examined the PQ attributes of the stable pool-produced Mab and etanercept (by N-glycan ultra performance liquid chromatography (UPLC) and liquid chromatography - tandem mass spectrometry (LC-MS/MS), respectively), and uncovered substantial variation between the host cell lines in Mab N-glycan micro-heterogeneity and etanercept N and O-linked macro-heterogeneity. To further investigate the capabilities of these hosts to act as cell factories, we examined the glycosylation pathway gene expression profiles as well as the levels of endoplasmic reticulum (ER) and mitochondria in the untransfected hosts. We uncovered a moderate correlation between ER mass and the volumetric product concentration in transient and stable pool Mab production. This work demonstrates the utility of leveraging diversity within the CHOK1SV pool to identify new host cell lines with different performance characteristics. © 2015 American Institute of Chemical Engineers.

  3. Mutation and repair in an ultraviolet-sensitive Chinese hamster ovary cell line

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.D.

    1981-01-01

    An ultraviolet (UV) light-sensitive mutant of Chinese hamster ovary cells (CHO) has been isolated and characterized with respect to a number of post-irradiation responses. The UV-sensitive mutant, termed 43-3B, was isolated by replica plating of mutagenized CHO cells, followed by a challenge with UV radiation. 43-3B has the same growth rate and chromosome number as the wild-type CHO-9. 43-3B is hypersensitive to the lethal effects of UV light (D/sub 0/ of 0.3 J/m/sup 2/ as compared to 3.2 J/m/sup 2/ for the wild-type). A marked UV-hypermutability is observed in 43-3B as compared to the wild-type. The UV-sensitive mutant is also sensitive to killing by simulated solar light, although the D/sub 0/ ratio is not as great as for germicidal UV. A much reduced ability of recover control rates of semiconservative DNA synthesis after UV irradiation was observed in the repair-deficient 43-3B cell line, suggesting that the removal of UV-induced replication blocks by excision repair is the most important factor in allowing recovery of UV-inhibited DNA synthesis. Recovery of colony-forming ability between fractionated UV exposures was observed in the wild-type CHO-9, but little recovery was seen in 43-3B. This indicates that excision repair capability can also be important in split-fluence recovery.

  4. Isolation and characterization of a Chinese hamster ovary cell mutant with altered regulation of phosphatidylserine biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, K.; Kuge, O.; Nishijima, M.; Akamatsu, Y. (National Institute of Health, Tokyo (Japan))

    1989-11-25

    We have screened approximately 10,000 colonies of Chinese hamster ovary (CHO) cells immobilized on polyester cloth for mutants defective in (14C)ethanolamine incorporation into trichloroacetic acid-precipitable phospholipids. In mutant 29, discovered in this way, the activities of enzymes involved in the CDP-ethanolamine pathway were normal; however, the intracellular pool of phosphorylethanolamine was elevated, being more than 10-fold that in the parental CHO-K1 cells. These results suggested that the reduced incorporation of (14C)ethanolamine into phosphatidylethanolamine in mutant 29 was due to dilution of phosphoryl-(14C)ethanolamine with the increased amount of cellular phosphorylethanolamine. Interestingly, the rate of incorporation of serine into phosphatidylserine and the content of phosphatidylserine in mutant 29 cells were increased 3-fold and 1.5-fold, respectively, compared with the parent cells. The overproduction of phosphorylethanolamine in mutant 29 cells was ascribed to the elevated level of phosphatidylserine biosynthesis, because ethanolamine is produced as a reaction product on the conversion of phosphatidylethanolamine to phosphatidylserine, which is catalyzed by phospholipid-serine base-exchange enzymes. Using both intact cells and the particulate fraction of a cell extract, phosphatidylserine biosynthesis in CHO-K1 cells was shown to be inhibited by phosphatidylserine itself, whereas that in mutant 29 cells was greatly resistant to the inhibition, compared with the parental cells. As a conclusion, it may be assumed that mutant 29 cells have a lesion in the regulation of phosphatidylserine biosynthesis by serine-exchange enzyme activity, which results in the overproduction of phosphatidylserine and phosphorylethanolamine as well.

  5. DNA strand break induction and rejoining in Chinese hamster cells as a function of radiation quality

    International Nuclear Information System (INIS)

    Ritter, M.A.

    1976-01-01

    Chinese Hamster cells (V79-S171) were irradiated with 300 kVp x-rays and low-energy charged particles, covering an LET range of about 1 to 2900 keV/μm. The LET dependence of DNA strand-break induction and the rejoining kinetics of these breaks during post-irradiation incubation were investigated using alkaline sucrose gradients. The break-induction studies indicated that strand-break efficiency generally decreases with increasing LET, that low-energy, heavy ions induce DNA breaks non-randomly, and that anoxia protects less against high-LET induction than against low-LET induction of DNA breaks. Strand-break rejoining studies indicate the presence of three classes of breaks: a fast-rejoining class (T 1 / 2 = 8 min), whose induction efficiency decreases rapidly with LET increase; a slow-rejoining class (T 1 / 2 appoximately equal to 90 min), whose induction efficiency decreased gradually with LET increase; and a non-rejoining class (remained open during post-irradiation incubation), whose induction efficiency demonstrated a peaked response as a function of LET. The RBE for induction of non-rejoining DNA breaks rose to a maximum of 4.9 at an LET of 150 keV/μm and then decreased with further LET increase. This peaked response agrees closely with RBE's from the literature that are based upon initial slopes of mammalian cell survival curves as a function of LET. The agreement implies that non-rejoining DNA breaks are causally related to the lethal, irreversible component of cell inactivation by radiation

  6. Influence of irradiation at different stages of mitotic cycle upon production of sister chromatid exchanges in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Antoshina, M.M.; Poryadkova, N.A.; Luchnik, N.V.

    1982-01-01

    Frequency of sister chromatid exchanges (SCE) and microexchanges in Chinese hamster cells has been studied by means of the method of differential staining of chromatids on irradiation at different stages of the mitotic cycle. It is shown that the irradiation enhances frequency of SCE and microexchanges if it is carried out before the end of DNA replication synthesis. Comparison of frequency depenedence of radiation-induced microexchanges and SCE at different stages of the mitotic cycle results in the conclusion that the microexchanges are none other than small SCE

  7. Comparative study on fast neutrons radiobiological effect on Chinese hamster cells in culture depending on regime of irradiation

    International Nuclear Information System (INIS)

    Elisova, T.V.; Feoktistova, T.P.; Stavrakova, N.M.

    1988-01-01

    Comparative study of regularities of fast neutron radiobiological effect on Chinese hamster cells in culture under pulse and statistic irradiation regimes that was estimated by reproductive death of cells and induced frequency of resistence mutations to 6-tioguanine is carried out. It is stated that with the dose rate increase approximately by 6 orders radiobiological efficiency of fast neutrons decreases. It is suggested that one of the causes of decreasing pulse irradiation efficiency are processes on radiation-chemical level. 9 refs.; 3 figs

  8. Anomalous dose-response characteristics induced by caffeine in ultraviolet-irradiated V79-79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Schroy, C.B.; Todd, P.

    1979-01-01

    Cultured Chinese hamster cell line V79-79 exhibited an increase in survival with increasing UV fluence after a sharp decrease when exposed to 2.5 mM caffeine for 44 h after far-UV irradiation resulting in an anomalous maximum in the survival curve. No survival maximum was evident when either 0 or 1 mM caffeine is administered under the same conditions. The UV survival curve for 2.5 mM caffeine crossed the corresponding 1 mM curve and apparently became asymptotic to the 0 mM curve as UV fluence was increased. Chinese hamster cell lines V79-753B (related to V79-79 by derivation from the same parental line) and M3-1F3 (unrelated) exhibited only potentiation of post-UV lethality by the same concentration of caffeine and had no caffeine-induced anomalies in their survival curves. Xanthine, used alone or in combination with caffeine, only potentiated a slight amount of lethality and appeared not to be a major causative factor of the anomaly. (author)

  9. Effects of preventing O-glycosylation on the secretion of human chorionic gonadotropin in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Matzuk, M.M.; Krieger, M.; Corless, C.L.; Boime, I.

    1987-01-01

    Human chorionic gonadotropin (hCG) is a member of a family of heterodimeric glycoprotein hormones that have a common α subunit but differ in their hormone-specific β-subunits. The β subunit of hCG (hCGβ) is unique among the β subunits in that it contains four mucin-like O-linked oligosaccharides attached to a carboxyl-terminal extension. To study the effects of O-glycosylation on the secretion and assembly of hCG, expression vectors containing either hCGβ gene alone or together with the hCGα gene were transfected into a mutant Chinese hamster ovary cell line, 1d1D, which exhibits a reversible defect in O-glycosylation. The results reveal that hCGβ can be secreted normally in the absence of its O-linked oligosaccharides. hCGβ devoid of O-linked carbohydrate can also combine efficiently with hCGα and be secreted as an intact dimer. The authors conclude that in Chinese hamster ovary cells, the hCGβ O-linked chains play no role in the assembly and secretion of hCG. The normal and O-linked oligosaccharide-deficient forms of hCG secreted by these cells should prove useful in examining the role of O-linked chains on the biological function of hCG

  10. Understanding Transcriptional Enhancement in Monoclonal Antibody-Producing Chinese Hamster Ovary Cells

    Science.gov (United States)

    Nicoletti, Sarah E.

    With the demand for monoclonal antibody (mAB) therapeutics continually increasing, the need to better understand what makes a high productivity clone has gained substantial interest. Monoclonal antibody producing Chinese hamster ovary (CHO) cells with different productivities were provided by a biopharmaceutical company for investigation. Gene copy numbers, mRNA levels, and mAb productivities were previously determined for two low producing clones and their amplified progeny. These results showed an increase in mRNA copy number in amplified clones, which correlated to the observed increases in specific productivity of these clones. The presence of multiple copies of mRNA per one copy of DNA in the higher productivity clones has been coined as transcriptional enhancement. The methylation status of the CMV promoter as well as transcription factor/promoter interactions were evaluated to determine the cause of transcriptional enhancement. Methylation analysis via bisulfite sequencing revealed no significant difference in overall methylation status of the CMV promoter. These data did, however, reveal the possibility of differential interactions of transcription factors between the high and low productivity cell clones. This finding was further supported by chromatin immunoprecipitations previously performed in the lab, as well as literature studies. Transcription activator-like effector (TALE) binding proteins were constructed and utilized to selectively immunoprecipitate the CMV promoter along with its associated transcription factors in the different CHO cell clones. Cells were transfected with the TALE proteins, harvested and subjected to a ChIP-like procedure. Results obtained from the TALE ChIP demonstrated the lack of binding of the protein to the promoter and the need to redesign the TALE. Overall, results obtained from this study were unable to give a clear indication as to the causes of transcriptional enhancement in the amplified CHO cell clones. Further

  11. DNA replication kinetics in x-irradiated Chinese hamster ovary cells

    Energy Technology Data Exchange (ETDEWEB)

    Gerner, E.W.

    1977-08-01

    The kinetics of semiconservative DNA replication have been studied in both asynchronous and synchronized Chinese hamster ovary cells (CHO) irradiated with x-ray doses up to 3000 rad. Amounts of DNA replicated were determined by isopycnic gradient centrifugation of DNA from cells which were incubated after irradiation in medium containing 5-bromodeoxyuridine (50 ..mu..g/ml) and 5-fluorodeoxyuridine (0.1 ..mu..g/ml). The results confirm that cells irradiated in early G/sub 1/ phase experience a delay in their entry into S phase. This G/sub 1/ block is dose independent in the range from 300 to 3000 rad and is 0.5 to 0.7 hr in length. Cells at the G/sub 1//S boundary are insensitive to x-ray induced perturbations of bulk DNA synthetic rates when exposed to doses less than 1000 rad. At doses in excess of 1000 rad, these cells are inhibited from replicating their DNA for a time, but ultimately replicate near-control levels of their DNA. Cells irradiated in S phase again show no effects of x-ray doses below 1000 rad on their ability to replicate bulk DNA. After a 3000-rad exposure, however, the rate of DNA replication in these S-phase cells is markedly reduced compared to that of controls. Irradiation of asynchronous cells with doses from 150 to 3000 rad does reduce the rate of semiconservative DNA replication in these cultures in a dose-dependent manner. These results confirm that x-ray doses greater than 1000 rad reduce the rate of DNA synthesis in irradiated S-phase cells, thus prolonging the length of S phase. The combined data from asynchronous or synchronized cultures, irradiated with x-ray doses less than 1000 rad, indicate that at least a portion of the reduction in DNA replication rates in irradiated asynchronous CHO cultures is due to the x-ray induced G/sub 1/ block, which reduces the overall number of cells in S phase after irradiation.

  12. Using titer and titer normalized to confluence are complementary strategies for obtaining Chinese hamster ovary cell lines with high volumetric productivity of etanercept

    DEFF Research Database (Denmark)

    Pristovšek, Nuša; Hansen, Henning Gram; Sergeeva, Daria

    2018-01-01

    The selection of clonally-derived Chinese hamster ovary (CHO) cell lines with the highest production rate of recombinant glycoproteins remains a big challenge during early stages of cell line development. Different strategies using either product titer or product titer normalized to cell number...

  13. V-79 Chinese Hamster Cells irradiated with antiprotons, a study of peripheral damage due to medium and long range components of the annihilation radiation

    DEFF Research Database (Denmark)

    Kovacevic, Sandra; Bassler, Niels; Hartley, Oliver

    2009-01-01

    produce a significant background dose and reverse any benefits of higher biological dose in the target area. Materials and methods: Using the Antiproton Decelerator (AD) at CERN (Conseil Europeen pour la Recherche Nucleaire) we irradiated V-79 Chinese Hamster cells embedded in gelatine using an antiproton...

  14. Isolation and structure determination of the intact sialylated N-linked carbohydrate chains of recombinant human follitropin expressed in Chinese hamster ovary cells

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Hård, K.; Mekking, A.; Damm, J.B.L.; Kamerling, J.P.; Boer, W. de; Wijnands, R.A.

    1990-01-01

    Biologically active recombinant human follitropin has been expressed in Chinese hamster ovary cells. The carbohydrate chains of the recombinant glycoprotein hormone were enzymatically released by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F. The oligosaccharides were separated from

  15. Efficient procedure for transferring specific human genes into Chinese hamster cell mutants: interspecific transfer of the human genes encoding leucyl- and asparaginyl-tRNA synthetases

    International Nuclear Information System (INIS)

    Cirullo, R.E.; Dana, S.; Wasmuth, J.J.

    1983-01-01

    A simple and efficient procedure for transferring specific human genes into mutant Chinese hamster ovary cell recipients has been developed that does not rely on using calcium phosphate-precipitated high-molecular-weight DNA. Interspecific cell hybrids between human leukocytes and temperature-sensitive Chinese hamster cell mutants with either a thermolabile leucyl-tRNA synthetase or a thermolabile asparaginyl-tRNA synthetase were used as the starting material in these experiments. These hybrids contain only one or a few human chromosomes and require expression of the appropriate human aminoacyl-tRNA synthetase gene to grow at 39 degrees C. Hybrids were exposed to very high doses of gamma-irradiation to extensively fragment the chromosomes and re-fused immediately to the original temperature-sensitive Chinese hamster mutant, and secondary hybrids were isolated at 39 degrees C. Secondary hybrids, which had retained small fragments of the human genome containing the selected gene, were subjected to another round of irradiation, refusion, and selection at 39 degrees C to reduce the amount of human DNA even further. Using this procedure, Chinese hamster cell lines have been constructed that express the human genes encoding either asparaginyl- or leucyl-tRNA synthetase, yet less than 0.1% of their DNA is derived from the human genome, as quantitated by a sensitive dot-blot nucleic acid hybridization procedure

  16. Effect of secondary radiation from 70 GeV protons and γ-quanta on Chinese hamster chromosomes depending on the cell cycle stage

    International Nuclear Information System (INIS)

    Antipov, A.V.; Aptikaeva, G.F.; Akhmadieva, A.Kh.; Ganassi, E.Eh.; Zaichkina, S.I.; Livanova, I.A.; Smirnova, E.N.

    1987-01-01

    In cultured Chinese hamster cells, no decrease in the number of chromosome aberrations was noted after exposure thereof to 70 GeV protons at the late S-phase as opposed to early one. It is suggested that high biological effectiveness of this type of raiation is associated with its inhibiting effect of cytogenetic damages repair

  17. Accelerated Homology-Directed Targeted Integration of Transgenes in Chinese Hamster Ovary Cells Via CRISPR/Cas9 and Fluorescent Enrichment

    DEFF Research Database (Denmark)

    Lee, Jae Seong; Grav, Lise Marie; Pedersen, Lasse Ebdrup

    2016-01-01

    Targeted gene integration into site-specific loci can be achieved in Chinese hamster ovary (CHO) cells via CRISPR/Cas9 genome editing technology and the homology-directed repair (HDR) pathway. The low efficiency of HDR often requires antibiotic selection, which limits targeted integration...

  18. Mutagenic and epigenetic influence of caffeine on the frequencies of UV-induced ouabain-resistant Chinese hamster cells

    International Nuclear Information System (INIS)

    Chang, Chia-Cheng; Philipps, C.; Trosko, J.E.; Hart, R.W.

    1977-01-01

    Caffeine, given as a post-treatment to UV-irradiated Chinese hamster cells in vitro, modified the frequency of induced mutations at the ouabain resistance locus. Mutation frequencies were increased when caffeine was added only for the DNA repair and mutation fixation period. When caffeine was added after the DNA repair and mutation fixation period, or immediately after DNA damage and for the entire repair and selection period, mutation frequencies were reduced. A hypothesis, given to explain both results, is that caffeine, by blocking a constitutive 'error-free' postreplication repair process, allows an 'error-prone' DNA repair process to produce many mutations. Moreover, caffeine, possibly by modifying C-AMP metabolism, causes a repression of induced mutations which, in effect, explains its anti-mutagenic and anti-carcinogenic properties

  19. Influence of DMSO on Carbon K ultrasoft X-rays induced chromosome aberrations in V79 Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, Adayapalam T., E-mail: natarajan@live.nl [University of Tuscia, Viterbo (Italy); Palitti, Fabrizio [University of Tuscia, Viterbo (Italy); Hill, Mark A. [CRUK/MRC Gray Institute for Radiation Oncology and Biology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom); MRC Radiation and Genome Stability Unit, Harwell, Oxfordshire OX11 0RD (United Kingdom); Stevens, David L. [MRC Radiation and Genome Stability Unit, Harwell, Oxfordshire OX11 0RD (United Kingdom); Ahnstroem, Gunnar [Department of Microbiology and Genetic Toxicology, Stockholm University, Stockholm (Sweden)

    2010-09-10

    Ultrasoft X-rays have been shown to be very efficient in inducing chromosomal aberrations in mammalian cells. The present study was aimed to evaluate the modifying effects of DMSO (a potent scavenger of free radicals) on the frequencies of chromosome aberrations induced by soft X-rays. Confluent held G1 Chinese hamster cells (V79) were irradiated with Carbon K ultrasoft X-rays in the presence and absence of 1 M DMSO and frequencies of chromosome aberrations in the first division cells were determined. DMSO reduced the frequencies of exchange types of aberrations (dicentrics and centric rings) by a factor of 2.1-3.5. The results indicate that free radicals induced by ultrasoft X-rays contribute to a great extent to the induction of chromosome aberrations. The possible implications of these results in interpreting the mechanisms involved in the high efficiency of ultrasoft X-rays in the induction of chromosome aberrations are discussed.

  20. The increase in radioresistance of Chinese hamster cells cultured as spheroids is correlated to changes in nuclear morphology

    International Nuclear Information System (INIS)

    Gordon, D.J.; Milner, A.E.; Beaney, R.P.; Grdina, D.J.; Vaughan, A.T.

    1990-01-01

    Chinese hamster V79 cells grown as spheroids in roller culture are more radioresistant than those grown as monolayers. The supercoiled structure of chromatin, as salt-extracted nucleoids, has been examined using flow cytometry. Irradiated viable cells from spheroid culture contain restraints to supercoil relaxation that are absent in monolayer cells. Further analysis of the chromatin organization from each growth form shows that the radioresistant spheroid cells contain a DNA-protein matrix that is more resistant to detergent-induced degradation. The increase in structural integrity may be due to the retention of a 55-60 kDa protein that is apparent in the nucleoids of spheroid, but not monolayer cells. The increase in structural integrity of the spheroid cells may explain their greater radioresistance by providing a more stable platform for high-fidelity DNA damage repair

  1. The suppressive effect of etoposide on recovery from sublethal radiation damage in Chinese hamster V 79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Shimada, Yuji; Kawamori, Jiro; Kamata, Rikisaburo

    1992-01-01

    The combined effect of radiation and etoposide on the survival of cultured Chinese hamster V 79 cells was investigated. Cells in exponential growth phase were treated with various combinations of radiation and etoposide. The surviving fraction was assessed by colony formation. Etoposide significantly reduced so-called shoulder width, as expressed in Dq (quasithreshold dose), of radiation survival curves. The reduction depended on the increase of etoposide concentrations, although steepening of slopes of exponentially regressing portions of the radiation survival curves was slight. Split dose experiments showed that cells did not recover from sublethal radiation damage in the presence of low concentration of etoposide, although they did recover from sublethal radiation damage under a drug free condition. The results show the suppressive effect of etoposide on recovery from sublethal radiation damage. The effect of a sequential combination of radiation and etoposide was also investigated. The effect was more marked when the interval between radiation and etoposide was shorter regardless of the sequence. (author)

  2. Modification of the repair of potentially lethal damage in plateau-phase Chinese hamster cells by 2-chlorodeoxyadenosine

    International Nuclear Information System (INIS)

    Tanabe, Kiyoshi; Hiraoka, Wakako; Kuwabara, Mikinori; Matsuda, Akira; Ueda, Tohru; Sato, Fumiaki.

    1988-01-01

    The ability of 2-chlorodeoxyadenosine, a ribonucleotide reductase inhibitor, to inhibit the repair of potentially lethal damage was demonstrated in Chinese hamster V79 cells after X irradiation in plateau-phase cultures. This ability of the drug was completely diminished when deoxycytidine was added at the same time, though this was slightly affected by the addition of adenosine, suggesting that this drug was phosphorylated by deoxycytidine kinase to serve as an inhibitor of the repair of potentially lethal damage. Compared with hydroxyurea, another ribonucleotide reductase inhibitor, this drug appeared to contain its own activity which suppressed the repair of potentially lethal damage. A combined study of post-irradiation treatment with hypertonic salt solution and with this drug on the fixation of potentially lethal damage revealed that this drug inhibited the repair of hypertonic-insensitive potentially lethal damage. (author)

  3. Gene mutations, chromosome aberrations and survival after X-ray irradiation of cultured Chinese hamster cells at cysteamine protection

    International Nuclear Information System (INIS)

    Elisova, I.V.; Feoktistova, I.P.

    1983-01-01

    The culture of Chinese hamster cells (clone 431) has been used to study cysteamine action on mutagenous effect of X-rays, determined by the induction of resistance of gene mutations to 6-thioguanine and chromosomal abberations, as well as on the reproductive form of death of irradiated cells. Dose--- effect curves are obtained under conditions of irradiation with and without protector. The factor of dose alteration is 2.0 for chromosomal aberrations and cell survival, and 2.8 for gene mutations. It is sUpposed that cysteamine affects the general mechanisms, which take part in the realis zation of injuries that bring about gene mutations, chromosomal aberrations and cell lethality

  4. Enhancement of excision-repair efficiency by conditioned medium from density-inhibited cultures in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Nakano, S.

    1979-01-01

    Conditioned medium from density-inhibited V79 Chinese hamster cell cultures, given as a post-treatment to UV-irradiated homologous cells, was demonstrated to reduce the lethal action of ultraviolet light by temporarily blocking DNA replication. Since the increased survival was not affected by various nontoxic concentrations of caffeine, such protective effect would be attributable to the prolonged intervention of excision repair before DNA replication during the post-treatment period. The influence of conditioned medium on the UV-induced mutation at the ouabain-resistance locus was also examined and a significant decrease in mutation frequecy was noted. The observed reduction in killing and mutation as a result of post-incubation in conditioned medium, which delays DNA replication, would be interpreted as evidence that conditioned medium provides a longer period of time for an error-free excision-repair process, leaving lesion in DNA available for error-prone post-replication repair. (Auth.)

  5. Cell inactivation and chromosomal aberrations induced by X-rays and fast neutrons in cells of the Chinese hamster. 1

    International Nuclear Information System (INIS)

    Tolkendorf, E.

    1979-01-01

    Asynchronously grown cultures of Chinese hamster cells V79-4 were irradiated in suspension with 180 kV X-rays and fast neutrons (average energy of 6.2 MeV). The damage was assessed by measuring cell survival and frequencies of chromosome aberrations in the first post-irradiation metaphases. The experimental data for survival and chromosome aberrations were fitted by computer programmes. From the fitted curves the relative biological effectiveness (RBE) of fast neutrons was calculated. The RBE shows a similar dose dependence for killed and aberrant cells. The RBE decreases with increasing dose and amounts to approximately 5 for both effects for small neutron doses. The highest RBE is found for asymmetrical chromosomal exchanges and is dependent on the neutron dose, too. However, for isochromatid deletions the RBE is dose independent with a value of 3.6. (author)

  6. Ca2+-dependent down-regulation of human histamine H1receptors in Chinese hamster ovary cells.

    Science.gov (United States)

    Hishinuma, Shigeru; Komazaki, Hiroshi; Tsukamoto, Hayato; Hatahara, Hirokazu; Fukui, Hiroyuki; Shoji, Masaru

    2018-01-01

    G q/11 protein-coupled human histamine H 1 receptors in Chinese hamster ovary cells stimulated with histamine undergo clathrin-dependent endocytosis followed by proteasome/lysosome-mediated down-regulation. In this study, we evaluated the effects of a sustained increase in intracellular Ca 2+ concentrations induced by a receptor-bypassed stimulation with ionomycin, a Ca 2+ ionophore, on the endocytosis and down-regulation of H 1 receptors in Chinese hamster ovary cells. All cellular and cell-surface H 1 receptors were detected by the binding of [ 3 H]mepyramine to intact cells sensitive to the hydrophobic and hydrophilic H 1 receptor ligands, mepyramine and pirdonium, respectively. The pretreatment of cells with ionomycin markedly reduced the mepyramine- and pirdonium-sensitive binding sites of [ 3 H]mepyramine, which were completely abrogated by the deprivation of extracellular Ca 2+ and partially by a ubiquitin-activating enzyme inhibitor (UBEI-41), but were not affected by inhibitors of calmodulin (W-7 or calmidazolium) and protein kinase C (chelerythrine or GF109203X). These ionomycin-induced changes were also not affected by inhibitors of receptor endocytosis via clathrin (hypertonic sucrose) and caveolae/lipid rafts (filipin or nystatin) or by inhibitors of lysosomes (E-64, leupeptin, chloroquine, or NH 4 Cl), proteasomes (lactacystin or MG-132), and a Ca 2+ -dependent non-lysosomal cysteine protease (calpain) (MDL28170). Since H 1 receptors were normally detected by confocal immunofluorescence microscopy with an antibody against H 1 receptors, even after the ionomycin treatment, H 1 receptors appeared to exist in a form to which [ 3 H]mepyramine was unable to bind. These results suggest that H 1 receptors are apparently down-regulated by a sustained increase in intracellular Ca 2+ concentrations with no process of endocytosis and lysosomal/proteasomal degradation of receptors. © 2017 International Society for Neurochemistry.

  7. Low doses of alpha particles do not induce sister chromatid exchanges in bystander Chinese hamster cells defective in homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, H; Wilson, P F; Chen, D J; Thompson, L H; Bedford, J S; Little, J B

    2007-10-26

    We reported previously that the homologous recombinational repair (HRR)-deficient Chinese hamster mutant cell line irs3 (deficient in the Rad51 paralog Rad51C) showed only a 50% spontaneous frequency of sister chromatid exchange (SCE) as compared to parental wild-type V79 cells. Furthermore, when irradiated with very low doses of alpha particles, SCEs were not induced in irs3 cells, as compared to a prominent bystander effect observed in V79 cells (Nagasawa et al., Radiat. Res. 164, 141-147, 2005). In the present study, we examined additional Chinese hamster cell lines deficient in the Rad51 paralogs Rad51C, Rad51D, Xrcc2, and Xrcc3 as well as another essential HRR protein, Brca2. Spontaneous SCE frequencies in non-irradiated wild-type cell lines CHO, AA8 and V79 were 0.33 SCE/chromosome, whereas two Rad51C-deficient cell lines showed only 0.16 SCE/chromosome. Spontaneous SCE frequencies in cell lines defective in Rad51D, Xrcc2, Xrcc3, and Brca2 ranged from 0.23-0.33 SCE/chromosome, 0-30% lower than wild-type cells. SCEs were induced significantly 20-50% above spontaneous levels in wild-type cells exposed to a mean dose of 1.3 mGy of alpha particles (<1% of nuclei traversed by an alpha particle). However, induction of SCEs above spontaneous levels was minimal or absent after {alpha}-particle irradiation in all of the HRR-deficient cell lines. These data suggest that Brca2 and the Rad51 paralogs contribute to DNA damage repair processes induced in bystander cells (presumably oxidative damage repair in S-phase cells) following irradiation with very low doses of alpha particles.

  8. The replication timing program of the Chinese hamster ?-globin locus is established coincident with its repositioning near peripheral heterochromatin in early G1 phase

    OpenAIRE

    Li, Feng; Chen, Jianhua; Izumi, Masako; Butler, Mark C.; Keezer, Susan M.; Gilbert, David M.

    2001-01-01

    We have examined the dynamics of nuclear repositioning and the establishment of a replication timing program for the actively transcribed dihydrofolate reductase (DHFR) locus and the silent ?-globin gene locus in Chinese hamster ovary cells. The DHFR locus was internally localized and replicated early, whereas the ?-globin locus was localized adjacent to the nuclear periphery and replicated during the middle of S phase, coincident with replication of peripheral heterochromatin. Nuclei were pr...

  9. The effect of dexamethasone on the radiation survival response and misonidazole-induced hypoxic-cell cytotoxicity in Chinese hamster cells V-79-753B in vitro

    International Nuclear Information System (INIS)

    Millar, B.C.; Jinks, S.

    1981-01-01

    Overnight exposure of Chinese hamster cells, V-79-753B, to microgram quantities of the synthetic corticosteroid, dexamethasone, resulted in a decrease in sensitivity towards radiation, both in air and in hypoxia. The effect was dose-modifying and the oxygen enhancement ratio did not change appreciably. Similarly, when dexamethasone-treated hypoxic cells were irradiated in the presence of misonidazole, a hypoxic cell radiosensitizer, there was a decrease in radiation sensitivity compared with untreated hypoxic cells irradiated with misonidazole. (author)

  10. The influence of continuous γ-irradiation at decreasing dose-rate on the survival rote and induction of gene mutations in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Feoktistova, T.P.; Elisova, E.V.; Stavrakova, N.M.

    1991-01-01

    Continuous γ-irradiation at decreasing dose-rate was shown to be less effective than acute exposure with regard to the lethal effect and frequency of mutations of resistance to 6-thioguanine in cultured Chinese hamster cells. The cell population subjected to continuons irradiation was d more radioresistant than the intact one. Lethal and genetic effects of continuous irradiation at decreasing dose-rate were mainly determined by the contribution of the radiation dose received during the first 24 h of exposure

  11. Protective action of DNA preparations on the survival of cells and yield of 8-azaguanine resistant mutations in X-irradiated cell culture of chinese hamsters

    International Nuclear Information System (INIS)

    Kuznetsova, N.N.; Feoktistova, T.P.

    1976-01-01

    A DNA preparation (molecular weight 19.6-21.0x1O 6 daltons) administered to cell culture of Chinese hamsters in concentrations of 100 to 122 μg/ml 60 minutes before and in the course of 3 days after X-irradiation (600 R) decreased the lethality of irradiated cells and reduced induction of 8-azaguanine resistant genic mutations. DNA preparations with the concentrations under study had no toxic action on cells and were not mutagenous

  12. Permeability changes and incorporation of labelled thymidine into DNA and whole cells of the fibroblast culture of Chinese hamsters affected by MEA and low temperature

    International Nuclear Information System (INIS)

    Ermekova, V.M.; Kondakova, N.V.; Levitman, M.Kh.; Saugabaeva, K.M.; Ehjdus, L.Kh.

    1976-01-01

    Action of MEA and low temperature (20degC) on the incorporation of labelled thymidine into DNA and whole cells of the fibroblast culture of chinese hamsters has been studied. It has been found that each of the above-mentioned factors equally decreases the label uptake into the cell and DNA. It is concluded that MEA and low temperature do not substantially influence the rate of DNA synthesis

  13. Effect of Wortmannin on the repair profiles of DNA double-strand breaks in the whole genome and in interstitial telomeric sequences of Chinese hamster cells

    International Nuclear Information System (INIS)

    Losada, Raquel; Rivero, Maria Teresa; Slijepcevic, Predrag; Goyanes, Vicente; Fernandez, Jose Luis

    2005-01-01

    The DNA breakage detection-fluorescence in situ hybridization (DBD-FISH) procedure was applied to analyze the effect of Wortmannin (WM) in the rejoining kinetics of ionizing radiation-induced DNA double-strand breaks (DSBs) in the whole genome and in the long interstitial telomeric repeat sequence (ITRS) blocks from Chinese hamster cell lines. The results indicate that the ITRS blocks from wild-type Chinese hamster cell lines, CHO9 and V79B, exhibit a slower initial rejoining rate of ionizing radiation-induced DSBs than the genome overall. Neither Rad51C nor the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) activities, involved in homologous recombination (HR) and in non-homologous end-joining (NHEJ) pathways of DSB repair respectively, influenced the rejoining kinetics within ITRS in contrast to DNA sequences in the whole genome. Nevertheless, DSB removal rate within ITRS was decreased in the absence of Ku86 activity, though at a lower affectation level than in the whole genome, thus homogenizing both rejoining kinetics rates. WM treatment slowed down the DSB rejoining kinetics rate in ITRS, this effect being more pronounced in the whole genome, resulting in a similar pattern to that of the Ku86 deficient cells. In fact, no WM effect was detected in the Ku86 deficient Chinese hamster cells, so probably WM does not add further impairment in DSB rejoining than that resulted as a consequence of absence of Ku activity. The same slowing effect was also observed after treatment of Rad51C and DNA-PKcs defective hamster cells by WM, suggesting that: (1) there is no potentiation of the HR when the NHEJ is impaired by WM, either in the whole genome or in the ITRS, and (2) that this impairment may probably involve more targets than DNA-PKcs. These results suggest that there is an intragenomic heterogeneity in DSB repair, as well as in the effect of WM on this process

  14. Interaction between the effects of pepleomycin with lidocaine and radiation on cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Shimada, Yuji

    1989-01-01

    The interaction of the cytotoxicities in combination use of lidocaine (LID), pepleomycin (PEP) and radiation in combined treatment was studied using Chinese hamster V79 cells by colony forming assay. LID showed no cytotoxic effect up to 12 mM when it was employed alone. However selective enhancement of the PEP cytotoxic effect appeared when the drugs were used simultaneously. The mechanism of this enhancing effect was thought to involve inhibition by LID of the repair of the cells from PEP potentially lethal damage. LID showed no enhancing effect on the radiation cytotoxicity when the agents were used simultaneously. Only an additive effect appeared when PEP and radiation were employed simultaneously. An interactive effect appeared when LID, PEP and radiation were used simultaneously, although this effect was not so significant. The enhancement ratio of PEP with LID on radiation was 1.58. The fundamental mechanism of enhancement of cytotoxic effect of LID on PEP and the interactive relationship among LID, PEP and radiation are analyzed and discussed. (author)

  15. Modification of thermal sensitivity of Chinese hamster cells by exposure to solutions of monovalent and divalent cationic salts

    International Nuclear Information System (INIS)

    Raaphorst, G.P.; Azzam, E.I.; Vadasz, J.

    1984-06-01

    Chinese hamster V79 cells were heated in culture medium or in 0.155-mol.dm -3 solutions of LiCl, NaCl, KCl, MgCl 2 , CaCl 2 and BaCl 2 . The presence of any one of these ionic solutions during heating increased the thermal sensitivity of the cells. The order of increased thermal sensitivity was KCl > LiCl > NaCl for the monovalent salts and BaCl 2 > MgCl 2 > CaCl 2 for the divalent cation salts. The addition of glucose to LiCl or NaCl solutions did not reduce the thermal sensitization caused by these solutions. When cells were sensitized by LiCl or NaCl treatment, a change in pH from 7.2 to 6.6 did not further increase thermal sensitivity. These data show that nutrient and ionic factors and their interplay are involved in cellular thermal sensitivity

  16. Interaction of leukotriene C4 and Chinese hamster lung fibroblasts (V79A03 cells). 1. Characterization of binding

    Energy Technology Data Exchange (ETDEWEB)

    Fitz, T.A.; Contois, D.F.; Liu, Y.X.; Watt, D.S.; Walden, T.L.

    1990-10-01

    A novel, specific, and potent biological action of leukotriene C4 (LTC4) was demonstrated in the Chinese Hamster lung fibroblast cell line V79A03 (V79 cells), namely the conferment of protection against subsequent irradiation. Consequently, studies were conducted to determine whether LTC4-conferred radioprotection could be attributed to a receptor-mediated phenomenon. Specific binding sites for leukotriene C4 (LTC4) were identified and characterized using intact V79 cells incubated at 4 C in the presence of serine-borate, during which time conversion of LTC4 to LTD4 or LTE4 was undetectable. Binding was maximal in a broad region between pH 6.2 and 8.8. Ca2+, Mg2+, and Na+ were not required for binding, and binding was not altered by GTP, ATP, cAMP, by leukotrienes B4, D4, or E4, or by the leukotriene end point antagonists LY 171883, FPL 55712, or Revlon 5901-5.

  17. Size distribution of fullerenol nanoparticles in cell culture medium and their influence on antioxidative enzymes in Chinese hamster ovary cells

    Directory of Open Access Journals (Sweden)

    Srđenović Branislava U.

    2015-01-01

    Full Text Available Fullerenol (C60(OH24 nanoparticles (FNP have a significant role in biomedical research due to their numerous biological activities, some of which are cytoprotective and antioxidative properties. The aim of this study was to measure distribution of fullerenol nanoparticles and zeta potential in cell medium RPMI 1640 with 10% fetal bovine serum (FBS and to investigate the influence of FNP on Chinese hamster ovary cells (CHO-K1 survival, as well as to determine the activity of three antioxidative enzymes: superoxide-dismutase, glutathione-reductase and glutathione-S-transferase in mitomycin C-treated cell line. Our investigation implies that FNP, as a strong antioxidant, influence the cellular redox state and enzyme activities and thus may reduce cell proliferation, which confirms that FNP could be exploited for its use as a cytoprotective agent.[Projekat Ministarstva nauke Republike Srbije, br. III45005 i Pokrajinski Sekretarijat za nauku i tehnološki razvoj Vojvodine, grant number 114-451-2056/2011-01

  18. Enhanced malignant transformation is accompanied by increased survival recovery after ionizing radiation in Chinese hamster embryo fibroblasts

    International Nuclear Information System (INIS)

    Boothman, D.A.

    1994-01-01

    Transformed Chinese hamster embryo fibroblasts (CHEF), which gradually increase in tumor-forming ability in nude mice, were isolated from normal diploid CHEF/18 cells. Transformed CHEF cells (i.e., T30-4 > 21-2M3 > 21-2 > normal CHEF/18) showed gradual increases in potentially lethal damage (PLD) survival recovery. β-Lapachone and camptothecin, modulators of topoisomerase I (Topo I) activity, not only prevented survival recovery in normal as well as in tumor cells, but enhanced unscheduled DNA synthesis. These seemingly conflicting results are due to the fact that Topo I activity can be modulated by inhibitors to convert single-stranded DNA lesions into double-stranded breaks. Increases in unscheduled DNA synthesis may result from a continual supply of free ends, on which DNA repair processes may act. Altering Topo I activity with modulators appears to increase X-ray lethality via a DNA lesion modification suicide pathway. Cells down-regulate Topo I immediately after ionizing radiation to prevent Topo I-mediated lesion modification and to enhance survival recovery. 16 refs., 3 figs., 1 tab

  19. Transfer of Chinese hamster DNA repair gene(s) into repair-deficient human cells (Xeroderma pigmentosum)

    International Nuclear Information System (INIS)

    Karentz, D.; Cleaver, J.E.

    1985-01-01

    Transfer of repair genes by DNA transfection into repair-deficient Xeroderma pigmentosum (XP) cells has thus far been unsuccessful, presenting an obstacle to cloning XP genes. The authors chose an indirect route to transfer repair genes in chromosome fragments. DNA repair-competent (UV resistant) hybrid cell lines were established by PEG-mediated fusions of DNA repair-deficient (UV sensitive) human fibroblasts (XP12RO) with wild type Chinese hamster (CHO) cells (AA8). CHO cells were exposed to 5 Krad X-rays prior to fusions, predisposing hybrid cells to lose CHO chromosome fragments preferentially. Repair-competent hybrids were selected by periodic exposures to UV light. Secondary and tertiary hybrid cell lines were developed by fusion of X-irradiated hybrids to XP12RO. The hybrid cell lines exhibit resistance to UV that is comparable to that of CHO cells and they are proficient at repair replication after UV exposure. Whole cell DNA-DNA hybridizations indicate that the hybrids have greater homology to CHO DNA than is evident between XP12RO and CHO. These observations indicate that CHO DNA sequences which can function in repair of UV-damaged DNA in human cells have been transferred into the genome of the repair-deficient XP12RO cells

  20. Carbamates: A study on genotoxic, cytotoxic, and apoptotic effects induced in Chinese hamster ovary (CHO-K1) cells.

    Science.gov (United States)

    Soloneski, Sonia; Kujawski, Maciej; Scuto, Anna; Larramendy, Marcelo L

    2015-08-01

    In vitro effects of the carbamates pirimicarb and zineb and their formulations Aficida® (50% pirimicarb) and Azzurro® (70% zineb), respectively, were evaluated in Chinese hamster ovary (CHO-K1) cells. Whereas the cytokinesis-blocked micronucleus cytome assay was employed to test for genotoxicity, MTT, neutral red (NR), and apoptosis evaluation were used as tests for estimating cell viability and succinic dehydrogenase activity, respectively. Concentrations tested were 10-300 μg/ml for pirimicarb and Aficida®, and 1-50 μg/ml for zineb and Azzurro®. All compounds were able to increase the frequency of micronuclei. A marked reduction in the nuclear division index was observed after treatment with 5 μg/ml of zineb and Azzurro® and 10 μg/ml of Azzurro®. Alterations in the cellular morphology not allowing the recognition of binucleated cells exposed to 300 μg/ml pirimicarb and Aficida® as well as 10-50 μg/ml zineb and Azzurro®. All four compounds induced inhibition of both cell viability and succinic dehydrogenase activity and trigger apoptosis in CHO-K1 cells, at least when exposed for 24 h. The data herein demonstrate the genotoxic and cytotoxic effects exerted by these carbamates and reveal the potential risk factor of these pesticides, still extensively used worldwide, for both human health and the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. An RNA-seq based transcriptomic investigation into the productivity and growth variants with Chinese hamster ovary cells.

    Science.gov (United States)

    Sha, Sha; Bhatia, Hemlata; Yoon, Seongkyu

    2018-02-21

    Chinese hamster ovary (CHO) cells are widely used in producing monoclonal antibodies (mAbs), however, these cell lines can show variants associated with productivity and growth. Fundamental understanding of cellular mechanisms can benefit high mAbs production while maintaining robust cell growth. In this study, RNA sequencing (RNA-seq) based approach was used to study the transcriptomic space among three mAb-producing CHO cell lines. A phenotypic contrast of higher productivity but lower growth was found with one cell line versus the other two cell lines. The messenger RNAs (mRNAs) from those cells at two different time points in culture were sequenced to seek the gene functions possibly associated with the phenotypic differences. It was found that the mAb transcripts from each cell line were correlated with the mAb production level, indicating a strong determination of production by the expression level of gene of interest (GOI). Further exploration in the global transcriptome showed that the high producers had more expression with genes related with secretion and protein transportation. In the meantime, the slower growth of the high producers was linked to higher regulation to cell growth as well as lower gene expression on biosynthesis, central metabolism and nutrient transport. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Interaction between the effects of pepleomycin with lidocaine and radiation on cultured Chinese hamster V79 cells

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Yuji

    1989-02-01

    The interaction of the cytotoxicities in combination use of lidocaine (LID), pepleomycin (PEP) and radiation in combined treatment was studied using Chinese hamster V79 cells by colony forming assay. LID showed no cytotoxic effect up to 12 mM when it was employed alone. However selective enhancement of the PEP cytotoxic effect appeared when the drugs were used simultaneously. The mechanism of this enhancing effect was thought to involve inhibition by LID of the repair of the cells from PEP potentially lethal damage. LID showed no enhancing effect on the radiation cytotoxicity when the agents were used simultaneously. Only an additive effect appeared when PEP and radiation were employed simultaneously. An interactive effect appeared when LID, PEP and radiation were used simultaneously, although this effect was not so significant. The enhancement ratio of PEP with LID on radiation was 1.58. The fundamental mechanism of enhancement of cytotoxic effect of LID on PEP and the interactive relationship among LID, PEP and radiation are analyzed and discussed. (author).

  3. Inhibition of replicon initiation and DNA elongation in Chinese hamster ovary cells by treatment at 45.5 degrees C

    International Nuclear Information System (INIS)

    Wong, R.S.; Dewey, W.C.

    1982-01-01

    Heat treatment of Chinese hamster ovary cells at 45.5 degrees C for 15 minutes resulted in the inhibition of both the replicon initiation and the DNA elongation processes. Analysis of the DNA made after treatment showed that for up to 30 minutes after hyperthermia, there was a significant increase (45-80% above control level) in the amount of labeled DNA less than or equal to 40S in size and having a distinct peak of 20S. Therefore, elongation of 20S molecules into larger molecules was inhibited or slowed down. These small molecules did not accumulate when recovery times were longer than 30 minutes. The DNA made after 120 and 240 minutes postheat incubation was larger than control size and indicated that, although replicon initiation was still inhibited, elongation between replicons into 120S molecules could take place. However, their subsequent elongation into parental-size molecules was inhibited. The same delay in DNA elongation seen in cells examined immediately after treatment was still observed in cells heated and allowed to recover for 30 minutes. Also, after 30 minutes of recovery, heated cells still had more newly synthesized DNA in the single-stranded fraction than did control cells, which indicates that DNA elongation within a replicon is delayed for at least 30 minutes after heating. Furthermore, at 4 hours after heating, the inhibition of elongation of clusters of replicons into parental molecules prevailed

  4. Phosphatidylserine biosynthesis in cultured Chinese hamster ovary cells. III. Genetic evidence for utilization of phosphatidylcholine and phosphatidylethanolamine as precursors

    International Nuclear Information System (INIS)

    Kuge, O.; Nishijima, M.; Akamatsu, Y.

    1986-01-01

    We reported that Chinese hamster ovary (CHO) cells contain two different serine-exchange enzymes (I and II) which catalyze the base-exchange reaction of phospholipid(s) with serine and that a phosphatidylserine-requiring mutant (strain PSA-3) of CHO cells is defective in serine-exchange enzyme I and lacks the ability to synthesize phosphatidylserine. In this study, we examined precursor phospholipids for phosphatidylserine biosynthesis in CHO cells. When mutant PSA-3 and parent (CHO-K1) cells were cultured with [ 32 P]phosphatidylcholine, phosphatidylserine in the parent accumulated radioactivity while that in the mutant was not labeled significantly. On the contrary, when cultured with [ 32 P]phosphatidylethanolamine, the mutant incorporated the label into phosphatidylserine more efficiently than the parent. Furthermore, we found that mutant PSA-3 grew normally in growth medium supplemented with 30 microM phosphatidylethanolamine as well as phosphatidylserine and that the biosynthesis of phosphatidylserine in the mutant was normal when cells were cultured in the presence of exogenous phosphatidylethanolamine. The simplest interpretation of these findings is that phosphatidylserine in CHO cells is biosynthesized through the following sequential reactions: phosphatidylcholine----phosphatidylserine----phosphatidylethanolamine--- - phosphatidylserine. The three reactions are catalyzed by serine-exchange enzyme I, phosphatidylserine decarboxylase, and serine-exchange enzyme II, respectively

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

    Energy Technology Data Exchange (ETDEWEB)

    Bohrman, J.S.; Burg, J.R.; Elmore, E.; Gulati, D.K.; Barfknecht, T.R.; Niemeier, R.W.; Dames, B.L.; Toraason, M.; Langenbach, R.

    1988-01-01

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

  6. Template free synthesis of silver-gold alloy nanoparticles and cellular uptake of gold nanoparticles in Chinese Hamster Ovary cell

    International Nuclear Information System (INIS)

    Pal, Angshuman; Shah, Sunil; Kulkarni, Vijay; Murthy, R.S.R.; Devi, Surekha

    2009-01-01

    Gold-silver alloy nanoparticles were synthesized by simultaneous reduction of varying mole fractions of HAuCl 4 and AgNO 3 by sodium citrate in aqueous solution without using stabilizing agents such as surfactant or polymer. Appearance of single absorption peak in visible spectrum indicated formation of homogeneous gold-silver alloy nanoparticles. Transmission electron micrographs also support formation of alloy nanoparticles rather than core-shell particles. The plasmon absorption bands for Au-Ag nanoparticles show linear bathochromic shift with increasing Au content. No significant change in surface plasmon band was observed on storage of samples at 25 ± 2 deg. C for 6 months, indicating stability of the particles. Particle size distribution, zeta-potential and conduction of these colloidal suspensions were measured by dynamic light scattering along with Zetasizer. Gold and Au-Ag alloy nanoparticles exhibited fluorescence at 600 nm and in between 600 and 486 nm respectively depending on alloy composition. Gold nanoparticles were used for cell line study using liposome as a carrier. This liposome entrapped gold nanoparticles showed enhanced uptake by Chinese Hamster Ovary (CHO) cells compared to gold nanoparticles

  7. Effects of turmeric and its active principle, curcumin, on bleomycin-induced chromosome aberrations in Chinese hamster ovary cells

    Directory of Open Access Journals (Sweden)

    Araújo Maria Cristina P.

    1999-01-01

    Full Text Available Naturally occurring antioxidants have been extensively studied for their capacity to protect organisms and cells from oxidative damage. Many plant constituents including turmeric and curcumin appear to be potent antimutagens and antioxidants. The effects of turmeric and curcumin on chromosomal aberration frequencies induced by the radiomimetic agent bleomycin (BLM were investigated in Chinese hamster ovary (CHO cells. Three concentrations of each drug, turmeric (100, 250 and 500 mg/ml and curcumin (2.5, 5 and 10 mg/ml, were combined with BLM (10 mg/ml in CHO cells treated during the G1/S, S or G2/S phases of the cell cycle. Neither turmeric nor curcumin prevented BLM-induced chromosomal damage in any phases of the cell cycle. Conversely, a potentiation of the clastogenicity of BLM by curcumin was clearly observed in cells treated during the S and G2/S phases. Curcumin was also clastogenic by itself at 10 µg/ml in two protocols used. However, the exact mechanism by which curcumin produced clastogenic and potentiating effects remains unknown.

  8. New cell line development for antibody-producing Chinese hamster ovary cells using split green fluorescent protein

    Directory of Open Access Journals (Sweden)

    Kim Yeon-Gu

    2012-05-01

    Full Text Available Abstract Background The establishment of high producer is an important issue in Chinese hamster ovary (CHO cell culture considering increased heterogeneity by the random integration of a transfected foreign gene and the altered position of the integrated gene. Fluorescence-activated cell sorting (FACS-based cell line development is an efficient strategy for the selection of CHO cells in high therapeutic protein production. Results An internal ribosome entry site (IRES was introduced for using two green fluorescence protein (GFP fragments as a reporter to both antibody chains, the heavy chain and the light chain. The cells co-transfected with two GFP fragments showed the emission of green fluorescence by the reconstitution of split GFP. The FACS-sorted pool with GFP expression had a higher specific antibody productivity (qAb than that of the unsorted pool. The qAb was highly correlated with the fluorescence intensity with a high correlation coefficient, evidenced from the analysis of median GFP and qAb in individual selected clones. Conclusions This study proved that the fragment complementation for split GFP could be an efficient indication for antibody production on the basis of high correlation of qAb with reconstitution of GFP. Taken together, we developed an efficient FACS-based screening method for high antibody-producing CHO cells with the benefits of the split GFP system.

  9. Semi-conservative synthesis of DNA in UV-sensitive mutant cells of Chinese hamster after UV-irradiation

    International Nuclear Information System (INIS)

    Vikhanskaya, F.L.; Khrebtukova, I.A.; Manuilova, E.S.

    1985-01-01

    A study was made of the rate of semi-conservative DNA synthesis in asynchronous UV-resistant (clone V79) and UV-sensitive clones (VII and XII) of Chinese hamster cells after UV-irradiation. In all 3 clones studied, UV-irradiation (5-30 J/m 2 ) induced a decrease in the rate of DNA synthesis during the subsequent 1-2 h. In the resistant clone (V79) recovery of DNA synthesis rate started after the first 2 h post-irradiation (5 J/m 2 ) and by the 3rd hour reached its maximum value, which constituted 70% of that observed in control, non-irradiated cells. The UV-sensitive mutant clones VII and XII showed no recovery in the rate of DNA synthesis during 6-7 h post-irradiation. The results obtained show that the survival of cells is correlated with the ability of DNA synthesis to recover after UV-irradiation in 3 clones studied. The observed recovery of UV-inhibited DNA synthesis in mutant clones may be due to certain defects in DNA repair. (orig.)

  10. Effects of hyperthermia and x irradiation on sister chromatid exchange (SCE) frequency in Chinese hamster ovary (CHO) cells

    International Nuclear Information System (INIS)

    Livingston, G.K.; Dethlefsen, L.A.

    1979-01-01

    The BrdUrd labeling method was used to evaluate the effects of hyperthermia, x irradiation, and the combined treatment on the incidence of sister chromatid exchange (SCE) in Chinese hamster ovary (CHO) cells. Cells cultured in McCoy's 5A media containing 10 μM 5-bromodeoxyuridine were synchronized after one cell cycle by mitotic shake-off. Early-G 1 cells were heated by submerging culture flasks in a 44 +- 0.05 0 C water bath for periods of 20, 40, and 60 min. By the same method, other cultures were x irradiated at doses of 100, 200, 400, and 600 rad. A third protocol involved combined treatment of 20 min at 44 0 C followed immediately by one of the above radiation doses. A fourth protocol reversed the sequence of the combined treatment applying x irradiation (200 or 400 rad) followed immediately by hyperthermia. The data showed that hyperthermia and x irradiation both elevated the frequency of SCEs significantly whether applied separately or together. The combined treatment (heat: 20 min at 44 0 C plus varying x-radiation doses) produced results suggestive of a synergistic interaction. The sequence of the heat and x irradiation did not appear to have a significant effect on the production of SCE

  11. Mutation to ouabain-resistance in Chinese hamster cells: induction by ethyl methanesulphonate and lack of induction by ionising radiation

    International Nuclear Information System (INIS)

    Thacker, J.; Stephens, M.A.; Stretch, A.

    1978-01-01

    The spontaneous frequency of mutants resistant to growth inhibition by ouabian (OUAsup(R) mutants) was found to be about 5.10 -5 per viable cell in uncloned cultures of Chinese hamster V79-4 cells. In freshly-isolated clones or cultures started from a few cells this frequency was initially reduced to about 1.10 -6 in 1 mM ouabain. No increase in the frequency of OUAsup(R) mutants was found in cultures treated with γ-rays despite exploration of such variables as radiation dose, ouabain concentration, post-treatment interval before selection, cell density in selective medium, and clonal state of the cells at the time of adding ouabain (in situ vs. respreading method). A similar negative result was found for accelerated helium ions, for which the mutagenic effectiveness per unit dose has been shown to be about 10 times higher than γ-rays for the induction of thioguanine-resistant mutants in these cells. Recent evidence is reviewed in support of the suggestion that ionising radiation is unable to induce OUAsup(R) mutants because of the severity of the genetic damage it causes. (Auth.)

  12. Relative biological efficiency of intermediate energy neutrons and 60Co rays for induction of chromosomal aberrations in Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Sturelid, S.; Bergman, R.

    1976-01-01

    Intermediate energy neutrons are unique in that a considerable fraction of critical interactions and of dose absorbed is not associated with ionization but with atomic collision. It is still unknown to what extent the qualitative difference in primary damage after atomic collision compared to that of ionization and excitation becomes expressed at biological levels. Chromosomal aberrations were studied in Chinese hamster fibroblasts exposed for 5-8 hours at 22 degree C to intermediate energy neutrons, mean energy 8.5 keV, or to 60 Co-gamma rays. RBE at the 10 per cent aberration frequency level in S-phase were 2.2+-0.6 for total aberrations, 2.1+-0.6 for chromatid breaks and 1.8+-0.5 for exchanges. For each chromatid aberration observed after recovery, about 200 bondbreaking atomic collisions besides 3000 primary iniozations should have occured in DNA. However, the extent to which the aberration response is due to atomic collisions is not clear. (author)

  13. Laser-UV-microirradiation of Chinese hamster cells: the influence of the distribution of photolesions on unscheduled DNA synthesis

    International Nuclear Information System (INIS)

    Cremer, C.; Jabbur, G.

    1981-01-01

    Fibroblastoid Chinese hamster cells synchronized by mitotic selection were microirradiated in G1, using a low power laser-UV-microbeam (lambda = 257 nm). The incident energy was either concentrated on a small part of the nucleus (mode 1) or distributed over the whole nucleus (mode 11). Using the same incident UV energy, the local UV fluences were estimated to differ by two orders of magnitude. Following microirradiation the cells were incubated with [ 3 H]-thymidine for 2 h and thereafter processed for autoradiography. Silver grains were concentrated over the microirradiated part after mode 1 and distributed over the whole nucleus after mode 11 irradiation. To quantify the amount of unscheduled DNA synthesis, the number of grains per nucleus was determined. It increased with the total incident energy, but was not or only slightly affected by the mode of microirradiation, if appropriate autoradiographic conditions were used. The findings suggest that within the investigated range of energy densities (2.7-1000 J/m 2 ), the total amount of unscheduled DNA synthesis depends on the total number of pyrimidine dimers but not on their distribution in nuclear DNA. (author)

  14. Chinese hamster ovary cell mitosis and its response to ionizing radiation: A morphological analysis of the living cell

    International Nuclear Information System (INIS)

    Carlson, J.G.

    1989-01-01

    Repeated microscopic observations of exponentially growing Chinese hamster ovary cells were made and the times and mitotic stages were recorded in control and irradiated cultures at 37 degree C. As determined by autoradiography, the time from the end of S phase to early prophase (the G2 phase) was 46 min, to breakdown of the nuclear envelope was 91 min, and to restoration of the nuclear envelope was 116 min. The time spent in morphologically distinguishable phases of mitosis and the effects of 0.5, 1.0, 1.5, 2.0, and 4.0 Gy of gamma or X radiation on cells at each phase were determined. Affected cells were found to be delayed without or with reversion to an earlier mitotic stage before recovering and advancing through mitosis. Cells were timed in the five steps comprising delay with reversion: inertia, cessation I, regression, cessation II, and reprogression. No cells treated in late prophase, i.e., within 8-10 min of nuclear envelope breakdown, were delayed by the doses used; therefore the critical or transition point must be situated in middle prophase. Cells irradiated in this stage were not delayed by 0.5 or 1.0 Gy, but suffered a dose-dependent delay with or without reversion after 1.5, 2.0, and 4.0 Gy. Cells irradiated in early prophase and very late interphase responded similarly, but a greater percentage of the latter reverted

  15. Inhibition and recovery of the rate of DNA synthesis in V79 Chinese hamster cells following ultraviolet light irradiation

    International Nuclear Information System (INIS)

    Ventura, A.M.; Meneghini, R.

    1984-01-01

    Chinese hamster fibroblasts (V79 cell line) exhibit the phenomenon of recovery of DNA synthesis from the initial inhibition observed after ultraviolet light irradiation, in the absence of significant excision of pyrimidine dimers. In an attempt to determine whether the initial inhibition and subsequent recovery can be accounted for by parallel variations in the rate of movement of the replication fork, the cells were pulse-labeled with radioactive bromodeoxyuridine at different times following irradiation and their DNA centrifuged in neutral CsCl density gradients. When DNA synthesis inhibition was at a maximum, an accumulation of DNA, of density intermediate between hybrid and nonsubstituted DNA, was noticed in the density-distribution profiles. The density distribution of DNA along the gradient can provide an estimate of the rate of movement of the replication fork, and the results indicate that most of the variation in the overall rate of DNA synthesis can be accounted for by a parallel variation in the rate of fork movement. (Auth.)

  16. Characterization of Na+-linked and Na+-independent Cl-/HCO3- exchange systems in Chinese hamster lung fibroblasts

    International Nuclear Information System (INIS)

    Cassel, D.; Scharf, O.; Rotman, M.; Cragoe, E.J. Jr.; Katz, M.

    1988-01-01

    The PS120 variant of Chinese hamster lung fibroblasts which lacks Na + /H + exchange activity was used to investigate bicarbonate transport systems and their role in intracellular pH (pH/sub i/) regulation. When pH/sub i/ was decreased by acid load, bicarbonate caused pH/sub i/ increase and stimulated 36 Cl - efflux from the cells, both in a Na + -dependent manner. These results together with previous findings that bicarbonate stimulates 22 Na + uptake in PS120 cells demonstrate the presence of a Na + -linked Cl - /HCO 3 - exchange system. In cells with normal initial pH/sub i/, bicarbonate caused Na + -independent pH/sub i/ increase in Cl - -free solutions and stimulated Na + -independent 36 Cl - efflux, indicating that a Na + -independent Cl - /HCO 3 - exchanger is also present in the cell. Na + -linked and Na + -independent Cl - /HCO 3- exchange is apparently mediated by two distinct systems, since a [(tetrahydrofluorene-7-yl)oxy]acetic acid derivative selectively inhibits the Na + -independent exchanger. An additional distinctive features is a 10-fold lower affinity for chloride of the Na + -linked exchanger. The Na + -linked and Na + -independent Cl - /HCO 3 - exchange systems are likely to protect the cell from acid and alkaline load, respectively

  17. Molecular characterization of the AdeI mutant of Chinese hamster ovary cells: a cellular model of adenylosuccinate lyase deficiency.

    Science.gov (United States)

    Vliet, Lydia K; Wilkinson, Terry G; Duval, Nathan; Vacano, Guido; Graham, Christine; Zikánová, Marie; Skopova, Vaclava; Baresova, Veronika; Hnízda, Aleš; Kmoch, Stanislav; Patterson, David

    2011-01-01

    Adenylosuccinate lyase (ADSL, E. C. 4.3.2.2) carries out two non-sequential steps in de novo AMP synthesis, the conversion of succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazolecarboxamide ribotide (AICAR) and the conversion of succinyl AMP (AMPS) to AMP. In humans, mutations in ADSL lead to an inborn error of metabolism originally characterized by developmental delay, often with autistic features. There is no effective treatment for ADSL deficiency. Hypotheses regarding the pathogenesis include toxicity of high levels of SAICAR, AMPS, or their metabolites, deficiency of the de novo purine biosynthetic pathway, or lack of a completely functional purine cycle in muscle and brain. One important approach to understand ADSL deficiency is to develop cell culture models that allow investigation of the properties of ADSL mutants and the consequences of ADSL deficiency at the cellular level. We previously reported the isolation and initial characterization of mutants of Chinese hamster ovary (CHO-K1) cells (AdeI) that lack detectable ADSL activity, accumulate SAICAR and AMPS, and require adenine for growth. Here we report the cDNA sequences of ADSL from CHO-K1 and AdeI cells and describe a mutation resulting in an alanine to valine amino acid substitution at position 291 (A291V) in AdeI ADSL. This substitution lies in the "signature sequence" of ADSL, inactivates the enzyme, and validates AdeI as a cellular model of ADSL deficiency. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Isolation and characterization of a Chinese hamster ovary cell line deficient in fatty alcohol:NAD+ oxidoreductase activity

    International Nuclear Information System (INIS)

    James, P.F.; Lee, J.; Rizzo, W.B.; Zoeller, R.A.

    1990-01-01

    The authors have isolated a mutant Chinese hamster ovary cell line that is defective in long-chain fatty alcohol oxidation. The ability of the mutant cells to convert labeled hexadecanol to the corresponding fatty acid in vivo was reduced to 5% of the parent strain. Whole-cell homogenates from the mutant strain, FAA.1, were deficient in long-chain fatty alcohol:NAD + oxidoreductase activity, which catalyzes the oxidation of hexadecanol to hexadecanoic acid, although the intermediate fatty aldehyde was formed normally. A direct measurement of fatty aldehyde dehydrogenase showed that the FAA.1, strain was defective in this component of FAO activity. FAA.1 is a two-stage mutant that was selected from a previously described parent strain, ZR-82, which is defective in ether lipid biosynthesis and peroxisome assembly. Because of combined defects in ether lipid biosynthesis and fatty alcohol oxidation, the ability of the FAA.1 cells to incorporate hexadecanol into complex lipids was greatly impaired, resulting in a 60-fold increase in cellular fatty alcohol levels. As the FAO deficiency in FAA.1 cells appears to be identical to the defect associated with the human genetic disorder Sjoegren-Larsson syndrome, the FAA.1 cell line may be useful in studying this disease

  19. Changes in repair competency after 5-bromodeoxyuridine pulse labeling and near-ultraviolet light. [V79 Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, M.P.; Elkind, M.M.

    1979-07-01

    Synchronized V79 Chinese hamster cells, pulse-labeled with 5-bromodeoxyuridine (BrdUrd), show marked changes in the sensitivity to near-ultraviolet light during the cell cycle. Cells are least sensitive during the remainder of the S-phase after the BrdUrd pulse. They become maximally sensitive in the next cell cycle when the BrdUrd-labeled DNA presumably serves as the template for replication. This is followed by a return to relative insensitivity during the remainder of that S-phase. When BrdUrd is given both near the beginning and again near the end of the same S-phase, the increase in survival does not occur until DNA synthesis progresses beyond the time when the DNA made during the second pulse serves as a template. Furthermore, cells in the resistant phases of the cell cycle are sensitized by 1-2 mM caffeine. Survival curves are shown for the various cell ages of interest and are discussed in relation to the observed changes in functional repair capacity. The data support the hypothesis that lesions in the BrdUrd-containing DNA are effectively repaired after semiconservative replication. The data indicate that saturation of repair capacity and not target multiplicity is responsible for the appearance of a shoulder on these survival curves.

  20. Effects of ultraviolet irradiation on the rate and sequence of DNA replication in synchronized Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Meyn, R.E.; Hewitt, R.R.; Thomson, L.F.; Humphrey, R.M.

    1976-05-01

    The effects of ultraviolet light (uv) irradiation on the rate of DNA replication in synchronized Chinese hamster ovary (CHO) cells were investigated. A technique for measuring semiconservative DNA replication was employed that involved growing the cells in medium containing 5-bromodeoxyuridine and subsequently determining the amount of DNA that acquired hybrid buoyant density in CsCl density gradients. One of the advantages of this technique was that it allowed a characterization of the extent of DNA replication as well as rate after irradiation. It was found that while there was a dose-dependent reduction in the rate of DNA replication following uv-irradiation, doses of up to 10 J/m/sup 2/ (which produce many dimers per replicon) did not prevent the ultimate replication of the entire genome. Hence, we conclude that dimers cannot be absolute blocks to DNA replication. In order to account for the total genome replication observed, a mechanism must exist that allows genome replication between dimers. The degree of reduction in the rate of replication by uv was the same whether the cells were irradiated at the Gl-S boundary or 1 h into S-phase. Previous work had shown that cells in early S-phase are considerably more sensitive to uv than cells at the G1-S boundary. Experiments specifically designed to test for reiterative replication showed that uv does not induce a second round of DNA replication within the same S-phase.

  1. Lindane-induced cytotoxicity and the role of vitamin E in Chinese Hamster Ovary (CHO-K1) cells.

    Science.gov (United States)

    Kmetic, Ivana; Radosević, Kristina; Murati, Teuta; Simić, Branimir; Kniewald, Zlatko; Kniewald, Jasna

    2009-10-01

    Lindane, a toxic insecticide from the persistent organic pollutants (POP's) group, may act as an endocrine disrupter affecting crucial tissues of reproductive system. In this study a Chinese Hamster Ovary cell line (CHO-K1) was applied to assess the potential of lindane cytotoxicity at the cellular level. The methods of Trypan blue exclusion, MTT and Kenacid blue assays were used to assess cytotoxicity and confirmed a decrease in the number of viable CHO-K1 cells at 34.4-344 microM lindane during 24, 48 and 72 hours of exposure. The cell proliferation tests showed significant inhibition (p < 0.025-0.001 vs control) and a progressive increase in toxicity with increasing lindane concentrations. Corresponding IC(50) values were determined with each applied method. After 72 h of lindane exposure, IC(50) values were 184 microM according to the Trypan blue method and 272 and 256 microM with the Kenacid blue and MTT assays, respectively. Morphological changes induced by the cytotoxicity of lindane were followed by the fluorescence microscopy and only necrotic cells were detected. Vitamin E (25 and 50 microg/mL) was used for protection of ovarian cells against lidane-induced oxidative stress damage, and lipid peroxidation was postulated as a possible mechanism of lindane toxicity. The viability of cells pre-incubated with vitamin E was significantly enhanced (up to p < 0.025) compared to the results observed in cells exposed to lindane only, but vitamin E treatment could not prevent complete lindane-induced cytotoxicity. Results suggest that vitamin E may exert a slightly protective role in cell defense against lipophilic pro-oxidant xenobiotics such as lindane.

  2. Interaction of leukotriene C4 and Chinese hamster lung fibroblasts (V79A03 cells). 1. Characterization of binding.

    Science.gov (United States)

    Fitz, T A; Contois, D F; Liu, Y X; Watt, D S; Walden, T L

    1990-10-01

    A novel, specific, and potent biological action of leukotriene C4 (LTC4) was demonstrated in the Chinese hamster lung fibroblast cell line V79A03 (V79 cells), namely the confirment of protection against subsequent gamma-irradiation. Consequently, studies were conducted to determine whether LTC4-conferred radioprotection could be attributed to a receptor-mediated phenomenon. Specific binding sites for leukotriene C4 (LTC4) were identified and characterized using intact V79 cells incubated at 4 degrees C in the presence of serine-borate, during which time conversion of LTC4 to LTD4 or LTE4 was undetectable. Binding was maximal in a broad region between pH 6.2 and 8.8. Ca2+, Mg2+, and Na+ were not required for binding, and binding was not altered by GTP, ATP, or cAMP, by leukotrienes B4, D4, or E4, or by the leukotriene end point antagonists LY 171883, FPL 55712, or Revlon 5901-5. Scatchard analyses and kinetic experiments indicated the presence of high-affinity [Kd = 2.5 +/- 0.63 nM, approximately 9.9 x 10(5) sites/cell] and low-affinity [Kd = 350 +/- 211 nM, approximately 2.7 x 10(6) sites/cell] binding sites. The observed binding characteristics of LTC4 to V79 cells are consistent with a receptor-mediated phenomenon. In a companion communication which follows this report, we report the subcellular distribution of LTC4 binding to V79 cells and demonstrate that this binding is unlikely to be attributed principally to interaction with glutathione-S-transferase.

  3. Protective effect of propolis on radiation-induced chromosomal damage on Chinese hamster ovary cells (CHO-K1)

    Energy Technology Data Exchange (ETDEWEB)

    Spigoti, Geyza; Bartolini, Paolo; Okazaki, Kayo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: kokazaki@ipen.br; Tsutsumi, Shiguetoshi [Amazon Food Ltd., Tokyo (Japan)], e-mail: fwip5138@mb.infoweb.ne.jp

    2009-07-01

    In the last years, particular interest has been given to investigations concerning natural, effective and nontoxic compounds with radioprotective capacity in concert with increasing utilization of different types of ionizing radiation for various applications. Among them, propolis, a resinous mixture of substances collected by honey bees (Apis mellifera) has been considered promising since it presents several advantageous characteristics, i.e., antiinflammatory, anticarcinogenic, antimicrobial and free radical scavenging action. It is, therefore, a direct antioxidant that protects cells and organisms from the adverse effects of ionizing radiation. These relevant biological activities are mainly mediated by the flavonoids, present at relatively high concentrations in the propolis. Considering that the chemical composition and, consequently, the biological activity of propolis is variable according to the environmental plant ecology, the present study was conducted in order to evaluate the radioprotective capacity of Brazilian propolis, collected in the State of Rio Grande do Sul, against genotoxic damages induced by {sup 60}Co {gamma}-radiation in Chinese hamster ovary cells (CHO-K1). for this purpose, micronucleus induction was analyzed concerning irreparable damage, specifically related to DNA double-strand breaks, that are potentially carcinogenic. CHO-K1 cells were submitted to different concentrations of propolis (3 - 33 {mu}g/ml), 1 h before irradiation, with 1 Gy of {gamma} radiation (0.722 Gy/min). The data obtained showed a decreasing tendency in the quantity of radioinduced damage on cells previously treated with propolis. The radioprotective effect was more prominent at higher propolis concentration. The treatment with propolis alone did not induce genotoxic effects on CHO-K1 cells. Beside that, the treatment with propolis, associated or not with radiation, did not influence the kinetics of cellular proliferation. (author)

  4. Radioprotective action of WR-1065 on radiation-induced DNA strand breaks in cultured Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Murray, D.; VanAnkeren, S.C.; Milas, L.; Meyn, R.E.

    1988-01-01

    We have examined the radioprotective effect of WR-1065 on cultured Chinese hamster ovary cells. The effects of the drug on the induction and rejoining of gamma-ray-induced DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) were measured using alkaline (pH 12.1) and neutral (pH 7.0) elution, respectively. Molecular protection factors (PFs) calculated from these data allowed us to determine whether the degree of modification of strand breakage accurately predicted the PFs measured using the biological end point of cell survival. The drug did protect against the induction of both SSBs and DSBs, although to an extent that did not appear to fully account for the degree of radioprotection in terms of cell killing measured under identical conditions. It is therefore unlikely that radioprotection by WR-1065 occurs simply as a consequence of a general lowering of all types of gamma-ray-induced DNA lesions, and it is possible that the drug could differentially protect against the induction of subsets of these DNA lesions. The rate of SSB rejoining was retarded following preirradiation treatment of cells with WR-1065, but there was no effect on DSB rejoining. Postirradiation treatment with WR-1065 also appeared to retard SSB rejoining but without an accompanying effect on either DSB rejoining or cell survival; however, this effect was largely reversed by the addition of catalase and was, therefore, probably a result of H 2 O 2 generated by autoxidation of the drug. Based on these observations, it would appear that the molecular actions of aminothiol radioprotective compounds that lead to reduced cell killing are much more complex than previously thought

  5. Neocarzinostatin-mediated DNA damage and repair in wild-type and repair-deficient Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Kuo, W.L.; Meyn, R.E.; Haidle, C.W.

    1984-01-01

    The formation and repair of neocarzinostatin (NCS)-mediated DNA damage were examined in two strains of Chinese hamster ovary cells. The response in strain EM9, a mutant line selected for its sensitivity to ethyl methanesulfonate and shown to have a defect in the repair of X-ray-induced DNA breaks, was compared with that observed in the parental strain (AA8). The DNA strand breaks and their subsequent rejoining were measured using the method of elution of DNA from filters under either alkaline (for single-strand breaks), or nondenaturing conditions (for double-strand breaks). Colony survival assays showed that the mutant was more sensitive to the action of NCS than was the parental strain by a factor of approximately 1.5. Elution analyses showed that the DNA from both strains was damaged by NCS; the mutant displayed more damage than the parent under the same treatment conditions. Single-strand breaks were produced with a frequency of about 10 to 15 times the frequency of double-strand breaks. Both strains were able to rejoin both single-strand breaks and double-strand breaks induced by NCS treatment. The strand break data suggest that the difference in NCS-mediated cytotoxicity between EM9 and AA8 cells may be directly related to the enhanced production of DNA strand breaks in EM9. However, the fact that much higher doses of NCS were required in the DNA studies compared to the colony survival assays implies that either a small number of DNA breaks occur in a critical region of the genome, or that lesions other than DNA strand breaks are partly responsible for the observed cytotoxicity

  6. Hyperthermic survival of Chinese hamster ovary cells as a function of cellular population density at the time of plating

    International Nuclear Information System (INIS)

    Highfield, D.P.; Holahan, E.V.; Holahan, P.K.; Dewey, W.C.

    1984-01-01

    The survival of synchronous G 1 or asynchronous Chinese hamster ovary cells in vitro to heat treatment may depend on the cellular population density at the time of heating and/or as the cells are cultured after heating. The addition of lethally irradiated feeder cells may increase survival at 10 -3 by as much as 10- to 100-fold for a variety of conditions when cells are heated either in suspension culture or as monolayers with or without trypsinization. The protective effect associated with feeder cells appears to be associated with close cell-to-cell proximity. However, when cells are heated without trypsinization about 24 hr or later after plating, when adaptation to monolayer has occurred, the protective effect is reduced; i.e., addition of feeder cells enhances survival much less, for example, about 2- to 3-fold at 10 -2 -10 -3 survival. Also, the survival of a cell to heat is independent of whether the neighboring cell in a microcolony is destined to live or die. Finally, if protective effects associated with cell density do occur and are not controlled, serious artifacts can result as the interaction of heat and radiation is studied; for example, survival curves can be moved upward, and thus changed in shape as the number of cells plated is increased with an increase in the hyperthermic treatment or radiation dose following hyperthermia. Therefore, to understand mechanisms and to obtain information relevant to populations of cells in close proximity, such as those in vivo, these cellular population density effects should be considered and understood

  7. Nicotinamide starvation and inhibition of poly(ADP-Ribose) synthesis enhance the induced mutation in Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Okada, Gensaku; Kaneko, Ichiro; Mitsui, Hideki.

    1987-01-01

    The effects of nicotinamide (NA) deficiency and added NA and 3-aminobenzamide (3AB) on the cytotoxicity and the induction of mutations in Chinese hamster V79-14 cells were investigated. In NA deficiency the addition of NA (up to 4 mM) and 3AB (up to 7.5 mM) was not cytotoxic. The presence of NA prior to exposure to mitomycin C (MMC) or γ-rays produced a dose-dependent increase in the relative cloning ability of DNA-damaged cells. The lethality of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was significantly potentiated by pre-treatment with 5 mM 3AB, but no potentiation by 3AB was observed for MMC, ultraviolet (UV)-B light, or γ-rays. Among cells pre-cultured in NA-free medium there were increased frequencies of mutations at both the hypoxanthineguanine phosphoribosyltransferase (HGPRT) and the adenine phosphoribosyltransferase (APRT) loci following DNA damage. The enhancing effect by NA deficiency was time-dependent. Incubation with NA prior to DNA damage produced a significant reduction in the frequency of mutations. The addition of 3AB to the nicotinamide adenine dinucleotide (NAD + )-depleted cell cultures before or after the DNA damage also strongly increased the frequency of induced mutations, with increasing concentrations of 3AB up to 5 mM, but the frequency was reduced at higher concentrations. The interaction between NA deficiency and the addition of 3AB appears to act synergistically on mutation induction. A correlation was observed between the potential of inhibiting poly (ADP-ribose) polymerase and the enhancement of mutation frequency. (author)

  8. Agricultural irrigation mediates climatic effects and density dependence in population dynamics of Chinese striped hamster in North China Plain.

    Science.gov (United States)

    Yan, Chuan; Xu, Lei; Xu, Tongqin; Cao, Xiaoping; Wang, Fusheng; Wang, Shuqing; Hao, Shoushen; Yang, Hefang; Zhang, Zhibin

    2013-03-01

    Several studies show that climatic (extrinsic) factors can interact with density-dependent (intrinsic) factors to alter long-term population dynamics, yet there is a surprising lack of investigations of how anthropogenic disturbance modifies such dynamics. Such interactions could be especially important in agricultural systems subject to climate change. We investigated the effects of density dependence, climate, recurrent disturbance from flood irrigation and their interactions on the population dynamics of an important rodent pest, the Chinese striped hamster (Cricetulus barabensis), over 27 years in the croplands of the North China Plain. Strong density-dependent feedbacks occurred at both annual and seasonal scales. While warmer weather increased population sizes in nonbreeding seasons, this effect was counteracted by the negative effect of flood irrigation in breeding seasons. Precipitation showed significant positive effects in nonbreeding seasons, but negative effects in breeding seasons. There were important interactions between intrinsic dynamics, extrinsic dynamics and disturbance. Low temperature significantly increased the strength of density dependence in nonbreeding seasons, whereas intensification of flood irrigation area significantly increased the strength of density dependence but reduced the effect of summer precipitation in breeding seasons. Overall climate change is expected to increase population levels, but anthropogenic disturbance from flood irrigation will help prevent long-term population increases. The interactions between anthropogenic disturbance and both intrinsic and extrinsic (weather-driven) population dynamics caution that we need to consider anthropogenic disturbance as an integral component of population responses to climate change. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

  9. Protective effect of propolis on radiation-induced chromosomal damage on Chinese hamster ovary cells (CHO-K1)

    International Nuclear Information System (INIS)

    Spigoti, Geyza; Bartolini, Paolo; Okazaki, Kayo; Tsutsumi, Shiguetoshi

    2009-01-01

    In the last years, particular interest has been given to investigations concerning natural, effective and nontoxic compounds with radioprotective capacity in concert with increasing utilization of different types of ionizing radiation for various applications. Among them, propolis, a resinous mixture of substances collected by honey bees (Apis mellifera) has been considered promising since it presents several advantageous characteristics, i.e., antiinflammatory, anticarcinogenic, antimicrobial and free radical scavenging action. It is, therefore, a direct antioxidant that protects cells and organisms from the adverse effects of ionizing radiation. These relevant biological activities are mainly mediated by the flavonoids, present at relatively high concentrations in the propolis. Considering that the chemical composition and, consequently, the biological activity of propolis is variable according to the environmental plant ecology, the present study was conducted in order to evaluate the radioprotective capacity of Brazilian propolis, collected in the State of Rio Grande do Sul, against genotoxic damages induced by 60 Co γ-radiation in Chinese hamster ovary cells (CHO-K1). for this purpose, micronucleus induction was analyzed concerning irreparable damage, specifically related to DNA double-strand breaks, that are potentially carcinogenic. CHO-K1 cells were submitted to different concentrations of propolis (3 - 33 μg/ml), 1 h before irradiation, with 1 Gy of γ radiation (0.722 Gy/min). The data obtained showed a decreasing tendency in the quantity of radioinduced damage on cells previously treated with propolis. The radioprotective effect was more prominent at higher propolis concentration. The treatment with propolis alone did not induce genotoxic effects on CHO-K1 cells. Beside that, the treatment with propolis, associated or not with radiation, did not influence the kinetics of cellular proliferation. (author)

  10. Effects of D,L-buthionine-S,R-sulfoximine on cellular thiol levels and the oxygen effect in Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Astor, M.B.; Hall, E.J.; Biaglow, J.E.; Hartog, B.

    1984-01-01

    The role of glutathione (GSH) and total non-protein thiols (NPSH) in repairing radiation-induced free radical damage incurred under aerated and hypoxic conditions was investigated using Chinese hamster V79 cells cultured in vitro. GSH and NPSH levels were depleted in V79 cells of varying cell densities using the gamma-glutamyl-cysteine-synthetase inhibitor, D,L-Buthionine-S,R-sulfoximine (BSO). A small change in hypoxic cell radiosensitivity could be attributed to the loss of GSH while depletion of thiols to lower levels affected both aerated and hypoxic cell radiosensitivity, resulting in no change in the OER

  11. Interaction of neuromuscular blocking drugs with recombinant human m1–m5 muscarinic receptors expressed in Chinese hamster ovary cells

    OpenAIRE

    Cembala, T M; Sherwin, J D; Tidmarsh, M D; Appadu, B L; Lambert, D G

    1998-01-01

    Neuromuscular blocking drugs (NMBD's) are known to produce cardiovascular side effects manifesting as brady/tachycardias. In this study we have examined the interaction of a range of steroidal NMBD's with recombinant human m1–m5 muscarinic receptors expressed in Chinese hamster ovary cells. Our main hypothesis is that NMBD's may interact with m2 (cardiac) muscarinic receptors.All binding studies were performed with cell membranes prepared from CHO m1–m5 cells in 1 ml volumes of 20 mM HEPES, 1...

  12. Folk medicine Terminalia catappa and its major tannin component, punicalagin, are effective against bleomycin-induced genotoxicity in Chinese hamster ovary cells.

    Science.gov (United States)

    Chen, P S; Li, J H; Liu, T Y; Lin, T C

    2000-05-01

    Terminalia catappa L. is a popular folk medicine for preventing hepatoma and treating hepatitis in Taiwan. In this paper, we examined the protective effects of T. catappa leaf water extract (TCE) and its major tannin component, punicalagin, on bleomycin-induced genotoxicity in cultured Chinese hamster ovary cells. Pre-treatment with TCE or punicalagin prevented bleomycin-induced hgprt gene mutations and DNA strand breaks. TCE and punicalagin suppressed the generation of bleomycin-induced intracellular free radicals, identified as superoxides and hydrogen peroxides. The effectiveness of TCE and punicalagin against bleomycin-induced genotoxicity could be, at least in part, due to their antioxidative potentials.

  13. Interphase death of dividing cells. Death rate of cultured Chinese hamster fibroblasts as a function of ph inside and outside cells

    International Nuclear Information System (INIS)

    Veksler, A.M.; Kublik, L.N.; Ehjdus, L.Kh.

    1990-01-01

    In studying interphase death (ID) of dividing cells from Chinese hamster fibroblast culture a differently directed relationship between ID rate and pH has been shown: the ID rate increases with pH increasing from 6.6 to 8.1 and decreases with pH from 5.0 to 6.6. The dependence is the same as that observed with lymphoid cells. With radiation doses increasing from 100 to 600 Gy and pH defined, the ID rate increases

  14. Effects of 3-Deoxyadenosine (Cordycepin) on the repair of X-ray-induced DNA single- and double-strand breaks in chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Hiraoka, Wakako; Kuwabara, Mikinori; Sato, Fumiaki

    1990-01-01

    The ability of cordycepin to inhibit the repair of DNA strand breaks was examined with X-irradiated Chinese hamster V79 cells in log-phase culture. A filter elution technique revealed that 70 μM cordycepin did not inhibit the repair of single-strand breaks but inhibited the repair of double-strand breaks. These findings confirmed the fact that the increase in the lethality of cordycepin in X-irradiated cultured mammalian cells was attributable to unrepaired DNA double-strand breaks. (author)

  15. Ultraviolet light induction of diphtheria toxin-resistant mutations in normal and DNA repair-deficient human and Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Trosko, J.E.; Schultz, R.S.; Chang, C.C.; Glover, T.

    1980-01-01

    The role on unrepaired DNA lesions in the production of mutations is suspected of contributing to the initiation phase of carcinogenesis. Since the molecular basis of mutagenesis is not understood in eukaryotic cells, development of new genetic markers for quantitative in vitro measurement of mutations for mammalian cells is needed. Furthermore, mammalian cells, genetically deficient for various DNA repair enzymes, will be needed to study the role of unrepaired DNA lesions in mutagenesis. The results in this report relate to preliminary attempts to characterize the diphtheria toxin resistance marker as a useful quantitative genetic marker in human cells and to isolate and characterize various DNA repair-deficient Chinese hamster cells

  16. Sodium butyrate affects the cytotoxic and mutagenic response of V79 Chinese hamster cells to the genotoxic agents, daunorubicin and U.V. radiation

    International Nuclear Information System (INIS)

    Pani, B.; Babudri, N.; Giancotti, V.; Russo, E.

    1984-01-01

    It has been suggested that conditions which lead to modifications in the chromatin structure could be responsible for an increased accessibility of DNA to genotoxic agents in eukaryotic cells. With this in mind, the cytotoxic and mutagenic activity of the anthracycline antibiotic, daunorubicin, and of UV radiation was assayed on V79 Chinese hamster cells pretreated or not with 5 mM sodium butyrate, an agent known to induce modifications in the chromatin structure: this treatment in fact proved to induce the hyperacetylation of the core histones, and moreover to enhance the cytotoxic response of the cells to both daunorubicin and UV radiation and the mutagenic response to daunorubicin. (orig.)

  17. Enhanced efflux of [3H]vinblastine from Chinese hamster ovary cells transfected with a full-length complementary DNA clone for the mdr1 gene

    International Nuclear Information System (INIS)

    Hammond, J.R.; Johnstone, R.M.; Gros, P.

    1989-01-01

    Multidrug-resistant Chinese hamster ovary cell clones stably transfected with, and overexpressing, the mouse mdr1 complementary DNA clone along with drug-sensitive Chinese hamster ovary control cells were characterized for their capacities to accumulate and retain [ 3 H]vinblastine. Multidrug-resistant mdr1 transfectants show a 3-4-fold decrease in [ 3 H]vinblastine accumulation, compared to their drug-sensitive counterparts. After ATP depletion, this difference in [ 3 H]vinblastine accumulation between mdr1 transfectants and control cells effectively disappears. This ATP-dependent decreased drug accumulation is paralleled in mdr1 transfectants by an enhanced capacity of these cells to extrude the drug in an ATP-dependent manner. In medium containing glucose and glutamine, the mdr1 transfectants release preloaded drug at a rate five times that of control, drug-sensitive cells. In ATP-depleted control and mdr1-transfected cells, there is little difference in the rate or extent of [ 3 H]vinblastine release. The observation that the mdr1 transfectants show a decreased [ 3 H]vinblastine accumulation and an increased vinblastine release, both of which are abolished when cellular ATP levels are reduced, provides a direct demonstration that the product of the transfected mdr1 gene is responsible for a mechanism controlling cellular drug levels in an ATP-dependent manner. However, attempts to establish competition for [ 3 H]vinblastine transport by vincristine, daunomycin, and actinomycin D were only partly successful in mdr1 transfectants

  18. Kinetics of UV-induced changes in deoxynucleoside triphosphate pools in Chinese hamster ovary cells and their effect on measurements of DNA synthesis.

    Science.gov (United States)

    Newman, C N; Miller, J H

    1983-11-15

    Measurements of dNTP pools following exposure of Chinese hamster ovary cells to ultraviolet radiation reveals a rapid accumulation of cellular dTTP and a rapid loss of cellular dCTP. Exposure to 3-, 10- or 20 Jm-2 results in a 3-, 4- or 5.4-fold increase in cellular dTTP, respectively, within the first 10 min after exposure. dTTP levels then decrease noticeably, approaching the control value 3 to 5 hr later. In contrast, dCTP levels decrease rapidly within 10 min after exposure, ultimately to 1/10 that observed in the unirradiated control population. Recovery to normal dCTP levels is slow, taking in excess of 12 hr. No change in dATP is observed for 1-2 hr; subsequently, a moderate decrease in dATP levels occurs which is then followed by recovery, beginning 8 hr after irradiation. These results contrast with changes in dNTP pools observed in Chinese hamster V-79 cells exposed to mutagens. Measurements of rates of DNA synthesis by pulse-labeling cells with [3H]thymidine are also apparently affected by UV-induced transient deviations in the endogenous radiospecific activity of the labeled precursor.

  19. Establishment and Identification of Chinese Hamster Ovary Cell Lines with Stable Expression of Soluble CD40 Ligands

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    JIANG Hua-wei

    2014-09-01

    Full Text Available Objective: To establish the Chinese Hamster Ovary (CHO cell lines with stable expression of soluble CD40 ligands (sCD40L. Methods: Recombinant plasmid pIRES2-EGFP-sCD40L, enzyme digestion and sequencing identification were obtained by cloning sCD40L coding sequences into eukaryotic expression vector pIRES2-EGFP from carrier pDC316-sCD40 containing sCD40L. CHO cells were transfected by electroporation, followed by screening of resistant clones with G418, after which monoclones were obtained by limited dilution assay and multiply cultured. Flow cytometer and reverted fluorescence microscope were applied to observe the expression of green fluorescent protein, while sCD40L expression was detected by polymerase chain reaction (PCR, reverse transcription-polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA from aspects of deoxyribose nucleic acid (DNA, messenger ribonucleic acid (mRNA and protein, respectively. CHO-sCD40L was cultured together with MDA-MB-231 cells to compare the expression changes of surface molecule fatty acid synthase (Fas by flow cytometer and observe the apoptosis of MDA-MB-231 cells after Fas activated antibodies (CH-11 were added 24 h later. Results: Plasmid pIRES2-EGFP-sCD40L was successfully established, and cell lines with stable expression of sCD40L were obtained with cloned culture after CHO cell transfection, which was named as B11. Flow cytometer and reverted fluorescence microscope showed >90% expression of green fluorescent protein, while PCR, RT-PCR and ELISA suggested integration of sCD40L genes into cell genome DNA, transcription of sCD40L mRNA and sCD40L protein expression being (4.5±2.1 ng/mL in the supernatant of cell culture, respectively. After co-culture of B11 and MDA-MB-231 cells, the surface Fas expression of MDA-MB-231 cells was increased from (3±1.02 % to (34.8±8.75%, while the apoptosis rate 24 h after addition of CH11 from (5.4±1.32% to (20.7±5.24%, and the differences

  20. [Study on the cellular and humoral immunity effect of recombinant Chinese hamster ovary cell hepatitis B vaccine in adults].

    Science.gov (United States)

    Zhang, Wei; Han, Li-li; Lin, Chang-ying; Li, Li-qiu; Gao, Pei; Lin, Hui; Gong, Xiao-hong; Huang, Fang; Tang, Ya-qing; Ma, Jian-xin; Zhang, Hai-yan; Wang, Chen; Yang, Peng; Li, Hui; Wu, Jiang; Sun, Mei-ping; He, Xiong; Pang, Xing-huo

    2010-10-01

    To evaluate the cellular and humoral immunity effect of 10 µg and 20 µg recombinant Chinese hamster ovary (CHO) cell hepatitis B vaccine in adults by randomized double-blind controlled trials. A total of 642 adults aged 18 - 45 years old, non-vaccinated against hepatitis B, and hepatitis B five blood indicators negative were selected as the study subjects. The study subjects were randomly divided into two groups and each group had 321 subjects. The subjects were given 10 µg and 20 µg recombinant CHO hepatitis B vaccination respectively by 0, 1st, 6th month schedule. Blood sample was collected from each study subject one month after the second dose vaccination. The anti-HBs level was detected by Abbott chemiluminescence detection method (I2000) to evaluate humoral immunity status. Of all the study objects, 153 cases were randomly selected by the Excel random function. Their blood samples were collected and Lymphocyte were separated to detect the IL-4 and IFN-γ levels in vitro by enzyme-linked immunospot (ELISPOT) method to evaluate the cellular immunity status. The anti-HBs seroconversion rates in 10 µg and 20 µg dose group were 88.8% (285/321) and 95.3% (306/321) respectively, and 95%CI were 85.4% - 92.2% and 93.0% - 97.6% respectively. The spot forming cell (SFC) of IL-4 of the 20 µg-dose group (x(-) = 20.31) were significantly higher than the 10 µg-dose group (x(-) = 8.19, t = 3.27, P anti-HBs titer, the SFC of IL-4 also went up significantly. There was a positive correlation between SFC of IL-4 and anti-HBs (Spearman correlation coefficient = 0.538, P 0.05). The humoral and cellular immune effects of 20 µg recombinant CHO hepatitis B vaccine are better than that of the 10 µg recombinant CHO hepatitis B vaccine.20 µg recombinant CHO hepatitis B vaccine should be chosen as the adult's hepatitis B prevention vaccine.

  1. Yield of chromosomal aberrations and recoil particle range in Chineses hamster fibroblasts exposed to 8.5 to 500 keV neutrons

    International Nuclear Information System (INIS)

    Sturelid, S.; Bergman, R.

    1976-01-01

    Induction of chromatid aberrations in S-phase Chinese hamster fibroblasts has been studied for irradiation by 60 Co gamma rays and neutrons of average energy 8.5, 45, 83, 200 and 500 keV. At 10 per cent aberration level the relative biological afficiency varied between 2.2 +- 0.6 (at 8.5 keV) and a maximum of 47 +- 9 (at 200 keV). The neutron generated recoils have short range in comparison to chromosomal dimensions. The strong variation with neutron energy is therefore not necessarily reflecting variations in the average linear energy transfer. Good agreement between experimental and predicted response was obtained when effects ascribed to range were considered. A critical volume within which primary lesions should occur in order to make chromosomal aberrations probable was derived. The corresponding site radius was estimated to be 1-3 μm. (author)

  2. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-05

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Effects of 5 Thio-D-Glucose on cellular adenosine triphosphate levels and deoxyribonucleic acid rejoining in hypoxic and aerobic Chinese hamster cells

    International Nuclear Information System (INIS)

    Nagle, W.A.; Moss, A.J. Jr.; Roberts, H.G. Jr.; Baker, M.L.

    1980-01-01

    Intracellular adenosine triphosphate (ATP) levels were measured in both hypoxic and aerobic cultures of V79 Chinese hamster cells treated with 5-thio-D-glucose (5-SH-D-Glc). This glucose analog, a known inhibitor of D-glucose transport and metabolism, reduced ATP in cell cultures allowed to become hypoxic by cell metabolism, but not in aerobic cultures treated similarly. Cells depleted of ATP were unable to rejoin x-ray induced deoxyribonucleic acid (DNA) strand breaks as measured by the alkaline sucrose gradient sedimentation technique. The inference for radiation therapy is that inhibition of glucose metabolism selectively depletes energy reserves in hypoxic cells, rendering these cells more radiosensitive and leading to a more effective tumor treatment

  4. Enhancement of postreplication repair in ultraviolet-light-irradiated Chinese hamster cells by irradiation in G2 or s-phase

    International Nuclear Information System (INIS)

    D'Ambrosio, S.M.; Aebersold, P.M.; Setlow, R.B.

    1978-01-01

    Postreplication repair in synchronous Chinese hamster cells was determined after split doses of ultraviolet (uv) radiation. Repair was enhanced by irradiation of cells in G 2 or S-phase with a small dose of uv radiation at least 1.5 h before a three-fold larger dose of uv. There was significantly greater enhancement when the first dose was given in G 2 than when it was given in the S-phase 0.5 to 1.5 h before the test dose. These data indicate that enhancement of postreplication repair does not require active DNA replication and qualitatively is independent of when in the cell cycle the cells are irradiated

  5. In vivo mutagenicity studies in rats mice and Chinese hamsters fed irradiated foodstuffs - chicken, fish, dates, pulses, mangoes and cocoa beans

    International Nuclear Information System (INIS)

    Renner, H.W.

    1982-01-01

    Three in vivo genetic toxicity tests were performed in rats, mice and Chinese hamsters to detect possible mutagenic effects of irradiated chicken, dried dates, fish, cocoa beans, pulses and mangoes. The tests employed were the micronucleus test and sister-chromatid exchange (SCE) test for irradiated and unirradiated samples of all foodstuffs listed, and the spermatogonia test, (including SCE technique) in mice for irradiated and unirradiated chicken, fish and dates only. In the case of cocoa beans, the mutagenicity tests were performed on an additional test group fed beans fumigated with ethylene oxide. The different mammalian species used for the various experiments are given below. None of the tests provided any evidence of mutagenicity induced by irradiation in any of the foodstuffs studied. Moreover, these tests are currently considered to be the most sensitive in vivo mutagenicity tests in mammals. (orig.)

  6. Induction and removal of DNA interstrand cross-links in V-79 Chinese hamster cells measured by hydroxylapatite chromatography after treatments with bifunctional furocoumarins

    International Nuclear Information System (INIS)

    Dardalhon, M.; Averbeck, D.

    1988-01-01

    DNA interstrand crosslinks (CL) photoinduced by bifunctional furocoumarins in V-79 Chinese hamster cells were measured by alkaline denaturation and hydroxylapatite chromatography. Treatments with 5-methoxypsoralen (5-MOP), 8-methoxypsoralen (8-MOP) and 4,5',8-trimethylpsoralen (4,5',8-TMP) and 365 nm irradiation (UVA) confer a dose-dependent linear increase in the amount of double-stranded DNA indicating the induction of CL. Determination in alkaline sucrose gradients of the molecular weight of the DNA and estimation of drug-induced strand breakage allowed quantification of the CL induced. 5-MOP was found to be slightly more effective than 8-MOP whereas 4,5',8-TMP was 9 times more effective for the induction of CL. The fate of CL during post-treatment incubation was also followed. Cells in exponential growth phase were found to be efficient in the removal of CL. (Author)

  7. Gamma-ray induced DNA breaks and repair studied by immuno-labelling of poly(ADP-ribose) polymerase (PARP) in chinese hamster ovary cells (CHO)

    International Nuclear Information System (INIS)

    Bidon, N.; Noel, G.; Averbeck, D.; Varlet, P.; Salamero, J.; DeMurcia, G.

    1998-01-01

    The poly(ADP-ribose)polymerase is a nuclear ubiquitous enzyme capable of binding to DNA breaks. Chinese hamster ovary cells were (CHO-K1) cultured on slides and γ-irradiated ( 137 Cs) at a high (12.8 Gy/min) or medium dose rate (5 Gy/min), and immuno-labelling against (ADP-ribose) polymers immediately or three hours after irradiation. Quantification and localisation of γ-ray induced breaks was performed by confocal microscopy. The results show a dose effect relationship, a dose-rate effect and the signal disappearance after 3 hours at 37 deg.C. The presence of PARP activity appears to reflect γ-rays induced DNA fragmentation. (authors)

  8. Correlation between the lipophilicity of substituted phenols and their inhibition of the Na+/K+-ATPase of Chinese hamster ovary cells.

    Science.gov (United States)

    Cascorbi, I; Ahlers, J

    1989-10-02

    The Na+/K+-ATPase of Chinese Hamster Ovary (CHO) cells, a plasma membrane bound protein was used as a test system to evaluate the toxicity of several phenol derivatives on membranes. Taking only 2 physico-chemical parameters into consideration, viz., the logarithm of the octanol/water partition coefficient as an indicator for the lipophilicity and the sigma-Hammett constant as a measure for the polarity of the phenol substitutes, it was possible to predict the toxicity with high significance. A multivariate regression analysis calculated a correlation coefficient of 0.99. The results confirm studies performed in our laboratory on cytotoxicity and on functional membrane proteins of fungal and mammalian cells [1,2], suggesting a common mechanism of toxicity by the action of hydrophobic xenobiotics on biomembranes. Taking into account the different sensitivities of the test systems, Quantitative Structure-Activity Relationship (QSAR) analyses could help to explain the basic toxicity of several classes of environmental chemicals.

  9. Perturbation of N-linked oligosaccharide structure results in an altered incorporation of [3H]palmitate into specific proteins in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Wellner, R.B.; Ghosh, P.C.; Roecklein, B.; Wu, H.C.

    1987-01-01

    Increased [ 3 H]palmitate incorporation into specific cellular proteins has been reported to occur in Chinese hamster ovary and yeast mutant cells. In this paper we report studies concerning the relationship between N-linked oligosaccharide structure and [ 3 H]palmitate incorporation into proteins of Chinese hamster ovary (CHO) cells. We have compared the incorporation of [ 3 H]palmitate into proteins of wild-type and four different mutant CHO cell lines defective in various steps of N-linked protein glycosylation. Sodium dodecyl sulfate-gel electrophoretic analysis showed that three of the mutants exhibited increased [ 3 H]palmitate incorporation into several CHO cellular proteins (approximately 30,000-38,000 molecular weight) as compared to the wild-type cells. One of the affected mutants which accumulates the Man5Gn2Asn intermediate structure was examined in detail. In agreement with earlier reports, virtually all of the [ 3 H] palmitate-labeled proteins of both wild-type and mutant cell lines are membrane-bound. Pretreatment of the mutant cell line with tunicamycin blocked the increased [ 3 H]palmitate incorporation into the two specific proteins (both of approximately 30,000 molecular weight) observed in untreated cells; the decreased incorporation of [ 3 H]palmitate into the 30,000 molecular weight species was accompanied by a concomitant increase in the incorporation of [ 3 H]palmitate into two proteins of approximately 20,000 molecular weight. Pretreatment of wild-type cells with tunicamycin also caused increased [ 3 H]palmitate incorporation into the 20,000 molecular weight species

  10. Use of the α-mannosidase I inhibitor kifunensine allows the crystallization of apo CTLA-4 homodimer produced in long-term cultures of Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Yu, Chao; Crispin, Max; Sonnen, Andreas F.-P.; Harvey, David J.; Chang, Veronica T.; Evans, Edward J.; Scanlan, Christopher N.; Stuart, David I.; Gilbert, Robert J. C.; Davis, Simon J.

    2011-01-01

    The α-mannosidase I inhibitor kifunensine inhibited N-glycan processing in long-term cultures of Chinese hamster ovary cells, allowing deglycosylation and crystallization of the homodimeric extracellular region of the inhibitory glycoprotein receptor CTLA-4 (CD152). Glycoproteins present problems for structural analysis since they often have to be glycosylated in order to fold correctly and because their chemical and conformational heterogeneity generally inhibits crystallization. It is shown that the α-mannosidase I inhibitor kifunensine, which has previously been used for the purpose of glycoprotein crystallization in short-term (3–5 d) cultures, is apparently stable enough to be used to produce highly endoglycosidase H-sensitive glycoprotein in long-term (3–4 week) cultures of stably transfected Chinese hamster ovary (CHO) cells. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based analysis of the extracellular region of the cytotoxic T-lymphocyte antigen 4 (CTLA-4; CD152) homodimer expressed in long-term CHO cell cultures in the presence of kifunensine revealed that the inhibitor restricted CTLA-4 glycan processing to Man 9 GlcNAc 2 and Man 5 GlcNAc 2 structures. Complex-type glycans were undetectable, suggesting that the inhibitor was active for the entire duration of the cultures. Endoglycosidase treatment of the homodimer yielded protein that readily formed orthorhombic crystals with unit-cell parameters a = 43.9, b = 51.5, c = 102.9 Å and space group P2 1 2 1 2 1 that diffracted to Bragg spacings of 1.8 Å. The results indicate that kifunensine will be effective in most, if not all, transient and long-term mammalian cell-based expression systems

  11. Species differences in the immunoreactive expression of oxytocin, vasopressin, tyrosine hydroxylase and estrogen receptor alpha in the brain of Mongolian gerbils (Meriones unguiculatus and Chinese striped hamsters (Cricetulus barabensis.

    Directory of Open Access Journals (Sweden)

    Yu Wang

    Full Text Available Species differences in neurochemical expression and activity in the brain may play an important role in species-specific patterns of social behavior. In the present study, we used immunoreactive (ir labeling to compare the regional density of cells containing oxytocin (OT, vasopressin (AVP, tyrosine hydroxylase (TH, or estrogen receptor alpha (ERα staining in the brains of social Mongolian gerbils (Meriones unguiculatus and solitary Chinese striped hamsters (Cricetulus barabensis. Multiple region- and neurochemical-specific species differences were found. In the anterior hypothalamus (AH, Mongolian gerbils had higher densities of AVP-ir and ERα-ir cells than Chinese striped hamsters. In the lateral hypothalamus (LH, Mongolian gerbils also had higher densities of AVP-ir and TH-ir cells, but a lower density of OT-ir cells, than Chinese striped hamsters. Furthermore, in the anterior nucleus of the medial preoptic area (MPOAa, Mongolian gerbils had higher densities of OT-ir and AVP-ir cells than Chinese striped hamsters, and an opposite pattern was found in the posterior nucleus of the MPOA (MPOAp. Some sex differences were also observed. Females of both species had higher densities of TH-ir cells in the MPOAa and of OT-ir cells in the intermediate nucleus of the MPOA (MPOAi than males. Given the role of these neurochemicals in social behaviors, our data provide additional evidence to support the notion that species-specific patterns of neurochemical expression in the brain may be involved in species differences in social behaviors associated with different life strategies.

  12. The replication timing program of the Chinese hamster β-globin locus is established coincident with its repositioning near peripheral heterochromatin in early G1 phase

    Science.gov (United States)

    Li, Feng; Chen, Jianhua; Izumi, Masako; Butler, Mark C.; Keezer, Susan M.; Gilbert, David M.

    2001-01-01

    We have examined the dynamics of nuclear repositioning and the establishment of a replication timing program for the actively transcribed dihydrofolate reductase (DHFR) locus and the silent β-globin gene locus in Chinese hamster ovary cells. The DHFR locus was internally localized and replicated early, whereas the β-globin locus was localized adjacent to the nuclear periphery and replicated during the middle of S phase, coincident with replication of peripheral heterochromatin. Nuclei were prepared from cells synchronized at various times during early G1 phase and stimulated to enter S phase by introduction into Xenopus egg extracts, and the timing of DHFR and β-globin replication was evaluated in vitro. With nuclei isolated 1 h after mitosis, neither locus was preferentially replicated before the other. However, with nuclei isolated 2 or 3 h after mitosis, there was a strong preference for replication of DHFR before β-globin. Measurements of the distance of DHFR and β-globin to the nuclear periphery revealed that the repositioning of the β-globin locus adjacent to peripheral heterochromatin also took place between 1 and 2 h after mitosis. These results suggest that the CHO β-globin locus acquires the replication timing program of peripheral heterochromatin upon association with the peripheral subnuclear compartment during early G1 phase. PMID:11470818

  13. Enhanced production of recombinant proteins by a small molecule protein synthesis enhancer in combination with an antioxidant in recombinant Chinese hamster ovary cells.

    Science.gov (United States)

    Camire, Joseph; Kim, Dongjoo; Kwon, Soonjo

    2017-07-01

    The improvement in the production of recombinant proteins has been linked in a number of small molecules such as carboxylic acids to the inhibition of histone deacetylase, leading to increased transcription of genes. However, carboxylic acids such as pentanoic acid and butanoic acid have been shown to promote an apoptotic response in Chinese hamster ovary (CHO) cell culture. Supplementation of cultures with antioxidants has shown the ability to reduce the apoptotic response of carboxylic acid supplementation, leading to increased therapeutic protein production. In this study, we showed that pentanoic acid reduced the number of cells entering early apoptosis relative to butanoic acid by 15.4%. Additionally, supplementation of butanoic acid- and pentanoic acid-treated cultures with N-acetyl cysteine (NAC) reduced the population of cells entering early apoptosis by 5.3 and 10.0%, respectively, while increasing productivity by 19.5% in the presence of pentanoic acid and NAC. Conversely, a decrease of 5.7% in production was observed in response to combined butanoic acid and N-acetyl cysteine treatment. The results presented herein provide evidence that a culture supplementation method is critical for optimization of biopharmaceutical manufacturing processes.

  14. DNA sequence analysis of methylene chloride-induced HPRT mutations in Chinese hamster ovary cells: comparison with the mutation spectrum obtained for 1,2-dibromoethane and formaldehyde.

    Science.gov (United States)

    Graves, R J; Trueman, P; Jones, S; Green, T

    1996-05-01

    Glutathione-S-transferase-mediated metabolism of methylene chloride (MC) generates S-chloromethylglutathione, which has the potential to react with DNA, and formaldehyde, which is a known mutagen. MC-induced mutations in the HPRT gene of Chinese hamster ovary cells have been sequenced and compared with the mutations induced by 1, 2-dibromoethane (1,2-DEB), which is known to act through a glutathione conjugate, and formaldehyde. All three compounds induced primarily point mutations, with a small number of insertion and deletion events. The most common point mutations induced by MC were GC-->AT transitions (4/8), with two GC-->CG transversions and two AT-->TA transversions. This pattern of mutations showed greater similarity with 1,2-DBE, where the dominant point mutations were GC-->AT transitions (7/9), than formaldehyde, where all mutations were single base transversions and 5/6 occurred from AT base pairs. The mutation sequence results for MC suggest that S-chloromethylglutathione plays a major role in MC mutagenesis, with only a limited contribution from formaldehyde. The involvement of a glutathione (GSH) conjugate in MC mutagenicity would be analogous to the well-characterized pathway of activation of 1,2-DBE.

  15. Evaluation of two public genome references for chinese hamster ovary cells in the context of rna-seq based gene expression analysis.

    Science.gov (United States)

    Chen, Chun; Le, Huong; Goudar, Chetan T

    2017-07-01

    RNA-Seq is a powerful transcriptomics tool for mammalian cell culture process development. Successful RNA-Seq data analysis requires a high quality reference for read mapping and gene expression quantification. Currently, there are two public genome references for Chinese hamster ovary (CHO) cells, the predominant mammalian cell line in the biopharmaceutical industry. In this study, we compared these two references by analyzing 60 RNA-Seq samples from a variety of CHO cell culture conditions. Among the 20,891 common genes in both references, we observed that 31.5% have more than 7.1% quantification differences, implying gene definition differences in the two references. We propose a framework to quantify this difference using two metrics, Consistency and Stringency, which account for the average quantification difference between the two references over all samples, and the sample-specific effect on the quantification result, respectively. These two metrics can be used to identify potential genes for future gene model improvement and to understand the reliability of differentially expressed genes identified by RNA-Seq data analysis. Before a more comprehensive genome reference for CHO cells emerges, the strategy proposed in this study can enable more robust transcriptome analysis from CHO cell RNA-Seq data. Biotechnol. Bioeng. 2017;114: 1603-1613. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  16. Generation of high-producing cell lines by overexpression of cell division cycle 25 homolog A in Chinese hamster ovary cells.

    Science.gov (United States)

    Lee, Kyoung Ho; Tsutsui, Tomomi; Honda, Kohsuke; Asano, Ryutaro; Kumagai, Izumi; Ohtake, Hisao; Omasa, Takeshi

    2013-12-01

    To improve the efficiency of conventional gene amplification systems, the effect of cell cycle modification during the gene amplification process on IgG production was investigated in Chinese hamster ovary (CHO) cells. The full-length cDNA of CHO cell division cycle 25 homolog A (Cdc25A) was introduced into CHO DG44 cells and the effects of CDC25A overexpression on the cell cycle, transgene copy number and IgG productivity were examined. Both wild-type and mutated CDC25A-overexpressing CHO cells showed a rapid increase in transgene copy number compared with mock cells during the gene amplification process, in both cell pools and individual clones. High-producing clones were obtained with high frequency in CDC25A-overexpressing cell pools. The specific production rate of the isolated clone CHO SD-S23 was up to 2.9-fold higher than that of mock cells in the presence of 250 nM methotrexate (MTX). Cell cycle analysis revealed that the G2 to M phase transition rate was increased ∼1.5-fold in CDC25A-overexpressing CHO cells under MTX treatment. Our results show the improvement of conventional gene amplification systems via cell cycle engineering at an early stage of cell line development. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Effects of Melophlins on Colony Formation of Chinese Hamster V79 Cells and IL-8 Production in PMA-stimulated HL-60 Cells

    Directory of Open Access Journals (Sweden)

    Michio Namikoshi

    2007-01-01

    Full Text Available We have recently isolated four new melophlins P (1, Q (2, R (3, and S (4 together with seven known melophlins A (5, D (6, E (7, G (8, H (9, I (10, and O (11 from two marine sponges of the genus Melophlus collected in Palau. In this study, the influence of these compounds on the colony formation of Chinese hamster V79 cells and the production of IL-8 in PMA-stimulated HL-60 cells were examined. These 11 compounds did not show any effect on IL-8 production. The EC50 values of compounds 2, 3, 4, 5, 7, 9, 10, and 11 against V79 cells were 44.0, 13.3, 16.7, 27.2, 19.8, 8.5, 23.1, and 9.6 μM, respectively. The linear-chain-type compounds (1, 6, and 8 were not active against V79 cells at 50 μM. Although the growth inhibitory activity of these melophlins was not remarkable, some structure-activity relationships of these compounds against V79 and murine leukemia L1210 cells were observed.

  18. A uv-sensitive Chinese hamster lung fibroblast cell line (V79/UC) with a possible defect in DNA polymerase activity is deficient in DNA repair

    International Nuclear Information System (INIS)

    Creissen, D.M.; Hill, C.K.

    1991-01-01

    Studies of repair enzyme activities in a uv-sensitive cell line (V79/UC) derived from Chinese hamster V79 cells have revealed levels of total DNA polymerase that are about 50% of the levels in the parental cell line. There are a number of DNA polymerase inhibitors available which allow us to distinguish between the major forms of DNA polymerase (alpha, beta, gamma, and delta) identified in mammalian cells. Enzyme assays with these inhibitors indicate that the aphidicolin-sensitive DNA polymerase is defective in the V79/UC cell line. This could be either polymerase alpha or delta, or both. The V79/UC cells do not express resistance to aphidicolin in standard toxicity studies. However, when aphidicolin is added postirradiation in survival assays designed to measure the extent of inhibitable repair, V79/UC cells do not respond with the further decrease in survival seen in the parental line. Further evidence of a polymerase-dependent repair defect is evident from alkaline elution data. In this case the V79/UC cells show the appearance of single-strand breaks following uv irradiation in the absence of any added inhibitor. Cells of the V79/M12G parental line, on the other hand, show the appearance of single-strand breaks only when aphidicolin is present

  19. The effect of defective DNA double-strand break repair on mutations and chromosome aberrations in the Chinese hamster cell mutant XR-V15B

    International Nuclear Information System (INIS)

    Helbig, R.; Speit, G.; Zdzienicka, M.Z.

    1995-01-01

    The radiosensitive Chinese hamster cell line XR-V15B was used to study the effect of decreased rejoining of DNA double-strand breaks (DSBs) on gene mutations and chromosome aberrations. XR-V15B cells are hypersensitive to the cytotoxic effects of neocarzinostatin (NCS) and methyl methanesulfonate (MMS). Both mutagens induced more chromosome aberrations in XR-V15B cells than in the parental cell strain. The clastogenic action of NCS was characterized by the induction of predominantly chromosome-type aberrations in cells of both strains, whereas MMS induced mainly chromatid aberrations. The frequency of induced gene mutations at the hprt locus was not increased compared to the parental V79 cells when considering the same survival level. Molecular analysis by multiplex polymerase chain reaction (PCR) of mutants induced by NCS revealed a high frequency of deletions in cells of both cell lines. Methyl methane-sulfonate induced mainly mutations without visible change in the PCR pattern, which probably represent point mutations. Our findings suggest a link between a defect in DNA DSB repair and increased cytotoxic and clastogenic effects. However, a decreased ability to rejoin DNA DSBs does not seem to influence the incidence and types of gene mutations at the hprt locus induced by NCS and MMS. 28 refs., 4 figs., 3 tabs

  20. Accelerated homology-directed targeted integration of transgenes in Chinese hamster ovary cells via CRISPR/Cas9 and fluorescent enrichment.

    Science.gov (United States)

    Lee, Jae Seong; Grav, Lise Marie; Pedersen, Lasse Ebdrup; Lee, Gyun Min; Kildegaard, Helene Faustrup

    2016-11-01

    Targeted gene integration into site-specific loci can be achieved in Chinese hamster ovary (CHO) cells via CRISPR/Cas9 genome editing technology and the homology-directed repair (HDR) pathway. The low efficiency of HDR often requires antibiotic selection, which limits targeted integration of multiple genes at multiple sites. To improve HDR-mediated targeted integration, while avoiding the use of selection markers, chemical treatment for increased HDR, and fluorescent enrichment of genome-edited cells was assessed in CHO cells. Chemical treatment did not improve HDR-mediated targeted integration. In contrast, fluorescent markers in Cas9 and donor constructs enable FACS enrichment, resulting in a threefold increase in the number of cells with HDR-mediated genome editing. Combined with this enrichment method, large transgenes encoding model proteins (including an antibody) were successfully targeted integrated. This approach provides a simple and fast strategy for targeted generation of stable CHO production cell lines in a rational way. Biotechnol. Bioeng. 2016;113: 2518-2523. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Evidence for the induction of two types of potentially lethal damage after exposure of plateau phase Chinese hamster V79 cells to γ-rays

    International Nuclear Information System (INIS)

    Iliakis, G.

    1985-01-01

    The fixation of γ-rays induced potentially damage (PLD) caused after treatment either with β-araA or in medium made hypertonic by the addition of sodium chloride was studied in plateauphase chinese hamster V79 cells. Treatment with β-araA was found to affect a sector of PLD, the fixation of which specifically reduced the shoulder width of the survival curve. The effect was maximized when cell survival reached levels corresponding to an exponential line, with a slope similar to the final slope of the survival curve of untreated cells. This effect was achieved by a four hour treatment with β-araA at concentrations above 150 μM. Longer treatment times or incubation at higher β-araA concentrations did not significantly enhance the effect. Treatment in hypertonic medium, on the other hand, enhanced cell killing in a concentration dependent (NaCl-concentration) way and the survival reached values much lower than those corresponding to an exponential line. No indication for a plateau in the effect, indicating complete fixation of the sector of PLD that reacts sensitively to this treatment, was obtained. Boht the slope and the shoulder width of the survival curve were affected, the slope first being increaseed after short treatment times (up to 10 min), followed by a decrease in the shoulder width after longer treatment times (longer than 10 min). (orig./WL)

  2. Expression of difficult-to-remove host cell protein impurities during extended Chinese hamster ovary cell culture and their impact on continuous bioprocessing.

    Science.gov (United States)

    Valente, Kristin N; Lenhoff, Abraham M; Lee, Kelvin H

    2015-06-01

    During biopharmaceutical manufacturing, Chinese hamster ovary (CHO) cells produce hundreds of extracellular host cell protein (HCP) impurities, which must be removed from the therapeutic product by downstream purification operations to ensure patient safety. A subset of 118 of these HCPs have been reported as exceptionally difficult to remove during downstream purification because they co-purify due to retention characteristics on chromatographic media and/or product-association through strongly attractive interactions to the therapeutic protein. As the biopharmaceutical industry moves towards continuous bioprocessing, it is important to consider the impact of extended culture of CHO cells on the expression of extracellular HCP impurities, especially those HCPs known to challenge downstream purification. Two complementary proteomic techniques, two-dimensional electrophoresis (2DE) and shotgun, were applied to detect variations in the extracellular CHO HCP profile over 500 days of culture. In total, 92 HCPs exhibited up to 48-fold changes in expression, with 34 of these HCPs previously reported as difficult to purify. Each proteomic technique detected differential expression by a distinct set of HCPs, with 10 proteins exhibiting significant variable expression by both methods. This study presents the impact of cell age on the extracellular CHO HCP impurity profile and identifies HCPs with variable expression levels, which warrant further investigation to facilitate their clearance in downstream purification. © 2014 Wiley Periodicals, Inc.

  3. Efficient expression of stable recombinant human insulin-like growth factor-1 fusion with human serum albumin in Chinese hamster ovary cells.

    Science.gov (United States)

    Wan, Aini; Xu, Dongsheng; Liu, Kedong; Peng, Lin; Cai, Yanfei; Chen, Yun; He, Yang; Yang, Jianfeng; Jin, Jian; Li, Huazhong

    2017-08-09

    Insulin-like growth factor-1 (IGF-1) plays a crucial role in cell development, differentiation, and metabolism, and has been a potential therapeutic agent for many diseases. Chinese hamster ovary (CHO) cells are widely used for production of recombinant therapeutic proteins, but the expression level of IGF-1 in CHO cells is very low (1,500 µg/L) and the half-life of IGF-1 in blood circulation is only 4.5 min according to previous studies. Therefore, IGF-1 was fused to long-circulating serum protein human serum albumin (HSA) and expressed in CHO cells. After 8-day fed-batch culture, the expression level of HSA-IGF-1 reached 100 mg/L. The fusion protein HSA-IGF-1 was purified with a recovery of 35% using a two-step chromatographic procedure. According to bioactivity assay, the purified HSA-IGF-1 could stimulate the proliferation of NIH3T3 cells in a dose-dependent fashion and promote the cell-cycle progression. Besides this, HSA-IGF-1 could bind to IGF-1 receptor on cell membrane and activate the intracellular PI3K/AKT signaling pathway. Our study suggested that HSA fusion technology carried out in CHO cells not only provided bioactivity in HSA-IGF-1 for further research but also offered a beneficial strategy to produce other similar cytokines in CHO cells.

  4. Improved gene amplification by cell-cycle engineering combined with the Cre-loxP system in Chinese hamster ovary cells.

    Science.gov (United States)

    Matsuyama, Rima; Tsutsui, Tomomi; Lee, Kyoung Ho; Onitsuka, Masayoshi; Omasa, Takeshi

    2015-12-01

    The dihydrofolate reductase gene amplification system is widely used in Chinese hamster ovary (CHO) cells for the industrial production of therapeutic proteins. To enhance the efficiency of conventional gene amplification systems, we previously presented a novel method using cell-cycle checkpoint engineering. Here, we constructed high-producing and stable cells by the conditional expression of mutant cell division cycle 25 homolog B (CDC25B) using the Cre-loxP system. A bispecific antibody-producing CHO DG44-derived cell line was transfected with floxed mutant CDC25B. After inducing gene amplification in the presence of 250 nM methotrexate, mutant CDC25B sequence was removed by Cre recombinase protein expression. Overexpression of the floxed mutant CDC25B significantly enhanced the efficiency of transgene amplification and productivity. Moreover, the specific production rate of the isolated clone CHO Cre-1 and Cre-2 were approximately 11-fold and 15-fold higher than that of mock-transfected clone CHO Mock-S. Chromosomal aneuploidy was increased by mutant CDC25B overexpression, but Cre-1 and Cre-2 did not show any changes in chromosome number during long-term cultivation, as is the case with CHO Mock-S. Our results suggest that high-producing and stable cells can be constructed by conditionally controlling a cell-cycle checkpoint integrated in conventional gene amplification systems. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. An inhibitor of potentially lethal damage (PLD) repair reduces the frequency of γ-ray mutations in cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Yokoiyama, A.; Kada, T.; Kuroda, Y.

    1992-01-01

    Cordycepin (3'-deoxyadenosine, 3 - dA) is an RNA antimetabolite and a radiosensitizer in cultured mammalian cells. In the present paper, the effects of 3'-dA on γ-ray-induced lethality and 6-thioguanine (6TG)-resistant mutations in cultured Chinese hamster V79 cells were examined. 3'-dA had the effect of sensitizing the lethality induced by γ-rays. The potentially lethal damage (PLD) repair produced by post-incubation cells in Hanks' solution after γ-irradiation was almost completely suppressed by 5x10 -5 M 3'-dA. When cells were irradiated with 10 Gy γ-rays and incubated with 3'-dA for 5 h, the frequency of 6TG-resistant mutations induced by γ-rays decreased to 1/6 of that of the irradiated cells incubated without 3'-dA. The decrease in the frequency of γ-ray-induced mutations was dependent on the length of incubation time with 3'-dA. It is suggested that the inhibition of PLD repair by 3'-dA may be that of error-prone repair. (author). 26 refs.; 5 figs

  6. Cell survival after the combined action of manganese (MnCl2) and X-rays in synchronized Chinese hamster cells

    International Nuclear Information System (INIS)

    Skreb, Y.; Nagy, B.

    1984-01-01

    The interactions between the effects of manganese chloride and X-rays were studied in synchronized populations of V79 Chinese hamster fibroblasts. The cells were selected by shaking off asynchronous cultures for detachment of mitotic cells which were plated in petri dishes and exposed to various treatments. Irradiation was carried out with a Philips RT-100 X-ray unit. A final concentration of 0.25 mM MnCl 2 was used. The main parameter was the colony forming ability of the surviving cell fraction. When MnCl 2 was administered over 1 h, its toxicity was low regardless of the phase of the cell cycle. Administered separately, 2 Gy irradiation produced only a slight decrease in survival, less marked in the S phase. However, the two agents together induced a synergistic inhibition of the surviving fraction in the S phase when the metal was given immediately after irradiation. If manganese wad administered 3 h after irradiation the two inhibitory effects apparently remained only additive. It seems that MnCl 2 can impair some repair processes starting immediately after irradiation. (orig.)

  7. Anthracyclines as radiosensitizers. A Cu(II) complex of a simpler analogue modifies DNA in Chinese Hamster V79 cells under low-dose γ radiation

    International Nuclear Information System (INIS)

    Saurabh Das; Mandal, P.C.

    2014-01-01

    Hydroxy-9,10-anthraquinones are structural analogues of anthracycline anticancer drugs showing similarity in physicochemical attributes, electrochemical behavior and biophysical interactions. 1,2-dihydroxy-9,10-anthraquinone (Q) and its complexes with Cu(II)/Ni(II) were studied for γ radiation induced modification of DNA in Chinese Hamster V79 cells. The amount of double stranded DNA remaining was ascertained by fluorometric analysis of DNA unwinding using ethidium bromide. Modification of double stranded DNA increased in the presence of Q and Cu(II)-Q when cells were irradiated (0-4.2 Gray). Ni(II)-Q was not that effective. Changing incubation time before recovery of DNA from cells there was evidence for DNA repair that was least for Cu(II)-Q treated cells. Minimum repair in case of Cu(II)-Q treated cells suggest the compound either assists radiation induced damage of agents responsible for repair or interacts with species like H 2 O 2 that assist in repair. Since a hydroxy-9,10-anthraquinone and its Cu(II) complex show radiosensitizing property, anthracyclines that contain a hydroxy-9,10-anthraquinone as the core moiety could also be tried as radiosensitizers in treating cancer. (author)

  8. Species comparison of liver cancers induced by internally deposited /sup 144/Ce or /sup 239/Pu in dogs and Chinese hamsters

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Brooks, A.L.; Hahn, F.F.; Boecker, B.B.; McClellan, R.O.

    1984-01-01

    The risk of liver cancer from alpha-emitting radionuclides has been estimated for people from studies of patients injected with Thorotrast, which contains an alpha-emitting radionuclide. There is no corresponding estimation of the risk of liver cancers in people from internally-deposited beta-emitting radionuclides because of the lack of human data. Life-span studies in Beagle dogs exposed by inhalation to /sup 144/CeCl/sub 3/, a beta-emitting radionuclide, or by injection to /sup 239/Pu citrate, an alpha-emitting radionuclide, and in Chinese hamsters exposed by intravenous injections to /sup 144/Ce-/sup 144/Pr citrate or /sup 239/Pu citrate have provided information on liver cancers in these species. These radionuclides accumulated in the liver resulting in significant radiation exposure of the liver. Liver cancer occurred long after exposure. When the lifetime risks of liver cancer were calculated, /sup 239/Pu was found to be more effective than /sup 144/Ce in inducing liver cancers by factor of 10 to 12. The risk of liver cancer from internally-deposited beta emitters for people are estimated by assuming this relationship for people

  9. Sustained productivity in recombinant Chinese Hamster Ovary (CHO) cell lines: proteome analysis of the molecular basis for a process-related phenotype

    LENUS (Irish Health Repository)

    Meleady, Paula

    2011-07-24

    Abstract Background The ability of mammalian cell lines to sustain cell specific productivity (Qp) over the full duration of bioprocess culture is a highly desirable phenotype, but the molecular basis for sustainable productivity has not been previously investigated in detail. In order to identify proteins that may be associated with a sustained productivity phenotype, we have conducted a proteomic profiling analysis of two matched pairs of monoclonal antibody-producing Chinese hamster ovary (CHO) cell lines that differ in their ability to sustain productivity over a 10 day fed-batch culture. Results Proteomic profiling of inherent differences between the two sets of comparators using 2D-DIGE (Difference Gel Electrophoresis) and LC-MS\\/MS resulted in the identification of 89 distinct differentially expressed proteins. Overlap comparisons between the two sets of cell line pairs identified 12 proteins (AKRIB8, ANXA1, ANXA4, EIF3I, G6PD, HSPA8, HSP90B1, HSPD1, NUDC, PGAM1, RUVBL1 and CNN3) that were differentially expressed in the same direction. Conclusion These proteins may have an important role in sustaining high productivity of recombinant protein over the duration of a fed-batch bioprocess culture. It is possible that many of these proteins could be useful for future approaches to successfully manipulate or engineer CHO cells in order to sustain productivity of recombinant protein.

  10. Alpha 2-adrenergic receptor stimulation of phospholipase A2 and of adenylate cyclase in transfected Chinese hamster ovary cells is mediated by different mechanisms

    International Nuclear Information System (INIS)

    Jones, S.B.; Halenda, S.P.; Bylund, D.B.

    1991-01-01

    The effect of alpha 2-adrenergic receptor activation on adenylate cyclase activity in Chinese hamster ovary cells stably transfected with the alpha 2A-adrenergic receptor gene is biphasic. At lower concentrations of epinephrine forskolin-stimulated cyclic AMP production is inhibited, but at higher concentrations the inhibition is reversed. Both of these effects are blocked by the alpha 2 antagonist yohimbine but not by the alpha 1 antagonist prazosin. Pretreatment with pertussis toxin attenuates inhibition at lower concentrations of epinephrine and greatly potentiates forskolin-stimulated cyclic AMP production at higher concentrations of epinephrine. alpha 2-Adrenergic receptor stimulation also causes arachidonic acid mobilization, presumably via phospholipase A2. This effect is blocked by yohimbine, quinacrine, removal of extracellular Ca2+, and pretreatment with pertussis toxin. Quinacrine and removal of extracellular Ca2+, in contrast, have no effect on the enhanced forskolin-stimulated cyclic AMP production. Thus, it appears that the alpha 2-adrenergic receptor in these cells can simultaneously activate distinct signal transduction systems; inhibition of adenylate cyclase and stimulation of phospholipase A2, both via G1, and potentiation of cyclic AMP production by a different (pertussis toxin-insensitive) mechanism

  11. Alpha 2-adrenergic receptor stimulation of phospholipase A2 and of adenylate cyclase in transfected Chinese hamster ovary cells is mediated by different mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.B.; Halenda, S.P.; Bylund, D.B. (Univ. of Missouri-Columbia (USA))

    1991-02-01

    The effect of alpha 2-adrenergic receptor activation on adenylate cyclase activity in Chinese hamster ovary cells stably transfected with the alpha 2A-adrenergic receptor gene is biphasic. At lower concentrations of epinephrine forskolin-stimulated cyclic AMP production is inhibited, but at higher concentrations the inhibition is reversed. Both of these effects are blocked by the alpha 2 antagonist yohimbine but not by the alpha 1 antagonist prazosin. Pretreatment with pertussis toxin attenuates inhibition at lower concentrations of epinephrine and greatly potentiates forskolin-stimulated cyclic AMP production at higher concentrations of epinephrine. alpha 2-Adrenergic receptor stimulation also causes arachidonic acid mobilization, presumably via phospholipase A2. This effect is blocked by yohimbine, quinacrine, removal of extracellular Ca2+, and pretreatment with pertussis toxin. Quinacrine and removal of extracellular Ca2+, in contrast, have no effect on the enhanced forskolin-stimulated cyclic AMP production. Thus, it appears that the alpha 2-adrenergic receptor in these cells can simultaneously activate distinct signal transduction systems; inhibition of adenylate cyclase and stimulation of phospholipase A2, both via G1, and potentiation of cyclic AMP production by a different (pertussis toxin-insensitive) mechanism.

  12. Effect of Bcl-xL overexpression on sialylation of Fc-fusion protein in recombinant Chinese hamster ovary cell cultures.

    Science.gov (United States)

    Lee, Jong Hyun; Kim, Yeon-Gu; Lee, Gyun Min

    2015-01-01

    The sialic acid of glycoproteins secreted by recombinant Chinese hamster ovary (rCHO) cells can be impaired by sialidase under culture conditions which promote the extracellular accumulation of this enzyme. To investigate the effect of Bcl-xL overexpression on the sialylation of glycoproteins produced in rCHO cell culture, two rCHO cell lines producing the same Fc-fusion protein, which were derived from DUKX-B11 and DG44, respectively, were engineered to have regulated Bcl-xL overexpression using the Tet-off system. For both cell lines, Bcl-xL overexpression improved cell viability and extended culture longevity in batch cultures. As a result, a maximum Fc-fusion protein titer increased by Bcl-xL overexpression though the extent of titer enhancement differed between the two cell lines. With Bcl-xL overexpression, the sialylation of Fc-fusion protein, which was assessed by isoelectric focusing gel and sialic acid content analyses, decreased more slowly toward the end of batch cultures. This was because Bcl-xL overexpression delayed the extracellular accumulation of sialidase activity by reducing cell lysis during batch cultures. Taken together, Bcl-xL overexpression in rCHO cell culture increased Fc-fusion protein production and also reduced the impairment of sialylation of Fc-fusion protein by maintaining high viability during batch cultures. © 2015 American Institute of Chemical Engineers.

  13. X-ray induction of 6-thioguanine-resistant mutants in division arrested, G0/G1 phase Chinese hamster ovary cells

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, J.P.; Flint, K.B.

    The cytotoxic and mutagenic effect of X-irradiation was determined with Chinese hamster ovary cells arrested in the G0/G1 phase of the cell cycle through 9 days incubation in serum-free medium. In comparison with exponential phase cultures, the arrested cells showed increased cytotoxicity and mutation induction over the dose range of 50-800 rad. Exponential cultures showed a linear mutant frequency-survival relationship while the arrested cells showed a biphasic linear relationship. A post irradiation holding period 24 h does not result in any change in the mutant frequency. The increased sensitivity of the arrested cells to the mutagenic effects of X-rays appears to be a cell-cycle phase phenomenon. Upon readdition of serum, the arrested cells re-enter the cell cycle in a synchronous manner, reaching S phase at 10-12 h. Cells irradiated at 5 h after serum addition, i.e. in G1, show a similar dose response for mutant frequency, while those irradiated at 10 h or later, i.e. in late G1, S or G2, show lower mutation induction. These observations are consistent with a chromosome interchange mechanism of mutation induction by X-rays, possibly through interactions between repairing regions of the DNA. Irradiation of cells in the G0/G1 phase allow more time for such interactions in the absence of semiconservative DNA replication. (orig.).

  14. Evaluating the toxicity of TiO2-based nanoparticles to Chinese hamster ovary cells and Escherichia coli: a complementary experimental and computational approach

    Directory of Open Access Journals (Sweden)

    Alicja Mikolajczyk

    2017-10-01

    Full Text Available Titania-supported palladium, gold and bimetallic nanoparticles (second-generation nanoparticles demonstrate promising photocatalytic properties. However, due to unusual reactivity, second-generation nanoparticles can be hazardous for living organisms. Considering the ever-growing number of new types of nanoparticles that can potentially contaminate the environment, a determination of their toxicity is extremely important. The main aim of presented study was to investigate the cytotoxic effect of surface modified TiO2-based nanoparticles, to model their quantitative nanostructure–toxicity relationships and to reveal the toxicity mechanism. In this context, toxicity tests for surface-modified TiO2-based nanoparticles were performed in vitro, using Gram-negative bacteria Escherichia coli and Chinese hamster ovary (CHO-K1 cells. The obtained cytotoxicity data were analyzed by means of computational methods (quantitative structure–activity relationships, QSAR approach. Based on a combined experimental and computational approach, predictive models were developed, and relationships between cytotoxicity, size, and specific surface area (Brunauer–Emmett–Teller surface, BET of nanoparticles were discussed.

  15. Evaluation of phenolphthalein, diazepam and quinacrine dihydrochloride in the in vitro mammalian cell micronucleus test in Chinese hamster ovary (CHO) and TK6 cells.

    Science.gov (United States)

    Schuler, Maik; Gudi, Ramadevi; Cheung, Jennifer; Kumar, Shyam; Dickinson, Donna; Engel, Maria; Szkudlinska, Anna; Colman, Megan; Maduka, Nkechi; Sherman, Jocelyn; Thiffeault, Catherine

    2010-10-29

    The in vitro micronucleus assay has been extensively used as an in vitro screening tool to identify test articles that might have aneugenic or clastogenic potential. Currently, the Organization for Economic Co-operation and Development (OECD) is working towards a final version of the guideline for the conduct of the in vitro mammalian cell micronucleus Test (MNvit). A few questions regarding appropriate cytotoxicity measurements and cytotoxicity limits to use remain to be answered. In order to resolve the remaining questions, we compared the induction of micronuclei at the top dose (50-60% cytotoxicity) determined by either Relative Cell Counts (RCC), Relative Increase in Cell Counts (RICC), Relative Population Doublings (RPD), or Cytokinesis-Blocked Proliferating Index (CBPI) using weak and strong inducers of micronuclei in both the presence and absence of cytochalasin B (CYB) in Chinese hamster ovary (CHO) and human lymphoblastoid TK6 cells. In order to assess extensive dose-response relationships, we selected expected weak (diazepam, phenolphthalein, quinacrine dihydrochloride dihydrate) and strong (cytosine arabinoside, mitomycin C, vinblastine sulphate) inducers of micronuclei with a variety of different mechanisms of action for testing. The results clearly demonstrated that all six compounds produced positive responses using either cytotoxicity measurement. The outcome from these studies further supports the cytotoxicity measurements and cytotoxicity limits proposed in the draft OECD guideline. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Development, qualification, validation and application of the neutral red uptake assay in Chinese Hamster Ovary (CHO) cells using a VITROCELL® VC10® smoke exposure system.

    Science.gov (United States)

    Fields, Wanda; Fowler, Kathy; Hargreaves, Victoria; Reeve, Lesley; Bombick, Betsy

    2017-04-01

    Cytotoxicity assessment of combustible tobacco products by neutral red uptake (NRU) has historically used total particulate matter (TPM) or solvent captured gas vapor phase (GVP), rather than fresh whole smoke. Here, the development, validation and application of the NRU assay in Chinese Hamster Ovary (CHO) cells, following exposure to fresh whole smoke generated with the VITROCELL® VC10® system is described. Whole smoke exposure is particularly important as both particulate and vapor phases of tobacco smoke show cytotoxicity in vitro. The VITROCELL® VC10® system provides exposure at the air liquid interface (ALI) to mimic in vivo conditions for assessing the toxicological impact of smoke in vitro. Instrument and assay validations are crucial for comparative analyses. 1) demonstrate functionality of the VITROCELL® VC10® system by installation, operational and performance qualification, 2) develop and validate a cellular system for assessing cytotoxicity following whole smoke exposure and 3) assess the whole smoke NRU assay sensitivity for statistical differentiation between a reference combustible cigarette (3R4F) and a primarily "heat-not-burn" cigarette (Eclipse). The VITROCELL® VC10® provided consistent generation and delivery of whole smoke; exposure-related changes in in vitro cytotoxicity were observed with reproducible IC 50 values; comparative analysis showed that the heat-not-burn cigarette was significantly (PR4F combustible cigarette, consistent with the lower levels of chemical constituents liberated by primarily-heating the cigarette versus burning. Copyright © 2017. Published by Elsevier Ltd.

  17. Effects of clonal variation on growth, metabolism, and productivity in response to trophic factor stimulation: a study of Chinese hamster ovary cells producing a recombinant monoclonal antibody.

    Science.gov (United States)

    Dahodwala, Hussain; Nowey, Mark; Mitina, Tatyana; Sharfstein, Susan T

    2012-01-01

    The growth, metabolism, and productivity of five Chinese hamster ovary (CHO) clones were explored in response to stimulation with insulin (5 mg/L) and LONG(®)R(3)IGF-I (20 μg/L or 100 μg/L). All five clones were derived from the same parental CHO cell line (DG44) and produced the same recombinant monoclonal antibody, with varying specific productivities. There was no uniform response among the clones to stimulation with the different trophic factors. One of the high productivity clones (clone D) exhibited significantly better growth in response to LONG(®)R(3)IGF-I; whereas the other clones showed equivalent or slightly better growth in the presence of insulin. Three out of the five clones had higher specific productivities in the presence of insulin (although not statistically significant); one was invariant, and the final clone exhibited slightly higher specific productivity in the presence of LONG(®)R(3)IGF-I. Total product titers exhibited moderate variation between culture conditions, again with neither trophic factor being clearly superior. Overall product titers were affected by variations in both integrated viable cell density and specific productivity. Nutrient uptake and metabolite generation patterns varied strongly between clones and much less with culture conditions. These results point to the need for careful clonal analysis when selecting clones, particularly for platform processes where media and culture conditions are predetermined.

  18. A novel function for selenium in biological system: selenite as a highly effective iron carrier for Chinese hamster ovary cell growth and monoclonal antibody production.

    Science.gov (United States)

    Zhang, Jinyou; Robinson, David; Salmon, Peter

    2006-12-20

    As the market for biopharmaceuticals especially monoclonal antibodies (MAbs) rapidly grows, their manufacturing methods are coming under increasing regulatory scrutiny, particularly due to concerns about the potential introduction of adventitious agents from animal-sourced components in the media used for their production in mammalian cell culture. Chinese hamster ovary (CHO) cells are by far the most commonly used production vehicles for these recombinant glycoproteins. In developing animal-component free media for CHO and other mammalian cell lines, the iron-transporter function of serum or human/bovine transferrin is usually replaced by certain organic or inorganic chelators capable of delivering iron for cell respiration and metabolism, but few of them are sufficiently effective. Selenium is a well-known essential trace element (TE) for cell growth and development, and its positive role in biological system includes detoxification of free radicals by activating glutathione peroxidase. In cell culture, selenium in the form of selenite can help cells to detoxify the medium thus protect them from oxidative damage. In this presentation, we describe the discovery and application of a novel function of selenite, that is, as a highly effective carrier to deliver iron for cell growth and function. In our in-house-developed animal protein-free (APF) medium for CHO cells, using an iron-selenite compound to replace the well-established tropolone delivery system for iron led to comparable or better cell growth and antibody production. A high cell density of >10 x 10(6) viable cells/mL and excellent antibody titer of approximately 3 g/L were achieved in 14-day fed-batch cultures in shake flasks, followed by successful scale-up to stirred bioreactors. The preparation of the commercially unavailable iron-selenite compound from respective ions, and its effectiveness in cell-culture performance, were dependent on reaction time, substrates, and other conditions. Copyright 2006

  19. Phenylpropanoids from cinnamon bark reduced β-amyloid production by the inhibition of β-secretase in Chinese hamster ovarian cells stably expressing amyloid precursor protein.

    Science.gov (United States)

    Kang, Yu Jeong; Seo, Dae-Gun; Park, So-Young

    2016-11-01

    β-Amyloid (Aβ) is a substance of Alzheimer disease (AD), which is generated via the amyloidogenic pathway from amyloid precursor protein (APP) by β-secretase and γ-secretase. Inhibition of Aβ production is a potential therapeutic approach to AD. Thus, we tested the hypothesis that cinnamon bark (Cinnamomi Cortex Spissus), the dried bark of Cinnamomum cassia Blume (Lauraceae), and its constituents are beneficial to AD. The methanol extract of cinnamon bark efficiently reduced Aβ40 production in Chinese hamster ovarian (CHO) cells stably expressing APP as determined by enzyme-linked immunosorbent assay. Bioassay-guided isolation of cinnamon bark extract was carried out using open column chromatography and high-performance liquid chromatography, and the following 6 phenylpropanoids were isolated: syringaresinol (1); medioresinol (2); coumarin (3); 2-hydroxycinnamaldehyde (4); cryptamygin A (5); and 3',5,7-trimethoxy epicatechin (6). Among these, 4 μg/mL medioresinol and cryptamygin A reduced Aβ40 production by 50% and 60%, respectively, compared with dimethyl sulfoxide-treated control cells. The IC 50 values of medioresinol and cryptamygin A for the inhibition of Aβ40 production were 10.8 and 8.2 μg/mL, respectively. Furthermore, treatment of APP-CHO cells with either compound decreased the amount of β-secretase and sAPPβ (the proteolytic fragment of APP catalyzed by β-secretase). These results suggest that the antiamyloidogenic activity of cinnamon bark extract was exerted by medioresinol and cryptamygin A via a reduction in the amount of β-secretase. The extract of cinnamon bark contains potentially valuable antiamyloidogenic agents for the prevention and treatment of AD. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. The impact of homologous recombination repair deficiency on depleted uranium clastogenicity in Chinese hamster ovary cells: XRCC3 protects cells from chromosome aberrations, but increases chromosome fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Joyce, Kellie [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Xie, Hong [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Falank, Carolyne [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); and others

    2014-04-15

    Highlights: • The role of homologous recombination repair in DU-induced toxicity was examined. • Loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. • XRCC3 protects cell from DU-induced chromosome breaks and fusions. • XRCC3 plays a role in DU-induced chromosome fragmentation of the X chromosome. - Abstract: Depleted uranium (DU) is extensively used in both industry and military applications. The potential for civilian and military personnel exposure to DU is rising, but there are limited data on the potential health hazards of DU exposure. Previous laboratory research indicates DU is a potential carcinogen, but epidemiological studies remain inconclusive. DU is genotoxic, inducing DNA double strand breaks, chromosome damage and mutations, but the mechanisms of genotoxicity or repair pathways involved in protecting cells against DU-induced damage remain unknown. The purpose of this study was to investigate the effects of homologous recombination repair deficiency on DU-induced genotoxicity using RAD51D and XRCC3-deficient Chinese hamster ovary (CHO) cell lines. Cells deficient in XRCC3 (irs1SF) exhibited similar cytotoxicity after DU exposure compared to wild-type (AA8) and XRCC3-complemented (1SFwt8) cells, but DU induced more break-type and fusion-type lesions in XRCC3-deficient cells compared to wild-type and XRCC3-complemented cells. Surprisingly, loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. DU induced selective X-chromosome fragmentation irrespective of RAD51D status, but loss of XRCC3 nearly eliminated fragmentation observed after DU exposure in wild-type and XRCC3-complemented cells. Thus, XRCC3, but not RAD51D, protects cells from DU-induced breaks and fusions and also plays a role in DU-induced chromosome fragmentation.

  1. Comparative study of the cytotoxic and genotoxic effects of titanium oxide and aluminium oxide nanoparticles in Chinese hamster ovary (CHO-K1) cells

    Energy Technology Data Exchange (ETDEWEB)

    Di Virgilio, A.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata (1900) (Argentina); Reigosa, M. [Instituto Multidisciplinario de Biologia Celular (IMBICE), Calle 526 y Camino Gral. Belgrano (entre 10 y 11), La Plata 1900 (Argentina); Arnal, P.M. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina); Fernandez Lorenzo de Mele, M., E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina)

    2010-05-15

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO{sub 2}) and aluminium oxide (Al{sub 2}O{sub 3}) nanoparticles (NPs) on Chinese hamster ovary (CHO-K1) cells using neutral red (NR), mitochondrial activity (by MTT assay), sister chromatid exchange (SCE), micronucleus (MN) formation, and cell cycle kinetics techniques. Results showed a dose-related cytotoxic effect evidenced after 24 h by changes in lysosomal and mitochondrial dehydrogenase activity. Interestingly, transmission electronic microscopy (TEM) showed the formation of perinuclear vesicles in CHO-K1 cells after treatment with both NPs during 24 h but no NP was detected in the nuclei. Genotoxic effects were shown by MN frequencies which significantly increased at 0.5 and 1 {mu}g/mL TiO{sub 2} and 0.5-10 {mu}g/mL Al{sub 2}O{sub 3}. SCE frequencies were higher for cells treated with 1-5 {mu}g/mL TiO{sub 2}. The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO{sub 2}. No SCE induction was achieved after treatment with 1-25 {mu}g/mL Al{sub 2}O{sub 3}. In conclusion, findings showed cytotoxic and genotoxic effects of TiO{sub 2} and Al{sub 2}O{sub 3} NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  2. Effect of temperature shift on levels of acidic charge variants in IgG monoclonal antibodies in Chinese hamster ovary cell culture.

    Science.gov (United States)

    Kishishita, Shohei; Nishikawa, Tomoko; Shinoda, Yasuharu; Nagashima, Hiroaki; Okamoto, Hiroshi; Takuma, Shinya; Aoyagi, Hideki

    2015-06-01

    During the production of therapeutic monoclonal antibodies (mAbs), not only enhancement of mAb productivity but also control of quality attributes is critical. Charge variants, which are among the most important quality attributes, can substantially affect the in vitro and in vivo properties of mAbs. During process development for the production of mAbs in a Chinese hamster ovary cell line, we have observed that an improvement in mAb titer is accompanied by an increase in the content of acidic charge variants. Here, to help maintain comparability among mAbs, we aimed to identify the process parameters that controlled the content of acidic charge variants. First, we used a Plackett-Burman design to identify the effect of selected process parameters on the acidic charge variant content. Eight process parameters were selected by using a failure modes and effects analysis. Among these, temperature shift was identified from the Plackett-Burman design as the factor most influencing the acidic charge variant content. We then investigated in more detail the effects of shift temperature and temperature shift timing on this content. The content decreased with a shift to a lower temperature and with earlier timing of this temperature shift. Our observations suggest that Plackett-Burman designs are advantageous for preliminary screening of bioprocess parameters. We report here for the first time that temperature downshift is beneficial for effective control of the acidic peak variant content. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. High levels of histone H3 acetylation at the CMV promoter are predictive of stable expression in Chinese hamster ovary cells.

    Science.gov (United States)

    Moritz, Benjamin; Woltering, Laura; Becker, Peter B; Göpfert, Ulrich

    2016-05-01

    Chinese hamster ovary cells (CHO) are widely used in the production of glycosylated therapeutic proteins such as antibodies. During expansion and maintenance, CHO cell lines are prone to production instability, which may be caused by promoter silencing, loss of transgene copies, or post-transcriptional effects. Silencing of recombinant genes may be accompanied by DNA methylation and histone modification. Previously, we demonstrated that cytosine methylation of the human cytomegalovirus major immediate early promoter/enhancer (hCMV-MIE) can be used to predict instability of antibody-producing CHO cell lines. However, the high rate of false prediction motivates the search for further markers of stable promoter activity. To this end, we correlated a variety of histone modifications in the vicinity of hCMV-MIE with production stability over time. Our results suggest that acetylation of histone H3 (H3ac) is a more effective indicator of production stability than DNA methylation. Selecting cell lines with highest CMV promoter H3ac levels enriches stable expressors and improves the average stability of production cell lines. For histone H3 acetylation measurement we employed a method based on chromatin immunoprecipitation (ChIP). In its current form, the method is suitable to evaluate 10-20 cell lines within a few days. We propose to determine H3 acetylation once the number of candidate cell lines has been narrowed based on productivity and product quality. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:776-786, 2016. © 2016 American Institute of Chemical Engineers.

  4. Influence of cell cycle phase on radiation-induced cytotoxicity and DNA damage in human colon cancer (HT29) and Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Tang, H.; Davis, M.A.; Strickfaden, S.M.; Maybaum, J.; Lawrence, T.S.

    1994-01-01

    We have previously shown that fluorodeoxyuridine (FdUrd) radiosensitizes HT29 human colon carcinoma cells. Since treatment with FdUrd arrests cells at the G 1 /S-phase interface, a condition associated with increased radiation sensitivity in some cells, it seemed possible that redistribution of cells in the phases of the cell cycle might account for FdUrd-mediated radiosensitization. To begin to test this, HT29 cells were separated by centrifugal elutriation according to cell cycle phase and assessed for radiosensitivity, using a clonogenic assay, and radiation-induced DNA damage, using pulsed-field gel electrophoresis. We found that all of the elutriated fractions (which contained cells enriched in G 1 , G 1 /early S, mid to late S or G 2 /M phase) had the same radiation sensitivity and expressed a similar extent of radiation-induced DNA damage. To determine if the techniques used in this study could detect differences between the radiation sensitivity of cells in different phases of the cell cycle, analogous experiments were carried out using Chinese hamster ovary (CHO) cells. In contrast with the results of experiments with HT29 cells, but in agreement with previous studies, CHO cells separated under the same conditions as were used for HT29 cells showed a marked dependence on cell age of both clonogenic survival and radiation-induced DNA damage. Thus, within the limitations of the purity of separation obtained using elutriation, the radiation sensitivity of HT29 cells does not vary substantially as a function of cell cycle phase. Therefore, it seems unlikely that cell cycle redistribution alone explains the radiation sensitivity produced by exposure to FdUrd. 20 refs., 4 figs., 1 tab

  5. Effect of caffeine on gamma-ray induced G2 arrest in well-synchronized Chinese hamster ovary cells in vitro

    International Nuclear Information System (INIS)

    Masunaga, Shin-ichiro; Keng, P.C.

    1996-01-01

    G1-rich cells were separated from exponentially growing asynchronous cultured Chinese hamster ovary (CHO-K1) cells by centrifugal elutriation and a Coulter Counter. The G1-rich cells were incubated in medium that contained hydroxyurea (HU) to kill S phase cells and obtain the purest G1/S boundary cells possible. The HU-treated cells were washed, and were again incubated, in medium without HU, to allow these well-synchronized G1/S boundary cells to progress to S and G2/M phases. At various times after release from G1/S boundary, 4 Gy of gamma-ray and/or caffeine was administered to the cells. Eight hours after the removal of HU, cell-cycle analysis was performed with a flow cytometer. G2 arrest induced by gamma-rays was clearly shown when radiation was given earlier than 6.5 hours after HU removal. G2 arrest induced by radiation given 0.5-6.5 hours after HU removal was reduced by caffeine treatment given 6.0-6.5 hours after HU removal. Caffeine released radiation-induced G2 arrest when the radiation was given before the cultured cells entered G2/M phase and when caffeine was applied to the irradiated cells at the time when G1/S boundary cells not treated by radiation or with caffeine entered G2/M phase. Our method of centrifugal elutriation combined with incubation with HU was useful for isolating pure G1/S boundary cells from in vitro asynchronous cultures. (author)

  6. Inverse dose-rate effect for the induction of 6-thioguanine-resistant mutants in Chinese hamster V79-S cells by 60Co gamma rays

    International Nuclear Information System (INIS)

    Crompton, N.E.; Barth, B.; Kiefer, J.

    1990-01-01

    Chinese hamster V79-S cells capable of growing in suspension culture were exposed to 60Co gamma rays at a high dose rate (84 Gy/h), low dose rates (200, 50, and 39 mGy/h), and a spectrum of very low dose rates (between 29 and 4.5 mGy/h). Following time for appropriate expression the cultures were assayed for the induction of 6-thioguanine-resistant mutants. For a given dose, a decrease in mutation induction occurred as the dose rate was reduced from high dose rates to low dose rates. However, further reduction in dose rate resulted in a reverse dose-rate effect, and an increase in the frequency of mutants was observed. The contribution of background mutation frequency to this reverse dose-rate effect was studied, both by examining fluctuations of mutation frequency in nonirradiated culture and by its impact upon the dose-rate-independent nature of the reversed effect, and it was found to be negligible. The physiological state of the suspension culture under periods of protracted exposure to very low dose rates was also investigated. The effect of doubling time, plating efficiency, cell cycle distribution, and sensitivity on survival and mutation were examined. In no case was a change apparent during the very low-dose-rate exposures. The results are discussed in terms of the possible expression of cryptic radiation damage after prolonged culture times and/or the involvement of an error-free repair system which requires a certain amount of radiation damage to become active

  7. Syntheses and modulations in the chromatin contents of histones H1/sup o/ and H1 during G1 and S phases in Chinese hamsters cells

    International Nuclear Information System (INIS)

    D'Anna, J.A.; Gurley, L.R.; Tobey, R.A.

    1982-01-01

    Flow cytometry, conventional autoradiography, and autoradiography employing high concentrations of high specific activity [ 3 H]thymidine indicate that (1) treatment of Chinese hamster ovary (line CHO) cells with butyrate truly blocks cells in G 1 and (2) cells blocked in G 1 by isoleucine deprivation remain blocked in G 1 when they are released into complete medium containing butyrate. Measurements of H1/sup o/ content relative to core histones and H1/sup o/:H1 ratios indicate that H1/sup o/ is enhanced somewhat in G 1 cells arrested by isoleucine deprivation; however, (1) treatment with butyrate greatly increases the H1/sup o/ content in G 1 -blocked cells, and (2) the enhancement is very sensitive to butyrate concentration. Measurements of relative histone contents in the isolated chromatin of synchronized cultures also suggest that the acid-soluble content of histone H1 (relative to core histones) becomes greatly depleted in the isolated chromatin when synchronized cells are blocked in early S phase by sequential use of isoleucine deprivation and hydroxyurea blockade. We also have measured [ 3 H]lysine incorporation, various protein ratios, and relative rates of deposition of newly synthesized H1/sup o/, H1, and H4 onto chromatin during G 1 and S in the absence of butyrate. The results suggest a dynamic picture of chromatin organization in which (1) newly synthesized histone H1/sup o/ binds to chromatin during traverse of G 1 and S phases and (2) histone H1 dissociates from (or becomes loosely bound to) chromatin during prolonged early S-phase block with hydroxyurea

  8. [Study on the immuno-effects and influencing factors of Chinese hamster ovary (CHO) cell hepatitis B vaccine among adults, under different dosages].

    Science.gov (United States)

    Zhang, Wei; Lin, Chang-ying; Han, Li-li; Li, Li-qiu; Gao, Pei; Lin, Hui; Gong, Xiao-hong; Huang, Fang; Tang, Ya-qing; Ma, Jian-xin; Zhang, Hai-yan; Wang, Chen; Yang, Peng; Li, Hui; Sun, Mei-ping; He, Xiong; Pang, Xing-huo

    2010-07-01

    To evaluate the immuno-effect and related influencing factors on 10 µg and 20 µg Chinese hamster ovary (CHO) cell hepatitis B vaccine, using the randomized double-blind controlled trials in adult population. A total of 642 adults aged 18 - 45 years old, non-vaccinated against hepatitis B, and negative on five blood indicators for hepatitis B, were selected as the study objects from four districts in Beijing. The study objects were randomly divided into two groups, and then accepted 10 µg and 20 µg recombinant CHO hepatitis B vaccination by 0 - 1 - 6 month schedule. Influencing factors were investigated by means of questionnaire. Blood samples were collected one month after the third dose of vaccination. Anti-HBs level was detected by Abott chemiluminescence detection method. For the anti-HBs negative person, fluorescent quantitative PCR method was used to find out if the person had been infected with HBV. Logistic regression analysis was used to find out the influencing factors of anti-HBs seroconversion on every studied subject. The anti-HBs seroconversion rates on 10 µg and 20 µg dose groups were 88.8% (95%CI: 85.4% - 92.2%) and 95.3% (95%CI: 93.0% - 97.6%) respectively. Taking the anti-HBs level anti-HBs were 173.42 mIU/ml for the 10 µg dose group and 588.51 mIU/ml for the 20 µg dose group. Data from the Multivariate analysis showed that:diabetes, spouses infected with hepatitis B virus and old age were unfavorable factors for anti-HBs Seroconversion. 20 µg dose of the vaccine was conducive to seroconversion. 20 µg CHO hepatitis B vaccine seemed better than 10 µg CHO hepatitis B vaccine while many factors need to be taken into account for evaluation on hepatitis B vaccines.

  9. Inhibition of serine palmitoyltransferase in vitro and long-chain base biosynthesis in intact Chinese hamster ovary cells by β-chloroalanine

    International Nuclear Information System (INIS)

    Medlock, K.A.; Merrill, A.H. Jr.

    1988-01-01

    The effects of β-chloroalanine (β-Cl-alanine) on the serine palmitoyltransferase activity and the de novo biosynthesis of sphinganine and sphingenine were investigated in vitro with rat liver microsomes and in vivo with intact Chinese hamster ovary (CHO) cells. The inhibition in vitro was rapid, irreversible, and concentration and time dependent and apparently involved the active site because inactivation only occurred with β-Cl-L-alanine and was blocked by L-serine. These are characteristics of mechanism-based (suicide) inhibition. Serine palmitoyltransferase (SPT) was also inhibited when intact CHO cells were incubated with β-Cl-alanine and this treatment inhibited [ 14 C]serine incorporation into long-chain bases by intact cells. The concentration dependence of the loss of SPT activity and of long-chain base synthesis was identical. The effects of β-Cl-alanine appeared to occur with little perturbation of other cell functions: the cells exhibited no loss in cell viability, [ 14 C]serine uptake was not blocked, total lipid biosynthesis from [ 14 C]acetic acid was not decreased (nor was the appearance of radiolabel in cholesterol and phosphatidylcholine), and [ 3 H]thymidine incorporation into DNA was not affected. There appeared to be little effect on protein synthesis based on the incorporation of [ 3 H]leucine, which was only decreased by 14%. Although β-Cl-L-alanine is known to inhibit other pyridoxal 5'-phosphate dependent enzymes, alanine and aspartate transaminases were not inhibited under these conditions. These results establish the close association between the activity of serine palmitoyltransferase and the cellular rate of long-chain base formation and indicate that β-Cl-alanine and other mechanism-based inhibitors might be useful to study alterations in cellular long-chain base synthesis

  10. Induction of DNA double-strand breaks by restriction enzymes in X-ray-sensitive mutant Chinese hamster ovary cells measured by pulsed-field gel electrophoresis

    International Nuclear Information System (INIS)

    Kinashi, Yuko; Nagasawa, Hatsumi; Little, J.B.; Okayasu, Ryuichi; Iliakis, G.E.

    1995-01-01

    This investigation was designed to determine whether the cytotoxic effects of different restriction endonucleases are related to the number and type of DNA double-strand breaks (DSBs) they produce. Chinese hamster ovary (CHO) K1 and xrs-5 cells, a radiosensitive mutant of CHO K1, were exposed to restriction endonucleases HaeIII, HinfI, PvuII and BamHI by electroporation. These enzymes represent both blunt and sticky end cutters with differing recognition sequence lengths. The number of DSBs was measured by pulsed-field gel electrophoresis (PFGE). Two forms of PFGE were employed: asymmetric field-inversion gel electrophoresis (AFIGE) for measuring the kinetics of DNA breaks by enzyme digestion and clamped homogeneous gel electrophoresis (CHEF) for examining the size distributions of damaged DNA. The amount of DNA damage induced by exposure to all four restriction enzymes was significantly greater in xrs-5 compared to CHO K1 cells, consistent with the reported DSB repair deficiency in these cells. Since restriction endonucleases produce DSBs alone as opposed to the various types of DNA damage induced by X rays, these results confirm that the repair defect in this mutant involves the rejoining of DSBs. Although the cutting frequency was directly related to the length of the recognition sequence for four restriction enzymes, there was no simple correlation between the cytotoxic effect and the amount of DNA damage produced by each enzyme in either cell line. This finding suggests that the type or nature of the cutting sequence itself may play a role in restriction enzyme-induced cell killing. 32 refs., 6 figs., 3 tabs

  11. Mechanism of resistance of noncycling mammalian cells to 4'-(9-acridinylamino)methanesulfon-m-anisidide: comparison of uptake, metabolism, and DNA breakage in log- and plateau-phase Chinese hamster fibroblast cell cultures

    International Nuclear Information System (INIS)

    Robbie, M.A.; Baguley, B.C.; Denny, W.A.; Gavin, J.B.; Wilson, W.R.

    1988-01-01

    Resistance of noncycling cells to amsacrine (m-AMSA) has been widely reported and may limit the activity of this drug against solid tumors. The biochemical mechanism(s) for this resistance have been investigated using spontaneously transformed Chinese hamster fibroblasts (AA8 cells, a subline of Chinese hamster ovary-cells) in log- and plateau-phase spinner cultures. In early plateau phase most cells entered a growth-arrested state with a G1-G0 DNA content and showed a marked decrease in sensitivity to cytotoxicity induced by a 1-h exposure to m-AMSA or to its solid tumor-active analogue, CI-921. Studies with radiolabeled m-AMSA established that similar levels of drug were accumulated by log- and plateau-phase cells and that there was no significant drug metabolism in either of these cultures after 1 h. However, marked differences in sensitivity to m-AMSA-induced DNA breakage were observed using a fluorescence assay for DNA unwinding. Changes in sensitivity to DNA breakage occurred in parallel with changes in sensitivity to m-AMSA-induced cell killing. DNA breaks disappeared rapidly after drug removal (half-time approximately 4 min), suggesting that these lesions were probably mediated by DNA topoisomerase II. Resistance to m-AMSA may therefore be associated with changes in topoisomerase II activity in noncycling cells

  12. In vitro genotoxic and cytotoxic effects of ivermectin and its formulation ivomec on Chinese hamster ovary (CHO{sub K1}) cells

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, G.; Soloneski, S.; Reigosa, M.A. [Catedra de Citologia, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata (Argentina); Larramendy, M.L., E-mail: m_larramendy@hotmail.com [Catedra de Citologia, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata (Argentina)

    2009-06-15

    The effects of ivermectin (IVM) and its commercial formulation ivomec (IVM 1.0%) were studied on Chinese hamster ovary (CHO{sub K1}) cells by several genotoxicity [sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE)] and cytotoxicity [cell-cycle progression (CCP), mitotic index (MI), proliferative replication index (PRI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR)] bioassays within the 1.0-250 {mu}g/ml concentration-range. While IVM and ivomec did not modified SCE frequencies, they induced DNA-strand breaks revealed by SCGE. An enhancement of slightly damaged cells and a decrease in undamaged cells were observed in IVM-treated cultures with 5.0-50.0 {mu}g/ml. In ivomec-treated cells, while an increase in slightly damaged cells was induced with 5.0-50.0 {mu}g/ml, the damaged and undamaged cells increased and decreased only with 50.0 {mu}g/ml. Both compounds exerted a delay in CCP and a reduction in PRI when 25.0 {mu}g/ml was employed whereas cytotoxicity was observed at higher concentration than 50.0 {mu}g/ml. No MI alteration was observed with 1.0-10.0 and 1.0-5.0 {mu}g/ml of IVM and ivomec, respectively. A concentration-related trend to an increase in MI was achieved within 1.0-10.0 {mu}g/ml. An increase in the MI was induced in 10.0 {mu}g/ml ivomec-treated cultures. A marked reduction of about 89% and 62% in regard to controls was observed with 25.0 {mu}g/ml of IVM and ivomec, respectively. NR and MTT assays revealed a cell growth inhibition when 0.25-250.0 {mu}g/ml of both compounds was employed. The results highlighted that IVM and ivomec exert both genotoxicity and cytotoxicity in mammalian cells in vitro, at least in CHO{sub K1} cells.

  13. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO

    International Nuclear Information System (INIS)

    Santos, Geyza Spigoti

    2011-01-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60 Co γ radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 μg/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400μ/ml) in PC3 cells irradiated with 5 Gγ. The survival curves obtained were adequately fitted by a linear-quadratic model, where the α coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 μg/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data obtained in vitro showed a

  14. Comparison of 6-thioguanine-resistant mutation and sister chromatid exchanges in Chinese hamster V79 cells with forty chemical and physical agents.

    Science.gov (United States)

    Nishi, Y; Hasegawa, M M; Taketomi, M; Ohkawa, Y; Inui, N

    1984-08-01

    The induction of sister chromatid exchanges (SCE) and mutation at the hypoxanthine-guanine phosphoribosyl transferase locus and toxicities of 40 different chemical and physical agents were examined on Chinese hamster V79 cells. These agents included mono-, di-, tri-, and polyfunctional alkylating agents, intercalators, gamma-rays, and UV light irradiation. Mutation was measured as resistance to 6-thioguanine and toxicity as loss of cell-plating efficiency. SCE were examined 29 hr after treatment. With the agents examined, a highly positive correlation (r = 0.89) existed between SCE-inducing and mutagenic potencies, when expressed as increase in the number per a unit dose over the control values. But the great difference of the ratios of mutagenic potencies versus SCE-inducing potencies among agents was observed, the maximal difference in the ratios being about 200-fold. The agents that showed the higher values of the ratio (agents producing more mutations than SCE) were bleomycin, cobalt-60 gamma-rays, all ethylating agents (N-ethyl-N-nitrosourea, N-ethyl-N'-nitro-N-nitrosoguanidine, ethyl methanesulfonate, and diethylsulfate), N-propyl-N-nitrosourea, N-butyl-N-nitrosourea, isopropyl methanesulfonate, intercalating acridine compounds (2-methoxy-6-chloro-9-[3-(ethyl-2-chloroethyl)aminopropylamino]-acridine X 2HCl and 2-methoxy-6-chloro-9-[3-(chloroethyl)-aminopropylamino]acridine 2HCl) and UV light at 254 nm. The agents that showed the lower values (agents producing more SCE than mutations) were platinum compounds (cis-diamminedichloro-platinum and trans-diamminedichloroplatinum), epoxides (epichlorohydrin, styrene oxide, and diepoxybutane) and aziridines (mitomycin C, decarbamoyl mitomycin C, tris(1-aziridinyl)phosphine sulfide, triethylenemelamine, and carboquone). The agents that showed the intermediate values included all methylating agents (N-methyl-N-nitrosourea, N-methyl-N'-nitro-N-nitrosoguanidine, methyl methanesulfonate, and dimethyl sulfate), N-(2

  15. The β4 subunit of the voltage-gated calcium channel (Cacnb4) regulates the rate of cell proliferation in Chinese Hamster Ovary cells.

    Science.gov (United States)

    Rima, Mohamad; Daghsni, Marwa; De Waard, Stephan; Gaborit, Nathalie; Fajloun, Ziad; Ronjat, Michel; Mori, Yasuo; Brusés, Juan L; De Waard, Michel

    2017-08-01

    The β subunits of Voltage-Gated Calcium Channel (VGCC) are cytosolic proteins that interact with the VGCC pore -forming subunit and participate in the trafficking of the channel to the cell membrane and in ion influx regulation. β subunits also exert functions independently of their binding to VGCC by translocation to the cell nucleus including the control of gene expression. Mutations of the neuronal Cacnb4 (β 4 ) subunit are linked to human neuropsychiatric disorders including epilepsy and intellectual disabilities. It is believed that the pathogenic phenotype induced by these mutations is associated with channel-independent functions of the β 4 subunit. In this report, we investigated the role of β 4 subunit in cell proliferation and cell cycle progression and examined whether these functions could be altered by a pathogenic mutation. To this end, stably transfected Chinese Hamster Ovary (CHO-K1) cells expressing either rat full-length β 4 or the rat C-terminally truncated epileptic mutant variant β 1-481 were generated. The subcellular localization of both proteins differed significantly. Full-length β 4 localizes almost exclusively in the cell nucleus and concentrates into the nucleolar compartment, while the C-terminal-truncated β 1-481 subunit was less concentrated within the nucleus and absent from the nucleoli. Cell proliferation was found to be reduced by the expression of β 4 , while it was unaffected by the epileptic mutant. Also, full-length β 4 interfered with cell cycle progression by presumably preventing cells from entering the S-phase via a mechanism that partially involves endogenous B56δ, a regulatory subunit of the phosphatase 2A (PP2A) that binds β 4 but not β 1-481 . Analysis of β 4 subcellular distribution during the cell cycle revealed that the protein is highly expressed in the nucleus at the G1/S transition phase and that it is translocated out of the nucleus during chromatin condensation and cell division. These results

  16. Cadmium inhibits repair of UV-, methyl methanesulfonate- and N-methyl-N-nitrosourea-induced DNA damage in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Fatur, Tanja; Lah, Tamara T.; Filipic, Metka

    2003-01-01

    The co-genotoxic effects of cadmium are well recognized and it is assumed that most of these effects are due to the inhibition of DNA repair. We used the comet assay to analyze the effect of low, non-toxic concentrations of CdCl 2 on DNA damage and repair-induced in Chinese hamster ovary (CHO) cells by UV-radiation, by methyl methanesulfonate (MMS) and by N-methyl-N-nitrosourea (MNU). The UV-induced DNA lesions revealed by the comet assay are single-strand breaks which are the intermediates formed during nucleotide excision repair (NER). In cells exposed to UV-irradiation alone the formation of DNA strand breaks was rapid, followed by a fast rejoining phase during the first 60 min after irradiation. In UV-irradiated cells pre-exposed to CdCl 2 , the formation of DNA strand breaks was significantly slower, indicating that cadmium inhibited DNA damage recognition and/or excision. Methyl methanesulfonate and N-methyl-N-nitrosourea directly alkylate nitrogen and oxygen atoms of DNA bases. The lesions revealed by the comet assay are mainly breaks at apurinic/apyrimidinic (AP) sites and breaks formed as intermediates during base excision repair (BER). In MMS treated cells the initial level of DNA strand breaks did not change during the first hour of recovery; thereafter repair was detected. In cells pre-exposed to CdCl 2 the MMS-induced DNA strand breaks accumulated during the first 2 h of recovery, indicating that AP sites and/or DNA strand breaks were formed but that further steps of BER were blocked. In MNU treated cells the maximal level of DNA strand breaks was detected immediately after the treatment and the breaks were repaired rapidly. In CdCl 2 pre-treated cells the formation of MNU-induced DNA single-strand breaks was not affected, while the repair was slower, indicating inhibition of polymerization and/or the ligation step of BER. Cadmium thus affects the repair of UV-, MMS- and MNU-induced DNA damage, providing further evidence, that inhibition of DNA repair

  17. Comparison of five different in vitro assays for assessment of sodium metavanadate cytotoxicity in Chinese hamster ovary cells (CHO-K1 line).

    Science.gov (United States)

    Zwolak, Iwona

    2015-08-01

    This investigation was undertaken to compare five different in vitro cytotoxicity assays for their power in revealing vanadium-mediated toxicity in Chinese hamster ovary (CHO)-K1 cells. The cells were exposed to sodium metavanadate (NaVO(3)) in the range of 10-1000 µM for 24 h and thereafter the cytotoxic effects of NaVO(3) were measured by colorimetric in vitro assays: the neutral red (NR) test, the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt (XTT) assay, the resazurin assay, the sulforhodamine B (SR-B) assay, and by microscopic assessment of cell viability using the trypan blue (TB) staining method. Among the assays used, the NR test was the most sensitive, since it revealed metavanadate cytotoxicity at the lowest NaVO(3) dose (=50 µM). Also, NaVO(3) cytotoxicity expressed as inhibitory concentration (IC) showed the lowest values for the NR test. Three other tests XTT, resazurin, and SR-B assays showed intermediate sensitivity revealing the cytotoxicity of NaVO(3) at 100 µM. The corresponding IC10 and IC50 values calculated for the XTT, resazurin, and SR-B tests were similar. The TB staining method was the least sensitive, since it recorded metavanadate cytotoxicity at the highest NaVO(3) concentration tested (=600 µM). Based on the cytotoxicity end points measured with the above assays, it can be concluded that lysosomal/Golgi apparatus damage (measured by NR assay) may be the primary effect of NaVO(3) on CHO-K1 cells. The disintegration of mitochondria (assessed with the XTT and resazurin assays) probably follows lysosomal impairment. Plasma membrane permeability (staining with TB) occurs at a late stage of NaVO(3)-induced cytotoxicity on CHO-K1 cells. The results obtained in this research work show that the NR test can be recommended as a very sensitive assay for the assessment of NaVO(3) cytotoxicity in the CHO-K1 cell culture model. Considering the convenience of assay performance along with adequate sensitivity

  18. First genotoxicity study of Paraná river water from Argentina using cells from the clam Corbicula fluminea (Veneroida Corbiculidae and Chinese hamster (Cricetulus griseus Rodentia, Cricetidae K1 cells in the comet assay

    Directory of Open Access Journals (Sweden)

    Jacqueline D. Caffetti

    2008-01-01

    Full Text Available High concentrations of xenobiotics from urban and industrial wastes have contributed to the contamination of many aquatic environments. We used the comet assay to evaluate the genotoxic potential of water collected from the River Paraná, which receives a great deal of waste, at three points (Puerto Piray, Eldorado and Montecarlo in the Misiones Province of Argentina. The in vivo comet assay used 40 freshwater clams (Corbicula fluminea while the in vitro comet assay used Chinese hamster (Cricetulus griseus K1 cell (CHO-K1 cultures with the mutagen ethyl methanesulfonate (EMS as the positive control and phosphate buffered saline (PBS as the negative control. Both assays showed statistically significant differences between the three sampling sites in relation to the negative control, the results of this preliminary study indicating that at these three sites water from the Paraná River presents genotoxic potential.

  19. Response to high LET radiation 12C (LET, 295 keV/microm) in M5 cells, a radio resistant cell strain derived from Chinese hamster V79 cells.

    Science.gov (United States)

    Pathak, R; Sarma, A; Sengupta, B; Dey, S K; Khuda-Bukhsh, A R

    2007-01-01

    To study the effects of 12C-beam of 295 keV/microm (57.24 MeV) on M5 and Chinese hamster V79 cells by using cytogenetic assays like micronuclei (MN) induction, chromosomal aberrations (CA) and apoptosis. Additionally, the relative survival of these two cell lines was tested by the colony forming ability of the cells, with a view to understanding the mechanism of cellular damages that lead to difference in cell survival. Confluent cells were irradiated with 12C-beam at various doses using 15UD Pelletron accelerator. Cell survival was studied by the colony forming ability of cells. MN assay was done by fluorescent staining. Different types of chromosomal aberrations in metaphase cells were scored at 12 h after irradiation. Apoptosis was measured at different post irradiation times as detected by nuclear fragmentation and DNA ladder was prepared after 48 h of incubation. Dose-dependent decrease in surviving fractions was found in both the cell lines. However, the surviving fractions were higher in M5 cells in comparison to V79 cells when exposed to the same radiation doses. On the other hand, induced MN frequencies, CA frequencies and apoptosis percentages were less in M5 cells than V79 cells. Very good correlations between surviving fractions and induced MN frequencies or induced total CA or induced apoptosis percentages were obtained in this study. The cell strain M5 showed relatively more radio-resistance to 12C-beam compared to Chinese hamster V79 cells in this study. As the MN formation, CA and apoptosis induction were less in M5 cells as compared to parental V79 cells, the higher cell survival in the former could possibly be attributed to their better repairing ability leading to higher cell survival.

  20. Potentially lethal damage versus sublethal damage: independent repair processes in actively growing Chinese hamster cells. [Effects of osmotic pressure differences due to NaCl concentrations in buffer solutions on sensitivity of cells to x rays

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, H.; Elkind, M.M.

    1979-02-01

    Actively growing V79 Chinese hamster cells, treated with anisotonic phosphate-buffered saline (PBS) after x irradiation, are more sensitive than cells treated with isotonic PBS or cells promptly incubated with complete medium immediately after irradiation. The sensitization of irradiated cells results from hypotonic as well as hypertonic NaCl concentrations in PBS, is strongly dependent on both temperature and time, and is mainly due to an increase in the final slope of the single-dose survival curve. After two x-ray dose fractions, the net response of cells sensitized after each fraction by anisotonic post-treatment is similar to that obtained for isotonically treated cells and indicates that sublethal damage repair is not influenced by the enhanced expression of lethal damage. Independence of the repair of damage which is potentially lethal from the repair of damage which is sublethal is further suggested by the more rapid rate of the former compared to that of the latter. The proposal is advanced that the enhanced expression of damage which, after x irradiation, can be shown to be potentially lethal results from a destabilization of the structural relationship between DNA and the nuclear envelope, and/or DNA and the nuclear protein matrix, as a consequence of osmotic changes produced by anisotonic treatment.

  1. Effects of a tumor promoter and an anti-promoter on spontaneous and UV-induced 6-thioguanine-resistant mutations and sister-chromatid exchanges in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Fujiwara, Y.; Kano, Y.; Tatsumi, M.; Paul, P.

    1980-01-01

    The effects of a tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and/or an anti-promoter antipain (protease inhibitor) on spontaneous and ultraviolet-induced sister-chromatid exchanges (SCEs) and 6-thioguanine-resistant (6TGsup(r)) recessive mutations were examined in V79 Chinese hamster cells in culture. TPA and/or antipain neither significantly altered base-line and UV-induced immediate SCE frequencies, nor decreased the level of delayed SCEs which persisted 6-7 days after irradiation. TPA and/or antipain appeared to enhance the recovery of UV-induced 6TGsup(r) colonies at the plateau expression phase despite non-mutagenicity by themselves and unaltered metabolic cooperation. Thus, the results conceivably imply that the 6TGsup(r)-recessive mutation expression, but not fixation, can be modulated at the cell level by TPA and/or antipain. Our results, together with the recent results of Loveday and Latt, may argue against the notion that TPA enhances the antipain-suppressible SCEs as an index of mitotic recombination in relevance with a tumor-promotion mechanism. (orig.)

  2. Expression of type I and type II bovine scavenger receptors in Chinese hamster ovary cells: Lipid droplet accumulation and nonreciprocal cross competition by acetylated and oxidized low density lipoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, M. (Massachusetts Inst. of Tech., Cambridge (United States) Massachusetts General Hospital, Boston (United States)); Ekkel, Y.; Rohrer, L.; Penman, M.; Freedman, N.J.; Krieger, M. (Massachusetts Inst. of Tech., Cambridge (United States)); Chisolm, G.M. (Research Inst. of the Cleveland Clinic Foundation, OH (United States))

    1991-06-01

    Type I and type II scavenger receptors, which have been implicated in the development of atherosclerosis and other macrophage-associated functions, differ only by the presence in the type I receptor of an extracellular cysteine-rich C-terminal domain. Stable Chinese hamster ovary (CHO) cell transfectants expressing high levels of either the type I or type II bovine scavenger receptors have been generated. Type I and type II receptors in these cells mediated high-affinity saturable endocytosis of both {sup 125}I-labeled acetylated low density lipoprotein (LDL) and {sup 125}I-labeled oxidized LDL with the distinctive broad ligand specificity characteristic of scavenger receptors. After incubation for 2 days with acetylated LDL, the transfected cells accumulated oil red O-staining lipid droplets reminiscent of those in macrophage foam cells, whereas untransfected CHO cells did not. Thus, macrophage-specific gene products other than the scavenger receptor are not required for modified-LDL-induced intracellular lipid accumulation. In transfected cells, acetylated LDL efficiently competed for both its own endocytosis and that of oxidized LDL. This nonreciprocal cross competition suggests that these ligands may bind to nonidentical but interacting sites on a single receptor. Results were similar for transfectants expressing either type I or type II scavenger receptors. The nonreciprocal cross competition seen in the transfected CHO cells differs from that previously observed with cultured macrophages.

  3. Comparison of protein patterns of xrs-5, a radiosensitive Chinese hamster ovary cell line, and CHO-K1, its radioresistant parent, using two-dimensional gel-electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, J.M. (Miami Univ., Oxford, OH (USA). Dept. of Zoology)

    1991-01-01

    X-ray sensitive strains of Chinese hamster ovary cell lines have been used to analyze radiation repair mechanisms. One cell line, xrs-5, has been shown to be very sensitive to ionizing radiation and radical forming chemical mutagens. This sensitivity is thought to be a result a mutation in the DNA double strand break (DSB) repair mechanism, and its characterization has been a goal of several repair mechanism studies. Using two-dimensional gel electrophoresis, we have detected a protein (MW approximately 55KD) in the DNA/Nuclear Matrix (nucleoid) cell fraction of CHO-Kl cells that is absent in the nucleoid fraction of xrs-5. This protein is present, however, in both CHO-Kl and xrs-5 whole cell protein maps. To determine whether the 55KD protein is responsible for the radiosensitive and defective DSB repair phenotype of xrs-5 cells, studies are now underway to analyze revertants of xrs-5 that are proficient in DSB repair. Furthermore, an effort to sequence the protein in question is planned. 23 refs., 2 figs.

  4. Application of thermotolerant microorganisms for biofertilizer preparation.

    Science.gov (United States)

    Chen, Kuo-Shu; Lin, Yann-Shying; Yang, Shang-Shyng

    2007-12-01

    Intensive agriculture is practised in Taiwan, and compost application is very popular as a means of improving the soil physical properties and supplying plant nutrition. We tested the potential of inoculation with thermotolerant microorganisms to shorten the maturity and improve the quality of biofertilizer prepared by composting. Thermotolerant microorganisms were isolated from compost and reinoculated for the preparation of biofertilizer. The physical, chemical and biological properties of the biofertilizer were determined during composting. The effects of biofertilizer application on the growth and yield of rape were also studied. Among 3823 colonies of thermotolerant microorganisms, Streptomyces thermonitrificans NTU-88, Streptococcus sp. NTU-130 and Aspergillus fumigatus NTU-132 exhibited high growth rates and cellulolytic and proteolytic activities. When a mixture of rice straw and swine manure were inoculated with these isolates and composted for 61 days, substrate temperature increased initially and then decreased gradually during composting. Substrate pH increased from 7.3 to 8.5. Microbial inoculation enhanced the rate of maturity, and increased the content of ash and total and immobilized nitrogen, improved the germination rate of alfalfa seed, and decreased the content of total organic carbon and the carbon/nitrogen ratio. Biofertilizer application increased the growth and yield of rape. Inoculation of thermotolerant and thermophilic microorganisms to agricultural waste for biofertilizer preparation enhances the rate of maturity and improves the quality of the resulting biofertilizer. Inoculation of appropriate microorganisms in biofertilizer preparation might be usefully applied to agricultural situations.

  5. High glucose enhances cAMP level and extracellular signal-regulated kinase phosphorylation in Chinese hamster ovary cell: Usage of Br-cAMP in foreign protein β-galactosidase expression.

    Science.gov (United States)

    Lin, Hsiao-Hsien; Lee, Tsung-Yih; Liu, Ting-Wei; Tseng, Ching-Ping

    2017-07-01

    Glucose is a carbon source for Chinese hamster ovary (CHO) cell growth, while low growth rate is considered to enhance the production of recombinant proteins. The present study reveals that glucose concentrations higher than 1 g/L reduce the growth rate and substantially increase in cAMP (∼300%) at a high glucose concentration (10 g/L). High glucose also enhances the phosphorylation of extracellular signal-regulated kinase (ERK) and p27 kip by Western blot analysis. To determine whether the phosphorylation of ERK is involved in the mechanism, a cyclic-AMP dependent protein kinase A (PKA) inhibitor (H-8) or MEK (MAPKK) inhibitor (PD98059) was added to block ERK phosphorylation. We show that both the high glucose-induced ERK phosphorylation and growth rate return to baseline levels. These results suggest that the cAMP/PKA and MAP signaling pathways are involved in the abovementioned mechanism. Interestingly, the direct addition of 8-bromo-cAMP (Br-cAMP), a membrane-permeable cAMP analog, can mimic the similar effects produced by high glucose. Subsequently Br-cAMP could induce β-galactosidase (β-Gal) recombinant protein expression by 1.6-fold. Furthermore, Br-cAMP can additionally enhance the β-Gal production (from 2.8- to 4.5-fold) when CHO cells were stimulated with glycerol, thymidine, dimethyl sulfoxide, pentanoic acid, or sodium butyrate. Thus, Br-cAMP may be used as an alternative agent in promoting foreign protein expression for CHO cells. Copyright © 2017. Published by Elsevier B.V.

  6. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO; Avaliacao do efeito radiomodificador da propolis em celulas de ovario de hamster chines (CHO-K1) e em celulas tumorais de prostata (PC3), irradiadas com CO-60

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Geyza Spigoti

    2011-07-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with {sup 60}Co {gamma} radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 {mu}g/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400{mu}/ml) in PC3 cells irradiated with 5 G{gamma}. The survival curves obtained were adequately fitted by a linear-quadratic model, where the {alpha} coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 {mu}g/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data

  7. Isolation, cloning and molecular characterization of a thermotolerant ...

    African Journals Online (AJOL)

    Isolation, cloning and molecular characterization of a thermotolerant xylanase from Streptomyces sp. THW31. Thayat Sriyapai, Peechapack Somyoonsap, Supatra Areekit, Paisarn Khawsak, Arda Pakpitcharoen, Kosum Chansiri ...

  8. Understanding of decreased sialylation of Fc-fusion protein in hyperosmotic recombinant Chinese hamster ovary cell culture: N-glycosylation gene expression and N-linked glycan antennary profile.

    Science.gov (United States)

    Lee, Jong Hyun; Jeong, Yeong Ran; Kim, Yeon-Gu; Lee, Gyun Min

    2017-08-01

    To understand the effects of hyperosmolality on protein glycosylation, recombinant Chinese hamster ovary (rCHO) cells producing the Fc-fusion protein were cultivated in hyperosmolar medium resulting from adding NaCl (415 mOsm/kg). The hyperosmotic culture showed increased specific Fc-fusion protein productivity (q Fc ) but a decreased proportion of acidic isoforms and sialic acid content of the Fc-fusion protein. The intracellular and extracellular sialidase activities in the hyperosmotic cultures were similar to those in the control culture (314 mOsm/kg), indicating that reduced sialylation of Fc-fusion protein at hyperosmolality was not due to elevated sialidase activity. Expression of 52 N-glycosylation-related genes was assessed by the NanoString nCounter system, which provides a direct digital readout using custom-designed color-coded probes. After 3 days of hyperosmotic culture, nine genes (ugp, slc35a3, slc35d2, gcs1, manea, mgat2, mgat5b, b4galt3, and b4galt4) were differentially expressed over 1.5-fold of the control, and all these genes were down-regulated. N-linked glycan analysis by anion exchange and hydrophilic interaction HPLC showed that the proportion of highly sialylated (di-, tri-, tetra-) and tetra-antennary N-linked glycans was significantly decreased upon hyperosmotic culture. Addition of betaine, an osmoprotectant, to the hyperosmotic culture significantly increased the proportion of highly sialylated and tetra-antennary N-linked glycans (P ≤ 0.05), while it increased the expression of the N-glycan branching/antennary genes (mgat2 and mgat4b). Thus, decreased expression of the genes with roles in the N-glycan biosynthesis pathway correlated with reduced sialic acid content of Fc-fusion protein caused by hyperosmolar conditions. Taken together, the results obtained in this study provide a better understanding of the detrimental effects of hyperosmolality on N-glycosylation, especially sialylation, in rCHO cells. Biotechnol. Bioeng

  9. Pleurotus sajor-caju HSP100 complements a thermotolerance ...

    Indian Academy of Sciences (India)

    To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomyces cerevisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant ...

  10. Isolation and characterization of thermotolerant ethanol-fermenting ...

    African Journals Online (AJOL)

    sunny t

    2016-02-10

    Feb 10, 2016 ... ethanol fermentation ability of the isolated strains were compared with those of the K. marxianus strain DMKU 3-. 1042 as a control, which is one of the most thermotolerant and efficient strains isolated in Thailand (Limtong et al.,. 2007). MATERIALS AND METHODS. Isolation of thermotolerant yeast strains.

  11. Transport of D-[1-14C]-amino acids into Chinese hamster ovary (CHO-K1) cells: implications for use of labeled D-amino acids as molecular imaging agents

    International Nuclear Information System (INIS)

    Shikano, Naoto; Nakajima, Syuichi; Kotani, Takashi; Ogura, Masato; Sagara, Jun-ichi; Iwamura, Yukio; Yoshimoto, Mitsuyoshi; Kubota, Nobuo; Ishikawa, Nobuyoshi; Kawai, Keiichi

    2007-01-01

    Introduction: The fact that D-amino acids have been found in various tissues and are involved in various functions is a clue to how to develop new imaging agents. We examined D-amino acid transport mechanisms in Chinese hamster ovary (CHO-K1) cells because CHO-K1 cells are widely used in biomedical studies and are thought to be useful for expression of genes involved in metabolism of D-amino acids. Methods: Uptake experiments were performed. CHO-K1 cells cultured in 60-mm plastic culture dishes under ordinary culture conditions were incubated with 18.5 kBq of radiolabeled amino acid in 2 ml of phosphate-buffered-saline-based uptake solution at 37 o C. The following radiolabeled amino acid tracers were used: D-[1- 14 C]-alanine, L-[1- 14 C]-alanine, D-[1- 14 C]-serine, L-[1- 14 C]-serine, D-[1- 14 C]-methionine, L-[1- 14 C]-methionine, D-[1- 14 C]-phenylalanine, L-[1- 14 C]-phenylalanine, D-[1- 14 C]-leucine, L-[1- 14 C]-leucine, D-[1- 14 C]-valine, L-[1- 14 C]-valine, D-[1- 14 C]-tyrosine, L-[1- 14 C]-tyrosine, D-[1- 14 C]-glutamic acid, L-[1- 14 C]-glutamic acid, D-[1- 14 C]-lysine, L-[1- 14 C]-lysine, D-[1- 14 C]-arginine and L-[1- 14 C]-arginine. We tested the inhibitory effects of the following compounds (1.0 mM) on transport: 2-(methylamino)isobutyric acid (a specific inhibitor of system A, in Na + -containing uptake solution) and 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (a specific inhibitor of system L, in Na + -free uptake solution). Results: D-[1- 14 C]-methionine, D-[1- 14 C]-phenylalanine and D-[1- 14 C]-tyrosine accumulated mainly via system L. D-[1- 14 C]-alanine and D-[1- 14 C]-serine accumulated primarily via system ASC. High uptake of D-[1- 14 C]-alanine, D-[1- 14 C]-methionine, D-[1- 14 C]-phenylalanine and D-[1- 14 C]-leucine was observed. The uptake of radiolabeled serine, valine, tyrosine, glutamic acid and arginine into CHO-K1 was highly stereoselective for L-isomers. Conclusions: We observed high uptake of D-[1- 14 C]-alanine via system

  12. Biofuels. Altered sterol composition renders yeast thermotolerant

    DEFF Research Database (Denmark)

    Caspeta, Luis; Chen, Yun; Ghiaci, Payam

    2014-01-01

    Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ≥40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used...... adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ≥40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol...... desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype....

  13. Thermotolerant cyclamen with reduced acrolein and methyl vinyl ketone.

    Science.gov (United States)

    Kai, Hiroomi; Hirashima, Keita; Matsuda, Osamu; Ikegami, Hidetoshi; Winkelmann, Traud; Nakahara, Takao; Iba, Koh

    2012-06-01

    Reduced levels of trienoic fatty acids (TAs) in chloroplast membranes induce thermotolerance in several plant species, but the underlying mechanisms remain unclear. TA peroxidation in plant cell membranes generates cytotoxic, TA-derived compounds containing α,β-unsaturated carbonyl groups. The relationship between low TA levels and the amounts of cytotoxic TA-derived compounds was examined using thermotolerant transgenic cyclamen (Cyclamen persicum Mill.) with low TA contents. Changes in the levels of the cytotoxic TA-derived acrolein (ACR), methyl vinyl ketone (MVK), (E)-2-hexenal, 4-hydroxy-2-nonenal, and malondialdehyde were analysed in the leaf tissues of wild-type (WT) and thermotolerant transgenic cyclamen under heat stress. Levels of ACR and MVK in the WT increased in parallel with the occurrence of heat-induced tissue damage, whereas no such changes were observed in the thermotolerant transgenic lines. Furthermore, exogenous ACR and MVK infiltrated into leaves to concentrations similar to those observed in heat-stressed WT leaves caused similar disease symptoms. These results suggest that thermotolerance in transgenic cyclamen depends on reduced production rates of ACR and MVK under heat stress, due to the low level of TAs in these plants.

  14. Thermotolerant yeasts and application for ethanol production

    Directory of Open Access Journals (Sweden)

    To-on, N.

    2007-07-01

    Full Text Available A total of 70 thermotolerant yeast strains were isolated at 40oC from 145 samples including fruit, leaves, flowers, soils and oil-palm fruits. Six isolates showed maximum growth at 40oC within 18 h. Three isolates (MIY1, MIY48 and MIY57 were selected based on their ability to ferment glucose and sucrose rapidly (24 h and showed the maximum temperature for growth at 42oC but it was good at 40oC. MIY57 produced 4.6% (v/v ethanol at 40oC from a medium containing 15% glucose. The optimum cultivation conditions for growth and ethanol production of MIY57 was 5% inoculum into the fermentation medium containing 15% glucose and 1% yeast extract with initial pH of 4.5 on a shaking incubator at 150 rpm at 40oC. MIY57, under these conditions, produced maximum ethanol of 5.0% (v/v after 48 h incubation while S. cerevisiae TISTR 5048 produced only 3.7% (v/v. Maximum cell dry weight was 7.2 g/L (at 18 h, again much higher than that of S. cerevisiae TISTR 5048 (4.1 g/L. Based on morphological, physiological and molecular studies, this strain (MIY57 was identified as Saccharomyces cerevisiae.

  15. High salinity conveys thermotolerance in the coral model Aiptasia

    KAUST Repository

    Gegner, Hagen M.

    2017-12-15

    The endosymbiosis between dinoflagellate algae of the genus Symbiodinium and stony corals provides the foundation of coral reef ecosystems. Coral bleaching, the expulsion of endosymbionts from the coral host tissue as a consequence of heat or light stress, poses a threat to reef ecosystem functioning on a global scale. Hence, a better understanding of the factors contributing to heat stress susceptibility and tolerance is needed. In this regard, some of the most thermotolerant corals also live in particularly saline habitats, but possible effects of high salinity on thermotolerance in corals are anecdotal. Here we test the hypothesis that high salinity may lead to increased thermotolerance. We conducted a heat stress experiment at low, intermediate, and high salinities using a set of host-endosymbiont combinations of the coral model Aiptasia. As expected, all host-endosymbiont combinations showed reduced photosynthetic efficiency and endosymbiont loss during heat stress, but the severity of bleaching was significantly reduced with increasing salinities for one of the host-endosymbiont combinations. Our results show that higher salinities can convey increased thermotolerance in Aiptasia, although this effect seems to be dependent on the particular host strain and/or associated symbiont type. This finding may help explain the extraordinarily high thermotolerance of corals in high salinity environments such as the Red Sea and the Persian/Arabian Gulf and provides novel insight regarding factors that contribute to thermotolerance. Since our results are based on a salinity effect in symbiotic sea anemones, it remains to be determined whether this salinity effect can also be observed in stony corals.

  16. Elk3 from hamster-a ternary complex factor with strong transcriptional repressor activity

    DEFF Research Database (Denmark)

    Hjortoe, G.M.; Weilguny, D.; Willumsen, Berthe Marie

    2005-01-01

    the transcription of genes that are activated during entry into G1. We have isolated the Cricetulus griseus Elk3 gene from the Chinese hamster ovary (CHO) cell line and investigated the transcriptional potential of this factor. Transient transfections revealed that, in addition to its regulation of the c......-fos promoter, Elk3 from CHO cells seems to inhibit other promoters controlling expression of proteins involved in G1/S phase progression; Cyclin D1 and DHFR. As has been described for the Elk3 homologs Net (Mouse) and Sap-2 (Human), the results of the present study further indicate that hamster Elk3...

  17. Effect of thermotolerance on thermal radiosensitization in hepatoma cells

    International Nuclear Information System (INIS)

    van Rijn, J.; van den Berg, J.; Schamhart, D.H.J.; van Wijk, R.

    1984-01-01

    The interaction between hyperthermia and X irradiation was determined in cultured Reuber H35 hepatoma cells with different states of thermosensitivity. Incubation at 41 0 C followed by 4-Gy X rays resulted after 2 hr in a stabilization of cell survival for heat or heat plus X rays, with a maximum synergism factor of 1.6. Thermotolerance did not develop during incubation at 41.7 or 42.5 0 C. When heat treatment of cells was followed by irradiation, the synergism factor for thermal radiosensitization increased with both the amount of thermal cell killing and the amount of X-ray cell killing; the influence of thermal exposure on the synergism factor was greater than that of the X-ray dose. Cells were made thermotolerant either by incubation at 42.5 0 C for 30 or 60 min followed by an interval at 37 0 C, or by continuous incubation at 41 0 C. In both cases thermotolerance was measured by incubation at 42.5 0 C. No difference was observed between the maximum thermotolerance achieved with both methods. When cells were irradiated in addition to the second heat treatment, thermal radiosensitization was strongly reduced concomitant with the decreased sensitivity to killing by heat

  18. The prevalence of thermotolerant Campylobacter species in food ...

    African Journals Online (AJOL)

    Background: Thermotolerant Campylobacter spp. is known to occur in the intestinal systems of a wide variety of domestic and wild animals. Although Campylobacter jejuni and Campylobacter coli cause acute diarrhoeal diseases in humans worldwide, they mostly manifest themselves in an apparently healthy carrier state in ...

  19. Polyphasic identification of a new thermotolerant species of lactic ...

    African Journals Online (AJOL)

    Two thermotolerant and desiccation tolerant lactic acid bacteria (TDLAB) were pointed out from twenty isolated strains from soils and dried chicken faeces. Samples were collected in poultry farms in the vicinity of Dakar, Senegal (West Africa). The two new isolates were called Sp.4 (Sp.4=CWBI-B534=LMG7278) and Sp.20 ...

  20. Induction of thermotolerance through heat acclimation and salicylic ...

    African Journals Online (AJOL)

    High temperature stress is the second most important stress, which can strike crop plants at any time and impose severe limitations on crop growth and development. Developing crop plants with improved thermotolerance can mitigate the adverse effects of heat stress. However, a thorough understanding of physiological ...

  1. The prevalence of thermotolerant Campylobacter species in food ...

    African Journals Online (AJOL)

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    Abstract. Background: Thermotolerant Campylobacter spp. is known to occur in the intestinal systems of a wide variety of domestic and wild animals. Although Campylobacter jejuni and Campylobacter coli cause acute diarrhoeal diseases in humans worldwide, they mostly manifest themselves in an apparently healthy ...

  2. Isolation and characterization of thermotolerant ethanol-fermenting ...

    African Journals Online (AJOL)

    Thermotolerant yeasts, which are expected to be applicable for high-temperature fermentation as an economical process, were isolated from four provinces in Laos. Of these yeasts, five isolates exhibited stronger fermentation abilities in a 16% sugars-containing medium of glucose, sucrose, sugarcane or molasses at 40°C ...

  3. Leaf thermotolerance in dry tropical forest tree species: relationships with leaf traits and effects of drought.

    Science.gov (United States)

    Sastry, Aniruddh; Guha, Anirban; Barua, Deepak

    2018-02-01

    Understanding how tropical trees will respond to extreme temperatures and drought is essential to predict how future increases in the severity, frequency and duration of extreme climatic events will affect tropical systems. In this study, we investigated leaf thermotolerance by quantifying the temperatures that resulted in a 50 % decrease in photosystem II function (T 50 ) in experimentally grown saplings of 12 tree species from a seasonally dry tropical forest. We examined the relationship of thermotolerance with leaf functional traits and photosynthetic rates. Additionally, we tested how water limitation altered thermotolerance within species, and examined the relationship between thermotolerance and drought tolerance among species. Thermotolerance ranged from 44.5 to 48.1 °C in the least and most thermotolerant species, respectively. The observed variation in thermotolerance indicates that the upper limits of leaf function are critically close to maximum temperatures in this region, and that these species will be vulnerable to, and differentially affected by, future warming. Drought increased temperature tolerance, and species that were more drought tolerant were also more thermotolerant. Importantly, thermotolerance was positively related to the key leaf functional trait-leaf mass per area (LMA), and congruent with this, negatively related to photosynthetic rates. These results indicate that more productive species with lower LMA and higher photosynthetic rates may be more vulnerable to heat and drought stress, and more likely to be negatively affected by future increases in extreme climatic events.

  4. Expression and thermotolerance of calreticulin during pollen development in tobacco

    Czech Academy of Sciences Publication Activity Database

    Hrubá, Petra; Honys, David; Tupý, Jaroslav

    2005-01-01

    Roč. 18, č. 3 (2005), s. 143-148 ISSN 0934-0882 R&D Projects: GA ČR GP522/02/D075; GA MŠk LZ1K03018; GA AV ČR KJB6038409 Institutional research plan: CEZ:AV0Z50380511 Keywords : tobacco * pollen development * thermotolerance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.278, year: 2005

  5. Thermotolerant fermenting yeasts for simultaneous saccharification fermentation of lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Jairam Choudhary

    2016-05-01

    Full Text Available Lignocellulosic biomass is the most abundant renewable source of energy that has been widely explored as second-generation biofuel feedstock. Despite more than four decades of research, the process of ethanol production from lignocellulosic (LC biomass remains economically unfeasible. This is due to the high cost of enzymes, end-product inhibition of enzymes, and the need for cost-intensive inputs associated with a separate hydrolysis and fermentation (SHF process. Thermotolerant yeast strains that can undergo fermentation at temperatures above 40°C are suitable alternatives for developing the simultaneous saccharification and fermentation (SSF process to overcome the limitations of SHF. This review describes the various approaches to screen and develop thermotolerant yeasts via genetic and metabolic engineering. The advantages and limitations of SSF at high temperatures are also discussed. A critical insight into the effect of high temperatures on yeast morphology and physiology is also included. This can improve our understanding of the development of thermotolerant yeast amenable to the SSF process to make LC ethanol production commercially viable.

  6. Sensitization to hyperthermia (450C) of normal and thermotolerant CHO cells by anisotonic media

    International Nuclear Information System (INIS)

    Henle, K.J.; Dethlefsen, L.A.

    1979-01-01

    Asynchronous CHO cells heated in the presence of hypertonic medium (600 mosM) showed an increased sensitivity to 45 0 C hyperthermia and the extent varied as a function of the time of heating with respect to the hypertonic shock. Hypotonic medium (150 mosM) also reduced n without significantly reducing the D 0 , and in contrast to hypertonic medium, this effect was independent of the temporal relationship between the osmotic shock and heating. Sensitization of non-thermotolerant cells by hypotonic shock was possible but only when cells were heated immediately upon return to isotonic medium following a one-hour equilibration in hypotonic medium. Thermotolerant CHO cells were sensitized slightly more than non-thermotolerant cells (a factor of 2.2 versus 1.7) when heated immediately after the hypertonic shock, and heat conditioning in the presence of hypertonic medium also sensitized the cells but not as dramatically as when thermotolerant cells were reheated in the presence of hypertonic medium (thermotolerant control D 0 = 16.8 +- 1.3 min versus 11.4 +- 2.4 and 7.8 +- 0.2, respectively for the hypertonic studies). In contrast to the studies with non-thermotolerant cells, thermotolerant cells were sensitized when heated immediately after the hypotonic shock (D 0 = 10.7 +- 1.6 min). Also, incubating the heat-conditioned cells in hypertonic medium impaired the development of thermotolerance. These data suggest that: (1) anisotonic-media reduction of the extrapolation number is associated with osmotically induced membrane stress. (2) The difference in sensitization between thermotolerant and non-thermotolerant cells is apparently one of quantity and not quality, and (3) in contrast to bacterial data, these mammalian data do not suggest a possible role for the altered intracellular ion concentrations per se in the development of thermotolerance. (author)

  7. Acquired Thermotolerance and Heat Shock Proteins in Thermophiles from the Three Phylogenetic Domains

    DEFF Research Database (Denmark)

    Trent, Jonathan D.; Gabrielsen, Mette; Jensen, Bo

    1994-01-01

    Thermophilic organisms from each of the three phylogenetic domains (Bacteria, Archaea, and Eucarya) acquired thermotolerance after heat shock. Bacillus caldolyticus grown at 60 degrees C and heat shocked at 69 degrees C for 10 min showed thermotolerance at 74 degrees C, Sulfolobus shibatae grown...

  8. Photosynthetic thermotolerance of woody savanna species in China is correlated with leaf life span.

    NARCIS (Netherlands)

    Zhang, J.L.; Poorter, L.; Hao, G.Y.; Cao, K.F.

    2012-01-01

    Background and Aims Photosynthetic thermotolerance (PT) is important for plant survival in tropical and sub-tropical savannas. However, little is known about thermotolerance of tropical and sub-tropical wild plants and its association with leaf phenology and persistence. Longer-lived leaves of

  9. Complete genome sequence of the thermotolerant foodborne pathogen Salmonella enterica serovar Senftenberg ATCC 43845 and phylogenetic analysis of loci encoding thermotolerance

    Science.gov (United States)

    Introduction: Previous studies in Cronobacter sakazakii, Klebsiella spp., and Escherichia coli have identified a genomic island that confers thermotolerance to its hosts. This island has recently been identified in Salmonella enterica serovar Senfentenberg ATCC 43845, a historically important, heat ...

  10. Polymyopathy in a Syrian golden hamster

    NARCIS (Netherlands)

    Wijnands, M.V.W.; Woutersen, R.A.

    1996-01-01

    A Syrian golden hamster suffered from general swelling of skeletal muscles. At microscopical observation the muscle tissue exhibited degeneration and necrosis, as well as regenerative features. The inflammatory response was very slight. The histopathological lesions were diagnosed as polymyopathy.

  11. Induction of lyme arthritis in LSH hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, J.L.; Schell, R.F.; Hejka, A.; England, D.M.; Konick, L.

    1988-09-01

    In studies of experimental Lyme disease, a major obstacle has been the unavailability of a suitable animal model. We found that irradiated LSH/Ss Lak hamsters developed arthritis after injection of Borrelia burgdorferi in the hind paws. When nonirradiated hamsters were injected in the hind paws with B. burgdorferi, acute transient synovitis was present. A diffuse neutrophilic infiltrate involved the synovia and periarticular structures. The inflammation was associated with edema, hyperemia, and granulation tissue. Numerous spirochetes were seen in the synovial and subsynovial tissues. The histopathologic changes were enhanced in irradiated hamsters. The onset and duration of the induced swelling were dependent on the dose of radiation and the inoculum of spirochetes. Inoculation of irradiated hamsters with Formalin-killed spirochetes or medium in which B. burgdorferi had grown for 7 days failed to induce swelling. This animal model should prove useful for studies of the immune response to B. burgdorferi and the pathogenesis of Lyme arthritis.

  12. Obesity without overeating in golden hamsters.

    Science.gov (United States)

    Wade, G N

    1982-10-01

    When male golden hamsters were switched from a diet of Purina rodent chow to a calorically-dense high-fat diet or were given ad lib access to a 32% sucrose solution in addition to chow, they adjusted their food intakes rapidly (within 24 hr) and did not overeat. Nevertheless, the fat-fed hamsters tripled their rate of weight gain and nearly doubled their carcass fat content after one month on the diet. Resting oxygen consumption (animals awake but quite) was significantly lower in fat-fed animals than in chow-fed controls. Sucrose feeding had no effect on food intake, body weight gain, carcass composition or oxygen consumption. Thus, whereas rats exhibit dietary obesity in spite of increases in energy expenditure (diet-induced thermogenesis), fat-fed hamsters seem to become obese because of decreases in energy expenditure. However, although actual energy expenditure is reduced, fat-fed hamsters exhibit an enhanced thermogenic capacity. Interscapular brown adipose tissue mass, protein content, and DNA content as well as norepinephrine-stimulated oxygen consumption were all significantly elevated in fat-fed hamsters. The significance of these concurrent diet-induced decreases in energy expenditure and increases in thermogenic capacity is not clear, but they could be of some value in preparing the hamster for winter.

  13. Oxidative stress and antioxidant response in a thermotolerant yeast.

    Science.gov (United States)

    Mejía-Barajas, Jorge A; Montoya-Pérez, Rocío; Salgado-Garciglia, Rafael; Aguilera-Aguirre, Leopoldo; Cortés-Rojo, Christian; Mejía-Zepeda, Ricardo; Arellano-Plaza, Melchor; Saavedra-Molina, Alfredo

    Stress tolerance is a key attribute that must be considered when using yeast cells for industrial applications. High temperature is one factor that can cause stress in yeast. High environmental temperature in particular may exert a natural selection pressure to evolve yeasts into thermotolerant strains. In the present study, three yeasts (Saccharomyces cerevisiae, MC4, and Kluyveromyces marxianus, OFF1 and SLP1) isolated from hot environments were exposed to increased temperatures and were then compared with a laboratory yeast strain. Their resistance to high temperature, oxidative stress, and antioxidant response were evaluated, along with the fatty acid composition of their cell membranes. The SLP1 strain showed a higher specific growth rate, biomass yield, and biomass volumetric productivity while also showing lower duplication time, reactive oxygen species (ROS) production, and lipid peroxidation. In addition, the SLP1 strain demonstrated more catalase activity after temperature was increased, and this strain also showed membranes enriched in saturated fatty acids. It is concluded that the SLP1 yeast strain is a thermotolerant yeast with less oxidative stress and a greater antioxidant response. Therefore, this strain could be used for fermentation at high temperatures. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  14. Oxidative stress and antioxidant response in a thermotolerant yeast

    Directory of Open Access Journals (Sweden)

    Jorge A. Mejía-Barajas

    Full Text Available Abstract Stress tolerance is a key attribute that must be considered when using yeast cells for industrial applications. High temperature is one factor that can cause stress in yeast. High environmental temperature in particular may exert a natural selection pressure to evolve yeasts into thermotolerant strains. In the present study, three yeasts (Saccharomyces cerevisiae, MC4, and Kluyveromyces marxianus, OFF1 and SLP1 isolated from hot environments were exposed to increased temperatures and were then compared with a laboratory yeast strain. Their resistance to high temperature, oxidative stress, and antioxidant response were evaluated, along with the fatty acid composition of their cell membranes. The SLP1 strain showed a higher specific growth rate, biomass yield, and biomass volumetric productivity while also showing lower duplication time, reactive oxygen species (ROS production, and lipid peroxidation. In addition, the SLP1 strain demonstrated more catalase activity after temperature was increased, and this strain also showed membranes enriched in saturated fatty acids. It is concluded that the SLP1 yeast strain is a thermotolerant yeast with less oxidative stress and a greater antioxidant response. Therefore, this strain could be used for fermentation at high temperatures.

  15. Development of novel DNA markers for genetic analysis of grey hamsters by cross-species amplification of microsatellites.

    Science.gov (United States)

    Wang, C; Zhang, S J; Du, X Y; Xu, Y M; Huo, X Y; Liao, L F; Chen, Z W

    2015-11-13

    The grey hamster has been used in biomedical research for decades. However, effective molecular methods for evaluating the genetic structure of this species are lacking, which hinders its wider usage. In this study, we employed cross-amplification of microsatellite loci of species within the same genus by polymerase chain reaction. Loci screened included 107 from the Mongolian gerbil (MG) and 60 from the Chinese hamster (CH); of these, 15 polymorphic loci were identified for the grey hamster. Of the 167 loci screened, 95 (56.9%) with clear bands on agarose gel were initially identified. After sequencing, 74 (77.9%) of these matched the criteria for microsatellite characteristics, including 41 from MG and 33 from CH. Lastly, 15 (20.3%) loci with more than two alleles for each locus were identified through capillary electrophoresis scanning. To justify the applicability of the 15 grey hamster loci, genetic indexes of grey hamsters were evaluated using 46 generations of outbred stock, established 20 years ago, from Xinjiang, China. Mean effective allele numbers and expected heterozygosity of stock were as low as, respectively, 1.2 and 0.14; these were 2.8 and 4.0 times inferior, respectively, to wild grey hamsters. This finding suggests that the genetic structure of the stock-bred population is too weak to resist artificial and natural selection, mutation and genetic drifting. In conclusion, we have developed de novo microsatellite markers for genetic analysis of the grey hamster, providing data and methodology for the enrichment of a genetic library for this species.

  16. The structural-functional organization of thermotolerant complexes of actinomycetes in desert and volcanic soils

    Science.gov (United States)

    Zenova, G. M.; Kurapova, A. I.; Lysenko, A. M.; Zvyagintsev, D. G.

    2009-05-01

    It has been found that the number of thermotolerant actinomycetes in strongly heated soils of deserts and volcanic regions is comparable to or exceeds the number of mesophilic actinomycetes. Among the latter group, streptomyces usually predominate; among thermotolerant actinomycetes, representatives of the Micromonospora, Streptosporangium, Actinomadura, Saccharopolyspora, Microtetraspora, and Microbispora genera are identified. Thermotolerant actinomycetes display the full cycle of their development in these soils. The method of fluorescent in situ hybridization has made it possible to determine that mycelial forms predominate among the metabolically active representatives of Actinobacteria; their portion increases with the rise in the temperature of soil incubation.

  17. Thermotolerance-induced goblet cell activity confers protection in post-operative gut barrier dysfunction.

    LENUS (Irish Health Repository)

    Ali, Rohana

    2009-06-01

    There is evidence that some level of protection against the adverse sequelae of surgery is provided by induction of thermotolerance; this protective effect was explored by study of several indicators of bowel wall damage in animals exposed to surgical insults. It has been argued that the mechanism of the protective effect of thermotolerance involves heat shock proteins (HSPs). We hypothesized that the protective effect of thermotolerance may be due in part to changes in the bowel wall itself, and we investigated this hypothesis in an experimental rat model.

  18. Cystolithiasis in a Syrian hamster: a different outcome | Petrini ...

    African Journals Online (AJOL)

    Considering the positive outcome and the beneficial properties of palmitoylethanolamide, glucosamine, and hesperidin, these nutritional elements in Syrian hamsters, are recommended to reduce recurrence after surgical treatment of urolithiasis. Keywords: Glucosamine, Hamster, Hesperidin, PEA, Urolithiasis ...

  19. Production and purification of polyclonal anti-hamster ...

    African Journals Online (AJOL)

    . ... IgG showed high titer and high specificity in the designed ELISA. Purified antibody and its conjugation with HRP are used in research and diagnosis of hamster disease. Key words: Production, purification, hamster immunoglobulins.

  20. Thermotolerance and Human Performance: Role of Heat Shock Proteins

    Science.gov (United States)

    2009-10-01

    stress response, can be achieved with mild pretreatment and Hsp responses correlate with this tolerance. In the developing embryo , the heat shock...or other stressors without any negative impacts in the developing embryos is largely unknown. Significant research has focused on the role, induction...rats, hamsters, guinea pigs, rabbits, sheep , pigs, and monkeys (Edwards et al 2003). However, the type and severity of the fetal defects were dependent

  1. Histopathology of Lyme arthritis in LSH hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Hejka, A.; Schmitz, J.L.; England, D.M.; Callister, S.M.; Schell, R.F.

    1989-05-01

    The authors studied the histopathologic evolution of arthritis in nonirradiated and irradiated hamsters infected with Borrelia burgdorferi. Nonirradiated hamsters injected in the hind paws with B. burgdorferi developed an acute inflammatory reaction involving the synovium, periarticular soft tissues, and dermis. This acute inflammatory reaction was short-lived and was replaced by a mild chronic synovitis as the number of detectable spirochetes in the synovium, periarticular soft tissues, and perineurovascular areas diminished. Exposing hamsters to radiation before inoculation with B. burgdorferi exacerbated and prolonged the acute inflammatory phase. Spirochetes also persisted longer in the periarticular soft tissues. A major histopathologic finding was destructive and erosive bone changes of the hind paws, which resulted in deformation of the joints. These studies should be helpful in defining the immune mechanism participating in the onset, progression, and resolution of Lyme arthritis.

  2. The defect in the AT-like hamster cell mutants is complemented by mouse chromosome 9 but not by any of the human chromosomes

    NARCIS (Netherlands)

    W. Jongmans; G. Verhaegh (Gerald); N.G.J. Jaspers (Nicolaas); P. Demant (Peter); A.T. Natarajan; Y. Shiloh (Yosef); M. Oshimura (Mitsuo); E.J. Stanbridge (Eric); R.S. Athwal (Raghbir); A.P. Cuthbert (Andrew); R.F. Newbold (Robert); P.H.M. Lohmann (Paul); M.Z. Zdzienicka (Malgorzata)

    1996-01-01

    textabstractX-ray-sensitive Chinese hamster V79 cells mutants, V-C4, V-E5 and V-G8, show an abnormal response to X-ray-induced DNA damage. Like ataxia telangiectasia (AT) cells, they display increased cell killing, chromosomal instability and a diminished inhibition of DNA synthesis following

  3. Human risk from thermotolerant Campylobacter on broiler meat in Denmark

    DEFF Research Database (Denmark)

    Boysen, Louise; Nauta, Maarten; Ribeiro Duarte, Ana Sofia

    2013-01-01

    This paper describes a new approach by which changes over time in the relative risk of human campylobacteriosis from broiler meat are evaluated through quantitative microbiological risk assessment modelling. Danish surveillance data collected at retail from 2001 to 2010 on numbers of thermotolerant...... Campylobacter spp. on Danish produced and imported chilled and frozen broiler meat were the basis for the investigation. The aim was to explore if the risk from the different meat categories had changed over time as a consequence of implemented intervention strategies. The results showed a slight decrease from...... 2005 to 2008 in the human risk from Danish produced broiler meat, and a decrease from 2005 to 2010 in the risk from imported chilled meat. This risk reduction coincides with control measures implemented to reduce Campylobacter in Danish and imported chilled broiler meat. The human risk...

  4. Thermotolerance and protein glycosylation: Inhibition studies with sodium fluoride, azauridine and tunicamycin

    International Nuclear Information System (INIS)

    Bursey, D.L.; Henle, K.J.; Nagle, W.A.; Moss, A.J.

    1987-01-01

    The glycosylation hypothesis predicts increased incorporation of monosaccharides into 0-linked glycoproteins during thermotolerance development and inhibition of thermotolerance when this process is blocked. Specific inhibitors of 0-linked glycosylation are not available. The authors examined the effect of non-specific inhibition of glycosylation on thermotolerance development by: 1. restriction of both exogenous sugars and endogeneous sugar synthesis with NaF to block glycolysis while providing L-glutamine as a substrate for ATP synthesis in the TCA cycle; or 2. inhibition of UDP-sugar synthesis using azauridine and tunicamycin. Inhibitors were added to cell cultures after heat conditioning (10 min, 45 0 ) and removed after 6 hr prior to 45 0 -test heating. Sugar deprivation was achieved with 10mM NaF in glucose-free EBSS, supplemented with 2mM L-glutamine. Synthesis of UDP-sugars was inhibited with 1mM azauridine + 1μg/ml tunicamycin. Thermotolerance development was inhibited 87% by NaF/glutamine and 47% by azauridine/tunicamycin. For example, the D/sub o/ of the thermotolerant cells was 42.5 min (control D/sub o/ = 3 min), but only 5.5 min with inhibition by the NaF solution. These results support the absolute requirement of sugar precursors for thermotolerance development as predicted by the glycosylation hypothesis

  5. Production of thermotolerant entomopathogenic Isaria fumosorosea SFP-198 conidia in corn-corn oil mixture.

    Science.gov (United States)

    Kim, Jae Su; Je, Yeon Ho; Roh, Jong Yul

    2010-04-01

    Low thermotolerance of entomopathogenic fungi is a major impediment to long-term storage and effective application of these biopesticides under seasonal high temperatures. The effects of high temperatures on the viability of an entomopathogenic fungus, Isaria fumosorosea SFP-198 (KCTC 0499BP), produced on different substrates amended with various additives were explored. Ground corn was found to be superior in producing the most thermotolerant conidia compared to yellow soybean, red kidney bean, and rice in a polyethylene bag production system. Using ground corn mixed with corn oil as a substrate resulted in only 7% reduction in germination compared to ground corn alone (67% reduction) after exposure of conidia to 50 degrees C for 2 h. Corn oil as an additive for ground corn was followed by inorganic salts (KCl and NaCl), carbohydrates (sucrose and dextrin), a sugar alcohol (sorbitol), and plant oils (soybean oil and cotton seed oil) in ability to improve conidial thermotolerance. Unsaturated fatty acids, such as linoleic acid and oleic acid, the main components of corn oil, served as effective additives for conidial thermotolerance in a dosage-dependent manner, possibly explaining the improvement by corn oil. This finding suggests that the corn-corn oil mixture can be used to produce highly thermotolerant SFP-198 conidia and provides the relation of unsaturated fatty acids as substrates with conidial thermotolerance.

  6. Studies on adaptive responses in Chinese hamster cells

    International Nuclear Information System (INIS)

    Michelin, S.C.; Perez, M.R. Del; Dubner, D.; Gisone, P.A.

    1997-01-01

    For many years the possibility has been considered of low doses of radiation inducing adaptive responses in cells and organisms against the mutagenic effects of radiation. Currently, a number of experimental data appraise the existence of an adaptive response that is characterized by a decrease of radiation induced genetic damages. The understanding of the molecular mechanism involved in this phenomenon permits to estimate the effects and risks of low dose exposure. In this work, preliminary results of studies on the induction of adaptive response in cells subjected to different doses of ionizing radiation are presented

  7. Synthesis of human prolactin in Chinese hamster ovary (CHO) cells

    International Nuclear Information System (INIS)

    Soares, Carlos Roberto Jorge

    2000-01-01

    Three different eukaryotic expression vectors, based on the same selectable gene marker (dhfr), have been used for dhf- CHO cells transfection to rapidly isolate stable cell lines capable of secreting high levels of recombinant human prolactin (rec-hPRL). Two vectors, one codifying a human prolactin (p658-hPRL) and the other a tag-prolactin (p658-tagPRL), contain the complete hepatitis B virus-X (HBV-X) gene coding for a viral transactivator and a sequence derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF) that mediates selective dhfr mRNA degradation. These vectors have the advantage of rapidly obtaining stable cell lines without methotrexate amplification. The highest secretion obtained by these vectors was of approximately 10 μg hPRU10 6 cells/day. The other vector (pEDdc-hPRL) is based on a dicistronic expression system, containing an internal ribosome entry site isolated from the encephalomyocarditis (EMC) virus. This vector before amplification provided secretion levels at least 10 fold lower than that obtained with the other two vectors. However, after three steps of methotrexate amplification, it provided some clones able to secrete up to 30 μg hPRU10 6 cells/day. This is the first report describing the production and purification of rec-hPRL from CHO cells, obtaining secretion levels with both vectors higher than those reported so far for this hormone in other eukaryotic systems. CHO-derived rec-hPRL contained approximately 10 % of the glycosylated form, a value that is consistent with results reported for hPRL purified from the pituitary or from transformed murine C-127 cells. CHO-derived rec-hPRL was purified with good yield, obtaining also a good resolution between non-glycosylated and glycosylated prolactin. The latter, when its potency was determined via an in vitro bioassay, presented a 47 % lower bioactivity. A qualitative and quantitative analysis of these forms was also possible thanks to the setting up of a reversed-phase HPLC technique, for the first time applied to this hormone. A pilot production in a hollow fiber bioreactor provided a highly concentrated medium, though with the presence of considerable amounts of hPRL 11-199 fragments, apparently the result of a proteolytic process. (author)

  8. Contamination of genetically engineered Chinese hamster ovary cells.

    Science.gov (United States)

    Burstyn, D G

    1996-01-01

    In late 1988, during production of a recombinant protein for phase I clinical trials, a failure of the cell culture production system occurred due to contamination of the cells by an orbivirus [1]. The incident occurred at Bioferon GmbH & Co, Laupheim, Germany, a joint venture of Biogen, Inc., Cambridge, MA, and Dr. Renstschler Arzneimittel GmbH & Co (Bioferon is currently a wholly owned subsidiary of Rentschler and is now known as Dr. Rentschler Biotechnologie GmbH). The investigation into, and the subsequent response to, the infection can be divided into three stages: Stage I, Investigation and initial response; Stage II, Secondary response; and Stage III: Continuing response.

  9. DNA repair in human xeroderma pigmentosum and chinese hamster cells

    International Nuclear Information System (INIS)

    Zelle, B.

    1980-01-01

    The investigations described were performed to study the genetic heterogeneity of excision repair-deficient XP (xeroderma pigmentosum) strains and the biochemical defects in their repair processes after irradiation with ultraviolet radiation. (Auth.)

  10. Nipah virus transmission in a hamster model.

    Directory of Open Access Journals (Sweden)

    Emmie de Wit

    2011-12-01

    Full Text Available Based on epidemiological data, it is believed that human-to-human transmission plays an important role in Nipah virus outbreaks. No experimental data are currently available on the potential routes of human-to-human transmission of Nipah virus. In a first dose-finding experiment in Syrian hamsters, it was shown that Nipah virus was predominantly shed via the respiratory tract within nasal and oropharyngeal secretions. Although Nipah viral RNA was detected in urogenital and rectal swabs, no infectious virus was recovered from these samples, suggesting no viable virus was shed via these routes. In addition, hamsters inoculated with high doses shed significantly higher amounts of viable Nipah virus particles in comparison with hamsters infected with lower inoculum doses. Using the highest inoculum dose, three potential routes of Nipah virus transmission were investigated in the hamster model: transmission via fomites, transmission via direct contact and transmission via aerosols. It was demonstrated that Nipah virus is transmitted efficiently via direct contact and inefficiently via fomites, but not via aerosols. These findings are in line with epidemiological data which suggest that direct contact with nasal and oropharyngeal secretions of Nipah virus infected individuals resulted in greater risk of Nipah virus infection. The data provide new and much-needed insights into the modes and efficiency of Nipah virus transmission and have important public health implications with regards to the risk assessment and management of future Nipah virus outbreaks.

  11. Nipah Virus Transmission in a Hamster Model

    Science.gov (United States)

    de Wit, Emmie; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J.

    2011-01-01

    Based on epidemiological data, it is believed that human-to-human transmission plays an important role in Nipah virus outbreaks. No experimental data are currently available on the potential routes of human-to-human transmission of Nipah virus. In a first dose-finding experiment in Syrian hamsters, it was shown that Nipah virus was predominantly shed via the respiratory tract within nasal and oropharyngeal secretions. Although Nipah viral RNA was detected in urogenital and rectal swabs, no infectious virus was recovered from these samples, suggesting no viable virus was shed via these routes. In addition, hamsters inoculated with high doses shed significantly higher amounts of viable Nipah virus particles in comparison with hamsters infected with lower inoculum doses. Using the highest inoculum dose, three potential routes of Nipah virus transmission were investigated in the hamster model: transmission via fomites, transmission via direct contact and transmission via aerosols. It was demonstrated that Nipah virus is transmitted efficiently via direct contact and inefficiently via fomites, but not via aerosols. These findings are in line with epidemiological data which suggest that direct contact with nasal and oropharyngeal secretions of Nipah virus infected individuals resulted in greater risk of Nipah virus infection. The data provide new and much-needed insights into the modes and efficiency of Nipah virus transmission and have important public health implications with regards to the risk assessment and management of future Nipah virus outbreaks. PMID:22180802

  12. Effect of mebendazole on fibrosarcoma in hamsters

    African Journals Online (AJOL)

    1Department of Histology and Embryology, 2Department of Pharmacy, 3Department of Pharmacology, Toxicology and Clinical. Pharmacology ... Purpose: To investigate the effect of mebendazole on an in vivo solid tumor model of fibrosarcoma in hamsters. ..... cancer [16] and one case report of colon cancer. [14] can be ...

  13. Thermotolerant Yeasts for Bioethanol Production Using Lignocellulosic Substrates

    Science.gov (United States)

    Pasha, Chand; Rao, L. Venkateswar

    glucose without a physical and chemical pre-treatment. The pre-treatment processes normally applied on the different substrates are acidic hydrolysis, steam explosion and wet oxidation. A problem for most pretreatment methods is the generation of compounds that are inhibitory towards the fermenting microorganisms, primarily phenols. Degradation products that could have inhibitory action in later fermentation steps are avoided during pre-treatment by wet oxidation. Followed by pre treatment, hydrolysed with enzymes known as cellulases and hemicellulases, which hydrolyse cellulose and hemicellulose respectively. The production of bioethanol requires two steps, fermentation and distillation. Practically all ethanol fermentation is still based on Saccharomyces cerevisiae . The fermentation using thermotolerant yeasts has more advantageous in that they have faster fermentation rates, avoid the cooling costs, and decrease the over all fermentation costs, so that ethanol can be made available at cheaper rates. In addition they can be used for efficient simultaneous saccharification and fermentation of cellulose by cellulases because the temperature optimum of cellulase enzymes (about 40 ° C to 45 ° C) is close to the fermentation temperature of thermotolerant yeasts. Hence selection and improvement of thermotolerant yeasts for bioconversion of lignocellulosic substrates is very useful.

  14. The Metabolic Basis of Pollen Thermo-Tolerance: Perspectives for Breeding

    Directory of Open Access Journals (Sweden)

    Marine J. Paupière

    2014-09-01

    Full Text Available Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1–3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed.

  15. Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae

    Science.gov (United States)

    Bisschops, Markus M.; Vos, Tim; Martínez-Moreno, Rubén; Cortés, Pilar T.; Pronk, Jack T.; Daran-Lapujade, Pascale

    2015-01-01

    Stationary-phase (SP) batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability. PMID:28357268

  16. Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Markus M.M. Bisschops

    2015-10-01

    Full Text Available Stationary-phase (SP batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability.

  17. Thermotolerance in preirradiated intestine and its influence on time-temperature relationships

    International Nuclear Information System (INIS)

    Hume, S.P.; Marigold, J.C.; Manjil, L.G.

    1988-01-01

    The crypt compartment of mouse jejunum showed a transient increase in thermal susceptibility approximately 10 days after moderate X-ray doses to the abdomen (9-10 Gy). The increase in response was manifest as an increase in slope of the crypt dose-response curve but was limited to temperatures below 43 0 C. As a result, the 43 0 C inflexion in the Arrhenius plot (the relationship between treatment time and temperature) for thermal sensitivity of crypts was eliminated in preirradiated tissue, and the curve became monophasic over the range 42.0-44.5 0 C. At temperatures below 42 0 C, the curve again deviated. At supranormal temperatures of 42 0 C and below, the durations of hyperthermia needed for measurable effect were sufficient to allow thermotolerance to be expressed within the heating period. Neither the threshold heating times nor this thermotolerance were affected by prior irradiation. In the temperature range 42-43 0 C, an earlier development of thermotolerance could be demonstrated in control tissue by challenging with an acute high-temperature heat treatment. This thermotolerance was eliminated in preirradiated tissue, resulting in the apparent increase in sensitivity. The findings support the view that the complex nature of the time-temperature relationship seen in normal tissue in vivo is a manifestation of the ability of the tissue to progressively acquire a thermotolerant state during treatment at temperatures below approximately 43 0 C, so that the intrinsic sensitivity is modulated while being assessed

  18. Robustness promotes evolvability of thermotolerance in an RNA virus

    Directory of Open Access Journals (Sweden)

    Turner Paul E

    2008-08-01

    Full Text Available Abstract Background The ability for an evolving population to adapt to a novel environment is achieved through a balance of robustness and evolvability. Robustness is the invariance of phenotype in the face of perturbation and evolvability is the capacity to adapt in response to selection. Genetic robustness has been posited, depending on the underlying mechanism, to either decrease the efficacy of selection, or increase the possibility of future adaptation. However, the true effect of genetic robustness on evolvability in biological systems remains uncertain. Results Here we demonstrate that genetic robustness increases evolvability of thermotolerance in laboratory populations of the RNA virus φ6. We observed that populations founded by robust clones evolved greater resistance to heat shock, relative to populations founded by brittle (less-robust clones. Thus, we provide empirical evidence for the idea that robustness can promote evolvability in this environment, and further suggest that evolvability can arise indirectly via selection for robustness, rather than through direct selective action. Conclusion Our data imply that greater tolerance of mutational change is associated with virus adaptability in a new niche, a finding generally relevant to evolutionary biology, and informative for elucidating how viruses might evolve to emerge in new habitats and/or overcome novel therapies.

  19. Directed evolution of thermotolerant malic enzyme for improved malate production.

    Science.gov (United States)

    Morimoto, Yumi; Honda, Kohsuke; Ye, Xiaoting; Okano, Kenji; Ohtake, Hisao

    2014-02-01

    The directed evolution of the thermotolerant NADP(H)-dependent malic enzyme from Thermococcus kodakarensis was conducted to alter the cofactor preference of the enzyme from NADP(H) to NAD(H). The construction and screening of two generations of mutant libraries led to the isolation of a triple mutant that exhibited 6-fold higher kcat/Km with NAD(+) than the wild type. We serendipitously found that, in addition to the change in the cofactor preference, the reaction specificity of the mutant enzyme was altered. The reductive carboxylation of pyruvate to malate catalyzed by the wild type enzyme is accompanied by HCO(3)(-)-independent reduction of pyruvate and gives lactate as a byproduct. The reaction specificity of the triple mutant was significantly shifted to malate production and the mutant gave a less amount of the byproduct than the wild type. When the triple mutant enzyme was used as a catalyst for pyruvate carboxylation with NADH, the enzyme gave 1.2 times higher concentration of malate than the wild type with NADPH. Single-point mutation analysis revealed that the substitution of Arg221 with Gly is responsible for the shift in reaction specificity. This finding may shed light on the catalytic mechanisms of malic enzymes and other related CO2- and/or HCO(3)(-)-fixing enzymes. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Classical and Molecular Identification of Thermotolerant Campylobacters from Poultry Meat

    Directory of Open Access Journals (Sweden)

    Tina Zorman

    2002-01-01

    Full Text Available Poultry meat samples from Slovenian retail market were examined for the presence of thermotolerant campylobacters. The isolates were identified by phenotypic and genotypic methods. ISO 10272 recommendations were followed for phenotypic identification. Different PCR assays, targeting species specific DNA regions in C. jejuni and C. coli, were checked for their applicability in identification. High degree of tested samples was positive (27/33, with significant proportion of C. coli (32 % among identified strains. High percentage of C. jejuni strains (54 % were hippurate negative. Phenotypic identification was therefore found to be inconvenient because of the presence of the strains with atypical phenotype and possible misinterpretation of test results. Multiplex PCR, targeting hippuricase gene in C. jejuni and species specific region in C. coli, was found to be an efficient method that allowed fast, simple and accurate identification of C. jejuni and C. coli. FlaA PCR is a reliable method to identify the group C. jejuni/C. coli, but it does not differentiate between the two species. CdtB PCR is inconvenient because of many false negative and some false positive results.

  1. Oxytocin inhibits aggression in female Syrian hamsters.

    Science.gov (United States)

    Harmon, A C; Huhman, K L; Moore, T O; Albers, H E

    2002-12-01

    Dominant subordinate relationships are formed as the result of social conflict and are maintained at least in part by communication. At this time, little is known about the neural mechanisms that are responsible for coordinating the social behaviours (e.g. aggression) that occur in association with the formation and maintenance of these relationships. The purpose of the present study was to investigate the role of oxytocin (OXT) within the medial preoptic anterior hypothalamic continuum (MPOA-AH) in the control of aggression in female hamsters. OXT injected into the MPOA-AH immediately before testing significantly reduced the duration of aggression in a dose-dependent manner. Injection of an OXT antagonist 30 min before testing significantly increased the duration of aggression. In contrast, the duration of aggression was not altered when hamsters were tested either 30 min after injection of OXT or immediately following injection of an OXT-antagonist. These data support the hypothesis that OXT release within the MPOA-AH regulates social behaviours important in the formation and maintenance of dominant subordinate relationships in female hamsters.

  2. Enhanced lipid production in thermo-tolerant mutants of Chlorella pyrenoidosa NCIM 2738.

    Science.gov (United States)

    Sachdeva, Neha; Gupta, Ravi Prakash; Mathur, Anshu Shankar; Tuli, Deepak Kumar

    2016-12-01

    The present study aimed to develop thermo-tolerant mutants of Chlorella pyrenoidosa NCIM 2738 for high lipids production. For this, ethyl methane sulfonate was used, which generated two effective thermo-tolerant mutants, M18 and M24 of Chlorella pyrenoidosa NCIM 2738, capable of surviving at temperature up to 47°C and showing improved lipid and biomass yields. They showed 59.62% and 50.75% increase, respectively in lipid content compared to wild type at 30°C, which could not grow at temperature above 35°C. The novelty of this study lied in incorporation of PAM Flurometry with mutagenesis to generate thermo-tolerant mutants of C. pyrenoidosa and investigating the reasons for increased yields of mutants at cellular and photosynthetic levels with the aim to use them for commercial biodiesel production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Enhancing the Thermotolerance of Entomopathogenic Isaria fumosorosea SFP-198 Conidial Powder by Controlling the Moisture Content Using Drying and Adjuvants.

    Science.gov (United States)

    Kim, Jae Su; Lee, Se Jin; Lee, Hyang Burm

    2014-03-01

    Entomopathogenic fungi are promising pest-control agents but their industrial applicability is limited by their thermosusceptibility. With an aim to increase the thermotolerance of Isaria fumosorosea SFP-198, moisture absorbents were added to dried conidial powder, and the relationship between its water potential and thermotolerance was investigated. Mycotized rice grains were dried at 10℃, 20℃, 30℃, and 40℃ and the drying effect of each temperature for 24, 48, 96, and 140 hr was determined. Drying for 48 hr at 10℃ and 20℃ reduced the moisture content to < 5% without any significant loss of conidial thermotolerance, but drying at 30℃ and 40℃ reduced both moisture content and conidial thermotolerance. To maintain thermotolerance during storage, moisture absorbents, such as calcium chloride, silica gel, magnesium sulfate, white carbon, and sodium sulfate were individually added to previously dried-conidial powder at 10% (w/w). These mixtures was then stored at room temperature for 30 days and subjected to 50℃ for 2 hr. The white carbon mixture had the highest conidial thermotolerance, followed by silica gel, magnesium sulfate, and then the other absorbents. A significant correlation between the water potential and conidial thermotolerance was observed in all conidia-absorbent mixtures tested in this study (r = -0.945). Conidial thermotolerance in wet conditions was evaluated by adding moisturized white carbon (0~20% H2O) to conidia to mimic wet conditions. Notably, the conidia still maintained their thermotolerance under these conditions. Thus, it is evident that conidial thermotolerance can be maintained by drying mycotized rice grains at low temperatures and adding a moisture absorbent, such as white carbon.

  4. Development of a monoclonal antibody-based colony blot immunoassay for detection of thermotolerant Campylobacter species.

    Science.gov (United States)

    Huang, Hongsheng; Phipps-Todd, Beverley; McMahon, Tanis; Elmgren, Catherine L; Lutze-Wallace, Cheryl; Todd, Zoe A; Garcia, Manuel M

    2016-11-01

    Campylobacter species, particularly thermotolerant Campylobacter spp., such as C. jejuni, are major human foodborne pathogens. Culture methods have been routinely used for the detection of this organism in various types of samples. An alternative, simple and rapid confirmation test(s) without further tedious biochemical tests would be useful. Meanwhile, Campylobacter-like colonies can be difficult to identify on agar plates overgrown with competitive bacteria, which can lead to false-negative results. This study was to develop a simple colony blot immunoassay using a new monoclonal antibody (Mab) produced in the present study for rapid screening, confirmation and quantification of campylobacters on culture agar plates. The procedure developed in this study was able to specifically detect thermotolerant Campylobacter spp., but not other non-thermotolerant Campylobacter and non-Campylobacter reference strains tested. This assay could detect 10 5 cells in a single dot. This assay showed 100% correlation with the culture method for the blotted membranes from 21 either chicken meat or vegetable samples experimentally inoculated with thermotolerant campylobacters. Among 101 natural samples of chicken meat (n=44), chicken feces (n=20) and vegetables (n=37), this assay also showed positive for 23 chicken meat and 14 fecal samples that were positive for thermotolerant campylobacters by culture method, and identified four additional suspects that were culture negative. Membranes stored at 4°C for at least 4years could also be used for this assay. The assay developed in this study can be used in quantitative study for immediate or archival usage, and for diagnostic test to preliminarily confirm the presence of thermotolerant Campylobacter on agar plates. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  5. Thermotolerance of an inactivated rabies vaccine for dogs.

    Science.gov (United States)

    Lankester, Felix J; Wouters, Pieter A W M; Czupryna, Anna; Palmer, Guy H; Mzimbiri, Imam; Cleaveland, Sarah; Francis, Mike J; Sutton, David J; Sonnemans, Denny G P

    2016-11-04

    This study provides the first robust data that the antibody response of dogs vaccinated with Nobivac® Rabies vaccine stored for several months at high temperatures (up to 30°C) is not inferior to that of dogs vaccinated with vaccine stored under recommended cold-chain conditions (2-8°C). A controlled and randomized non-inferiority study was carried out comparing the four-week post vaccination serological responses of Tanzanian village dogs inoculated with vaccine which had been stored at elevated temperatures for different periods of time with those of dogs vaccinated with the same product stored according to label recommendations. Specifically, the neutralizing antibody response following the use of vaccine which had been stored for up to six months at 25°C or for three months at 30°C was not inferior to that following the use of cold-chain stored vaccine. These findings provide reassurance that the vaccine is likely to remain efficacious even if exposed to elevated temperatures for limited periods of time and, under these circumstances, it can safely be used and not necessarily destroyed or discarded. The availability of thermotolerant vaccines has been an important factor in the success of several disease control and elimination programs and could greatly increase the capacity of rabies vaccination campaigns to access hard to reach communities in Africa and Asia. We have not confirmed a 3-year duration of immunity for the high temperature stored vaccine, however because annual re-vaccination is usually practiced for dogs presented for vaccination during campaigns in Africa and Asia this should not be a cause for concern. These findings will provide confidence that, for rabies control and elimination programs using this vaccine in low-income settings, more flexible delivery models could be explored, including those that involve limited periods of transportation and storage at temperatures higher than that currently recommended. Copyright © 2016 The Authors

  6. [Histologic study on impeding leukoplakia carcinogenesis of golden hamster cheek pouch about Erigeron breviscapus (Vant) Hand-Mazz].

    Science.gov (United States)

    Zhou, C T; Zhong, W J; Hua, L; Hu, H F; Jin, Z G

    2000-06-01

    To observe the effect of Erigeron breviscapus (Vant) Hand Mazz (HEr) in impeding oral leukoplakia carcinogenesis, and to seek effective Chinese herb medicine that can impede precarcinoma of oral mucosas. 132 golden hamsters were randomly divided into model group (60 animals), HEr group (60 animals), and control group 12 animals. Salley's leukoplakia carcinogenesis model of golden hamster cheek pouch was used in this study. HEr was injected into the stomach to impede evolution of carcinogenesis. Pathological specimens were observed via naked eye and light microscope between model group and HEr group. Results were compared. Observation via naked-eye showed that leukoplakia rate of HEr group (18.2%) was lower than that of model group (27.3%). Observation via light microscope showed that carcinogenesis rate descended one fold and displasia rate descended 0.4 fold in HEr group. HEr has exact effect in impeding leukoplakia carcinogenesis.

  7. Production and purification of polyclonal anti-hamster ...

    African Journals Online (AJOL)

    user

    2011-01-17

    Jan 17, 2011 ... Purified antibody and its conjugation with HRP are used in research and diagnosis of hamster disease. Key words: Production, purification, hamster immunoglobulins. INTRODUCTION. Polyclonal antibodies represent a group or mixture of antibodies produced by different B-lymphocytes in res- ponse to the ...

  8. Radiation-induced anorexia in Syrian hamsters

    International Nuclear Information System (INIS)

    Kindt, A.; Sattler, E.L.; Schraub, A.

    1980-01-01

    The recovery of Syrian hamsters after split dose application (interval 11 days) was studied on the basis of the weight response and of food uptake. Two periods of weight loss and anorexia can be distinguished, an early one immediately after irradiation and a secondary one 6-10 days later. The secondary response is a function of the radiation dose and allows to distinguish survivors from non-survivors, since it is much more pronounced and longerlasting in the latter than in the former. The first response appears not to be influenced by a previous conditioning irradiation. (orig.) [de

  9. Pleurotus sajor-caju HSP100 complements a thermotolerance defect in hsp104 mutant Saccharomyces cerevisiae.

    Science.gov (United States)

    Lee, Jin-Ohk; Jeong, Mi-Jeong; Kwon, Tack-Ryun; Lee, Seung-Kon; Byun, Myung-Ok; Chung, Ill-Min; Park, Soo-Chul

    2006-06-01

    A putative Hsp100 gene was cloned from the fungus Pleurotus sajor-caju. mRNA expression studies demonstrated that this gene (designated PsHsp100) is highly induced by high temperature,induced less strongly by exposure to ethanol, and not induced by drought or salinity. Heat shock induction is detectable at 37 degrees C and reaches a maximum level at 42 degrees C. PsHsp100 mRNA levels sharply increased within 15 min of exposure to high temperature, and reached a maximum expression level at 2 h that was maintained for several hours. These results indicate that PsHsp100 could work at an early step in thermotolerance. To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomycetes cerivisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant yeast, allowing them being survive even at 50 degree C for 4 h. These results indicate that PsHSP100 protein is functional as an HSP100 in yeast and could play and important role in thermotolerance in P. sajor-caju.

  10. Isolation of thermotolerant campylobacters and C. hyointestinalis from rectal swabs of healthy pigs

    Directory of Open Access Journals (Sweden)

    Mrenoski Slavco

    2007-11-01

    Full Text Available Thermotolerant campylobacters are the most common bacterial etiological agents of human infectious gastroenteritis worldwide. The most frequent isolated species among them are Campylobacter jejuni and C. coli, and less frequent C. upsaliensis and C. lari. Also C. hyointestinalis, that not belong to the group of thermotolerant campylobacters, has been indicate as an agent of human infectious gastroenteritis. Natural reservoir of all named campylobacters is the intestinal tract of many mammals and birds, including domestic animals. In these animals, campylobacters are commonly present as commensals and their feces is considered as a prime source for environmental contamination. Unlike the human feces which is usually examined in the cases of diarrhea, thermotolerant campylobacters and C. hyointestinalis in the animal feces are generally present in a much lesser amount and the isolation very often could be unsuccessful. The aim of this study was to estimate the validity of applied procedure for isolation (and identification of thermotolerant campylobacters and C. hyointestinalis from pig rectal swabs, as a procedure for detection of healthy animal carriers.

  11. Perspectives on deciphering mechanisms underlying plant heat stress response and thermotolerance

    Directory of Open Access Journals (Sweden)

    Kamila Lucia Bokszczanin

    2013-08-01

    Full Text Available Global warming is a major threat for agriculture and food safety and in many cases the negative effects are already apparent. The current challenge of basic and applied plant science is to decipher the molecular mechanisms of heat stress response and thermotolerance in detail and use this information to identify genotypes that will withstand unfavorable environmental conditions. Nowadays X-omics approaches complement the findings of previous targeted studies and highlight the complexity of heat stress response mechanisms giving information for so far unrecognized genes, proteins and metabolites as potential key players of thermotolerance. Even more, roles of epigenetic mechanisms and the involvement of small RNAs in thermotolerance are currently emerging and thus open new directions of yet unexplored areas of plant heat stress response. In parallel it is emerging that although the whole plant is vulnerable to heat, specific organs are particularly sensitive to elevated temperatures. This has redirected research from the vegetative to generative tissues. The sexual reproduction phase is considered as the most sensitive to heat and specifically pollen exhibits the highest sensitivity and frequently an elevation of the temperature just a few degrees above the optimum during pollen development can have detrimental effects for crop production. Compared to our knowledge on heat stress response of vegetative tissues, the information on pollen is still scarce. Nowadays, several techniques for high-throughput X-omics approaches provide major tools to explore the principles of pollen heat stress response and thermotolerance mechanisms in specific genotypes. The collection of such information will provide an excellent support for improvement of breeding programs to facilitate the development of tolerant cultivars. The review aims at describing the current knowledge of thermotolerance mechanisms and the technical advances which will foster new insights into

  12. A modified anxious behavior test for hamsters.

    Science.gov (United States)

    Shannonhouse, John L; York, Daniel C; Morgan, Caurnel

    2014-01-15

    Latency to feed in a novel environment assesses anxious behavior in rodents, but it is unclear whether it distinguishes anxiety from consumption or appetite. The anxiety-related feeding/exploration conflict (AFEC) test was used here to assess anxious behavior in Syrian hamsters for which increased cheek-pouching of food, but not overconsumption of it, reflects appetitive drive, and orexigenic stimuli do not increase consumption. The setup of the test prevented cheek-pouching. Latency to approach test food provided an additional control for non-emotional effects of treatments. Feed and approach latencies in the test cage were normalized to those in the home cage to factor out non-emotional effects. Feed latency and the feed latency ratio (test cage/home cage) were reduced by acute treatment with benzodiazepine, diazepam, or beta-adrenergic receptor antagonist, propranolol, or chronic treatment with norepinephrine reuptake inhibitor, desipramine. Reductions of feed latency and the feed latency ratio were not associated with hyperphagia, and these behaviors were unaltered by acute treatment with opioid receptor antagonist, naltrexone. Latency to approach food in the test cage, with and without normalization, was unaltered by these treatments. Finally, overnight fasting elevated feed latency without hyperphagia, and this effect was attenuated by chronic desipramine treatment. These results suggest that the AFEC test assesses anxious, but not appetitive or consummatory, behavior, and that its sensitivity increases with food deprivation of hamsters. Copyright © 2013. Published by Elsevier B.V.

  13. Carcinoma de células escamosas em epitélio nasal de um hamster chinês: relato de caso

    OpenAIRE

    Rosolem, Mayara Caroline [UNESP; Romero, Débora Cristina; Rozza, Daniela Bernadete [UNESP; Souza, Natalia Cristina de [UNESP; Simões, Daniel Castendo

    2012-01-01

    The squamous cell carcinoma (SCC) is a neoplasm that affect pets, production animals and exotic animals, and it’s very common in tropical countries like Brazil, once it develops a sparsely pigmented, stratified squamous epithelium and on surfaces mucosa exposed to ultraviolet action. The SCC is quite infiltrative but rarely causes metastases. Its occurrence in the nasal epithelium is widely reported in cats. This case is a chinese hamster (Cricetulus griséus), female, young, who developed a n...

  14. Enhanced ethanol production from sugarcane juice by galactose adaptation of a newly isolated thermotolerant strain of Pichia kudriavzevii

    NARCIS (Netherlands)

    Dhaliwal, S.S.; Oberoi, H.S.; Sandhu, S.K.; Nanda, D.; Kumar, D.; Uppal, S.K.

    2011-01-01

    The thermotolerant yeast strain isolated from sugarcane juice through enrichment technique was identified as a strain of Pichiakudriavzevii (Issatchenkiaorientalis) through molecular characterization. The P. kudriavzevii cells adapted to galactose medium produced about 30% more ethanol from

  15. Kisspeptin and the seasonal control of reproduction in hamsters

    DEFF Research Database (Denmark)

    Simonneaux, Valérie; Ansel, Laura; Revel, Florent G

    2008-01-01

    -expressing neurons, which were recently shown to be implicated in the regulation of GnRH release. Hamsters are seasonal rodents which are sexually active in long photoperiod and quiescent in short photoperiod. The photoperiodic information is transmitted to the reproductive system by melatonin, a pineal...... in the arcuate nucleus of the Syrian hamster is lower in short photoperiod, when animals are sexually quiescent. Notably, intracerebroventricular infusion of Kiss1 gene product, kisspeptin, in hamsters kept in short photoperiod is able to override the inhibitory photoperiod and to reactivate sexual activity...

  16. The effect of slaughter operations on the contamination of chicken carcasses with thermotolerant Campylobacter

    DEFF Research Database (Denmark)

    Rosenquist, Hanne; Sommer, Helle Mølgaard; Nielsen, Niels L.

    2006-01-01

    To evaluate the effect of specific slaughter operations on the contamination of broiler carcasses with naturally occurring thermotolerant Campylobacter, experiments were carried out in two Danish commercial slaughter plants (Plant I and Plant 11). Six broiler flocks determined Campylobacter...... concentration of 0.5 log(10) cfu/g in average, whereas no significant changes were observed during this operation in Plant II. Air chilling (Plant 1) and water chilling (Plant 11), both including a carcass wash prior to the chilling operation, caused similar, but significant reductions of 0.83 and 0.97 log(10......) cfu/g, respectively. In packed frozen chickens (Plant II) an additional reduction of 1.38 log(10) cfu/g in average was obtained due to the freezing operation. In packed chilled chickens (Plant 1), however, the number of thermotolerant Campylobacter per gram remained at the same level as after air...

  17. Histaminergic regulation of seasonal metabolic rhythms in Siberian hamsters.

    Science.gov (United States)

    I'anson, Helen; Jethwa, Preeti H; Warner, Amy; Ebling, Francis J P

    2011-06-01

    We investigated whether histaminergic tone contributes to the seasonal catabolic state in Siberian hamsters by determining the effect of ablation of histaminergic neurons on food intake, metabolic rate and body weight. A ribosomal toxin (saporin) conjugated to orexin-B was infused into the ventral tuberomammillary region of the hypothalamus, since most histaminergic neurons express orexin receptors. This caused not only 75-80% loss of histaminergic neurons in the posterior hypothalamus, but also some loss of other orexin-receptor expressing cells e.g. MCH neurons. In the long-day anabolic state, lesions produced a transient post-surgical decrease in body weight, but the hamsters recovered and maintained constant body weight, whereas weight gradually increased in sham-lesioned hamsters. VO(2) in the dark phase was significantly higher in the lesioned hamsters compared to shams, and locomotor activity also tended to be higher. In a second study in short days, sham-treated hamsters showed the expected seasonal decrease in body weight, but weight remained constant in the lesioned hamsters, as in the long-day study. Lesioned hamsters consumed more during the early dark phase and less during the light phase due to an increase in the frequency of meals during the dark and decreased meal size during the light, and their cumulative food intake in their home cages was greater than in the control hamsters. In summary, ablation of orexin-responsive cells in the posterior hypothalamus blocks the short-day induced decline in body weight by preventing seasonal hypophagia, evidence consistent with the hypothesis that central histaminergic mechanisms contribute to long-term regulation of body weight. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Genetic manipulation of Bacillus methanolicus, a gram-positive, thermotolerant methylotroph.

    OpenAIRE

    Cue, D; Lam, H; Dillingham, R L; Hanson, R S; Flickinger, M C

    1997-01-01

    We report the fist genetic transformation system, shuttle vectors, and integrative vectors for the thermotolerant, methylotrophic bacterium Bacillus methanolicus. By using a polyethylene glycol-mediated transformation procedure, we have successfully transformed B. methanolicus with both integrative and multicopy plasmids. For plasmids with a single BmeTI recognition site, dam methylation of plasmid DNA (in vivo or in vitro) was found to enhance transformation efficiency from 7- to 11-fold. Tw...

  19. Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

    OpenAIRE

    Vereshchagina, Kseniya P.; Lubyaga, Yulia A.; Shatilina, Zhanna; Bedulina, Daria; Gurkov, Anton; Axenov-Gribanov, Denis V.; Baduev, Boris; Kondrateva, Elizaveta S.; Gubanov, Mikhail; Zadereev, Egor; Sokolova, Inna; Timofeyev, Maxim

    2016-01-01

    Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (c...

  20. Consortium inoculum of five thermo-tolerant phosphate solubilizing Actinomycetes for multipurpose biofertilizer preparation.

    Science.gov (United States)

    Nandimath, Arusha P; Karad, Dilip D; Gupta, Shantikumar G; Kharat, Arun S

    2017-10-01

    Alkaline pH of the soil facilitates the conversion of phosphate present in phosphate fertilizer applied in the field to insoluble phosphate which is not available to plants. Problem of soluble phosphate deficiency arises, primarily due to needless use of phosphate fertilizer. We sought to biofertilizer with the thermo-tolerant phosphate solubilizing actinomycetes consortium that could convert insoluble phosphate to soluble phosphate at wider temperature range. In the present investigation consortium of five thermo-tolerant phosphate solubilizing actinomycetes was applied for preparation of inoculum to produce multipurpose bio-fertilizer. Phosphates solubilizing thermo-tolerant 32 actinomycetes strains were processed for identification with the use of PIBWIN software and were screened for phosphate solubilizing activity. Amongst these five actinomycetes were selected on the basis of their ability to produce cellulase, chitinase, pectinase, protease, lipase, amylase and phosphate solubilizing enzymes. Ability to produce these enzymes at 28°C and 50°C were examined. Biofertilizer was prepared by using agricultural waste as a raw material. While preparation of bio-fertilizer the pH decreased from 7.5 to 4.3 and temperature increased up to 74°C maximum at the end of 4 th week and in subsequent week it started to decline gradually till it reached around 50°C, which was found to be stable up to eighth week. This thermo-tolerant actinomycetes consortium released soluble phosphate of up to 46.7 μg ml -1 . As the mesophilic organisms die out at high temperature of composting hence thormo-tolerant actinomycetes would be the better substitute for preparation of phosphate solubilizing bio-fertilizer with added potential to degrade complex macromolecules in composting.

  1. Site of resistance to Necator americanus in hamsters.

    Science.gov (United States)

    Rajasekariah, G R; Deb, B N; Dhage, K R; Bose, S

    1985-12-01

    Resistance to the development of human hookworm, Necator americanus was examined in 3- to 6-week-old young adult hamsters. Only 3% of N. americanus infective third stage larvae (NaL3) reached maturity in the intestines of young adults as opposed to as many as 60% in 2-day-old baby hamsters. This seemingly effective resistance prevailing in young adults was investigated in some detail. The skin, the first site of contact for the invading NaL3, was bypassed during the infection process. Completely in vitro exsheathed NaL3 (ExNaL3) were used, and young adult hamsters were infected parenterally, by-passing the skin. Even after exsheathing the larvae artificially before infection and by-passing the skin, no improvement was seen in the development of N. americanus in the intestines of young adults. Higher infection doses also did not increase the worm burden. Some of the factors limiting the development of parasites in young adults were examined. N. americanus were monitored in lungs and intestines during various intervals after infection. Similar parasite burdens were apparent in lungs of baby as well as young adult hamsters. In the intestines, a significantly lower burden of N. americanus was seen during various intervals in young adults compared to the baby hamsters. Moreover, N. americanus were expelled soon after reaching the intestine. This comparative monitoring revealed the intestine as the seat of resistance against the establishment of N. americanus in young adult hamsters.

  2. Comparison of thermotolerant coliforms and Escherichia coli densities in freshwater bodies.

    Science.gov (United States)

    Hachich, Elayse M; Di Bari, Marisa; Christ, Ana Paula G; Lamparelli, Cláudia C; Ramos, Solange S; Sato, Maria Inês Z

    2012-04-01

    Fecal bacterial indicator analyses have been widely used for monitoring the water quality. This study was designed to determine the ratio between the density of Escherichia coli and other Thermotolerant Coliforms (TtC) bacteria from freshwater samples collected for a two-year period of monitoring. TtC were enumerated by membrane filtration on mFC agar. E. coli enumeration was done by two methods: TtC colonies identified in mFC were inoculated in EC-MUG or water samples were filtered and inoculated in modified mTEC agar media, and both methods were compared for quantitative recovery of E. coli. The results pointed out a mean percentage of E. coli among other thermotolerant coliforms (E. coli/TtC ratio) of 84.3% in mFC media. Taking these results into account, a mandatory standard of 1000 thermotolerant coliforms would correspond to 800 E. coli and the adoption of these E. coli based standards will represent a major improvement for the monitoring of freshwater quality.

  3. Trampling Impacts on Thermotolerant Vegetation of Geothermal Areas in New Zealand

    Science.gov (United States)

    Burns, Bruce R.; Ward, Jonet; Downs, Theresa M.

    2013-12-01

    Geothermal features such as geysers, mud pools, sinter terraces, fumaroles, hot springs, and steaming ground are natural attractions often visited by tourists. Visitation rates for such areas in the Taupo Volcanic Zone of New Zealand are in the order of hundreds of thousands annually. These areas are also habitat for rare and specialized plant and microbial communities that live in the steam-heated soils of unusual chemical composition. We evaluated historical and current trampling impacts of tourists on the thermotolerant vegetation of the Waimangu and Waiotapu geothermal areas near Rotorua, and compared the results to experimental trampling at a third site (Taheke) not used by tourists. Historical tourism has removed vegetation and soil from around key features, and remaining subsoil is compacted into an impervious pavement on which vegetation recolonization is unlikely in the short term. Social tracks made by tourists were present at both tourist sites often leading them onto hotter soils than constructed tracks. Vegetation height and cover were lower on and adjacent to social tracks than further from them. Thermotolerant vegetation showed extremely low resistance to experimental trampling. This confirms and extends previous research that also shows that thallophytes and woody shrubs, life forms that dominate in thermotolerant vegetation, are vulnerable to trampling damage. Preservation of these vulnerable ecosystems must ensure that tourist traffic is confined to existing tracks or boardwalks, and active restoration of impacted sites may be warranted.

  4. Trampling impacts on thermotolerant vegetation of geothermal areas in New Zealand.

    Science.gov (United States)

    Burns, Bruce R; Ward, Jonet; Downs, Theresa M

    2013-12-01

    Geothermal features such as geysers, mud pools, sinter terraces, fumaroles, hot springs, and steaming ground are natural attractions often visited by tourists. Visitation rates for such areas in the Taupo Volcanic Zone of New Zealand are in the order of hundreds of thousands annually. These areas are also habitat for rare and specialized plant and microbial communities that live in the steam-heated soils of unusual chemical composition. We evaluated historical and current trampling impacts of tourists on the thermotolerant vegetation of the Waimangu and Waiotapu geothermal areas near Rotorua, and compared the results to experimental trampling at a third site (Taheke) not used by tourists. Historical tourism has removed vegetation and soil from around key features, and remaining subsoil is compacted into an impervious pavement on which vegetation recolonization is unlikely in the short term. Social tracks made by tourists were present at both tourist sites often leading them onto hotter soils than constructed tracks. Vegetation height and cover were lower on and adjacent to social tracks than further from them. Thermotolerant vegetation showed extremely low resistance to experimental trampling. This confirms and extends previous research that also shows that thallophytes and woody shrubs, life forms that dominate in thermotolerant vegetation, are vulnerable to trampling damage. Preservation of these vulnerable ecosystems must ensure that tourist traffic is confined to existing tracks or boardwalks, and active restoration of impacted sites may be warranted.

  5. Thermotolerant Coliforms Are Not a Good Surrogate for Campylobacter spp. in Environmental Water ▿

    Science.gov (United States)

    St-Pierre, Karen; Lévesque, Simon; Frost, Eric; Carrier, Nathalie; Arbeit, Robert D.; Michaud, Sophie

    2009-01-01

    This study aimed to assess the importance of quantitatively detecting Campylobacter spp. in environmental surface water. The prevalence and the quantity of Campylobacter spp., thermotolerant coliforms, and Escherichia coli in 2,471 samples collected weekly, over a 2-year period, from 13 rivers and 12 streams in the Eastern Townships, Québec, Canada, were determined. Overall, 1,071 (43%), 1,481 (60%), and 1,463 (59%) samples were positive for Campylobacter spp., thermotolerant coliforms, and E. coli, respectively. There were weak correlations between the weekly distributions of Campylobacter spp. and thermotolerant coliforms (Spearman's ρ coefficient = 0.27; P = 0.008) and between the quantitative levels of the two classes of organisms (Kendall tau-b correlation coefficient = 0.233; P coliforms. These findings suggest that microbial monitoring of raw water by using only fecal indicator organisms is not sufficient for assessing the occurrence or the load of thermophilic Campylobacter spp. Insights into the role of environmental water as sources for sporadic Campylobacter infection will require genus-specific monitoring techniques. PMID:19734335

  6. Thermotolerant coliforms are not a good surrogate for Campylobacter spp. in environmental water.

    Science.gov (United States)

    St-Pierre, Karen; Lévesque, Simon; Frost, Eric; Carrier, Nathalie; Arbeit, Robert D; Michaud, Sophie

    2009-11-01

    This study aimed to assess the importance of quantitatively detecting Campylobacter spp. in environmental surface water. The prevalence and the quantity of Campylobacter spp., thermotolerant coliforms, and Escherichia coli in 2,471 samples collected weekly, over a 2-year period, from 13 rivers and 12 streams in the Eastern Townships, Québec, Canada, were determined. Overall, 1,071 (43%), 1,481 (60%), and 1,463 (59%) samples were positive for Campylobacter spp., thermotolerant coliforms, and E. coli, respectively. There were weak correlations between the weekly distributions of Campylobacter spp. and thermotolerant coliforms (Spearman's rho coefficient = 0.27; P = 0.008) and between the quantitative levels of the two classes of organisms (Kendall tau-b correlation coefficient = 0.233; P coliforms. These findings suggest that microbial monitoring of raw water by using only fecal indicator organisms is not sufficient for assessing the occurrence or the load of thermophilic Campylobacter spp. Insights into the role of environmental water as sources for sporadic Campylobacter infection will require genus-specific monitoring techniques.

  7. Screening of thermotolerant and thermophilic fungi aiming β-xylosidase and arabinanase production

    Science.gov (United States)

    Benassi, Vivian Machado; de Lucas, Rosymar Coutinho; Jorge, João Atílio; Polizeli, Maria de Lourdes Teixeira de Moraes

    2014-01-01

    Plant cell wall is mainly composed by cellulose, hemicellulose and lignin. The heterogeneous structure and composition of the hemicellulose are key impediments to its depolymerization and subsequent use in fermentation processes. Thus, this study aimed to perform a screening of thermophilic and thermotolerant filamentous fungi collected from different regions of the São Paulo state, and analyze the production of β-xylosidase and arabinanase at different temperatures. These enzymes are important to cell wall degradation and synthesis of end products as xylose and arabinose, respectively, which are significant sugars to fermentation and ethanol production. A total of 12 fungal species were analyzed and 9 of them grew at 45 °C, suggesting a thermophilic or thermotolerant character. Additionally Aspergillus thermomutatus anamorph of Neosartorya and A. parasiticus grew at 50 °C. Aspergillus niger and Aspergillus thermomutatus were the filamentous fungi with the most expressive production of β-xylosidase and arabinanase, respectively. In general for most of the tested microorganisms, β-xylosidase and arabinanase activities from mycelial extract (intracellular form) were higher in cultures grown at high temperatures (35–40 °C), while the correspondent extracellular activities were favorably secreted from cultures at 30 °C. This study contributes to catalogue isolated fungi of the state of São Paulo, and these findings could be promising sources for thermophilic and thermotolerant microorganisms, which are industrially important due to their enzymes. PMID:25763055

  8. Active Hexose Correlated Compound Extends the Lifespan and Increases the Thermotolerance of Nematodes

    Directory of Open Access Journals (Sweden)

    Tetsuya Okuyama

    2013-06-01

    Full Text Available ABSTRACTBackground: Active hexose correlated compound (AHCC is the extract from cultured mycelia of Lentinula edodes, a species of Basidiomycetes mushroom. AHCC contains various polysaccharides, including partially acylated -1,4-glucan, which is one of its major constituents. The application of AHCC has been markedly increased in complementary and alternative medicine as a functional food because AHCC improved the prognosis of postoperative hepatocellular carcinoma patients. AHCC has anti-inflammatory and antioxidant effects, such as the suppression of nitric oxide production in hepatocytes. AHCC might affect resistance to environmental stress, which is assumed to play a pivotal role in the longevity of many organisms.Objective: To investigate the effect of AHCC on longevity, we measured the lifespan of the nematode Caenorhabditis elegans, a model animal that is widely used to assess longevity. We also examined the effect of AHCC on resistance to heat stress, i.e., thermotolerance.Methods: The lifespan of C. elegans animals grown on media in the absence or presence of AHCC at 20°C was evaluated. Thermotolerance assays were performed at 35°C, the restrictive temperature of the animals. The effects of AHCC on lifespan and thermotolerance were analyzed with longevity mutants. Expression levels of stress-related genes, including heat shock genes, were measured by strand-specific reverse transcription-polymerase chain reaction after heat shock.Results: Wild-type C. elegans animals exhibited a longer mean lifespan by up to 10% in the presence of AHCC in the growth media than animals in the absence of AHCC. Furthermore, AHCC markedly increased thermotolerance at 35°C. Epistasis analyses showed that lifespan extension by AHCC at least partly required two longevity-promoting transcription factors: DAF-16 (C. elegans homolog of FOXO and HSF-1 (C. elegans homolog of heat shock transcription factor 1. After heat shock, AHCC activated the transcription

  9. Thermotolerance and responses to short duration heat stress in tropical and temperate species

    Science.gov (United States)

    Marias, D.; Meinzer, F. C.; Still, C. J.

    2017-12-01

    Temperature and heat waves are predicted to increase throughout the 21st century in both tropical and temperate regions. Tropical species are vulnerable to heat stress because of the higher radiation load and the narrower distribution of temperatures typically experienced compared to extratropical species. Germinant seedlings are also vulnerable to heat stress because they inhabit the boundary layer close to the soil surface where intense heating occurs. We quantified the effect of leaf age and heat stress duration (45 min, 90 min) on leaf thermotolerance and whole plant physiological responses to heat stress in Coffea arabica (COAR) saplings. We also evaluated leaf thermotolerance and whole plant responses to heat stress of seedlings in two populations each of Pinus ponderosa (PIPO) and Pseudotsuga menziesii (PSME) from contrasting climates. Thermotolerance of detached leaves/needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. After exposure of whole plants to a simulated heat wave in a growth chamber, we monitored FV/FM, photosynthesis (A), stomatal conductance (gs), non-structural carbohydrates (NSCs), and carbon isotope ratios (δ13C). In COAR, thermotolerance and rate of recovery increased with leaf age. Following heat treatment, reductions in A and gs led to reduced intrinsic water use efficiency (iWUE) and increased leaf temperatures. NSC results suggested that starch was converted to sugars for recovery from heat stress and phloem transport was inhibited. Plants failed to flower in both heat stress duration treatments. In PIPO and PSME, heat treatment induced significant reductions in FV/FM and A. NSC results suggested that starch was converted to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites had greater δ13C values than those from wetter sites, consistent with higher iWUE of populations from drier climates. Thermotolerance and heat stress responses appeared to be

  10. Superior thermotolerance of Saccharomyces cerevisiae for efficient bioethanol fermentation can be achieved by overexpression of RSP5 ubiquitin ligase.

    Science.gov (United States)

    Shahsavarani, Hosein; Sugiyama, Minetaka; Kaneko, Yoshinobu; Chuenchit, Boonchird; Harashima, Satoshi

    2012-01-01

    The simultaneous saccharification and fermentation process requires thermo-tolerant yeast to facilitate the enzymatic hydrolysis of cellulose. In this paper, we describe a Htg+ strain that exhibits confluent growth at high temperature (41 °C) and resistance to heat shock, ethanol, osmotic, oxidative and DNA damage stresses. HTG6, one of the six genes responsible for the thermotolerant phenotype was identified to be the gene RSP5 encoding a ubiquitin ligase. The RSP5 allele of the Htg+ strain, designated RSP5-C, possessed five, one and two base changes in the promoter, open reading frame and terminator region, respectively. The base changes in the promoter region of the RSP5-C allele were found to be responsible for the thermotolerant phenotype by strongly increasing transcription of the RSP5 gene and consequently causing a rise in the ubiquitination of cell proteins. Overexpression of the RSP5-BY allele present in the htg6 host strain (Htg-) conferred thermotolerance at 41°C, to this strain as in the case of RSP5-C allele. We also discovered that an Htg+ strain overexpressing the RSP5-C allele exhibits a more robust Htg+ phenotype against higher temperature (43 °C). The data presented here also suggest that overexpression of RSP5 could be applied to raise the upper limit of thermotolerance in S. cerevisiae strain used for industrial bioethanol production. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Social context modulates food hoarding in Syrian hamsters

    Directory of Open Access Journals (Sweden)

    Bibiana Montoya

    2016-09-01

    Full Text Available The effect of the presence of a con-specific in the temporal organization of food hoarding was studied in two varieties of Syrian hamster (Mesocricetus auratus: golden and long-haired. Four male hamsters of each variety were used. Their foraging behavior was observed during four individual and four shared trials in which animals were not competing for the same food source or territory. During individual trials, long-haired hamsters consumed food items directly from the food source, transporting and hoarding only remaining pieces. During shared trials, the long-haired variety hoarded food items before consumption, and increased the duration of hoarding trips, food handling in the storage, and cache size. Golden hamsters maintained the same temporal organization of hoarding behavior (i.e., hoarding food items before consumption throughout both individual and shared trials. However, the golden variety increased handling time at the food source and decreased the duration of hoarding trips, the latency of hoarding and storing size throughout the shared trials. In Syrian hamsters, the presence of a con-specific may signal high probability of food source depletion suggesting that social pressures over food availability might facilitate hoarding behavior. Further studies are required to evaluate cost-benefit balance of food hoarding and the role of cache pilferage in this species.

  12. Hamster and Murine Models of Severe Destructive Lyme Arthritis

    Directory of Open Access Journals (Sweden)

    Erik Munson

    2012-01-01

    Full Text Available Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ- deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology.

  13. Hamster and Murine Models of Severe Destructive Lyme Arthritis

    Science.gov (United States)

    Munson, Erik; Nardelli, Dean T.; Du Chateau, Brian K.; Callister, Steven M.; Schell, Ronald F.

    2012-01-01

    Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology. PMID:22461836

  14. Genitourinary changes in hamsters infected and reinfected with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Cabrine-Santos Marlene

    2003-01-01

    Full Text Available Authors describe genitourinary changes in male hamsters infected and reinfected with Trypanosoma cruzi. Changes in genital organs have been described in human and in experimental chagasic infection. Genital dysfunctions in chronic chagasic patients affect ejaculation, libido and sexual potency, and testis biopsies may show arrested maturation of germ cells, oligozoospermia and azoospermia. Sixty-five male hamsters were inoculated and reinoculated with 2x10³ trypomastigotes of T. cruzi VIC strain, and 22 non-infected animals constituted the control group. Animals were necropsied and fragments from testis, epididymis, seminal vesicle and bladder were collected and stained with hematoxylin-eosin. Peroxidase anti-peroxidase procedure was utilized to detect tissue parasitism. T. cruzi nests were found in testis, epididymis and seminal vesicle of these hamsters. Such parasitism plays a role in the origin of genital lesions observed in humans and laboratory animals during chronic chagasic infection.

  15. Arnica Tincture Cures Cutaneous Leishmaniasis in Golden Hamsters

    Directory of Open Access Journals (Sweden)

    Sara M. Robledo

    2018-01-01

    Full Text Available In search for potential therapeutic alternatives to existing treatments for cutaneous Leishmaniasis, we have investigated the effect of Arnica tincture Ph. Eur. (a 70% hydroethanolic tincture prepared from flowerheads of Arnica montana L. on the lesions caused by infection with Leishmania braziliensis in a model with golden hamsters. The animals were treated topically with a daily single dose of the preparation for 28 days. Subsequently, the healing process was monitored by recording the lesion size in intervals of 15 days up to day 90. As a result, Arnica tincture fully cured three out of five hamsters while one animal showed an improvement and another one suffered from a relapse. This result was slightly better than that obtained with the positive control, meglumine antimonate, which cured two of five hamsters while the other three showed a relapse after 90 days. This result encourages us to further investigate the potential of Arnica tincture in the treatment of cutaneous Leishmaniasis.

  16. Hamster thecal cells express muscle characteristics

    International Nuclear Information System (INIS)

    Self, D.A.; Schroeder, P.C.; Gown, A.M.

    1988-01-01

    Contraction of the follicular wall about the time of ovulation appears to be a coordinated event; however, the cells that mediate it remain poorly studied. We examined the theca externa cells in the wall of hamster follicles for the presence of a functional actomyosin system, both in developing follicles and in culture. We used a monoclonal antibody (HHF35) that recognizes the alpha and gamma isoelectric variants of actin normally found in muscle, but not the beta variant associated with non-muscle sources, to evaluate large preovulatory follicles for actin content and composition. Antibody staining of sectioned ovaries showed intense circumferential reactivity in the outermost wall of developing follicles. Immunoblots from two-dimensional gels of theca externa lysates demonstrated the presence of the two muscle-specific isozymes of actin. Immunofluorescence of cultured follicular cells pulse-labeled with [3H] thymidine (for autoradiographic detection of DNA replication) revealed the presence, in many dividing cells, of actin filaments aligned primarily along the longitudinal axis of the cells. In cultures exposed to the calcium ionophore A23187 (10(-4) M) for varying periods (5 min to 1 h), contraction of many individual muscle-actin-positive cells was observed. Immunofluorescence of these cells, fixed immediately after ionophore-induced contraction, revealed compaction of the actin filaments. Our findings demonstrate that the cells of the theca externa contain muscle actins from an early stage and that these cells are capable of contraction even while proliferating in subconfluent cultures. They suggest that follicular growth may include a naturally occurring developmental sequence in which a contractile cell type proliferates in the differentiated state

  17. Preliminary physiological characteristics of thermotolerant Saccharomyces cerevisiae clinical isolates identified by molecular biology techniques.

    Science.gov (United States)

    Siedlarz, P; Sroka, M; Dyląg, M; Nawrot, U; Gonchar, M; Kus-Liśkiewicz, M

    2016-03-01

    The aim of the study was a molecular identification and physiological characteristic of the five Saccharomyces cerevisiae strains isolated from patients. The tested isolates were compared with control strains (which are of laboratory or commercial origin). The relation of the isolates to baker's yeast S. cerevisiae was studied using species-specific primers in PCR analysis of the ITS-26S region of DNA. Five isolates were genetically identified as the yeast belonging to the genus S. cerevisiae. The effects of temperature and carbon sources on the growth of the yeast strains were analysed. A quantitative characterization of growth kinetics approve that some tested isolates are thermotolerant and are able to grow at range 37-39°C. Among them, one representative is characterized by the highest specific growth rate (0·637 h(-1) ). In conclusions, some strains are defined as potential candidates to use in the biotechnology due to a higher growth rate at elevated temperatures. Screening for further evaluation of biotechnological significance of the tested isolates will be done (e.g. ethanol and trehalose production at higher temperatures). The physiological characterization and confirmation of species identification by molecular methods for yeasts important in the context of biotechnology industry were demonstrated. Thermotolerant microbial strains are required in various industrial applications, for improving productivity and for decreasing the risk of undesirable contaminations when higher temperatures are used. It is important to search for such strains in extreme environments or exotic niches. In this paper, new thermotolerant strains were identified belonging to the Saccharomyces cerevisiae, but differed from typical bakers' yeast, essentially by their growth rate at higher temperature. The described yeast strains are promising for using in biotechnological industry, especially, for production of ethanol and other products at higher temperatures. © 2015 The

  18. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion.

    Science.gov (United States)

    Techaparin, Atiya; Thanonkeo, Pornthap; Klanrit, Preekamol

    The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45°C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40°C and 43°C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37°C with an ethanol concentration of 72.69g/L, a productivity of 1.59g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40°C were achieved using the Box-Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32g/L, with a productivity of 2.48g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  19. Bioprospecting thermotolerant ethanologenic yeasts for simultaneous saccharification and fermentation from diverse environments.

    Science.gov (United States)

    Choudhary, Jairam; Singh, Surender; Nain, Lata

    2017-03-01

    Lignocellulosic biomass, a promising renewable energy source, can be used for the production of second generation bioethanol. Simultaneous saccharification and fermentation (SSF), the process which alleviates the problem of separate hydrolysis and fermentation (SHF), requires thermotolerant ethanologenic yeast for bioethanol production. Therefore, ten yeast strains isolated from diverse sources, belonging to various genera like Saccharomyces, Candida, Pichia and Wickerhamomyces were evaluated for their thermotolerance, sugar utilization pattern, inhibitor tolerance and ethanol production potential with glucose, xylose and alkali pretreated paddy straw. All the tested strains were found to be thermotolerant, capable of significant growth at 40°C. Candida tropicalis Y6 was capable of utilizing a wide range of sugars as compared with other yeast isolates. Strains of Candida showed better inhibitor tolerance as compared to Saccharomyces and Pichia strains and exhibited only 5.1-18.8% and 4.7-7.9% reduction in growth with furfural and 5-hydroxymethyl furfural, respectively. Saccharomyces cerevisiae JRC6, isolated from distillery waste, produced ethanol with 88.3% and 89.1% theoretical efficiency at 40°C and 42°C, respectively, from glucose. This strain also produced significantly higher amount of ethanol (3.8 g/L) with better fermentation efficiency (87.9%) from alkali pretreated paddy straw at 40°C, as compared with the other yeast strains. Therefore, S. cerevisiae JRC6, based on its ability to ferment sugars at a higher temperature, can be a promising candidate for production of ethanol from lignocellulosic biomass via SSF process. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Atiya Techaparin

    Full Text Available Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v, respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ at 40 °C were achieved using the Box-Behnken experimental design (BBD. The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

  1. Production of pullulan by a thermotolerant Aureobasidium pullulans strain in non-stirred fed batch fermentation process

    OpenAIRE

    Singh, Ranjan; Gaur, Rajeeva; Tiwari, Soni; Gaur, Manogya Kumar

    2012-01-01

    Total 95 isolates of Aureobasidium pullulans were isolated from different flowers and leaves samples, out of which 11 thermotolerant strains produced pullulan. One thermotolerant non-melanin pullulan producing strain, designated as RG-5, produced highest pullulan (37.1±1.0 g/l) at 42ºC, pH 5.5 in 48h of incubation with 3% sucrose and 0.5% ammonium sulphate in a non-stirred fed batch fermentor of 6 liters capacity. The two liters of initial volume of fermentation medium was further fed with th...

  2. Thermotolerant yeasts selected by adaptive evolution express heat stress response at 30ºC

    DEFF Research Database (Denmark)

    Caspeta, Luis; Chen, Yun; Nielsen, Jens

    2016-01-01

    to grow at increased temperature, activated a constitutive heat stress response when grown at the optimal ancestral temperature, and that this is associated with a reduced growth rate. This preventive response was perfected by additional transcriptional changes activated when the cultivation temperature...... temperatures, but this also causes a trade-off in the growth rate at the optimal ancestral temperature.......Exposure to long-term environmental changes across >100s of generations results in adapted phenotypes, but little is known about how metabolic and transcriptional responses are optimized in these processes. Here, we show that thermotolerant yeast strains selected by adaptive laboratory evolution...

  3. Sea urchin development in a global change hotspot, potential for southerly migration of thermotolerant propagules

    Science.gov (United States)

    Byrne, M.; Selvakumaraswamy, P.; Ho, M. A.; Woolsey, E.; Nguyen, H. D.

    2011-03-01

    The distribution of the sea urchin Heliocidaris erythrogramma coincides with the southeast Australia global change hot spot where marine ecosystems are warming significantly due to changes in ocean circulation. To address questions on future vulnerabilities, the thermotolerance of the planktonic life phase of H. erythrogramma was investigated in the climate and regionally relevant setting of projected near-future (2100) ocean warming. Experimental treatments ranged from 18 to 26 °C, with 26 °C representing +3-4 °C above recent ambient sea-surface temperatures. Developmental success across all stages (gastrula, 24 h; larva, 72 h; juvenile, 120 h) decreased with increasing temperature. Development was tolerant to a +1-2 °C increase above ambient, but significant deleterious effects were evident at +3-4 °C. However, larvae that developed through the early bottleneck of normal development at 26 °C metamorphosed successfully. The inverse relationship between temperature and planktonic larval duration (PLD) was seen in a 25% decrease in the PLD of H. erythrogramma at 24 and 26 oC. Ocean warming may be advantageous to a subset of larvae through early settlement and reduction of the vulnerable planktonic period. This positive effect of temperature may help buffer the negative effects of ocean warming. In parallel studies with progeny derived from northern (Coffs Harbour) and southern (Sydney) H. erythrogramma, northern embryos had significantly higher thermotolerance. This provides the possibility that H. erythrogramma populations might keep up with a warming world through poleward migration of thermotolerant propagules, facilitated by the strong southward flow of the East Australian Current. It is uncertain whether H. erythrogramma populations at the northern range of this species, with no source of immigrants, will have the capacity to persist in a warm ocean. Due to its extensive latitudinal distribution, its potential developmental thermotolerance and

  4. Thermo-tolerant phosphate-solubilizing microbes for multi-functional biofertilizer preparation.

    Science.gov (United States)

    Chang, Cheng-Hsiung; Yang, Shang-Shyng

    2009-02-01

    In order to prepare the multi-functional biofertilizer, thermo-tolerant phosphate-solubilizing microbes including bacteria, actinomycetes, and fungi were isolated from different compost plants and biofertilizers. Except Streptomycesthermophilus J57 which lacked pectinase, all isolates possessed amylase, CMCase, chitinase, pectinase, protease, lipase, and nitrogenase activities. All isolates could solubilize calcium phosphate and Israel rock phosphate; various isolates could solubilize aluminum phosphate, iron phosphate, and hydroxyapatite. During composting, biofertilizers inoculated with the tested microbes had a significantly higher temperature, ash content, pH, total nitrogen, soluble phosphorus content, and germination rate than non-inoculated biofertilizer; total organic carbon and carbon-to-nitrogen ratio showed the opposite pattern. Adding these microbes can shorten the period of maturity, improve the quality, increase the soluble phosphorus content, and enhance the populations of phosphate-solubilizing and proteolytic microbes in biofertilizers. Therefore, inoculating thermo-tolerant phosphate-solubilizing microbes into agricultural and animal wastes represents a practical strategy for preparing multi-functional biofertilizer.

  5. The growth profile, thermotolerance and biofilm formation of Enterobacter sakazakii grown in infant formula milk.

    Science.gov (United States)

    Iversen, C; Lane, M; Forsythe, S J

    2004-01-01

    To study the growth, thermotolerance and biofilm formation of the emergent pathogen Enterobacter sakazakii in infant formula milk (IFM). The temperature range, death kinetics and biofilm formation of E. sakazakii were determined using impedance microbiology and conventional methods. In IFM the organism grew as low as 6 degrees C and optimally at 37-43 degrees C. In faecal coliform tests, 23% of strains (n = 70) produced gas from lauryl sulphate broth (LSB) at 44 degrees C after 48 h incubation. Three strains failed to grow in LSB at any of the temperatures. The D-value of cells suspended in IFM was determined between 54 and 62 degrees C. The resultant z-value was 5.7 degrees C. The organism was able to adhere and grow on latex, polycarbonate, silicon and to a lesser extent stainless steel. Enterobacter sakazakii was able to grow at refrigeration temperatures and on infant-feeding equipment. The thermotolerance of the organism was similar to other Enterobacteriaceae and should be killed during standard pasteurization treatment. Enterobacter sakazakii has been associated with infant meningitis through consumption of contaminated IFM. Enterobacter sakazakii is able to grow in IFM during storage at refrigeration temperatures and attach to infant-feeding equipment, which may become reservoirs of infection.

  6. Elucidation of thermotolerance diversity in cotton (Gossypium hirsutum L.) using physio-molecular approaches.

    Science.gov (United States)

    Rana, R M; Khan, S H; Ali, Z; Khan, A I; Khan, I A

    2011-06-14

    Cotton (Gossypium hirsutum) is an important cash crop, but high temperature during its growing season is one of the major factors that limit its productivity. This problem compels plant breeders to breed for heat tolerance, which can help to overcome this challenge. It is very important to make a comprehensive screening of heat-tolerant genotypes so that only the best are chosen. Here we report the combined use of several techniques that can help breeders to screen their germplasm. Twelve cultivated cotton genotypes were evaluated for thermotolerance, using assays that included electrolyte leakage, chlorophyll accumulation and protein profiling, as well as RAPDs to assess genetic diversity. Two genotypes (B-557 and NIAB-78) showed tolerant behavior in three thermotolerance assays. RAPD analysis results showed maximum similarity in a range of 86.7-66.7% between the genotypes MNH-554 and CIM-443. We conclude that combined use should be made of relative electrolyte leakage, chlorophyll stability and differential display with SDS-PAGE to aid in screening for stress tolerance. RAPD-based diversity analysis will further help to improve the efficiency of breeding programs.

  7. Changes in Salicylic Acid and Antioxidants during Induced Thermotolerance in Mustard Seedlings

    Science.gov (United States)

    Dat, James F.; Foyer, Christine H.; Scott, Ian M.

    1998-01-01

    Heat-acclimation or salicylic acid (SA) treatments were previously shown to induce thermotolerance in mustard (Sinapis alba L.) seedlings from 1.5 to 4 h after treatment. In the present study we investigated changes in endogenous SA and antioxidants in relation to induced thermotolerance. Thirty minutes into a 1-h heat-acclimation treatment glucosylated SA had increased 5.5-fold and then declined during the next 6 h. Increases in free SA were smaller (2-fold) but significant. Changes in antioxidants showed the following similarities after either heat-acclimation or SA treatment. The reduced-to-oxidized ascorbate ratio was 5-fold lower than the controls 1 h after treatment but recovered by 2 h. The glutathione pool became slightly more oxidized from 2 h after treatment. Glutathione reductase activity was more than 50% higher during the first 2 h. Activities of dehydroascorbate reductase and monodehydroascorbate reductase decreased by at least 25% during the first 2 h but were 20% to 60% higher than the control levels after 3 to 6 h. One hour after heat acclimation ascorbate peroxidase activity was increased by 30%. Young leaves appeared to be better protected by antioxidant enzymes following heat acclimation than the cotyledons or stem. Changes in endogenous SA and antioxidants may be involved in heat acclimation. PMID:9847121

  8. Salinity modulates thermotolerance, energy metabolism and stress response in amphipodsGammarus lacustris.

    Science.gov (United States)

    Vereshchagina, Kseniya P; Lubyaga, Yulia A; Shatilina, Zhanna; Bedulina, Daria; Gurkov, Anton; Axenov-Gribanov, Denis V; Baduev, Boris; Kondrateva, Elizaveta S; Gubanov, Mikhail; Zadereev, Egor; Sokolova, Inna; Timofeyev, Maxim

    2016-01-01

    Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress.

  9. Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

    Directory of Open Access Journals (Sweden)

    Kseniya P. Vereshchagina

    2016-11-01

    Full Text Available Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate. Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress.

  10. Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

    Science.gov (United States)

    Vereshchagina, Kseniya P.; Lubyaga, Yulia A.; Shatilina, Zhanna; Bedulina, Daria; Gurkov, Anton; Axenov-Gribanov, Denis V.; Baduev, Boris; Kondrateva, Elizaveta S.; Gubanov, Mikhail; Zadereev, Egor; Sokolova, Inna

    2016-01-01

    Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress. PMID:27896024

  11. Production of Bioethanol from Carrot Pomace Using the Thermotolerant Yeast Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Chi-Yang Yu; Bo-Hong Jiang; Kow-Jen Duan [Tatung University, Tapei, Taiwan (China). Department of Bioengineering

    2013-03-15

    Carrot pomace, a major agricultural waste from the juice industry, was used as a feedstock for bioethanol production by fermentation with the thermotolerant yeast Kluyveromyces marxianus. Treatment of the carrot pomace with Accellerase(TM) 1000 and pectinase at 50 °C for 84 h, resulted in conversion of 42% of its mass to fermentable sugars, mainly glucose, fructose, and sucrose. Simultaneous saccharification and fermentation (SSF) at 42 °C was performed on 10% (w/v) carrot pomace; the concentration of ethanol reached 18 g/L and the yield of ethanol from carrot pomace was 0.18 g/g. The highest ethanol concentration of 37 g/L was observed with an additional charge of 10% supplemented to the original 10% of carrot pomace after 12 h; the corresponding yield was 0.185 g/g. Our results clearly demonstrated the potential of combining a SSF process with thermotolerant yeast for the production of bioethanol using carrot pomace as a feedstock.

  12. Secondhand smoke induces hepatic apoptosis and fibrosis in hamster fetus.

    Science.gov (United States)

    Huang, Chien-Wei; Horng, Chi-Ting; Huang, Chih-Yang; Cho, Ta-Hsiung; Tsai, Yi-Chang; Chen, Li-Jeng; Hsu, Tsai-Ching; Tzang, Bor-Show

    2016-09-01

    Secondhand smoke (SHS) is an important health issue worldwide. Inhaling SHS during pregnancy could cause abnormalities in the internal tissues of newborns, which may then impair fetal development and even cause severe intrauterine damage and perinatal death. However, the understanding of cytopathic mechanisms of SHS by maternal passive smoking on fetus liver during pregnancy is still limited. This study analyzed the effects of high-dose SHS (SHSH) on fetus liver using a maternal passive smoking animal model. Experiments showed that hepatic matrix metalloproteinase-9 activity and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling-positive cells were significantly increased in livers from fetuses of hamsters treated with SHSH. Similarly, expressions of both extrinsic and intrinsic apoptotic molecules were significantly higher in livers from fetuses of hamsters exposed to SHSH. Additionally, significantly increased inflammatory proteins, including transforming growth factor β, inducible nitric oxide synthase, and interleukin 1β, and fibrotic signaling molecules, including phosphorylated Smad2/3, SP1, and α-smooth muscle actin, were observed in the fetus livers from hamsters treated with SHSH. This study revealed that SHSH not only increased apoptosis through intrinsic and extrinsic pathways in the livers of fetuses from hamsters exposed to SHSH but also augmented hepatic fibrosis via Smad2/3 signaling. © The Author(s) 2015.

  13. Proliferation of epithelial cell forming hamster palate during prenatal period

    Czech Academy of Sciences Publication Activity Database

    Buchtová, M.; Tichý, F.; Matulová, Petra; Míšek, Ivan

    2003-01-01

    Roč. 76, č. 4 (2003), s. 254-255 [Moravský morfologický den/4./. 11.06.2003, Brno] R&D Projects: GA ČR GA304/02/0448; GA ČR GP304/01/P021 Institutional research plan: CEZ:AV0Z5045916 Keywords : hamster Subject RIV: ED - Physiology

  14. Het effect van hamsterbeheer op de overwintering bij hamsters

    NARCIS (Netherlands)

    Beek, van der M.; Ligtenberg, H.; Haye, la M.J.J.

    2006-01-01

    De afgelopen decennia is het aantal hamsters (Cricetus cricetus) in Nederland sterk afgenomen. Door onderzoek te verrichten naar de levenscyclus en naar de effecten van agrarisch beheer is getracht de afname te verklaren en oplossingen aan te dragen. In voorjaar 2006 is een verkennend onderzoek

  15. Enhanced longevity in tau mutant Syrian hamsters, Mesocricetus auratus

    NARCIS (Netherlands)

    Oklejewicz, Malgorzata; Daan, Serge

    The single-gene mutation tau in the Syrian hamster shortens the circadian period by about 20% in the homozygous mutant and simultaneously increases the mass-specific metabolic rate by about 20%. Both effects might be expected to lead to a change in longevity. To test such expectations, the life span

  16. Bioavailability and disposition of solanine in rats and hamsters

    NARCIS (Netherlands)

    Groen K; Pereboom-de Fauw DPKH; Besamusca P; Beekhof PK; Speijers GJA; Derks HJGM

    1992-01-01

    The toxicokinetics of [3H]-alpha-solanine after oral (po) and intravenous (iv) administration in rats and hamsters were studied, in order to decide which is the most appropriate model in risk assessment studies. The iv dose was 54 mug/kg; the oral dose was 170 mug/kg. After iv administration, the

  17. Development of Taenia pisiformis in golden hamster (Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Maravilla Pablo

    2011-07-01

    Full Text Available Abstract The life cycle of Taenia pisiformis includes canines as definitive hosts and rabbits as intermediate hosts. Golden hamster (Mesocricetus auratus is a rodent that has been successfully used as experimental model of Taenia solium taeniosis. In the present study we describe the course of T. pisiformis infection in experimentally infected golden hamsters. Ten females, treated with methyl-prednisolone acetate were infected with three T. pisiformis cysticerci each one excised from one rabbit. Proglottids released in faeces and adults recovered during necropsy showed that all animals were infected. Eggs obtained from the hamsters' tapeworms, were assessed for viability using trypan blue or propidium iodide stains. Afterwards, some rabbits were inoculated with eggs, necropsy was performed after seven weeks and viable cysticerci were obtained. Our results demonstrate that the experimental model of adult Taenia pisiformis in golden hamster can replace the use of canines in order to study this parasite and to provide eggs and adult tapeworms to be used in different types of experiments.

  18. Early postnatal development of the South African hamster ...

    African Journals Online (AJOL)

    The South African Hamster Mystromys albicaudatus has been bred in the laboratory of the. Medical Ecology Centre since 1941. It is of interest taxonomically in that it is the sole repre- sentative left in Africa of the subfamily Cricetinae (Davis 1962). It has been used in Medical. Research on poliomyelitis, benign ...

  19. Comparative susceptibility of vero and baby hamster kidney cell ...

    African Journals Online (AJOL)

    Comparative susceptibility of vero and baby hamster kidney cell lines to PPR virus. ... Bulletin of Animal Health and Production in Africa ... The inoculated BHK and Vero cells supported the growth of the virus with syncytia formation more commonly observed in the BHK cells while vacuolation and cell disintegration were ...

  20. Early Postnatal Development of the South African Hamster ...

    African Journals Online (AJOL)

    The South African Hamster Mystromys albicaudatus has been bred in the laboratory of the Medical Ecology Centre since 1941. It is of interest taxonomically in that it is the sole representative left in Africa of the subfamily Cricetinae (Davis 1962). It has been used in Medical Research on poliomyelitis, benign histoplasmosis, ...

  1. Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climates

    Science.gov (United States)

    Danielle E. Marias; Frederick C. Meinzer; David R. Woodruff; Katherine A. McCulloh; David Tissue

    2016-01-01

    Temperature and the frequency and intensity of heat waves are predicted to increase throughout the 21st century. Germinant seedlings are expected to be particularly vulnerable to heat stress because they are in the boundary layer close to the soil surface where intense heating occurs in open habitats. We quantified leaf thermotolerance and whole-plant physiological...

  2. Validation of a PCR-based method for detection of food-borne thermotolerant Campylobacters in a multicenter collaborative trial

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Cook, N.; D'Agostino, M.

    2004-01-01

    A PCR-based method for rapid detection of food-borne thermotolerant campylobacters was evaluated through a collaborative trial with 12 laboratories testing spiked carcass rinse samples. The method showed an interlaboratory diagnostic sensitivity of 96.7% and a diagnostic specificity of 100...

  3. Genetically altering the expression of neutral trehalase gene affects conidiospore thermotolerance of the entomopathogenic fungus Metarhizium acridum

    Directory of Open Access Journals (Sweden)

    Peng Guoxiong

    2011-02-01

    Full Text Available Abstract Background The entomopathogenic fungus Metarhizium acridum has been used as an important biocontrol agent instead of insecticides for controlling crop pests throughout the world. However, its virulence varies with environmental factors, especially temperature. Neutral trehalase (Ntl hydrolyzes trehalose, which plays a role in environmental stress response in many organisms, including M. acridum. Demonstration of a relationship between Ntl and thermotolerance or virulence may offer a new strategy for enhancing conidiospore thermotolerance of entomopathogenic fungi through genetic engineering. Results We selected four Ntl over-expression and four Ntl RNA interference (RNAi transformations in which Ntl expression is different. Compared to the wild-type, Ntl mRNA expression was reduced to 35-66% in the RNAi mutants and increased by 2.5-3.5-fold in the over-expression mutants. The RNAi conidiospores exhibited less trehalase activity, accumulated more trehalose, and were much more tolerant of heat stress than the wild-type. The opposite effects were found in conidiospores of over-expression mutants compared to RNAi mutants. Furthermore, virulence was not altered in the two types of mutants compared to the wild type. Conclusions Ntl controlled trehalose accumulation in M. acridum by degrading trehalose, and thus affected conidiospore thermotolerance. These results offer a new strategy for enhancing conidiospore thermotolerance of entomopathogenic fungi without affecting virulence.

  4. Influence of physiological environment on the expression of thermotolerance in proliferating (P) and quiescent (Q) tumor cells

    International Nuclear Information System (INIS)

    Wallen, C.A.; Gutierrez, R.H.

    1987-01-01

    Alteration of the physiological environment of Q 66 and 67 mouse mammary tumor cells by placing them in either fresh, complete medium or a balanced salt solution supplemented with 24 mM glucose resulted in a significant increase in the time at 45 0 C necessary to measure cytotoxicity. The degree of increased resistance was dependent on the solution used to change the environment and the length of time the cells were allowed to equilibrate in this new environment. The aim of the present study is to determine if alterations in the Q cell environment has significant effects on the expression of thermotolerance. Pure P and Q cell populations of both 66 and 67 cell lines are exposed continuously to either 42 or 43 0 C and assayed for colony formation at various times for the development of thermotolerance. The comparison of thermotolerance development both in terms of time course and extent are measured in Q cells under 5 conditions: 1) normal, depleted medium (pH 6.8), 2) fresh, complete medium (pH 7.2), 3) balanced salt solution with 24 mM glucose (pH 7.2), 4) balanced salt solution with no glucose (pH 7.2), and 5) depleted medium supplemented with fresh serum (pH 6.8). These data have implications for the importance of Q cells in determining the outcome of clinical hyperthermia and the role of other stressors on the expression of thermotolerance

  5. Seasonal aspects of sleep in the Djungarian hamster

    Directory of Open Access Journals (Sweden)

    Deboer Tom

    2003-05-01

    Full Text Available Abstract Background Changes in photoperiod and ambient temperature trigger seasonal adaptations in the physiology and behaviour of many species, including the Djungarian hamster. Exposure of the hamsters to a short photoperiod and low ambient temperature leads to a reduction of the polyphasic distribution of sleep and waking over the light and dark period. In contrast, a long photoperiod enhances the daily sleep-wake amplitude leading to a decline of slow-wave activity in NREM sleep within the light period. It is unknown whether these changes can be attributed specifically to photoperiod and/or ambient temperature, or whether endogenous components are contributing factors. The influence of endogenous factors was investigated by recording sleep in Djungarian hamsters invariably maintained at a low ambient temperature and fully adapted to a short photoperiod. The second recording was performed when they had returned to summer physiology, despite the maintenance of the 'winter' conditions. Results Clear winter-summer differences were seen in sleep distribution, while total sleep time was unchanged. A significantly higher light-dark cycle modulation in NREM sleep, REM sleep and waking was observed in hamsters in the summer physiological state compared to those in the winter state. Moreover, only in summer, REM sleep episodes were longer and waking bouts were shorter during the light period compared to the dark period. EEG power in the slow-wave range (0.75–4.0 Hz in both NREM sleep and REM sleep was higher in animals in the summer physiological state than in those in the 'winter' state. In winter SWA in NREM sleep was evenly distributed over the 24 h, while in summer it decreased during the light period and increased during the dark period. Conclusion Endogenous changes in the organism underlie the differences in sleep-wake redistribution we have observed previously in hamsters recorded in a short and long photoperiod.

  6. Modeling the dual pacemaker system of the tau mutant hamster.

    Science.gov (United States)

    Oda, G A; Menaker, M; Friesen, W O

    2000-06-01

    Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.

  7. Mg2+ improves the thermotolerance of probiotic Lactobacillus rhamnosus GG, Lactobacillus casei Zhang and Lactobacillus plantarum P-8.

    Science.gov (United States)

    Yang, Y; Huang, S; Wang, J; Jan, G; Jeantet, R; Chen, X D

    2017-04-01

    Food-related carbohydrates and proteins are often used as thermoprotectants for probiotic lactobacilli during industrial production and processing. However, the effect of inorganic salts is rarely reported. Magnesium is the second-most abundant cation in bacteria, and commonly found in various foods. Mg 2+ homeostasis is important in Salmonella and has been reported to play a critical role in their thermotolerance. However, the role of Mg 2+ in thermotolerance of other bacteria, in particular probiotic bacteria, still remains a hypothesis. In this study, the effect of Mg 2+ on thermotolerance of probiotic lactobacilli was investigated in three well-documented probiotic strains, Lactobacillus rhamnosus GG, Lactobacillus casei Zhang and Lactobacillus plantarum P-8, in comparison with Zn 2+ and Na + . Concentrations of Mg 2+ between 10 and 50 mmol l -1 were found to increase the bacterial survival upon heat challenge. Remarkably, Mg 2+ addition at 20 mmol l -1 led to a 100-fold higher survival of L. rhamnosus GG upon heat challenge. This preliminary study also showed that Mg 2+ shortened the heat-induced extended lag time of bacteria, which indicated the improvement in bacterial recovery from thermal injury. In order to improve the productivity and stability of live probiotics, extensive investigations have been carried out to improve thermotolerance of probiotics. However, most of these studies focused on the effects of carbohydrates, proteins or amino acids. The roles of inorganic salts in various food materials, which have rarely been reported, should be considered when incorporating probiotics into these foods. In this study, Mg 2+ was found to play a significant role in the thermotolerance of probiotic lactobacilli. A novel strategy may be available in the near future by employing magnesium salts as protective agents of probiotics during manufacturing process. © 2017 The Society for Applied Microbiology.

  8. Sensibility of the hamster (Cricetus auratus to the Treponema pertenue

    Directory of Open Access Journals (Sweden)

    F. Nery-Guimarães

    1955-05-01

    Full Text Available In two experiments, 8 Hamsters inoculated with material from yaws lesions (Treponema pertenue, developed skin lesions considered specific by their clinical and histopathological aspects and by the presence of treponemae. These lesions appeared on the scrotumm, testicle, prepuce, anus, tail, muzzle, back and hinders paws (palm surface. In the internal organs no treponemae were found in direct examinations and inoculation of brain, spleen and lymph node. The incubation period was of 35 days for the testicle, 55 days for the scrotum and 107 days for peritoneal cavity inoculation. Positive sub-inoculations were obtained. The serum reactions (Qasserman's and Kahn's were negative in all 5 tested Hamsters. Out of 4 normal females matched to infected males two developed nasal lesions resulting from direct contact. Apparently the genital lesions hindered copulation. Hamsters are very well suited for an experimental study of yaws.Em 2 experiências, 8 Hamsters inoculados com material direto de lesões boubáticas (Treponema pertenue, desenvolveram lesões cutâneas consideradas específicas, pelo aspecto clínico e histopatológico e pela presentça de treponemas. Essas lesões se manifestaram no escrôto, testículo, prepúcio, anus, cauda, focinho, dorso e patas posteriores (face palmar. Nos órgãos internos não foram vistos treponemas ao exame direto e, uma vez, por inoculação de cérebro, baço e gânglio linfático. O período incubativo foi de 35 dias pela via testicular, 55 dias pela via escrotal e 107 dias pela via peritonial. Foram obtidas sub-inoculações positivas para Hamsters normais. As experiências continuam. De 4 fêmeas normais, acasaladas com 4 hamsters infectados apenas 2 mostraram lesões positivas resultantes de contágio direto. Aparentemente, não houve copulação e, se esta ocorreu, não determinou fecundação.

  9. Isolation and cross-sensitivity of X-ray-sensitive mutants of V79-4 hamster cells

    International Nuclear Information System (INIS)

    Jones, N.J.; Cox, R.; Thacker, J.

    1987-01-01

    The V79-4 Chinese hamster line was mutagenized and surviving clones screened for X-ray sensitivity using a replica microwell technique. One slightly sensitive clone and 3 clearly sensitive clones were isolated from approximately 5000 screened, and designated irs 1 to irs 4. The 3 more sensitive clones showed different responses to the genotoxic agents mitomycin C (MMC), ethyl methanesulphonate (EMS) and ultraviolet light (UV). irs 1 showed considerable sensitivity to all the agents tested, in the order MMC >> EMS > UV. irs 2 and irs 3 had similar sensitivities to EMS and to UV (EMS > UV) but irs 3 was more sensitive than irs 2 to MMC. None of these mutants is identical in phenotype to previously published mutants. (Auth.)

  10. Understanding the mechanisms of ATPase beta family genes for cellular thermotolerance in crossbred bulls.

    Science.gov (United States)

    Deb, Rajib; Sajjanar, Basavaraj; Singh, Umesh; Alex, Rani; Raja, T V; Alyethodi, Rafeeque R; Kumar, Sushil; Sengar, Gyanendra; Sharma, Sheetal; Singh, Rani; Prakash, B

    2015-12-01

    Na+/K+-ATPase is an integral membrane protein composed of a large catalytic subunit (alpha), a smaller glycoprotein subunit (beta), and gamma subunit. The beta subunit is essential for ion recognition as well as maintenance of the membrane integrity. Present study was aimed to analyze the expression pattern of ATPase beta subunit genes (ATPase B1, ATPase B2, and ATPase B3) among the crossbred bulls under different ambient temperatures (20-44 °C). The present study was also aimed to look into the relationship of HSP70 with the ATPase beta family genes. Our results demonstrated that among beta family genes, transcript abundance of ATPase B1 and ATPase B2 is significantly (P ATPase Β1, ATPase B2, and ATPase B3 is highly correlated (P ATPase beta family genes for cellular thermotolerance in cattle.

  11. High alcohol production by solid substrate fermentation from starchy substrates using thermotolerant Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Sree, N.K.; Sridhar, M.; Suresh, K.; Rao, L.V. [Department of Microbiology, Osmania University, Hyderabad 500007, Andhra Pradesh (India)

    1999-06-01

    Solid Substrate Fermentation system (SSF) was used to produce ethanol from various starchy substrates like sweet sorghum, sweet potato, wheat flour, rice starch, soluble starch and potato starch using thermotolerant yeast isolate (VS{sub 3}) by simultaneous saccharification and fermentation process. Alcohol produced was estimated by gas chromatography after an incubation time of 96 hrs at 37 C and 42 C. More ethanol was produced from rice starch and sweet sorghum. The maximum amount of ethanol produced from these substrates using VS{sub 3} was 10 g/100 g and 3.5 g/100 g substrate (rice starch) and 8.2 g and 7.5 g/100 g substrate (sweet sorghum) at 37 C and 42 C respectively. (orig.) With 2 figs., 1 tab., 12 refs.

  12. Screening and application of thermotolerant microorganisms and their flocculant for treatment of palm oil mill effluent

    Directory of Open Access Journals (Sweden)

    Saithong Kaewchai

    2002-07-01

    Full Text Available Among fifteen thermotolerant polymer-producing isolates, three strains SM 29, WD 90, and SM 38 produced polymer posessing very high flocculating activities (24.81, 14.63 and 10.84, respectively and flocculation rates (94.29, 90.69 and 87.84, respectively. These three strains were identified to be Bacillus subtilis WD90, Bacillus subtilis SM 29, and Enterobacter agglomerans SM 38. Treatment of palm oil mill effluent (POME by these three selected strains under aerobic condition at 45ºC for 48 h revealed that neither oil separation nor flocculation of solids was observed. However, all three strains were able to decolorize the POME from dark brown to very light yellow. Flocculant produced from the three selected isolates could not separate the suspended solids and oil from the POME.

  13. Hamsters' (Mesocricetus auratus) memory in a radial maze analog: the role of spatial versus olfactory cues.

    Science.gov (United States)

    Tonneau, François; Cabrera, Felipe; Corujo, Alejandro

    2012-02-01

    The golden hamster's (Mesocricetus auratus) performance on radial maze tasks has not been studied a lot. Here we report the results of a spatial memory task that involved eight food stations equidistant from the center of a circular platform. Each of six male hamsters depleted the food stations along successive choices. After each choice and a 5-s retention delay, the hamster was brought back to the center of the platform for the next choice opportunity. When only one baited station was left, the platform was rotated to evaluate whether olfactory traces guided hamsters' choices. Results showed that despite the retention delay hamsters performed above chance in searching for food. The choice distributions observed during the rotation probes were consistent with spatial memory and could be explained without assuming guidance by olfactory cues. The radial maze analog we devised could be useful in furthering the study of spatial memory in hamsters.

  14. Prevalence and Antibiotic Resistance of Thermotolerant Campylobacter spp. in Chicken Meat Sold in İstanbul

    Directory of Open Access Journals (Sweden)

    Serkan Kemal BÜYÜKÜNAL

    2017-07-01

    Full Text Available Campylobacter spp. are some of the most common causes of bacterial diarrhea in humans worldwide. They are mainly considered as foodborne pathogens that are found in raw or undercooked poultry and serve as an important source of sporadic campylobacteriosis. The present study was aimed to determine the prevalence and the antimicrobial resistance patterns of thermotolerant Campylobacter spp. in chicken meat. A total of 176 samples of chicken meat were analyzed using PCM and BAX® system. The samples analyzed included: 56 samples of whole chicken, 27 samples of chicken breast, 33 samples of chicken thigh, 25 samples of chicken drumstick and 35 samples of chicken wings. Samples of all the fresh chicken meat sold in İstanbul were randomly purchased from different major supermarkets in their original, individual packages. Laboratory analyses to detect thermotolerant Campylobacter spp. were performed in accordance with the ISO 10272-1, 2006 standard (qualitative analysis. API® Campy (BioMerieux, Marcy-l’Etoile, France was used for the confirmation of presumptive colonies. Campylobacter isolates were subjected to antimicrobial susceptibility tests by the disc diffusion method as recommended by the National Committee for Clinical Laboratory Standards. Zones of growth inhibition were evaluated according to the NCCLS standards. Using PCM, the prevalence of C. coli, C. jejuni and C. lari was determined as 15.34, 8.52 and 1.7%, respectively. However, using BAX® system, the prevalence was determined as 15.90, 18.75 and 1.7% for C. coli, C. jejuni and C. lari, respectively. C. coli was resistant to nalidixic acid (78.57%, ofloxacin (14.29% norfloxacin (10.71% and ampicillin (10.71%. But the highest resistance was observed to nalidixic acid (90.91% for C. jejuni and (100% for C. lari. In conclusion, considering the public health, chicken meat is a common source for Campylobacter strains and antibiotics should be used carefully in veterinary medicine.

  15. Identification of Heat Shock Transcription Factor Genes Involved in Thermotolerance of Octoploid Cultivated Strawberry.

    Science.gov (United States)

    Liao, Wan-Yu; Lin, Lee-Fong; Jheng, Jing-Lian; Wang, Chun-Chung; Yang, Jui-Hung; Chou, Ming-Lun

    2016-12-17

    Heat shock transcription factors (HSFs) are mainly involved in the activation of genes in response to heat stress as well as other abiotic and biotic stresses. The growth, development, reproduction, and yield of strawberry are strongly limited by extreme temperatures and droughts. In this study, we used Illumina sequencing and obtained transcriptome data set from Fragaria × ananassa Duchessne cv. Toyonoka. Six contigs and three unigenes were confirmed to encode HSF proteins (FaTHSFs). Subsequently, we characterized the biological functions of two particularly selected unigenes, FaTHSFA2a and FaTHSFB1a , which were classified into class A2 and B HSFs, respectively. Expression assays revealed that FaTHSFA2a and FaTHSFB1a expression was induced by heat shock and correlated well with elevated ambient temperatures. Overexpression of FaTHSFA2a and FaTHSFB1a resulted in the activation of their downstream stress-associated genes, and notably enhanced the thermotolerance of transgenic Arabidopsis plants. Besides, both FaTHSFA2a and FaTHSFB1a fusion proteins localized in the nucleus, indicating their similar subcellular distributions as transcription factors. Our yeast one-hybrid assay suggested that FaTHSFA2a has trans-activation activity, whereas FaTHSFB1a expresses trans-repression function. Altogether, our annotated transcriptome sequences provide a beneficial resource for identifying most genes expressed in octoploid strawberry. Furthermore, HSF studies revealed the possible insights into the molecular mechanisms of thermotolerance, thus rendering valuable molecular breeding to improve the tolerance of strawberry in response to high-temperature stress.

  16. Tuning Chocolate Flavor through Development of Thermotolerant Saccharomyces cerevisiae Starter Cultures with Increased Acetate Ester Production.

    Science.gov (United States)

    Meersman, Esther; Steensels, Jan; Struyf, Nore; Paulus, Tinneke; Saels, Veerle; Mathawan, Melissa; Allegaert, Leen; Vrancken, Gino; Verstrepen, Kevin J

    2016-01-15

    Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled fermentations, the fermentation involved in the production of chocolate is still a spontaneous process that relies on the natural microbiota at cocoa farms. However, recent studies indicate that certain thermotolerant Saccharomyces cerevisiae cultures can be used as starter cultures for cocoa pulp fermentation. In this study, we investigate the potential of specifically developed starter cultures to modulate chocolate aroma. Specifically, we developed several new S. cerevisiae hybrids that combine thermotolerance and efficient cocoa pulp fermentation with a high production of volatile flavor-active esters. In addition, we investigated the potential of two strains of two non-Saccharomyces species that produce very large amounts of fruity esters (Pichia kluyveri and Cyberlindnera fabianii) to modulate chocolate aroma. Gas chromatography-mass spectrometry (GC-MS) analysis of the cocoa liquor revealed an increased concentration of various flavor-active esters and a decrease in spoilage-related off-flavors in batches inoculated with S. cerevisiae starter cultures and, to a lesser extent, in batches inoculated with P. kluyveri and Cyb. fabianii. Additionally, GC-MS analysis of chocolate samples revealed that while most short-chain esters evaporated during conching, longer and more-fat-soluble ethyl and acetate esters, such as ethyl octanoate, phenylethyl acetate, ethyl phenylacetate, ethyl decanoate, and ethyl dodecanoate, remained almost unaffected. Sensory analysis by an expert panel confirmed significant differences in the aromas of chocolates produced with different starter cultures. Together, these results show that the selection of different yeast cultures opens novel avenues for modulating chocolate flavor. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Screening of thermotolerant microorganisms and application for oil separation from palm oil mill wastewater

    Directory of Open Access Journals (Sweden)

    Aran H-Kittikun

    2007-05-01

    Full Text Available The characteristics of palm oil mill wastewater (POMW were brown color, pH 3.8-4.3, temperature 48-55oC, total solids 68.2-82.1 g/l, suspended solids 26.2-65.6 g/l, oil and grease 19.1-25.1 g/l, COD 49.9-160.7g/l and BOD 32.5-75.3 g/l. After centrifugation (3,184 xg of 50 ml POMW for 10 min, the POMW was separated into 3 layers: top (oil, middle (supernatant and bottom layer (sediment. The sediment containeddry weight 1.19 g and oil and grease 1.07 g. In order to release oil and grease trapped in palm fiber debris in the POMW, cellulase- and/or xylanase-enzyme-producing and thermotolerant microorganisms wereisolated. The isolates SO1 and SO2 were isolated from soil near the first anaerobic pond of the palm oil mill. They were aerobic, Gram positive, rod shaped, thermotolerant microorganisms and produced cellulase 12.11 U/ml (3 days and 7.2 U/ml (4 days, and xylanase 50.98 U/ml (4 days and 20.42 U/ml (4 days, respectivelyin synthetic medium containing carboxymethycellulose as a carbon source. When these 2 isolates were added into the steriled POMW under shaking condition for 7 days, after centrifugation at 3,184 xg the isolate SO1gave the better % reduction of dry weight (64.66 % and of oil and grease in the bottom layer (85.32 % of the POMW.

  18. Tuning Chocolate Flavor through Development of Thermotolerant Saccharomyces cerevisiae Starter Cultures with Increased Acetate Ester Production

    Science.gov (United States)

    Meersman, Esther; Steensels, Jan; Struyf, Nore; Paulus, Tinneke; Saels, Veerle; Mathawan, Melissa; Allegaert, Leen; Vrancken, Gino

    2015-01-01

    Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled fermentations, the fermentation involved in the production of chocolate is still a spontaneous process that relies on the natural microbiota at cocoa farms. However, recent studies indicate that certain thermotolerant Saccharomyces cerevisiae cultures can be used as starter cultures for cocoa pulp fermentation. In this study, we investigate the potential of specifically developed starter cultures to modulate chocolate aroma. Specifically, we developed several new S. cerevisiae hybrids that combine thermotolerance and efficient cocoa pulp fermentation with a high production of volatile flavor-active esters. In addition, we investigated the potential of two strains of two non-Saccharomyces species that produce very large amounts of fruity esters (Pichia kluyveri and Cyberlindnera fabianii) to modulate chocolate aroma. Gas chromatography-mass spectrometry (GC-MS) analysis of the cocoa liquor revealed an increased concentration of various flavor-active esters and a decrease in spoilage-related off-flavors in batches inoculated with S. cerevisiae starter cultures and, to a lesser extent, in batches inoculated with P. kluyveri and Cyb. fabianii. Additionally, GC-MS analysis of chocolate samples revealed that while most short-chain esters evaporated during conching, longer and more-fat-soluble ethyl and acetate esters, such as ethyl octanoate, phenylethyl acetate, ethyl phenylacetate, ethyl decanoate, and ethyl dodecanoate, remained almost unaffected. Sensory analysis by an expert panel confirmed significant differences in the aromas of chocolates produced with different starter cultures. Together, these results show that the selection of different yeast cultures opens novel avenues for modulating chocolate flavor. PMID:26590272

  19. Evaluation of Aegilops tauschii and Aegilops speltoides for acquired thermotolerance: Implications in wheat breeding programmes.

    Science.gov (United States)

    Hairat, Suboot; Khurana, Paramjit

    2015-10-01

    Severe and frequent heat waves are predicted in the near future having dramatic and far-reaching ecological and social impact. The aim of this study was to examine acquired thermotolerance of two Aegilops species: Aegilops tauschii and Aegilops speltoides and study their potential adaptive mechanisms. The effect of two episodes of high heat stress (45 °C/12 h) with a day of recovery period was investigated on their physiology. As compared to A. speltoides, A. tauschii suffered less inhibition of photosystem II efficiency and net photosynthetic rate (Pn). Although A. tauschii showed nearly complete recovery of PSII, the adverse effect was more pronounced in A. speltoides. Measurement of the minimum fluorescence (Fo) versus temperature curves revealed a higher inflection temperature of Fo for A. tauschii than A. speltoides, reflecting greater thermo stability of the photosynthetic apparatus. Absorbed light energy distribution revealed that A. speltoides showed increased steady state fluorescence and a lower absorbed light allocated to photosynthetic chemistry (ɸPSII) relative to A. tauschii. However, A. tauschii showed higher ability to scavenge free radicals as compared to A. speltoides. This was further validated by higher expression of ascorbate peroxidase gene. These results suggest that A. tauschii showed faster recovery and a better thermostability of its photosynthetic apparatus under severe stress conditions along with a better regulation of energy channeling of PSII complexes to minimize oxidative damage and thus retains greater capability of carbon assimilation. These factors aid in imparting a greater heat tolerance to A. tauschii as compared to A. speltoides and thus make it a better candidate for alien species introgression in wheat breeding programs for thermotolerance in wheat. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Root Antioxidant Mechanisms in Relation to Root Thermotolerance in Perennial Grass Species Contrasting in Heat Tolerance.

    Directory of Open Access Journals (Sweden)

    Yi Xu

    Full Text Available Mechanisms of plant root tolerance to high temperatures through antioxidant defense are not well understood. The objective of this study was to investigate whether superior root thermotolerance of heat-tolerant Agrostis scabra relative to its congeneric heat-sensitive Agrostis stolonifera was associated with differential accumulation of reactive oxygen species and antioxidant scavenging systems. A. scabra 'NTAS' and A. stolonifera 'Penncross' plants were exposed to heat stress (35/30°C, day/night in growth chambers for 24 d. Superoxide (O2(- content increased in both A. stolonifera and A. scabra roots under heat stress but to a far lesser extent in A. scabra than in A. stolonifera. Hydrogen peroxide (H2O2 content increased significantly in A. stolonifera roots but not in A. scabra roots responding to heat stress. The content of antioxidant compounds (ascorbate and glutathione did not differ between A. stolonifera and A. scabra under heat stress. Enzymatic activity of superoxide dismutase was less suppressed in A. scabra than that in A. stolonifera under heat stress, while peroxidase and catalase were more induced in A. scabra than in A. stolonifera. Similarly, their encoded transcript levels were either less suppressed, or more induced in A. scabra roots than those in A. stolonifera during heat stress. Roots of A. scabra exhibited greater alternative respiration rate and lower cytochrome respiration rate under heat stress, which was associated with suppression of O2(- and H2O2 production as shown by respiration inhibitors. Superior root thermotolerance of A. scabra was related to decreases in H2O2 and O2(- accumulation facilitated by active enzymatic antioxidant defense systems and the maintenance of alternative respiration, alleviating cellular damages by heat-induced oxidative stress.

  1. Rapid induction of glomerular lipidosis in APA hamsters by streptozotocin.

    Science.gov (United States)

    Han, J. S.; Sugawara, Y.; Doi, K.

    1992-01-01

    The pathology of male Syrian hamsters of APA strain which were injected intraperitoneally with 40 mg/kg body weight of streptozotocin (SZ) at 2 months of age was examined. It showed long-lasting prominent hyperglycaemia and hyperlipidaemia with glucosuria and the development of glomerular lipidosis from 1 month after SZ-injection (1 MAI). Glomerular lesions were restricted to the juxtamedullary cortex at 1 MAI and then extended to the subcapsular cortex. At 3 MAI, glomerular lesions were characterized by focal segmental glomerulosclerosis showing segmental expansion of the mesangial area due to an increase of basement membrane-like material and mesangial cells with lipid droplets and foam cells. SZ-induced diabetic APA hamsters will be a useful model for the investigation of glomerular lipidosis and focal segmental glomerulosclerosis. Images Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:1533531

  2. Cystolithiasis in a Syrian hamster: a different outcome

    Directory of Open Access Journals (Sweden)

    D. Petrini

    2016-08-01

    Full Text Available A 14-month-old intact male Syrian hamster was admitted for lethargy and hematuria. A total body radiographic image and abdominal ultrasonography showed the presence of a vesical calculus. During cystotomy, a sterile urine sample was obtained and sent to the diagnostic laboratory along with the urolith for analysis. Urine culture was found negative for bacterial growth, and the urolith was identified as a calcium-oxalate stone. Diet supplementation with palmitoylethanolamide, glucosamine and hesperidin was adopted the day after discharge. One year follow up revealed no presence of vesical calculi. Although this is the report of a single clinical case, this outcome differs from the results reported in the literature characterized by recurrences after few months. Considering the positive outcome and the beneficial properties of palmitoylethanolamide, glucosamine, and hesperidin, these nutritional elements in Syrian hamsters, are recommended to reduce recurrence after surgical treatment of urolithiasis.

  3. [Investigation on the prevalence of gastrointestinal parasites in pet hamsters].

    Science.gov (United States)

    Lv, Chao-Chao; Feng, Chao; Qi, Meng; Yang, Hong-Yu; Jian, Fu-Chun; Ning, Chang-Shen; Zhang, Long-Xian

    2009-06-01

    One hundred and fifty-three fecal samples of pet hamsters (Mesocricetus auratus, Phodopus sungorus, P. campbelli and P. roborovskii) were collected from a pet-market in Zhengzhou, and examined by Sheather's sugar flotation, modified acid-fast staining and Lugol's iodine-solution staining. The prevalence of parasites was 70.7% (41/58), 96.7% (59/61), 83.9% (26/31), and 100% (3/3) respectively, with an overall prevalence of 84.3%. Eggs, cysts or oocysts of Cryptosporidium sp. (15.0%), Giardia sp. (22.2%), coccidian (2.0%), Hymenolepis nana (31.4%), Hymenolepis diminuta (25.5%), Syphacia spp. (41.8%), Aspiculuris tetraptera (7.2%) and undetermined Trichurata nematode (18.3%) were found from the samples. The results suggest that pet hamsters may be infected and transmit several zoonotic parasites.

  4. Autoradiographic images in the hamster cheek pouch oral cancer model

    International Nuclear Information System (INIS)

    Portu, A.; Molinari, A.J.; Schwint, A.; Saint Martin, G.; Thorp, S.; Pozzi, E.C.C.; Curotto, P.

    2013-01-01

    The aim of this work is to summarize the autoradiographic study performed to samples from different protocols of the hamster cheek pouch oral cancer model. The qualitative analysis of histological and autoradiographic images, together with the determination of the boron concentration in the different structures of tumor, premalignant tissue and normal tissue contributed to the knowledge of the microdistribution of boron compounds. Besides, the study led to the optimization of the autoradiography technique applied to BNCT (Boron Neutron Capture Therapy). (author)

  5. Equine herpesvirus type 1 induces both neurological and respiratory disease in Syrian hamsters.

    Science.gov (United States)

    Mesquita, Leonardo Pereira; Arévalo, Andressa Ferrari; Zanatto, Dennis A; Miyashiro, Samantha Ive; Cunha, Elenice Maria Sequetin; de Souza, Maria do Carmo Custódio; Villalobos, Eliana Monteforte Cassaro; Mori, Cláudia Madalena Cabrera; Maiorka, Paulo César; Mori, Enio

    2017-05-01

    The equine herpesvirus type 1 (EHV-1) is an important cause of myeloencephalopathy and respiratory disease in horses. Animal models for EHV-1 infection have been specially developed using mice and Syrian hamsters (Mesocricetus auratus). However, few studies have attempted to evaluate the pathogenesis of EHV-1 infection in the central nervous system (CNS) and respiratory system of hamsters. Therefore, the aim of this study was to evaluate the pathogenesis of four Brazilian EHV-1 strains within the CNS and lungs of Syrian hamsters. Hamsters intranasally infected with A4/72, A9/92, A3/97, and Iso/72 EHV-1 strains developed severe neurological and respiratory signs and died during acute EHV-1 infection within 3 to 5days post-inoculation. However, neurological signs were more severe in A4/72 and A9/92-infected hamsters, whereas respiratory signs were more prominent in A3/97 and Iso/72-infected hamsters. In the latter, lesions in the CNS were predominantly inflammatory, whereas in A4/72 and A9/92-infected hamsters, neuronal and liquefactive necrosis were the predominant lesions. EHV-1 infected hamsters also developed an interstitial pneumonia with infiltration of alveolar septa by macrophages, neutrophils, and lymphocytes, with the exception of A9/92-infected hamsters, which developed severe hemorrhages within the airways. EHV-1 antigens were detected along with CNS and pulmonary lesions. EHV-1 was also recovered from CNS of all infected hamsters, whereas the virus was recovered from the lungs of A4/72, A9/92, and Iso/72-infected hamsters. Brazilian EHV-1 strains caused both severe CNS and respiratory disease in hamsters, thus making this species an interesting model for EHV-1 infection in the CNS and respiratory system. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils

    Science.gov (United States)

    Musacchia, X. J.

    1973-01-01

    Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.

  7. Female-biased anorexia and anxiety in the Syrian hamster.

    Science.gov (United States)

    Shannonhouse, John L; Fong, Li An; Clossen, Bryan L; Hairgrove, Ross E; York, Daniel C; Walker, Benjamin B; Hercules, Gregory W; Mertesdorf, Lauren M; Patel, Margi; Morgan, Caurnel

    2014-06-22

    Anorexia and anxiety cause significant mortality and disability with female biases and frequent comorbidity after puberty, but the scarcity of suitable animal models impedes understanding of their biological underpinnings. It is reported here that in adult or weanling Syrian hamsters, relative to social housing (SH), social separation (SS) induced anorexia characterized as hypophagia, weight loss, reduced adiposity, and hypermetabolism. Following anorexia, SS increased reluctance to feed, and thigmotaxis, in anxiogenic environments. Importantly, anorexia and anxiety were induced post-puberty with female biases. SS also reduced hypothalamic corticotrophin-releasing factor mRNA and serum corticosteroid levels assessed by RT-PCR and RIA, respectively. Consistent with the view that sex differences in adrenal suppression contributed to female biases in anorexia and anxiety by disinhibiting neuroimmune activity, SS elevated hypothalamic interleukin-6 and toll-like receptor 4 mRNA levels. Although corticosteroids were highest during SH, they were within the physiological range and associated with juvenile-like growth of white adipose, bone, and skeletal muscle. These results suggest that hamsters exhibit plasticity in bioenergetic and emotional phenotypes across puberty without an increase in stress responsiveness. Thus, social separation of hamsters provides a model of sex differences in anorexia and anxiety during adulthood and their pathogeneses during adolescence. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Melanin content of hamster tissues, human tissues, and various melanomas

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.P.; Fairchild, R.G.; Slatkin, D.N.; Greenberg, D.; Packer, S.; Atkins, H.L.; Hannon, S.J.

    1981-02-01

    Melanin content (percentage by weight) was determined in both pigmented and nonpigmented tissues of Syrian golden hamsters bearing Greene melanoma. Melanin content was also measured in various other melanoma models (B-16 in C57 mice, Harding-Passey in BALB/c mice, and KHDD in C3H mice) and in nine human melanomas, as well as in selected normal tissues. The purpose was to evaluate the possible efficacy of chlorpromazine, which is known to bind to melanin, as a vehicle for boron transport in neutron capture therapy. Successful therapy would depend upon selective uptake and absolute concentration of borated compounds in tumors; these parameters will in turn depend upon melanin concentration in melanomas and nonpigmented ''background'' tissues. Hamster whole eyes, hamster melanomas, and other well-pigmented animal melanomas were found to contain 0.3 to 0.8% melanin by weight, whereas human melanomas varied from 0.1 to 0.9% (average, 0.35%). Other tissues, with the exception of skin, were lower in content by a factor of greater than or equal to30. Melanin pigment was extracted from tissues, and the melanin content was determined spectrophotometrically. Measurements were found to be sensitive to the presence of other proteins. Previous procedures for isolating and quantifying melanin often neglected the importance of removing proteins and other interfering nonmelanic substances.

  9. Effects of hyperthermia on the hamster immune system

    International Nuclear Information System (INIS)

    Gangavalli, R.; Cain, C.A.; Tompkins, W.A.F.

    1984-01-01

    In previous studies, the authors have shown that hyperthermia can enhance antibody-complement chytotoxicity of hamster and human tumor cells. Moreover, whole body microwave exposure of hamsters resulted in activation of peritoneal macrophages to a viricidal state and transient suppression of natural killer (NK) cell activity. In this study, the authors compare the effects of whole body heating by microwaves or by an environmental chamber (hot air) on the hamster immune system. Microwave exposure (25mW/cm/sup 2/; 1 hr) caused viricidal activation of peritoneal macrophages which resulted in restriction of vaccinia and vesicular stomatitis virs (VSV) growth. However, heating in an environmental chamber (41 0 C; 1 hr) did not activate macrophages to a viricidal state. Both microwave and hot air hyperthermia caused significant augmentation of antibody producing spleen cell response to sheep red blood cells (SRBC), using the Jerne hymolytic plaque assay, four days post exposure and immunization with SRBC. Natural killer spleen cell cytotoxicity was suppressed by microwave and hot air hyperthermia showing that NK lymphocytes are extremely sensitive to changes in temperature. These alterations in cellular immune response due to hyperthermia could be of significance in treatment of tumors and viral infections

  10. Triterpenic Acids Present in Hawthorn Lower Plasma Cholesterol by Inhibiting Intestinal ACAT Activity in Hamsters.

    Science.gov (United States)

    Lin, Yuguang; Vermeer, Mario A; Trautwein, Elke A

    2011-01-01

    Hawthorn (Crataegus pinnatifida) is an edible fruit used in traditional Chinese medicine to lower plasma lipids. This study explored lipid-lowering compounds and underlying mechanisms of action of hawthorn. Hawthorn powder extracts inhibited acylCoA:cholesterol acyltransferase (ACAT) activity in Caco-2 cells. The inhibitory activity was positively associated with triterpenic acid (i.e., oleanolic acid (OA) and ursolic acid (UA)) contents in the extracts. Cholesterol lowering effects of hawthorn and its potential additive effect in combination with plant sterol esters (PSE) were further studied in hamsters. Animals were fed a semi-synthetic diet containing 0.08% (w/w) cholesterol (control) or the same diet supplemented with (i) 0.37% hawthorn dichloromethane extract, (ii) 0.24% PSE, (iii) hawthorn dichloromethane extract (0.37%) plus PSE (0.24%) or (iv) OA/UA mixture (0.01%) for 4 weeks. Compared to the control diet, hawthorn, PSE, hawthorn plus PSE and OA/UA significantly lowered plasma non-HDL (VLDL + LDL) cholesterol concentrations by 8%, 9%, 21% and 6% and decreased hepatic cholesterol ester content by 9%, 23%, 46% and 22%, respectively. The cholesterol lowering effects of these ingredients were conversely associated with their capacities in increasing fecal neutral sterol excretion. In conclusion, OA and UA are responsible for the cholesterol lowering effect of hawthorn by inhibiting intestinal ACAT activity. In addition, hawthorn and particularly its bioactive compounds (OA and UA) enhanced the cholesterol lowering effect of plant sterols.

  11. Triterpenic Acids Present in Hawthorn Lower Plasma Cholesterol by Inhibiting Intestinal ACAT Activity in Hamsters

    Directory of Open Access Journals (Sweden)

    Yuguang Lin

    2011-01-01

    Full Text Available Hawthorn (Crataegus pinnatifida is an edible fruit used in traditional Chinese medicine to lower plasma lipids. This study explored lipid-lowering compounds and underlying mechanisms of action of hawthorn. Hawthorn powder extracts inhibited acylCoA:cholesterol acyltransferase (ACAT activity in Caco-2 cells. The inhibitory activity was positively associated with triterpenic acid (i.e., oleanolic acid (OA and ursolic acid (UA contents in the extracts. Cholesterol lowering effects of hawthorn and its potential additive effect in combination with plant sterol esters (PSE were further studied in hamsters. Animals were fed a semi-synthetic diet containing 0.08% (w/w cholesterol (control or the same diet supplemented with (i 0.37% hawthorn dichloromethane extract, (ii 0.24% PSE, (iii hawthorn dichloromethane extract (0.37% plus PSE (0.24% or (iv OA/UA mixture (0.01% for 4 weeks. Compared to the control diet, hawthorn, PSE, hawthorn plus PSE and OA/UA significantly lowered plasma non-HDL (VLDL + LDL cholesterol concentrations by 8%, 9%, 21% and 6% and decreased hepatic cholesterol ester content by 9%, 23%, 46% and 22%, respectively. The cholesterol lowering effects of these ingredients were conversely associated with their capacities in increasing fecal neutral sterol excretion. In conclusion, OA and UA are responsible for the cholesterol lowering effect of hawthorn by inhibiting intestinal ACAT activity. In addition, hawthorn and particularly its bioactive compounds (OA and UA enhanced the cholesterol lowering effect of plant sterols.

  12. Prevalence of intestinal parasites in hamsters and rabbits in some pet shops of Turkey.

    Science.gov (United States)

    Sürsal, Neslihan; Gökpinar, Sami; Yildiz, Kader

    2014-06-01

    In this study, we aimed to determine the parasite species carried by hamsters and rabbits purchased from some commercial pet shops in Turkey. For this purpose, the fecal samples of clinically healthy Syrian hamsters, dwarf hamsters, and crossbred rabbits were collected from 22 pet shops randomly selected in Ankara and Kirikkale provinces, located in Central Anatolia Region of Turkey. The fecal samples were examined with centrifuge flotation technique using saturated salt solution. Parasitic infection rate was 57.5% in dwarf hamsters, 54.9% in Syrian hamsters, and 56.3% in crossbreed rabbits. Trichurid eggs were the most prevalent parasite in the feces of Syrians hamsters (28.1%). The other parasites of Syrian hamsters were as follows: Eimeria spp. oocysts (15.4%) and the eggs of H. nana (11.2%), Syphacia spp. (11%). and Aspiculuris spp. (5.6 %). Only trichurid eggs were observed in the fecal samples of dwarf hamsters (51.5%). Oocysts of Eimeria spp. (52.7%) and the eggs of P. ambiguus (3.6%) were detected in the feces of rabbits. Within the scope of this study, the detection of H. nana eggs, a zoonotic parasite, in the feces of Syrian hamster was quite remarkable for public health.

  13. Chinese Cooking.

    Science.gov (United States)

    Kane, Tony

    This unit, intended for secondary level students, is a general introduction to Chinese cooking. It is meant to inform students about the origins of Chinese cooking styles in their various regional manifestations, and it can be used to discuss how and why different cultures develop different styles of cooking. The first part of the unit, adapted…

  14. Production of pullulan by a thermotolerant aureobasidium pullulans strain in non-stirred fed batch fermentation process.

    Science.gov (United States)

    Singh, Ranjan; Gaur, Rajeeva; Tiwari, Soni; Gaur, Manogya Kumar

    2012-07-01

    Total 95 isolates of Aureobasidium pullulans were isolated from different flowers and leaves samples, out of which 11 thermotolerant strains produced pullulan. One thermotolerant non-melanin pullulan producing strain, designated as RG-5, produced highest pullulan (37.1±1.0 g/l) at 42(o)C, pH 5.5 in 48h of incubation with 3% sucrose and 0.5% ammonium sulphate in a non-stirred fed batch fermentor of 6 liters capacity. The two liters of initial volume of fermentation medium was further fed with the 2 liters in two successive batches at 5 h interval into the fermentor. The sterile air was supplied only for 10h at the rate of 0.5 vvm.

  15. Production of pullulan by a thermotolerant Aureobasidium pullulans strain in non-stirred fed batch fermentation process

    Directory of Open Access Journals (Sweden)

    Ranjan Singh

    2012-09-01

    Full Text Available Total 95 isolates of Aureobasidium pullulans were isolated from different flowers and leaves samples, out of which 11 thermotolerant strains produced pullulan. One thermotolerant non-melanin pullulan producing strain, designated as RG-5, produced highest pullulan (37.1±1.0 g/l at 42ºC, pH 5.5 in 48h of incubation with 3% sucrose and 0.5% ammonium sulphate in a non-stirred fed batch fermentor of 6 liters capacity. The two liters of initial volume of fermentation medium was further fed with the 2 liters in two successive batches at 5 h interval into the fermentor. The sterile air was supplied only for 10h at the rate of 0.5 vvm.

  16. Effects of above-optimum growth temperature and cell morphology on thermotolerance of Listeria monocytogenes cells suspended in bovine milk.

    Science.gov (United States)

    Rowan, N J; Anderson, J G

    1998-06-01

    The thermotolerances of two different cell forms of Listeria monocytogenes (serotype 4b) grown at 37 and 42.8 degrees C in commercially pasteurized and laboratory-tyndallized whole milk (WM) were investigated. Test strains, after growth at 37 or 42.8 degreesC, were suspended in WM at concentrations of approximately 1.5 x 10(8) to 3.0 x 10(8) cells/ml and were then heated at 56, 60, and 63 degrees C for various exposure times. Survival was determined by enumeration on tryptone-soya-yeast extract agar and Listeria selective agar, and D values (decimal reduction times) and Z values (numbers of degrees Celsius required to cause a 10-fold change in the D value) were calculated. Higher average recovery and higher D values (i.e., seen as a 2.5- to 3-fold increase in thermotolerance) were obtained when cells were grown at 42.8 degrees C prior to heat treatment. A relationship was observed between thermotolerance and cell morphology of L. monocytogenes. Atypical Listeria cell types (consisting predominantly of long cell chains measuring up to 60 micron in length) associated with rough (R) culture variants were shown to be 1.2-fold more thermotolerant than the typical dispersed cell form associated with normal smooth (S) cultures (P death-time (TDT) curves of R-cell forms contained a tail section in addition to the shoulder section characteristic of TDT curves of normal single to paired cells (i.e., S form). The factors shown to influence the thermoresistance of suspended Listeria cells (P pasteurization process when freely suspended and heated in WM.

  17. L-arginine, an active component of salmon milt nucleoprotein, promotes thermotolerance via Sirtuin in Caenorhabditis elegans.

    Science.gov (United States)

    Furuhashi, Tsubasa; Matsunaga, Masaji; Asahara, Yuji; Sakamoto, Kazuichi

    2016-03-25

    We previously showed that salmon milt nucleoprotein (NP) promotes thermotolerance in Caenorhabditis elegans; however, the active component and physiological mechanism of this effect has remained unclear. l-arginine (AR) is a major component of protamine and thus it has been proposed as the possible active component of NP. In this study, the viability of C. elegans treated with AR under heat stress was assessed and AR was shown to extend the survival term of the heat-stressed organisms. Additionally, AR was shown to restore the thrashing movement of the worms that is suppressed by heat stress. Treatment with AR was furthermore shown to promote thermotolerance in a DAF-16- and SIR-2.1-dependent manner, where DAF-16 and SIR-2.1 are homologs of FoxO and SirT1, respectively. Taken together, these data suggest that AR is one of the active components of NP and promotes thermotolerance via the activation of DAF-16 and SIR-2.1. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Effect of probiotic thermotolerant lactic bacteria on the physicochemical, microbiological and sensorial characteristics of cooked meat batters

    Directory of Open Access Journals (Sweden)

    Nallely Saucedo-Briviesca

    2017-07-01

    Full Text Available Some lactic acid bacteria (LAB can overexpress heat shock proteins and thus survive the heat treatment of meat products. The objective of this work was the effect of probiotic thermotolerant lactic acid bacteria on the physicochemical, microbiological and sensorial characteristics in a meat batter. Two thermotolerant probiotic lactic bacteria were used: Pediococcus pentosaceus and Enterococcus faecium, which were inoculated to 5% in a meat batter, another batter was made with the mixture of both strains; a batter without bacteria was the control. Both physicochemical and microbiological analyses were performed at day 1, 6, 13 and 16. At day 1 a discriminatory sensory evaluation was performed. The results show that the stability to cooking, expressible moisture, hardness and cohesion increased during storage in the batters inoculated with the 2 strains of LAB. The LAB increased in the inoculated meat batters and the coliforms decreased overall, when the strain mixture was used, the inhibition was total at day 6. Sensory analysis showed that judges detect when E. faecium are inoculated. Thermotolerant BALs can be used as functional ingredients in meat batters and improve physical-chemical and microbiological characteristics.

  19. The presence of opioidergic pinealocytes in the pineal gland of the European hamster (Cricetus cricetus): an immunocytochemical study

    DEFF Research Database (Denmark)

    Coto-Montes, A.; Masson-Pévet, M.; Pévet, P.

    1994-01-01

    Neurobiologi, pineal gland, leu-enkephalin, Met-enkephalin, synaptic contacts, paracrine regulation, European hamster, cricetus cricetus (rodents)......Neurobiologi, pineal gland, leu-enkephalin, Met-enkephalin, synaptic contacts, paracrine regulation, European hamster, cricetus cricetus (rodents)...

  20. Andes Virus M Genome Segment is Not Sufficient to Confer the Virulence Associated With Andres Virus in Syrian Hamsters

    National Research Council Canada - National Science Library

    McElroy, A

    2004-01-01

    ...) in North and South America, respectively. Although ANDV causes a lethal HPS-like disease in hamsters, SNV, and all other HPS-associated hantaviruses that have been tested, cause asymptomatic infections of laboratory animals, including hamsters...

  1. Transplantation of hamster lung lesions induced by 239PuO2 or benz(a)pyrene

    International Nuclear Information System (INIS)

    McDonald, K.E.; Sanders, C.L.

    1980-01-01

    None(0%) of 1000 recipients of lung lesions for 239 PuO 2 -exposed hamsters that were transplanted into other hamsters' cheek pouches, developed tumors, whereas 90% of transplants from benz(a)pyrene-induced lung lesions were malignant

  2. Effect of prenatal and postnatal photoperiod on spermatogenic development in the Djungarian hamster (Phodopus sungorus sungorus)

    NARCIS (Netherlands)

    van Haaster, L. H.; van Eerdenburg, F. J.; de rooij, D. G.

    1993-01-01

    The effect of the pre- and postnatal daylength on the start of spermatogenesis and further testicular development from day 4 up to day 127 was investigated in Djungarian hamsters. Hamsters were either gestated under long (16 h light:8 h dark) photoperiod and reared under long or short (4 h light:20

  3. [The annual cycle in the Djungarian Hamster Phodopus sungorus Pallas].

    Science.gov (United States)

    Figala, J; Hoffmann, K; Goldau, G

    1973-06-01

    Seasonal variations in several functions were observed in a strain of Phodopus s. sungorus bred and kept in the laboratory at Erling-Andechs (47° 58'N, 11° 11'E) under natural illumination: 1. During their first winter most hamsters changed into a whitish winter coat (Figs. 2, 5, and 14). The change in fur coloration is described (Fig. 1). In most animals molt into the winter coat started in October or November, and was completed in December. Molt into the summer coat started in January or February, and was completed in March or early April. Hamsters kept at outdoor temperatures started molt into winter pelt earlier, and finished molt into summer pelt later, than animals kept indoors (Figs. 3 and 4). Winter coloration was more extreme in animals kept at outdoor temperatures. 2. Molt into the winter coat was induced in summer by exposing hamsters to short photoperiods (Fig. 6). However, these animals spontaneously changed back into summer fur while remaining under short-day conditions. 3. The animals had a marked annual cycle in body weight with maximum weight in July and August, and minimum weight in December and January, while they were in winter pelage (Figs. 7 and 8). 4. Reproduction was observed only between February and November (Fig. 9). Young were born within 18 days (2 cases) or 19 days (27 cases) after the breeding pairs were established. Mean litter size was 5 (range 1-9) (Fig. 10). Average litter size was smaller in the first litter of a ♀ than in the second, but was smaller again in subsequent litters (Fig. 11). 5. Growth curves of young hamsters were compared with data from the literature (Fig. 12). In the mean ♂ ♂ were heavier than ♀ ♀ (Table 1). 6. The majority of ♂ ♂ showed testis involution during the first winter. The weight of winter testes was about 1/9th that of summer testes (Fig. 13). The cauda epididymidis contained no spermatozoa in winter animals, and many in summer animals. 7. Daily torpor was observed in many animals, but

  4. Effect of deuterium on the circadian period and metabolism in wild-type and tau mutant Syrian hamsters

    NARCIS (Netherlands)

    Oklejewicz, M; Hut, RA; Daan, S

    2000-01-01

    Homozygous tau mutant Syrian hamsters (tau-/-) have a free-running circadian period (tau) around 20 h and a proportionally higher metabolic rate compared with wild-type hamsters (tau+/+) with a period of circa 24 h. In this study, we applied deuterium oxide (D2O) to hamsters to test whether

  5. Transcriptome analysis of the thermotolerant yeast Kluyveromyces marxianus CCT 7735 under ethanol stress.

    Science.gov (United States)

    Diniz, Raphael Hermano Santos; Villada, Juan C; Alvim, Mariana Caroline Tocantins; Vidigal, Pedro Marcus Pereira; Vieira, Nívea Moreira; Lamas-Maceiras, Mónica; Cerdán, María Esperanza; González-Siso, María-Isabel; Lahtvee, Petri-Jaan; da Silveira, Wendel Batista

    2017-09-01

    The thermotolerant yeast Kluyveromyces marxianus displays a potential to be used for ethanol production from both whey and lignocellulosic biomass at elevated temperatures, which is highly alluring to reduce the cost of the bioprocess. Nevertheless, contrary to Saccharomyces cerevisiae, K. marxianus cannot tolerate high ethanol concentrations. We report the transcriptional profile alterations in K. marxianus under ethanol stress in order to gain insights about mechanisms involved with ethanol response. Time-dependent changes have been characterized under the exposure of 6% ethanol and compared with the unstressed cells prior to the ethanol addition. Our results reveal that the metabolic flow through the central metabolic pathways is impaired under the applied ethanol stress. Consistent with these results, we also observe that genes involved with ribosome biogenesis are downregulated and gene-encoding heat shock proteins are upregulated. Remarkably, the expression of some gene-encoding enzymes related to unsaturated fatty acid and ergosterol biosynthesis decreases upon ethanol exposure, and free fatty acid and ergosterol measurements demonstrate that their content in K. marxianus does not change under this stress. These results are in contrast to the increase previously reported with S. cerevisiae subjected to ethanol stress and suggest that the restructuration of K. marxianus membrane composition differs in the two yeasts which gives important clues to understand the low ethanol tolerance of K. marxianus compared to S. cerevisiae.

  6. Isolation, Production, and Characterization of Thermotolerant Xylanase from Solvent Tolerant Bacillus vallismortis RSPP-15

    Directory of Open Access Journals (Sweden)

    Rajeeva Gaur

    2015-01-01

    Full Text Available Sixty bacterial strains isolated from the soils sample in the presence of organic solvent were screened for xylanase production. Among them, strain RSPP-15 showed the highest xylanase activity which was identified as Bacillus vallismortis. The isolate showed maximum xylanase production (3768 U/mL in the presence of birch wood xylan and beef extract at 55°C pH 7.0 within 48 h of incubation. The enzyme activity and stability were increased 181.5, 153.7, 147.2, 133.6, and 127.9% and 138.2, 119.3, 113.9, 109, and 104.5% in the presence of Co2+, Ca2+, Mg+2, Zn+2, and Fe+3 ions (10 mM. Xylanase activity and stability were strongly inhibited in the presence of Hg and Cu ions. The enzyme was also stable in the presence of 30% of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the xylanase stability, respectively. This isolate may be useful in several industrial applications owing to its thermotolerant and organic solvent resistance characteristics.

  7. ISOLATION AND IDENTIFICATION OF A THERMOTOLERANT PLANT GROWTH PROMOTING PSEUDOMONAS PUTIDA PRODUCING TREHALOSE SYNTHASE

    Directory of Open Access Journals (Sweden)

    Ali Sk.Z.

    2013-08-01

    Full Text Available A thermotolerant plant growth promoting Pseudomonas isolate growing at 40oC producing trehalose synthase (TreS was isolated from rhizosphere soil under semi arid conditions of India. Trehalose synthase was extracted; purified and enzymatic activity was examined at various temperatures and pH. The optimum temperature and pH was 38oC and pH 7.5 and the activity declined at above or below the optimum pH and temperature. The enzyme was active on maltose and trehalose among saccharides tested. The enzyme had a higher catalytic activity for maltose with a trehalose yield of 72% than for trehalose where 30% yield of maltose was achieved, indicating maltose as preferred substrate. The isolate showed multiple plant growth promoting traits (indole acetic acid (IAA, phosphate solubilization, siderophore and ammonia both at ambient (28oC and high temperature (40oC. Based on phenotypic and 16SrRNA analysis the isolate was identified as Pseudomonas putida (Accession No. GU396283.

  8. Purification and Characterization of Organic Solvent and Detergent Tolerant Lipase from Thermotolerant Bacillus sp. RN2

    Directory of Open Access Journals (Sweden)

    Tadahiko Kajiwara

    2010-09-01

    Full Text Available The aim of this study was to characterize the organic solvent and detergent tolerant properties of recombinant lipase isolated from thermotolerant Bacillus sp. RN2 (Lip-SBRN2. The isolation of the lipase-coding gene was achieved by the use of inverse and direct PCR. The complete DNA sequencing of the gene revealed that the lip-SBRN2 gene contains 576 nucleotides which corresponded to 192 deduced amino acids. The purified enzyme was homogeneous with the estimated molecular mass of 19 kDa as determined by SDS-PAGE and gel filtration. The Lip-SBRN2 was stable in a pH range of 9–11 and temperature range of 45–60 °C. The enzyme was a non metallo-monomeric protein and was active against pNP-caprylate (C8 and pNP-laurate (C12 and coconut oil. The Lip-SBRN2 exhibited a high level of activity in the presence of 108% benzene, 102.4% diethylether and 112% SDS. It is anticipated that the organic solvent and detergent tolerant enzyme secreted by Bacillus sp. RN2 will be applicable as catalysts for reaction in the presence of organic solvents and detergents.

  9. Occurrence of Thermotolerant Hartmannella Vermiformis and Naegleria Spp. in Hot Springs of Ardebil Province, Northwest Iran

    Directory of Open Access Journals (Sweden)

    E Nazemalhosseini Mojarad

    2012-06-01

    Full Text Available Background: Geothermal waters could be suitable niches for thermophilic free living amoebae including Naegleria and Hartmannella. Ardebil Province, northwest Iran is popular for having many hot springs for recreational and health purposes activity. The present research is the first molecular based investigation regarding the presence of Naegleria and Hartmannella in the hot springs of Ardebil Province in Iran.Methods: Overall, 30 water samples were taken from waters of thermal hot springs in Ardebil Province, Iran during 2010-2011. All collected samples were transferred to Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Cultivation of concentrated water samples was performed using culture-enrichment method. Cloning of the target amoebae was obtained and morphological and molecular analysis was done using page key combined with two sets of primers, respectively. Sequence analysis and homology search was used for strains identification.Results: Of 30 water samples, 8 (26.7% were positive for thermotolerant Vahlkampfiids and Hartman­nella based on morphological characteristics of vegetative form and double walled cysts. Cloning of the target amoebae were done successfully. Sequencing of the positive isolates revealed that the strains belonged to Naegleria (N. carteri and N. spp and H. vermiformis.Conclusion: The result highlights a need for improved filtration and disinfection and periodic monitoring of recreational thermal waters in order to prevent disease related to free- living amoebae. This is the first comprehensive molecular study of thermophilic Naegleria and Hartmannella in hot springs of Iran.

  10. Occurrence of Thermotolerant Hartmannella vermiformis and Naegleria Spp. in Hot Springs of Ardebil Province, Northwest Iran.

    Science.gov (United States)

    Solgi, R; Niyyati, M; Haghighi, A; Mojarad, E Nazemalhosseini

    2012-01-01

    Geothermal waters could be suitable niches for thermophilic free living amoebae including Naegleria and Hartmannella. Ardebil Province, northwest Iran is popular for having many hot springs for recreational and health purposes activity. The present research is the first molecular based investigation regarding the presence of Naegleria and Hartmannella in the hot springs of Ardebil Province in Iran. Overall, 30 water samples were taken from waters of thermal hot springs in Ardebil Province, Iran during 2010-2011. All collected samples were transferred to Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Cultivation of concentrated water samples was performed using culture-enrichment method. Cloning of the target amoebae was obtained and morphological and molecular analysis was done using page key combined with two sets of primers, respectively. Sequence analysis and homology search was used for strains identification. Of 30 water samples, 8 (26.7%) were positive for thermotolerant Vahlkampfiids and Hartmannella based on morphological characteristics of vegetative form and double walled cysts. Cloning of the target amoebae were done successfully. Sequencing of the positive isolates revealed that the strains belonged to Naegleria (N. carteri and N. spp) and H. vermiformis. The result highlights a need for improved filtration and disinfection and periodic monitoring of recreational thermal waters in order to prevent disease related to free- living amoebae. This is the first comprehensive molecular study of thermophilic Naegleria and Hartmannella in hot springs of Iran.

  11. Bioconversion of Airborne Methylamine by Immobilized Recombinant Amine Oxidase from the Thermotolerant Yeast Hansenula polymorpha

    Directory of Open Access Journals (Sweden)

    Sasi Sigawi

    2014-01-01

    Full Text Available Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health. The primary amine oxidase (primary amine : oxygen oxidoreductase (deaminating or amine oxidase, AMO; EC 1.4.3.21, a copper-containing enzyme from the thermotolerant yeast Hansenula polymorpha which was overexpressed in baker’s yeast Saccharomyces cerevisiae, was tested for its ability to oxidize airborne methylamine. A continuous fluidized bed bioreactor (CFBR was designed to enable bioconversion of airborne methylamine by AMO immobilized in calcium alginate (CA beads. The results demonstrated that the bioreactor with immobilized AMO eliminates nearly 97% of the airborne methylamine. However, the enzymatic activity of AMO causes formation of formaldehyde. A two-step bioconversion process was therefore proposed. In the first step, airborne methylamine was fed into a CFBR which contained immobilized AMO. In the second step, the gas flow was passed through another CFBR, with alcohol oxidase from the yeast H. polymorpha immobilized in CA, in order to decompose the formaldehyde formed in the first step. The proposed system provided almost total elimination of the airborne methylamine and the formaldehyde.

  12. Determination of thermotolerant coliforms present in coconut water produced and bottled in the Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Vandbergue Santos Pereira

    2017-10-01

    Full Text Available Abstract Coconut water is considered to be a natural isotonic drink and its marketing is gradually increasing. The objective of the present study was to evaluate the microbiological quality of the coconut water produced and bottled in the Northeast of Brazil. Products form ten industries from different states in the Northeast of Brazil were analyzed. The most probable number (MPN method was used to quantify the coliforms. Samples showing positive for coliforms were seeded on ChromAgar Orient plates and the bacteria identified from isolated colonies using the automated system Vitek 2 (BioMérieux, according to the manufacturer's instructions for the preparation of the inoculum, incubation, reading and interpretation. The samples showed thermotolerant coliform counts between 6.0×102 and 2.6×104 MPN/100 mL. The presence of Klebsiella pneumoniae, Morganella morganii and Providencia alcalifaciens was observed. The implementation of preventive methods and monitoring of the water quality by the industries is required.

  13. Whole genome detection of signature of positive selection in African cattle reveals selection for thermotolerance.

    Science.gov (United States)

    Taye, Mengistie; Lee, Wonseok; Caetano-Anolles, Kelsey; Dessie, Tadelle; Hanotte, Olivier; Mwai, Okeyo Ally; Kemp, Stephen; Cho, Seoae; Oh, Sung Jong; Lee, Hak-Kyo; Kim, Heebal

    2017-12-01

    As African indigenous cattle evolved in a hot tropical climate, they have developed an inherent thermotolerance; survival mechanisms include a light-colored and shiny coat, increased sweating, and cellular and molecular mechanisms to cope with high environmental temperature. Here, we report the positive selection signature of genes in African cattle breeds which contribute for their heat tolerance mechanisms. We compared the genomes of five indigenous African cattle breeds with the genomes of four commercial cattle breeds using cross-population composite likelihood ratio (XP-CLR) and cross-population extended haplotype homozygosity (XP-EHH) statistical methods. We identified 296 (XP-EHH) and 327 (XP-CLR) positively selected genes. Gene ontology analysis resulted in 41 biological process terms and six Kyoto Encyclopedia of Genes and Genomes pathways. Several genes and pathways were found to be involved in oxidative stress response, osmotic stress response, heat shock response, hair and skin properties, sweat gland development and sweating, feed intake and metabolism, and reproduction functions. The genes and pathways identified directly or indirectly contribute to the superior heat tolerance mechanisms in African cattle populations. The result will improve our understanding of the biological mechanisms of heat tolerance in African cattle breeds and opens an avenue for further study. © 2017 Japanese Society of Animal Science.

  14. Thermophillic and thermotolerant fungi isolated from the thermal effluent of nuclear power generating reactors

    International Nuclear Information System (INIS)

    Rippon, J.W.; Gerhold, R.; Heath, M.

    1980-01-01

    Over a period of a year, samples of water, foam, microbial mat, soil and air were obtained from areas associated with the cooling canal of a nuclear power station. The seventeen sample sites included water in the cooling canal that was thermally enriched and soil and water adjacent to, up-stream, downstream and at a distance from the generator. Air samples were taken at the plant and at various disstances from the plant. Fifty-two species of thermotolerant and thermophilic fungi were isolated. Of these, eleven species are grouped as opportunistic Mucorales or opportunistic Aspergillus sp. One veterinary pathogen was also isolated (Dactylaria gallopara). The opportunistic/pathogenic fungi were found primarily in the intake bay, the discharge bay and the cooling canal. Smaller numbers were obtained at both upstream and downstream locations. Soil samples near the cooling canal reflected an enrichment of thermophilous organisms, the previously mentioned opportunistic Mucorales and Aspergillus spp. Their numbers were found to be greater than that usually encountered in a mesophilic environment. However, air and soil samples taken at various distances from the power station indicated no greater abundance of these thermophilous fungi than would be expected from a thermal enriched environment. Our results indicate that there was no significant dissemination of thermophilous fungi from the thermal enriched effluents to the adjacent environment. These findings are consistent with the results of other investigators. (orig.)

  15. Differentiation of hamster liver oval cell following Clonorchis sinensis infection.

    Science.gov (United States)

    Yoon, B I; Jung, S Y; Hur, K; Lee, J H; Joo, K H; Lee, Y S; Kim, D Y

    2000-12-01

    Oval cells which appear in the liver after hepatic injuries are suspected to be progenitor cells for both hepatocytes and bile duct cells. Oval cell isolated from the livers of the hamsters treated with diethylnitrosamine and 2-acetylaminofluorene and infected with Clonorchis sinensis (CS). cultured for 2 weeks and evaluated for differentiation and plasticity by electron microscopy and immunohistochemistry. In the CS-uninfected group, glycogen granules and peroxisomes were noted in the cells that were cultured for 2 weeks. Starting at 1 week postculture, immunoreactivity of the cells to cytokeratin 19 markedly decreased but that to albumin and alpha-fetoprotein gradually increased. This means that oval cells isolated from hamsters that were not infected with CS differentiated toward hepatocyte lineage. However, in the CS-infected group, cultured cells contained numerous rough endoplasmic reticulum and showed immunoreactivity that was generally in reverse to that of CS-uninfected group, meaning that cells isolated following CS infection were primed by CS and differentiated toward bile duct cell lineage. The results of this study suggested that oval cells are indeed bipolar progenitor cells for hepatocytes and bile duct cells and can differentiate toward either lineage depending upon the priming factor.

  16. Expression of thioredoxin during progression of hamster and human cholangiocarcinoma.

    Science.gov (United States)

    Yoon, Byung-Il; Kim, Yeong-Hun; Yi, Jung-Yeon; Kang, Min-Soo; Jang, Ja-June; Joo, Kyoung-Hwan; Kim, Yongbaek; McHugh Law, J; Kim, Dae-Yong

    2010-01-01

    Thioredoxin (Trx) is a multifunctional redox protein that has growth-promoting and anti-apoptotic effects on cells and protects cells from endogenous and exogenous free radicals. Recently, altered expression of Trx has been reported in various cancers. In the present study, we investigated altered expression of Trx at the precancerous and carcinogenic phases during cholangiocarcinogenesis in a hamster cholangiocarcinoma (ChC) model, using semiquantitative immunohistochemical and Western blot analyses. Moreover, to determine if the results correlated well with those in human ChCs, we carried out a comparative immunohistochemical study for Trx in tissue-arrayed human ChCs with different grades of tumor cell differentiation. Trx was found highly expressed in the cytoplasm of dysplastic bile ducts with highly abnormal growth patterns and ChCs irrespective of tumor type or tumor cell differentiation. Overexpression of Trx at the precancerous and carcinogenic phases was further supported by significant elevation of Trx protein in Western blotting. The results from the hamster ChCs were in good agreement with those from human ChCs. Our results strongly suggested that the redox regulatory function of Trx plays an important role in bile duct cell transformation and tumor progression during cholangiocarcinogenesis.

  17. Role of luteinizing hormone in luteotropic complex of pregnant hamster

    International Nuclear Information System (INIS)

    Tamura, H.; Greenwald, G.S.

    1987-01-01

    Hamsters were hypophysectomized on day 4 of pregnancy and injected subcutaneously on days 4-7 with various combinations of 200 μg prolactin (Prl), 10 μg follicle-stimulating hormone (FSH), and 20 μg luteinizing hormone (LH) in polyvinylpyrrolidone (PVP) to decrease its rate of absorption or in saline. End points for luteal function on day 8 were maintenance of pregnancy, serum progesterone (P 4 ), luteal weight, and luteal binding for human chorionic gonadotropin, FSH, and Prl. After hypophysectomy, a drastic decline occurred in all parameters including an 89% decrease in luteal weight. Injection of Prl did not maintain pregnancy nor serum P 4 but partially maintained luteal weight and human chorionic gonadotropin binding sites per corpus luteum. The minimal luteotropic complex of Prl and FSH was effective in maintaining pregnancy and significantly increased serum P 4 and Prl and FSH receptors but not to control levels. Thus, the luteotropic activity of LH was only demonstrable when it was injected in a long-acting form; when delivered as a bolus, LH (saline) was luteolytic. P 4 and estradiol were measured by radioimmunoassay. Radioiodinated gonadotropins were prepared. The percentage of tracer reacting with an excess of receptor were 51% of 125 I-FSH and 45.9% of 125 I-hCG using whole homogenates of hamster ovaries

  18. Determination of elements in blood of golden hamster by NAA

    International Nuclear Information System (INIS)

    Aguiar, Rodrigo Oliveira de

    2009-01-01

    In the present study Neutron Activation Analysis technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of golden hamster. The normal range for Br, Ca, Cl K, Mg, Na and S considering 2 σ (Two Standard deviations) was 0.011 0.047 gL -1 (Br); 0.11 0.35 gL -1 (Ca); 2.11 3.75 gL -1 (Cl); 1.35 2.79 gL -1 (K), 0.026 0.090 gL -1 (Mg), 1.03 2.51 gL -1 (Na) e 0.97 2.01 gL -1 (S). The knowledge of these limits became possible to perform clinical investigation in this animal model using whole blood. The comparison with the results from human being whole blood estimation (Hamster and human) became possible to check the similarities or physiologic differences, an important data for animal experimentation. (author)

  19. Chinese hamster ovary (CHO-K1) cells expressed native insulin-like ...

    African Journals Online (AJOL)

    These are two characteristics of mammalian cell culture which may lead to high density cell culture producing optimal desired yield of bioproducts. An inherent secretion of IGF-1 protein from host cells into the culture media is hypothesized to enable reduction or removable of serum from culture media, thus reducing cost.

  20. X-ray-sensitive mutants of Chinese hamster ovary cell line

    International Nuclear Information System (INIS)

    Jeggo, P.A.; Kemp, L.M.

    1983-01-01

    A standard technique of microbial genetics, which involves the transfer of cells from single colonies by means of sterile toothpicks, has been adapted to somatic cell genetics. Its use has been demonstrated in the isolation of X-ray-sensitive mutants of CHO cells. 9000 colonies have been tested and 6 appreciably X-ray-sensitive mutants were isolated. (D 10 values 5-10-fold of wild-type D 10 value.) A further 6 mutants were obtained which showed a slight level of sensitivity (D 10 values less than 2-fold of wild-type D 10 value). The 6 more sensitive mutants were also sensitive to bleomycin, a chemotherapeutic agent inducing X-ray-like damage. Cross-sensitivity to UV-irradiation and treatment with the alkylating agents, MMS, EMS and MNNG, was investigated for these mutants. Some sensitivity to these other agents was observed, but in all cases it was less severe than the level of sensitivity to X-irradiation. Each mutant showed a different overall response to the spectrum of agents examined and these appear to represent new mutant phenotypes derived from cultured mammalian cell lines. One mutant strain, xrs-7, was cross-sensitive to all the DNA-damaging agents, but was proficient in the repair of single-strand breaks. (Auth.)

  1. Chromosome damage in Chinese hamster cells sensitized to near-ultraviolet light by psoralen and angelicin

    International Nuclear Information System (INIS)

    The clastogenic effect of furocoumarins psoralen and angelicin in the presence of near-UV (320-380 nm) differs greatly, as do their modes of interaction with DNA. Psoralen, which requires only one-fifth as much light energy to produce the same lethal effect as angelicin at equimolar concentrations, is able to cross-link DNA whereas angelicin cannot. The frequency of micronuclei which arise from chromosomal fragments shows the same differential effect as lethality. Indeed aberrations account for much or all of the lethality observed. Metaphase analysis at comparable aberration frequencies revealed that angelicin and psoralen both induce chromatid deletions and a wide spectrum of chromatid exchanges. These data show that both cross-links and monoadducts to the DNA can result in chromosomal aberrations. The relative contributions of cross-links and monoadducts to chromosomal aberrations still remain to be determined. It is noteworthy that extensive chromosomal damage is induced in mammalian cells by the combination of psoralen and near-UV, a treatment which is currently widely used in the therapy of psoriasis

  2. Segmentation and Quantitative Analysis of Apoptosis of Chinese Hamster Ovary Cells from Fluorescence Microscopy Images.

    Science.gov (United States)

    Du, Yuncheng; Budman, Hector M; Duever, Thomas A

    2017-06-01

    Accurate and fast quantitative analysis of living cells from fluorescence microscopy images is useful for evaluating experimental outcomes and cell culture protocols. An algorithm is developed in this work to automatically segment and distinguish apoptotic cells from normal cells. The algorithm involves three steps consisting of two segmentation steps and a classification step. The segmentation steps are: (i) a coarse segmentation, combining a range filter with a marching square method, is used as a prefiltering step to provide the approximate positions of cells within a two-dimensional matrix used to store cells' images and the count of the number of cells for a given image; and (ii) a fine segmentation step using the Active Contours Without Edges method is applied to the boundaries of cells identified in the coarse segmentation step. Although this basic two-step approach provides accurate edges when the cells in a given image are sparsely distributed, the occurrence of clusters of cells in high cell density samples requires further processing. Hence, a novel algorithm for clusters is developed to identify the edges of cells within clusters and to approximate their morphological features. Based on the segmentation results, a support vector machine classifier that uses three morphological features: the mean value of pixel intensities in the cellular regions, the variance of pixel intensities in the vicinity of cell boundaries, and the lengths of the boundaries, is developed for distinguishing apoptotic cells from normal cells. The algorithm is shown to be efficient in terms of computational time, quantitative analysis, and differentiation accuracy, as compared with the use of the active contours method without the proposed preliminary coarse segmentation step.

  3. Sister Chromatid Exchange Assay of Nitroguanidine in Chinese Hamster Ovary Cells

    Science.gov (United States)

    1988-07-01

    W. HarbellI , >LAJ, MSC; LilIi ic 1). Witcher , SGT, USA; Don W. Korte, Jr.,1- -NE 1;7 PEPORT 󈧑b TIME COiVERED 1 ATE OF REPORT (Year, Month, Day) 15...Investigator LIILIf- D WITCHER , i /_ Dat- SGT, U-A CC.iKBA2 R. WHEELER, PhD / Date DAC Analytical Chemist v •N DEPARTMENT OF THE ARMY LETTERMIAN ARMY...carcinogens. M.tat Res 1977; 48: 337-354. 7. Harbell JW, Witcher LD, Sebastian SE, Korte DW. Studies on the mutagenic potential of nitrocuanidine and

  4. Chinese hamster ovary (CHO-K1) cells expressed native insulin-like ...

    African Journals Online (AJOL)

    GREGORY

    2011-12-16

    Dec 16, 2011 ... be particularly useful for further studies using CHO-K1 cells as efficient mammalian cell culture host system to produce biologics. ... CO2/37°C. T-75 flasks (Orange Scientific, Belgium) were used for cell cultivation. All cultures were initiated at seeding concentration of. 20 x 104 cells/ml and experiments were ...

  5. Interactions of adriamycin and X-rays in Chinese hamster cells

    International Nuclear Information System (INIS)

    Meder, G.

    1982-01-01

    The effect of a combined ADM-and-radiation treatment of varying intervals was investigated in vitro. ADM sensitized the cells for the subsequent irradiation. This action was noticeable after 7h as a synergystic and after 2 and 3d as an additive effect of the combination treatment. Obviously, the ADM damage was inherited by the following cell generations. After 7d the sensitization of the cells could no longer be proved. From these results and those of other authors some general conclusions can be drawn. Different cell types react differently to the same kind of treatment. All forms of interaction are noticeable. Moreover, the ADM damage is obviously inherited. It must be assumed that this variability of the phenomena observed in vitro is also found in the human organism. (orig.) [de

  6. Size and number of DNA molecules from Chinese hamster ovary cells determined by molecular autoradiography

    International Nuclear Information System (INIS)

    Todd, M.B.

    1980-06-01

    A new method for visualization of separable subunits of DNA is described. Autoradiography of tritium-labeled DNA from one or a few nuclei, lysed with detergent, moderate salt, and proteases, and gently deposited on a filter, allows determination of subunit molecular weight, size distribution, number per nucleus, and organization. The shape of the size distribution of CHO subunit images is similar to that of CHO mitotic chromosomes, and the numbers of subunits per nucleus supports a model of eight subunits per chromosome

  7. Induction of HPRT- mutants in Chinese hamster V79 cells after heavy ion exposure

    International Nuclear Information System (INIS)

    Stoll, U.; Schneider, E.; Kranert, T.; Kiefer, J.

    1995-01-01

    The induction of resistance to 6-thioguanine by heavy ion exposure was investigated with various accelerated ions (oxygen-uranium) up to linear energy transfer (LET) values of about 15 000 keV/μm. Survival curves are exponential with fluence; mutation induction shows a linear dependence. Cross-sections (σ i : inactivation, σ m : mutation) were derived from the respective slopes. Generally, σ i rises over the whole LET range, but separates into different declining curves for single ions with LET values above 200 keV/μm. Similar behaviour is seen for σ m . The new SIS facility at GSI, Darmstadt, makes it possible to study the effects of ions with the same LET but very different energies and track structures. Experiments using nickel and oxygen ions (up to 400 MeV/u) showed that inactivation cross-sections do not depend very much on track structure, i.e. similar values are found with different ions at the same LET. This is not the case for mutation induction, where very energetic ions display considerably smaller induction cross-sections compared with low-energy ions of identical LET. Preliminary analyses using the polymerase chain reaction (PCR) demonstrate that even heavy ions cause ''small alterations'' (small deletions or base changes). The proportion of the total deletions seems to increase with LET. (orig.)

  8. Acceptors for poly(ADP-ribose) in irradiated Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Xue, L.Y.; Sokany, N.M.; Friedman, L.R.; Oleinick, N.L.

    1985-01-01

    Strand breaks in DNA, as produced by ionizing radiation, stimulate the synthesis of poly(ADP-ribose) (pADPR) by the nuclear enzyme pADPR transferase (ADPRT). The polymer is covalently bound to chromatin-associated proteins and may function in repair of DNA lesions. When total /sup 32/P-pADPR-protein is analyzed by electrophoresis on SDS-polyacrylamide gels, the major radioactive bands correspond to the 116 kD ADPRT and the low molecular weight (histone) region. On two-dimensional gels (isoelectric focusing followed by SDS-PAGE) several ADP-ribosylated species can be detected in each molecular weight range. The intensity of label in each species is greater for proteins isolated from irradiated (10 or 100 Cy) rather than control cells. For detailed analysis of histones, the authors incubated isolated nuclei with /sup 32/P-NAD, extracted histones in acid, and subjected them to electrophoresis in acid-urea gels. Specific radiation-induced increases in pADPR were seen on some nucleosomal core histone bands but not on histone H1. The results suggest that radiation-induced strand breaks stimulate ADPRT to modify core histones; the resultant increase in negative charge could loosen nucleosomal structure, permitting access of repair enzymes to the DNA lesions

  9. Matrix attachment region combinations increase transgene expression in transfected Chinese hamster ovary cells

    OpenAIRE

    Chun-Peng Zhao; Xiao Guo; Si-Jia Chen; Chang-Zheng Li; Yun Yang; Jun-He Zhang; Shao-Nan Chen; Yan-Long Jia; Tian-Yun Wang

    2017-01-01

    Matrix attachment regions (MARs) are cis-acting DNA elements that can increase transgene expression levels in a CHO cell expression system. To investigate the effects of MAR combinations on transgene expression and the underlying regulatory mechanisms, we generated constructs in which the enhanced green fluorescent protein (eGFP) gene flanked by different combinations of human ?-interferon and ?-globin MAR (iMAR and gMAR, respectively), which was driven by the cytomegalovirus (CMV) or simian ...

  10. Purine biosynthesis in Chinese Hamster cell mutants and human fibroblasts partially deficient in adenylosuccinate lyase

    International Nuclear Information System (INIS)

    Laikind, P.K.; Gruber, H.E.; Hoffer, M.; Jansen, I.; Miller, L.; Seegmiller, J.E.

    1986-01-01

    In a study of purine nucleotide metabolism of CHO-Ade I cells and fibroblasts from an adenylocsuccinate (AS) and SAICA riboside over-producing pattient the authors examined the effect of ASMP lyase deficiency on brachpoint enzyme activities and on de novo synthesis by comparison to the control cell lines, wild type parent cells (CHO-K1) and fibroblasts from age-matched normal individuals, respectively. The rate of newly-formed purine synthesis and excretion was measured by determining the amount of C 14-formate incorporatted into adenine, hypoxanthine, and guanasine moities. The nucleotide, nucleoside and base content of cells and media were analyzed by hhigh-pressure liquid chrromatography. Results are presented

  11. Role of repair saturation in the response of plateau-phase Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Braby, L.A.; Nelson, J.M.; Metting, N.F.

    1987-01-01

    Two repair rates are seen in split-dose experiments on starved plateau-phase CHO cells. It has been assumed that this indicates two different processes repairing two distinct types of sublethal damage. However results of experiments at different dose levels are not consistent with models that assume that the damage is entirely sublethal. Another hypothesis that has been considered is the saturation of a repair mechanism having a limited pool of repair enzymes. Such saturation phenomena have been observed in biochemical repair studies and have thus formed the basis for a model of cellular response, which was shown to be capable of producing dose response curves in good agreement with experimental observations. This model can be extended to account for both dose-rate and split-dose effects

  12. Generation of a Chinese Hamster Ovary Cell Line Producing Recombinant Human Glucocerebrosidase

    Science.gov (United States)

    Novo, Juliana Branco; Morganti, Ligia; Moro, Ana Maria; Paes Leme, Adriana Franco; Serrano, Solange Maria de Toledo; Raw, Isaias; Ho, Paulo Lee

    2012-01-01

    Impaired activity of the lysosomal enzyme glucocerebrosidase (GCR) results in the inherited metabolic disorder known as Gaucher disease. Current treatment consists of enzyme replacement therapy by administration of exogenous GCR. Although effective, it is exceptionally expensive, and patients worldwide have a limited access to this medicine. In Brazil, the public healthcare system provides the drug free of charge for all Gaucher's patients, which reaches the order of $ 84 million per year. However, the production of GCR by public institutions in Brazil would reduce significantly the therapy costs. Here, we describe a robust protocol for the generation of a cell line producing recombinant human GCR. The protein was expressed in CHO-DXB11 (dhfr−) cells after stable transfection and gene amplification with methotrexate. As expected, glycosylated GCR was detected by immunoblotting assay both as cell-associated (~64 and 59 kDa) and secreted (63–69 kDa) form. Analysis of subclones allowed the selection of stable CHO cells producing a secreted functional enzyme, with a calculated productivity of 5.14 pg/cell/day for the highest producer. Although being laborious, traditional methods of screening high-producing recombinant cells may represent a valuable alternative to generate expensive biopharmaceuticals in countries with limited resources. PMID:23091360

  13. Generation of a Chinese Hamster Ovary Cell Line Producing Recombinant Human Glucocerebrosidase

    Directory of Open Access Journals (Sweden)

    Juliana Branco Novo

    2012-01-01

    Full Text Available Impaired activity of the lysosomal enzyme glucocerebrosidase (GCR results in the inherited metabolic disorder known as Gaucher disease. Current treatment consists of enzyme replacement therapy by administration of exogenous GCR. Although effective, it is exceptionally expensive, and patients worldwide have a limited access to this medicine. In Brazil, the public healthcare system provides the drug free of charge for all Gaucher’s patients, which reaches the order of $ 84 million per year. However, the production of GCR by public institutions in Brazil would reduce significantly the therapy costs. Here, we describe a robust protocol for the generation of a cell line producing recombinant human GCR. The protein was expressed in CHO-DXB11 (dhfr− cells after stable transfection and gene amplification with methotrexate. As expected, glycosylated GCR was detected by immunoblotting assay both as cell-associated (~64 and 59 kDa and secreted (63–69 kDa form. Analysis of subclones allowed the selection of stable CHO cells producing a secreted functional enzyme, with a calculated productivity of 5.14 pg/cell/day for the highest producer. Although being laborious, traditional methods of screening high-producing recombinant cells may represent a valuable alternative to generate expensive biopharmaceuticals in countries with limited resources.

  14. DNA replication in Chinese hamster ovary cells made permeable to nucleotides by Tween-80 treatment

    Energy Technology Data Exchange (ETDEWEB)

    Billen, D.; Olson, A.C.

    1976-01-01

    We have developed a method for permeabilizing CHO cells to nucleotides under conditions which allow most cells to remain viable. Permeabilized cells can carry out ATP-dependent, semiconservative synthesis of DNA. The data are consistent with the continuation of DNA synthesis in those cells in S phase at the time of treatment, possibly limited to completion of replicon synthesis without new initiations.

  15. Excision of UV-induced pyrimidine dimers from DNA of Chinese hamster CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Barenfel' d, L.S.; Bikhanskaya, F.L. (AN SSSR, Leningrad. Inst. Tsitologii)

    1983-10-01

    The sedimentation method in alkali gradients of saccharose when using UV-endonuclease from Micrococcus lutenius has been applied to investigate cleavage of UV-induced pyrimidine dimers from DNA cells (CHO). It is shown that essential part of pyrimidine dimers (approximately 80%) are cleaved during 26 h of postradiation incubation while during the first 17 h after UV-radiation (4J/m/sup 2/) reparation proceeds negligibly (approximately 15%).

  16. Changes of spontaneous parthenogenetic activation and development potential of golden hamster oocytes during the aging process.

    Science.gov (United States)

    Jiang, Han; Wang, Ce; Guan, Jiyu; Wang, Lingyan; Li, Ziyi

    2015-01-01

    The golden hamster is an excellent animal experimental model for oocyte research. The hamster oocytes are very useful in clinical examination of human spermatozoan activity. Non-fertile oocytes can lead to time-dependent processes of aging, which will affect the results of human spermatozoa examination. As a consequence there is a need to investigate the aging and anti-aging processes of golden hamster oocytes. In order to study the aging processes and parthenogenetic activation of golden hamster oocytes, in vivo oocytes, oocytes cultured with or without cumulus cells, and oocytes treated with Trichostatin A (TSA) or caffeine were collected and investigated. We found that: (1) spontaneous parthenogenetic activation, developmental potential (cleavage rate), and zona pellucida (ZP) hardening undergo age-dependent changes in in vivo, in vitro, and after TSA or caffeine treatment; (2) in vivo, oocytes became spontaneously parthenogenetic 25 h post-hCG treatment; (3) in vitro, cumulus cells did not significantly increase the parthenogenetic activation rate of cultured hamster oocytes; and (4) TSA or caffeine could delay spontaneous oocyte parthenogenetic activation and the aging processes by at least 5h, but also accelerated the hardening of the ZP. These results define the conditions for the aging and anti-aging processes in golden hamster oocytes. TSA and caffeine play roles in controlling spontaneous activation, which could facilitate the storage and use of golden hamster oocytes for studying processes relevant to human reproduction. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. Determination of elements in blood of golden hamster by NAA; Determinacao de elementos em sangue de hamster dourado usando AAN

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Rodrigo Oliveira de

    2009-07-01

    In the present study Neutron Activation Analysis technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of golden hamster. The normal range for Br, Ca, Cl K, Mg, Na and S considering 2 {sigma} (Two Standard deviations) was 0.011 0.047 gL{sup -1} (Br); 0.11 0.35 gL{sup -1} (Ca); 2.11 3.75 gL{sup -1} (Cl); 1.35 2.79 gL{sup -1} (K), 0.026 0.090 gL{sup -1} (Mg), 1.03 2.51 gL{sup -1} (Na) e 0.97 2.01 gL{sup -1} (S). The knowledge of these limits became possible to perform clinical investigation in this animal model using whole blood. The comparison with the results from human being whole blood estimation (Hamster and human) became possible to check the similarities or physiologic differences, an important data for animal experimentation. (author)

  18. Postimplantation Whole Embryo Culture Assay for Hamsters: An Alternative to Rat and Mouse

    Directory of Open Access Journals (Sweden)

    Bogdan Wlodarczyk

    2001-01-01

    Full Text Available Postimplantation whole embryo culture (WEC assay for rats and mice has been well established and introduced to many laboratories. Recently WEC technique for rabbits has been developed; however, information on culture of other species is very limited. Knowing the usefulness of hamsters in classical embryotoxicology, we reasoned that hamster WEC could be an alternative model for the most frequently used rat and mouse WEC. Previously we have optimized culture conditions for postimplantation hamster embryos. The aim of this study was to test the susceptibility of hamster embryos cultured in vitro to embryotoxic compounds and to compare our results with those reported by others on rat or mouse embryo culture. For that purpose we choose three known embryotoxic compounds�valproic acid, cadmium chloride, and diethylstilbestrol�and tested them using a postimplantation hamster whole embryo culture assay. Hamster embryos were cultured from 7.5 days gestation for 24 h in a medium consisting of 35% hamster serum and 65% synthetic culture medium (Iscove�s or McCoy 5A. At the end of the culture period, the embryos were examined morphologically, measured with the aid of a computer image analysis system, and total protein content was assessed. All three compounds exhibited dose-related embryotoxic and teratogenic effects in hamster embryos. The malformations observed were similar to those reported on rat and mouse embryos. Comparison of the results with data reported by other authors indicates that hamster embryos cultured in vitromight be more susceptible to embryotoxic stimuli than rat and mouse embryos.

  19. A new search for thermotolerant yeasts, its characterization and optimization using response surface methodology for ethanol production

    Directory of Open Access Journals (Sweden)

    Richa eArora

    2015-09-01

    Full Text Available The progressive rise in energy crisis followed by green house gas (GHG emissions is serving as the driving force for bioethanol production from renewable resources. Current bioethanol research focuses on lignocellulosic feedstocks as these are abundantly available, renewable, sustainable and exhibit no competition between the crops for food and fuel. However, the technologies in use have some drawbacks including incapability of pentose fermentation, reduced tolerance to products formed, costly processes, etc. Therefore, the present study was carried out with the objective of isolating hexose and pentose fermenting thermophilic/ thermotolerant ethanologens with acceptable product yield. Two thermotolerant isolates, NIRE-K1 and NIRE-K3 were screened for fermenting both glucose and xylose and identified as Kluyveromyces marxianus NIRE-K1 and K. marxianus NIRE-K3. After optimization using FCCD (Face-centered Central Composite Design, the growth parameters like temperature and pH were found to be 45.17 oC and 5.49, respectively for K. marxianus NIRE-K1 and 45.41 oC and 5.24, respectively for K. marxianus NIRE-K3. Further, batch fermentations were carried out under optimized conditions, where K. marxianus NIRE-K3 was found to be superior over K. marxianus NIRE-K1. Ethanol yield (Yx/s, sugar to ethanol conversion rate (%, microbial biomass concentration (X and volumetric product productivity (Qp obtained by K. marxianus NIRE-K3 were found to be 9.3%, 9.55%, 14.63% and 31.94% higher than that of K. marxianus NIRE-K1, respectively. This study revealed the promising potential of both the screened thermotolerant isolates for bioethanol production.

  20. Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505.

    Directory of Open Access Journals (Sweden)

    María A Correa Deza

    Full Text Available In this work, the thermotolerance of Lactobacillus rhamnosus CRL1505, an immunobiotic strain, was studied as a way to improve the tolerance of the strain to industrial processes involving heat stress. The strain displayed a high intrinsic thermotolerance (55°C, 20 min; however, after 5 min at 60°C in phosphate buffer a two log units decrease in cell viability was observed. Different heat shock media were tested to improve the cell survival. Best results were obtained in the mediumcontaining inorganic salts (KH2PO4, Na2HPO4, MnSO4, and MgSO4 likely as using 10% skim milk. Flow cytometry analysis evinced 25.0% live cells and a large number of injured cells (59.7% in the inorganic salts medium after heat stress. The morphological changes caused by temperature were visualized by transmission electronic microscopy (TEM. In addition, TEM observations revealed the presence of polyphosphate (polyP granules in the cells under no-stress conditions. A DAPI-based fluorescence technique, adjusted to Gram-positive bacteria for the first time, was used to determine intracellular polyP levels. Results obtained suggest that the high initial polyP content in L. rhamnosus CRL 1505 together with the presence of inorganic salts in the heat shock medium improve the tolerance of the cells to heat shock. To our knowledge, this is the first report giving evidence of the relationship between polyP and inorganic salts in thermotolerance of lactic acid bacteria.

  1. Hyperthermia combined with 5-fluorouracil promoted apoptosis and enhanced thermotolerance in human gastric cancer cell line SGC-7901

    Directory of Open Access Journals (Sweden)

    Liu T

    2015-05-01

    Full Text Available Tao Liu,* Yan-Wei Ye,* A-li Zhu, Zhen Yang, Yang Fu, Chong-Qing Wei, Qi Liu, Chun-Lin Zhao, Guo-Jun Wang, Xie-Fu Zhang Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People’s Republic of China *These authors contributed equally to this work Abstract: This study was designed to investigate the proliferation inhibition and apo­ptosis-promoting effect under hyperthermia and chemotherapy treatment, at cellular level. Human gastric cancer cell line SGC-7901 was cultivated with 5-fluorouracil at different temperatures. Cell proliferation and apoptosis were determined, and expression of Bcl-2 and HSP70 was measured at different treatments. Cell survival rates and inhibition rates in chemotherapy group, thermotherapy group, and thermo-chemotherapy group were drastically lower than the control group (P<0.05. For tumor cells in the thermo-chemotherapy group, survival rates and inhibition rates at three different temperatures were all significantly lower than those in chemotherapy group and thermotherapy group (P<0.05. 5-Fluorouracil induced apoptosis of SGC-7901 cells with a strong temperature dependence, which increased gradually with increase in temperature. At 37°C and 43°C there were significant differences between the thermotherapy group and chemotherapy group and between the thermo-chemotherapy group and thermotherapy group (P<0.01. The expression of Bcl-2 was downregulated and HSP70 was upregulated, with increase in temperature in all groups. Cell apoptosis was not significant at 46°C (P>0.05, which was probably due to thermotolerance caused by HSP70 accumulation. These results suggested that hyperthermia combined with 5-fluorouracil had a synergistic effect in promoting apoptosis and enhancing thermotolerance in gastric cancer cell line SGC-7901. Keywords: gastric cancer, thermotherapy, 5-fluorouracil, Bcl-2, HSP70, thermotolerance

  2. Improved ethanol production of a newly isolated thermotolerant Saccharomyces cerevisiae strain after high-energy-pulse-electron beam.

    Science.gov (United States)

    Zhang, Q; Fu, Y; Wang, Y; Han, J; Lv, J; Wang, S

    2012-02-01

    To isolate thermotolerant Saccharomyces cerevisiae with high-energy-pulse-electron (HEPE) beam, to optimize the mutation strain fermentation conditions for ethanol production and to conduct a preliminary investigation into the thermotolerant mechanisms. After HEPE beam radiation, the thermotolerant S. cerevisiae strain Y43 was obtained at 45°C. Moreover, the fermentation conditions of mutant Y43 were optimized by L3(3) orthogonal experiment. The optimal glucose content and initial pH for fermentation were 20% g l(-1) and 4·5, respectively; peptone content was the most neglected important factor. Under this condition, ethanol production of Y43 was 83·1 g l(-1) after fermentation for 48 h at 43°C, and ethanol yield was 0·42 g g(-1), which was about 81·5% of the theoretical yield. The results also showed that the trehalose content and the expression of the genes MSN2, SSA3 and TPS1 in Y43 were higher than those in the original strain (YE0) under the same stress conditions. A genetically stable mutant strain with high ethanol yield under heat stress was obtained using HEPE. This mutant may be a suitable candidate for the industrial-scale ethanol production. High-energy-pulse-electron radiation is a new efficient technology in breeding micro-organisms. The mutant obtained in this work has the advantages in industrial ethanol production under thermostress. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  3. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2015-01-01

    adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40°C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses...... in the ancestral strain. The latter is an advantageous attribute for acquiring thermotolerance and correlates with the reduction of yeast functions associated with loss of respiration capacity. This trait caused glycerol overproduction that was associated with the growth trade-off at ancestral temperatures...

  4. Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climates.

    Science.gov (United States)

    Marias, Danielle E; Meinzer, Frederick C; Woodruff, David R; McCulloh, Katherine A

    2017-03-01

    Temperature and the frequency and intensity of heat waves are predicted to increase throughout the 21st century. Germinant seedlings are expected to be particularly vulnerable to heat stress because they are in the boundary layer close to the soil surface where intense heating occurs in open habitats. We quantified leaf thermotolerance and whole-plant physiological responses to heat stress in first-year germinant seedlings in two populations each of Pinus ponderosa P. and C. Lawson (PIPO) and Pseudotsuga menziesii (Mirb.) Franco (PSME) from climates with contrasting precipitation and temperature regimes. Thermotolerance of detached needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. PSME was more heat tolerant than PIPO according to both independent assessments of thermotolerance. Following exposure of whole seedlings to a simulated heat wave at 45 °C for 1 h in a growth chamber, we monitored FV/FM, photosynthesis, stomatal conductance, non-structural carbohydrates (NSCs) and carbon isotope ratios (δ13C) for 14 days. Heat treatment induced significant reductions in FV/FM in both species and a transient reduction in photosynthetic gas exchange only in PIPO 1 day after treatment. Heat treatment induced an increase in glucose + fructose concurrent with a decrease in starch in both species, whereas total NSC and sucrose were not affected by heat treatment. The negative relationship between glucose + fructose and starch observed in treated plants may be due to the conversion of starch to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites displayed greater δ13C values than those from wetter sites, consistent with higher intrinsic water-use efficiency and drought resistance of populations from drier climates. Thermotolerance and heat stress responses appeared to be phenotypically plastic and representative of the environment in which plants were grown, whereas intrinsic water-use efficiency

  5. Association of ATP1A1 gene polymorphism with thermotolerance in Tharparkar and Vrindavani cattle

    Directory of Open Access Journals (Sweden)

    Neeraj Kashyap

    2015-07-01

    Full Text Available Aim: One of the major biochemical aspects of thermoregulation is equilibrium of ion gradient across biological membranes. Na+/K+-ATPase, a member of P type-ATPase family, is a major contributor to the mechanism that actively controls crossmembrane ion gradient. Thus, we examined ATP1A1 gene that encodes alpha-1 chain of Na+/K+-ATPase, for genetic polymorphisms. Materials and Methods: A total of 100 Vrindavani (composite cross strain of Hariana x Holstein-Friesian/Brown Swiss/Jersey and 64 Tharparkar (indigenous cattle were screened for genetic polymorphism in ATP1A1 gene, using polymerase chain reaction single-strand conformation polymorphism and DNA sequencing. For association studies, rectal temperature (RT and respiration rate (RR of all animals were recorded twice daily for 3 seasons. Results: A SNP (C2789A was identified in exon 17 of ATP1A1 gene. Three genotypes namely CC, CA, and AA were observed in both, Vrindavani and Tharparkar cattle. The gene frequencies in Tharparkar and Vrindavani for allele A were 0.51 and 0.48, and for allele C were 0.49 and 0.52, respectively, which remained at intermediate range. Association study of genotypes with RT and RR in both cattle population revealed that the animals with genotype CC exhibited significantly lower RT and higher heat tolerance coefficient than CA and AA genotypes. Conclusion: Differential thermoregulation between different genotypes of ATP1A1 gene indicate that the ATP1A1 gene could be potentially contributing to thermotolerance in both, Tharparkar, an indigenous breed and Vrindavani, a composite crossbred cattle.

  6. L: (+)-Lactic acid production from non-food carbohydrates by thermotolerant Bacillus coagulans.

    Science.gov (United States)

    Ou, Mark S; Ingram, Lonnie O; Shanmugam, K T

    2011-05-01

    Lactic acid is used as an additive in foods, pharmaceuticals, and cosmetics, and is also an industrial chemical. Optically pure lactic acid is increasingly used as a renewable bio-based product to replace petroleum-based plastics. However, current production of lactic acid depends on carbohydrate feedstocks that have alternate uses as foods. The use of non-food feedstocks by current commercial biocatalysts is limited by inefficient pathways for pentose utilization. B. coagulans strain 36D1 is a thermotolerant bacterium that can grow and efficiently ferment pentoses using the pentose-phosphate pathway and all other sugar constituents of lignocellulosic biomass at 50°C and pH 5.0, conditions that also favor simultaneous enzymatic saccharification and fermentation (SSF) of cellulose. Using this bacterial biocatalyst, high levels (150-180 g l(-1)) of lactic acid were produced from xylose and glucose with minimal by-products in mineral salts medium. In a fed-batch SSF of crystalline cellulose with fungal enzymes and B. coagulans, lactic acid titer was 80 g l(-1) and the yield was close to 80%. These results demonstrate that B. coagulans can effectively ferment non-food carbohydrates from lignocellulose to L: (+)-lactic acid at sufficient concentrations for commercial application. The high temperature fermentation of pentoses and hexoses to lactic acid by B. coagulans has these additional advantages: reduction in cellulase loading in SSF of cellulose with a decrease in enzyme cost in the process and a reduction in contamination of large-scale fermentations.

  7. Decolorization of a recalcitrant organic compound (Melanoidin by a novel thermotolerant yeast, Candida tropicalis RG-9

    Directory of Open Access Journals (Sweden)

    Tiwari Soni

    2012-06-01

    Full Text Available Abstract Background Sugarcane distilleries use molasses for ethanol production and generate large volume of effluent containing high biological oxygen demand (BOD and chemical oxygen demand (COD along with melanoidin pigment. Melanoidin is a recalcitrant compound that causes several toxic effects on living system, therefore, may be treated before disposal. The aim of this study was to isolate a potential thermotolerant melanoidin decolorizing yeast from natural resources, and optimized different physico-chemical and nutritional parameters. Results Total 24 yeasts were isolated from the soil samples of near by distillery site, in which isolate Y-9 showed maximum decolorization and identified as Candida tropicalis by Microbial Type Culture Collection (MTCC Chandigarh, India. The decolorization yield was expressed as the decrease in the absorbance at 475 nm against initial absorbance at the same wavelength. Uninoculated medium served as control. Yeast showed maximum decolorization (75% at 45°C using 0.2%, glucose; 0.2%, peptone; 0.05%, MgSO4; 0.01%, KH2PO4; pH-5.5 within 24 h of incubation under static condition. Decolorizing ability of yeast was also confirmed by high performance liquid chromatography (HPLC analysis. Conclusion The yeast strain efficiently decolorized melanoidin pigment of distillery effluent at higher temperature than the other earlier reported strains of yeast, therefore, this strain could also be used at industrial level for melanoidin decolorization as it tolerated a wide range of temperature and pH with very small amount of carbon and nitrogen sources.

  8. Cloning, Expression, and Characterization of Thermotolerant Manganese Superoxide Dismutase from Bacillus sp. MHS47

    Directory of Open Access Journals (Sweden)

    Supatra Areekit

    2011-01-01

    Full Text Available A superoxide dismutase gene from thermotolerant Bacillus sp. MHS47 (MnSOD47 was cloned, sequenced, and expressed. The gene has an open reading frame of 612 bp, corresponding to 203 deduced amino acids, with high homology to the amino acid sequences of B. thuringiensis (accession no. EEN01322, B. anthracis (accession no. NP_846724, B. cereus (accession no. ZP_04187911, B. weihenstephanensis (accession no. YP_001646918, and B. pseudomycoides. The conserved manganese-binding sites (H28, H83, D165, and H169 show that MnSOD47 has the specific characteristics of the manganese superoxide dismutase (MnSOD enzymes. MnSOD47 expressed an enzyme with a molecular weight of approximately 22.65 kDa and a specific activity of 3537.75 U/mg. The enzyme is active in the pH range 7–8.5, with an optimum pH of 7.5, and at temperatures in the range 30–45 °C, with an optimum temperature of 37 °C. Tests of inhibitors and metal ions indicated that the enzyme activity is inhibited by sodium azide, but not by hydrogen peroxide or potassium cyanide. These data should benefit future studies of MnSODs in other microorganisms and the biotechnological production of MnSOD47, and could also be used to develop a biosensor for the detection of antioxidants and free radical activity. In the future, this basic knowledge could be applicable to the detection of cancer risks in humans and therapeutic treatments.

  9. Biosorption of heavy metal by thermotolerant polymerproducing bacterial cells and the bioflocculant

    Directory of Open Access Journals (Sweden)

    Saithong Kaewchai

    2002-07-01

    Full Text Available Three strains of thermotolerant polymer-producing bacteria; Bacillus subtilis WD 90, Bacillus subtilis SM 29, and Enterobacter agglomerans SM 38 as well as their biofloculants were used to investigate on the adsorption of heavy metal, nickel and cadmium. The effects of pH and concentrations of heavy metal were investigated. The optimum pH for nickel and cadmium adsorption by the dried cells of E. agglomerans SM 38 were found to be 7.0 (25.5% removal and 8.0 (32% removal, respectively. For B. subtilis WD 90 and B. subtilis SM 29, the optimum pH at 8.0 exhibited the nickel removal of 27% and 25%, respectively, and cadmium removal of 28% and 28.5%, respectively. The heavy metal adsorption by the dried cells and wet cells of E. agglomerans SM 38 were slightly increased with increasing initial concentrations of nickel and cadmium up to 60 and 30 ppm, respectively. The bioflocculant of B. subtilis WD 90 and B. subtilis SM 29 showed the highest nickel removal of 90.7% and 87.0% respectively, while the cadmium removal was 90.9 and 91.4%, respectively. The optimum pH for adsorption of both nickel and cadmium by the bioflocculant of E. agglomerans SM 38 was 7.0 with the removal of 92.8 and 84.2%, respectively. The optimum nickel concentration for adsorption by the bioflocculant of E. agglomerans SM 38 was 10 ppm, with the removal of 92.5%, and rather stable up to 60 ppm. The optimum cadmium concentration for adsorption by the bioflocculant of B. subtilis SM 29 was 60 ppm at pH 8.0 with the removal of 85.7%. Therefore, the bioflocculant of the three isolates gave higher heavy metal adsorption than the cells.

  10. Occurrence of thermotolerant Campylobacter spp. at different stages of the poultry meat supply chain in Argentina.

    Science.gov (United States)

    Zbrun, M V; Romero-Scharpen, A; Olivero, C; Rossler, E; Soto, L P; Rosmini, M R; Sequeira, G J; Signorini, M L; Frizzo, L S

    2013-11-01

    The objectives of this study were to investigate the occurrence and concentration of thermotolerant Campylobacter spp. at different stages of the poultry meat supply chain in Argentina. Three integrated poultry companies were sampled. Each supply chain was considered at different stages from the reproductive farm to chicken meat at a retail market. The stages sampled were: (a) hens from breeder flocks, (b) eggs in the incubator, (c) broiler chickens in flocks (aged 5 weeks), (d) chickens at a slaughterhouse, and (e) chicken meat at a retail market. The chickens sampled along each supply chain were in the same batch. Samples collected were: (a) cloacal samples from hens and chickens on the farms, (b) fertile eggs, (c) feed, water and litter from flocks, (d) chicken carcasses from the slaughterhouse and retail market, and (e) caeca and livers from the slaughterhouse. Samples obtained were examined for Campylobacter spp. The isolates were biotyped and the genus and species identified by PCR. Campylobacter spp. on chicken carcasses at slaughterhouse and retail market were enumerated. The highest proportions of Campylobacter positive samples were observed in carcasses at retail (25/30, 83.3%) and faecal samples from breeding hens (27/45, 60.0%). Only 3.3% (3/90) samples collected from broiler chickens aged meat in Argentina. The proportions of Campylobacter-positive samples found in this preliminary study indicate that a large proportion of the cases of human gastroenteritis in Argentina may be due to this pathogen. Human cases of gastroenteritis should be studied in greater detail and measures should be developed to reduce the proportion of poultry products that are contaminated by Campylobacter species.

  11. Production, purification and characterization of a thermotolerant alkaline serine protease from a novel species Bacillus caseinilyticus.

    Science.gov (United States)

    Mothe, Thirumala; Sultanpuram, Vishnuvardhan Reddy

    2016-06-01

    Alkaline proteases are important enzymes in many industrial applications, especially as additives in laundry detergent industry. Though there are a number of Bacillus species which are reported to be producing proteases, the efficiency of a protease produced by a novel strain has to be studied in comparison to the others. Hence, in this study, an alkaline serine protease produced by a novel species Bacillus caseinilyticus was purified and characterized for its possible usage in detergent industry. Ammonium sulphate, dialysis and DEAE column chromatographic methods were used for purification of the isolated alkaline protease. The molecular weight of the protease was determined by SDS-PAGE and it was found to be 66 kDa. Peptide mass fingerprinting (PMF) was carried out using MALDI-TOF-TOF mass spectrometry and the peptides were found to be similar to that of subtilisin protease. Specific activity of purified protein was found to be 89.2 U/mg. Optimum pH and temperature for enzyme activity were at pH 8 and 60 °C, respectively, showing stability with 10 mM CaCl 2 . Phenyl methyl sulphonyl fluoride (PMSF) at both 5 and 10 mM concentrations completely inhibited the enzyme activity suggesting its serine nature. EDTA, metal ions Mg 2+ and Ca 2+ increased the enzyme activity. The one factor at a time optimisation of the protease production was carried to identify the important factors that affect its production. After optimisation, the protease was produced at lab scale, purified and characterised. This alkali, thermotolerant serine protease was found to be significantly stable in the presence of various surfactants and H 2 O 2. Also, it was successfully able to remove blood stain when used as an additive along with commercial detergent suggesting its potential application in the laundry detergent industry.

  12. Estudios inmunologicos en hamsters (Cricetus auratus infectados con Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Eduardo Monge

    1986-08-01

    Full Text Available Los resultados de este trabajo muestran que el hamster (Cricetus auratus puede ser utilizado como un modelo experimental para estudios inmunológicos en la infección por Schistosoma mansoni. Los datos obtenidos, relativos a inmunidad concomitante, producción de anticuerpo letal e inmunosupresión se asemejan a los conseguidos en otros modelos experimentales ya establecidos. Estas observaciones indican que el hámster, además de ser un hospedero satisfactorio para el mantenimiento del parásito en el laboratorio, puede ser considerado como un modelo experimental alterno cuyo crecimiento y mantenimiento son relativamente simples y además es un animal de fácil manejo.

  13. Thyroid function and cold acclimation in the hamster, Mesocricetus auratus

    International Nuclear Information System (INIS)

    Tomasi, T.E.; Horwitz, B.A.

    1987-01-01

    Basal metabolic rate (BMR), thyroxine utilization rate (T 4 U), and triiodothyronine utilization rate (T 3 U) were measured in cold-acclimated (CA) and room temperature-acclimated (RA) male golden hamsters, Mesocricetus auratus. Hormone utilization rates were calculated via the plasma disappearance technique using 125 I-labeled hormones and measuring serum hormone levels via radioimmunoassay. BMR showed a significant 28% increase with cold acclimation. The same cold exposure also produced a 32% increase in T 4 U, and a 204% increase in T 3 U. The much greater increase in T 3 U implies that previous assessments of the relationship between cold acclimation and thyroid function may have been underestimated and that cold exposure induces both quantitative and qualitative changes in thyroid function. It is concluded that in the cold-acclimated state, T 3 U more accurately reflects thyroid function than does T 4 U. A mechanism for the cold-induced change in BMR is proposed

  14. Genome-wide identification, classification, and analysis of heat shock transcription factor family in Chinese cabbage (Brassica rapa pekinensis).

    Science.gov (United States)

    Huang, X Y; Tao, P; Li, B Y; Wang, W H; Yue, Z C; Lei, J L; Zhong, X M

    2015-03-27

    Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetable crops grown worldwide, and various methods exist for selection, propagation, and cultivation. The entire Chinese cabbage genome has been sequenced, and the heat shock transcription factor family (Hsfs) has been found to play a central role in plant growth and development and in the response to biotic and abiotic stress conditions, particularly in acquired thermotolerance. We analyzed heat tolerance mechanisms in Chinese cabbage. In this study, 30 Hsfs were identified from the Chinese cabbage genome database. The classification, phylogenetic reconstruction, chromosome distribution, conserved motifs, expression analysis, and interaction networks of the Hsfs were predicted and analyzed. Thirty BrHsfs were classified into 3 major classes (class A, B, and C) according to their structural characteristics and phylogenetic comparisons, and class A was further subdivided into 8 subclasses. Distribution mapping results showed that Hsf genes were located on 10 Chinese cabbage chromosomes. The expression profile indicated that Hsfs play differential roles in 5 organs in Chinese cabbage, and likely participate in the development of underground parts and regulation of reproductive growth. An orthologous gene interaction network was constructed, and included MBF1C, ROF1, TBP2, CDC2, and HSP70 5 genes, which are closely related to heat stress. Our results contribute to the understanding of the complexity of Hsfs in Chinese cabbage and provide a basis for further functional gene research.

  15. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

    Directory of Open Access Journals (Sweden)

    Barbara Noli

    Full Text Available VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA coupled with high-performance liquid (HPLC or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.

  16. Transmission of methicillin-resistant Staphylococcus aureus between human and hamster.

    Science.gov (United States)

    Ferreira, Jorge Pinto; Fowler, Vance G; Correa, Maria T; Lyman, Roberta; Ruffin, Felicia; Anderson, Kevin L

    2011-04-01

    Transmission of methicillin-resistant Staphylococcus aureus (MRSA) between humans and animals is increasingly recognized. We newly document that the transmission of MRSA between human and hamster is possible.

  17. Non-parametric photic entrainment of Djungarian hamsters with different rhythmic phenotypes

    Czech Academy of Sciences Publication Activity Database

    Schöttner, Konrad; Hauer, J.; Weinert, D.

    2016-01-01

    Roč. 33, č. 5 (2016), s. 506-519 ISSN 0742-0528 Institutional support: RVO:60077344 Keywords : delayed activity onset * Djungarian hamster * free-running period Subject RIV: ED - Physiology Impact factor: 2.562, year: 2016

  18. Familial incidence of mammary gland tumours in the Djungarian hamster (Phodopus sungaros): a case report

    Czech Academy of Sciences Publication Activity Database

    Jelínek, F.; Felsberg, Jürgen; Měšťan, M.

    2013-01-01

    Roč. 58, č. 8 (2013), s. 442-448 ISSN 0375-8427 Institutional support: RVO:61388971 Keywords : hamsters * neoplasias * atypical fibrosarcoma Subject RIV: EE - Microbiology, Virology Impact factor: 0.756, year: 2013

  19. Necator americanus and Ancylostoma ceylanicum: development of protocols for dual infection in hamsters.

    Science.gov (United States)

    Rajasekariah, G R; Dhage, K R; Deb, B N; Bose, S

    1985-03-01

    Two-day-old baby hamsters were infected initially with the infective larvae of hamster-adapted human hookworm, Necator americanus (NaL3). After a specified period they were again infected orally with infective larvae of Ancylostoma ceylanicum (AcL3). Three weeks after the second infection they were killed and the establishment of N. americanus and A. ceylanicum was assessed. The effect of different infection levels and exposure period of N. americanus on the concurrent establishment of A. ceylanicum was also examined. An infection with 50 NaL3 percutaneously, and 3 weeks later, a second infection with 50 AcL3 orally has produced reasonably equal number of hookworms (no statistical difference in the burden of N. americanus and A. ceylanicum) in the intestine of hamsters. Thus this protocol of dual infection was found suitable to develop two species of hookworms in hamsters for anthelmintic screening.

  20. Allometric and radioautographic study on developing parotid gland of the golden hamster at early postnatat period

    International Nuclear Information System (INIS)

    Luca, I.M.S. de

    1989-01-01

    The post-natal development of golden hamster parotid gland and the rate of proliferation of the cells are studied in the first month of the life. A comparative evaluation with other rodents is presented. (M.A.C.) [pt

  1. Seasonal adaptation of dwarf hamsters (Genus Phodopus): differences between species and their geographic origin.

    Science.gov (United States)

    Müller, D; Hauer, J; Schöttner, K; Fritzsche, P; Weinert, D

    2015-12-01

    The genus Phodopus consists of three species--P. campbelli (Pc), P. sungorus (Ps), and P. roborovskii (Pr). They inhabit steppes, semi-deserts, and deserts in continental Asia with a climate changing from a moderate to a hard Continental one with extreme daily and seasonal variations. These different environmental challenges are likely to have consequences for hamsters' morphology, physiology, and behavior. Hamsters of all three species were investigated during the course of the year in the laboratory though using natural lighting and temperature conditions. Motor activity and body temperature were measured continuously, and body mass, testes size, and fur coloration every 1-2 weeks. With regard to the pattern of activity, nearly twice as many Pc as Ps hamsters (25 vs. 14%) failed to respond to changes of photoperiod, whereas all Pr hamsters did. Body mass and testes size were high in summer and low in winter, with the biggest relative change in Ps and the lowest in Pr hamsters. Changes of fur coloration were found in Ps hamsters only. All responding animals (that is excluding Pr), exhibited regular torpor bouts during the short winter days. In autumn, seasonal changes started considerably earlier in Ps hamsters. To investigate the putative causes of these different time courses, a further experiment was performed, to identify the critical photoperiod. Hamsters were kept for 10 weeks under different photoperiods, changing from 16 to 8 h light per day. Motor activity was recorded continuously, to identify responding and non-responding animals. Body mass was measured at the beginning and the end of the experiment, testes mass only at the end. The critical photoperiod was found to be similar in all three species. Though in a further experiment, Pc and Pr hamsters showed a delayed response, whereas the changes in Ps hamsters started immediately following transfer to short-day conditions. The results show that interspecific differences in seasonal adaptation exist, even

  2. Physiological responses in a variable environment: relationships between metabolism, hsp and thermotolerance in an intertidal-subtidal species.

    Directory of Open Access Journals (Sweden)

    Yun-wei Dong

    Full Text Available Physiological responses to temperature reflect the evolutionary adaptations of organisms to their thermal environment and the capability of animals to tolerate thermal stress. Contrary to conventional metabolism theory, increasing environmental temperatures have been shown to reduce metabolic rate in rocky-eulittoral-fringe species inhabiting highly variable environments, possibly as a strategy for energy conservation. To study the physiological adaptations of an intertidal-subtidal species to the extreme and unpredictable heat stress of the intertidal zone, oxygen consumption rate and heat shock protein expression were quantified in the sea cucumber Apostichopus japonicus. Using simulate natural temperatures, the relationship between temperature, physiological performance (oxygen consumption and heat shock proteins and thermotolerance were assessed. Depression of oxygen consumption rate and upregulation of heat shock protein genes (hsps occurred in sequence when ambient temperature was increased from 24 to 30°C. Large-scale mortality of the sea cucumber occurred when temperatures rose beyond 30°C, suggesting that the upregulation of heat shock proteins and mortality are closely related to the depression of aerobic metabolism, a phenomenon that is in line with the concept of oxygen- and capacity-limited thermal tolerance (OCLTT. The physiologically-related thermotolerance of this sea cucumber should be an adaptation to its local environment.

  3. Removal of Total Coliforms, Thermotolerant Coliforms, and Helminth Eggs in Swine Production Wastewater Treated in Anaerobic and Aerobic Reactors

    Science.gov (United States)

    Zacarias Sylvestre, Silvia Helena; Lux Hoppe, Estevam Guilherme; de Oliveira, Roberto Alves

    2014-01-01

    The present work evaluated the performance of two treatment systems in reducing indicators of biological contamination in swine production wastewater. System I consisted of two upflow anaerobic sludge blanket (UASB) reactors, with 510 and 209 L in volume, being serially arranged. System II consisted of a UASB reactor, anaerobic filter, trickling filter, and decanter, being also organized in series, with volumes of 300, 190, 250, and 150 L, respectively. Hydraulic retention times (HRT) applied in the first UASB reactors were 40, 30, 20, and 11 h in systems I and II. The average removal efficiencies of total and thermotolerant coliforms in system I were 92.92% to 99.50% and 94.29% to 99.56%, respectively, and increased in system II to 99.45% to 99.91% and 99.52% to 99.93%, respectively. Average removal rates of helminth eggs in system I were 96.44% to 99.11%, reaching 100% as in system II. In reactor sludge, the counts of total and thermotolerant coliforms ranged between 105 and 109 MPN (100 mL)−1, while helminth eggs ranged from 0.86 to 9.27 eggs g−1 TS. PMID:24812560

  4. An immunomagnetic separation/loop-mediated isothermal amplification method for rapid direct detection of thermotolerant Campylobacter spp. during poultry production.

    Science.gov (United States)

    Romero, M R; D'Agostino, M; Arias, A Pérez; Robles, S; Casado, C Fernández; Iturbe, L Orueta; Lerma, O Gurrutxaga; Andreou, M; Cook, N

    2016-02-01

    To develop a rapid test for thermotolerant Campylobacter in poultry faeces. The reported method is based on immunomagnetic separation and loop-mediated isothermal DNA amplification (IMS/LAMP). This LAMP assay is specific (demonstrated using 10 Campylobacter strains and 13 non-Campylobacter bacterial species) and sensitive (95% probability of detecting 22 genome copies). A competitive internal amplification control (IAC) has been incorporated to give unambiguous determination of negative results. Immunoseparation of Campylobacter allows direct LAMP detection from poultry boot swab samples in 90 min without enrichment or DNA purification (74% probability of detecting 10(4) CFU ml(-1) of a boot swab suspension). The analysis of 17 samples from commercial turkey farms showed 100% correlation with parallel results obtained by standard microbiological methods. A rapid test has been developed for direct detection of thermotolerant Campylobacter spp. in boot swab samples, thus bypassing culture enrichment or DNA extraction. The test has potential to be carried out by farm personnel on site. The method offers an inexpensive approach to monitor poultry infection in near real time, assisting flock management and controls to prevent introduction of Campylobacter into the food chain. © 2015 The Society for Applied Microbiology.

  5. Contributory roles of two l-lactate dehydrogenases for l-lactic acid production in thermotolerant Bacillus coagulans.

    Science.gov (United States)

    Sun, Lifan; Zhang, Caili; Lyu, Pengcheng; Wang, Yanping; Wang, Limin; Yu, Bo

    2016-11-25

    Thermotolerant Bacillus coagulans is considered to be a more promising producer for bio-chemicals, due to its capacity to withstand harsh conditions. Two L-lactate dehydrogenase (LDH) encoding genes (ldhL1 and ldhL2) and one D-LDH encoding gene (ldhD) were annotated from the B. coagulans DSM1 genome. Transcriptional analysis revealed that the expression of ldhL2 was undetectable while the ldhL1 transcription level was much higher than that of ldhD at all growth phases. Deletion of the ldhL2 gene revealed no difference in fermentation profile compared to the wild-type strain, while ldhL1 single deletion or ldhL1ldhL2 double deletion completely blocked L-lactic acid production. Complementation of ldhL1 in the above knockout strains restored fermentation profiles to those observed in the wild-type strain. This study demonstrates ldhL1 is crucial for L-lactic acid production and NADH balance in B. coagulans DSM1 and lays the fundamental for engineering the thermotolerant B. coagulans strain as a platform chemicals producer.

  6. Thermotolerant Kluyveromyces marxianus and Saccharomyces cerevisiae strains representing potentials for bioethanol production from Jerusalem artichoke by consolidated bioprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Nan [Agricultural Univ., Qingdao, SD (China). College of Animal Science and Technology; Chinese Academy of Sciences, Qingdao, SD (China). Key Lab. of Biofuels; Yuan, Bo; Wang, Shi-An; Li, Fu-Li [Chinese Academy of Sciences, Qingdao, SD (China). Key Lab. of Biofuels; Sun, Juan [Agricultural Univ., Qingdao, SD (China). College of Animal Science and Technology

    2012-09-15

    Thermotolerant inulin-utilizing yeast strains are desirable for ethanol production from Jerusalem artichoke tubers by consolidated bioprocessing (CBP). To obtain such strains, 21 naturally occurring yeast strains isolated by using an enrichment method and 65 previously isolated Saccharomyces cerevisiae strains were investigated in inulin utilization, extracellular inulinase activity, and ethanol fermentation from inulin and Jerusalem artichoke tuber flour at 40 C. The strains Kluyveromyces marxianus PT-1 (CGMCC AS2.4515) and S. cerevisiae JZ1C (CGMCC AS2.3878) presented the highest extracellular inulinase activity and ethanol yield in this study. The highest ethanol concentration in Jerusalem artichoke tuber flour fermentation (200 g L{sup -1}) at 40 C achieved by K. marxianus PT-1 and S. cerevisiae JZ1C was 73.6 and 65.2 g L{sup -1}, which corresponded to the theoretical ethanol yield of 90.0 and 79.7 %, respectively. In the range of 30 to 40 C, temperature did not have a significant effect on ethanol production for both strains. This study displayed the distinctive superiority of K. marxianus PT-1 and S. cerevisiae JZ1C in the thermotolerance and utilization of inulin-type oligosaccharides reserved in Jerusalem artichoke tubers. It is proposed that both K. marxianus and S. cerevisiae have considerable potential in ethanol production from Jerusalem artichoke tubers by a high temperature CBP. (orig.)

  7. Removal of total coliforms, thermotolerant coliforms, and helminth eggs in Swine production wastewater treated in anaerobic and aerobic reactors.

    Science.gov (United States)

    Zacarias Sylvestre, Silvia Helena; Lux Hoppe, Estevam Guilherme; de Oliveira, Roberto Alves

    2014-01-01

    The present work evaluated the performance of two treatment systems in reducing indicators of biological contamination in swine production wastewater. System I consisted of two upflow anaerobic sludge blanket (UASB) reactors, with 510 and 209 L in volume, being serially arranged. System II consisted of a UASB reactor, anaerobic filter, trickling filter, and decanter, being also organized in series, with volumes of 300, 190, 250, and 150 L, respectively. Hydraulic retention times (HRT) applied in the first UASB reactors were 40, 30, 20, and 11 h in systems I and II. The average removal efficiencies of total and thermotolerant coliforms in system I were 92.92% to 99.50% and 94.29% to 99.56%, respectively, and increased in system II to 99.45% to 99.91% and 99.52% to 99.93%, respectively. Average removal rates of helminth eggs in system I were 96.44% to 99.11%, reaching 100% as in system II. In reactor sludge, the counts of total and thermotolerant coliforms ranged between 10(5) and 10(9) MPN (100 mL)(-1), while helminth eggs ranged from 0.86 to 9.27 eggs g(-1) TS.

  8. Triazole Susceptibilities in Thermotolerant Fungal Isolates from Outdoor Air in the Seoul Capital Area in South Korea.

    Directory of Open Access Journals (Sweden)

    Seungeun Lee

    Full Text Available Emerging fungi resistant to triazoles are a concern because of the increased use of medical triazoles and exposure to agricultural triazoles. However, little is known about the levels of triazole susceptibility in outdoor airborne fungi making it difficult to assess the risks of inhalation exposure to airborne, antifungal-resistant fungi. This study examined triazole susceptibilities of the airborne thermotolerant fungi isolated from the ambient air of the Seoul Capital Area of South Korea. We used impactor air sampling with triazole-containing nutrient agar plates as the collection substrates to screen for airborne fungal isolates based on their triazole susceptibilities. This study estimated that 0.17% of all the culturable fungi belong to the pathogenic thermotolerant taxa, among which each isolate of Aspergillus niger and Aspergillus tubingensis showed a minimum inhibitory concentration (MIC of 2 μg/mL or greater for itraconazole. Their concentration in air was 0.4 CFU/m3. Seven human pathogenic Paecilomyces variotii isolates had MICs of 32 μg/mL or greater and lower than 2 μg/mL for the agricultural fungicide tebuconazole and the medical triazole itraconazole, respectively. Though the concentration was low, our results confirm the presence of airborne fungi with high MICs for itraconazole in ambient air. Inhalation is an important exposure route because people inhale more than 10 m3 of air each day. Vigilance is preferred over monitoring for the emergence of triazole-resistant fungal pathogens in ambient outdoor air.

  9. Triazole Susceptibilities in Thermotolerant Fungal Isolates from Outdoor Air in the Seoul Capital Area in South Korea

    Science.gov (United States)

    Lee, Seungeun; Xu, Siyu; Bivila, Chemmeri Padasseri; Lee, Hyeyoung; Park, Myung Soo; Lim, Young Woon; Yamamoto, Naomichi

    2015-01-01

    Emerging fungi resistant to triazoles are a concern because of the increased use of medical triazoles and exposure to agricultural triazoles. However, little is known about the levels of triazole susceptibility in outdoor airborne fungi making it difficult to assess the risks of inhalation exposure to airborne, antifungal-resistant fungi. This study examined triazole susceptibilities of the airborne thermotolerant fungi isolated from the ambient air of the Seoul Capital Area of South Korea. We used impactor air sampling with triazole-containing nutrient agar plates as the collection substrates to screen for airborne fungal isolates based on their triazole susceptibilities. This study estimated that 0.17% of all the culturable fungi belong to the pathogenic thermotolerant taxa, among which each isolate of Aspergillus niger and Aspergillus tubingensis showed a minimum inhibitory concentration (MIC) of 2 μg/mL or greater for itraconazole. Their concentration in air was 0.4 CFU/m3. Seven human pathogenic Paecilomyces variotii isolates had MICs of 32 μg/mL or greater and lower than 2 μg/mL for the agricultural fungicide tebuconazole and the medical triazole itraconazole, respectively. Though the concentration was low, our results confirm the presence of airborne fungi with high MICs for itraconazole in ambient air. Inhalation is an important exposure route because people inhale more than 10 m3 of air each day. Vigilance is preferred over monitoring for the emergence of triazole-resistant fungal pathogens in ambient outdoor air. PMID:26405807

  10. Construction of a thermotolerant Saccharomyces cerevisiae strain for bioethanol production with reduced fermentation time and saccharifying enzyme dose.

    Science.gov (United States)

    Lim, Ji Sung; Jang, You Ri; Lim, Young Hoon; Kim, Keun

    2012-10-01

    A thermotolerant Saccharomyces cerevisiae mutant strain, TT6, was constructed after multi-parental hybridization of five mutant strains obtained by UV or NTG treatment of the original strain, S. cerevisiae KV1. When incubated at 40 degrees C in YPD broth, TT6 began to grow exponentially in 10 h, but KV1 did not show any noticeable growth even after 22 h. The thermotolerant growth of TT6 was confirmed by serial dilution assay at 42 degrees C; TT6 grew at a cell concentration (10(-5)) 10,000 times lower than that of KV1 (10(-1)). Whereas ethanol production from YP containing 23%; (w/v) glucose by KV1 decreased with increasing temperature from 30 degrees C to 36 degrees C, ethanol production by TT6 did not decrease at temperatures up to 37 degrees C. When TT6 was tested for ethanol production at 36 degrees C by simultaneous saccharification and fermentation (SSF) from 23% corn, 24 h of fermentation time or 50% of the glucoamylase dose was saved when compared with KV1 at 30 degrees C. The ethanol yield from corn by SSF with TT6 at 36 degrees C was 91.7% of the theoretical yield, whereas that of KV1 at 30 degrees C was 90.6%.

  11. Experimental infection of hamsters with avian paramyxovirus serotypes 1 to 9

    Directory of Open Access Journals (Sweden)

    Samuel Arthur S

    2011-02-01

    Full Text Available Abstract Avian paramyxoviruses (APMVs are frequently isolated from domestic and wild birds throughout the world and are separated into nine serotypes (APMV-1 to -9. Only in the case of APMV-1, the infection of non-avian species has been investigated. The APMVs presently are being considered as human vaccine vectors. In this study, we evaluated the replication and pathogenicity of all nine APMV serotypes in hamsters. The hamsters were inoculated intranasally with each virus and monitored for clinical disease, pathology, histopathology, virus replication, and seroconversion. On the basis of one or more of these criteria, each of the APMV serotypes was found to replicate in hamsters. The APMVs produced mild or inapparent clinical signs in hamsters except for APMV-9, which produced moderate disease. Gross lesions were observed over the pulmonary surface of hamsters infected with APMV-2 & -3, which showed petechial and ecchymotic hemorrhages, respectively. Replication of all of the APMVs except APMV-5 was confirmed in the nasal turbinates and lungs, indicating a tropism for the respiratory tract. Histologically, the infection resulted in lung lesions consistent with bronchointerstitial pneumonia of varying severity and nasal turbinates with blunting or loss of cilia of the epithelium lining the nasal septa. The majority of APMV-infected hamsters exhibited transient histological lesions that self resolved by 14 days post infection (dpi. All of the hamsters infected with the APMVs produced serotype-specific HI or neutralizing antibodies, confirming virus replication. Taken together, these results demonstrate that all nine known APMV serotypes are capable of replicating in hamsters with minimal disease and pathology.

  12. The Chemistry of Cold: Mechanisms of Torpor Regulation in the Siberian Hamster.

    Science.gov (United States)

    Cubuk, Ceyda; Bank, Jonathan H H; Herwig, Annika

    2016-01-01

    Siberian hamsters use spontaneous daily torpor, a state of hypometabolism and hypothermia, to save energy during winter. Multiple neuroendocrine signals set the scene for spontaneous torpor to occur, and several brain areas have been identified as potential sites for torpor regulation. Here, we summarize the known mechanisms of a fascinating physiological state in the Siberian hamster. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

  13. Evaluation of the efficacy of a recombinant subunit West Nile vaccine in Syrian golden hamsters.

    Science.gov (United States)

    Siirin, Marina T; Travassos da Rosa, Amelia P A; Newman, Patrick; Weeks-Levy, Carolyn; Coller, Beth-Ann; Xiao, Shu-Yuan; Lieberman, Michael M; Watts, Douglas M

    2008-12-01

    The efficacy of a recombinant subunit West Nile (WN) vaccine candidate was determined in a hamster model of encephalitis. Animals included young, aged, and immunocompromised animals in an effort to simulate key groups at risk of WN virus-induced disease. Groups of aged (12 month old), weanling, and adult hamsters rendered leukopenic after immunization were immunized subcutaneously with a WN virus recombinant envelope protein (WN-80E) with or without WN virus non-structural protein 1 (NS1) mixed with adjuvant or adjuvant alone. A challenge dose of wild-type WN virus was administered to produce 40-100% mortality in the control hamsters. The recombinant antigen preparations containing WN-80E with or without WN NS1 gave similar results. Hamsters in both groups had a strong antibody response after immunization, and none of the aged or weanling animals became ill or developed detectable viremia after challenge with WN virus at 2 weeks after booster vaccination. However, mortality among the control animals (administered adjuvant without antigen) at 2 weeks after booster challenge was 40-60%. In hamsters rendered leukopenic after immunization, survival rates up to 80% were observed, and a low-level viremia was detected in the vaccinated and challenged hamsters. The survival rate was significantly (Psurvival after challenge. In contrast, all of the control animals that received adjuvant only developed a very high level of viremia, and the mortality rate was 100%. These findings indicate that the recombinant WN vaccines induced antibody in and afforded protection to young and aged hamsters and immunosuppressed hamsters.

  14. MS-8209, a new amphotericin B derivative, provides enhanced efficacy in delaying hamster scrapie.

    OpenAIRE

    Adjou, K T; Demaimay, R; Lasmezas, C; Deslys, J P; Seman, M; Dormont, D

    1995-01-01

    To test the efficacy of a new amphotericin B derivative, MS-8209, in delaying scrapie, hamsters were infected intracerebrally with the 263K scrapie agent and treated with MS-8209 either early in the course of the disease or continuously. The results show that (i) all treatments lengthened the incubation period of hamster scrapie, (ii) continuous treatment with MS-8209 doubled the length of the incubation period compared with that observed in infected, untreated animals, and (iii) all treatmen...

  15. Effects of tumor-promoting phorbol diesters on neoplastic progression of Syrian hamster embryo cells.

    Science.gov (United States)

    O'Brien, T G; Saladik, D; Diamond, L

    1982-04-01

    The progression of normal Syrian hamster embryo cells to a neoplastic phenotype after treatment with a chemical carcinogen and continuous exposure to phorbol ester tumor promoters was studied in cell culture. Tumor promoters were able to rescue cell lines derived from individual carcinogen-treated colonies from a program of cellular senescence. In general, these cell lines did not grow in soft-agar medium or produce tumors in newborn hamsters at early passages but acquired these properties at later passages. These cell lines were used to study the temporal acquisition of a phenotypic characteristic of neoplastic rather than normal hamster embryo cells: the synergistic induction of the enzyme ornithine decarboxylase (ODC) by tumor promoter and serum growth factors (O'Brien, T. G., Saladik, D., and Diamond, L. Regulation of polyamine biosynthesis in normal and transformed hamster cells in culture. Biochim. Biophys. Acta, 632: 270, 1980). All cell lines that acquired neoplastic status with passage in culture exhibited the synergistic induction of ODC prior to their acquisition of the ability to either grow in soft-agar medium or produce tumors in newborn hamsters. Cell lines that responded to promoters with the synergistic induction of ODC accumulated greater levels of polyamines, especially putrescine, after promoter treatment than did normal cells. Tumor promoters did not affect the percentage of cells labeled with [3H]thymidine in preneoplastic cell lines, a finding similar to previous results in normal and neoplastic hamster cells. These studies demonstrate that tumor promoters can affect the early stages of neoplastic progression in carcinogen-treated Syrian hamster embryo cells and that a particular phenotypic property found in neoplastic hamster cells, the synergistic induction of ODC by tumor promoters and serum growth factors, is acquired by cell lines before they acquire neoplastic potential.

  16. Cutaneous myxosarcoma in a Syrian hamster (Mesocricetus auratusMixossarcoma cutâneo em um Hamster Sírio

    Directory of Open Access Journals (Sweden)

    Renée Laufer Amorim

    2011-08-01

    Full Text Available The pathological findings in a 2-years-old Syrian hamster (Mesocricetus auratus with a cutaneous myxosarcoma are described. Grossly, there was a large cutaneous mass in the right cervical region. Microscopical evaluation revealed a myxosarcoma characterized by pleomorphic, fusiform cells loosely arranged, randomly distributed, and presenting a moderate amount of basophilic amorphous stroma. There were hemorrhagic areas within the tumor. The basophilic amorphous stroma was positive to Alcian blue confirming the presence of a mucopolysaccharide matrix. Immunohistochemically, the neoplastic cells expressed vimentin, and were negative for cytokeratin or glial fibrillary acidic protein (GFAP.São descritos os achados anatomopatológicos de um caso de mixossarcoma cutâneo em um Hamster Sírio de 2 anos de idade. Macroscopicamente, foi evidenciada um grande massa cutânea na região cervical lateral direita. A microscopia revelou a presença de um caso de mixossarcoma caracterizado por células fusiformes pleomórficas, frouxamente arranjadas, distribuídas aleatoriamente e, apresentando quantidade moderada de substância basofílica amorfa no estroma e áreas hemorrágicas. O estroma basofílico amorfo foi positivo na coloração Alcian blue, confirmando a presença de matriz mucopolissacarídea. Na imunoistoquímica, as células neoplásicas expressaram vimentina e foram negativas para a marcação de citoqueratina e proteína ácida fibrilar (GFAP.

  17. Autoradiographic localization of tritiated dihydrotestosterone in the flank organ of the albino hamster

    International Nuclear Information System (INIS)

    Lucky, A.W.; Eisenfeld, A.J.; Visintin, I.

    1985-01-01

    In the hamster flank organ, the growth of hair and growth of sebaceous glands are androgen-dependent functions. Although dihydrotestosterone (DHT) is known to be a potent stimulator of flank organ growth, there is no information about localization of DHT receptor sites in this organ. The purpose of this study was to use steroid autoradiography to localize DHT receptors in the hamster flank organ. Because steroid hormones are functional when translocated to nuclear receptors, nuclear localization by autoradiography defines receptor sites. In order to be able to visualize autoradiographic grains from radiolabeled androgens around hair follicles, albino hamsters were studied to avoid confusion between the grains and pigment granules which are abundant in the more common Golden Syrian hamster. Mature male hamsters castrated 24 hours earlier were given tritium-labeled dihydrotestosterone ( [ 3 H]DHT). Using the technique of thaw-mount steroid autoradiography, 4-micron unfixed frozen sections were mounted in the dark onto emulsion-coated glass slides and allowed to develop for 4-6 months. [ 3 H]DHT was found to be concentrated over sebocyte nuclei. The label was present peripherally as well as in differentiating sebocytes. There was no nuclear localization of [ 3 H]DHT in animals pretreated with excessive quantities of unlabeled DHT. Steroid metabolites of [ 3 H] DHT were assessed by thin-layer chromatography in paired tissue samples. Most of the label remained with DHT. Uptake was inhibited in the flank organ of hamsters pretreated with unlabeled DHT

  18. Circadian body temperature variability is an indicator of poor prognosis in cardiomyopathic hamsters.

    Science.gov (United States)

    Ahmed, Amany; Gondi, Sreedevi; Cox, Casey; Wang, Suwei; Stupin, Igor V; Shankar, K J; Munir, Shahzeb M; Sobash, Ed; Brewer, Alan; Ferguson, James J; Elayda, Macarthur A; Casscells, S Ward; Wilson, James M

    2010-03-01

    Low body temperature is an independent predictor of poor prognosis in patients with congestive heart failure. The cardiomyopathic hamster develops progressive biventricular dysfunction, resulting in heart failure death at 9 months to 1 year of life. Our goal was to use cardiomyopathic hamsters to examine the relationship between body temperature and heart failure decompensation and death. To this end, we implanted temperature and activity transducers with telemetry into the peritoneal space of 46 male Bio-TO-2 Syrian cardiomyopathic hamsters. Multiple techniques, including computing mean temperature, frequency domain analysis, and nonlinear analysis, were used to determine the most useful method for predicting poor prognosis. Data from 44 hamsters were included in our final analysis. We detected a decline in core body temperature in 98% of the hamsters 8+/-4 days before death (P temperature variation (ie, the circadian rhythm) by using cosinor analysis, which revealed a significant decrease in the amplitude of the body temperature circadian rhythm 8 weeks before death (0.28 degrees C; 95% CI, 0.26-0.31) compared to baseline (0.36 degrees C; 95% CI, 0.34-0.39; P=.005). The decline in the circadian temperature variation preceded all other evidence of decompensation. We conclude that a decrease in the amplitude of the body temperature circadian rhythm precedes fatal decompensation in cardiomyopathic hamsters. Continuous temperature monitoring may be useful in predicting preclinical decompensation in patients with heart failure and in identifying opportunities for therapeutic intervention. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  19. Divergent distribution of the sensor kinase CosS in non-thermotolerant campylobacter species and its functional incompatibility with the response regulator CosR of Campylobacter jejuni.

    Directory of Open Access Journals (Sweden)

    Sunyoung Hwang

    Full Text Available Two-component signal transduction systems are commonly composed of a sensor histidine kinase and a cognate response regulator, modulating gene expression in response to environmental changes through a phosphorylation-dependent process. CosR is an OmpR-type response regulator essential for the viability of Campylobacter jejuni, a major foodborne pathogenic species causing human gastroenteritis. Although CosR is a response regulator, its cognate sensor kinase has not been identified in C. jejuni. In this study, DNA sequence analysis of the cosR flanking regions revealed that a gene encoding a putative sensor kinase, which we named cosS, is prevalent in non-thermotolerant Campylobacter spp., but not in thermotolerant campylobacters. Phosphorylation assays indicated that C. fetus CosS rapidly autophosphorylates and then phosphorylates C. fetus CosR, suggesting that the CosRS system constitutes a paired two-component signal transduction system in C. fetus. However, C. fetus CosS does not phosphorylate C. jejuni CosR, suggesting that CosR may have different regulatory cascades between thermotolerant and non-thermotolerant Campylobacter species. Comparison of CosR homolog amino acid sequences showed that the conserved phosphorylation residue (D51, which is present in all non-thermotolerant Campylobacter spp., is absent from the CosR homologs of thermotolerant Campylobacter species. However, C. jejuni CosR was not phosphorylated by C. fetus CosS even after site-directed mutagenesis of N51D, implying that C. jejuni CosR may possibly function phosphorylation-independently. In addition, the results of cosS mutational analysis indicated that CosS is not associated with the temperature dependence of the Campylobacter spp. despite its unique divergent distribution only in non-thermotolerant campylobacters. The findings in this study strongly suggest that thermotolerant and non-thermotolerant Campylobacter spp. have different signal sensing mechanisms

  20. Evaluation of data from the literature on the transport and survival of Escherichia coli and thermotolerant coliforms in aquifers under saturated conditions.

    NARCIS (Netherlands)

    Foppen, J W A; Schijven, J F

    2006-01-01

    Escherichia coli and thermotolerant coliforms are of major importance as indicators of fecal contamination of water. Due to its negative surface charge and relatively low die-off or inactivation rate coefficient, E. coli is able to travel long distances underground and is therefore also a useful

  1. Toward an international standard for PCR-based detection of food-borne thermotolerant campylobacters: Validation in a multicenter collaborative trial

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Cook, N.; Wagner, M.

    2003-01-01

    As part of a European research project, the performance of a PCR assay to detect food-borne thermotolerant campylobacters (Campylobacter jejuni, C. coli, and C. lari) was evaluated through an international collaborative trial involving 12 participating laboratories. DNA from 10 target and 8...

  2. BODY WEIGHT AS A DETERMINANT OF CLINICAL EVOLUTION IN HAMSTERS (Mesocricetus auratus INFECTED WITH Leishmania (Viannia panamensis

    Directory of Open Access Journals (Sweden)

    Angela Maria Gomez-Galindo

    2013-09-01

    Full Text Available SUMMARY The clinical outcome of infection with Leishmania species of the subgenus Viannia in hamster model (Mesocricetus auratus has shown to be different depending on experimental protocol. Body weight has been a relevant determinant of the clinical outcome of the infection in hamsters with visceral leishmaniasis but its importance as a clinical parameter in hamsters with cutaneous leishmaniasis is not known. In this study, the clinical evolution of infection with L. (V panamensis was evaluated in juvenile and adult male hamsters during 11 weeks by comparing clinical parameters such as attitude, temperature, respiratory rate, appearance of the stool, and body weight between infected and non-infected groups. Results showed that body weight decreased in adult hamsters after infection by L. (V panamensis; this observation supports the use of body weight as an additional parameter to define the management or treatment of cutaneous leishmaniasis in infected adult hamsters used as an animal experimental model for leishmaniasis.

  3. [Expression of interferon alpha family gene of Chinese marmot in eukaryotic and prokaryotic cells].

    Science.gov (United States)

    Lu, Yin-ping; Wang, Bao-ju; Huang, Hong-ping; Tian, Yong-jun; Yang, Yan; Dong, Ji-hua; Lu, Meng-ji; Yang, Dong-liang

    2006-02-01

    To investigate the function of interferon alpha (IFNalpha) in a Chinese marmot model of hepatitis B, we expressed the Chinese marmot (Marmota himalayana) IFNalpha family gene (IFNA) in eukaryotic cells and prokaryotic cells. Eukaryotic and prokaryotic expression plasmids harboring Chinese marmot interferon alpha gene with different genotypes were generated using molecular cloning technology. We detected the biological activity of all expression products by viral protection assay, and analyzed their differences and species restriction of the biological activity. The Chinese marmot functional genotype IFNalpha was expressed in the baby hamster kidney (BHK) cell line, and these products protected WH12/6 cells challenged by encephalomyocarditis virus (EMCV). The Chinese marmot IFN-alpha5 also expressed in E. Coli induced by IPTG, and purified fusion protein had antiviral biological activity. The biologic activity displayed differences among different subtype IFNalpha, and it had strict species restriction. The IFNalpha family gene of the Chinese marmot can be expressed in both eukaryotic and prokaryotic cells, and the expression products show antiviral activity in a protection assay. This study provides, for the first time, evidence that IFNalpha from the Chinese marmot has an antiviral function in vitro and can be used to improve the efficacy of current therapies for HBV infection in our Chinese marmot model.

  4. Chinese restaurant syndrome

    Science.gov (United States)

    Chinese restaurant syndrome is a set of symptoms that some people have after eating Chinese food. A food additive ... Chinese restaurant syndrome is most often diagnosed based on the symptoms. The health care provider may ask the following ...

  5. Syrian Hamster as an Animal Model for the Study of Human Influenza Virus Infection.

    Science.gov (United States)

    Iwatsuki-Horimoto, Kiyoko; Nakajima, Noriko; Ichiko, Yurie; Sakai-Tagawa, Yuko; Noda, Takeshi; Hasegawa, Hideki; Kawaoka, Yoshihiro

    2018-02-15

    Ferrets and mice are frequently used as animal models for influenza research. However, ferrets are demanding in terms of housing space and handling, whereas mice are not naturally susceptible to infection with human influenza A or B viruses. Therefore, prior adaptation of human viruses is required for their use in mice. In addition, there are no mouse-adapted variants of the recent H3N2 viruses, because these viruses do not replicate well in mice. In this study, we investigated the susceptibility of Syrian hamsters to influenza viruses with a view to using the hamster model as an alternative to the mouse model. We found that hamsters are sensitive to influenza viruses, including the recent H3N2 viruses, without adaptation. Although the hamsters did not show weight loss or clinical signs of H3N2 virus infection, we observed pathogenic effects in the respiratory tracts of the infected animals. All of the H3N2 viruses tested replicated in the respiratory organs of the hamsters, and some of them were detected in the nasal washes of infected animals. Moreover, a 2009 pandemic (pdm09) virus and a seasonal H1N1 virus, as well as one of the two H3N2 viruses, but not a type B virus, were transmissible by the airborne route in these hamsters. Hamsters thus have the potential to be a small-animal model for the study of influenza virus infection, including studies of the pathogenicity of H3N2 viruses and other strains, as well as for use in H1N1 virus transmission studies. IMPORTANCE We found that Syrian hamsters are susceptible to human influenza viruses, including the recent H3N2 viruses, without adaptation. We also found that a pdm09 virus and a seasonal H1N1 virus, as well as one of the H3N2 viruses, but not a type B virus tested, are transmitted by the airborne route in these hamsters. Syrian hamsters thus have the potential to be used as a small-animal model for the study of human influenza viruses. Copyright © 2018 American Society for Microbiology.

  6. A lethal disease model for hantavirus pulmonary syndrome in immunosuppressed Syrian hamsters infected with Sin Nombre virus.

    Science.gov (United States)

    Brocato, Rebecca L; Hammerbeck, Christopher D; Bell, Todd M; Wells, Jay B; Queen, Laurie A; Hooper, Jay W

    2014-01-01

    Sin Nombre virus (SNV) is a rodent-borne hantavirus that causes hantavirus pulmonary syndrome (HPS) predominantly in North America. SNV infection of immunocompetent hamsters results in an asymptomatic infection; the only lethal disease model for a pathogenic hantavirus is Andes virus (ANDV) infection of Syrian hamsters. Efforts to create a lethal SNV disease model in hamsters by repeatedly passaging virus through the hamster have demonstrated increased dissemination of the virus but no signs of disease. In this study, we demonstrate that immunosuppression of hamsters through the administration of a combination of dexamethasone and cyclophosphamide, followed by infection with SNV, results in a vascular leak syndrome that accurately mimics both HPS disease in humans and ANDV infection of hamsters. Immunosuppressed hamsters infected with SNV have a mean number of days to death of 13 and display clinical signs associated with HPS, including pulmonary edema. Viral antigen was widely detectable throughout the pulmonary endothelium. Histologic analysis of lung sections showed marked inflammation and edema within the alveolar septa of SNV-infected hamsters, results which are similar to what is exhibited by hamsters infected with ANDV. Importantly, SNV-specific neutralizing polyclonal antibody administered 5 days after SNV infection conferred significant protection against disease. This experiment not only demonstrated that the disease was caused by SNV, it also demonstrated the utility of this animal model for testing candidate medical countermeasures. This is the first report of lethal disease caused by SNV in an adult small-animal model.

  7. Synthesis of human prolactin in Chinese hamster ovary (CHO) cells; Sintese de prolactina humana em celulas de ovario de hamster chines (CHO)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Roberto Jorge

    2000-07-01

    Three different eukaryotic expression vectors, based on the same selectable gene marker (dhfr), have been used for dhf- CHO cells transfection to rapidly isolate stable cell lines capable of secreting high levels of recombinant human prolactin (rec-hPRL). Two vectors, one codifying a human prolactin (p658-hPRL) and the other a tag-prolactin (p658-tagPRL), contain the complete hepatitis B virus-X (HBV-X) gene coding for a viral transactivator and a sequence derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF) that mediates selective dhfr mRNA degradation. These vectors have the advantage of rapidly obtaining stable cell lines without methotrexate amplification. The highest secretion obtained by these vectors was of approximately 10 {mu}g hPRU10{sup 6} cells/day. The other vector (pEDdc-hPRL) is based on a dicistronic expression system, containing an internal ribosome entry site isolated from the encephalomyocarditis (EMC) virus. This vector before amplification provided secretion levels at least 10 fold lower than that obtained with the other two vectors. However, after three steps of methotrexate amplification, it provided some clones able to secrete up to 30 {mu}g hPRU10{sup 6} cells/day. This is the first report describing the production and purification of rec-hPRL from CHO cells, obtaining secretion levels with both vectors higher than those reported so far for this hormone in other eukaryotic systems. CHO-derived rec-hPRL contained approximately 10 % of the glycosylated form, a value that is consistent with results reported for hPRL purified from the pituitary or from transformed murine C-127 cells. CHO-derived rec-hPRL was purified with good yield, obtaining also a good resolution between non-glycosylated and glycosylated prolactin. The latter, when its potency was determined via an in vitro bioassay, presented a 47 % lower bioactivity. A qualitative and quantitative analysis of these forms was also possible thanks to the setting up of a reversed-phase HPLC technique, for the first time applied to this hormone. A pilot production in a hollow fiber bioreactor provided a highly concentrated medium, though with the presence of considerable amounts of hPRL{sub 11-199} fragments, apparently the result of a proteolytic process. (author)

  8. Transmission of chronic wasting disease identifies a prion strain causing cachexia and heart infection in hamsters.

    Directory of Open Access Journals (Sweden)

    Richard A Bessen

    Full Text Available Chronic wasting disease (CWD is an emerging prion disease of free-ranging and captive cervids in North America. In this study we established a rodent model for CWD in Syrian golden hamsters that resemble key features of the disease in cervids including cachexia and infection of cardiac muscle. Following one to three serial passages of CWD from white-tailed deer into transgenic mice expressing the hamster prion protein gene, CWD was subsequently passaged into Syrian golden hamsters. In one passage line there were preclinical changes in locomotor activity and a loss of body mass prior to onset of subtle neurological symptoms around 340 days. The clinical symptoms included a prominent wasting disease, similar to cachexia, with a prolonged duration. Other features of CWD in hamsters that were similar to cervid CWD included the brain distribution of the disease-specific isoform of the prion protein, PrP(Sc, prion infection of the central and peripheral neuroendocrine system, and PrP(Sc deposition in cardiac muscle. There was also prominent PrP(Sc deposition in the nasal mucosa on the edge of the olfactory sensory epithelium with the lumen of the nasal airway that could have implications for CWD shedding into nasal secretions and disease transmission. Since the mechanism of wasting disease in prion diseases is unknown this hamster CWD model could provide a means to investigate the physiological basis of cachexia, which we propose is due to a prion-induced endocrinopathy. This prion disease phenotype has not been described in hamsters and we designate it as the 'wasting' or WST strain of hamster CWD.

  9. DEVELOPMENT OF MICE AND HAMSTER EMBRYOS IN KSOMAA AND HECM-6 MEDIUM

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    Bayu Rosadi

    2008-12-01

    Full Text Available The purpose of the present study was to investigate the viability of mice and hamster embryos developed in Kalium Simplex Optimized Medium amino acid (KSOMaa and Hamster Embryo Culture Medium-6 (HECM-6 medium. Female DDY mice were superovulated by injection i.p. of 5 IU Pregnant Mare Serum Gonadotropine (PMSG and 5 IU Human Chorionic Gonadotropine (hCG in 48 h interval, hamster (Phodopus campbelli injected by 2.5 IU PMSG and 2.5 IU hCG 48 h later. Then females were mated with fertile males. Eight-cell embryos were recovered at day 3 after natural mating. The mice embryos were cultured in KSOMaa+5% NBCS (New Born Calf Serum (T1 and HECM-6+5% NBCS (T2, the hamster embryos were cultured in KSOMaa+5% NBCS (T3 and HECM-6 + 5% NBCS (T4 for further development at 37oC in a humidified atmosphere of 5% CO2 in air for 48 h. The examinations were replicated five times. The T1 embryos developed to compact morulla and early blastocyst 100% (140/140, 92.1% (129/140 to blastocyst and expanded blastocyst, and 22.9% (32/140 became hatching/hatched. The T3 reached 100% (60/60 to compact morulla and early blastocyst, 85.0% (51/60 blastocyst, and 48.3% (29/60 expanded blastocyst, no embryo observed hatching/hatced. The T2 embryos had more expanded blastocyst than T3 (P<0.05, hatching/hatched rate higher than T1 and T3 but lower than T4 (P<0.05. Shortly, KSOMaa enable to support 8-cell stage mice and hamster embryo, but the hamster embryo developed lower at expanded blastocyst stage. HECM-6 is more appropriate than KSOMaa to support 8-cell mice embryos development and suitable to develop 8-cell stage hamster embryos.

  10. Search for rhythmicity during hibernation in the European hamster.

    Science.gov (United States)

    Canguilhem, B; Malan, A; Masson-Pévet, M; Nobelis, P; Kirsch, R; Pévet, P; Le Minor, J

    1994-01-01

    Temporal patterns of hibernation were studied by continuous monitoring of body temperature by radiotelemetry over 6 months in European hamsters, Cricetus cricetus, at constant temperature and photoperiod. Entrances into hibernation occurred mostly at the end of the night (0000-0800 hours), while arousals were randomly distributed between day and night. This is at variance with a control of bout duration by a clock with a period of 24 h. Consequently, the timing of entrances implies a phase-resetting of the circadian clock on each arousal. Persistence of circadian rhythmicity with a period different from 24 h during deep hibernation was investigated examining whether the durations of torpor bouts were integer multiples of a constant period. A non-parametric version of the classical contingency test of periodicity was developed for this purpose. Periods ranging from 21 to 29 h were tested. Nine animals out of ten showed at least one significant period in this range (P < 0.01), either below 24 h (21.8 +/- 0.5 h, n = 4) or above (27.3 +/- 0.5 h, n = 7). However, we have found a theoretical model of bout durations for which the contingency test of periodicity sometimes gives false significant results. This indicates that the power of the test is weak. With this reservation our results suggest that a circadian oscillator controls the duration of a bout of hibernation, which would occur after an integer, but variable and possibly temperature-dependent number of cycles.

  11. Obesity induction in hamster that mimics the human clinical condition.

    Science.gov (United States)

    Jordania da Silva, Vivian; Dias, Sílvia Regina Costa; Maioli, Tatiani Uceli; Serafim, Luciana Ribeiro; Furtado, Luis Fernando Viana; Quintão Silva, Maria da Gloria; Faria, Ana Maria Caetano de; Rabelo, Élida Mara Leite

    2017-08-05

    Although obesity is well established in hamsters, studies using diets with high levels of simple carbohydrate associated with lipids are necessary to assess the impact of this type of food in the body. In this study a high sugar and butter diet (HSB) and high temperature were employed towards this end. Obesity was successfully induced at a temperature of 30.3°C to 30.9°C after 38 days feeding the animals an HSB diet. It was shown that although diet is important for the induction of obesity, temperature is also essential because at a temperature slightly below the one required, obesity was not induced, even when the animals were fed for a longer period (150 days).The obese clinical condition was accompanied by biochemical and hematological changes, as increased cholesterol and triglyceride levels and increased leukocyte numbers, similar to alterations observed in obese humans. Furthermore, it was demonstrated that increasing the intake of simple carbohydrates associated with lipids provided evidence of inflammation in obese animals.

  12. Investigation of estrogen receptor functionality in hamster melanoma

    International Nuclear Information System (INIS)

    Hitselberger, M.H.

    1987-01-01

    The biology of hamster melanoma, HM1, was assessed congenitally athymic mice after administration of estradiol. Chronic treatment with this steroid hormone delayed tumor appearance in females, inhibited tumor growth in both sexes and reduced the number of lung metastatic lesions in males. Cytosol and nuclear estrogen receptors were characterized in HM1 cells. Specific binding in both fractions was saturable and indicative of high affinity sites with a mean Kd of 0.22 nM in the cytosol and 1.5 nM in the nucleus. Sucrose density-gradient centrifugation of 3 H-estradiol-labelled cytosol demonstrated a peak in the 8S-9S region, which was completely suppressible by excess diethylstilbesterol. To determine whether the estrogen receptor in HM1 cells was functional, athymic mice received 2.5 μg estradiol or vehicle s.c. and were necroscopied 1, 2, 6 and 24 hr later. Nuclear estrogen receptor content was maximal one hr after injection of estradiol and declined to control levels by 24 hr. This effect was accompanied by a rapid reduction in cytosol estrogen receptor content which returned to control levels by 24 hr. A physiologic dose of estradiol, 0.1 μg, injected one hr prior to necroscopy, produced maximal changes in cytosol and nuclear estrogen receptor content

  13. Social housing and social isolation: Impact on stress indices and energy balance in male and female Syrian hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Ross, Amy P; Norvelle, Alisa; Choi, Dennis C; Walton, James C; Albers, H Elliott; Huhman, Kim L

    2017-08-01

    Although Syrian hamsters are thought to be naturally solitary, recent evidence from our laboratory demonstrates that hamsters may actually prefer social contact. Hamsters increase their preference for a location associated with an agonistic encounter regardless of whether they have "won" or "lost". It has also been reported that social housing as well as exposure to intermittent social defeat or to a brief footshock stressor increase food intake and body mass in hamsters. By contrast, it has also been suggested that housing hamsters in social isolation causes anxiety-induced anorexia and reductions in body mass selectively in females. The purpose of this study was to determine the physiological consequences of housing hamsters in social isolation versus in social groups. Male and female hamsters were housed singly or in stable groups of 5 for 4weeks after which they were weighed and trunk blood was collected. In addition, fat pads and thymus and adrenal glands were extracted and weighed. Serum and fecal cortisol were measured using an enzyme-linked immunoassay. Housing condition had no effect on serum or fecal cortisol, but socially housed hamsters displayed modest thymus gland involution. Socially housed females weighed more than did any other group, and socially housed females and males had more fat than did socially isolated hamsters. No wounding or tissue damage occurred in grouped hamsters. Overall, these data suggest that Syrian hamsters tolerate both stable social housing and social isolation in the laboratory although social housing is associated with some alteration in stress-related and bioenergetic measures. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Effect of lignocellulosic inhibitory compounds on growth and ethanol fermentation of newly-isolated thermotolerant Issatchenkia orientalis.

    Science.gov (United States)

    Kwon, Yong-Jin; Ma, An-Zhou; Li, Qian; Wang, Feng; Zhuang, Guo-Qiang; Liu, Chun-Zhao

    2011-09-01

    A newly isolated thermotolerant ethanologenic yeast strain, Issatchenkia orientalis IPE 100, was able to produce ethanol with a theoretical yield of 85% per g of glucose at 42°C. Ethanol production was inhibited by furfural, hydroxymethylfurfural and vanillin concentrations above 5.56 gL(-1), 7.81 gL(-1), and 3.17 gL(-1), respectively, but the strain was able to produce ethanol from enzymatically hydrolyzed steam-exploded cornstalk with 93.8% of theoretical yield and 0.91 gL(-1)h(-1) of productivity at 42°C. Therefore, I. orientalis IPE 100 is a potential candidate for commercial lignocelluloses-to-ethanol production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Ethanol fermentation by the thermotolerant yeast, Kluyveromyces marxianus TISTR5925, of extracted sap from old oil palm trunk

    Directory of Open Access Journals (Sweden)

    Yoshinori Murata

    2015-05-01

    Full Text Available Palm sap extracted from old oil palm trunks was previously found to contain sugar and nutrients (amino acids and vitamins. Some palm saps contain a low content of sugar due to differences in species or in plant physiology. Here we condensed palm sap with a low content of sugar using flat membrane filtration, then fermented the condensed palm sap at high temperature using the thermotolerant, high ethanol-producing yeast, Kluyveromyces marxianus. Ethanol production under non-optimum conditions was evaluated. Furthermore, the energy required to concentrate the palm sap, and the amount of energy that could be generated from the ethanol, was calculated. The condensation of sugar in sap from palm trunk required for economically viable ethanol production was evaluated.

  16. Adenovirus, enterovirus and thermotolerant coliforms in recreational waters from Lake Guaíba beaches, Porto Alegre, Brazil.

    Science.gov (United States)

    Maurer, C P; Simonetti, A B; Staggemeier, R; Rigotto, C; Heinzelmann, L S; Spilki, F R

    2015-12-01

    In the present study, molecular detection of human adenoviruses (HAdV) and enteroviruses (EV) was performed in surface water samples collected from beaches Ipanema and Lami, located on the shores of Lake Guaíba, city of Porto Alegre, RS, southern Brazil. Furthermore, water safety was evaluated by counting thermotolerant coliforms (TC), following local government regulations. A total of 36 samples were collected monthly from six different sites along the beaches. Viral genomes were found in 30 (83.3%) samples. The higher detection rate was observed for HAdV (77.8%), followed by EV (22.2%). Although low concentrations of TC have been found, the occurrence of viral genomes in water samples was frequent and may pose a potential risk of infection for people bathing in these beaches.

  17. Central nervous system promotes thermotolerance via FoxO/DAF-16 activation through octopamine and acetylcholine signaling in Caenorhabditis elegans.

    Science.gov (United States)

    Furuhashi, Tsubasa; Sakamoto, Kazuichi

    2016-03-25

    The autonomic nervous system (ANS) responds to many kinds of stressors to maintain homeostasis. Although the ANS is believed to regulate stress tolerance, the exact mechanism underlying this is not well understood. To understand this, we focused on longevity genes, which have functions such as lifespan extension and promotion of stress tolerance. To understand the relationship between ANS and longevity genes, we analyzed stress tolerance of Caenorhabditis elegans treated with octopamine, which has an affinity to noradrenaline in insects, and acetylcholine. Octopamine and acetylcholine did not show resistance against H2O2, but the neurotransmitters promoted thermotolerance via DAF-16. However, chronic treatment with octopamine and acetylcholine did not extend the lifespan, although DAF-16 plays an important role in longevity. In conclusion, our results show that octopamine and acetylcholine activate DAF-16 in response to stress, but chronic induction of octopamine and acetylcholine is not beneficial for increasing longevity. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Sulfuric acid hydrolysis and detoxification of red alga Pterocladiella capillacea for bioethanol fermentation with thermotolerant yeast Kluyveromyces marxianus.

    Science.gov (United States)

    Wu, Chien-Hui; Chien, Wei-Chen; Chou, Han-Kai; Yang, Jungwoo; Lin, Hong-Ting Victor

    2014-09-01

    One-step sulfuric acid saccharification of the red alga Pterocladiella capillacea was optimized, and various detoxification methods (neutralization, overliming, and electrodialysis) of the acid hydrolysate were evaluated for fermentation with the thermotolerant yeast Kluyveromyces marxianus. A proximate composition analysis indicated that P. capillacea was rich in carbohydrates. A significant galactose recovery of 81.1 ± 5% was also achieved under the conditions of a 12% (w/v) biomass load, 5% (v/v) sulfuric acid, 121°C, and hydrolysis for 30 min. Among the various detoxification methods, electrodialysis was identified as the most suitable for fermentable sugar recovery and organic acid removal (100% reduction of formic and levulinic acids), even though it failed to reduce the amount of the inhibitor 5-HMF. As a result, K. marxianus fermentation with the electrodialyzed acid hydrolysate of P. capillacea resulted in the best ethanol levels and fermentation efficiency.

  19. Effect of dietary fatty acids on metabolic rate and nonshivering thermogenesis in golden hamsters.

    Science.gov (United States)

    Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-02-01

    Hibernating rodents prior to winter tend to select food rich in polyunsaturated fatty acids (PUFA). Several studies found that such diet may positively affect their winter energy budget by enhancing torpor episodes. However, the effect of composition of dietary fatty acids (FA) on metabolism of normothermic heterotherms is poorly understood. Thus we tested whether diets different in FA composition affect metabolic rate (MR) and the capacity for nonshivering thermogenesis (NST) in normothermic golden hamsters (Mesocricetus auratus). Animals were housed in outdoor enclosures from May 2010 to April 2011 and fed a diet enriched with PUFA (i.e., standard food supplemented weekly with sunflower and flax seeds) or with saturated and monounsaturated fatty acids (SFA/MUFA, standard food supplemented with mealworms). Since diet rich in PUFA results in lower MR in hibernating animals, we predicted that PUFA-rich diet would have similar effect on MR of normothermic hamsters, that is, normothermic hamsters on the PUFA diet would have lower metabolic rate in cold and higher NST capacity than hamsters supplemented with SFA/MUFA. Indeed, in winter resting metabolic rate (RMR) below the lower critical temperature was higher and NST capacity was lower in SFA/MUFA-supplemented animals than in PUFA-supplemented ones. These results suggest that the increased capacity for NST in PUFA-supplemented hamsters enables them lower RMR below the lower critical temperature of the thermoneural zone. © 2013 Wiley Periodicals, Inc.

  20. The effect of dietary vitamin A on NO2 exposure on the hamster lung

    International Nuclear Information System (INIS)

    Kim, J.C.

    1978-01-01

    The effect of dietary vitamin A and NO2 exposure on the hamster lung was evaluated by histopathology, electron microscopy, and thymidine uptake studies. Hamsters were maintained on deficient (0 micrograms), adequate (100 micrograms), and high (200 micrograms) dose levels of vitamin A while being exposed repeatedly to 10 ppm of NO2 for 5 hours once a week over an 8-week period. Hamsters of the deficient group exhibited clinical and morphologic changes characteristic of vitamin A deficiency. Animals maintained on adequate and high dose levels of vitamin A were not affected by vitamin A deficiency. Hypertrophy and hyperplasia of the epithelial cells of the terminal bronchiolar alveolar region of lungs of adequately and highly dosed animals were greater than those observed in the deficient animals, when NO2 exposure was given. However, the extent of the lesions observed in all three groups was less than that seen in normal hamsters given a single, 5-hour NO2 exposure. Ultrastructural changes observed in vitamin A-deficient hamsters exposed to NO2 were hypertrophy and hyperplasia of bronchiolar epithelial cells, diffuse loss of cilia, membrane damage, and mitochondrial damage manifested by calcium deposition. Tritiated thymidine uptake studies of lungs of animals exposed repeatedly revealed a rather erratic cell renewal pattern following NO2 exposure in comparison to the group of animals exposed singly