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Sample records for chinese hamster fibroblasts

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  3. Transfection of normal human and Chinese hamster DNA corrects diepoxybutane-induced chromosomal hypersensitivity of Fanconi anemia fibroblasts

    International Nuclear Information System (INIS)

    Cultured cells from individuals affected with Fanconi anemia (FA) exhibit spontaneous chromosome breakage and hypersensitivity to the cell killing and clastogenic effects of the difunctional alkylating agent diepoxybutane (DEB). The authors report here the correction of both of these DEB-hypersensitivity phenotypes of FA cells achieved by cotransfection of normal placental of Chinese hamster lung cell DNA and the plasmid pSV2-neo-SVgpt. Transfectants were selected for clonogenic survival after treatment with DEB at a dose of 5 μgml. At this dose of DEB, the clonogenicity of normal fibroblasts was reduced to 50% and that of FA fibroblasts was reduced to zero. DEB-resistant (DEB/sup r/) colonies selected in this system exhibited a normal response to DEB-induced chromosome breakage and resistance to repeated DEB treatment. The neo and gpt sequences were detected by Southern blot analysis of DNA from one of four DEB/sup r/ colonies independently derived from transfection of human DNA and one of three DEB/sup r/ colonies independently derived from transfection of Chinese hamster DNA. The results demonstrate that DNA sequences that complement the two hallmark cellular phenotypes (cellular and chromosomal hypersensitivity to alkylating agents) of FA are present in human as well as Chinese hamster DNA. The cloning of these genes using transfection strategies can be expected to enable molecular characterization of FA

  4. Modification of radiation damages of chromosomes of Chinese hamster fibroblasts in a cell culture

    International Nuclear Information System (INIS)

    Influence of caffeine sodium benzoate (0.8 to 8.0 mM) on the yield of chromosome aberrations in Chinese hamster cells irradiated at G2 and S stages has been studied. To estimate the modifying effect correctly a caffeine-induced deceleration of the cell cycle as well as the effect of caffeine on the radiation delay of fission were registered. The increase in the damage was most pronounced at the stage of the DNA synthesis; variations in the yield of aberrations were smooothed away considerably, under the effect of caffeine, in the course of G2 and S stages. This indicates that the changes in the yield of chromosome aberrations within the cycle were mainly due to different degree of repair at different stages rather than to varying number of primary potential damages

  5. 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)

    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

  6. Protective effect of enzymatic hydrolysates from highbush blueberry (Vaccinium corymbosum L.) against hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast cell line

    OpenAIRE

    Senevirathne, Mahinda; Kim, Soo-Hyun; Jeon, You-Jin

    2010-01-01

    Blueberry was enzymatically hydrolyzed using selected commercial food grade carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to obtain water soluble compounds, and their protective effect was investigated against H2O2-induced damage in Chinese hamster lung fibroblast cell line (V79-4) via various published methods. Both AMG and Alcalase hydrolysates showed higher total phenolic content as well as higher ce...

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

    International Nuclear Information System (INIS)

    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

  8. Protective Effect of Boric Acid on Oxidative DNA Damage In Chinese Hamster Lung Fibroblast V79 Cell Lines

    Directory of Open Access Journals (Sweden)

    SezenYılmaz

    2016-02-01

    Full Text Available Objective: Many studies have been published on the antioxidative effects of boric acid (BA and sodium borates in in vitro studies. However, the boron (B concentrations tested in these in vitro studies have not been selected by taking into account the realistic blood B concentrations in humans due to the lack of comprehensive epidemiological studies. The recently published epidemiological studies on B exposure conducted in China and Turkey provided blood B concentrations for both humans in daily life and workers under extreme exposure conditions in occupational setting. The results of these studies have made it possible to test antioxidative effects of BA in in vitro studies within the concentration range relevant to humans. The aim of this study was to investigate the protective effects of BA against oxidative DNA damage in V79 (Chinese hamster lung fibroblast cells. The concentrations of BA tested for its protective effect was selected by taking the blood B concentrations into account reported in previously published epidemiological studies. Therefore, the concentrations of BA tested in this study represent the exposure levels for humans in both daily life and occupational settings. Materials and Methods: In this experimental study, comet assay and neutral red uptake (NRU assay methods were used to determinacy to toxicity and genotoxicity of BA and hydrogen peroxide (H2O2. Results: The results of the NRU assay showed that BA was not cytotoxic within the tested concentrations (3, 10, 30, 100 and 200 μM. These non-cytotoxic concentrations were used for comet assay. BA pre-treatment significantly reduced (P<0.05, one-way ANOVA the DNA damaging capacity of H2O2 at each tested BA concentrations in V79 cells. Conclusion: Consequently, pre-incubation of V79 cells with BA has significantly reduced the H2O2-induced oxidative DNA damage in V79 cells. The protective effect of BA against oxidative DNA damage in V79 cells at 5, 10, 50, 100 and 200 μM (54

  9. 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)

    Induction of chromatid aberrations in S-phase Chinese hamster fibroblasts has been studied for irradiation by 60Co 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)

  10. Track segment studies with Chinese hamster cells

    International Nuclear Information System (INIS)

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

  11. 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)

    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

  12. 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 for...

  13. Proteomic Analysis of Chinese Hamster Ovary Cells

    DEFF Research Database (Denmark)

    Baycin-Hizal, Deniz; Tabb, David L.; Chaerkady, Raghothama; Chen, Lily; Lewis, Nathan; Nagarajan, Harish; Sarkaria, Vishaldeep; Kumar, Amit; Wolozny, Daniel; Colao, Joe; Jacobson, Elena; Tian, Yuan; O’Meally, Robert N.; Krag, Sharon S.; Cole, Robert N.; Palsson, Bernhard; Zhang, Hui; Betenbaugh, Michael

    2012-01-01

    this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis......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...... identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using the CHO genome exclusively, which provides for more accurate identification of proteins. From...

  14. Proteomic analysis of Chinese hamster ovary cells.

    Science.gov (United States)

    Baycin-Hizal, Deniz; Tabb, David L; Chaerkady, Raghothama; Chen, Lily; Lewis, Nathan E; Nagarajan, Harish; Sarkaria, Vishaldeep; Kumar, Amit; Wolozny, Daniel; Colao, Joe; Jacobson, Elena; Tian, Yuan; O'Meally, Robert N; Krag, Sharon S; Cole, Robert N; Palsson, Bernhard O; Zhang, Hui; Betenbaugh, Michael

    2012-11-01

    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, multidimensional liquid chromatography, and solid phase extraction of glycopeptides (SPEG). From the 120 different mass spectrometry analyses generating 682,097 MS/MS spectra, 93,548 unique peptide sequences were identified with at most 0.02 false discovery rate (FDR). A total of 6164 grouped proteins were identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using the CHO genome exclusively, which provides for more accurate identification of proteins. From this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis but depletion of proteins involved in steroid hormone and glycosphingolipid metabolism. Five-hundred four of the detected proteins included N-acetylation modifications, and 1292 different proteins were observed to be N-glycosylated. This first large-scale proteomic analysis will enhance the knowledge base about CHO capabilities for recombinant expression and provide information useful in cell engineering efforts aimed at modifying CHO cellular functions. PMID:22971049

  15. Chinese hamster ovary cell lysosomes retain pinocytized horseradish peroxidase and in situ-radioiodinated proteins

    International Nuclear Information System (INIS)

    We used Chinese hamster ovary cells, a cell line of fibroblastic origin, to investigate whether lysosomes are an exocytic compartment. To label lysosomal contents, Chinese hamster ovary cells were incubated with the solute marker horseradish peroxidase. After an 18-h uptake period, horseradish peroxidase was found in lysosomes by cell fractionation in Percoll gradients and by electron microscope cytochemistry. Over a 24-h period, lysosomal horseradish peroxidase was quantitatively retained by Chinese hamster ovary cells and inactivated with a t 1/2 of 6 to 8 h. Lysosomes were radioiodinated in situ by soluble lactoperoxidase internalized over an 18-h uptake period. About 70% of the radioiodine incorporation was pelleted at 100,000 X g under conditions in which greater than 80% of the lysosomal marker enzyme beta-hexosaminidase was released into the supernatant. By one-dimensional electrophoresis, about 18 protein species were present in the lysosomal membrane fraction, with radioiodine incorporation being most pronounced into species of 70,000 to 75,000 daltons. After a 30-min or 2-h chase at 37 degrees C, radioiodine that was incorporated into lysosomal membranes and contents was retained in lysosomes. These observations indicate that lysosomes labeled by fluid-phase pinocytosis are a terminal component of endocytic pathways in fibroblasts

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

    International Nuclear Information System (INIS)

    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)

  17. Kinetic differences between fed and starved Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    When Chinese hamster ovary (CHO) cells are grown as monolayer cultures, they eventually reach a population-density plateau after which no net increase in cell numbers occurs. A manuscript has recently been published which draws attention to the important, and perhaps unexpected, differences in the kinetic status of different types of plateau-phase CHO cells (Nelson, Todd and Metting 1984). The essence of this manuscript and the most significant findings are summarized in this paper

  18. X-ray epilation and hair detriments in chinese hamsters

    International Nuclear Information System (INIS)

    Chinese hamsters were exposed to an acute dose of whole-body x radiation. Survivors displayed a wave-like pattern of epilation and hair-graying that has not previously been reported in the literature. The pigment score, length, and width of individual graying hairs from the haunch and shoulder of the surviving animals were statistically analyzed to demonstrate x radiation damage to and recovery of the follicle and pigment cells

  19. Transfer of human genes conferring resistance to methylating mutagens, but not to UV irradiation and cross-linking agents, into Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Chinese hamster ovary cells were transfected by human DNA ligated to the bacterial gpt (xanthine-guanine-phosphoribosyltransferase) gene which was used either in its native form or after partial inactivation with methylnitrosourea. The gpt+ transfectants were screened for resistance to high doses of N-methyl-N'-nitro-N-nitrosoguanidine. Using this approach, we showed that Chinese hamster ovary cells can acquire N-methyl-N'-nitro-N-nitrosoguanidine resistance upon transfection with DNA from diploid human fibroblasts, that this resistance is transferable by secondary transfection and is specific for methylating mutagens, and that it is not caused by increased removal of O6-methylguanine, 3-methyladenine, and 7-methylguanine from DNA

  20. Stereoconfiguration of bisphosphatidic and semilysobisphosphatidic acids from cultured hamster fibroblasts (BHK cells).

    Science.gov (United States)

    Somerharju, P; Brotherus, J; Kahma, K; Renkonen, O

    1977-04-26

    Monolayers of hamster fibroblasts (BHK cells) were incubated in Eagle's minimal essential medium under conditions where an increase in the levels of all cellular bisphosphatidic acids takes place. Bisphosphatidic acid and semilysobisphosphatidic were isolated from these cells and subjected to strong alkaline hydrolysis. Stereochemical analysis of the hydrolysis products revealed that the majority of the molecules of both lipids are derivatives of sn-1-glycerophospho-sn-1'-glycerol, the structure previously found to be the "backbone" of lysobisphosphatidic acid, (bis(monoacylglycerol)phosphate) from BHK cells and other sources. This finding suggests a close metabolic relationship between the three bisphosphatidic acid derivatives of BHK cells. PMID:857898

  1. Photosensitized inactivation of Chinese hamster cells by phthalocyanines

    International Nuclear Information System (INIS)

    Chloroaluminum phthalocyanine was found to sensitize cultured Chinese hamster cells upon exposure to white fluorescent light. Elimination of wavelengths below 370 nm did not reduce the effect significantly, indicating that the effective wavelengths were those absorbed by the Q band (600-700 nm) of phthalocyanine. The magnitude of the photosensitizing effect increased with the dye concentration and the time of its contact with the cells prior to light exposure. Although photosensitization was drastically reduced in the absence of oxygen, the lack of effect of glycerol and D2O during exposure suggests that neither hydroxyl radicals nor 1O2 are responsible for the cytotoxic response. The efficiency of the photosensitized induced cell killing did not vary with the position of the cells in the cell cycle, in contrast to exposure to X-rays. The improved spectral properties, the reported low toxicity and the selective retention by neoplasms, make phthalocyanines promising candidates for use in photodynamic therapy of cancer. (author)

  2. Refeeding alters superoxide dismutase activity in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The authors previously showed superoxide dismutase (SOD) activity is increased in heat shocked Chinese hamster ovary (CHO) and ovarian carcinoma (OvCa) cells during the time period when thermotolerance (TT) is observed (Ca Res 45,3029). SOD is also increased in OvCa cells following transient exposure to ethanol, carbonyl cyanide-N-chlorophenyl-hydrazone, or hypoxia; all treatments which induce TT (1986 Rad Res Abstr Co-2). As these experiments involved refeeding of cell cultures, the authors examined the effect of refeeding on SOD in CHO cells. Refeeding confluent CHO cells with fresh McCoy's 5A medium containing 10% FCS decreased SOD 0 to 6 hours after refeeding, which was due to loss of the mitochondrial or Mn SOD. Addition of glucose to the medium at the concentration originally found in the medium caused a similar decline in SOD. At 6-24 hours after refeeding or the addition of glucose an increase in Mn SOD was observed. These results suggest metabolic status can affect Mn SOD in the cell. The possible role of metabolic regulation of SOD in heat sensitivity is being investigated

  3. Vitamin K metabolism in Chinese Hamster Ovary cells

    International Nuclear Information System (INIS)

    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. 106 cells. After 24 hours, 3H 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

  4. Expression of UV-irradiated adenovirus in normal and UV-sensitive Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The chinese hamster ovary (CHO) cell mutants UV-20, UV-24, and UV-41 are abnormally sensitive to UV and harbour various defects lin their ability to repair cellular DNA. This study has examined the expression of UV-irradiated AD2 in these cells. HCR of UV-irradiated Ad2, as measured by viral structural antigen (Vag) formation or progeny production, was found to be similar for the normal and the UV-sensitive CHO strains. UV-irradiation of Ad2 (1200 J/m/sup 2/) resulted in a delay of Vag expression of 18 hours in normal human fibroblasts, which is thought to reflect the time required for removal of UV-induced lesions from the DNA before viral DNA synthesis can proceed. However, a similar UV-irradiation of Ad2 did not result in a delay of Vag expression for infection of CHO cells, suggesting that UV-induced lesions in Ad2 DNA do not inhibit its replication in CHO cells. These results indicate a fundamental difference in the processing of UV-irradiated AD2-DNA in CHO as compared to human cells

  5. Existence of an Endogenous Glutamate and Aspartate Transporter in Chinese Hamster Ovary Cells

    Institute of Scientific and Technical Information of China (English)

    Xunhe JI; Yuhua JIN; Yaoyue CHEN; Chongyong LI; Lihe GUO

    2007-01-01

    Chinese hamster ovary cells show endogenous high-affinity Na+-dependent glutamate transport activity. This transport activity is kinetically similar to a glutamate transporter family strategically expressed in the central nervous system and is pharmacologically unlike glutamate transporter-1 or excitatory amino acid carrier 1. The cDNA of a glutamate/aspartate transporter (GLAST)-like transporter was obtained and analyzed. The deduced amino acid sequence showed high similarity to human, mouse, and rat GLAST. We concluded that a GLAST-like glutamate transporter exists in Chinese hamster ovary cells that might confer the endogenous high-affinity Na+-dependent glutamate transport activity evident in these cells.

  6. 5-azacytidine induces micronuclei in and morphological transformation of Syrian hamster embryo fibroblasts in the absence of unscheduled DNA synthesis

    OpenAIRE

    Stopper, Helga; Pechan, R; Schiffmann, D

    2012-01-01

    lt is known that 5-azacytidine (5-AC) induces tumors in several organs of rats and mice. The mechanisms of these effects are still poorly understood although it is known that 5-AC can be incorporated into DNA. Furthermore, it can inhibit DNA methylation. The known data on its clastogenic andjor gene mutation-inducing potential are still controversial. Therefore, we have investigated the kinds of genotoxic effects caused by 5-AC in Syrian hamster embryo (SHE) fibroblasts. Three different endp6...

  7. Characterization of telomeric repeats in metaphase chromosomes and interphase nuclei of Syrian Hamster Fibroblasts

    Directory of Open Access Journals (Sweden)

    Solovjeva Liudmila V

    2012-09-01

    Full Text Available Abstract Background Rodents have been reported to contain large arrays of interstitial telomeric sequences (TTAGGGn (ITS located in pericentromeric heterochromatin. The relative sizes of telomeric sequences at the ends of chromosomes (TS and ITS in Syrian hamster (Mesocricetus auratus cells have not been evaluated yet, as well as their structural organization in interphase nuclei. Results FISH signal distribution analysis was performed on DAPI-banded metaphase chromosomes of Syrian hamster fibroblasts, and relative lengths of telomere signals were estimated. Besides well-distinguished FISH signals from ITS located on chromosomes ##2, 4, 14, 20 and X that we reported earlier, low-intensity FISH signals were visualized with different frequency of detection on all other metacentric chromosomes excluding chromosome #21. The analysis of 3D-distribution of TS in interphase nuclei demonstrated that some TS foci formed clearly distinguished associations (2–3 foci in a cluster in the nuclei of cells subjected to FISH or transfected with the plasmid expressing telomeric protein TRF1 fused with GFP. In G0 and G1/early S-phase, the average total number of GFP-TRF1 foci per nucleus was less than that of PNA FISH foci in the corresponding cell cycle phases suggesting that TRF1 overexpression might contribute to the fusion of neighboring telomeres. The mean total number of GFP-TRF1 and FISH foci per nucleus was increased during the transition from G0 to G1/early S-phase that might be the consequence of duplication of some TS. Conclusions The relative lengths of TS in Syrian hamster cells were found to be moderately variable. All but one metacentric chromosomes contain ITS in pericentromeric heterochromatin indicating that significant rearrangements of ancestral genome occurred in evolution. Visualization of GFP-TRF1 fibrils that formed bridges between distinct telomeric foci allowed suggesting that telomere associations observed in interphase cells are

  8. 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; Nagarajan, Harish; Yerganian, George; O'Brien, Edward; Bordbar, Aarash; Roth, Anne M; Rosenbloom, Jeffrey; Bian, Chao; Xie, Min; Chen, Wenbin; Li, Ning; Baycin-Hizal, Deniz; Latif, Haythem; Förster, Jochen; Betenbaugh, Michael; Famili, Iman; Xu, Xun; Wang, Jun; Palsson, Bernhard O

    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 of this...

  9. Induction of chromosome aberrations in Chinese hamster cells after heavy ion irradiation

    International Nuclear Information System (INIS)

    The induction of structural chromosome changes in V 79-Chinese hamster cells following heavy ion irradiation is studied. Asynchronous exponentially growing cells are exposed to the heavy ion beams at the Unilac, Darmstadt and the Ganil, Caen. The induction of chromosome aberrations was measured as a function of time after exposure. (orig./MG)

  10. 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; Kristensen, Claus; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    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...

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

    DEFF Research Database (Denmark)

    Xu, Xun; Pan, Shengkai; Liu, Xin; Chen, Wenbin; Xie, Min; Wang, Wenliang; Nagarajan, Harish; Lewis, Nathan; Famili, Iman; Palsson, Bernhard O.; Cai, Zhiming; Gui, Yaoting; Hammond, Stephanie; Lee, Kelvin H.; Andersen, Mikael Rørdam; Neff, Norma; Passarelli, Benedetto; Koh, Winston; Fan, H. Christina; Wang, Jianbin; Quake, Stephen R.; Betenbaugh, Michael; Palsson, Bernhard; Wang, Jun

    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...

  12. Effects of inhibitors of protein kinase C and NO-synthase on the radiation-induced cytogenetic adaptive response in Chinese hamster cells in culture

    International Nuclear Information System (INIS)

    The effect of the serine-threonin kinase inhibitor - staurosporine and inhibitor of NO-synthase - L-NAME on the radiation-induced adaptive response were studied in fibroblasts of Chinese hamster in culture. It is shown that staurosporine and L-NAME inhibit cytogenetic adaptive response induced by β-particles in low doses. Inhibition is not connected with radiosensitizing effect of these agents. L-NAME decreases significantly the γ-rays-induced chromosome aberration yield also. Study confirms the role of protein kinase C in induction of the adaptive response and participation of NO-synthase in this process is noticed for the first time

  13. Replication of Chinese hamster embryo cells transformed by temperature-sensitive T-antigen mutants of simian virus 40.

    OpenAIRE

    Robinson, C C; Swartzendruber, D E; Lehman, J M

    1980-01-01

    Chinese hamster embryo cells transformed by simian virus 40 temperature-sensitive T-antigen mutants replicated when confluent at 40.5 degrees C, regardless of the selection method, selection temperature, or virus strain used.

  14. Complementation of a methotrexate uptake defect in Chinese hamster ovary cells by DNA-mediated gene transfer.

    OpenAIRE

    Underhill, T M; Flintoff, W F

    1989-01-01

    A methotrexate-resistant Chinese hamster ovary cell line deficient in methotrexate uptake has been complemented to methotrexate sensitivity by transfection with DNA isolated from either wild-type Chinese hamster ovary or human G2 cells. Primary and secondary transfectants regained the ability to take up methotrexate in a manner similar to that of wild-type cells, and in the case of those transfected with human DNA, to contain human-specific DNA sequences. The complementation by DNA-mediated g...

  15. Interspecific complementation between mouse and Chinese hamster cell mutants hypersensitive to ionizing radiation

    International Nuclear Information System (INIS)

    Interspecific and intraspecific hybrids were formed between mouse and Chinese hamster cell mutants hypersensitive to ionizing radiation and their radiosensitivities were examined. Chinese hamster cell mutants irs1, irs2 and irs3 and mouse mammary carcinoma cell mutants SX9 and SX10 have been found to belong to five different complementation groups. A radiosensitive mouse lymphoma cell line L5178Y-S has been demonstrated to be different from the X-ray sensitive mouse cell mutants M10 and LX830, both of which are derived from L5178Y cells, in their complementation groups. L5178Y-S is also distinct from SX9 and SX10. (author)

  16. Effects of Supplementation of Various Medium Components on Chinese Hamster Ovary Cell Cultures Producing Recombinant Antibody

    OpenAIRE

    Kim, Do Yun; Lee, Joon Chul; Chang, Ho Nam; Oh, Duk Jae

    2005-01-01

    Thirteen vitamins, twenty amino acids, hormones, inorganic salts, and other chemical agents, which constitute typical serum-free media, were evaluated for the development of fortified medium to enhance cell growth and productivity of recombinant antibody in the cultures of the recombinant Chinese hamster ovary (rCHO) cells. Two different rCHO cell lines, rCHO-A producing recombinant antibodies against the human platelet and rCHO-B secreting recombinant antibodies against the S surface antigen...

  17. Effect of lazer radiation on Chinese hamster cells cultured in vitro

    International Nuclear Information System (INIS)

    Helium-neon (lambda=633 nm) and neodymium (lambda=534 nm) lazer radiation as well as monochromatic radiation of non-lazer sources (540 and 630 nm) produced a stimulatory effect on the survival rate of Chinese hamster cells. It was shown that the stimulatory effect is related mainly to the action of radiation on the adhesive poperties of cells. With the combined action of X- and lazer-radiation the deleterious effect of X-radiation is reduced

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

    International Nuclear Information System (INIS)

    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)

  19. Comparative metabolic disposition of [1-Me14C]caffeine in rats, mice, and Chinese hamsters

    International Nuclear Information System (INIS)

    The metabolic disposition of [1-Me14C]caffeine has been studied and compared in three male rodent species: the rat, the mouse, and the Chinese hamster. No interspecies differences appeared in urinary and fecal excretion of radioactivity. However, 1-methyldemethylation was significantly more important in the rat with 20.6 +/- 0.8% of the dose recovered as 14CO2 compared with the Chinese hamster, 16.1 +/- 2%, and the mouse, 13.9 +/- 0.9%. HPLC and TLC analysis of 1-methyl-labeled metabolites showed that the rat exhibits a significantly higher urinary excretion of the four trimethyl derivatives: caffeine, 1,3,7-trimethyluric acid, trimethylallantoin, and 6-amino-5-[N-formylmethylamino]-1,3-dimethyluracil [40.8% of total urine radioactivity) when compared with the Chinese hamster (21.1%) and the mouse (19.7%). Compared with man (6%), these rodents have a greater ability to excrete caffeine without any demethylation. The rat was also characterized by a higher excretion of theophylline while the Chinese hamster excreted more paraxanthine, 1-methylxanthine, and the uracil derivative of paraxanthine. In the mouse, in addition to 1-methylxanthine and 1-methyluric acid, higher amounts of 1,3- and 1,7-dimethyluric acid were found. The mouse was particularly characterized by the presence of an unknown polar metabolite amounting to 22 +/- 3% of urine radioactivity. This metabolite must be produced from paraxanthine because its quantitative formation was inversely related to the excretion of paraxanthine and its metabolites. The observations that this metabolite is neither 5-acetylamino-6-amino-3-methyluracil nor 5-acetylamino-6-formylamino-3-methyluracil reported in humans demonstrate that both quantitative and qualitative interspecies differences occur for caffeine metabolism

  20. Binding and uptake of diphtheria toxin by toxin-resistant Chinese hamster ovary and mouse cells.

    OpenAIRE

    Didsbury, J R; Moehring, J M; Moehring, T. J.

    1983-01-01

    We investigated two phenotypically distinct types of diphtheria toxin-resistant mutants of Chinese hamster cells and compared their resistance with that of naturally resistant mouse cells. All are resistant due to a defect in the process of internalization and delivery of toxin to its target in the cytosol, elongation factor 2. By cell hybridization studies, analysis of cross-resistance, and determination of specific binding sites for 125I-labeled diphtheria toxin, we showed that these cell s...

  1. High cell density and productivity culture of Chinese hamster ovary cells in a fluidized bed bioreactor

    OpenAIRE

    Kong, D.; Cardak, S.; Chen, M.; Gentz, R; Zhang, J.

    1999-01-01

    A recombinant Chinese hamster ovary clone was cultivated in a 2L Cytopilot Mini fluidized bed bioreactor using Cytoline 1 microcarriers and a 10L B. Braun stirred tank bioreactor with Cytodex 1 microcarriers. Cytoline 1 is a macroporous polyethylene microcarrier and Cytodex 1 is a solid DEAE-dextran microcarrier. Cytoline 1 microcarriers in the fluidized bed bioreactor were gently mixed by an uplifting flow. Circulation and sparging in Cytopilot Mini were separated from the fluidized microcar...

  2. Selection of mutant Chinese hamster ovary cells altered glycoproteins by means of tritiated fucose suicide.

    OpenAIRE

    Hirschberg, C B; Baker, R.M.; Perez, M.; Spencer, L A; Watson, D

    1981-01-01

    Mutant Chinese hamster ovary cells altered in glycoproteins have been isolated by selecting for ability to survive exposure to [6-3H]fucose. Mutagenized wild-type cells were permitted to incorporate [3H]fucose to approximately 1 cpm of trichloroacetic acid-insoluble radioactivity per cell and then frozen for several days to accumulate radiation damage. The overall viability of the population was reduced by 5- to 50-fold. Four consecutive selection cycles were carried out. The surviving cells ...

  3. Subcellular distribution of 239Pu in the liver of rat, mouse, Syrian and Chinese hamster

    International Nuclear Information System (INIS)

    An attempt was made to elucidate the biochemical mechanisms responsible for the species differences in the biological half life of plutonium-239 in the liver of rats, mice, Syrian hamsters and Chinese hamsters. Six days after intravenously administered Pu-239, the animals were given Triton i.p. which causes a shift of the density of the lysosomes and thus any lysosomally-associated material can be recognised by a parallel shift. On the tenth day, an MLP fraction was obtained by differential centrifugation of the liver homogenates; the distribution of radioactivity and marker enzymes was then examined after centrifugation of the MLP fraction in a sucrose density gradient. If the parallelism between the shift of Pu-239 and acid phosphatase is taken as a measure for the extent of lysosomal binding, there is clear evidence for association with these organelles for rats and mice, the species with rapid Pu elimination; however these organelles appear to become less important in the species with longer Pu retention, Syrian and especially Chinese hamster. (U.K.)

  4. Effect of neon ions on synchronized Chinese hamster cells

    International Nuclear Information System (INIS)

    The variation in radiosensitivity across the cell cycle after exposure to neon ions and 60Co γ-rays is reported for cultured hamster cells. The cells were first synchronized by mitotic selection, then resynchronized in the region of the G1/S boundary by treatment with 10-3 M hydroxyurea. Although the use of hydroxyurea improves the synchrony, it does sensitize cells at the G1/S boundary to some degree. The cells were exposed at the plateau and the distal peak position of a neon ion beam modified by a 10 cm wide ridge filter. The results indicate that the variation (ratio of maximum to minimum survival after fixed doses of radiation that are approximately matched to produce similar cell killing) was approximately 80 to 100-fold for 60Co γ-rays and neon ions at the plateau, and 25-fold for distal peak neon ions. While the r.b.e. of distal peak neon ions decreased rapidly with increasing dose for cells in late S-phase, the r.b.e. is independent of dose for cells at the G1/S boundary. (author)

  5. Interchromosomal distribution of gamma ray-induced chromatid aberrations in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Inter chromosomal distributions of breakpoints from chromatid-type aberrations induced by gamma rays in Chinese hamster ovary cells were analyzed. In most chromosomes the distribution was as expected from chromosome lengths for simple breaks or the respective relative corrected length in case of exchanges. There were deviations from expectation in a few chromosomes for chromatid breaks, interchanges, intra-arm intra changes and inter-arm intra changes. Especially interesting are the results concerning chromosomes 2 and 8, which were more often involved in exchanges than expected. An 'exchange phenotype' for these chromosomes is proposed and possible explanations for the nonrandom distribution of chromosome breakpoints are presented. (author)

  6. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

    OpenAIRE

    Haredy, Ahmad M.; Nishizawa, Akitoshi; Honda, Kohsuke; Ohya, Tomoshi; Ohtake, Hisao; Omasa, Takeshi

    2013-01-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host c...

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  10. 5-Azacytidine Induces Transgene Silencing by DNA Methylation in Chinese Hamster Cells

    OpenAIRE

    Broday, Limor; Lee, Yong-Woo; Costa, Max

    1999-01-01

    The cytosine analog 5-azacytidine (5-AzaC) is a demethylating agent that is also known to induce mutagenesis in mammalian cells. In this study, the mutagenic potential of this drug was tested in the G10 and G12 transgenic Chinese hamster cell lines, which have a single bacterial gpt gene integrated into the genome at different sites, with its expression driven by a simian virus 40 (SV40) promoter. We show that the mutation frequencies following a 48-h exposure to different concentrations of 5...

  11. Survival and kinetics of Chinese hamster ovary cell subpopulations induced by Adriamycin and radiation

    International Nuclear Information System (INIS)

    Mitotic selection of Chinese hamster ovary (CHO) cells, at 10 min intervals after the initiation of Adriamycin and/or x-ray treatment was used to measure the kinetics and survival of cells which progressed without delay, the ''refractory'' cells, the cells that reached mitosis only after recovery from the treatment-induced delay, the ''recovered'' cells, and the survival of the cells remaining attached to the flask 5 h after treatment. The cell kinetics were determined from the rate at which cells entered mitosis, and the reproductive integrity from the survival of the selected refractory, recovered and remaining (unselected) cells

  12. Dimethylsulfoxide reduces the x-ray-induced G2 delay in chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The effects of dimethylsulfoxide (DMSO) on radiation-induced G2 delay and on each stage in mitotic phase were studied. The G2 delay was reduced by the postirradiation treatment of Chinese hamster ovary cells by over 2 %. DMSO at 2 % had no effect on the progression of the cells through metaphase, anaphase or telophase, when added after mechanical collection of cells at the mitotic phase. DMSO over 5 %, and particularly over 7 %, led to a retardation at metaphase, with little effect on anaphase or telophase. (author)

  13. Calculation of response of Chinese hamster cells to ions based on track structure theory

    Institute of Scientific and Technical Information of China (English)

    LiuXiao-Wei; ZhangChun-Xiang

    1997-01-01

    Considering biological cells as single target two-hit detectors,an analytic formula to calculate the response of cells to ions is developed based on track structure theory.In the calculation,the splitting deposition energy between ion kill mode and γ kill mode is not used.The results of calculation are in agreement with the experimental data for response of Chinese hamster cells,whose response to γ rays can be described by the response function of single target two hit detector to ions.

  14. Microphysiometric analysis of human α1a-adrenoceptor expressed in Chinese hamster ovary cells

    OpenAIRE

    Taniguchi, Takanobu; Inagaki, Rika; Murata, Satoshi; Akiba, Isamu; Muramatsu, Ikunobu

    1999-01-01

    The human recombinant α1a-adrenoceptor (AR) has been stably expressed in Chinese hamster ovary cells. Four stable clones, aH4, aH5, aH6 and aH7, expressing 30, 370, 940 and 2900 fmol AR mg−1 protein, respectively, have been employed to characterize this AR subtype using radioligand binding and microphysiometry to measure extracellular acidification rates.Noradrenaline (NA) gave concentration-dependent responses in microphysiometry with increasing extracellular acidification rates. The potency...

  15. The evolution of chromosomal instability in Chinese hamster cells: a changing picture?

    Science.gov (United States)

    Ponnaiya, B.; Limoli, C. L.; Corcoran, J.; Kaplan, M. I.; Hartmann, A.; Morgan, W. F.

    1998-01-01

    PURPOSE: To investigate the kinetics of chromosomal instability induced in clones of Chinese hamster cells following X-irradiation. MATERIALS AND METHODS: X-irradiated clones of GM10115, human-hamster hybrid cells containing a single human chromosome 4 (HC4), have been previously established. These clones were defined as unstable if they contained > or = three subpopulations of cells with unique rearrangements of HC4 as detected by FISH. Stable and unstable clones were analysed by FISH and Giemsa staining at various times post-irradiation. RESULTS: While most of the stable clones continued to show chromosomal stability of HC4 over time, one became marginally unstable at approximately 45 population doublings post-irradiation. Clones exhibiting chromosomal instability had one of several fates. Many of the unstable clones were showed similar levels of instability over time. However, one unstable clone became stable with time in culture, while another became even more unstable over time. Cytogenetic analyses of all clones after Giemsa staining indicated that in some clones the hamster chromosomes were rearranged independent of HC4, demonstrating increased frequencies of chromatid breaks and dicentric chromosomes. The majority of the unstable clones also had higher yields of chromatid gaps. CONCLUSIONS: These data demonstrate the dynamic nature of chromosomal instability as measured by two different cytogenetic assays.

  16. Subcellular distribution of Pu-239 in the liver of rat, mouse, Syrian and Chinese hamster

    International Nuclear Information System (INIS)

    The aim of our studies was to elucidate the biochemical mechanisms responsible for the differences in the biological half life of actinides in the liver of different mammalian species. Rats and mice were chosen as models for rapid elimination, and Syrian and Chinese hamsters as models for slow elimination. To distinguish between fixation in lysosomes and mitochondria, the lysosomes were isolated following injection of Triton WR1339 6 days after 239Pu administration. The animals were sacrificed 4 days later. In order to study the possible association with ferritin, 59Fe was also injected. Liver homogenates were subjected to differential and isopycnic centrifugation in a sucrose density gradient. The typical shift in the density of the lysosomal marker acid phosphatase from rho approximately 1.2 to rho approximately 1.1 following Triton WR1339 injection was observed in all species. It was possible therefore to separate lysosomes from other cell organelles, especially mitochondria. It was concluded that: 1) Mitochondria can virtually be excluded as binding sites in all four species; 2) Lysosomes are one important storage site in rats, mice and Syrian hamsters; 3) If 239Pu is bound to another cell constituent in addition to lysosomes in the hamster species (which is not yet proven) its density should be approximately 1.17. (H.K.)

  17. Onderzoek naar de inductie van chromosoomafwijkingen en "sister-chromatid exchanges" door divinylbenzeen met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1987-01-01

    Divinylbenzeen induceert geen chromosoomafwijkingen in Chinese hamster cellen in vitro, noch in aanwezigheid noch in afwezigheid van een systeem voor metabolische activering ; divinylbenzeen induceert in deze cellen wel zusterchromatide uitwisselingen (SCE's) maar alleen in aanwezigheid van een systeem voor metabolische activering. Er zijn aanwijzingen dat tijdens de metabolische omzetting van divinylbenzeen, via een epoxide, onder speciale omstandigheden ook chromosoomafwijkingen kunnen...

  18. Radiosensitization of Chinese hamster cells by pimonidazole (Ro 03-8799) at low x-ray doses

    International Nuclear Information System (INIS)

    The authors report on the radiosensitization of hypoxic Chinese hamster cells by pimonidazole (Ro 03-8799) which has undergone evaluation in clinical trials. The study also includes data obtained concurrently with misonidazole for comparative purposes. The survival data were fitted to the linear quadratic model: 1n S = -(αD + βD2 and estimates of α and β derived. (author)

  19. 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 t...

  20. MULTIPLE-ENDPOINT MUTAGENESIS WITH CHINESE HAMSTER OVARY (CHO) CELLS: EVALUATION WITH EIGHT CARCINOGENIC AND NON-CARCINOGENIC COMPOUNDS

    Science.gov (United States)

    Using Chinese hamster ovary (CHO) cells in culture, the authors have defined an assay, CHO/HGPRT, to quantify mutagen-induced cytotoxicity and mutations at the hypoxanthine-guanine phosphoribosyltransferase (hgprt) locus. This assay permits elucidation of the structure-activity r...

  1. Transformation of UV-hypersensitive Chinese hamster ovary cell mutants with UV-irradiated plasmids

    International Nuclear Information System (INIS)

    Transfection of UV-hypersensitive, DNA repair-deficient Chinese hamster ovary (CHO) cell lines and parental, repair-proficient CHO cells with UV-irradiated pHaprt-1 or pSV2gpt plasmids resulted in different responses by recipient cell lines to UV damage in transfected DNA. Unlike results reported for human cells, UV irradiation of transfecting DNA did not stimulate genetic transformation of CHO recipient cells. In repair-deficient CHO cells, proportionally fewer transformants were produced with increasing UV damage than in repair-proficient cells in transfections with UV-irradiated hamster adenine phosphoribosyltransferase (APRT) gene contained in plasmid pHaprt-1. Transfection of CHO cells with UV-irradiated pSV2gpt resulted in neither decline in transformation frequencies in repair-deficient cell lines relative to repair-proficient cells nor stimulation of genetic transformation by UV damage in the plasmid. Blot hybridization analysis of DNA samples isolated from transformed cells showed no dramatic changes in copy number or arrangement of transfected plasmid DNA with increasing UV dose. The authors conclude responses of recipient cells to UV-damaged transfecting plasmids depend on type of recipient cell and characteristics of the genetic sequence used for transfection. (author)

  2. Detachment variants of Chinese hamster cells. Hyaluronic acid as a modulator of cell detachment

    Energy Technology Data Exchange (ETDEWEB)

    Barnhart, B.J.; Cox, S.H.; Kraemer, P.M.

    1979-01-01

    Variants of the Chinese hamster cell line CHO have been isolated and characterized with respect to attachment and trypsin- or EGTA-mediated detachment kinetics, cell morphologies, and the complex carbohydrates (labeled with (/sup 3/H)glucosamine) of the cell surface. The variant which was more readily detached from the substratum exhibited a more rounded cell shape and had three times more label as hyaluronic acid on the cell surface than the parental cell. The slowly detaching variant had a morphology similar to the parental cell but only half the radioactivity ascribable to hyaluronic acid. Endogenous levels of cAMP were unaltered in the variants. Exogenous db-cAMP caused the cells to elongate and flatten but did not alter the characteristic detachment kinetics. The role of hyaluronic acid as a modulator of the cell substratum interface is discussed.

  3. 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...... consists of four techniques compatible with 96-well microplates: lipid-based transient transfection, cell cultivation in microplates, cell counting and antibody-independent product titer determination based on split-GFP complementation. We were able to demonstrate growth profiles and volumetric...... to reduce production costs significantly. The aim of this study was to establish a versatile target gene screening platform for improving productivity for primarily non-mAb glycoproteins with complete interchangeability of model proteins and target genes using transient expression. The platform...

  4. Dielectric model for Chinese hamster ovary cells obtained by dielectrophoresis cytometry.

    Science.gov (United States)

    Salimi, E; Braasch, K; Butler, M; Thomson, D J; Bridges, G E

    2016-01-01

    We present a dielectric model and its parameters for Chinese hamster ovary (CHO) cells based on a double-shell structure which includes the cell membrane, cytoplasm, nuclear envelope, and nucleoplasm. Employing a dielectrophoresis (DEP) based technique and a microfluidic system, the DEP response of many single CHO cells is measured and the spectrum of the Clausius-Mossotti factor is obtained. The dielectric parameters of the model are then extracted by curve-fitting to the measured spectral data. Using this approach over the 0.6-10 MHz frequency range, we report the values for CHO cells' membrane permittivity, membrane thickness, cytoplasm conductivity, nuclear envelope permittivity, and nucleoplasm conductivity. The size of the cell and its nuclei are obtained using optical techniques. PMID:26858823

  5. Further characterization of chinese hamster mutagen sensitive mutants using calicheamycin and neocarcinostatin

    International Nuclear Information System (INIS)

    To further characterize mutagen sensitive Chinese hamster V79 mutant cell lines two new radiomimetic agents i.e. calicheamycin (CAL) and neocarcinostatin (NCS) were used. Whereas X-rays produces a variety of non-specific lesions in the DNA, mainly single strand breaks (SSB), CAL induces only double strand breaks (DSB) at sequence specific sites (TCCT). NCS, on the other hand, causes SSB and to a much lesser extent apurinic sites at AGC sequences in the DNA. The obtained results demonstrate in most of the mutants and expected parallelism between X-ray sensitivity and sensitivity to the antitumor antibiotics CAL and NCS. Furthermore, enhanced sensitivities for chromosomal aberrations are overall and not due to specific types of aberrations. At present an explanation for the recorded chromosomal hypo-sensitivity of V-H1 cells for NCS awaits further experimentation. (authors)

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

    International Nuclear Information System (INIS)

    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 (3H) hypoxanthine for 5 or 10 min, followed by storage of 3H-labelled cells at -700C for 4-10 days. 12 clones that survived the 3rd kill cycle were tested for incorporation of (3H)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.)

  7. Effects of ultrasound, cysteamine, and x-rays on V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    The effects of biomedical ultrasound on a subline of Chinese hamster V79 cells were examined for the following endpoints: (1) cell lysis, loss of viability and growth alteration induced by ultrasound. (2) Cell sensitivity to ultrasound as a function of cell cycle position after synchronization by mitotic collection; (3) Cell lysis and survival after addition of cysteamine before and during ultrasound or x-ray treatment. These results indicate that at high, but not low, intensities ultrasonically induced free radicals perturb the reproductive integrity of cells which survive lysis although they do not play a role in cell lysis. Thus, at least at high intensities, free radical formation is one but not the only mechanism responsible for ultrasound's effects on cells

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  10. Induction of repair functions by hydrogen peroxide in Chinese hamster cells

    International Nuclear Information System (INIS)

    Hydrogen peroxide has been found to kill Chinese hamster V79 cells as an exponential function of dose. When a small dose (0.9 μg/ml for 1 h) was used as a pretreatment, before exposure to higher concentrations of the same agent, the cells became more resistant to killing than those which were not so pretreated. The presence of cycloheximide or benzamide, during this pretreatment, inhibited this observed increase in resistance. This pretreatment also resulted in decreased killing efficiency by MNNG and gamma-rays, but had no effect upon UV-light-induced killing. The results suggest that proteins (repair enzymes?) are synthesized after treatment with the small dose of hydrogen peroxide, and that these induced proteins enhance the cellular repair functions for agents causing DNA breaks. (author)

  11. Genetic analysis of tumorigenesis: a conserved region in the human and Chinese hamster genomes contains genetically identified tumor-suppressor genes

    International Nuclear Information System (INIS)

    Regional chromosome homologies were found in a comparison of human 11p with Chinese hamster 3p. By use of probes that recognize six genes of human 11p (INS, CAT, HBBC, CALC, PTH, and HRAS), the corresponding genes were localized by in situ hybridization on Chinese hamster chromosome 3. INS and CAT were located close to the centromere on 3p, whereas HBBC, CALC, and PTH were at 3q3-4 and HRAS at 3q4. Extensive prior data from chromosome studies of tumorigenic and tumor-derived Chinese hamster cells have suggested the presence of a tumor-suppressor gene on 3p. Two tumor-suppressor genes have been described on human 11p, one linked to CAT and one to INS. The present study raises the possibility that the Chinese hamster suppressor may be closely linked to INS or CAT

  12. Hyperthermia-induced increase in potassium transport in Chinese hamster cells. Appendix: application of compartmental analysis to the determination of ion fluxes in Chinese hamster cells

    International Nuclear Information System (INIS)

    The effect of hyperthermia (420C) on K+ transport has been examined by monitoring the uptake of 42KCl by Chinese hamster (line CHO) cells at both 370 and 420C as well as 370C following a 30-min treatment at 420C. Early studies showed that CHO cells exhibit two components of uptake at both 370 and 420C. Consequently, it was necessary to determine rate equations describing a three-compartment system (i.e., the bathing medium and two cell-associated compartments) and apply them to this system. Using the equations describing the behavior of the tracer in each compartment as well as the general solutions given by Robertson et al, a method was developed for obtaining the two components of influx. The two transport rates were determined from equations arising from mathematical analysis and requiring only measurable quantities for their solutions. The results of this study showed that (1) both components of influx at 420C are increased over influx at 370C; (2) the increase is significant (by an average 68% for the rapid component and 55% for the slow component); and (3) the increase is due entirely to an increase in active transport. The increased active transport is both immediate and quickly reversible when cells are returned to 370C; resumption of cell division is delayed for several additional hours, indicating that changes in potassium transport are not directly responsible for the prolonged delay in cell division. Rather, the results suggest that increased activity of the membrane pump may be the initial event in a series of events resulting from heat treatment

  13. Intravenously Administered Recombinant Human Type VII Collagen Derived from Chinese Hamster Ovary Cells Reverses the Disease Phenotype in Recessive Dystrophic Epidermolysis Bullosa Mice.

    Science.gov (United States)

    Hou, Yingping; Guey, Lin T; Wu, Timothy; Gao, Robert; Cogan, Jon; Wang, Xinyi; Hong, Elizabeth; Ning, Weihuang Vivian; Keene, Douglas; Liu, Nan; Huang, Yan; Kaftan, Craig; Tangarone, Bruce; Quinones-Garcia, Igor; Uitto, Jouni; Francone, Omar L; Woodley, David T; Chen, Mei

    2015-12-01

    Recessive dystrophic epidermolysis bullosa (RDEB) is an inherited disorder characterized by skin fragility, blistering, and multiple skin wounds with no currently approved or consistently effective treatment. It is due to mutations in the gene encoding type VII collagen (C7). Using recombinant human C7 (rhC7) purified from human dermal fibroblasts (FB-rhC7), we showed previously that intravenously injected rhC7 distributed to engrafted RDEB skin, incorporated into its dermal-epidermal junction (DEJ), and reversed the RDEB disease phenotype. Human dermal fibroblasts, however, are not used for commercial production of therapeutic proteins. Therefore, we generated rhC7 from Chinese hamster ovary (CHO) cells. The CHO-derived recombinant type VII collagen (CHO-rhC7), similar to FB-rhC7, was secreted as a correctly folded, disulfide-bonded, helical trimer resistant to protease degradation. CHO-rhC7 bound to fibronectin and promoted human keratinocyte migration in vitro. A single dose of CHO-rhC7, administered intravenously into new-born C7-null RDEB mice, incorporated into the DEJ of multiple skin sites, tongue and esophagus, restored anchoring fibrils, improved dermal-epidermal adherence, and increased the animals' life span. Furthermore, no circulating or tissue-bound anti-C7 antibodies were observed in the mice. These data demonstrate the efficacy of CHO-rhC7 in a preclinical murine model of RDEB. PMID:26203639

  14. The subcellular distribution of 239Pu, 241Am and 59Fe in the liver of rat and Chinese hamster as dependent on time

    International Nuclear Information System (INIS)

    The subcellular distribution of monomeric 239Pu, 241Am and iron in rat and Chinese hamster liver has been investigated by sucrose-, metrizamide- and Percoll-density gradients. In rat liver, the transuranium elements become and remain bound to typical lysosomes primary storage organelle in Chinese hamster liver. However, their apparent density in sucrose decreases with time, which possible indicates transition into telolysomes. The transuranium nuclides show a subcellular distribution which is quite different from that of iron. (orig.)

  15. Host range restriction of vaccinia virus in Chinese hamster ovary cells: relationship to shutoff of protein synthesis

    International Nuclear Information System (INIS)

    Chinese hamster ovary cells were found to be nonpermissive for vaccinia virus. Although early virus-induced events occurred in these cells (RNA and polypeptide synthesis), subsequent events appeared to be prevented by a very rapid and nonselective shutoff of protein synthesis. Within less than 2 h after infection, both host and viral protein syntheses were arrested. At low multiplicities of infection, inhibition of RNA synthesis with cordycepin resulted in failure of the virus to block protein synthesis. Moreover, infection of the cells in the presence of cycloheximide prevented the immediate onset of shutoff after reversal of cycloheximide. Inactivation of virus particles by uv irradiation also impaired the capacity of the virus to inhibit protein synthesis. These results suggested that an early vaccinia virus-coded product was implicated in the shutoff of protein synthesis. Either the nonpermissive Chinese hamster ovary cells were more sensitive to this inhibition than permissive cells, or a regulatory control of the vaccinia shutoff function was defective

  16. Onderzoek naar de inductie van chromosoomafwijkingen en "sister-chromatid exchanges" door vinyltolueen met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1987-01-01

    Vinyltolueen induceert geen chromosoomafwijkingen in V79 Chinese hamster cellen, noch in aanwezigheid noch in afwezigheid van ratte S9 als systeem voor metabolische activering. In dezelfde cellen wordt wel een inductie van zuster chromatide uitwisselingen (SCE's) gevonden door vinyltolueen, maar alleen in aanwezigheid van metabolische activering. Er wordt verondersteld dat een tweetal metabolieten verantwoordelijk is voor de genotoxische werking van vinyltolueen.

  17. Muscarinic acetylcholine receptor down-regulation limits the extent of inhibition of cell cycle progression in Chinese hamster ovary cells.

    OpenAIRE

    Detjen, K.; Yang, J; Logsdon, C D

    1995-01-01

    Cellular desensitization is believed to be important for growth control but direct evidence is lacking. In the current study we compared effects of wild-type and down-regulation-resistant mutant m3 muscarinic receptors on Chinese hamster ovary (CHO-K1) cell desensitization, proliferation, and transformation. We found that down-regulation of m3 muscarinic acetylcholine receptors was the principal mechanism of desensitization of receptor-activated inositol phosphate phospholipid hydrolysis in t...

  18. Repair-deficient xeroderma pigmentosum cells made UV light resistant by fusion with X-ray-inactivated Chinese hamster cells.

    OpenAIRE

    Karentz, D; Cleaver, J.E.

    1986-01-01

    Xeroderma pigmentosum (XP) is an autosomal recessive human disease, characterized by an extreme sensitivity to sunlight, caused by the inability of cells to repair UV light-induced damage to DNA. Cell fusion was used to transfer fragments of Chinese hamster ovary (CHO) chromosomes into XP cells. The hybrid cells exhibited UV resistance and DNA repair characteristics comparable to those expressed by CHO cells, and their DNA had greater homology with CHO DNA than did the DNA from XP cells. Cont...

  19. Isolation and characterization of Chinese hamster ovary cell variants defective in adhesion to fibronectin-coated collagen

    OpenAIRE

    1980-01-01

    Variant clones of Chinese hamster ovary (CHO) cells were selected for reduced adhesion to serum-coated tissue culture plates. These clones also displayed reduced adhesion to substrata composed of collagen layers coated with bovine serum or with fibronectin (cold-insoluble globulin). Wild-type (WT) and adhesion variant (ADv) cells grew at comparable rates in suspension culture, but the adhesion variants could not be grown in monolayer culture because of their inability to attach to the substra...

  20. Thresholds for Phosphatidylserine Externalization in Chinese Hamster Ovarian Cells following Exposure to Nanosecond Pulsed Electrical Fields (nsPEF)

    OpenAIRE

    Vincelette, Rebecca L.; Roth, Caleb C.; McConnell, Maureen P.; Payne, Jason A.; Beier, Hope T.; Ibey, Bennett L.

    2013-01-01

    High-amplitude, MV/m, nanosecond pulsed electric fields (nsPEF) have been hypothesized to cause nanoporation of the plasma membrane. Phosphatidylserine (PS) externalization has been observed on the outer leaflet of the membrane shortly after nsPEF exposure, suggesting local structural changes in the membrane. In this study, we utilized fluorescently-tagged Annexin V to observe the externalization of PS on the plasma membrane of isolated Chinese Hamster Ovary (CHO) cells following exposure to ...

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

    OpenAIRE

    Ye Zhang; Véronique Chotteau

    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.

  2. Permeabilization of ultraviolet-irradiated Chinese hamster cells with polyethylene glycol and introduction of ultraviolet endonuclease from Micrococcus luteus.

    OpenAIRE

    Yarosh, D B; Setlow, R B

    1981-01-01

    Chinese hamster V-79 cells were made permeable by treatment with polyethylene glycol and then incubated with a Micrococcus luteus extract containing ultraviolet-specific endonuclease activity. This treatment introduced nicks in irradiated, but not in unirradiated, deoxyribonucleic acid. The nicks remained open for at least 3 h; there was no loss of endonuclease-sensitive sites, and no excision of dimers as measured by chromatography was detected. In addition, there was no increase in ultravio...

  3. Down-regulation of cold-inducible RNA-binding protein does not improve hypothermic growth of Chinese hamster ovary cells producing erythropoietin.

    Science.gov (United States)

    Hong, Jong Kwang; Kim, Yeon-Gu; Yoon, Sung Kwan; Lee, Gyun Min

    2007-03-01

    Discovery of the cold-inducible RNA-binding protein (CIRP) in mouse fibroblasts suggests that growth suppression at hypothermic conditions is due to an active response by the cell rather than due to passive thermal effects. To determine the effect of down-regulated CIRP expression on cell growth and erythropoietin (EPO) production in recombinant Chinese hamster ovary (rCHO) cells at low culture temperature, stable CHO cell clones with reduced CIRP expression level were established by transfecting (rCHO) cells with the CIRP siRNA vector with a target sequence of TCGTCCTTCCATGGCTGTA. For comparison of the degree of specific growth rate (micro) reduction at low culture temperature, three CIRP-reduced clones with different mu and three control clones transfected with null vector were cultivated at two different temperatures, 32 degrees C and 37 degrees C. Unlike mouse fibroblasts, alleviation of hypothermic growth arrest of rCHO cells by CIRP down-regulation was insignificant, as shown by statistical analysis using the t-test (P<0.18, n=3). The ratios of mu at 32 degrees C to micro at 37 degrees C of CIRP-reduced clones and control clones were 0.29+/-0.03 and 0.25+/-0.03 on an average, respectively. Furthermore, it was also found that overexpression of CIRP did not inhibit rCHO cell growth significantly at 37 degrees C. Taken together, the data obtained show that down-regulation of only CIRP in rCHO cells, unlike mouse fibroblasts, is not sufficient to recover growth arrest at low-temperature culture (32 degrees C). PMID:17239640

  4. UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment

    International Nuclear Information System (INIS)

    UV micro-irradiation of a small part of the Chinese hamster nucleus and caffeine post-incubation often results in shattered chromosomes at the first post-irradiation mitosis. In some of these mitotic cells, chromosome shattering is restricted to a few chromosomes spatially related in a small area of the metaphase spread; in others, shattering includes the whole chromosome complement. These 2 types of damage have been called partial and generalized chromosome shattering (PCS and GCS). Using antisera that specifically react with UV-irradiated DNA, we identified micro-irradiated chromatin in interphase nuclei and in mitotic cells with PCS or GCS by indirect immunofluorescence microscopy. In PCS, immunofluorescence staining was found in the damaged area, while the surrounding intact chromosomes were not stained. In GCS, staining was also restricted to a small region of the shattered chromosome complement. In other experiments, cells synchronized in G1 were micro-irradiated in the nucleus, pulse-labelled with [3H]thymidine and post-incubated with caffeine. Autoradiographs of cells with GCS showed unscheduled DNA synthesis restricted to a small chromatin region. (orig./AJ)

  5. Characterization of recombinant human erythropoietin produced in Chinese hamster ovary cells

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.M.; Arakawa, T.; Strickland, T.W.; Yphantis, D.A.

    1987-05-05

    Physicochemical properties of recombinant human erythropoietin were examined. This protein, produced in Chinese hamster ovary cells, showed a conformation apparently identical with the natural product isolated from human urine when examined by circular dichroism, UV absorbance, and fluorescence spectroscopy. Sedimentation equilibrium experiments showed the recombinant erythropoietin preparation to be essentially a single macromolecular component with a molecular weight of 30,400 and a carbohydrate content of 39%. The Stokes radius of recombinant erythropoietin was estimated to be 32 A from gel filtration, much larger than the 20-A radius calculated for a sphere of the observed molecular weight. This difference may be ascribed to the extensive glycosylation. The fluorescence and phosphorescence spectra showed that the luminescent tryptophan(s) is (are) solvent-exposed and can be quenched by I/sup -/ and acrylamide but not by Cs/sup +/. On acid titration, the recombinant erythropoietin showed a conformational transition with a midpoint of pH 4.1. This suggests that the net charges on the protein moiety rather than on the whole molecule play a role in protein structure stability.

  6. [Stable expression of recombinant human podoplanin in Chinese hamster ovary (CHO) cells].

    Science.gov (United States)

    Qu, Le; Zhao, Xingpeng; Fu, Jianxin; Xia, Lijun; Dai, Lan; Ruan, Changgeng; Zhao, Yiming

    2016-01-01

    Objective To construct podoplanin (PDPN) eukaryotic expression plasmid PDPN-pEGFP-N1, establish Chinese hamster ovary (CHO) cell line stably expressing recombinant human PDPN and investigate its biological activity. Methods PDPN cDNA was cloned from HEK293 cells by reverse transcription PCR and recombinant DNA technology and inserted into plasmid pEGFP-N1 labeled by enhanced green fluorescent protein (EGFP). The recombinant vector was identified by PCR, restriction enzyme digestion and DNA sequencing, and then transfected into CHO cells. Recombinant PDPN-EGFP was observed by fluorescent microscopy and CHO cell line with the high expression of PDPN-EGFP was selected by flow cytometry. Recombinant PDPN was detected by Western blotting and the biological activity of the cell line was determined by platelet aggregation assay. Results DNA sequencing and restriction enzyme digestion proved that the gene of PDPN was inserted successfully into pEGFP-N1 plasmid. After stable transfection of the recombinant plasmid into CHO cells, CHO with EGFP could be seen under a fluorescent microscope. The CHO cell line with the high expression of recombinant PDPN-EGFP was obtained after sorting by flow cytometry. Western blotting showed that the recombinant PDPN was expressed on the cell surface. The over-expressing PDPN-EGFP CHO cells were able to induce human platelet aggregation. Conclusion The CHO cell line with the stable and high expression of recombinant PDPN-EGFP has been constructed successfully, and it could induce platelet aggregation. PMID:26728373

  7. Characterization of recombinant human erythropoietin produced in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Physicochemical properties of recombinant human erythropoietin were examined. This protein, produced in Chinese hamster ovary cells, showed a conformation apparently identical with the natural product isolated from human urine when examined by circular dichroism, UV absorbance, and fluorescence spectroscopy. Sedimentation equilibrium experiments showed the recombinant erythropoietin preparation to be essentially a single macromolecular component with a molecular weight of 30,400 and a carbohydrate content of 39%. The Stokes radius of recombinant erythropoietin was estimated to be 32 A from gel filtration, much larger than the 20-A radius calculated for a sphere of the observed molecular weight. This difference may be ascribed to the extensive glycosylation. The fluorescence and phosphorescence spectra showed that the luminescent tryptophan(s) is (are) solvent-exposed and can be quenched by I- and acrylamide but not by Cs+. On acid titration, the recombinant erythropoietin showed a conformational transition with a midpoint of pH 4.1. This suggests that the net charges on the protein moiety rather than on the whole molecule play a role in protein structure stability

  8. Radiosensitization of Chinese hamster cells by oxygen and misonidazole at low X-ray doses

    International Nuclear Information System (INIS)

    The radiosensitization of Chinese hamster V79 cells in vitro by air and misonidazole at low X-ray doses (0.2-6.0 Gy) has been studied. These survival data, with high-dose data, were fitted to the linear quadratic model ln S= -(αD + βD2), deriving estimates of α and β by six different methods to illustrate the influence of the statistical treatment on the values so derived. This study clearly demonstrated that the survival parameters α and β are dependent to some degree on the method of analysis of the raw survival data; however, their ratios, the values of oxygen enhancement ratios (OERs) and radiosensitizer enhancement ratios (SERs) derived from the different methods, are similar. All methods of analysis give reduced OERs at low radiation doses for combined low- and high-dose X-ray data. However, the OERs are still appreciably high, ranging from 2.45 to 2.50 for an oxic dose of 2 Gy. All methods of analysis gave reduced SERs at low doses for combined low and high X-ray dose data for hypoxic cells irradiated in 1 mmol dm-3 misonidazole. At survival levels corresponding to doses of 2 Gy in the presence of 1 mmol dm-3 misonidazole OERs and SERs ranged from 1.2 to 1.5. (author)

  9. Induction of stable protein-deoxyribonucleic acid adducts in Chinese hamster cell chromatin by ultraviolet light

    International Nuclear Information System (INIS)

    Ultraviolet (uv)-light-mediated formation of protein-DNA adducts in Chinese hamster cell chromatin was investigated in an attempt to compare chromatin alterations induced in vitro with those observed in vivo. Three independent methods of analysis indicated stable protein-DNA associations: a membrane filter assay which retained DNA on the filter in the presence of high salt-detergent; a Sepharose 4B column assay in which protein eluted coincident with DNA; and a CsCl density gradient equilibrium assay which showed both protein and DNA banding at densities other than their respective native densities. Treatment of the irradiated chromatin with DNase provided further evidence that protein--DNA and not protein-protein adducts were being observed in the column assay. There is a fluence-dependent response of protein-DNA adduct formation when the chromatin is irradiated at low ionic strength and is linear for protein over the range studied. When the chromatin is exposed to differing conditions of pH, ionic strength, or divalent metal ion concentration, the quantity of adduct formed upon uv irradiation varies. Susceptibility to adduct formation can be partially explained in terms of the condensation state of the chromatin and other factors such as rearrangement, denaturation, and dissociation of the chromatin components. Besides providing information on the biological significance of these types of uv-induced lesions, this technique may be useful as a probe of chromatin structure

  10. Long-term effects of tritium on cultured Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Experiments were undertaken to determine the mutagenic and chromosome-damaging effects of HTO and tritiated thymidine (3HTdR) under chronic exposure conditions. Chinese hamster ovary cells (CHO) cultured in vitro were maintained continuously for 90 days in a medium containing HTO at concentrations of 1.1-1.1x10-3 μCi/ml or 3HTdR at 4x10-1-4x10-4 μCi/ml. During the incubation period the induced gene mutations were determined for the hypoxanthineguanine phosphoribosyl transferase (HGPRT) locus, and the chromosome structural changes were analysed by standard methods. According to the experimental data the three higher concentrations of HTO and 3HTdR resulted in remarkably higher values for all mutations tested. After a 1-month exposure to the two middle concentrations, however, the frequencies showed a decreasing tendency and reached the control range after 90 days. At the lowest exposure levels no difference could be observed as compared with the controls. In the HTO series the amount of tritium 'bound firmly' to cells was measured (1-2%) and analysed biochemically; its pattern showed a uniform distribution among the cell macromolecules (DNA, RNA, protein). (author)

  11. Stable expression of human opioid receptor-like 1 in chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Objective: To stably transfect human opioid receptor-like 1 (hORL1) in Chinese hamster ovary (CHO) cells. Methods: pcDNA3.1 (+) -hORL1 was stably transfected into CHO cells by a lipofectamine based method. Transfected CHO cells were selected in culture medium containing G418. Radioligand receptor binding assay and [35S] GTPSγ binding assay were used to determine densities and functions of the expressed receptors. Results and Conclusion: hORL1 was expressed in the CHO cells. The Kd and Bmax were (0.44 ± 0.21) nmol/L and (0.35 ± 0.06) pmol/mg protein, respectively, for hORL1 in [3H] nociceptin binding assay. The EC50 of nociceptin was 3.45 nmol/L in stimulation of [35S] GTPγS binding by nociceptin.A model system of CHO cells with stable expression of hORL1 is established. (authors)

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

    International Nuclear Information System (INIS)

    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

  13. Rapid amplification system for recombinant protein production in Chinese Hamster Ovary (CHO) Cells.

    Science.gov (United States)

    Metta, M K; Kunaparaju, R K; Tantravahi, S

    2016-01-01

    Recombinant therapeutic proteins have changed the face of modern medicine in the present trend and they continue to provide innovative therapies for deadly diseases. This study describes the development of a novel stable expression system for rapid amplification of genes in Chinese Hamster Ovary (CHO) cells. The expression system consists of a host CHO cell line and an expression vector (pUB-PyOri-D-C) which encodes for Polyomavirus (Py) Origin of Replication (PyOri) for amplification of integrated genes in the presence of Py Large T Antigen (PyLT) and Dihydrofolate Reductase (DHFR) selectable marker gene for selection in the presence of Methotrexate (MTX). Use of both PyOri/PyLT and DHFR can reduce the number of rounds of selection and amplification required for isolation of high producing clones. The efficiency of pUB-PyOri-D-C was compared with that of pUB-D-C plasmid using Green fluorescent protein (GFP) and Erythropoietin (EPO) as reporter proteins. Our results showed that pUB-PyOri-D-C-EPO can help development of high expressing clone in one round of selection/amplification as compared to multiple rounds of selection/amplification with pUB-D-C-EPO plasmid. CHO-DG44/EPO clone generated using pUB-PyOri-D-C-EPO gave a productivity of 119 mg/L in shake flask. PMID:26950459

  14. Characterization of recombinant human diamine oxidase (rhDAO) produced in Chinese Hamster Ovary (CHO) cells.

    Science.gov (United States)

    Gludovacz, Elisabeth; Maresch, Daniel; Bonta, Maximilian; Szöllösi, Helen; Furtmüller, Paul G; Weik, Robert; Altmann, Friedrich; Limbeck, Andreas; Borth, Nicole; Jilma, Bernd; Boehm, Thomas

    2016-06-10

    Human diamine oxidase (hDAO) efficiently degrades polyamines and histamine. Reduced enzyme activities might cause complications during pregnancy and be involved in histamine intolerance. So far hDAO has been characterized after isolation from either native sources or the heterologous production in insect cells. Accessibility to human enzyme is limited and insect cells produce non-human glycosylation patterns that may alter its biochemical properties. We present the heterologous expression of hDAO in Chinese Hamster Ovary (CHO) cells and a three step purification protocol. Analysis of metal content using ICP-MS revealed that 93% of the active sites were occupied by copper. Topaquinone (TPQ) cofactor content was determined using phenylhydrazine titration. Ninety-four percent of DAO molecules contained TPQ and therefore the copper content at the active site was indirectly confirmed. Mass spectrometric analysis was conducted to verify sequence integrity of the protein and to assess the glycosylation profile. Electronic circular dichroism and UV-vis spectra data were used to characterize structural properties. The substrate preference and kinetic parameters were in accordance with previous publications. The establishment of a recombinant production system for hDAO enables us to generate decent amounts of protein with negligible impurities to address new scientific questions. PMID:27063138

  15. Effect of anisotonic NaCl treatment on cellular ultrastructure of V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    The ultrastructural modifications produced by anisotonic NaCl treatment of Chinese hamster mitotic cells were observed at three NaCl concentrations which have been frequently used in radiosensitization studies: 0.05, 0.5 and 1.5 M. After exposureto 0.05 M NaCl, many well-spread chromosomes are visible. The chromatin fibres are well dispersed and membraneous material is associated with the chromosomes. After hypertonic treatment with 0.5 M NaCl, the chromosomes have a uniform, structureless appearance with some coalescing into larger anaphase-like masses. At 1.5 M NaCl, large scale cellular dehydration is apparent, and filamentous structures such as microfilaments are tightly constricted. The degree of chromosome staining is also reduced below the level of the cytoplasm. After both hypo- and hypertonic NaCl treatment the chromosomes appear swollen relative to untreated cells, but hypertonic treatment causes chromosome clumping and dissociates chromatin. Conformational changes in the chromatin may restrict the capacity for DNA repair and be related to cellular radiosensitivity. (author)

  16. Electrophoretic shift mutants in Chinese hamster ovary cells: evidence for genetic diploidy

    International Nuclear Information System (INIS)

    Electrophoretic shift mutants induced in Chinese hamster ovary (CHO) cells indicate that these cells are not extensively functionally hemizygotic. Therefore, effective haploidy is unsatisfactory as a general theory to explain the frequency of recessive mutants in this cell line. CHO cells were screened for electrophoretic shift variants of enzymes coded by approximately 40 genetic loci. Clones isolated after exposure to ultraviolet radiation were examined by starch gel and Cellogel electrophoresis. Shift variants were recovered for enzymes representing 11 different loci. Variant clones were subcloned to demonstrate the heritability of the variations. Mutants at nine loci produced multiple-banded patterns consistent with the patterns expected of genes at loci represented twice (diploid). Chromosome localization of these diploid loci in other mammalian species where they have been mapped, suggests that they represent a random sample of CHO genes. Chromosome analysis of mutant subclones indicated that the variation did not take place in tetraploid cells. The data indicate that the quasi-diploid CHO cells appear only as functionally hemizygous as would be expected of a slightly hypodiploid cell line derived from an organism in which the haploid number is 11

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Tsutomu; Shimada, Yuji; Kamata, Rikisaburo (Nihon Univ., Tokyo (Japan). School of Medicine)

    1989-10-01

    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 5mug/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 mug/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).

  19. A Chinese hamster ovary cell line hypersensitive to ionizing radiation and deficient in repair replication

    International Nuclear Information System (INIS)

    An X-ray-sensitive Chinese hamster ovary cell line was isolated by means of a semi-automated procedure in which mutagenized cells formed colonies on top of agar, were X-irradiated, and were photographed at two later times. The author compared the photographs to identify colonies that displayed significant growth arrest. One of the colonies identified in this manner produced a stable line (irs1SF) that is hypersensitive to ionizing radiation. irs1SF performs only half as much X-ray-induced repair replication as the parental line, indicating a defect in excision repair. This defect is believed to be the primary cause of the line's radiosensitivity. Although irs1SF repairs DNA double-strand breaks at a normal rate, it repairs single-strand breaks more slowly than normal. irs1SF has an elevated number of spontaneous chromatid aberrations and produces significantly higher numbers of X-ray-induced chromatid aberrations after exposure during the G1 phase of the cell cycle. The line is hypomutable, with X-ray exposure inducing only one-third as many 6-thioguanine-resistant colonies as the parental line. 45 refs.; 10 figs.; 1 table

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  3. Recovery of subchromosomal DNA synthesis in synchronous V-79 Chinese hamster cells after ultraviolet light exposure

    International Nuclear Information System (INIS)

    Previous work obtained from Chinese hamster V-79 cells indicated that, immediately following exposure, UV-induced lesions acted as blocks to elongation of nascent strands, but gradually lost that ability over a 10 h period after exposure to 10 J/m2. The work reported herein attempted to examine possible cell cycle mediated alterations in the recovery of DNA synthesis. Kinetic incorporation of radiolabeled thymidine studies indicated that there may have been a more rapid recover of DNA synthesis in cells irradiated in G1 or G2 vs cells irradiated in S phase. DNA fiber autoradiograms prepared from synchronous cells indicated that after irradiation in any phase of the cell cycle, the length of newly synthesized DNA was equal to control lengths 1 h after exposure to 5.0Jm2 (or 1 h after entering S phase for cells irradiated in G1 or G2). This observed recovery was not solely due to an excision process. No cell cycle mediated difference in the number of dimers induced or removed as a function of cell cycle position was observed. These results appear to be consistent with a continuum of effects, with initiation effects dominating the response at low fluences, gapped synthesis at intermediate fluences and elongation inhibition at high fluences. The fluences at which each event dominates may be cell-line specific. (author)

  4. Large scale isolation of DNA repair mutants of Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    A semiautomated procedure has been designed and used successfully to permit the isolation of a large number of uv (ultraviolet light) sensitive mutant colonies of Chinese hamster ovary (CHO) cells. 149 uv sensitive mutants of CHO cells have been isolated to date by this procedure. This represents the largest in vitro isolation to date of uv sensitive mutants of mammalian cells The isolation of uv sensitive clones of EM9-1 represents the first stepwise isolation of double mutants of mammalian cells with sensitivity to an increased range of carcinogenic agents. Using a rapid screening test for complementation group assignment, 70 of these mutants have been assigned to a total of 5 complementation classes. Representatives of 4 of these classes have been studied for competence in repair replication following uv irradiation and have demonstrated a defective phenotype in uv repair. Representatives of 2 of these repair-deficient classes have been studies for uv mutagenic response for three selective markers, and have demonstrated an approximately ninefold enhancement in mutant yield per unit uv exposure relative to the parental cels. The sensitivity, repair phenotype, and mutational response ofthe isolates studied resemble that of human mutant xeroderma pigmentosum cells

  5. Recovery kinetics from radiation and hyperthermia damage to cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    The recovery kinetics from the damage resulting from combination treatments of X-irradiation and 42 degrees and 44 degrees C hyperthermia were analyzed in Chinese hamster V79 cells. The survival of cells attained to the additive level, when either 42 degrees C hyperthermia or 42 degrees C hyperthermia and X-irradiation was given as the first treatment, followed by a 3- to 4-hour interval at 37 degrees C with combined treatments of X-irradiation and 42 degrees - 44 degrees C sequential hyperthermia. The survival of cells attained to the additive level when X-irradiation or 44 degrees C hyperthermia, or both, were given as the first treatment followed by a 5- to 7-hour interval in the combined treatments of X-irradiation and 44 degrees - 42 degrees C sequence. However, when the combined hyperthermia of 44 degrees - 42 degrees C sequence was given as the first treatment, the survival of cells did not attain the additive level within a 24-hour interval at 37 degrees C. From these results, researchers believe the damage induced by the combined hyperthermia of the 44 degrees - 42 degrees C sequence was retained partially in the cells during at least a 24-hour interval at 37 degrees C and may interact synergistically with the damage by the subsequent X-irradiation

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

    International Nuclear Information System (INIS)

    The subject matter of this investigation concerns the killing and mutagenic effects induced by far-UV radiation and broad spectra of black, white and gold lights. Applying radiation directly on CHO (Chinese hamster ovary) 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 (6TG), ouabain and diptheria toxin (DT). Cells in the G1/early S boundary are the most sensitive to far-UV or unfiltered fluorescent lights. When synchronous cells are irradiated with moderate doses of far-UV or unfiltered broad spectra of black light, mutations to 6-TG and ouabain resistance are slightly higher in early S period than in the remaining parts of the cell cycle. Mutation induction of 6-TG, ouabain or DT resistance is increased in the split-dose samples of the asynchronous and synchronous CHO cells. CHO cells predominantly express an error-prone repair mechanism after photoirradiation

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

    International Nuclear Information System (INIS)

    Potassium ion influx was measured by monitoring 42KCl 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+

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

    International Nuclear Information System (INIS)

    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. 31P NMR analysis of membrane phospholipid organization in viable, reversibly electropermeabilized Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Chinese hamster ovary (CHO) cells were reversibly permeabilized by submitting them to short, high-intensity, square wave pulses (1.8 kV/cm, 100 μs). The cells remained in a permeable state without loss of viability for several hours at 40C. A new anisotropic peak with respect to control cells was observed on 31P NMR spectroscopic analysis of the phospholipid components. This peak is only present when the cells are permeable, and normal anisotropy is recovered after resealing. Taking into account the fusogenicity of electropermeabilized cells, comparative studies were performed on 5% poly(ethylene glycol) treated cells. The 31P NMR spectra of the phospholipids displayed the same anisotropic peak as in the case of the electropermeabilized cells. In the two cases, this anisotropic peak was located downfield from the main peak associated to the phospholipids when organized in bilayers. The localization of this anisotropic peak is very different from the one of a hexagonal phase. The authors proposed a reorganization of the polar head group region leading to a weakening of the hydration layer to account for these observations. This was also thought to explain the electric field induced fusogenicity of these cells

  10. Genotoxic Effects of PAH Containing Sludge Extracts in Chinese Hamster Ovary Cell Cultures

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective Many studies have been conducted in order to evaluate the genotoxicity of chemicals and waste materials, which utilized in vivo test protocols. The use of animals for routine toxicity testing is now questioned by a growing segment of society[1]. Methods Keeping the above fact in mind, we have conducted in the present study the genotoxicity evaluation of oily sludge samples generated from a petroleum refinery and petrochemical industry and ETP sludge from petroleum refinery using DNA damage, chromosomal aberration, p53 protein induction and apoptosis in short term in vitro mammalian Chinese Hamster Ovary cell cultures. Results It is evident from the results that the oily sludge compounds derived from petroleum refinery and petrochemical industry could cause DNA damage, chromosomal aberration, p53 protein accumulation and apoptotic cell death on exposure to oily sludge extracts in the presence of metabolic activation system (S-9 mix), however, ETP sludge extract could not cause significant genotoxicity in comparison to oily sludge extract and negative control. Conclusion The effect may be attributed to polycyclic aromatic hydrocarbons present in the samples as evidenced from GC-MS.

  11. 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,...... for analysis and engineering of industrially relevant CHO cells. Full implementation of such tools for generating specifically engineered CHO production cell lines may allow significant cost-reductions in production of complex biopharmaceuticals such as FVIII....... using omics tools. A wide range of methods were applied including whole-genome sequencing, targeted genome sequencing, mRNA sequencing, miRNA sequencing and mass spectrometry based shotgun proteomics on a number of clones in order to get a more holistic picture of the inner workings of these CHO...... further lead to degradation of FVIII by the endoplasmic-reticulum-associated protein degradation pathway. This is to our knowledge, the first time that such extensive omics tools have been applied to a broad panel of CHO cells producing a very complex protein. The holistic view obtained for the FVIII...

  12. Interaction of hyperthermia and radiation on the induction of division delay in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The mitotic selection procedure for cell cycle analysis was used in the investigation of the interaction of hyperthermia and ionizing radiation on the induction and duration of division delay in Chinese hamster ovary cells. Hyperthermia (immersion in a 45 degrees C water bath) produced a blockade of cell cycle progression with a transition point in late G2-early M, approximately at the X-ray transition point (35 min prior to selection). The duration of division delay for heated cells depended on the time of immersion: 24 minutes/minute at 45 degrees C. Radiation-induced division delay occurred at a rate of 45 minutes/gray of X-irradiation. When hyperthermic exposure and X-irradiation were combined with less than 1 minute between treatments, a division delay resulted that was approximately the sum of the delays produced by the individual treatments. As the interval between treatments was increased, the overall division delay also increased beyond that which could be accounted for solely by the postponement of the second treatment. These results indicate that hyperthermia and radiation induce division delay by different mechanisms

  13. Intracellular trafficking of recycling apolipoprotein E in Chinese hamster ovary cells.

    Science.gov (United States)

    Braun, Nicole A; Mohler, Peter J; Weisgraber, Karl H; Hasty, Alyssa H; Linton, MacRae F; Yancey, Patricia G; Su, Yan Ru; Fazio, Sergio; Swift, Larry L

    2006-06-01

    We have investigated apolipoprotein E (apoE) recycling in Chinese hamster ovary (CHO) cells, a peripheral cell that does not produce lipoproteins or express apoE. Using a pulse-chase protocol in which cells were pulsed with 125I-apoE-VLDL and chased for different periods, approximately 30% of the apoE internalized during the pulse was resecreted within a 4 h chase in a relatively lipid-free state. The addition of lysosomotropic agents or brefeldin A had no effect on apoE recycling. Unlike previous results with hepatocytes and macrophages, neither apoA-I nor upregulation of ABCA1 stimulated apoE recycling. However, cyclodextrin, which extracts cholesterol from plasma membrane lipid rafts, increased recycling. Confocal studies revealed that apoE, internalized during a 1 h pulse, colocalizes with early endosomal antigen-1, Rab5, Rab11a, and lysobisphosphatidic acid but not with lysosomal-associated membrane protein-1. Colocalization of apoE and Rab11a persisted even after cells had been chased for 1 h, suggesting a pool of apoE within the endosomal recycling compartment (ERC). Our data suggest that apoE recycling in CHO cells is linked to cellular cholesterol removal via the ERC and phospholipid-containing acceptors in a pathway alternative to the ABCA1-apoA-I axis. PMID:16534141

  14. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    LIQiang; ZHOUGuang-Ming; 等

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accelerated carbon ions with linear energy transfers of 125.5,200 and 700keV/um were measured,respectively,Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves.They are 7.86±0.17,10.44±1.11 and 32.32±3.59um2 in turn.With the surviving response of V79 cells to 60Co γ-rays as a reference value,relative biological effectiveness at 10%,20%,50%and 80% survival levels were given for the accelerated carbon ions,The results showed that carbon ions with LET of 125.5keV/um had a higher value of RBE at all the four survival levels than the carbon ions with other LETs.It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200keV/um for carbon ions.

  15. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accclerated carbon ions with linear energy transfers of 125.5, 200 and 700 keV/μm were measured, respectively. Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves. They are 7.86±0.17, 10.44±1.11 and 32.32±3.58 μm2 in turn. With the surviving response of V79 cells to 60Co γ-rays as a reference value, relative biological effectiveness at 10%, 20%, 50% and 80% survival levels were given for the accelerated carbon ions. The results showed that carbon ions with LET of 125.5 keV/μm had a higher value of RBE at all the four survival levels than the carbon ions with other LETs. It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200 keV/μm for carbon ions.

  16. Characterization of ultraviolet light-induced ouabain-resistant mutations in Chinese hamster cells

    International Nuclear Information System (INIS)

    Ouabain-resistant mutations in Chinese hamster cells have been quantitatively characterized. The mutation frequencies were found to be induced curvilinearly with treatments of increasing doses of ultraviolet light (UV). For the range of UV doses tested (5-20 J/m2), the observed mutation frequency, Y, as a function of UV dose X, follows a curvilinear function, Y=(-28+13.37X - 1.52X2+0.08 X3).10-6. The frequencies of UV-induced mutations were directly correlated with cell survival, indicating a similar causal relationship between cell killing and mutation induction. Under the same experimental conditions, X-rays induced 6-thioguanine-, but not ouabain-, resistant mutations, UV-induced ouabain-resistant (ouasup(r)) mutants exhibit a selection disadvantage. Their phenotypic expressions are modifiable by various agents. Wild type and 16 ouasup(r) mutants were compared with respect to their sensitivity to ouabain inhibition of 86Rb uptake by whole cells. All the ouasup(r) mutants assayed are less sensitive to the drug than are wild-type cells. In the absence of ouabain, the Na+-K+-ATPase activities can be significantly higher or lower than that of the wild-type cells. (Auth.)

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

    International Nuclear Information System (INIS)

    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 G1-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 G1-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.)

  18. 12-O-Tetradecanoyl-phorbol-13-acetate and its relationship to SCE induction in Syrian and Chinese hamster cells

    International Nuclear Information System (INIS)

    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

  19. 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)

    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

  20. Distribution of radiation-induced G1 exchange and terminal deletion breakpoints in Chinese hamster chromosomes as detected by G banding

    International Nuclear Information System (INIS)

    A total of 255 chromosomal aberrations induced by X-rays in G1 phase of the cell cycle were scored in 600 G-banded metaphases prepared from Chinese hamster female cells. On the basis of a detailed analysis of these aberrations a total of 441 chromosomal breakpoints were mapped to the individual Chinese hamster chromosomes and their bands. More breakpoints were mapped to G-light (80.5%) than to G-dark (19.5%) bands. These results indicate that radiation-induced exchange and terminal deletion breakpoints, as observed in the first postirradiation metaphase, have different patterns of distribution in Chinese hamster chromosomes. Clustering of terminal deletions in the long arms of X chromosomes, which are entirely occupied by heterochromatin, suggests that chromosomal repair mechanisms responsible for rejoining of chromosomal breaks are less effective in heterochromatic than in other genomic regions. (author)

  1. Removal of radiation damage by subpopulations of plateau-phase Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Specific cellular radiobiology studies are often required to test aspects of the mathematical models developed in the Radiation Dosimetry program. These studies are designed to determine whether specific mathematical expressions, which characterize the expected effect of biochemical mechanisms on observable biological responses, are consistent with the behavior of selected cell lines. Since these tests place stringent requirements on the cellular system, special techniques and culture conditions are required to minimize biological variability. The use of specialized cell populations is providing data on the extent of repair following low doses, and on the changes in the types of damage that can be repaired as the cell progresses toward mitosis. The stationary-phase Chinese hamster ovary (CHO) cells are composed primarily of G(1)-phase cells (83%), with the remainder comprising both G(2) and S phases. Removal of radiation damage by cells was studied in split-dose experiments. To date, we have observed no significant differences in cellular repair rate. This suggests, therefore, that each of the repair processes found in stationary-phase cells is cell-age independent. However, cellular radiation sensitivity does change rapidly and considerably as the cells progress from one phase to the next through the cell cycle. Since the rate of damage removal appears invariant, the change in survival must reflect the efficiency of producing that damage. The experimental data suggest that production of one or another sort of damage probably dominates during specific phases of the cell cycle, while the capacity for removal of all types of damage remains relatively constant

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

    International Nuclear Information System (INIS)

    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 32Pi and L-[U-14C]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

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

    International Nuclear Information System (INIS)

    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

  4. Radiation Survival in Synchronous and Asynchronous Chinese Hamster Cells In Vitro

    International Nuclear Information System (INIS)

    Synchronized mammalian cells enable radiation responses to be examined as a function of the position of the cell within its generation cycle. However, synchrony techniques are limited by the random distribution of generation rates in cell populations and, because of the techniques employed, stages such as G2 and mitosis are difficult to examine. Superposing on the mitotic selection technique high-specific- activity tritiated thymidine to inactivate resistant S cells enables the average sensitivity of G2 and mitotic cells to be established. The changes in sensitivity during the cell cycle for Chinese hamster cells are considerable, at least as great as the effect of the presence or absence of oxygen. G2 and mitosis are the most sensitive cells, followed by G1, early S and finally late S cells as the most resistant. With this data the response of an asynchronous population can be estimated and compared with experimental data. Calculation and experiment agree well. The selection + tritiated thymidine technique is still limited in resolution to a one-hour period. Experiments varying the interval between irradiation and selection indicate that there is, very probably, a brief phase more sensitive than the average in the selected mitotic population which should be examined further. Experiments with Janus (fission) neutrons indicate that the changes in response during the cell cycle are smaller than for X-rays and the shapes of the survival curves are different. The RBE of these neutrons is shown to vary with both dose level and position in the cell cycle. (author)

  5. 5-Azacytidine Induces Transgene Silencing by DNA Methylation in Chinese Hamster Cells

    Science.gov (United States)

    Broday, Limor; Lee, Yong-Woo; Costa, Max

    1999-01-01

    The cytosine analog 5-azacytidine (5-AzaC) is a demethylating agent that is also known to induce mutagenesis in mammalian cells. In this study, the mutagenic potential of this drug was tested in the G10 and G12 transgenic Chinese hamster cell lines, which have a single bacterial gpt gene integrated into the genome at different sites, with its expression driven by a simian virus 40 (SV40) promoter. We show that the mutation frequencies following a 48-h exposure to different concentrations of 5-AzaC were 10 to 20 times higher than those of any of the other numerous mutagens that have been tested in the G10-G12 system. Moreover, the mutation frequencies were much higher in the G10 cell line than in the G12 cells. Detailed molecular analysis of the 6-thioguanine (6-TG)-resistant variants demonstrated that transgene silencing by de novo DNA methylation and increased chromatin condensation in the SV40 promoter was the major factor responsible for this high level of 6-TG resistance. As would be expected, exposure to 5-AzaC lowered the overall genomic DNA methylation levels, but it unexpectedly caused hypermethylation and increased chromatin condensation of the transgene in both the G10 and G12 cell lines. These results provide the first evidence that 5-AzaC may also induce transgene-specific DNA methylation, a phenomenon that can further be used for the elucidation of the mechanism that controls silencing of foreign DNA. PMID:10082586

  6. Bioactivation of mitomycin antibiotics by aerobic and hypoxic Chinese hamster ovary cells overexpressing DT-diaphorase.

    Science.gov (United States)

    Belcourt, M F; Hodnick, W F; Rockwell, S; Sartorelli, A C

    1996-06-28

    DT-Diaphorase catalyzes a two-electron reduction of mitomycin C (MC) and porfiromycin (POR) to reactive species. Many cell lines that overexpress DT-diaphorase and are sensitive to the mitomycins are protected from the aerobic cytotoxicity of these drugs by the DT-diaphorase inhibitor dicumarol. The cytoprotective properties of this relatively non-specific inhibitor, however, vanish under hypoxic conditions. To ascertain the role of DT-diaphorase in mitomycin bioactivation and cytotoxicity in living cells, a rat liver DT-diaphorase cDNA was transfected into Chinese hamster ovary cells. MC was equitoxic to the parental cells under oxygenated and hypoxic conditions. In contrast, POR was less toxic than MC to these cells under aerobic conditions, but significantly more toxic than MC under hypoxia. Two DT-diaphorase-transfected clones displayed increases in DT-diaphorase activity of 126- and 133-fold over parental cells. The activities of other oxidoreductases implicated in mitomycin bioreduction were unchanged. MC was more toxic to both DT-diaphorase-transfected lines than to parental cells; the toxicity of MC to the transfected lines was similar in air and hypoxia. POR was also more toxic to the DT-diaphorase-elevated clones than to parental cells under oxygenated conditions. Under hypoxia, however, the toxicity of POR to the transfected clones was unchanged from that of parental cells. The findings implicate DT-diaphorase in mitomycin bioactivation in living cells, but suggest that this enzyme does not contribute to the differential toxicity of MC or POR in air and hypoxia. PMID:8687482

  7. Defective DNA cross-link removal in Chinese hamster cell mutants hypersensitive to bifunctional alkylating agents

    International Nuclear Information System (INIS)

    DNA repair-deficient mutants from five genetic complementation groups isolated previously from Chinese hamster cells were assayed for survival after exposure to the bifunctional alkylating agents mitomycin C or diepoxybutane. Groups 1, 3, and 5 exhibited 1.6- to 3-fold hypersensitivity compared to the wild-type cells, whereas Groups 2 and 4 exhibited extraordinary hypersensitivity. Mutants from Groups 1 and 2 were exposed to 22 other bifunctional alkylating agents in a rapid assay that compared cytotoxicity of the mutants to the wild-type parental strain, AA8. With all but two of the compounds, the Group 2 mutant (UV4) was 15- to 60-fold more sensitive than AA8 or the Group 1 mutant (UV5). UV4 showed only 6-fold hypersensitivity to quinacrine mustard. Alkaline elution measurements showed that this compound produced few DNA interstrand cross-links but numerous strand breaks. Therefore, the extreme hypersensitivity of mutants from Groups 2 and 4 appeared specific for compounds the main cytotoxic lesions of which were DNA cross-links. Mutant UV5 was only 1- to 4-fold hypersensitive to all the compounds. Although the initial number of cross-links was similar for the three cell lines, the efficiency of removal of cross-links was lowest in UV4 and intermediate in UV5. These results suggest that the different levels of sensitivity are specifically related to different efficiencies of DNA cross-link removal. The phenotype of hypersensitivity to both UV radiation and cross-link damage exhibited by the mutants in Groups 2 and 4 appears to differ from those of the known human DNA repair syndromes

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

    International Nuclear Information System (INIS)

    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 D0 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.)

  9. Effects of selenocystine on lead-exposed Chinese hamster ovary (CHO) and PC-12 cells

    International Nuclear Information System (INIS)

    Lead is a pervasive environmental toxin that affects multiple organ systems, including the nervous, renal, reproductive, and hematological systems. Even though it is probably the most studied toxic metal, some of the symptoms of lead toxicity still cannot be explained by known molecular mechanisms. Therefore, lead-induced oxidative stress has recently started to gain attention. This in vitro study confirms the existence of oxidative stress due to lead exposure. Administration of lead acetate (PbA) to cultures of Chinese hamster ovary cells (CHO) had a concentration-dependent inhibitory effect on colony formation and cell proliferation. This inhibition was eliminated by 5 μM selenocystine (SeCys). In order to evaluate the nature of SeCys's effect, we measured glutathione (GSH), its oxidized form glutathione disulfide (GSSG), malondialdehyde (MDA), catalase, and GSH peroxidase (GPx) activities in lead-exposed CHO cells both in the presence and absence of SeCys. Increases in MDA, catalase, and GPx activities were observed in cultures that received only PbA, but supplementation with SeCys returned these measures to pretreatment levels. The ratio of GSH to GSSG increased in lead-exposed cells incubated in SeCys-enhanced media but declined in cultures treated with PbA only. In order to determine whether SeCys also reverses lead-induced neurotoxicity, a neuronal cell line, PC-12 cells, was used. Lead's inhibition on neurite formation was significantly eliminated by SeCys in PC-12 cells. Our results suggest that SeCys can confer protection against lead-induced toxicity in CHO cells and neurotoxicity in PC-12 cells

  10. Metabolic analysis of antibody producing Chinese hamster ovary cell culture under different stresses conditions.

    Science.gov (United States)

    Badsha, Md Bahadur; Kurata, Hiroyuki; Onitsuka, Masayoshi; Oga, Takushi; Omasa, Takeshi

    2016-07-01

    Chinese hamster ovary (CHO) cells are commonly used as the host cell lines concerning their ability to produce therapeutic proteins with complex post-translational modifications. In this study, we have investigated the time course extra- and intracellular metabolome data of the CHO-K1 cell line, under a control and stress conditions. The addition of NaCl and trehalose greatly suppressed cell growth, where the maximum viable cell density of NaCl and trehalose cultures were 2.2-fold and 2.8-fold less than that of a control culture. Contrariwise, the antibody production of both the NaCl and trehalose cultures was sustained for a longer time to surpass that of the control culture. The NaCl and trehalose cultures showed relatively similar dynamics of cell growth, antibody production, and substrate/product concentrations, while they indicated different dynamics from the control culture. The principal component analysis of extra- and intracellular metabolome dynamics indicated that their dynamic behaviors were consistent with biological functions. The qualitative pattern matching classification and hierarchical clustering analyses for the intracellular metabolome identified the metabolite clusters whose dynamic behaviors depend on NaCl and trehalose. The volcano plot revealed several reporter metabolites whose dynamics greatly change between in the NaCl and trehalose cultures. The elastic net identified some critical, intracellular metabolites that are distinct between the NaCl and trehalose. While a relatively small number of intracellular metabolites related to the cell growth, glucose, glutamine, lactate and ammonium ion concentrations, the mechanism of antibody production was suggested to be very complicated or not to be explained by elastic net regression analysis. PMID:26803706

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

    OpenAIRE

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

    1990-01-01

    We 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 (FAO; EC 1.1.1.192) activity, which catalyzes the oxidation of hexadecanol to hexadecanoic acid, although the intermediate...

  12. Onderzoek naar de inductie van chromosoomafwijkingen en "sister- chromatid exchanges" door methecrylamide met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1987-01-01

    Methacrylamide is onderzocht in een test op chromosoomafwijkingen en een test op zuster-chromatide uitwisselingen (SCE's) in V79 Chinese hamster cellen in vitro ; vanwege lage toxiciteit konden hoge concentraties (tot 10 mg/ml, 117,4 mmol/l) worden getest. Methacrylamide induceerde een significate, concentratie gerelateerde toename in het aantal SCE's per cel vanaf 2,5 mg/ml (29,4 mmol/l) zowel in aan- als in afwezigheid van metabolische activering. Daarentegen zijn er onvoldoende a...

  13. Onderzoek naar de inductie van chromosoomafwijkingen en "sister- chromatid exchanges" door methylmethacrylaat met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1986-01-01

    Methylmethacrylaat of methacrylzure-methyl-ester bleek een clastogene werking te hebben in een test op chromosoomafwijkingen met Chinese hamster cellen in vitro, zowel in afwezigheid van een systeem voor metabolische activering (S9), bij concentraties vanaf 3 ul/ml 28,2 mmol/l), als in aanwezigheid van metabolische activering (S9) bij concentraties vanaf 2 ul/ml (18,8 mmol/l). Tevens induceerde methylmethacrylaat in deze cellen een significante toename in het aantal zuster-chromatide uitwisse...

  14. Onderzoek naar de inductie van chromosoomafwijkingen en "sister- chromatid exchanges" door acrylamide met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1986-01-01

    Acrylamide bleek een clastogene werking te hebben in een test op chromosoomafwijkingen met Chinese hamster cellen in vitro vanaf 0,1 mg/ml (1,4 mmol/l), zowel in aan- als afwezigheid van een systeem voor metaboliosche activering (S9). Tevens induceerde acrylamide in deze cellen een significante toename in het aantal zuster-chromatide uitwisselingen (SCE's) per cel, zowel in aan- als afwezigheid van een systeem voor metabolische activering (S9) bij concentraties van 0,6 en 1 mg/ml (respec...

  15. 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)

    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

  16. Influence of irradiation at different stages of mitotic cycle unon production of sister chromatid exchanges in cultured chinese hamster cells

    International Nuclear Information System (INIS)

    Frequency of.sister chromatid exchanges (SCE) and microexchanges in the chinese hamster cells was investigated by means of the method of differential colouring of chromatids on irradiation at different stages of the mitotic cycle. It is shown that the irradiation increases frequency of SCE and microexchanges if it is performed before the end of the replicative DNA synthesis. Comparison of frequency dependence of radiation-induced microexchanges and SCE at different stages of the mitotic cycle permits to conclude that the microexchanges are small SCE

  17. The cytogenetic effect of radiation and postirradiation treatment of Chinese hamster cells with arabinoside cytosine and hydroxyurea

    International Nuclear Information System (INIS)

    A two-hour treatment of Chinese hamster cells at the G1 stage of the cell cycle with arabinoside cytocine combined with hydroxyurea after X-irradiation (50-300 cGy) produced a 2- to 4-fold increase in the frequency of chromosome aberrations. The mitotic selection method was used to synchronize the cells. The potentiating effect of inhibitors was estimated by the yield of centric exchanges decreased with increasing radiation dose. It is suggested that DNA repair processes determining a linear component of the dose-response curve are modified within the dose-range under study

  18. Permeabilization of ultraviolet-irradiated chinese hamster cells with polyethylene glycol and introduction of ultraviolet endonuclease from Micrococcus luteus

    International Nuclear Information System (INIS)

    Chinese hamster V-79 cells were made permeable by treatment with polyethylene glycol and then incubated with a Micrococcus luteus extract containing ultraviolet-specific endonuclease activity. This treatment introduced nicks in irradiated, but not in unirradiated, deoxyribonucleic acid. The nicks remained open for at least 3 h; there was no loss of endonuclease-sensitive sites, and no excision of dimers as measured by chromatography was detected. In addition, there was no increase in ultraviolet resistance in treated cells. This suggests that the absence of a significant amount of excision repair in rodent cells is due to the lack of both incision and excision capacity

  19. The subcellular distribution of 239Pu, 241Am and 59Fe in the liver of rat and Chinese hamster as dependent on time

    International Nuclear Information System (INIS)

    The subcellular distribution of monomeric 239Pu, 241Am and iron in rat and Chinese hamster liver has been investigated by sucrose-, metrizamide- and Percoll-density gradients. In rat liver, the transuranium elements become and remain bound to typical lysosomes up to several months after incorporation. Lysosomes are also the primary storage organelle in Chinese hamster liver. However, their apparent density in sucrose decreases with time, which possibly indicates transition into telolysomes. The transuranium nuclides show a subcellular distribution which is quite different from that of iron. (orig.)

  20. [Experimental therapy in Chinese hamsters and rats infected with larval Echinococcus multilocularis by using mebendazole, albendazole and ivermectin with brief review of chemotherapy of human multilocular echinococcosis].

    Science.gov (United States)

    Inaoka, T; Nakao, M; Ohnishi, K; Kutsumi, H

    1987-01-01

    The effects of the mebendazole, albendazole and ivermectin on secondary multilocular echinococcosis in Chinese hamsters infected with intraperitoneal inoculation of protoscolices and in rats infected with transportal inoculation of protoscolices were investigated. A reduction in weight of the hydatids greater than 95% was recorded in Chinese hamsters intraperitoneally injected with mebendazole suspension. Oral administration of mebendazole moderately inhibited the development of the hydatids. Albendazole was less effective than mebendazole. Ivermectin was ineffective. The treatment with mebendazole of larval E. multilocularis inhibited the growth of the hydatids but it could not completely kill the parasite tissues. The present status of chemotherapy of the human multilocular echinococcosis was briefly discussed. PMID:3546045

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

    International Nuclear Information System (INIS)

    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)

  2. Amplification of SV40 and cellular genes in SV40 transformed Chinese hamster embryo cells treated with chemical carcinogens

    International Nuclear Information System (INIS)

    To study the effect of chemical carcinogens on the amplification of specific genes, we have constructed a model system, utilizing integrated SV40 as an example for an endogenous gene. Recently, we have shown that exposure of SV40 transformed Chinese hamster cells to a variety of carcinogens induced the amplification of the integrated SV40 genome. Functional T-antigen was necessary for the amplification phenomenon. The work presented in this manuscript shows that the functional origin of replication, which consists of the sequences at the origin of replication and an active T-antigen, is required for the amplification. Utilizing cloned SV40 inserts and the adjacent Chinese hamster sequences we were able to show that SV40 and the flanking cellular sequences were amplified. As the distance from the SV40 origin of replication increased, the extent of amplification was decreased. The amplified sequences are associated with both chromosomal and extrachromosomal sequences. Carcinogen-mediated amplification is not restricted to SV40 sequences and endogenous genes such as dehydrofolate reductase (dhfr), the histocompatibility gene (HLA) and c-ras/sup Ha/ gene are amplified. 26 references, 5 figures

  3. 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

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

    International Nuclear Information System (INIS)

    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 μg/ml) and 5-fluorodeoxyuridine (0.1 μg/ml). The results confirm that cells irradiated in early G1 phase experience a delay in their entry into S phase. This G1 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 G1/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 G1 block, which reduces the overall number of cells in S phase after irradiation

  5. 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 of...

  6. COMPARISON OF THE TOXICITY OF ACRYLAMIDE, CYCLOPHOSPHAMIDE, CHLRODECONE, AND DIETHYLSTILBESTROL IN CHINESE HAMSTER OVARY (CHO) CELLS WITH THEIR TOXICITY IN VIVO

    Science.gov (United States)

    In order to compare in vitro toxicity with in vivo toxicity, four chemicals that have been tested in the in vivo/in vitro toxicological screen proposed by the Health Effects Research Laboratory, EPA were tested in a Chinese Hamster Ovary (CHO) cytotoxicity assay. Viability index,...

  7. Influence of heterogenous alpha irradiation of Chinese hamster liver on survival and the induction of cancer. IV

    International Nuclear Information System (INIS)

    Estimation of risk to the human liver from deposited alpha-emitting radionuclides currently is based on epidemiological data accumulated from patients that received injections of the X-ray contrast medium Thorotrast. These exposures resulted in highly focal distributions of radiation dose, primarily around the liver sinusoids. It is, important to understand the applicability of these human data for extrapolating risk to people that are exposed to other liver-seeking alpha emitters, such as plutonium (Pu), where the distribution of alpha dose may be much more uniform and uncomplicated by the presence of large colloid masses in the liver tissue. In this study, Chinese hamsters received intravenous injections of Thorotrast (7.4, 1.5 or 0.30 Bq/g body weight) or monomeric 239Pu citrate (7.4 Bq/g), and were held for life-span observation. Using Cox proportional hazards analysis of the dose response for several neoplastic and hyperplastic lesions observed in the liver, it was found that the relative risk for each endpoint was increased in a dose related manner for all three dose levels of Thorotrast, and that the risks for the Pu-injected animals (7.4 Bq/g) were similar to those of the hamsters injected with 1.5 Bq/g Thorotrast. Dosimetry and pathological analyses are being continued to examine the dose-response relationships for these two patterns of alpha irradiation in greater detail, particularly as they affect the liver. (author)

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

    International Nuclear Information System (INIS)

    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.

  9. Ethanol and acetaldehyde potentiate the clastogenicity of ultraviolet light, methol methanesulfonate, mitomycin C and bleomycin in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Ethanol itself did not induce any apparent chromosome aberrations in Chinese hamster ovary cells. However, posttreatment with ethanol potentiated the chromosome aberrations induced by ultraviolet light (UV), methyl methanesulfonate (MMS), mitomycin C (MMC) or bleomycin (BLM). Chromatid exchanges were predominantly increased in cultures treated with UV, MMS or MMC and then with ethanol, whereas chromosome breaks and chromatid exchange were the major types of aberrations increased in the cultures treated with BLM and ethanol. Posttreatment with acetaldehyde, the major metabolite of ethanol, also potentiated the chromosome aberrations induced by UV, MMS, MMC or BLM. The main types of aberrations potentiated by posttreatment with acetaldehyde were similar to those by posttreatment with ethanol. (author). 32 refs.; 3 figs.; 2 tabs

  10. 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.

  11. An inhibitory factor for cell-free protein synthesis from Salmonella enteritidis exhibits cytopathic activity against Chinese hamster ovary cells.

    Science.gov (United States)

    Iwamaru, Y; Miyake, M; Arii, J; Tanabe, Y; Noda, M

    2001-12-01

    A factor inhibiting cell-free protein synthesis was purified from Salmonella enteritidis cell lysate by sequential ammonium sulfate precipitation, chromatography on anion exchange and hydrophobic interaction columns, and polyacrylamide disc gel electrophoresis. The purified factor, which was named SIPS (Salmonella inhibitor of protein synthesis), inhibited in vitro protein synthesis in rabbit reticulocyte lysate and had a molecular mass of 38 kDa, estimated by PAGE under denaturing conditions. SIPS was also cytopathic for Chinese hamster ovary cells. The N-terminal amino acid sequence (20 residues) of SIPS was found to be identical to that of mature L-asparaginase II of Escherichia coli. Indeed, the purified SIPS exhibited asparaginase activity, E. coli L-asparaginase II had cytopathic activity and inhibited in vitro protein synthesis. The results suggest that at least a part of cytotoxicity and inhibition of cell-free protein synthesis caused by S. enteritidis is a property of the bacterial L-asparaginase. PMID:11747376

  12. The radioprotective effect of L-NAME inhibitor of NO-synthase in Chinese hamster cells in culture

    International Nuclear Information System (INIS)

    Radioprotective effect of L-NAME - one of the inhibitors of NO-synthase - was estimated by the yield of the aberrant anaphases after exposure of Chinese hamster cells to different doses of γ-rays and β-particles. Decrease of the frequency of radiation-induced chromosome aberrations was observed during LNAME cell treatment before irradiation (1-4 h) only. 3 Gy dose without LNAME and 6 Gy dose with L-NAME were equieffective ones. The treatment of cells with L-NAME decreased the level of SH-groups in cells and decreased fluorescence intensity of DNA-ethidium bromide complex during flow cytometry. Results obtained indicate the involvement of NO-dependent mechanism of the realization of the radiation-induced damage to the hereditary cell structure. Optimal conditions for the realization of the conceivable mechanism of radioprotective effect of L-NAME

  13. Structural changes in plasma membranes prepared from irradiated Chinese hamster V79 cells as revealed by Raman spectroscopy

    International Nuclear Information System (INIS)

    The effect of gamma irradiation on the integrity of plasma membranes isolated from Chinese hamster V79 cells was investigated by Raman spectroscopy. Plasma membranes of control V79 cells show transitions between -10 and 5 degree C (low-temperature transition), 10 and 22 degree C (middle-temperature transition), and 32 and 40 degree C (high-temperature transition). Irradiation (5 Gy) alters these transitions markedly. First, the low-temperature transition shifts to higher temperature (onset and completion temperatures 4 and 14 degree C). Second, the middle-temperature transition shifts up to the range of about 20-32 degree C, but the width remains unchanged. Third, the higher temperature transition broadens markedly and shifts to the range of about 15-40 degree C. Protein secondary structure as determined by least-squares analysis of the amide I bands shows 36% total helix, 55% total beta-strand, and 9% turn plus undefined for control plasma membrane proteins. Plasma membrane proteins of irradiated V79 cells show an increase in total helix (40 and 45% at 5 and 10 Gy, respectively) and a decrease in the total beta-strand (48 and 44% at 5 and 10 Gy, respectively) structures. The qualitative analysis of the Raman features of plasma membranes and model compounds in the 1600 cm-1 region, assigned to tyrosine groups, revealed that irradiation alters the microenvironment of these groups. We conclude that the radiation dose used in the survival range of Chinese hamster V79 cells can cause damage to plasma membrane proteins without detectable lipid peroxidation, and that the altered proteins react differently with lipids, yielding a shift in the thermal transition properties

  14. The ultra-fast repair of single-strand breaks in DNA of γ-irradiated Chinese hamster cells

    International Nuclear Information System (INIS)

    Studies of the effect of thermal treatment of Chinese hamster cells on sedimentation of DNA in the alkaline sucrose gradient showed that heating the cells to 680C for 15 min caused the same degradation as γ-irradiation with 5 to 7 krad at 370C. The inhibition of cellular repair enzymes by heating was therefore unacceptable. The process of ultra-fast repair is essentially determined by the DNA-ligase reaction, which is activated in the presence of Mg ions, and inhibited in mammalian cells in the presence of EDTA and pyrophosphate. Sedimentation profiles were therefore measured for the DNA of Chinese hamster cells γ-irradiated (5 krad) at 00C or 220C in the presence of Mg++, or EDTA and pyrophosphate, and the results demonstrated ultra-fast repair only at 20 to 370C, in contrast to bacteria. A study was made of the temperature dependence of the activity of the DNA ligases isolated from E.coli and rabbit bone marrow. The NAD-dependent bacterial DNA ligase was active at temperatures from 0 to 400C, whereas ATP-dependent DNA ligase of mammals only showed activity in the range 15 to 400C. The differing temperature dependences of ultra-fast repair in bacterial and mammalian cells are in agreement with the temperature dependences of the activities of isolated enzymes, and the results suggest that the process of ultra-fast repair of single-strand breaks of DNA takes place in both bacterial and mammalian cells. (U.K.)

  15. 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.

  16. The influence of non-uniform α-irradiation of Chinese hamster liver on chromosome damage and the induction of cancer

    International Nuclear Information System (INIS)

    In this study, Chinese hamsters received intravenous injections of Thorotrast (7.4, 1.5 or 0.30 Bq/g body weight) or monomeric 239Pu citrate (7.4 Bq/g), and were either sacrificed for cytogenetic analysis or held for lifespan dose-response observation. The frequency of chromosome aberrations observed in Thorotrast-exposed animals was 0.47 aberrations/cell Gy, similar to that in 239Pu citrate-injected hamsters. Using Cox proportional hazards analysis of the dose-response for several neoplastic and hyperplastic lesions observed in the liver, it was found that the relative risk for each endpoint was increased in a dose-related manner for all three dose levels of Thorotrast, and that risks for the plutonium-injected animals (7.4 Bq/g) were similar to those of hamsters injected with 1.5 Bq/g Thorotrast. (author)

  17. Cell growth stimulating effect of Ganoderma lucidum spores and their potential application for Chinese hamster ovary K1 cell cultivation.

    Science.gov (United States)

    Li, Ding; Zhong, Qi; Liu, Tingting; Wang, Jufang

    2016-06-01

    In this work, water-soluble extracts of Ganoderma lucidum spores (Gls), a Chinese medicinal herb that possesses cell growth stimulating function, were found to be an effective growth factor for Chinese hamster ovary (CHO) cell cultivation. The Gls extract was prepared and supplemented to CHO K1 cell culture media with various serum levels. Our results obtained from both the static culture and the spinner-flask suspension culture showed that use of small-amount Gls extract effectively promoted cell growth and suppressed cell apoptosis induced by serum deprivation with normal cell cycle maintained in a low-serum medium. The low-serum medium containing 1 % (v/v) fetal bovine serum (FBS) and 0.01 % (w/v) Gls extract showed a comparable performance on both cell growth and fusion protein productivity with the conventional CHO culture medium containing 10 % (v/v) FBS and a commercial serum-free medium. This is the first study of the potential of Gls extracts for use as an alternative cell growth factor and nutrient for CHO cells. The findings have presented a new approach to economic cultivation of CHO cells for therapeutic protein production. PMID:26921102

  18. Onderzoek naar de inductie van chromosoomafwijkingen en "sister- chromatid exchanges" door 2,3-epoxypropylmethacrylaat met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1986-01-01

    2,3-epoxypropylmethacrylaat of glycidylmethacrylaat bleek een clastogene werking te hebben in een test op chromosoomafwijkingen met Chinese hamster cellen in vitro, zowel in aan- als afwezigheid van een systeem voor metabolische activering (S9), bij concentraties vanaf 0,03 ul/ml (0,23 mmol/l). Tevens induceerde 2,3-epoxypropylmethacrylaat in deze cellen een significante toename in het aantal zuster-chromatide uitwisselingen (SCE's) per cel, zowel in afwezigheid van metabolische activeri...

  19. In vitro neuroprotective action of recombinant rat erythropoietin produced by astrocyte cell lines and comparative studies with erythropoietin produced by Chinese hamster ovary cells

    OpenAIRE

    Masuda, Seiji; Kada, Emi; Nagao, Masaya; Sasaki, Ryuzo

    1999-01-01

    In the central nervous system, astrocytes produce erythropoietin (Epo) and neurons express its receptor. To examine whether or not the brain Epo protects the in vitro cultured neurons from glutamate-induced cell death, we established rat astrocyte cell lines containing the plasmid for production of recombinant rat Epo. Epo partially purified from the culture medium showed a neuroprotective effect similar to that of rat Epo produced by Chinese hamster ovary (CHO) cells. Comparison was made in ...

  20. 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)

    A DNA preparation (molecular weight 19.6-21.0x1O6 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

  1. 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)

    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)

  2. 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)

    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

  3. Repair-deficient xeroderma pigmentosum cells made UV light resistant by fusion with X-ray-inactivated Chinese hamster cells

    International Nuclear Information System (INIS)

    Xeroderma pigmentosum (XP) is an autosomal recessive human disease, characterized by an extreme sensitivity to sunlight, caused by the inability of cells to repair UV light-induced damage to DNA. Cell fusion was used to transfer fragments of Chinese hamster ovary (CHO) chromosomes into XP cells. The hybrid cells exhibited UV resistance and DNA repair characteristics comparable to those expressed by CHO cells, and their DNA had greater homology with CHO DNA than did the DNA from XP cells. Control experiments consisted of fusion of irradiated and unirradiated XP cells and repeated exposure of unfused XP cells to UV doses used for hybrid selection. These treatments did not result in an increase in UV resistance, repair capability, or homology with CHO DNA. The hybrid cell lines do not, therefore, appear to be XP revertants. The establishment of these stable hybrid cell lines is an initial step toward identifying and cloning CHO DNA repair genes that complement the XP defect in human cells. The method should also be applicable to cloning genes for other diseases, such as ataxia-telangiectasia and Fanconi's anemia

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

    Science.gov (United States)

    Golabgir, Aydin; Gutierrez, Jahir M; Hefzi, Hooman; Li, Shangzhong; Palsson, Bernhard O; Herwig, Christoph; Lewis, Nathan E

    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 compilation covers all published CHO cell studies from 1995 to 2015, and each study is classified by the types of phenotypic and bioprocess data contained therein. Using data from selected studies, we also present a quantitative meta-analysis of bioprocess characteristics across diverse culture conditions, yielding novel insights and addressing the validity of long held assumptions. Specifically, we show that bioprocess titers can be predicted using indicator variables derived from viable cell density, viability, and culture duration. We further identified a positive correlation between the cumulative viable cell density (VCD) and final titer, irrespective of cell line, media, and other bioprocess parameters. In addition, growth rate was negatively correlated with performance attributes, such as VCD and titer. In summary, despite assumptions that technical diversity among studies and opaque publication practices can limit research re-use in this field, we show that the statistical analysis of diverse legacy bioprocess data can provide insight into bioprocessing capabilities of CHO cell lines used in industry. The CHO bibliome can be accessed at http://lewislab.ucsd.edu/cho-bibliome/. PMID:26948029

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 [32P]phosphatidylcholine, phosphatidylserine in the parent accumulated radioactivity while that in the mutant was not labeled significantly. On the contrary, when cultured with [32P]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

  7. Increased recombinant protein production owing to expanded opportunities for vector integration in high chromosome number Chinese hamster ovary cells.

    Science.gov (United States)

    Yamano, Noriko; Takahashi, Mai; Ali Haghparast, Seyed Mohammad; Onitsuka, Masayoshi; Kumamoto, Toshitaka; Frank, Jana; Omasa, Takeshi

    2016-08-01

    Chromosomal instability is a characteristic of Chinese hamster ovary (CHO) cells. Cultures of these cells gradually develop heterogeneity even if established from a single cell clone. We isolated cells containing different numbers of chromosomes from a CHO-DG44-based human granulocyte-macrophage colony stimulating factor (hGM-CSF)-producing cell line and found that high chromosome number cells showed higher hGM-CSF productivity. Therefore, we focused on the relationship between chromosome aneuploidy of CHO cells and high recombinant protein-producing cell lines. Distribution and stability of chromosomes were examined in CHO-DG44 cells, and two cell lines expressing different numbers of chromosomes were isolated from the original CHO-DG44 cell line to investigate the effect of aneuploid cells on recombinant protein production. Both cell lines were stably transfected with a vector that expresses immunoglobulin G3 (IgG3), and specific antibody production rates were compared. Cells containing more than 30 chromosomes had higher specific antibody production rates than those with normal chromosome number. Single cell analysis of enhanced green fluorescent protein (Egfp)-gene transfected cells revealed that increased GFP expression was relative to the number of gene integration sites rather than the difference in chromosome numbers or vector locations. Our results suggest that CHO cells with high numbers of chromosomes contain more sites for vector integration, a characteristic that could be advantageous in biopharmaceutical production. PMID:26850366

  8. Enhancement of chromosome aberrations induced in 5'-bromodeoxyuridine-labelled Chinese hamster ovary cells by monochromatic synchrotron radiations

    International Nuclear Information System (INIS)

    The chromosome study for the radiation-induced enhancement in producing various types of aberrations was conducted in a cultured cell line of CHO (Chinese hamster ovary) cells that were pre-labeled with BUdR (5'-deoxybromouridine) and irradiated by monochromatic X-rays with a slightly shorter wavelength (0.9 A) than the K adsorption edge of bromine (0.92 A). The dose-response changes in terms of frequencies of single-arm breaks and isochromatid breaks have shown that a maximum effect was produced by the combination of 0.9-A wavelength of X-irradiation and Br-incorporation and was above the magnitude of the so-called brome-induced sensitization obtained with 1.0-A wavelength X-rays. Such additional effect in the bromine-sensitized cells may be interpreted as the biological effect due to Auger electrons produced by photoelectric stimulation with 0.9-A monochromatic X-rays

  9. Dose dependence of the oxygen enhancement ratio (OER) in radiation inactivation of Chinese hamster V79-171 cells

    International Nuclear Information System (INIS)

    The dose dependence of the oxygen enhancement ratio (OER) has been examined through multiple measurements of the response of Chinese hamster V79-171 cells to low and high doses of radiation under aerobic and hypoxic conditions. In this series of experiments the cells were maintained at 37 degrees C throughout the gassing and irradiation periods, to simulate normal physiological conditions. Flow cytometry and cell sorting techniques were used to facilitate accurate measurement of cell survival throughout the dose range, but particularly at low dose. The OER was found to decrease significantly at low dose, qualitatively confirming earlier reports from this laboratory, though the decrease was somewhat smaller in the present series. This difference may be a temperature effect since in the earlier experiments irradiation was at 0 degree C. This report shows that the OER decreases from a value of 2.87 ± 0.16 (standard deviation of mean) at S = 0.01 to 2.36 ± 0.19 at S = 0.80. Both alpha and beta are altered by the presence of oxygen. The OER is presented as a function of dose in nitrogen

  10. Heterologous transmembrane signaling by a human insulin receptor-v-ros hybrid in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    A hybrid receptor molecule composed of the extracellular ligand-binding domain of the human insulin receptor and the transmembrane and cytoplasmic (protein-tyrosine kinase) domains of the chicken sarcoma virus UR2 transforming protein p68/sup gag-ros/ has been constructed and expressed in Chinese hamster ovary (CHO) cells. The hybrid is processed normally into α and hybrid β subunits, is expressed on the cell surface at high levels, and binds insulin with near-wild-type affinity. Furthermore, insulin stimulates the phosphorylation on tyrosine resides of the hybrid β-subunit in vivo and the phosphorylation of an exogeneous substrate [poly(Glu,Tyr)] in vitro. Thus the hybrid is capable of heterologous transmembrane signaling. However, the hybrid mediates neither the insulin-activated uptake of 2-deoxyglucose nor the incorporation of [3H]thymidine into DNA, suggesting that the physiological response(s) mediated by ligand-activated protein-tyrosine kinases may utilize distinct intracellular mechanisms for postreceptor signaling

  11. Heterologous transmembrane signaling by a human insulin receptor-v-ros hybrid in Chinese hamster ovary cells

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.; Morgan, D.O.; Jong, S.M.; Wang, L.H.; Roth, R.A.; Rutter, W.J.

    1987-08-01

    A hybrid receptor molecule composed of the extracellular ligand-binding domain of the human insulin receptor and the transmembrane and cytoplasmic (protein-tyrosine kinase) domains of the chicken sarcoma virus UR2 transforming protein p68/sup gag-ros/ has been constructed and expressed in Chinese hamster ovary (CHO) cells. The hybrid is processed normally into ..cap alpha.. and hybrid ..beta.. subunits, is expressed on the cell surface at high levels, and binds insulin with near-wild-type affinity. Furthermore, insulin stimulates the phosphorylation on tyrosine resides of the hybrid ..beta..-subunit in vivo and the phosphorylation of an exogeneous substrate (poly(Glu,Tyr)) in vitro. Thus the hybrid is capable of heterologous transmembrane signaling. However, the hybrid mediates neither the insulin-activated uptake of 2-deoxyglucose nor the incorporation of (/sup 3/H)thymidine into DNA, suggesting that the physiological response(s) mediated by ligand-activated protein-tyrosine kinases may utilize distinct intracellular mechanisms for postreceptor signaling

  12. Characteristic element of matrix attachment region mediates vector attachment and enhances nerve growth factor expression in Chinese hamster ovary cells.

    Science.gov (United States)

    Wang, X Y; Zhang, J H; Sun, Q L; Yao, Z Y; Deng, B G; Guo, W Y; Wang, L; Dong, W H; Wang, F; Zhao, C P; Wang, T Y

    2015-01-01

    Preliminary studies have suggested that a characteristic element of the matrix attachment region (MAR) in human interferon-β mediates the adhesion of vectors to Chinese hamster ovary (CHO) cells. In this study, we investigated if vector adhesion increased nerve growth factor (NGF) expression in CHO cells. The MAR characteristic element sequence of human interferon-β was inserted into the multiple-cloning site of the pEGFP-C1 vector. The target NGF gene was inserted upstream of the MAR characteristic element sequence to construct the MAR/NGF expression vector. The recombinant plasmid was transfected into CHO cells and stable monoclonal cells were selected using G418. NGF mRNA and protein expression was detected by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Plasmid reduction experiments were used to determine the state of transfected plasmid in mammalian cells. The insertion of MAR into the vector increased NGF expression levels in CHO cells (1.93- fold) compared to the control. The recombinant plasmid expressing the MAR sequence was digested into a linear space vector. The inserted MAR and NGF sequences were consistent with those inserted into the plasmid before recombination. Therefore, we concluded that the MAR characteristic element mediates vector adhesion to CHO cells and enhances the stability and efficiency of the target gene expression. PMID:26345852

  13. Sensitization by wortmannin of heat- or X-ray induced cell death in cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Here we found that wortmannin sensitized Chinese hamster V79 cells to hyperthermic treatment at 44.0 deg C as determined either by colony formation assay or by dye exclusion assay. Wortmannin enhanced heat-induced cell death accompanying cleavage of poly (ADP-ribose) polymerases (PARP). Additionally, the induction of heat shock protein HSP70 was suppressed and delayed in wortmannin-treated cells. Heat sensitizing effect of wortmannin was obvious at more than 5 or 10 μM of final concentrations, while radiosensitization was apparent at 5 μM. Requirement for high concentration of wortmannin, i.e., order of μM, suggests a possible role of certain protein kinases, such as DNA-PK and/or ATM among PI3-kinase family. The sensitization was minimal when wortmannin was added at the end of heat treatment. This was similar to the case of X-ray. Since heat-induced cell death and PARP cleavage preceded HSP70 induction phenomenon, the sensitization to the hyperthermic treatment was considered mainly caused by enhanced apoptotic cell death rather than secondary to suppression or delay by wortmannin of HSP70 induction. Further, in the present system radiosensitization by wortmannin was also at least partly mediated through enhancement of apoptotic cell death. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Angshuman; Shah, Sunil [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat-390002 (India); Kulkarni, Vijay; Murthy, R.S.R. [G. H. Patel Pharmacy Building, TIFAC-CORE in NDDS, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat-390002 (India); Devi, Surekha [Department of Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat-390002 (India)], E-mail: surekha_devi@yahoo.com

    2009-01-15

    Gold-silver alloy nanoparticles were synthesized by simultaneous reduction of varying mole fractions of HAuCl{sub 4} and AgNO{sub 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.

  15. Interaction function gamma(x) for Chinese hamster cells treated with hypertonic phosphate-buffered saline after irradiation

    International Nuclear Information System (INIS)

    The repair of potentially lethal damage (PLD) in stationary-phase V79 Chinese hamster cells, which was expressible by a postirradiation treatment with hypertonic (0.5 M NaCl) phosphate-buffered saline (PBS), was analyzed within the framework of the theory of dual radiation action. The interaction function gamma(x) was estimated for cells permitted to repair PLD for various intervals of time. The experimental data indicated that 50-60% of the lethal lesions produced at the time of irradiation were repaired in 120 min. The repair of PLD was implicitly involved in the probability of the interaction of sublesions. That is, g(x,trep) was defined as the probability that two sublesions separated by distance x interact to produce a lethal lesion which will not be repaired until the fixation by treatment with hypertonic PBS at time trep after irradiation. It is concluded that the time dependence of the repair of PLD is not independent of the interaction distance x. Three conclusions are drawn: (1) The repair of a lesion produced by a long distance interaction is not detectable by postirradiation treatment with hypertonic PBS. (2) A lesion produced by a short distance interaction is rapidly repaired in about 20 min. (3) A lesion produced by the interaction of sublesions separated by a distance of about 100 nm is repaired slowly

  16. DNA replication in ultraviolet light irradiated Chinese hamster cells: the nature of replicon inhibition and post-replication repair

    International Nuclear Information System (INIS)

    DNA replication in ultraviolet light irradiated Chinese hamster cells was studied using techniques of DNA fiber autoradiography and alkaline sucrose sedimentation. Bidirectionally growing replicons were observed in the autoradiograms independent of the irradiation conditions. After a dose of 5 J/m2 at 254 nm the rate of fork progression was the same as in unirradiated cells, while the rate of replication was reduced by 50%. After a dose of 10J/m2 the rate of fork progression was reduced 40%, while the replication rate was only 25% of normal. Therefore, at low doses of ultraviolet light irradiation, the inhibition of DNA replication is due to reduction in the number of functioning replicons, while at higher doses the rate of fork progression is also slowed. Those replicons which no longer function after irradiation are blocked in fork movement rather than replicon initiation. After irradiation, pulse label was first incorporated into short nascent strands, the average size of which was approximately equal to the distance between pyrimidine dimers. Under conditions where post-replication repair occurs these short strands were eventually joined into larger pieces. Finally, the data show that slowing post-replication repair with caffeine does not slow fork movement. The results presented here support the post-replication repair model of 'gapped synthesis' and rule out a major role for 'replicative bypass'. (author)

  17. Cell-cycle specific expression of a small proline-rich protein in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Squamous metaplasia of the bronchial epithelium is generally believed to be involved in the neoplastic progression toward squamous cell carcinomas. Thus, it is important to understand the mechanisms controlling this type of differentiation. The induction of two families of cDNAs encoding a small proline-rich protein (sPRP), sprI and sprII, was first identified in human keratinocytes exhibiting squamous differentiation. cDNAs similar to sprI have also been identified in cultured tracheal epithelial cells undergoing squamous differentiation. The first step during the squamous differentiation process is the inhibition of cell growth; it has also been noted that a sPRP mRNA in Chinese hamster ovary (CHO) cells is induced 10-fold just before the cultures reach confluence. Thus, sPRP may stop cell division in cells undergoing squamous differentation. In support of this possibility are the recent investigations correlating expression of sPRP with cell morphology. Specific immunoreactivity to sPRP, using affinity-purified antibodies, showed a strong immunostaining in cells with a round configuration, while less staining was observed in other cells. The major part of the CHO population showed no immunoreactivity. One interpretation of this observation is that the expression of sPRP may be cell-cyle regulated. The purpose of this investigation was to determine the phase of the cell cycle where induced synthesis of sPRP mRNA occurs

  18. Inhibition of DNA excision repair by methotrexate in Chinese hamster ovary cells following exposure to ultraviolet irradiation or ethylmethanesulfonate

    International Nuclear Information System (INIS)

    Previous results have suggested that methotrexate (MTX) could interfere with the repair of spontaneous DNA damage. To determine its effects on induced DNA damage, MTX was compared to hydroxyurea and arabinofuranosylcytosine (H/A), a drug combination known to block the DNA polymerase step of excision repair, for its ability to cause the accumulation of single-strand breaks (SSB) following exposure to either UV light or the alkylating agent ethylmethanesulfonate in Chinese hamster ovary cells. SSB were measured by alkaline elution 1, 2, and 6 h after exposure to either 1.8 mg/ml of ethylmethanesulfonate or 10 J/m2 of UV in cells pretreated with MTX or H/A. Following exposure to ethylmethanesulfonate, significant accumulation of SSB occurred in cells pretreated with either H/A or MTX. Coadministration of hypoxanthine and thymidine in MTX-treated cells prevented SSB accumulation, indicating that nucleotide depletion by MTX had inhibited repair synthesis. After UV irradiation, SSB accumulation was much less in MTX- than in H/A-treated cells. MTX was found to have no effect on the incision of UV damage. These results indicate that nucleotide depletion by MTX can affect the repair of DNA damage by exogenous agents, and that the extent of inhibition is dependent on the type of damage induced

  19. 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.

  20. Expression of secreted recombinant human insulin-like growth factor-II (IGF-II) in Chinese hamster ovary cells.

    Science.gov (United States)

    Bekkari, H; Sekkat, D; Straczek, J; Hess, K; Belleville-Nabet, F; Nabet, P

    1994-07-29

    Chinese hamster ovary (CHO-KI) cells were cotransfected with a plasmid pcDNAI containing the human preproinsulin-like growth factor II cDNA linked downstream to the human cytomegalovirus promoter and with a plasmid containing the neomycin resistance gene (pMAM-neo). CHO neo+ were selected by growth in medium supplemented with G418 geneticin. After amplification, the neomycin-resistant clones were screened for IGF-II production. IGF-II produced was identified by dot blot and quantified by ELISA. The clones C24, C40 and C94 secreted IGF-II at about 350-400 ng per 10(6) cells per day. DNA analysis of C24 and C40 CHO cells by PCR demonstrated the presence of the IGF-II construct in the transfected cells, presumably integrated into the chromosomal DNA. IGF-II produced by CHO cells and purified by RP-HPLC was a mitogen for MCF-7 stimulating mitosis 2-fold. PMID:7765161

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

    International Nuclear Information System (INIS)

    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-G1 cells were heated by submerging culture flasks in a 44 +- 0.050C 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 440C 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 440C 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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  4. Elastatinal and leupeptin: effects on u.v.-induced mutation and sister-chromatid exchanges in Chinese hamster cells

    International Nuclear Information System (INIS)

    Microbial protease inhibitors elastatinal and leupeptin were tested for cytotoxicity and for effects on spontaneous and u.v.-induced 6-thioguanine-resistant (6TGr) mutation and sister-chromatid exchange (SCE) in V79 Chinese hamster cells. Continuous treatment with elastatinal exhibited marked cytotoxicity, while leupeptin was almost non-cytotoxic. Elastatinal rapidly induced cytotoxic effects as a function of its concentration and time of exposure. Near maximum cytotoxicity was reached after exposure of 6-8 h and this was partially abolished by the presence of 2.5 micrograms cycloheximide per ml. Concentrations of either protease inhibitor which gave 60-80% survival had no appreciable effects on u.v. survival and frequencies of spontaneous and u.v.-induced 6TGr mutation and SCE. However, reconstruction experiments revealed that pretreatments of 6TGr and 6TGs (wild-type) cells with these inhibitors for 6 days tended to block metabolic co-operation in their co-cultures. Thus, elastatinal and leupeptin are neither clastogenic mutagenic by themselves, and do not alter mutation fixation and expression

  5. Induction during G1 of heat radiosensitization in Chinese hamster ovary cells following single and fractionated heat doses

    International Nuclear Information System (INIS)

    When G1 Chinese hamster ovary cells were heated at 42.2 degrees C and X-irradiated, heat radiosensitization increased slightly with cell killing. However, when thermo-tolerance was allowed to develop by continuous heating for periods longer than 4 hours, which reduces survival to 0.18, heat radiosensitization no longer increased with continued heating or cell killing. When cells were heated with single doses at 45.5 degrees C, heat radiosensitization increased as a function of heat killing. However, if acute heat doses at 45.5 degrees C were fractionated and cells incubated for 10 hours at 37 degrees C between fractions, significant tolerance to heat radiosensitization was observed. For example, heating cells at 45.5 degrees C for 15 minutes reduced survival to 0.40 and decreased the D0 to 0.45 gray, whereas 2 fractionated 15-minute doses at 45.5 degrees C, separated by 10 hours at 37 degrees C, resulted in a D0 of 0.65 gray. Thus if heat killing increased without the development of thermotolerance, heat radiosensitization also increased continually, whereas when thermotolerance developed after continuous or fractionated heating without cell progression, some tolerance to continued heat radiosensitization also was observed. This tolerance to both heat killing and heat radiosensitization indicates that both involve similar target(s)

  6. Response of Chinese hamster ovary cells to fast neutron radiotherapy beams. I. Relative biological effectiveness and oxygen enhancement ratio

    International Nuclear Information System (INIS)

    The relative biological effectiveness (RBE) and oxygen enhancement ratio (OER) were determined for fast neutron beams produced by both 16-MeV and 50-MeV 2H on Be at the Texas A and M Variable Energy Cyclotron (TAMVEC). These beams have average neutron energies of 7 and 21 MeV, respectively. The biological system used in these experiments was Chinese hamster ovary cells in tissue culture. The results indicated that although the RBE of the 21-MeV beam was about 15 percent lower than that for the 7-MeV beam at 0.1 percent survival there was no change in RBE for either beam with depth in a tissue-equivalent phantom. The OER of the 7-MeV beam was found to be 1.5 +- 0.3 and the 21-MeV beam had an OER of 1.2 +- 0.2, which resulted in gain factors of 1.7 and 2.1, respectively, when compared to 60Co gamma rays (OER = 2.5). No variation in OER with depth was detected. It was concluded that the 21-MeV TAMVEC beam should be as applicable to radiotherapy from the radiobiological point of view as a 7-MeV beam

  7. 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

  8. Effects of 2'-chlorothymidine on Chinese hamster cells irradiated with x-rays and ultraviolet light

    International Nuclear Information System (INIS)

    Effects of 2'-chlorothymidine (2'-Cl-TdR) and its mother compound, thymidine (TdR), on cell killing induced by X- and UV-irradiation have been investigated. Chinse hamster V-79 (TK+) cells as well as thymidine kinase deficient (TK-) variant cells, which were isolated from parental V-79 cells following stepwise treatment with BUdR, were incubated in a medium containing 2'-Cl-TdR and TdR after X- and UV-irradiation. In the TK+ cells, both 2'-Cl-TdR and TdR enhanced the killing efficiency of X-rays and ultraviolet light. On the other hand, in the TK- cells, only 2'-Cl-TdR enhanced the killing efficiency of X- and UV-irradiation, and no effect of TdR was observed. These results suggest that phosphorylation of TdR by the enzyme is essential for its ability to modify radiation response, while the enhancement of cell killing by 2'-Cl-TdR must be explained by a mechanism at least partly independent of phosphorylation. (author)

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

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    Maria Cristina P. Araújo

    1999-09-01

    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.Antioxidantes de ocorrência natural têm sido exaustivamente estudados quanto a sua capacidade de proteger organimos e células contra danos oxidativos. Muitos constituintes das plantas, incluindo cúrcuma e curcumina, parecem ser potentes antimutágenos e antioxidantes. Os efeitos de cúrcuma e curcumina na freqüência de aberrações cromossômicas induzidas pelo agente radiomimético bleomicina (BLM foram investigados em células do ovário de hamster chinês (CHO. Três concentrações de cada droga, cúrcuma (100, 250 e 500 mg/ml e curcumina (2,5, 5,0 e 10 mg/ml, foram combinadas com BLM (10 mg/ml em células CHO tratadas durante as fases G1/S, S ou G2/S do ciclo celular. Nem cúrcuma nem curcumina evitaram o dano cromossômico induzido pela BLM em fase alguma do ciclo celular. Ao contrário, a potenciação da clastogenicidade da BLM pelo curcumina foi nitidamente observada em células tratadas

  10. The role of non-protein sulphydryls in determining the chemical repair rates of free radical precursors of DNA damage and cell killing in Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Chinese hamster V79 fibroblasts were irradiated in the gas explosion apparatus and the chemical repair rates of the oxygen-dependent free radical precursors of DNA double-strand breaks (dsb) and lethal lesions measured using filter elution (pH 9.6) and a clonogenic assay. Depletion of cellular GSH levels, from 4.16 fmol/cell to 0.05 fmol/cell, by treatment with buthionine sulphoximine (50 μmol dm-3; 18 h), led to sensitization as regards DNA dsb induction and cell killing. This was evident at all time settings but was particularly pronounced when the oxygen shot was given 1 ms after the irradiation pulse. A detailed analysis of the chemical repair kinetics showed that depletion of GSH led to a reduction in the first-order rate constant for dsb precursors from 385 s-1 to 144 s-1, and for lethal lesion precursors from 533 s-1 to 165 s-1. (Author)

  11. The effects of differential polyadenylation on expression of the dihydrofolate reductase-encoding gene in Chinese hamster lung cells.

    Science.gov (United States)

    Yang, H; Hussain, A; Melera, P W

    1995-10-01

    Three differently sized mRNAs are expressed from each of two DHFR (encoding dihydrofolate reductase) alleles present in the Chinese hamster lung (CHL) cell line, DC-3F. The relative abundancy of the transcripts produced from each allele differs dramatically as a result of differential utilization of the multiple poly(A) sites present in the DHFR DHFR gene and a genetic polymorphism located within the third poly(A) signal of one allele. We sought to determine whether such differences in polyadenylation affect the steady-state levels of DHFR and mRNAs expressed from either allele and, in a more general sense, to ask whether differences in 3' end RNA processing in a gene containing multiple poly(A) sites affects the final level of gene expression. An SV40 promoter-based transient expression system producing chimeric cat::DHFR transcripts was developed to regenerate the in vivo mRNA polyadenylation patterns associated with each of the two DHFR alleles. The results demonstrate that the total amount of polyadenylated RNA expressed from each of these constructs in vitro is the same regardless of the differential utilization of the poly(A) signals that occurs between them. Moreover, measurement of the individual turnover rates of the DHFR mRNAs expressed in vivo from each allele, as determined by pulse-chase labeling and actinomycin D inhibition studies, revealed no significant allele-specific differences in transcript half-lives. Finally, measuring the steady-state levels of DHFR poly(A)+ mRNA in parental DC-3F cells demonstrated that both alleles are expressed to the same extent during normal growth. Thus, even though dramatic allele-specific differences in 3' end processing of DHFR transcripts occur in vivo, such differences do not appear to influence the steady-state levels of DHFR gene expression. PMID:7590264

  12. Regulation of cell growth and apoptosis through lactate dehydrogenase C over-expression in Chinese hamster ovary cells.

    Science.gov (United States)

    Fu, Tuo; Zhang, Cunchao; Jing, Yu; Jiang, Cheng; Li, Zhenhua; Wang, Shengyu; Ma, Kai; Zhang, Dapeng; Hou, Sheng; Dai, Jianxin; Kou, Geng; Wang, Hao

    2016-06-01

    Lactate has long been credited as a by-product, which jeopardizes cell growth and productivity when accumulated over a certain concentration during the manufacturing process of therapeutic recombinant proteins by Chinese hamster ovary (CHO) cells. A number of efforts to decrease the lactate concentration have been developed; however, the accumulation of lactate is still a critical issue by the late stage of fed-batch culture. Therefore, a lactate-tolerant cell line was developed through over-expression of lactate dehydrogenase C (LDH-C). In fed-batch culture, sodium lactate or sodium pyruvate was supplemented into the culture medium to simulate the environment of lactate accumulation, and LDH-C over-expression increased the highest viable cell density by over 30 and 50 %, respectively, on day 5, meanwhile the viability was also improved significantly since day 5 compared with that of the control. The percentages of cells suffering early and late apoptosis decreased by 3.2 to 12.5 and 2.0 to 4.3 %, respectively, from day 6 onwards in the fed-batch culture when 40 mM sodium pyruvate was added compared to the control. The results were confirmed by mitochondrial membrane potential assay. In addition, the expression of cleaved caspases 3 and 7 decreased in cells over-expressing LDH-C, suggesting the mitochondrial pathway was involved in the LDH-C regulated anti-apoptosis. In conclusion, a novel cell line with higher lactate tolerance, lowered lactate production, and alleviated apoptosis response was developed by over-expression of LDH-C, which may potentially represent an efficient and labor-saving approach in generating recombinant proteins. PMID:26841889

  13. The insulin receptor as a transmitter of a mitogenic signal in Chinese hamster ovary CHO-K1 cells

    International Nuclear Information System (INIS)

    Insulin is the only hormone required for continued growth of Chinese hamster ovary CHO-K1 cells in the defined medium M-F12. When CHO-K1 cells are incubated in M-F12 without insulin for 48-72 hr, the cells accumulate in G1. In response to physiological concentrations of insulin an 18-fold increase in rate of DNA synthesis occurs due to cells entering S phase after an 8- to 10-hr lag; cell division begins after 24 hr. The inhibitory effect of actinomycin D and 5,6-dichlorobenzimidazole riboside indicates that RNA synthesis is required for progression to S phase. CHO-K1 cells possess insulin receptors, and the insulin effect results from insulin binding to its own receptor: (i) binding occurs at physiological insulin concentrations with a half-maximal stimulation at ∼ 14 ng/ml. (ii) At insulin concentrations used, insulin-like growth factor I and II (IGF-I and IGF-II) have little or no effect. (iii) Scatchard analysis of 125I-labeled insulin binding shows the curvilinear response typical of insulin. (iv) The Kd for the so-called high-affinity binding site and the Ke are characteristic of the insulin receptor. (v) At the minimal insulin concentrations that stimulate growth, IGF-I and IGF-II compete poorly with insulin for insulin binding, insulin competes poorly with IGF-I for IGF-I binding, and affinity labeling with 125I-labeled insulin identifies as polypeptide typical of the α subunit of the insulin receptor

  14. Modulation of radiation-induced mutation frequencies and DNA synthesis by deoxycytidine in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The goal of this project is to elucidate and model the impact of perturbations in cellular metabolism on the cellular response to DNA damage. Previously reported experiments established roles for DNA synthesis and the inhibition of DNA synthesis in the expression of radiation-induced mutations. This year, these experiments were continued and the study was expanded. Two different Chinese hamster ovary (CHO) cell lines were examined. Experimental measurements were obtained for cells in one of two growth media: (1) medium A, which consisted of Ham's F-12 containing 10% fetal calf serum; or (2) medium B, which consisted of medium A containing 2 mm deoxycytidine (CdR). The presence of CdR differentially affected the nature of DNA replication, the inhibition of replication by radiation, and the corresponding mutation frequency responses. Results suggest that the effect of CdR on mutation-induction is not locus-specific. Moreover, the phenomenal reduction in the mutation response in the presence of CdR is also seen following exposure to ionizing radiation, which implies that the effect of CdR is not mutagen-specific. Time-dependent changes in profiles of pulse-labeled DNA on alkaline sucrose gradients were employed to measure and compare nascent DNA chain growth processes in the two media. Results suggest that a more rapid DNA chain elongation and/or replicon mutation rate occurs in cells in medium B. In contrast, the sedimentation of one pulse-labeled CHO cell line DNA is always greater when cells are grown in medium A. UV radiation appears to inhibit postirradiation replicon initiation events and results in reduced mutation frequencies when cells are grown in the medium that promotes the more rapid rate of polymerization

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

    Science.gov (United States)

    Peterson, A R; Peterson, H

    1982-03-01

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

  16. 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)

  17. Activation of two new alpha(1,3)fucosyltransferase activities in Chinese hamster ovary cells by 5-azacytidine.

    Science.gov (United States)

    Potvin, B; Stanley, P

    1991-01-01

    Several mammalian alpha(1,3)fucosyltransferases (alpha[1,3]Fuc-T) that synthesize carbohydrates containing alpha(1,3)fucosylated lactosamine units have been identified. Although Chinese hamster ovary (CHO) cells do not express alpha(1,3)Fuc-T activity, the rare mutants LEC11 and LEC12, isolated after mutagenesis or DNA transfection, each express an alpha(1,3)Fuc-T that may be distinguished by several criteria. Two new CHO mutants possessing alpha(1,3)Fuc-T activity (LEC29 and LEC30) have now been isolated after treatment of a CHO cell population with 5-azacytidine (5-AzaC), ethylnitrosourea (ENU), or 5-AzaC followed by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Like LEC12, both mutants possess an N-ethylmaleimide-resistant alpha(1,3)Fuc-T activity that can utilize a variety of acceptors and both express the Lewis X (Lex) determinant (Gal beta[1,4](Fuc alpha[1,3])GlcNAc beta 1)) but not the sialyl alpha(2,3)Lex determinant on cell-surface carbohydrates. However, LEC29 and LEC30 may be distinguished from LEC11 and LEC12, as well as from each other, on the basis of their unique patterns of lectin resistance and their abilities to bind the VIM-2 monoclonal antibody that recognizes carbohydrates terminating in NeuNAc alpha(2,3)Gal beta(1,4)GlcNAc beta(1,3)Gal beta(1,4)(Fuc alpha[1,3])GlcNAc beta and also by the different in vitro substrate specificities and kinetic properties of their respective alpha(1,3)Fuc-T activities. The combined data provide good evidence that the LEC29 and LEC30 alpha(1,3)Fuc-Ts are novel transferases encoded by distinct gene products. PMID:1724918

  18. Differential gene expression in wild-type and X-ray-sensitive mutants of Chinese hamster ovary cell lines

    International Nuclear Information System (INIS)

    Complementary DNA cloning, differential screening and Northern hybridization techniques were used to study differential gene expression in wild-type Chinese hamster ovary (CHO) K1 cell line and its two X-ray sensitive mutants, xrs-5 and xrs-6. Eleven species of mRNAs were found under-expressed in two independently isolated mutants. The steady-state levels of those mRNAs are 3-26-fold less in the 2 mutants, depending on the particular species. Of underexpressed mRNAs, 6 have been identified by comparing sequences of cloned cDNAs to the known sequences in GenBank 4 of them code for the structural proteins of ferritin heavy chain, non- muscle myosin light chain 3nm, ribosomal protein S17 and L7, resp. The other 2 have strong homology with mouse B2 or retroviral sequences. The remaining 5 mRNAs did not show significant homology with any of the known sequences and apparently represent newly isolated species. Effects of 137Cs γ-rays on the expression of the 11 mRNAs has been studied. Radiation inhibited expression of the B2-like gene in mutants but not in the wild type CHO cells. Levels of the other 10 mRNAs were not affected by radiation. The underexpression of this group of genes in both xrs-5 and xrs-6 mutants seems to be related to their radiation- sensitive phenotype, although the specific gene responsible has not been identified. Two models are proposed to explain the mechanism of under- expression. It is suggested that a cellular factor or/and chromosome structural changes are involved. (author). 33 refs.; 4 figs.; 1 tab

  19. Effect of taxol on chromosome aberrations induced by gamma radiation or by doxorubicin in Chinese hamster ovary cells

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    Francisca da Luz Dias

    1997-09-01

    Full Text Available Combined therapy with radiation and chemotherapy has being increasingly used in cancer treatment. The effect of combinations of taxol (0.08 mug/ml with doxorubicin (DXR, 0.5 or 1.0 mug/ml or gamma radiation (20 or 40 cGy was examined in two different treatment schedules (pretreatment or simultaneous treatment using Chinese hamster ovary (CHO cells treated at the G2 phase of the cell cycle. The results showed that taxol did not have a radiosensitizing effect on the chromosomal aberrations induced by gamma radiation nor did it have a potentiating effect on the chromosomal aberrations induced by DXR in CHO cells treated in the G2 phase of the cell cycleA terapia combinada com radiação e agentes químicos tem aumentado nos regimes de tratamento do câncer. Nesse estudo foi investigado o efeito das combinações de taxol (0,08 mig/ml com a doxorubicina (DXR 0,5 ou 1,0 mig/ml ou com as radiações gama (20 ou 40 cGy em dois diferentes protocolos de tratamento (pré-tratamento e simultâneo em células CHO tratadas na fase G2 do ciclo celular. Os resultados mostraram que o taxol não teve efeito sensibilizador sobre as aberrações cromossômicas induzidas pelas radiações gama, nem teve efeito potenciador sobre as aberrações cromossômicas induzidas pela DXR em células CHO tratadas na fase G2 do ciclo celular

  20. Thresholds for phosphatidylserine externalization in Chinese hamster ovarian cells following exposure to nanosecond pulsed electrical fields (nsPEF).

    Science.gov (United States)

    Vincelette, Rebecca L; Roth, Caleb C; McConnell, Maureen P; Payne, Jason A; Beier, Hope T; Ibey, Bennett L

    2013-01-01

    High-amplitude, MV/m, nanosecond pulsed electric fields (nsPEF) have been hypothesized to cause nanoporation of the plasma membrane. Phosphatidylserine (PS) externalization has been observed on the outer leaflet of the membrane shortly after nsPEF exposure, suggesting local structural changes in the membrane. In this study, we utilized fluorescently-tagged Annexin V to observe the externalization of PS on the plasma membrane of isolated Chinese Hamster Ovary (CHO) cells following exposure to nsPEF. A series of experiments were performed to determine the dosimetric trends of PS expression caused by nsPEF as a function of pulse duration, τ, delivered field strength, ED, and pulse number, n. To accurately estimate dose thresholds for cellular response, data were reduced to a set of binary responses and ED50s were estimated using Probit analysis. Probit analysis results revealed that PS externalization followed the non-linear trend of (τ*ED (2))(-1) for high amplitudes, but failed to predict low amplitude responses. A second set of experiments was performed to determine the nsPEF parameters necessary to cause observable calcium uptake, using cells preloaded with calcium green (CaGr), and membrane permeability, using FM1-43 dye. Calcium influx and FM1-43 uptake were found to always be observed at lower nsPEF exposure parameters compared to PS externalization. These findings suggest that multiple, higher amplitude and longer pulse exposures may generate pores of larger diameter enabling lateral diffusion of PS; whereas, smaller pores induced by fewer, lower amplitude and short pulse width exposures may only allow extracellular calcium and FM1-43 uptake. PMID:23658665

  1. Thresholds for phosphatidylserine externalization in Chinese hamster ovarian cells following exposure to nanosecond pulsed electrical fields (nsPEF.

    Directory of Open Access Journals (Sweden)

    Rebecca L Vincelette

    Full Text Available High-amplitude, MV/m, nanosecond pulsed electric fields (nsPEF have been hypothesized to cause nanoporation of the plasma membrane. Phosphatidylserine (PS externalization has been observed on the outer leaflet of the membrane shortly after nsPEF exposure, suggesting local structural changes in the membrane. In this study, we utilized fluorescently-tagged Annexin V to observe the externalization of PS on the plasma membrane of isolated Chinese Hamster Ovary (CHO cells following exposure to nsPEF. A series of experiments were performed to determine the dosimetric trends of PS expression caused by nsPEF as a function of pulse duration, τ, delivered field strength, ED, and pulse number, n. To accurately estimate dose thresholds for cellular response, data were reduced to a set of binary responses and ED50s were estimated using Probit analysis. Probit analysis results revealed that PS externalization followed the non-linear trend of (τ*ED (2(-1 for high amplitudes, but failed to predict low amplitude responses. A second set of experiments was performed to determine the nsPEF parameters necessary to cause observable calcium uptake, using cells preloaded with calcium green (CaGr, and membrane permeability, using FM1-43 dye. Calcium influx and FM1-43 uptake were found to always be observed at lower nsPEF exposure parameters compared to PS externalization. These findings suggest that multiple, higher amplitude and longer pulse exposures may generate pores of larger diameter enabling lateral diffusion of PS; whereas, smaller pores induced by fewer, lower amplitude and short pulse width exposures may only allow extracellular calcium and FM1-43 uptake.

  2. Oxygen and exposure kinetics as factors influencing the cytotoxicity of porfiromycin, a mitomycin C analogue, in Chinese hamster ovary cells.

    Science.gov (United States)

    Marshall, R S; Rauth, A M

    1988-10-15

    Some factors affecting the cytotoxicity of porfiromycin (PM), an analogue of mitomycin C (MMC), were investigated in suspension cultures of wild-type (AA8-4) and repair-deficient (UV-20) Chinese hamster ovary cells. Oxygen was an important modulator of PM toxicity in AA8-4 cells. The aerobic toxicity was significantly less, and toxicity under extremely hypoxic conditions was significantly greater for PM than MMC. Porfiromycin cytotoxicity at intermediate O2 levels was similar to that observed previously for MMC. While the aerobic/hypoxic ratio was greater for PM than MMC, survival at intermediate oxygen concentrations could limit the therapeutic utility of these drugs as adjuncts to radiotherapy. Ascorbic acid was found to increase the aerobic, but not hypoxic, cytotoxicity of PM in AA8-4 cells, as was observed previously for MMC. Investigation of various exposure times and drug concentrations revealed that drug toxicity for both aerobic and hypoxic cells was dependent on the product of drug concentration and time, and that the aerobic/hypoxic differential observed in AA8-4 cells was constant over a broad range of exposure conditions. The sensitivity of UV-20 cells was also a linear function of concentration and time, but no aerobic/hypoxic differential was observed in these cells. It is suggested that the sensitivity of UV-20 to PM and MMC, and its lack of an hypoxic/aerobic differential could result from lethality being due to a different lesion than in wild-type cells. PMID:3167822

  3. Cell proliferation as a requirement for development of the contact effect in Chinese hamster V79 spheroids

    International Nuclear Information System (INIS)

    Chinese hamster V79 cells grown for several hours in suspension culture form spheroids which are more resistant to killing by ionizing radiation than cells grown on petri dishes, a phenomenon known as the contact effect. Previous results using the alkali-unwinding assay as a measure of DNA damage have implicated differences in DNA conformation as contributing to this effect; spheroid DNA denatures more slowly in dilute alkali than monolayer DNA, perhaps due to the presence of constraints to DNA unwinding. In this paper, the rate of development of radiation resistance is shown to be similar when either cell survival or DNA unwinding is used as an end point. At the midpoint for development of resistance, approximately 10 h, the unwinding kinetics indicate that either half of the cells contain constraints to DNA unwinding, or half of the DNA in all of the cells contains constraints. The latter explanation appears more likely since all cells seem to develop these constraints at the same rate, regardless of position in the cell cycle or the degree of contact with other cells. Results using the microelectrophoresis assay to measure damage to individual nuclei confirm the fact that 10-h cultures show a homogeneous radiation response intermediate between that of monolayers and spheroids. Incubation of cells at room temperature or in the presence of drugs which inhibit cell cycle progression prevents full development of the contact effect. Conversely, incubation of cells in medium containing inhibitors of polyamine synthesis, adenylcyclase, glutathione synthesis, poly(ADP-ribose)polymerase, topoisomerase II, or cell-cell communication does not inhibit development of the contact effect as measured by DNA-unwinding kinetics

  4. Conditional expression of full-length humanized anti-prion protein antibodies in Chinese hamster ovary cells.

    Science.gov (United States)

    Mueller, Daniel A; Heinig, Lars; Ramljak, Sanja; Krueger, Astrid; Schulte, Reiner; Wrede, Arne; Stuke, Andreas W

    2010-12-01

    Because of their high antigen specificity and metabolic stability, genetically engineered human monoclonal antibodies are on the way to becoming one of the most promising medical diagnostics and therapeutics. In order to establish an in vitro system capable of producing such biosimilar antibodies, we used human constant chain sequences to design the novel human antibody expressing vector cassette pMAB-ABX. A bidirectional tetracycline (tet)-controllable promotor was used for harmonized expression of immunoglobulin type G (IgG) heavy and light chains. As an example we used anti-prion protein (anti-PrP) IgGs. Therefore, the variable heavy (V(H)) and light chain (V(L)) sequences of anti-PrP antibodies, previously generated in our laboratory by DNA immunization of prion protein knock-out mice, were isolated from murine hybridoma cell lines and inserted into pMAB-ABX vector. After transfection of Chinese hamster ovary (CHO) cells, a number of stable antibody producing cell clones were selected. One cell line (pMAB-ABX-13F10/3B5) stably expressing the recombinant humanized antibody (rechuAb) 13F10/3B5 was selected for detailed characterization by Western blot, immunofluorescence, and flow cytometric analyses. The full-length recombinant humanized IgG antibody showed a high level of expression in the cytoplasm. In conclusion, the new cell system described here is a suitable tool to produce functional intact full-length humanized IgG antibodies. PMID:21087094

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

    International Nuclear Information System (INIS)

    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 60Co 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)

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

    International Nuclear Information System (INIS)

    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

  7. 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

    OpenAIRE

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

    2011-01-01

    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®R3IGF-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) ...

  8. Genetic determinants of growth phase-dependent and adenovirus 5-responsive expression of the Chinese hamster thymidine kinase gene are contained within thymidine kinase mRNA sequences.

    OpenAIRE

    Lewis, J. A.; Matkovich, D A

    1986-01-01

    We have constructed a chimeric thymidine kinase (TK) minigene, pHe delta 6Ha, which combines the complete coding and 3' noncoding regions of a Chinese hamster TK cDNA with the promoter region and 5' untranslated region of the TK gene of herpes simplex virus type 1. We have transformed rat 4 cells to Tk+ with this gene and analyzed the pattern of TK gene expression in these transformants under various conditions of in vitro cell culture. We find that TK gene expression in these Tk+ transforman...

  9. Pharmacological characterization of extracellular acidification rate responses in human D2(long), D3 and D4.4 receptors expressed in Chinese hamster ovary cells

    OpenAIRE

    Coldwell, M C; Boyfield, I; Brown, A M; Stemp, G; Middlemiss, D. N.

    1999-01-01

    This study characterized pharmacologically the functional responses to agonists at human dopamine D2(long) (hD2), D3 (hD3) and D4.4 (hD4) zreceptors separately expressed in cloned cells using the cytosensor microphysiometer.Dopaminergic receptor agonists caused increases in extracellular acidification rate in adherent Chinese hamster ovary (CHO) clones expressing hD2, hD3 or hD4 receptors. Acidification rate responses to agonists in other cell lines expressing these receptors were smaller tha...

  10. Restoration of Chinese hamster cell radiation resistance by the human repair gene ERCC-5 and progress in molecular cloning of this gene

    International Nuclear Information System (INIS)

    The uv-sensitive Chinese hamster cell uv-135 is being used to identify and isolate the human gene, ERCC-5, which corrects nucleotide excision repair in this incision-defective mutant. A cosmid library, constructed from a 30 transformant of uv-135, has been screened for transfected gpt and human Alu family sequences. An ordered physical map of overlapping positives cosmids has been determined. Molecular evidence suggests a region of this map of <40 Kbp contains the ERCC-5 gene. 10 refs., 2 figs

  11. Differential toxicity of mitomycin C and porfiromycin to aerobic and hypoxic Chinese hamster ovary cells overexpressing human NADPH:cytochrome c (P-450) reductase.

    OpenAIRE

    Belcourt, M F; Hodnick, W F; Rockwell, S; Sartorelli, A C

    1996-01-01

    Purified NADPH:cytochrome c (P-450) reductase (FpT; NADPH-ferrihemoprotein oxidoreductase, EC 1.6.2.4) can reductively activate mitomycin antibiotics through a one-electron reduction to species that alkylate DNA. To assess the involvement of FpT in the intracellular activation of the mitomycins, transfectants overexpressing a human FpT cDNA were established from a Chinese hamster ovary cell line deficient in dihydrofolate reductase (CHO-K1/dhfr-). The parental cell line was equisensitive to t...

  12. A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins

    OpenAIRE

    Rocha H.A.O.; Franco C.R.C.; Trindade E.S.; Carvalho L.C.M.; Veiga S.S.; Leite E.L.; Dietrich C.P.; Nader H.B.

    2001-01-01

    Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). The effect of this polymer on adhesion p...

  13. Mechanism of action of cis-dichloro-bis (isopropylamine) trans dihydroxyplatinum IV (CHIP) on Chinese hamster and C3H mouse tumor cells and its interaction with x-irradiation

    International Nuclear Information System (INIS)

    CHIP acts as a hypoxic cell sensitizer when used in conjunction with x-irradiation. A change in the extrapolation number of the radiation survival curve of Chinese hamster ovary (CHO) cells is observed but the exponential slope (D0) remains the same. Chinese hamster ovary cells appear to be less sensitive than C3H mouse mammary tumor cells to CHIP. The type and level of chromosome aberrations observed in CHO cells indicate that the mechanism of action of CHIP is similar to that seen with bifunctional alkylating agents

  14. Role of 239Pu-induced chromosome alterations and mutated Ki-v-ras oncogene during liver-cancer induction in Chinese hamsters and mice

    International Nuclear Information System (INIS)

    Chromosome aberrations and mutated oncogenes can cause important changes during carcinogenesis. Model systems are being studied in which defined cellular and molecular changes can be quantitated and altered, and tumor frequency, type, and time of appearance can be evaluated. Dose-response relationships for Pu Citrate-induced chromosome aberrations and liver cancer were measured in Chinese hamsters. Chromosome aberrations increased linearly according to dose, with a slope of 4.8 x 10-1 aberrations/cell/Gy; liver-tumor incidence was 1.1 x 10-1 tumors/animal/Gy. The dose was calculated at the 50% survival time. The interaction between Pu and Ki-v-ras, an altered, dominant-acting oncogene, on the induction of liver cancer was measured in B6C3F1 mice. The neo oncogene was used as a negative control in these studies. The Ki-v-ras oncogene was inserted into a viral vector and incorporated into the livers of mice either 30 days before or after the incorporation of 239Pu. Compared with both the controls and the mice injected with a single insult, mortality increased in groups of animals that received combined exposure to oncogenes, CCl4, and 239Pu. The relationships between molecular and cellular damage and the induction of cancer is being defined in both mice and Chinese hamsters

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

    Directory of Open Access Journals (Sweden)

    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

  16. Cytotoxicity and DNA lesions produced by mitomycin C and porfiromycin in hypoxic and aerobic EMT6 and Chinese hamster ovary cells.

    Science.gov (United States)

    Fracasso, P M; Sartorelli, A C

    1986-08-01

    Solid neoplasms may contain deficient or poorly functional vascular beds, a property that leads to the formation of hypoxic tumor cells, which form a therapeutically resistant cell population within the tumor that is difficult to eradicate by ionizing irradiation and most existing chemotherapeutic agents. As an approach to the therapeutic attack of hypoxic cells, we have measured the cytotoxicity and DNA lesions produced by the bioreductive alkylating agents mitomycin C and porfiromycin, two structurally similar antibiotics, in oxygen-deficient and aerobic cells. Mitomycin C and porfiromycin were preferentially cytotoxic to hypoxic EMT6 cells in culture, with porfiromycin producing a greater differential kill of hypoxic EMT6 cells relative to their oxygenated counterparts than did mitomycin C. Chinese hamster ovary cells were more resistant to these quinone antibiotics; although in this cell line, porfiromycin was significantly more cytotoxic to hypoxic cells than to aerobic cells, and the degree of oxygenation did not affect the toxicity of mitomycin C. Alkaline elution methodology was utilized to study the formation of DNA single-strand breaks and DNA interstrand cross-links produced by mitomycin C and porfiromycin in both EMT6 and Chinese hamster ovary cells. A negligible quantity of DNA single-strand breaks and DNA interstrand cross-links were produced in hypoxic and aerobic Chinese hamster ovary cells by exposure to mitomycin C or porfiromycin, a finding consistent with the considerably lower sensitivity of this cell line to these agents. In EMT6 tumor cells, no single-strand breaks appeared to be produced by these antitumor antibiotics under both hypoxic and aerobic conditions; however, a significant number of DNA interstrand cross-links were formed in this cell line following drug treatment, with substantially more DNA interstrand cross-linking being produced under hypoxic conditions. Mitomycin C and porfiromycin caused the same amount of cross-linking under

  17. Measurement of DNA repair in Chinese hamster fibroblasts employing flow cytometry and monoclonal antibodies to DNA adducts

    International Nuclear Information System (INIS)

    The authors examined the utility of measuring DNA repair in single cells employing flow cytometric quantitation of fluorescent monoclonal antibodies directed against specific DNA adducts. Two antibodies were employed; the first directed against single strand (ss) bromodeoxyuridine (anti-BrdUrd) and the second against UV light induced ss-thymine dimers (anti-TT). Sensitivity with both monoclonals was highly dependent on DNA denaturation, with the most effective shown to be a 0.5N HCl histone extraction followed by 50% formamide for 30 min at 800C. Unscheduled synthesis following 30 J/m/sup 2/ UV irradiation in Gl/GO plateau phase CHO cells was demonstrated employing the anti-BrdUrd AB method combined with DNA counter-staining with propidium iodide. Data suggest that anti-BrdUrd Ab recognition of newly replicated sequences following UV irradiation may be strongly dependent on chromatin conformation. A linear correlation was observed for mean anti-TT AB fluorescence and UV dose up to a total of 3000 J/m/sup 2/. Also, a rapid reduction in cellular fluorescence, presumably reflecting dimer excision was observed when the cells were returned to 370C before fixation. Finally, data from various repair deficient CHO cells will be compared employing these methods

  18. Application of rapid-lysis techniques in radiobiology. IV. The effect of glycerol and DMSO on Chinese hamster cell survival and DNA single-strand break production

    International Nuclear Information System (INIS)

    A rapid-lysis technique has been used to compare the initial yield of DNA single-strand breaks (ssb) measured 0.2 sec after irradiation and cell survival for Chinese hamster cells in vitro. Both DMSO and glycerol protected cells irradiated in air, and there was a simple relationship between relative radiosensitivity and the initial number of ssb. Under oxic conditions at high concentrations (2 M) of either agent the yield of ssb was reduced by a factor of 3 and the slope of the survival curve by a factor of 2. Under hypoxic conditions much less protection was noted, and even at high concentrations of either agent (2 M) there was only a small degree of protection against cell inactivation and ssb

  19. Effect of combinations of nitroaromatic and nitroxyl radiosensitizers on the radiation survival response of Chinese hamster cells, V.79-753B, in vitro

    International Nuclear Information System (INIS)

    The effect of various combinations of nitroaromatic (electron-affinic) and nitroxyl (free-radical) radiosensitizers on the radiation survival response of hypoxic Chinese hamster cells, V.79-753B, was studied. A bifunctional sensitizer posessing both a free-radical and an electron-affinic nitroarene, 1-[1-oxyl-2,2,6,6-tetramethyl-4-piperidy]amino-3-[2-nitro-1-imidazolyl]-2-propanol (Ro-03-9454), was also used. In all combinations tested there was evidence that there is competition between the two types of sensitizer. This competition accounts for the mixed functional compound Ro-03-9454 being less effective than the monofunctional compound RSU-4013 (1-[1-[2-cyano-2-propyl]oxy-2,2,6,6- tetramethyl-4-piperidyl]amino-3-[2-nitro-1-imidazolyl]-2-propanol), which does not have a nitroxyl group. In combinations of nitroaromatic sensitizers the situation is more complex

  20. 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)

    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.)

  1. The effect of oxygen on low-dose hypersensitivity and increased radioresistance in Chinese hamster V79-379A cells

    International Nuclear Information System (INIS)

    Chinese hamster V79 cells irradiated in air are hypersensitive to X-ray doses less than 0.5 Gy and show an increased radioresistance over the dose range 0.5-1 Gy. Of considerable interest from both a mechanistic and clinical viewpoint is the response of hypoxic cells over this dose range. The data presented here indicate that hypoxic cells are also hypersensitive to low X-ray doses and exhibit an increased radioresistant response, albeit triggered at a somewhat higher dose (0.69 Gy, SEM ± 0.18 Gy) than observed in oxygenated cells (0.5 Gy, SEM ± 0.21 Gy). These data indicate that the triggering event for increased radioresistance may be independent of oxygen. As reported by others previously, the oxygen enhancement ratio was found to decrease with a decreasing X-ray dose. 21 refs., 3 figs., 1 tab

  2. Effects of pre-ovulatory X-irradiation on fertilization, initial cleavage and post-nidation development in the Chinese hamster

    International Nuclear Information System (INIS)

    In order to investigate the effects of pre-ovulation X-ray radiation on fertilization, initial cleavage and post-nidation development, Chinese hamster dams were mated with normal males after exposure to 200 rads of radiation during the primary maturation period, and cytogenetic studies were performed at 2.5, 3.5 and 10 days after fertilization; comparison studies were also performed on an untreated control group. The results indicated that: (1) The ovarian ova with chromosomal anomalies induced by X-ray radiation had the ability to be fertilized and transmit the abnormality to the 2-celled stage, but most of them deceased by the 8-celled stage. (2) The embryos attaining the 8-celled stage with normal chromosomes were implanted and survived, but showed remarkable hypoplasia on day 10 of gestation. (author)

  3. A fluence response study of lethality and mutagenicity of white, black, and blue fluorescent light, sunlamp, and sunlight irradiation in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Under a set of defined experimental conditions, the fluence response of Chinese hamster ovary (CHO) cells to various light sources was studied by measuring single-cell survival and mutation to 6-thioguanine (TG) resistance. Fluorescent white, black, and blue lights were slightly lethal and mutagenic. Sunlamp light was highly lethal and mutagenic, exhibiting these biological effects within 15 sec of exposure under conditions recommended by the manufacturer for human use. Lethal and mutagenic effects were observed after 5 min of sunlight exposure; responses varied with hourly and daily variations in solar radiation. Sunlight induced TG-resistant variants possessed <5% of parental cellular hypoxanthine-guanine phosphoribosyl transferase (HGPRT) enzyme activity, suggesting that the mutation induction occurs at this locus. The cell survival and mutation-induction curves generated by exposure of cells to both sunlamp and sunlight were similar to those obtained by the use of a standard far-UV lamp

  4. 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)

    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

  5. Induction and phosphorylation of protein kinase C-α and mitogen-activated protein kinase by hypoxia and by radiation in Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Protein kinase C (PKC) and mitogen-activated protein (MAP) kinase are protein-serine/threonine kinases which are important regulators of diverse cellular processes including metabolism, proliferation and differentiation. This study shows that both hypoxia and X irradiation of serum-deprived Chinese hamster V79 cells cause the induction and phosphorylation of the PKC-α isoform. The increased induction and phosphorylation of PKC occur mainly in the nuclear fraction. Unlike the PKC activator TPA, neither hypoxic nor radiation stress causes translocation of PKC-α from the cytosol to the membrane. The induction of PKC-α by hypoxia is accompanied by an increased expression of MAP kinase but, in contrast, this does not occur when PKC-α is induced by radiation. Radiation, like TPA, causes a complete redistribution of MAP kinase from the cytosol to the nucleus. 28 refs., 7 figs

  6. 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)

    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 Man9GlcNAc2 and Man5GlcNAc2 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 P212121 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

  7. Fibroblast receptor for cell-substratum adhesion: studies on the interaction of baby hamster kidney cells with latex beads coated by cold insoluble globulin (plasma fibronectin)

    OpenAIRE

    1980-01-01

    Studies were carried out on the interactions of uncharged latex beads (0.76 micrometer) with baby hamster kidney cells. Binding of beads to the cells occurred if the beads were coated by cold insoluble globulin (CIG) (plasma fibronectin) but not if the beads were coated by bovine albumin. Bovine albumin-coated beads did not bind to the cells even in the presence of excess CIG in the incubation medium. Binding of beads occurred randomly over the entire surfaces of cells in suspension. However,...

  8. 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

    OpenAIRE

    Jacqueline D. Caffetti; Mário S. Mantovani; María C. Pastori; Alberto S. Fenocchio

    2008-01-01

    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 (Cri...

  9. 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.

  10. Expression of human α2-macroglobulin cDNA in baby hamster kidney fibroblasts: Secretion of high levels of active α2-macroglobulin

    International Nuclear Information System (INIS)

    Human α2-macroglobulin (α2M) is a unique 720-kDa proteinase inhibitor with a broad specificity. Unlike most other proteinase inhibitors, it does not inhibit proteolytic activity by blocking the active site of the proteinase. During complex formation with a proteinase α2M entraps the proteinase molecule in a reaction that involves large conformational changes in α2M. The authors describe the molecular cloning of α2M cDNA from the human hepatoblastoma cell line HepG2. The cDNA was subcloned under control of the adenovirus major late promoter in a mammalian expression vector and introduced into the baby hamster kidney (BHK) cell line. Transformed clones were isolated and tested for production of human α2M with a specific enzyme-linked immunosorbent assay. Human recombinant α2M (rα2M), secreted and purified form isolated transfected BHK cell lines, was structurally and functionally compared to α2M purified from human serum. The results show that rα2M was secreted from the BHK cells as an active proteinase-binding tetramer with functional thiol esters. Cleavage reactions of rα2M with methylamine and trypsin showed that the recombinant product, which was correctly processed at the N-terminus, exhibited molecular characteristics similar to those of the human serum derived reference

  11. A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins

    Directory of Open Access Journals (Sweden)

    Rocha H.A.O.

    2001-01-01

    Full Text Available Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1 and the mutant type deficient in xylosyltransferase (CHO-745. The effect of this polymer on adhesion properties with specific extracellular matrix components was studied using several matrix proteins as substrates for cell attachment. Treatment with the polymer inhibited the adhesion of fibronectin to both CHO-K1 (2 x 10(5(and CHO-745 (2 x 10(5 and 5 x 10(5 cells. No effect was detected with laminin, using the two cell types. On the other hand, adhesion to vitronectin was inhibited in CHO-K1 cells and adhesion to type I collagen was inhibited in CHO-745 cells. In spite of this inhibition, the fucan did not affect either cell proliferation or cell cycle. These results demonstrate that this polymer is a new anti-adhesive compound with potential pharmacological applications.

  12. GeneOptimizer program-assisted cDNA reengineering enhances sRAGE autologous expression in Chinese hamster ovary cells.

    Science.gov (United States)

    Wei, Wen; Kim, Ji Min; Medina, Danny; Lakatta, Edward G; Lin, Li

    2014-03-01

    Soluble receptor for advanced glycation end products (sRAGE) is a secreted mammalian protein that functions as a decoy to counter-react RAGE signaling-resultant pathological conditions, and has high therapeutic potentials. Our prior studies showed that recombinant human sRAGE expressed in Chinese hamster, Ceanothus griseus, ovary (CHO) cells is modified by specific N-glycosylation, and exhibits higher bioactivity than that expressed in other host systems including insect Spodoptera frugiperda cells. Here, we show that GeneOptimizer software program-assisted, reengineered sRAGE cDNA enhances the recombinant protein expression in CHO cells. The cDNA sequence encoding human sRAGE was optimized for RNA structure, stability, and codon usages in CHO cells. We found that such optimization augmented sRAGE expression over 2 folds of its wild-type counterpart. We also studied how individual parameter impacted sRAGE autologous expression in CHO cells, and whether sRAGE bioactivity was compromised. We found that the enhanced expression appeared not to affect sRAGE N-glycosylation and bioactivity. Optimization of sRAGE expression provides a basis for future large-scale production of this protein to meet medical needs. PMID:24373844

  13. The zinc ionophore clioquinol reverses autophagy arrest in chloroquine-treated ARPE-19 cells and in APP/mutant presenilin-1-transfected Chinese hamster ovary cells.

    Science.gov (United States)

    Seo, Bo-Ra; Lee, Sook-Jeong; Cho, Kyung Sook; Yoon, Young Hee; Koh, Jae-Young

    2015-12-01

    Arrested autophagy may contribute to the pathogenesis of Alzheimer's disease. Because we found that chloroquine (CQ) causes arrested autophagy but clioquinol (ClioQ), a zinc ionophore, activates autophagic flux, in the present study, we examined whether ClioQ can overcome arrested autophagy induced by CQ or mutant presenilin-1 (mPS1). CQ induced vacuole formation and cell death in adult retinal pigment epithelial (ARPE-19) cells, but co-treatment with ClioQ attenuated CQ-associated toxicity in a zinc-dependent manner. Increases in lysosome dilation and blockage of autophagic flux by CQ were also markedly attenuated by ClioQ treatment. Interestingly, CQ increased lysosomal pH in amyloid precursor protein (APP)/mPS1-expressing Chinese hamster ovary 7WΔE9 (CHO-7WΔE9) cell line, and ClioQ partially re-acidified lysosomes. Furthermore, accumulation of amyloid-β (Aβ) oligomers in CHO-7WΔE9 cells was markedly attenuated by ClioQ. Moreover, intracellular accumulation of exogenously applied fluorescein isothiocyanate-conjugated Aβ(1-42) was also increased by CQ but was returned to control levels by ClioQ. These results suggest that modulation of lysosomal functions by manipulating lysosomal zinc levels may be a useful strategy for clearing intracellular Aβ oligomers. PMID:26453000

  14. Understanding the intracellular effects of yeast extract on the enhancement of Fc-fusion protein production in Chinese hamster ovary cell culture.

    Science.gov (United States)

    Hu, Dongdong; Sun, Yating; Liu, Xuping; Liu, Jintao; Zhang, Xintao; Zhao, Liang; Wang, Haibin; Tan, Wen-Song; Fan, Li

    2015-10-01

    Yeast extract (YE), as a non-animal source additive for mammalian cell culture medium, has been widely used for manufacturing of therapeutic proteins. In the present study, one particular YE was found to have significantly improved the specific productivity (q p) of Fc-fusion protein in recombinant Chinese hamster ovary (rCHO) cell culture. In order to elucidate the intracellular effects of YE on protein productivity, steps of the target protein synthesis process were investigated to unveil their variations caused by YE addition. Stepwise analysis on Fc-fusion protein synthesis process showed that YE enhanced Fc-fusion protein gene transcription with cell cycle arrest at G1 phase; mammalian target of rapamycin (mTOR) signaling pathway was activated to enhance the translation of Fc-fusion protein, and the block in post-translational steps of Fc-fusion protein was alleviated by YE addition as well. Our results revealed the responses of multiple protein production steps to the addition of YE and provided a practical guidance for the separation and application of active compounds from hydrolysates. PMID:26162671

  15. Inhibition of X-ray-induced potentially lethal damage (PLD) repair in aerobic plateau-phase Chinese hamster cells by misonidazole

    International Nuclear Information System (INIS)

    The effect of the 2-nitroimidazole radiosensitizer misonidazole (MISO) and the hydrophilic analog SR-2508 on the repair of X-ray-induced potentially lethal damage (PLD) was studied in plateau-phase Chinese Hamster ovary (HA-1) cells. It was found that although MISO does not radiosensitize aerobic cells, it inhibits the repair of PLD. However, under hypoxic conditions, MISO has no effect on PLD repair. The major portion of the inhibition of PLD repair in aerobic cells requires the presence of MISO only during irradiation; little or no additional inhibition occurs when MISO is present during the postirradiation repair period. Also, treatment of aerobic cells with 5 mM MISO for either 5 or 30 min prior to irradiation is equally inhibitory. This suggests that the presence of MISO in some way modifies the initial lesion under aerobic conditions since it does not increase cell killing as determined by immediate plating but inhibits subsequent repair. The inhibition is concentration dependent; 0.5 mM MISO inhibits PLD repair by one-half while 5-10 mM totally inhibits the repair measured 6 hr postirradiation. This phenomenon suggests that radiosensitization of tissue in vivo by MISO and other 2-nitroimidazoles may not be unequivocal proof of the presence of hypoxic cells

  16. Phosphatidylserine biosynthesis in cultured Chinese hamster ovary cells. I. Inhibition of de novo phosphatidylserine biosynthesis by exogenous phosphatidylserine and its efficient incorporation

    International Nuclear Information System (INIS)

    The effect of phosphatidylserine exogenously added to the medium on de novo biosynthesis of phosphatidylserine was investigated in cultured Chinese hamster ovary cells. When cells were cultured for several generations in medium supplemented with phosphatidylserine and 32Pi, the incorporation of 32Pi into cellular phosphatidylserine was remarkably inhibited, the degree of inhibition being dependent upon the concentration of added phosphatidylserine. 32Pi uptake into cellular phosphatidylethanolamine was also partly reduced by the addition of exogenous phosphatidylserine, consistent with the idea that phosphatidylethanolamine is biosynthesized via decarboxylation of phosphatidylserine. However, incorporation of 32Pi into phosphatidylcholine, sphingomyelin, and phosphatidylinositol was not significantly affected. In contrast, the addition of either phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, or phosphatidylinositol to the medium did not inhibit endogenous biosynthesis of the corresponding phospholipid. Radiochemical and chemical analyses of the cellular phospholipid composition revealed that phosphatidylserine in cells grown with 80 microM phosphatidylserine was almost entirely derived from the added phospholipid. Phosphatidylserine uptake was also directly determined by using [3H]serine-labeled phospholipid. Pulse and pulse-chase experiments with L-[U-14C] serine showed that when cells were cultured with 80 microM phosphatidylserine, the rate of synthesis of phosphatidylserine was reduced 3-5-fold. Enzyme assaying of extracts prepared from cells grown with and without phosphatidylserine indicated that the inhibition of de novo phosphatidylserine biosynthesis by the added phosphatidylserine appeared not to be caused by a reduction in the level of the enzyme involved in the base-exchange reaction between phospholipids and serine

  17. [Analysis of the transcriptional profiling of cell cycle regulatory networks of recombinant Chinese hamster ovary cells in batch and fed-batch cultures].

    Science.gov (United States)

    Liu, Xingmao; Ye, Lingling; Liu, Hong; Li, Shichong; Wang, Qiwei; Wu, Benchuan; Chen, Zhaolie

    2011-08-01

    In the light of Chinese hamster ovary (CHO) cell line 11G-S expressing human recombinant pro-urokinase, the differences of gene expression levels of the cells in different growth phases in both batch and fed-batch cultures were revealed by using gene chip technology. Then, based on the known cell cycle regulatory networks, the transcriptional profiling of the cell cycle regulatory networks of the cells in batch and fed-batch cultures was analyzed by using Genmapp software. Among the approximate 19 191 target genes in gene chip, the number of down-regulated genes was more than those of up-regulated genes of the cells in both batch and fed-batch cultures. The number of down-regulated genes of the cells in the recession phase in fed-batch culture was much more than that of the cells in batch culture. Comparative transcriptional analysis of the key cell cycle regulatory genes of the cells in both culture modes indicated that the cell proliferation and cell viability of the cells in both batch and fed-batch cultures were mainly regulated through down-regulating Cdk6, Cdk2, Cdc2a, Ccne1, Ccne2 genes of CDKs, Cyclin and CKI family and up-regulating Smad4 gene. PMID:22097809

  18. 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.

  19. 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)

    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

  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.

    Science.gov (United States)

    Holmes, Amie L; Joyce, Kellie; Xie, Hong; Falank, Carolyne; Hinz, John M; Wise, John Pierce

    2014-04-01

    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. PMID:24561002

  1. Template properties and repair of a newly synthesized DNA in UV-sensitive clones of the Chinese hamster after UV irradiation

    International Nuclear Information System (INIS)

    UV effect on the DNA template activity has been studied by in vitro RNA synthesis with DNA dependent RNA polymerase from E. coli. DNA was isolated from Chinese hamster UV-resistant clone V79 and UV-sensitive clone CHS2. 10 Jm-2 of UV causes a 60% reduction in the DNA template activity in both clones. 3 h postirradiation incubation leads to a complete recovery of the DNA template activity in V79 cells contrary to a 15% recovery in mutant cells. Data obtained on the recovery of the molecular mass of a newly synthesized DNA by ultracentrifugation in alkaline sucrose gradients point to 'bypass' of lesions - synthesis of the daughter DNA without gaps - in V79 cells. Unlike V79 cells there is no 'bypass' of lesions (pyrimidine dimers) in CHS2 cells. The results suggest a positive correlation between the recovery of DNA template activity and the daughter DNA synthesis without gaps. These two properties may result from conformation repair of the damaged template in the UV-resistant clone and deficiency of the process in the UV-sensitive clone. (author)

  2. Absence of late effects on survival and developmental abilities of pachytene oocytes X-irradiated during neonatal stages in the Chinese hamster

    International Nuclear Information System (INIS)

    In neonatal Chinese hamsters, all oocytes on day O after birth are at pachytene and ovarian X-irradiation with 1 Gy causes no acute oocyte killing. Identical treatment on day 4, however, kills all diplotene-dictyate oocytes within 48 h, and consequently only a small number of pachytene oocytes survives. Late effects of X-rays on the pachytene oocytes were investigated in relation to the reproductive capacity of irradiated females. There was no difference between the O-day irradiated females and controls with respect to age of sexual maturation, fertility span and rate of age-dependent reduction in the number of oocytes due to follicular atresia, but 4-day irradiated females showed a marked delay in sexual maturation and a very precocious cessation of oestrous cycles. However, the degeneration of the surviving oocytes was not accelerated. Fertility tests on day 18.5 of gestation revealed no difference between both irradiated groups and controls with respect to the mean number of corpora lutea and the occurrence of dead and abnormal conceptuses. These results indicated clearly that pachytene oocytes were not affected by acute or late effects of X-rays although the dose was high enough to kill diplotene-dictyate oocytes completely. (U.K.)

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

    International Nuclear Information System (INIS)

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO2) and aluminium oxide (Al2O3) 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 μg/mL TiO2 and 0.5-10 μg/mL Al2O3. SCE frequencies were higher for cells treated with 1-5 μg/mL TiO2. The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO2. No SCE induction was achieved after treatment with 1-25 μg/mL Al2O3. In conclusion, findings showed cytotoxic and genotoxic effects of TiO2 and Al2O3 NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  4. A simple and reliable in vitro test system for the analysis of induced aneuploidy as well as other cytogenetic end-points using Chinese hamster cells

    International Nuclear Information System (INIS)

    Although aneuploidy is a serious human health problem, the experimental methodology devised until now to study the mechanisms involved in the induction of aneuploidy and for the screening of aneuploidy-inducing agents has not been so much employed to have the necessary validation. A procedure using primary cell cultures of Chinese hamster embryo cells grown on cover glasses is described. To avoid the excessive scattering and subsequent loss of chromosomes, a hypotonic treatment with a 0.17% sodium chloride solution, at room temperature, followed by in situ fixation has been standardized. This procedure improves the method through the reduction of the spontaneous frequency of aneuploid cells. Experiments carried out with cells treated with X-rays, X-rays plus caffeine, and the synthetic estrogen diethylstilbestrol (DES) demonstrated the accuracy of the system since the average chromosome number remained constant in spite of the induction of high frequencies of aneuploid cells. Moreover, the method allows for the analysis of other cytogenetic endpoints such as anaphase-telophase alterations, structural chromosome aberrations or sister chromatid exchanges. (author)

  5. Differential toxicity of mitomycin C and porfiromycin to aerobic and hypoxic Chinese hamster ovary cells overexpressing human NADPH:cytochrome c (P-450) reductase.

    Science.gov (United States)

    Belcourt, M F; Hodnick, W F; Rockwell, S; Sartorelli, A C

    1996-01-01

    Purified NADPH:cytochrome c (P-450) reductase (FpT; NADPH-ferrihemoprotein oxidoreductase, EC 1.6.2.4) can reductively activate mitomycin antibiotics through a one-electron reduction to species that alkylate DNA. To assess the involvement of FpT in the intracellular activation of the mitomycins, transfectants overexpressing a human FpT cDNA were established from a Chinese hamster ovary cell line deficient in dihydrofolate reductase (CHO-K1/dhfr-). The parental cell line was equisensitive to the cytotoxic action of mitomycin C under oxygenated and hypoxic conditions. In contrast, porfiromycin was considerably less cytotoxic to wild-type parental cells than was mitomycin C in air and markedly more cytotoxic under hypoxia. Two FpT-transfected clones were selected that expressed 19- and 27-fold more FpT activity than the parental line. Levels of other oxidoreductases implicated in the activation of the mitomycins were unchanged. Significant increases in sensitivity to mitomycin C and porfiromycin in the two FpT-transfected clones were seen under both oxygenated and hypoxic conditions, with the increases in toxicity being greater under hypoxia than in air. These findings demonstrate that FpT can bioreductively activate the mitomycins in living cells and implicate FpT in the differential aerobic/hypoxic toxicity of the mitomycins. PMID:8552660

  6. The intracellular location of NADH:cytochrome b5 reductase modulates the cytotoxicity of the mitomycins to Chinese hamster ovary cells.

    Science.gov (United States)

    Belcourt, M F; Hodnick, W F; Rockwell, S; Sartorelli, A C

    1998-04-10

    NADH:cytochrome b5 reductase activates the mitomycins to alkylating intermediates in vitro. To investigate the intracellular role of this enzyme in mitomycin bioactivation, Chinese hamster ovary cell transfectants overexpressing rat NADH:cytochrome b5 reductase were generated. An NADH:cytochrome b5 reductase-transfected clone expressed 9-fold more enzyme than did parental cells; the levels of other mitomycin-activating oxidoreductases were unchanged. Although this enzyme activates the mitomycins in vitro, its overexpression in living cells caused decreases in sensitivity to mitomycin C in air and decreases in sensitivity to porfiromycin under both air and hypoxia. Mitomycin C cytotoxicity under hypoxia was similar to parental cells. Because NADH:cytochrome b5 reductase resides predominantly in the mitochondria of these cells, this enzyme may sequester these drugs in this compartment, thereby decreasing nuclear DNA alkylations and reducing cytotoxicity. A cytosolic form of NADH:cytochrome b5 reductase was generated. Transfectants expressing the cytosolic enzyme were restored to parental line sensitivity to both mitomycin C and porfiromycin in air with marked increases in drug sensitivity under hypoxia. The results implicate NADH:cytochrome b5 reductase in the differential bioactivation of the mitomycins and indicate that the subcellular site of drug activation can have complex effects on drug cytotoxicity. PMID:9535868

  7. Survival and mutation in clones derived from V79 Chinese hamster cells irradiated with multiple small exposures to far-UV and mid-UV

    International Nuclear Information System (INIS)

    Clones were isolated from U81 and N80 cells that were established by irradiation of Chinese hamster V79-M12G cells on a once a day schedule with 81 and 80 fractions of 6 J m/sup -2/ far-UV and 150 Jm/sup -2/ mid-UV (UV-B), respectively. These clones were examined for UV sensitivity to cell lethality and induction of mutations at 6TG/sup r/ (resistance to 6-thioguanine) and Oua/sup R/ (resistance to ouabain) loci. Survival curves for these clones indicate that their UV sensitivities to lethality vary from that of M12G cells to that of U81 and N80 parental cells. Clones also show heterogeneity for mutability to mid-UV: For induction of 6TG/sup r/, for example, non-mutable (U814), hypomutable (U815) and hypermutable (U811) were isolated from U81 cells. The authors are investigating by chromosome analysis and repair experiments why resistance to far-UV and mid-UV cell killing in these cells appears to be induced but the resulting survivors have a heterogeneous response to mutation induction by further doses of UV light

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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.)

  10. Relationship between Fluorescence Intensity of GFP and the Expression Level of Prestin in a Prestin-Expressing Chinese Hamster Ovary Cell Line

    Science.gov (United States)

    Iida, Koji; Nagaoka, Tomoyuki; Tsumoto, Kouhei; Ikeda, Katsuhisa; Kumagai, Izumi; Kobayashi, Toshimitsu; Wada, Hiroshi

    Outer hair cells (OHCs) in mammals can elongate and contract at frequencies up to 100kHz in response to changes in their membrane potential. The origin of this unique motility is the motor protein prestin, which is densely packed in the lateral membrane of the OHCs. In a previous work, we constructed a prestin-expressing cell line using Chinese hamster ovary (CHO) cells to obtain a stable supply of prestin. When we research prestin using constructed cells, it is necessary to estimate the expression level of prestin in the cells easily and non-invasively. As the prestin gene and a green fluorescent protein (GFP) gene were introduced into constructed cells using the same vector, the expression level of prestin and fluorescence intensity of GFP are possibly correlated. Since this correlation is not clear, however, in this study, we therefore investigated whether the expression level of prestin evaluated by patch-clamp recording and the fluorescence intensity of GFP obtained from fluorescence images are correlated or not. As a result, it was demonstrated that they were correlated. The expression level of prestin can therefore be evaluated by measuring the fluorescence intensity of GFP.

  11. Effect of vitamin E on cytotoxicity, DNA single strand breaks, chromosomal aberrations, and mutation in Chinese hamster V-79 cells exposed to ultraviolet-B light

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, M.; Tsuzuki, K.; Matsumoto, K.; Ogura, R. (Kurume Univ., Fukuoka (Japan). School of Medicine)

    1992-07-01

    The effect of pretreatment with vitamin E on cytotoxicity, DNA single strand breaks, and chromosomal aberrations as well as on mutation induced by ultraviolet-B light (UV-B) was investigated in Chinese hamster V-79 cells. Cellular pretreatment with non-toxic levels of 25 {mu}M {alpha}-tocopherol succinate (vitamin E) for 24h prior to exposure resulted in a 10-fold increase in cellular levels of {alpha}-tocopherol. Using a colony-forming assay, this pretreatment decreased the cytotoxicity of UV-B light. However, alkaline elution assays demonstrated that pretreatment with vitamin E did not affect the number of DNA single strand breaks caused by UV-B light. UV-B exposure produced a dose-dependent induction of chromosomal aberrations and mutations at the HGPRT locus, and neither of these actions of UV-B was influenced by pretreatment with the vitamin. These results suggest that vitamin E protects cells from UV-B-induced cytotoxicity, possibly through its ability to scavenge free radicals. The genotoxicity induced by UV-B light may not correlate directly with the cytotoxic action of this wavelength region in sunlight. (author).

  12. Effect of vitamin E on cytotoxicity, DNA single strand breaks, chromosomal aberrations, and mutation in Chinese hamster V-79 cells exposed to ultraviolet-B light

    International Nuclear Information System (INIS)

    The effect of pretreatment with vitamin E on cytotoxicity, DNA single strand breaks, and chromosomal aberrations as well as on mutation induced by ultraviolet-B light (UV-B) was investigated in Chinese hamster V-79 cells. Cellular pretreatment with non-toxic levels of 25 μM α-tocopherol succinate (vitamin E) for 24h prior to exposure resulted in a 10-fold increase in cellular levels of α-tocopherol. Using a colony-forming assay, this pretreatment decreased the cytotoxicity of UV-B light. However, alkaline elution assays demonstrated that pretreatment with vitamin E did not affect the number of DNA single strand breaks caused by UV-B light. UV-B exposure produced a dose-dependent induction of chromosomal aberrations and mutations at the HGPRT locus, and neither of these actions of UV-B was influenced by pretreatment with the vitamin. These results suggest that vitamin E protects cells from UV-B-induced cytotoxicity, possibly through its ability to scavenge free radicals. The genotoxicity induced by UV-B light may not correlate directly with the cytotoxic action of this wavelength region in sunlight. (author)

  13. Chromium(VI)-induced Production of Reactive Oxygen Species, Change of Plasma Membrane Potential and Dissipation of Mitochondria Membrane Potential in Chinese Hamster Lung Cell Cultures

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To examine whether Reactive Oxygen Species (ROS) is generated, and whether plasma membrane potential and mitochondrial membrane potential are depolarized in Chinese Hamster Lung (CHL) cell lines exposed to Cr (VI). Methods CHL cells were incubated with Cr(VI) at 10 μmol/L, 2.5 μmol/L, 0.65 μmol/L for 3 and 6 hours, respectively. The production of ROS was performed by using 2,7_dichlorofluorescin diacetate; The changes in plasma membrane potential were estimated using fluorescent cationic dye DiBAC4; And the changes in mitochondria membrane potential were estimated using fluorescent dye Rhodamine 123. Results The ROS levels in CHL cells increased in all treated groups compared with the control group (P<0.01); The plasma membrane potential and mitochondrial membrane potential in CHL cells dissipated after incubated with Cr(VI) at 10 μmol/L for 3 hours and 6 hours (P<0.01), at 2.5 μmol/L for 6 hours (P<0.01 or 0.05). Conclusion Cr(VI) causes the dissipation of plasma membrane potential and mitochondrial membrane potential in CHL cell cultures, and Cr(VI)_induced ROS may play a role in the injuries.

  14. Chromium(VI)—induces Production of Reactive Oxygen Species,Change of Plasma Membrane Potential and Dissipation of Mitochondria Membrane otential in Chinese Hamster Lung Cell Cultures

    Institute of Scientific and Technical Information of China (English)

    XIEYI; ZHUANGZHI-XIONG

    2001-01-01

    Objective:To examine whether Reactive Oxygen Species(ROS) is generated,and whether plasma membrane potential and mitochnodrial membrane potential are depolarized in Chinese Hamster Lung(CHL)cell lines exposed to Cr(VI),Methods:CHL Cells were incubated with Cr(VI) at 10 umol/L,2.5umol/L,0.65umol/L for 3 and 6 hours,respectively.The rpoduction of ROS was performed by using 2,7-dichlorofluorescin discetate;The changes in plasma membrane potential were performed by using 2,7-dichlorofluorescin discetate;The changes in plasma membrane potential were performed by using 2,7-dichlorofluorescin diacetate;The changes in plasma membrane potential were estimated using fluorescent cationic dye DiBAC4;And the changes in mitochondria membrane potential were estimated using fluorescent dye Rhodamine 123,Results:The ROS levels in CHL cells increased in all treated groups compared with the control group(P<0.01);The plasma membrane potential and mitochondrial membrane potential in CHL cells dissipated after incubated with Cr(VI) at 10umol/L for 3 hours and 6 hours(P<0.01),at 2.5umol/L for 6 hours(P<0.01 or 0.05),Conclusion:Cr(VI) causes the dissipation of plasma membrane potential and mitochnodrial membrane otential in CHL cell cultrues,and Cr(VI)-induced ROS may play a role in the injuries.

  15. 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

    2016-01-01

    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 (culture media. In a fed-batch process of manufacturing scale bioreactors, two distinguished trends for changes in amino acid concentrations were identified in response to feeding. Ten essential amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 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. PMID:26355770

  16. Microencapsulation of human diploid fibroblasts in cationic polyacrylates.

    Science.gov (United States)

    Mallabone, C L; Crooks, C A; Sefton, M V

    1989-08-01

    Human diploid fibroblasts and Chinese hamster ovary cells were encapsulated in several copolymers of dimethylaminoethyl methacrylate with methacrylic acid and/or methyl methacrylate. Copolymers containing 16 to 25% dimethylaminoethyl methacrylate and less than or equal to 2.2% methacrylic acid (based on monomer mol%) supported human diploid fibroblast growth when the polymer was cast as a film on glass or polystyrene. The cells survived encapsulation and grew, but growth was only observed in those capsules which appeared to be flawed; the flaws were detected as an early loss of fluorescence, due to leakage of the FITC-dextran added as a marker to the encapsulated cell suspension. Presumably the capsule wall had too low a permeability to allow for unrestricted growth. Chinese hamster ovary cells behaved similarly in dimethylaminoethyl methacrylate/methyl methacrylate capsules. Increasing the water content, by addition of methacrylic acid, did not improve matters, since these materials were not as good a substrate for cell growth as the others. Preparing materials that are sufficiently permeable, with low toxicity and high processability and which support the growth of anchorage-dependent cells is difficult, yet it remains an appropriate goal for further study. PMID:2804227

  17. Onderzoek naar de inductie van chromosoomafwijkingen en "sister- chromatid exchanges" door vinylacetaat met Chinese hamster cellen in vitro

    OpenAIRE

    Knaap, van der, J.A.; A.G.A.C.; Bergkamp; W.G.M.; Groot, de, C.P.G.M.; M.G.

    1986-01-01

    Vinylacetaat bleek een clastogene werking te hebben in een test op chromosoomafwijkingen met Chinese hamstercellen in vitro vanaf 0,25 mmol/l zowel in aan- als in afwezigheid van een systeem voor metabolische activering (S9). Tevens induceerde vinylacetaat in deze cellen een sifnificante toename in het aantal zuster-chromatide uitwisselingen (SCE's) per cel, zowel in aan als in afwezigheid van een systeem voor metabolische activering (S9) bij concentraties van 0,03125 ul/ml (respectievel...

  18. Content of Androgen Receptor in Cultured Genital Skin Fibroblast From Different Ages of Chinese Normal Men

    Institute of Scientific and Technical Information of China (English)

    卢建; 何立敏; 张金山; 杨震; 周云

    1995-01-01

    A ratpid, simple, reliable method is described for assaying androgen receptor (AR) in dispersed, whole, cultured human genital skin fibroblasts (GSF) with a synthetic androgen, 3H-methyltrienolone (3H-R1881). Receptors for androgen in GSF exhiblt high affinity (Kd=3.0±0.1 nmol/L), low binding capacity and androgen specificity. The content of AR in cultured GSF from 40 normal men varying in age from 1.5—60 years u:as also investigated by this assay. Scatchard analysis and slngle plot revealed the presence of 4.500-8500 binding sites per cell, mean number of AR in GSF of these men is 6288±1082 binding sites/cell. No significant difference was observed in the content of AR in different age groups. This result showed that the content of AR in these ceils did not change with age.

  19. Chemometrics and in-line near infrared spectroscopic monitoring of a biopharmaceutical Chinese hamster ovary cell culture: prediction of multiple cultivation variables.

    Science.gov (United States)

    Clavaud, Matthieu; Roggo, Yves; Von Daeniken, Ralph; Liebler, André; Schwabe, Jan-Oliver

    2013-07-15

    In the present study near infrared (NIR) spectroscopy was used to monitor the cultivation of mammalian Chinese hamster ovary (CHO) cells producing a monoclonal antibody in a fed-batch cell culture process. A temperature shift was applied during the cultivation. The cells were incubated at 37 °C and 33 °C. The Fourier transform near infrared (FT-NIR) multiplex process analyzer spectroscopy was investigated to monitor cultivation variables of the CHO cell culture from 10 independent batches using two channels of the FT-NIR. The measurements were performed on production scale bioreactors of 12,500 L. The cell cultures were analyzed with the spectrometer coupled to a transflection sterilizable fiber optic probe inserted into the bioreactors. Multivariate data analysis (MVDA) employing unsupervised principal component analysis (PCA) and partial least squares regression methods (PLS) were applied. PCA demonstrated that 96% of the observed variability was explained by the process trajectory and the inter-batch variability. PCA was found to be a significant tool in identifying batch homogeneity between lots and in detecting abnormal fermentation runs. Seven different cell culture parameters such as osmolality, glucose concentration, product titer, packed cell volume (PCV), integrated viable packed cell volume (ivPCV), viable cell density (VCD), and integrated viable cell count (iVCC) were monitored inline and predicted by NIR. NIR spectra and reference analytics data were computed using control charts to evaluate the monitoring abilities. Control charts of each media component were under control by NIR spectroscopy. The PLS calibration plots offered accurate predictive capabilities for each media. This paper underlines the capability for inline prediction of multiple cultivation variables during bioprocess monitoring. PMID:23622522

  20. Changes in the Number of Double-Strand DNA Breaks in Chinese Hamster V79 Cells Exposed to γ-Radiation with Different Dose Rates

    Directory of Open Access Journals (Sweden)

    Andreyan N. Osipov

    2013-07-01

    Full Text Available A comparative investigation of the induction of double-strand DNA breaks (DSBs in the Chinese hamster V79 cells by γ-radiation at dose rates of 1, 10 and 400 mGy/min (doses ranged from 0.36 to 4.32 Gy was performed. The acute radiation exposure at a dose rate of 400 mGy/min resulted in the linear dose-dependent increase of the γ-H2AX foci formation. The dose-response curve for the acute exposure was well described by a linear function y = 1.22 + 19.7x, where “y” is an average number of γ-H2AX foci per a cell and “x” is the absorbed dose (Gy. The dose rate reduction down to 10 mGy/min lead to a decreased number of γ-H2AX foci, as well as to a change of the dose-response relationship. Thus, the foci number up to 1.44 Gy increased and reached the “plateau” area between 1.44 and 4.32 Gy. There was only a slight increase of the γ-H2AX foci number (up to 7 in cells after the protracted exposure (up to 72 h to ionizing radiation at a dose rate of 1 mGy/min. Similar effects of the varying dose rates were obtained when DNA damage was assessed using the comet assay. In general, our results show that the reduction of the radiation dose rate resulted in a significant decrease of DSBs per cell per an absorbed dose.

  1. Understanding of altered N-glycosylation-related gene expression in recombinant Chinese hamster ovary cells subjected to elevated ammonium concentration by digital mRNA counting.

    Science.gov (United States)

    Ha, Tae Kwang; Kim, Yeon-Gu; Lee, Gyun Min

    2015-08-01

    To understand the effects of ammonium on N-glycosylation, recombinant Chinese hamster ovary (rCHO) cells that produce the Fc-fusion protein were cultivated in serum-free suspension cultures with 10 mM ammonium addition. The addition of ammonium to the cultures reduced the relative proportion of acidic isoforms and sialic acid content of an Fc-fusion protein. Fifty two N-glycosylation-related gene expressions were assessed by the NanoString nCounter system, which provides a digital readout using custom-designed color-coded probes. Among these queried genes, thirteen genes (gale, nans, gpi, man2a1, b4galt5, b4galt7, st3gal2, st3gal5, glb1, hexa, hexb, neu1, and neu3) were up-regulated over 1.5 times in the culture with ammonium addition after 5 days of culture; however, none of the 54 genes were significantly different after 3 days of culture. In particular, the expression level of neu1 (sialidase-1) and neu3 (sialidase-3), which play a role in reduction of sialylation, increased over 2 times. Likewise, the protein expression levels of sialidase-1 and sialidase-3 determined by Western blot analysis were also increased significantly in the culture with ammonium addition. Transient transfection of neu-1 or neu3-targeted siRNAs significantly improved the sialic acid content of the Fc-fusion protein in the culture with ammonium addition, indicating that the decreased sialic acid content was in part due to the increased expression level of sialidase. Taken together, the results obtained in this study provide a better understanding of the detrimental effect of ammonium on N-glycosylation, especially sialylation, in rCHO cells. PMID:25728222

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

    International Nuclear Information System (INIS)

    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)

  3. 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)

    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

  4. The induction of SCE and chromosomal aberrations with relation to specific base methylation of DNA in Chinese hamster cells by N-methyl-N-nitrosourea and dimethyl sulphate.

    Science.gov (United States)

    Connell, J R; Medcalf, A S

    1982-01-01

    Chinese hamster cells (V79) were treated, either as exponentially proliferating cultures or under conditions where they were density-inhibited, with various doses of the potent carcinogen N-methyl-N-nitrosourea (MNU) or the relatively weak carcinogen dimethylsulphate (DMS). The colony forming ability of these cells and the induced frequencies of sister chromatid exchanges (SCEs) and chromosomal aberrations were assayed. Following the exposure of density-inhibited cells to radio-labelled methylating agents (labelled in the methyl group) these phenomena were related to the levels of 7-methylguanine (7-meGua), O6-methylguanine (O6-meGua) and 3-methyladenine (3-me-Ade) in the DNA. At equitoxic doses MNU and DMS induced similar frequencies of SCEs and chromosomal aberrations. Since, at equitoxic doses, MNU produces approximately 20 times more O6-meGua in V79 cell DNA than does DMS, this indicates that the formation of O6-meGua in DNA is not a major cause of SCEs and chromosomal aberrations. DMS-induced SCEs may be mediated via the production of both 3-meAde and 7-meGua in the DNA; these two methylated purines may also be responsible for MNU-induced SCEs. Therefore, no one specific methylated purine was identified as being solely accountable for the formation of SCEs. Also, the repair of lesions in the DNA of non-replicating V79 cells leads to a reduction in the SCE frequency on their subsequent release from the density-inhibited state, suggesting that repair is not intimately responsible for their formation. No association was discernable between chromosomal aberrations and any of the three methylated purines studied. PMID:7094205

  5. Effect of Temperature Downshift on the Transcriptomic Responses of Chinese Hamster Ovary Cells Using Recombinant Human Tissue Plasminogen Activator Production Culture

    Science.gov (United States)

    Bedoya-López, Andrea; Estrada, Karel; Sanchez-Flores, Alejandro; Ramírez, Octavio T.; Altamirano, Claudia; Segovia, Lorenzo; Miranda-Ríos, Juan; Trujillo-Roldán, Mauricio A.; Valdez-Cruz, Norma A.

    2016-01-01

    Recombinant proteins are widely used as biopharmaceuticals, but their production by mammalian cell culture is expensive. Hence, improvement of bioprocess productivity is greatly needed. A temperature downshift (TDS) from 37°C to 28–34°C is an effective strategy to expand the productive life period of cells and increase their productivity (qp). Here, TDS in Chinese hamster ovary (CHO) cell cultures, initially grown at 37°C and switched to 30°C during the exponential growth phase, resulted in a 1.6-fold increase in the qp of recombinant human tissue plasminogen activator (rh-tPA). The transcriptomic response using next-generation sequencing (NGS) was assessed to characterize the cellular behavior associated with TDS. A total of 416 (q > 0.8) and 3,472 (q > 0.9) differentially expressed transcripts, with more than a 1.6-fold change at 24 and 48 h post TDS, respectively, were observed in cultures with TDS compared to those at constant 37°C. In agreement with the extended cell survival resulting from TDS, transcripts related to cell growth arrest that controlled cell proliferation without the activation of the DNA damage response, were differentially expressed. Most upregulated genes were related to energy metabolism in mitochondria, mitochondrial biogenesis, central metabolism, and avoidance of apoptotic cell death. The gene coding for rh-tPA was not differentially expressed, but fluctuations were detected in the transcripts encoding proteins involved in the secretory machinery, particularly in glycosylation. Through NGS the dynamic processes caused by TDS were assessed in this biological system. PMID:26991106

  6. A comparison of cell killing by heat and/or x rays in Chinese hamster V79 cells, Friend erythroleukemia mouse cells, and human thymocyte MOLT-4 cells

    International Nuclear Information System (INIS)

    The radiation and/or heat sensitivity of Chinese hamster V79 cells, Friend erythroleukemia (FELC) mouse cells, and MOLT-4 human transformed thymocytes were compared. MOLT-4 cells were more radiosensitive (D/sub o/=0.50 Gy) than FELC (D/sub o/ = 0.65 Gy) and V79 cells (D/sub o/ = 1.43 Gy). Arrhenius analysis showed that MOLT-4 cells were more heat sensitive than FELC or V79 cells below 42.00C, but more heat resistant at higher temperatures. In addition, the MOLT-4 cells showed a single-heat inactivation energy between 41.0 and 45.00C, while FELC and V79 cells both showed a transition in the inactivation energy at about 43.0 and 43.50C, respectively. These differences may be related to the fact that the upper temperature limit for the development of thermal tolerance during continuous heating was lower for MOLT-4 cells than for FELC or V79 cells. Killing of FELC and V79 cells was dependent on the sequence in which heat and X rays were applied, but the greatest effect was obtained when both treatments were given simultaneously. Recovery occurred when treatments were separated by incubation at 37.00C. The MOLT-4 cells did not show a sequence dependence for heating and irradiation. Survival of MOLT-4 cells after heating and/or irradiation was compared using trypan blue dye exclusion or colony formation. Both assays showed similar qualitative responses, but survival levels measured by the trypan blue assay were much higher than those determined from the colony-forming assay

  7. 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.

  8. 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)

    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 [14C]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, [14C]serine uptake was not blocked, total lipid biosynthesis from [14C]acetic acid was not decreased (nor was the appearance of radiolabel in cholesterol and phosphatidylcholine), and [3H]thymidine incorporation into DNA was not affected. There appeared to be little effect on protein synthesis based on the incorporation of [3H]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

  9. 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.

  10. 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)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-09-06

    The effects of ..beta..-chloroalanine (..beta..-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 ..beta..-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 ..beta..-Cl-alanine and this treatment inhibited (/sup 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 ..beta..-Cl-alanine appeared to occur with little perturbation of other cell functions: the cells exhibited no loss in cell viability, (/sup 14/C)serine uptake was not blocked, total lipid biosynthesis from (/sup 14/C)acetic acid was not decreased (nor was the appearance of radiolabel in cholesterol and phosphatidylcholine), and (/sup 3/H)thymidine incorporation into DNA was not affected. There appeared to be little effect on protein synthesis based on the incorporation of (/sup 3/H)leucine, which was only decreased by 14%. Although ..beta..-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 ..beta..-Cl-alanine and other mechanism-based inhibitors might be useful to study alterations in cellular long-chain base synthesis.

  12. Purification and characterization of chimeric human IgA1 and IgA2 expressed in COS and Chinese hamster ovary cells.

    Science.gov (United States)

    Morton, H C; Atkin, J D; Owens, R J; Woof, J M

    1993-11-01

    Ag-specific chimeric human IgA molecules, of the two human subclasses, IgA1 and IgA2, have been expressed in two mammalian cell systems. Analysis of the secreted IgA molecules, purified in milligram quantities from stable Chinese hamster ovary transfectants by Ag affinity chromatography, has allowed a direct comparison of the biologic properties of the two subclasses. HPLC gel filtration analysis revealed that in both subclasses, the IgA molecules associate predominantly into dimers. The monomer units are presumed to interact noncovalently, inasmuch as no dimers are evident when the antibodies are subjected to SDS-PAGE. The recombinant antibodies are glycosylated, inasmuch as a lectin blotting procedure revealed that the H chains of both subclasses are recognized by Con A. When subjected to digestion by preparations of IgA1-specific proteases secreted by two pathogenic streptococcal strains, Streptococcus sanguis and Streptococcus oralis, the recombinant IgA molecules behave just as their natural equivalents. Thus, only the chimeric IgA1 molecule is cleaved, with the IgA2 remaining intact. In terms of interaction with natural effector molecules, both recombinant IgA isotypes were shown to interact with Fc alpha receptors on calcitriol-stimulated HL-60 cells with similar affinity, but neither antibody was found to interact with human C1q. The expression system described readily permits manipulation of the human IgA genes, which should lead to a fuller molecular understanding of how this important antibody mediates its function. PMID:8409433

  13. Comparison of the functional potencies of ropinirole and other dopamine receptor agonists at human D2(long), D3 and D4.4 receptors expressed in Chinese hamster ovary cells

    OpenAIRE

    Coldwell, Martyn C; Boyfield, Izzy; Brown, Tony; Hagan, Jim J.; Middlemiss, Derek N

    1999-01-01

    The aim of the present study was to characterize functional responses to ropinirole, its major metabolites in man (SKF-104557 (4-[2-(propylamino)ethyl]-2-(3H) indolone), SKF-97930 (4-carboxy-2-(3H) indolone)) and other dopamine receptor agonists at human dopamine D2(long) (hD2), D3 (hD3) and D4.4 (hD4) receptors separately expressed in Chinese hamster ovary cells using microphysiometry.All the receptor agonists tested (ropinirole, SKF-104557, SKF-97930, bromocriptine, lisuride, pergolide, pra...

  14. Bioprocess development for the production of mouse-human chimeric anti-epidermal growth factor receptor vIII antibody C12 by suspension culture of recombinant Chinese hamster ovary cells

    OpenAIRE

    Hu, Suwen; Deng, Lei; Wang, Huamao; Zhuang, Yingping; Chu, Ju; Zhang, Siliang; Li, Zhonghai; Guo, Meijin

    2011-01-01

    The mouse-human chimeric anti-epidermal growth factor receptor vIII (EGFRvIII) antibody C12 is a promising candidate for the diagnosis of hepatocellular carcinoma (HCC). In this study, 3 processes were successfully developed to produce C12 by cultivation of recombinant Chinese hamster ovary (CHO-DG44) cells in serum-free medium. The effect of inoculum density was evaluated in batch cultures of shaker flasks to obtain the optimal inoculum density of 5 × 105 cells/mL. Then, the basic metabolic ...

  15. Evidence for cross-talk between M2 and M3 muscarinic acetylcholine receptors in the regulation of second messenger and extracellular signal-regulated kinase signalling pathways in Chinese hamster ovary cells

    OpenAIRE

    Hornigold, David C; Mistry, Rajendra; Raymond, Pamela D; Blank, Jonathan L; John Challiss, R A

    2003-01-01

    We have examined possible mechanisms of cross-talk between the Gq/11-linked M3 muscarinic acetylcholine (mACh) receptor and the Gi/o-linked M2 mACh receptor by stable receptor coexpression in Chinese hamster ovary (CHO) cells. A number of second messenger (cyclic AMP, Ins(1,4,5)P3) and mitogen-activated protein kinase (ERK and JNK) responses stimulated by the mACh receptor agonist methacholine were examined in CHO-m2m3 cells and compared to those stimulated in CHO-m2 and CHO-m3 cell-lines, ex...

  16. Optional exon in the 5'-untranslated region of 3-hydroxy-3-methylglutaryl coenzyme A synthase gene: conserved sequence and splicing pattern in humans and hamsters

    International Nuclear Information System (INIS)

    3-Hydroxy-3-methylglutaryl coenzyme A synthase (hydroxymethylglutaryl-CoA synthase, EC 4.1.3.5) is a negatively regulated enzyme in the synthetic pathway for cholesterol, isopentenyl tRNA, and other isoprenoids. The 5'-untranslated region of the mRNA for Chinese hamster hydroxymethylglutaryl-CoA synthase contains an optional exon of 59 nucleotides located 10 nucleotides upstream of the translation start site. About 50% of the mRNAs contain this exon, and the other 50% lack it owing to differential intron splicing. The authors show that the two transcripts are found in similar ratios in multiple tissues of the Syrian hamster, including the brain. The relative amounts of the two transcripts in brain and liver are constant from day 0 to day 75 of life. A similar alternative splicing pattern for hydroxymethylglutaryl-CoA synthase was observed in three human tissues: cultured fibroblasts, fetal adrenal gland, and fetal liver. A cDNA for human synthase had 90% homology to the hamster sequence in the region corresponding to the optional exon. This sequence contains a 20 out of 26 nucleotide match with the sequence immediately upstream of the initiator AUG codon in the mRNA for hamster hydroxymethylglutaryl-CoA reductase, the enzyme that follows the synthase in the isoprenoid biosynthetic pathway. These findings raise the possibility that the optional exon plays an important, conserved functional role in humans and hamsters

  17. Fibroblast growth factor receptor 4 Gly388Arg polymorphism in Chinese gastric cancer patients

    Directory of Open Access Journals (Sweden)

    Yan-Ying Shen

    2013-01-01

    Full Text Available AIM: To investigate the contribution of the fibroblast growth factor receptor 4 (FGFR4 Gly388Arg polymorphism as a genetic risk factor for gastric cancer (GC and to investigate any associations between this polymorphism and clinicopathological parameters and survival. METHODS: Tumors and matched adjacent non-cancer tissues were collected from 304 GC patients, and 5 mL of venous blood was collected from 62 GC patients and 392 age- and sex-matched healthy controls without cancer history from the same ethnic population. DNA was extracted, and direct sequencing analyses were performed to genotype the FGFR4 Gly388Arg polymorphism in all the samples. Differences in the genotype frequencies of the FGFR4 Gly388Arg polymorphism between GC patients and healthy controls were estimated using the χ2 test. Binary logistic regression was used for all analysis variables to estimate risk as the ORs with 95%CIs. The relationships between the FGFR4 genotype and clinicopathological parameters were tested with the χ2 test. The Kaplan-Meier product-limit method, the log-rank test, and the Cox regression model were applied to evaluate the effect of the FGFR4 genotype on the overall survival of patients with GC. RESULTS: In the present GC cohort, 118 patients (38.8% were homozygous for the Gly388 allele, 124 patients (40.8% were heterozygous, and 62 patients (20.4% were homozygous for the Arg388 allele. The frequencies of the Gly/Gly, Gly/Arg, and Arg/Arg genotypes in the healthy controls were 33.6%, 48.0%, and 18.4%, respectively. The distributions of genotypes (χ2 = 3.589, P = 0.166 and alleles (χ2 = 0.342, P = 0.559 of the FGFR4 Gly388Arg polymorphism were not different between the GC patients and the healthy controls. Although we observed no correlation between the FGFR4 Gly388Arg polymorphism and clinicopathological parameters or survival in the total cohort of GC patients, the presence of the Arg388 allele was associated with shorter survival time in patients

  18. Stimulation of 125I-3-iodo-α-methyl-L-tyrosine uptake in Chinese hamster ovary (CHO-K1) cells by tyrosine esters

    International Nuclear Information System (INIS)

    Introduction: Transport of the amino acid analog 123I-3-iodo-α-methyl-L-tyrosine, which is used in clinical SPECT imaging, occurs mainly via L-type amino acid transporter type 1 (LAT1; an amino acid exchanger). As LAT1 is highly expressed in actively proliferating tumors, we made a preliminary investigation of the effects of amino acid esters on enhancement of 125I-3-iodo-α-methyl-L-tyrosine (IMT) uptake via LAT1 in Chinese hamster ovary (CHO-K1) cells. Methods: Because the sequence of the CHO-K1 LAT1 gene is not available, we confirmed LAT1 expression through IMT (18.5 kBq) uptake mechanisms using specific inhibitors. L-Gly, L-Ser, L-Leu, L-Phe, L-Met, L-Tyr, D-Tyr, L-Val and L-Lys ethyl/methyl esters were tested in combination with IMT. Time-course studies over a 3-h period were conducted, and the concentration dependence of L-Tyr ethyl and methyl esters (0.001 to 10 mM) in combination with IMT was also examined. For a proof of de-esterification of L- and D-Tyr ethyl and methyl esters in the cells (by enzymatic attack or other cause), the concentration of L- and D-Tyr was analyzed by high-performance liquid chromatography of the esters in phosphate buffer (pH 7.4) and cell homogenates at 37 deg. C or under ice-cold conditions. Results: Inhibition tests suggested that LAT1 is involved in IMT uptake by CHO-K1 cells. Co-administration of 1 mM of L-Tyr ethyl or methyl ester with IMT produced the greatest enhancement. The de-esterification reaction was stereo selective and temperature dependent in the homogenate. De-esterification kinetics were very fast in the homogenate and very slow in the phosphate buffer. Conclusions: The L-Tyr ethyl or methyl esters were the most effective enhancers of IMT uptake into CHO-K1 cells and acted by trans-stimulation of the amino acid exchange function of LAT1. This result suggests that de-esterification in the cells may be caused by enzymatic attack. We will use IMT and L-Tyr ethyl or methyl esters to examine LAT1 function in tumor

  19. PARP inhibitor 3-aminobenzamide does not increase the yields of chromosomal aberrant cells induced by boron neutron capture reaction in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Full text: Mechanistic knowledge on DNA and cell damage induced by alpha-particles remains limited. It is well known that high-LET radiation induces both DNA single (ssb) and double strand breaks (dsb), being the latter frequently associated with cell death. The repair of these DNA lesions and specially dsb are thus fundamental for the understanding of high-LET radiation effects. Poly (ADP-ribose) polymerase is a nuclear enzyme, which detects and signals DNA strand breaks (ssb and dsb). The important role of this enzyme in the maintenance of DNA integrity has been extensively studied for genotoxic chemicals and low-LET ionizing radiation. Nevertheless, sparse information concerning the role of PARP in high-LET radiation effects is available. The purpose of this work is to examine whether the PARP inhibitor 3-aminobenzamide (3-AB) enhances the yields of chromosomal aberrations induced by the boron neutron capture (BNC) reaction in V79 Chinese hamster cells. Wild-type V79 cells were pre-incubated for 48 hours with different concentrations (0.48-2.4 mM) of the boron delivery agent 4-borono-L-phenylalanine (BPA) and then irradiated for different periods of time with thermal neutrons. In the 3-AB treated cultures, four hours before the irradiation the cells were incubated with different concentrations of this inhibitor (1.5-10 mM) which remained in culture until colchicine was added. The chromosomal aberrations assay was performed according to standard protocol. A clear dose-response in the frequencies of chromosomal aberrant cells excluding gaps (%CAEG) induced by the BNC reaction was observed for both BPA concentration and thermal neutron fluence. There was no evidence of an increase in the % CAEG induced after incubation with 3-AB. Some cytoxicity was observed (mitotic index) after 3-AB incubation in BPA irradiated cells. In conclusion, the clastogenic potential of the alpha-particles generated through the BNC reaction was not affected by using a classic PARP

  20. Defects of tyrosine289phenylalanine mutation on binding and functional properties of the human tachykinin NK2 receptor stably expressed in chinese hamster ovary cells.

    Science.gov (United States)

    Renzetti, A R; Catalioto, R M; Carloni, C; Criscuoli, M; Cucchi, P; Giolitti, A; Zappitelli, S; Rotondaro, L; Maggi, C A

    1999-04-15

    A point mutation was made at position 289 in the transmembrane segment 7 of the human tachykinin NK2 receptor to yield a tyrosine/phenylalanine (Tyr/Phe) substitution. Chinese hamster ovary cells stably transfected with the wild-type or Tyr289Phe mutant NK2 receptor both bound neurokinin A (NKA) and the synthetic NK2 receptor-selective agonists, GR 64349 and [betaAla8]NKA(4-10), with high and even affinities. Neurokinin B (NKB) and substance P (SP) also displayed sizeable binding affinities, albeit with lower affinity as compared to NKA. In a functional assay (production of inositol-1,4,5-trisphosphate, IP3), NKA, GR 64349, and [betaAla8]INKA(4-10) stimulated IP3 accumulation via the wild-type and mutant receptors with similar potencies. On the other hand, NKB and SP exhibited a dramatic reduction in their agonist efficacies at the mutant receptor, NKB acting as a partial agonist (maximum effect = 50% of the response to NKA) and SP being totally inactive. The results obtained with phenoxybenzamine inactivation experiments indicated that a large and similar receptor reserve existed for both the wild-type and the mutant receptor. SP, which displayed sizeable binding affinity for the mutant receptor but did not stimulate IP3 accumulation, antagonized the agonist effect of NKA. The antagonist action of SP at the mutant NK2 receptor cannot be ascribed to receptor internalization. The Tyr/Phe replacement at position 289 markedly reduced the binding affinity and antagonist potency of the non-peptide ligand, SR 48968, without affecting the binding affinity and antagonist potency of the bicyclic peptide antagonist MEN 11420. The results indicate that the hydroxyl radical function of Tyr289 in transmembrane segment 7 of the human NK2 receptor is, directly or indirectly, involved in stimulus transduction when the NK2 receptor is occupied by NKB or SP, but not when using NKA or NK2 receptor-selective agonists. PMID:10086323

  1. 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)

    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 60Co 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

  2. 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.

  3. Human chromosome 5 complements the DNA double-strand break-repair deficiency and gamma-ray sensitivity of the XR-1 hamster variant.

    OpenAIRE

    Giaccia, A. J.; Denko, N; MAcLAREN, R.; Mirman, D; Waldren, C; Hart, I; Stamato, T D

    1990-01-01

    XR-1 is a Chinese hamster ovary (CHO) cell mutant which is unusually sensitive to killing by gamma rays in the G1 portion of the cell cycle but has nearly normal resistance to gamma-ray damage in late S phase. The cell-cycle sensitivity correlates with the mutant's inability to repair DNA double-strand breaks (DSBs) produced by ionizing radiation and restriction enzymes. We have previously shown in somatic cell hybrids of XR-1 cells and human fibroblasts that the XR-1 mutation is a recessive ...

  4. Overleeft de hamster?

    NARCIS (Netherlands)

    Apeldoorn, van R.C.; Klein Douwel, C.; Thomas, P.

    1999-01-01

    Een analyse van de achteruitgang van de hamster (Cricetus cricetus) in Europa en Limburg, de oorzaken (veranderingen in de landbouw; versnippering van leefgebieden), en oplossingsrichtingen voor een duurzaam overleven van de hamster in Limburg (kernpopulaties in duurzame populatienetwerken)

  5. Uptake of inorganic and organic derivatives of arsenic associated with induced cytotoxic and genotoxic effects in Chinese hamster ovary (CHO) cells

    International Nuclear Information System (INIS)

    Humans are exposed to arsenic and their organic derivatives, which are widely distributed in the environment, via food, water, and to a lesser extent, via air. Following uptake, inorganic arsenic undergoes biotransformation to mono- and dimethylated metabolites. Recent findings suggest that the methylation reactions represent a toxification rather than a detoxification pathway. In the present study, the genotoxic effects and the cellular uptake of inorganic arsenic [arsenate, Asi(V); arsenite, Asi(III)] and the methylated arsenic species monomethylarsonic acid [[MMA(V)], monomethylarsonous acid [MMA(III)], dimethylarsinic acid [DMA(V)], dimethylarsinous acid [DMA(III)], trimethylarsenic oxide [TMAO(V)] were investigated in Chinese hamster ovary (CHO-9) cells. The chemicals were applied at different concentrations (0.1 μM to 10 mM) for 30 min and 1 h, respectively. Cytotoxic effects were investigated by the trypan blue extrusion test and genotoxic effects by the assessment of micronucleus (MN) induction, chromosome aberrations (CA), and sister chromatid exchanges (SCE). Intracellular arsenic concentrations were determined by ICP-MS techniques. Our results show that MMA(III) and DMA(III) induce cytotoxic and genotoxic effects to a greater extent than MMA(V) or DMA(V). Viability was significantly decreased after incubation (1 h) of the cells with ≥ 1 μM Asi(III), ≥ 1 μM Asi(V), ≥ 500 μM MMA(III), ≥ 100 μM MMA(V), and 500 μM DMA(V) and ≥ 0.1 μM DMA(III). TMAO(V) was not cytotoxic at concentrations up to 10 mM. A significant increase of the number of MN, CA and SCE was found for DMA(III) and MMA(III). Asi(III + V) induced CA and SCE but no MN. TMAO(V), MMA(V) and DMA(V) were not genotoxic in the concentration range tested (up to 5 mM). The nuclear division index (NDI) was not affected by any of the tested arsenic compounds after a recovery period of 14 to 35 h. When the uptake of the chemicals was measured by ICP-MS analysis, it was found that only 0

  6. Comparative effect of the thiols dithiothreitol, cysteamine and WR-151326 on survival and on the induction of DNA damage in cultured Chinese hamster ovary cells exposed to γ-radiation

    International Nuclear Information System (INIS)

    The authors compared the ability of dithiothreitol (DTT) cysteamine and WR-151326 to protect aerated Chinese hamster ovary cells from lethal and DNA-damaging effects of γ-radiation. Results were compared with earlier measurements for WR-1065 and WR-255591. All three thiols protected against SS6 induction, though to a significantly lower extent than against cell killing measured under identical conditions. Each thiol also protected against dsb induction. After high radiation doses, protection factors for dsb were also less than protection factors for cell survival; however, the relative effect of each thiol on cell survival and on dsb induction appeared to be equivalent. The hierarchy of protection against both SS6 and dsb was similar to that for cell survival i.e. WR 151326 ≅ cysteamine < DDT. (UK)

  7. 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.

  8. EFFECTS OF PHORBOL MYRISTATE ACETATE, PHORBOL DIBUTYRATE, ETHANOL, DIMETHYLSULFOXIDE, PHENOL, AND SEVEN METABOLITIES OF PHENOL ON METABOLIC COOPERATION BETWEEN CHINESE HAMSTER V79 LUNG FIBROBLASTS

    Science.gov (United States)

    The discovery that phorbol ester tumor promoters inhibit metabolic cooperation (MC) between several cell types in vitro fostered the idea that the effect might be associated with tumor promoters in general. The authors are testing the hypothesis by assessing the effects of tumor ...

  9. Fluoride does not induce DNA breakage in Chinese hamster ovary cells in vitro Flúor não induz danos ao DNA em células de ovário de hamster chinês in vitro

    Directory of Open Access Journals (Sweden)

    Daniel Araki Ribeiro

    2004-09-01

    Full Text Available Fluoride has been widely used in dentistry because it is a specific and effective caries prophylactic agent. However, excess fluoride may represent a hazard to human health, especially by causing injury to genetic material. Genotoxicity tests represent an important part of cancer research to assess the risk of potential carcinogens. In the current study, the potential DNA damage associated with exposure to fluoride was assessed by the single cell gel (comet assay in vitro. Chinese hamster ovary cells were exposed to sodium fluoride (NaF at final concentration ranging from 7 to 100 µg/ml for 3 h, at 37°C. The results pointed out that NaF in all concentrations tested did not contribute to DNA damage as depicted by the mean tail moment and tail intensity. These findings are clinically important since they represent an important contribution to a correct evaluation of the potential health risk associated with the exposure to dental agents.O flúor tem sido amplamente usado na Odontologia, pois é um agente profilático efetivo e específico contra a cárie dentária. Entretanto, o flúor em excesso pode representar perigos à saúde humana, especialmente por causar agressão ao material genético. Testes de genotoxicidade representam uma importante parte da pesquisa do câncer para a avaliação de risco de possíveis carcinógenos. Neste presente estudo, danos ao DNA associados à exposição ao flúor foram avaliados pelo teste de células individualizadas em gel de agarose (teste do cometa in vitro. Células de ovário de hamster chinês foram expostas ao fluoreto de sódio (NaF nas concentrações finais de 7 a 100 µg/ml, durante 3 h, a 37°C. Os resultados mostraram que o NaF não contribuiu para os danos no DNA em todas as concentrações testadas, conforme demonstrado pelas médias do momento da cauda e da intensidade da cauda dos cometas. Esses achados são clinicamente importantes, uma vez que representam uma importante contribui

  10. 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.

  11. The effect of repeated small doses of radiation on recovery from sublethal damage by Chinese hamster cells irradiated in oxic or hypoxic conditions in the plateau phase of growth

    International Nuclear Information System (INIS)

    Unfed plateau phase Chinese hamster cells have been irradiated with either single doses or up to ten fractions of x-rays six hours apart. These cells remained in an extended G1-like phase throughout the irradiation period. The single-dose log survival curve had an extrapolation number of about 9 and the oxygen enhancement ratio was three. Cells were exposed either to 200 rad per fraction in air and 600 rad per fraction in hypoxia (during irradiation only), or 150 rad per fraction in air and 450 rad per fraction in hypoxia. The resulting fractionated log survival curves did not fit a multitarget model of cell survival, being much steeper than that would predict. The addition of a single-hit component to the lethal effect of the radiation gave reasonable agreement for the first five fractions although the curves tended to bend downwards with increasing number of fractions. The log survival curve for cells irradiated with five fractions of 200 rad (or 600 rad in hypoxia) six hours apart and graded doses six hours after the fifth fraction had an extrapolation number much less than that following single doses, implying a decreased ability to absorb radiation damage as sublethal. The ratio of the initial slopes of the fractionated log survival curves for irradiation in air and hypoxia was less than three, implying that the oxygen enhancement ratio on the shoulder may be less than that in the exponential region of survival. (author)

  12. Inhibition of X-ray-induced potentially lethal damage (PLD) repair by cordycepin (3'-deoxyadenosine) and enhancement of its action by 2'-deoxycoformycin in Chinese Hamster hai cells in the stationary phase in Vitro

    International Nuclear Information System (INIS)

    The effects of growth phase and chemicals on PLD repair were studied in X-irradiated Chinese hamster hai cells. The change in capacity of cells in different growth phases to repair PLD was investigated. Starting from cells in the log phase, the magnitude of PLD repair during 10 hr of postirradiation incubation in Hanks' balanced salt solution increased for 2.5 to 18 as the cultures approached the stationary phase, which occurred on the 7th or 8th day. The effects of chemicals dissolved in Hanks' BSS on PLD repair were studied using 10th- or 12th-day cultures. Among the chemicals tested, caffeine and cordycepin were effective in inhibiting PLD repair. When 2'-deoxycoformycin, an inhibitor of adenosine deaminase, was combined with cordycepin, the effect of cordycepin was enhanced. Due to this prevention of the deamination of cordycepin by 2'-deoxycoformycin, the inhibition of PLD repair was prolonged, indicating a possible clinical application of cordycepin as a radiosensitizer

  13. 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

    International Nuclear Information System (INIS)

    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

  14. THINDOWN IN RADIOBIOLOGY:E.COLI B/r,Bs—1,B.SUBTILUS SPORES,AND V—79 CHINESE HAMSTER CELLS

    Institute of Scientific and Technical Information of China (English)

    张纯祥; RobertKatz

    1995-01-01

    Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology,Here,a new calculation of the radial distribution of dose is applied,in which the classical angular distribtuion of dose of delta rays and a logarithmic polynomial representation of the electron range-energy relation are used.to form the basis of the present thindown calculation.Calculations of inactivation cross sections for heavy ions in the track width regime displaying thindown for E.Coli B/r and Bs-1,and for Bacillus Subtilus are straightforward for these are 1-hit detectors.Calculations for V-79 hamster cells are more complex.They follow the orginal development of this model for eucaryotic cells,and make use of the cross sections calculated for hypothetical internal targets which are then asserted to be proportional to the measured ceelular inactivation cross sections.The results are in reasonable agreement with experimental ,data.

  15. Comparison of repair of DNA double-strand breaks in identical sequences in primary human fibroblast and immortal hamster-human hybrid cells harboring a single copy of human chromosome 11

    Science.gov (United States)

    Fouladi, B.; Waldren, C. A.; Rydberg, B.; Cooper, P. K.; Chatterjee, A. (Principal Investigator)

    2000-01-01

    We have optimized a pulsed-field gel electrophoresis assay that measures induction and repair of double-strand breaks (DSBs) in specific regions of the genome (Lobrich et al., Proc. Natl. Acad. Sci. USA 92, 12050-12054, 1995). The increased sensitivity resulting from these improvements makes it possible to analyze the size distribution of broken DNA molecules immediately after the introduction of DSBs and after repair incubation. This analysis shows that the distribution of broken DNA pieces after exposure to sparsely ionizing radiation is consistent with the distribution expected from randomly induced DSBs. It is apparent from the distribution of rejoined DNA pieces after repair incubation that DNA ends continue to rejoin between 3 and 24 h postirradiation and that some of these rejoining events are in fact misrejoining events, since novel restriction fragments both larger and smaller than the original fragment are generated after repair. This improved assay was also used to study the kinetics of DSB rejoining and the extent of misrejoining in identical DNA sequences in human GM38 cells and human-hamster hybrid A(L) cells containing a single human chromosome 11. Despite the numerous differences between these cells, which include species and tissue of origin, levels of TP53, expression of telomerase, and the presence or absence of a homologous chromosome for the restriction fragments examined, the kinetics of rejoining of radiation-induced DSBs and the extent of misrejoining were similar in the two cell lines when studied in the G(1) phase of the cell cycle. Furthermore, DSBs were removed from the single-copy human chromosome in the hamster A(L) cells with similar kinetics and misrejoining frequency as at a locus on this hybrid's CHO chromosomes.

  16. 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

  17. Poly(N-isopropylacrylamide)-coated thermo-responsive nanoparticles for controlled delivery of sulfonated Zn-phthalocyanine in Chinese hamster ovary cells in vitro and zebra fish in vivo

    Science.gov (United States)

    He, Jia; Chen, Ji-Yao; Wang, Pu; Wang, Pei-Nan; Guo, Jia; Yang, Wu-Li; Wang, Chang-Chun; Peng, Qian

    2007-10-01

    Poly(N-isopropylacrylamide) (PNIPAM)-coated Fe3O4@SiO2@CdTe multifunctional nanoparticles with photoluminescent (PL), thermosensitive and magnetic properties, were investigated as carriers to deliver water-soluble, fluorescent sulfonated Zn-phthalocyanine (ZnPcS), a photosensitizing drug for photodynamic therapy of cancer, in Chinese hamster ovary (CHO) cells in vitro and zebra fish in vivo. PNIPAM is a well-known thermo-responsive polymer with a volume phase transition temperature. This property allows it to be swollen in water at temperatures lower than 32-34 °C to take up ZnPcS and shrunken to expel the drug at higher temperatures. Since the PL band of CdTe quantum dots (QDs) as indicators for the nanoparticles is at 585 nm and the emission band of ZnPcS is at 680 nm, it is possible to study the temperature-dependent release of ZnPcS from the nanoparticles by fluorescence measurements. ZnPcS was embedded in the PNIPAM of the nanoparticles at 25 °C in phosphate buffered saline (PBS) solution and released at 37 °C, measured with a spectrophotometer. When CHO cells had been incubated with the ZnPcS-loaded nanoparticles at 27 °C, a similar intracellular localization pattern of CdTe QDs and ZnPcS was seen by multichannel measurements in confocal laser scanning microscopy (CLSM), but a diffuse pattern of only ZnPcS fluorescence was detected in the cytoplasm of the cells at 37 °C, indicating a release of ZnPcS from the nanoparticles. Similar results were also found in the intestinal tract of zebra fish in vivo after intake of the nanoparticles. Since the nanoparticles contain magnetic (Fe3O4) material, the nanoparticles could also be manipulated to change their location in the intestinal tract of the zebra fish with an external magnetic field gradient of 300 G mm-1. The results presented suggest that such multifunctional nanoparticles may have combined potential for temperature-dependent drug delivery, QD photodetection and magnetic manipulation in diagnosis and

  18. Poly(N-isopropylacrylamide)-coated thermo-responsive nanoparticles for controlled delivery of sulfonated Zn-phthalocyanine in Chinese hamster ovary cells in vitro and zebra fish in vivo

    Energy Technology Data Exchange (ETDEWEB)

    He Jia [Surface Physics Laboratory (National Key Laboratory) and Department of Physics, Fudan University, Shanghai (China); Chen Jiyao [Surface Physics Laboratory (National Key Laboratory) and Department of Physics, Fudan University, Shanghai (China); Wang Pu [Surface Physics Laboratory (National Key Laboratory) and Department of Physics, Fudan University, Shanghai (China); Wang Peinan [State Key Laboratory for Advanced Photonic Materials and Devices, Fudan University, Shanghai (China); Guo Jia [Department of Macromolecular Science and Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai (China); Yang Wuli [Department of Macromolecular Science and Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai (China); Wang Changchun [Department of Macromolecular Science and Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai (China); Peng Qian [State Key Laboratory for Advanced Photonic Materials and Devices, Fudan University, Shanghai (China)

    2007-10-17

    Poly(N-isopropylacrylamide) (PNIPAM)-coated Fe{sub 3}O{sub 4} - SiO{sub 2} - CdTe multifunctional nanoparticles with photoluminescent (PL), thermosensitive and magnetic properties, were investigated as carriers to deliver water-soluble, fluorescent sulfonated Zn-phthalocyanine (ZnPcS), a photosensitizing drug for photodynamic therapy of cancer, in Chinese hamster ovary (CHO) cells in vitro and zebra fish in vivo. PNIPAM is a well-known thermo-responsive polymer with a volume phase transition temperature. This property allows it to be swollen in water at temperatures lower than 32-34 deg. C to take up ZnPcS and shrunken to expel the drug at higher temperatures. Since the PL band of CdTe quantum dots (QDs) as indicators for the nanoparticles is at 585 nm and the emission band of ZnPcS is at 680 nm, it is possible to study the temperature-dependent release of ZnPcS from the nanoparticles by fluorescence measurements. ZnPcS was embedded in the PNIPAM of the nanoparticles at 25 deg. C in phosphate buffered saline (PBS) solution and released at 37 deg. C, measured with a spectrophotometer. When CHO cells had been incubated with the ZnPcS-loaded nanoparticles at 27 deg. C, a similar intracellular localization pattern of CdTe QDs and ZnPcS was seen by multichannel measurements in confocal laser scanning microscopy (CLSM), but a diffuse pattern of only ZnPcS fluorescence was detected in the cytoplasm of the cells at 37 deg. C, indicating a release of ZnPcS from the nanoparticles. Similar results were also found in the intestinal tract of zebra fish in vivo after intake of the nanoparticles. Since the nanoparticles contain magnetic (Fe{sub 3}O{sub 4}) material, the nanoparticles could also be manipulated to change their location in the intestinal tract of the zebra fish with an external magnetic field gradient of 300 G mm{sup -1}. The results presented suggest that such multifunctional nanoparticles may have combined potential for temperature-dependent drug delivery, QD

  19. Poly(N-isopropylacrylamide)-coated thermo-responsive nanoparticles for controlled delivery of sulfonated Zn-phthalocyanine in Chinese hamster ovary cells in vitro and zebra fish in vivo

    International Nuclear Information System (INIS)

    Poly(N-isopropylacrylamide) (PNIPAM)-coated Fe3O4 - SiO2 - CdTe multifunctional nanoparticles with photoluminescent (PL), thermosensitive and magnetic properties, were investigated as carriers to deliver water-soluble, fluorescent sulfonated Zn-phthalocyanine (ZnPcS), a photosensitizing drug for photodynamic therapy of cancer, in Chinese hamster ovary (CHO) cells in vitro and zebra fish in vivo. PNIPAM is a well-known thermo-responsive polymer with a volume phase transition temperature. This property allows it to be swollen in water at temperatures lower than 32-34 deg. C to take up ZnPcS and shrunken to expel the drug at higher temperatures. Since the PL band of CdTe quantum dots (QDs) as indicators for the nanoparticles is at 585 nm and the emission band of ZnPcS is at 680 nm, it is possible to study the temperature-dependent release of ZnPcS from the nanoparticles by fluorescence measurements. ZnPcS was embedded in the PNIPAM of the nanoparticles at 25 deg. C in phosphate buffered saline (PBS) solution and released at 37 deg. C, measured with a spectrophotometer. When CHO cells had been incubated with the ZnPcS-loaded nanoparticles at 27 deg. C, a similar intracellular localization pattern of CdTe QDs and ZnPcS was seen by multichannel measurements in confocal laser scanning microscopy (CLSM), but a diffuse pattern of only ZnPcS fluorescence was detected in the cytoplasm of the cells at 37 deg. C, indicating a release of ZnPcS from the nanoparticles. Similar results were also found in the intestinal tract of zebra fish in vivo after intake of the nanoparticles. Since the nanoparticles contain magnetic (Fe3O4) material, the nanoparticles could also be manipulated to change their location in the intestinal tract of the zebra fish with an external magnetic field gradient of 300 G mm-1. The results presented suggest that such multifunctional nanoparticles may have combined potential for temperature-dependent drug delivery, QD photodetection and magnetic manipulation

  20. Radioiodinated 4-iodo-L-meta-tyrosine, a system L selective artificial amino acid: molecular design and transport characterization in Chinese hamster ovary cells (CHO-K1 cells)

    International Nuclear Information System (INIS)

    Introduction: High expression of the system L amino acid transporter has been observed in clinically important tissues including tumors and the blood-brain barrier. We examined amino acid transport system L selectivity of 14C(U)-L-tyrosine (14C-Tyr), 125I-4-iodo-L-meta-tyrosine (4-125I-mTyr), 125I-6-iodo-L-meta-tyrosine (6-125I-mTyr), 125I-3-iodo-α-methyl-L-tyrosine (125I-IMT) and 125I-3-iodo-L-tyrosine (3-125I-Tyr) using Chinese hamster ovary cells (CHO-K1). Methods: Cells in the exponential growth phase were incubated with 18.5 kBq of labeled amino acid in 2 mL of phosphate-buffered saline-based uptake solution and an uptake solution with/without Na+ at 37oC or 4oC. We examined the 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); 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (a specific inhibitor of system L, in Na+-free uptake solution); sodium azide and 2,4-dinitrophenol (NaN3 and DNP, inhibitors of the generation of adenosine triphosphate); p-aminohippurate and tetraethylammonium (PAH and TEA, inhibitors of organic anion and cation transporters); and L- and D-isomers of natural amino acids. Results: 14C-Tyr exhibited affinity for systems L, A and ASC. 4-125I-mTyr and 3-125I-Tyr exhibited high specificity for system L, whereas 6-125I-mTyr and 125I-IMT exhibited affinity for both systems L and ASC. Uptake of 4-125I-mTyr was markedly reduced by incubation at 4 oC, and was not significantly inhibited by NaN3, DNP, PAH or TEA. The inhibition profiles of the L- and D-isomers of natural amino acids indicated that system L mediates the transport of 4-125I-mTyr. Conclusions: 4-125I-mTyr exhibited the greatest system L specificity (93.46±0.13%) of all of the tested amino acids.

  1. Correlation between cell survival and DNA single-strand break repair proficiency in the Chinese hamster ovary cell lines AA8 and EM9 irradiated with 365-nm ultraviolet-A radiation

    International Nuclear Information System (INIS)

    Cell survival parameters and the induction and repair of DNA single-strand breaks were measured in two Chinese hamster ovary cell lines after irradiation with monochromatic UVA radiation of wavelength 365 nm. The radiosensitive mutant cell line EM9 is known to repair ionizing-radiation-induced single-strand breaks (SSB) more slowly than the parent line AA8. EM9 was determined to be 1.7-fold more sensitive to killing by 365-nm radiation than AA8 at the 10% survival level, and EM9 had a smaller shoulder region on the survival curve (α = 1.76) than AA8 (α = 0.62). No significant differences were found between the cell lines in the initial yields of SSB induced either by γ-radiation (as determined by alkaline sucrose gradient sedimentation) or by 365-nm UVA (as determined by alkaline elution). For measurement of initial SSB, cells were irradiated at 0.5oC to minimize DNA repair processes. Rejoining of 365-nm induced SSB was measured by irradiating cells at 0.5oC, allowing them to repair at 37oC in full culture medium, and then quantitating the remaining SSB by alkaline elution. The repair of these breaks followed biphasic kinetics in both cell lines. EM9 repaired the breaks more slowly (T1/2 values of 1.3 and 61.3 min) than did AA8 (T1/2 values of 0.9 and 53.3 min), and EM9 also left more breaks unrepaired 90 min after irradiation (24% vs 8% for AA8). Thus, the sensitivity of EM9 to 365-nm radiation correlated with its deficiency in repairing DNA lesions revealed as SSB in alkaline elution. These results suggest that DNA may be a critical target in 365-nm induced cellular lethality and that the ability of AA8 and EM9 cells to repair DNA strand breaks may be related to their ability to survive 365-nm radiation. (author)

  2. Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients

    Institute of Scientific and Technical Information of China (English)

    Miao Li; Weiheng Su; Jie Wang; Francesco Pisani; Antonio Frigeri; Tonghui Ma

    2013-01-01

    In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica.

  3. Combined radiation-protective and radiation-sensitizing agents. II. Radiosensitivity of hypoxic or aerobic Chinese hamster fibroblasts in the presence of cysteamine and misonidazole: implications for the oxygen effect with Appendix on calculation of dose-modifying factors

    International Nuclear Information System (INIS)

    Experiments have been done to test whether a hypoxic cell radiosensitizing agent (misonidazole) can be combined with a radioprotecting agent (cysteamine) to equalize partially the radiation response of hypoxic and aerobic mammalian cells in tissue culture. The results indicate that cysteamine will protect against the radiosensitization of a hypoxic cell sensitizing drug (2.5 mM misonidazole) at much lower concentration than it will protect against the radiosensitization of oxygen (350 μM). Thus the addition of a radiation-protective drug tends to cancel the drug benefit of the radiosensitizer and therefore increases the differential response of hypoxic and aerobic cells rather than equalizing this response. The data suggest that even in situations where tumor tissue absorbs far less radioprotective drug than normal tissue (e.g., WR 2721), one might expect difficulties with the simultaneous administration of radiosensitizing and radioprotecting drugs

  4. 2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline-induced DNA adduct formation and mutagenesis in DNA repair-deficient Chinese hamster ovary cells expressing human cytochrome P4501A1 and rapid or slow acetylator N-acetyltransferase 2.

    Science.gov (United States)

    Bendaly, Jean; Zhao, Shuang; Neale, Jason R; Metry, Kristin J; Doll, Mark A; States, J Christopher; Pierce, William M; Hein, David W

    2007-07-01

    2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). In humans, NAT2*4 allele is associated with rapid acetylator phenotype, whereas NAT2*5B allele is associated with slow acetylator phenotype. We hypothesized that rapid acetylator phenotype predisposes humans to DNA damage and mutagenesis from MeIQx. Nucleotide excision repair-deficient Chinese hamster ovary cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alleles. CYP1A1 and NAT2 catalytic activities were undetectable in untransfected Chinese hamster ovary cell lines. CYP1A1 activity did not differ significantly (P > 0.05) among the CYP1A1-transfected cell lines. Cells transfected with NAT2*4 had 20-fold significantly higher levels of sulfamethazine N-acetyltransferase (P = 0.0001) and 6-fold higher levels of N-hydroxy-MeIQx O-acetyltransferase (P = 0.0093) catalytic activity than cells transfected with NAT2*5B. Only cells transfected with both CYP1A1 and NAT2*4 showed concentration-dependent cytotoxicity and hypoxanthine phosphoribosyl transferase mutagenesis following MeIQx treatment. Deoxyguanosine-C8-MeIQx was the primary DNA adduct formed and levels were dose dependent in each cell line and in the following order: untransfected < transfected with CYP1A1 < transfected with CYP1A1 and NAT2*5B < transfected with CYP1A1 and NAT2*4. MeIQx DNA adduct levels were significantly higher (P < 0.001) in CYP1A1/NAT2*4 than CYP1A1/NAT2*5B cells at all concentrations of MeIQx tested. MeIQx-induced DNA adduct levels correlated very highly (r2 = 0.88) with MeIQx-induced mutants. These results strongly support extrahepatic activation of MeIQx by CYP1A1 and a robust effect of human NAT2 genetic polymorphism

  5. 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

    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 is a...

  6. *609436 FIBROBLAST GROWTH FACTOR 21; FGF21 [OMIM

    Lifescience Database Archive (English)

    Full Text Available FIELD NO 609436 FIELD TI 609436 FIBROBLAST GROWTH FACTOR 21; FGF21 FIELD TX CLONING Nishimura et ... f hypoglycemic effects. FGF21-transgenic mice were lean , had lower fasted glucose levels, were resistant t ... and 29 obese Chinese individuals compared with 105 lean ... controls. In 29 healthy premenopausal Chinese wome ...

  7. Interspecific variation of intracellular localization and postirradiation movement of Ku70-protein in fibroblastic cells

    International Nuclear Information System (INIS)

    Ku (Ku70 and Ku80) Proteins are known as components of DNA-dependent protein kinase (DNA-PK) and play an important role for DNA repair. We previously reported that more than 70% of Ku proteins were located in cytoplasm of rat cells, the Ku proteins moved into nuclei of normal rat cells after X-irradiation, Ku proteins also moved into nuclei after X-irradiation but were not retained in nucleus of radiosensitive LEC rat cells. While reports have been shown about mechanisms on nuclear localization of Ku proteins, how Ku proteins export from nucleus is poorly understood. Here we show that C-terminal region of Ku70 protein is important for its cytoplasmic localization. When transfected into LEC rat cells, exogenous intact Ku70 (1-609) tagged with enhanced green fluorescent protein (EGFP-Ku70) localized mainly in the cytoplasm, whereas C-terminal-deletion mutant of Ku70 (1-593) tagged with EGFP (EGFP-Ku70D) was mainly localized in the nucleus. After X-irradiation, the endogenous intact EGFP-Ku70 once moved into nucleus, but returned into the cytoplasm. On the other hand, EGFP-Ku70D was retained in nucleus for two hours after X-irradiation. These results suggest that C-terminal region of Ku70 is included in the postirradiation nuclear export. Next, we investigated the intracellular localization of Ku70 proteins and the movement after X-irradiation of fibroblastic cells prepared from some mammalian species. Ku70 proteins were localized in nucleus and the postirradiation-extranuclear transport was not observed in human and African green monkey cells. On the other hand, Ku70 proteins were mainly localized in cytoplasm and moved into nucleus in mouse, Chinese hamster, Golden hamster, cotton rat, squirrel, cat and dog cells. These results may show that alternatively Ku70 protein is localized in the cytoplasm or nucleus depends on species and translocation of cytoplasmic Ku70 into nucleus is a response against low dose irradiation in fibroblasts of rodents, cats and dogs

  8. Interspecific variation of intracellular localization and postirradiation movement of Ku70-protein in fibroblastic cells

    Energy Technology Data Exchange (ETDEWEB)

    Endoh, Daiji; Hayashi, Masanobu [Rakuno Gakuen Univ., School of Veterinary Midicine, Ebetsu, Hokkaido (Japan); Okui, Toyo; Kawase, Shiro [Hokkaido Institute of Public Health, Sapporo, Hokkaido (Japan); Kon, Yasushiro [Hokkaido Univ., Graduate School of Veterinary Medicine, Sapporo, Hokkaido (Japan)

    2003-07-01

    Ku (Ku70 and Ku80) Proteins are known as components of DNA-dependent protein kinase (DNA-PK) and play an important role for DNA repair. We previously reported that more than 70% of Ku proteins were located in cytoplasm of rat cells, the Ku proteins moved into nuclei of normal rat cells after X-irradiation, Ku proteins also moved into nuclei after X-irradiation but were not retained in nucleus of radiosensitive LEC rat cells. While reports have been shown about mechanisms on nuclear localization of Ku proteins, how Ku proteins export from nucleus is poorly understood. Here we show that C-terminal region of Ku70 protein is important for its cytoplasmic localization. When transfected into LEC rat cells, exogenous intact Ku70 (1-609) tagged with enhanced green fluorescent protein (EGFP-Ku70) localized mainly in the cytoplasm, whereas C-terminal-deletion mutant of Ku70 (1-593) tagged with EGFP (EGFP-Ku70D) was mainly localized in the nucleus. After X-irradiation, the endogenous intact EGFP-Ku70 once moved into nucleus, but returned into the cytoplasm. On the other hand, EGFP-Ku70D was retained in nucleus for two hours after X-irradiation. These results suggest that C-terminal region of Ku70 is included in the postirradiation nuclear export. Next, we investigated the intracellular localization of Ku70 proteins and the movement after X-irradiation of fibroblastic cells prepared from some mammalian species. Ku70 proteins were localized in nucleus and the postirradiation-extranuclear transport was not observed in human and African green monkey cells. On the other hand, Ku70 proteins were mainly localized in cytoplasm and moved into nucleus in mouse, Chinese hamster, Golden hamster, cotton rat, squirrel, cat and dog cells. These results may show that alternatively Ku70 protein is localized in the cytoplasm or nucleus depends on species and translocation of cytoplasmic Ku70 into nucleus is a response against low dose irradiation in fibroblasts of rodents, cats and dogs

  9. The hamster cheek pouch model for field cancerization studies.

    Science.gov (United States)

    Monti-Hughes, Andrea; Aromando, Romina F; Pérez, Miguel A; Schwint, Amanda E; Itoiz, Maria E

    2015-02-01

    External carcinogens, such as tobacco and alcohol, induce molecular changes in large areas of oral mucosa, which increase the risk of malignant transformation. This condition, known as 'field cancerization', can be detected in biopsy specimens using histochemical techniques, even before histological alterations are identified. The efficacy of these histochemical techniques as biomarkers of early cancerization must be demonstrated in appropriate models. The hamster cheek pouch oral cancer model, universally employed in biological studies and in studies for the prevention and treatment of oral cancer, is also an excellent model of field cancerization. The carcinogen is applied in solution to the surface of the mucosa and induces alterations that recapitulate the stages of cancerization in human oral mucosa. We have demonstrated that the following can be used for the early detection of cancerized tissue: silver staining of nucleolar organizer regions; the Feulgen reaction to stain DNA followed by ploidy analysis; immunohistochemical analysis of fibroblast growth factor-2, immunohistochemical labeling of proliferating cells to demonstrate an increase of epithelial cell proliferation in the absence of inflammation; and changes in markers of angiogenesis (i.e. those indicating vascular endothelial growth factor activity, endothelial cell proliferation and vascular density). The hamster cheek pouch model of oral cancer was also proposed and validated by our group for boron neutron capture therapy studies for the treatment of oral cancer. Clinical trials of this novel treatment modality have been performed and are underway for certain tumor types and localizations. Having demonstrated the efficacy of boron neutron capture therapy to control tumors in the hamster cheek pouch oral cancer model, we adapted the model for the long-term study of field cancerized tissue. We demonstrated the inhibitory effect of boron neutron capture therapy on tumor development in field

  10. In vitro assembly of homopolymer and copolymer filaments from intermediate filament subunits of muscle and fibroblastic cells.

    OpenAIRE

    Steinert, P M; Idler, W W; Cabral, F; Gottesman, M M; Goldman, R D

    1981-01-01

    This paper presents evidence that the intermediate filament (IF) subunits of muscle cells (skeletin or desmin) and fibroblastic cells (decamin or vimentin) separately form homopolymer IF in vitro and, when mixed, prefer to form copolymer IF in vitro. Because they coexist in cells, they may also form copolymers in vivo. The IFs of baby hamster kidney fibroblasts (BHK-21) consist of a major subunit, decamin, and two minor subunits which, on the basis of two-dimensional gel and peptide mapping c...

  11. High resistance of fibroblasts from Mongolian gerbil embryos to cell killing and chromosome aberrations by X-irradiation

    International Nuclear Information System (INIS)

    Mongolian gerbil (Meriones unguiculatus) is known to be one of the most radioresistant animal species. In order to determine whether there is any correlation between mortality of mammals exposed to γ- or X-rays and radiation sensitivity of culture cells derived from different mammalian species, we have examined the X-ray survival curves of normal diploid fibroblasts from Mongolian gerbil embryos and compared with those of other cultured embryo cells from various laboratory animals and normal human. There was a big difference in cell survival to X-rays among different mammalian species. The D0 values of Mongolian gerbil cells ranged from 2.3 to 2.6 Gy which are twice as high as those of human cells. The mean D0 value of human cells was 1.1 Gy. Mouse, rat, Chinese hamster and Syrian/golden hamster cells showed similar D0 values ranging from 1.7 to 2.0 Gy. When cells were irradiated with 2 Gy of X-rays, three times longer mitotic delay was observed in human cells than in Mongolian gerbil cells. At this X-ray dose, furthermore, ten times more chromosome aberrations were detected in human cells than in Mongolian gerbil cells, and the frequencies of other rodent cells lay between the values for the two cell strains. These data indicate that the Mongolian gerbil cells are resistant to X-ray-induced cell killing and chromosome aberrations, and that radiation sensitivity of primarily cultured mammalian cells may be reflected by their radioresistance in vivo. (author)

  12. Establishment of a hamster lymphoma cell line

    Directory of Open Access Journals (Sweden)

    Abe,Shinji

    1974-08-01

    Full Text Available The establishment of a hamster lymphoma cell line was attempted. Simple mincing and trypsinization of lymphoma tissue resulted in a high degree of cell degeneration. The ascitic tumor cells produced by intraperitoneal transplantation of lymphoma tissue gave a better result. These ascitic cells grew and were cultured successively in medium consisting of RPMI 1640 and 20% fetal calf serum. Cells were round and grew in suspension. Accelerated cell growth was observed one month after starting the culture. In the stained preparations, cells were lymphoblastic. Cells were transplantable into new-born hamsters and produced tumors, but not in young adult hamsters.

  13. 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.

  14. Induction of lyme arthritis in LSH hamsters

    International Nuclear Information System (INIS)

    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

  15. Mycoplasma pneumoniae-induced hydrocephalus in hamsters.

    OpenAIRE

    Kohn, D F; Chinookoswong, N; Wang, J

    1984-01-01

    Hydrocephalus was induced in neonatal hamsters after intracerebral inoculation of Mycoplasma pneumoniae. Examination of the ependyma from affected animals by electron microscopy did not reveal mycoplasma. However, in an ependymal organ culture system, M. pneumoniae cytadsorbed to ependymal cells.

  16. [Infection of skin fibroblasts in animals with different levels of sensitivity to Leishmania infantum and Leishmania mexicana (Kinetoplastida: Trypanosomatidae)].

    Science.gov (United States)

    Minero, Miguel Angel; Chinchilla, Misael; Guerrero, Olga Marta; Castro, Alfredo

    2004-03-01

    Infection and multiplication of Leishmania infantum and L. mexicana inside of skin fibroblasts from hamsters, mice and rats was achieved. This process was demonstrated either by counting parasites inside the stained cells or by electronic microscopy studies. In addition multiplication rate differences in the cells from these rodent species were determined, for L. infantum as well as for L. mexicana. Parasite development in hamsters and mice fibroblasts was evident but there was not multiplication in rat cells showing that apparently they are refractory to Leishmania infection. These results suggest that the parasite affinity for each animal, as well as any intracellular environment resistance, could involve genetic factors in the parasite multiplication. On the other hand, presence of amastigote multiplication inside of parasitophorus vacuole, showed by electronic microscopy images, probes a true parasite transformation. Therefore it is suggested that fibroblasts could work as host cells for parasite survival and permanency in the infected animals. PMID:17357424

  17. 重组乙型肝炎疫苗(中国仓鼠卵巢细胞)免疫12年的效果研究%12 Years Immunological Effects of Hepatitis B Vaccine Made by Recombinant Deoxyribonucleic Acid Techniques in Chinese Hamster Ovary Cell

    Institute of Scientific and Technical Information of China (English)

    齐顺祥; 王锋; 张勇; 毕胜利; 张新江; 张建立; 张志勇; 郝志勇; 陈吉朝; 褚娟; 马景臣; 赵玉良

    2010-01-01

    目的 研究1997~1999年出生人群,接种重组乙型肝炎(乙肝)疫苗[Hepatitis B Vaccine Made by Recombinant Deoxyrlbonucleic Acid(DNA)Techniques in Chinese Hamster Ovary(CHO)Cell,HepB(CHO)]的免疫效果.方法 将正定县1997~1999年出生人群接种重组HepB(CHO)的三个乡作为研究现场,以户籍登记在册的全部儿童为研究对象,核实重组HepB(CHO)接种史,采集静脉血5ml,无菌分离血清,使用固相放射免疫试剂检测乙肝病毒表面抗原[Hepatitis B Virus(HBV)Surface Antigen,HBsAg]和抗乙肝病毒核心抗原抗体(Anti-HBV Core Antibody,Anti-HBc):抗乙肝病毒表面抗原抗体(Anti-HBV Surface Antibody,Anti-HBs)使用Abbott公司生产的微粒子酶免疫测定(Microparticle Enzyme lmmunoassay,MEIA)试剂定量检测.结果 免疫后10~12年的AntiHBs阳性率分别为71.0%、72.1%、68.2%,平均70.3%;Anti-HBs的几何平均浓度(Geometric Mean Concentration,GMC)分别为197.9mIU/ml(毫国际单位/毫升)、296.0mIU/ml、158.0mIU/ml,平均207.9mIU/ml.HBsAg阳性率为0.50%,Anti-HBc阳性率为2.26%.结论 重组HepB(CHO)免疫后10~12年效果良好.

  18. A three-step purification strategy for isolation of hamster TIG2 from CHO cells: characterization of two processed endogenous forms.

    Science.gov (United States)

    Busmann, Annette; Walden, Michael; Wendland, Martin; Kutzleb, Christian; Forssmann, Wolf-Georg; John, Harald

    2004-11-25

    We have recently isolated a bioactive, circulating protein of human tazarotene-induced gene-2 (TIG2) as the natural ligand of the orphan receptor ChemR23. Here we describe a simplified method for the isolation of hamster TIG2 protein from Chinese hamster ovary (CHO) cell supernatant. Using a heparin-affinity column followed by two reversed phase chromatography steps resulted in the isolation of pure biologically active material. Two processed bioactive forms of Chinese hamster TIG2 were identified by Edman sequencing and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) mass fingerprint analysis, representing the amino acid residues T20 to F156, and T20 to A155 of the 163 amino acid propeptide. Comparison with the predicted aa-sequence indicates a mutation or modification within the C-terminal end of the peptide. PMID:15522723

  19. SV40 DNA amplification and reintegration in surviving hamster cells after 60Co γ-irradiation

    International Nuclear Information System (INIS)

    SV40-transformed Chinese hamster embryo cells were exposed to 60Co γ-irradiation and the fate of the integrated SV40 sequences was pursued over a period of 20 days following radiation exposure. As shown by colony hybridization, integrated SV40 sequences were amplified in surviving and non-surviving cells. At later times, however, clonal sublines of surviving cells grown for 20-30 cell generations after irradiation had lost most of their amplified SV40 copies but showed altered restriction fragment patterns indicating reintegration of SV40 sequences at new sites of the hamster genome. This suggest that 60Co γ-irradiation can generate mutations by inducing over-replication of chromosome segments that are then substrates of enzymatic rearrangements. (author)

  20. 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.

  1. Decreased adult neurogenesis in hibernating Syrian hamster.

    Science.gov (United States)

    León-Espinosa, Gonzalo; García, Esther; Gómez-Pinedo, Ulises; Hernández, Félix; DeFelipe, Javier; Ávila, Jesús

    2016-10-01

    Generation of new neurons from adult neural stem cells occurs in the dentate gyrus (DG) of the hippocampus and the lateral walls of the lateral ventricles. In this article, we study the neurogenesis that takes place during the hibernation of the Syrian hamster (Mesocricetus auratus). Using a variety of standard neurogenesis markers and 5-bromo-2-deoxyuridine (BrdU) incorporation, we describe a preferential decrease in the proliferation of newborn neurons in the subventricular zone (SVZ) of the hibernating hamsters (torpor) rather than in the hippocampus. Furthermore, we demonstrate that the proliferative capacity is recovered after 3-4days of torpor when arousal is triggered under natural conditions (i.e., not artificially provoked). In addition, we show that tau3R, a tau isoform with three microtubule-binding domains, is a suitable marker to study neurogenesis both in the SVZ and subgranular zone (SGZ) of the Syrian hamster brain. PMID:27436535

  2. Histopathology of Lyme arthritis in LSH hamsters

    International Nuclear Information System (INIS)

    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

  3. Human follicular fluid adverses hamster spermatozoa motility.

    Science.gov (United States)

    Wetzels, A; Goverde, H J; Bastiaans, L A; Rolland, R

    1989-01-01

    To determine the optimal conditions for in vitro spermatozoa vitality, human and hamster spermatozoa were incubated at 37 degrees C in T6 medium supplemented with different biologic fluids (10% v/v). The fluids tested were human serum (HUS), hamster serum (HAS), and human follicular fluid (HUF). After incubation the spermatozoa were investigated for their qualitative and quantitative motility. Human spermatozoa maintained a good vitality in all fluids tested (approximately 25% motility after 18-h incubation). The hamster spermatozoa had after an incubation of 4 h a motility of 28.4% in HUS, 14.2% in HAS, and 2.2% in HUF. The quality of the motility was also extremely low in HUF, whereas it was adequate in HUS and in HAS. The presence of species-specific substances in mammalian follicular fluid is discussed. PMID:2589906

  4. Identification of the Syrian hamster cardiomyopathy gene.

    Science.gov (United States)

    Nigro, V; Okazaki, Y; Belsito, A; Piluso, G; Matsuda, Y; Politano, L; Nigro, G; Ventura, C; Abbondanza, C; Molinari, A M; Acampora, D; Nishimura, M; Hayashizaki, Y; Puca, G A

    1997-04-01

    The BIO14.6 hamster is a widely used model for autosomal recessive cardiomyopathy. These animals die prematurely from progressive myocardial necrosis and heart failure. The primary genetic defect leading to the cardiomyopathy is still unknown. Recently, a genetic linkage map localized the cardiomyopathy locus on hamster chromosome 9qa2.1-b1, excluding several candidate genes. We now demonstrate that the cardiomyopathy results from a mutation in the delta-sarcoglycan gene that maps to the disease locus. This mutation was completely coincident with the disease in backcross and F2 pedigrees. This constitutes the first animal model identified for human sarcoglycan disorders. PMID:9097966

  5. Membrane proteins of dense lysosomes from Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    In this work membrane proteins from lysosomes were studied in order to gain more information on the biogenesis and intracellular sorting of this class of membrane proteins. Membrane proteins were isolated from a purified population of lysosomes. These proteins were then examined for various co- and post-translational modifications which could serve as potential intracellular sorting signals. Biochemical analysis using marker enzymatic activities detected no plasma membrane, Golgi, endoplasmic reticulum, peroxisomes, mitochondria, or cytosol. Analysis after incorporation of [3H]thymidine or [3H]uridine detected no nuclei or ribosomes. A fraction containing integral membrane proteins was obtained from the dense lysosomes by extraction with Triton X-114. Twenty-three polypeptides which incorporated both [35S]methionine and [3H]leucine were detected by SDS PAGE in this membrane fraction, and ranged in molecular weight from 30-130 kDa. After incorporation by cells of various radioactive metabolic precursors, the membrane fraction from dense lysosomes was examined and was found to be enriched in mannose, galactose, fucose, palmitate, myristate, and sulfate, but was depleted in phosphate. The membrane fraction from dense lysosomes was then analyzed by SDS PAGE to determine the apparent molecular weights of modified polypepties

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

    International Nuclear Information System (INIS)

    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.)

  7. CD147 overexpression promotes tumorigenicity in Chinese hamster ovary cells.

    Science.gov (United States)

    Yong, Yu-Le; Liao, Cheng-Gong; Wei, Ding; Chen, Zhi-Nan; Bian, Huijie

    2016-04-01

    CD147 overexpresses in many epithelium-originated tumors and plays an important role in tumor migration and invasion. Most studies aim at the role of CD147 in tumor progression using tumor cell models. However, the influence of abnormal overexpression of CD147 on neoplastic transformation of normal cells is unknown. Here, the role of CD147 in malignant phenotype transformation in CHO cells was investigated. Three CHO cell lines that stably overexpressed CD147 (CHO-CD147), EGFP-CD147 (CHO-EGFP-CD147), and EGFP (CHO-EGFP) were generated by transfection of plasmids containing human CD147, EGFP-human CD147, and EGFP genes into CHO cells. Cell migration and invasion were detected by wound healing and transwell matrix penetration assay. Trypan blue exclusion, MTT, cell cycle analysis, and BrdU cell proliferation assay were used to detect cell viability and cell proliferation. Annexin V-FITC analysis was performed to detect apoptosis. We found that CD147 overexpression promoted the migration and invasion of CHO cells. CD147 accelerated the G1 to S phase transition and enhanced the CHO cell proliferation. Overexpression of CD147 inhibited both early- and late-stages of apoptosis of CHO-CD147 cells, which is caused by serum deprivation. CHO-EGFP-CD147 cells showed an increased anchorage-independent growth compared with CHO-EGFP cells as detected by soft-agar colony formation assay. The tumors formed by CHO-CD147 cells in nude mice were larger and coupled with higher expression of proliferating cell nuclear antigen and Ki-67 than that of CHO cells. In conclusion, human CD147 overexpression induces malignant phenotype in CHO cells. PMID:26676266

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

    International Nuclear Information System (INIS)

    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 hPRU106 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 hPRU106 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 hPRL11-199 fragments, apparently the result of a proteolytic process. (author)

  9. Studies on adaptive responses in Chinese hamster cells

    International Nuclear Information System (INIS)

    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

  10. Chinese hamster ovary cell lysosomes rapidly exchange contents

    OpenAIRE

    1987-01-01

    We have used cell fusion to address the question of whether macromolecules are rapidly exchanged between lysosomes. Donor cell lysosomes were labeled by the long-term internalization of the fluid- phase pinocytic markers, invertase (sucrase), Lucifer Yellow, FITC- conjugated dextran, or Texas red-conjugated dextran. Recipient cells contained lysosomes swollen by long-term internalization of dilute sucrose or marked by an overnight FITC-dextran uptake. Cells were incubated for 1 or 2 h in mark...

  11. 人β-珠蛋白核基质附着区介导表达载体稳定附着于中国仓鼠卵巢细胞%Expression vector mediated by human β-globin matrix attachment region functions as stable episomes in Chinese hamster ovary cells

    Institute of Scientific and Technical Information of China (English)

    吴向楠; 王天云; 杨瑞; 王俪; 王芳

    2013-01-01

    目的 研究人β-珠蛋白核基质附着区是否能够介导表达载体稳定附着于中国仓鼠卵巢(CHO)细胞.方法 人β-珠蛋白MAR序列克隆到pEGFP-C1构建重组质粒载体pEGFP-MAR,转染CHO细胞,使用Hirt裂解法提取细胞中附着体质粒,CaCI2法转化附着体质粒到宿主大肠杆菌DH5a中,提取质粒,酶切,测序分析.结果 还原质粒双酶切和单酶切结果均与转染前质粒酶切结果一致;测序分析得知还原质粒与转染前质粒中插入片段DNA序列相同.结论 人β-珠蛋白MAR序列重组载体在CHO细胞中以附着体形式被完整还原出来.还原质粒酶切结果和测序结果均与转染前质粒一致.%Objective To study the human β-globin matrix attachment region(MAR) sequence mediated vector whether exist as stable episomes in transfected Chinese hamster ovary(CHO) cells.Methods Recombinant plasmid vector pEGFPMAR was constructed by thrusting the amplified human β-globin MAR sequence into the parental pEGFP-C1.CHO cells were transfected both with pEGFP-C1 and reconstructed vector.Episomal vectors from the stable monoclonal cell lines were extracted by modificated Hirt cracking protocol.Then CaCl2 method was performed to transform episomal vectors into the host bacteria E.coli DH5α,and the plasmid from the transformed E.coli DH5α was extracted.In the end,enzyme digestion identification and sequencing analysis were performed to detect the rescued plasmid and the original plasmid.Results Both double enzyme and single enzyme to completely digested the rescued plasmids and the original plassmid showed the same result.The sequencing analysis showed that the inserted sequence of rescued plasmid was identical to the original DNA sequence.Conclusion Human β-globin MAR characteristic sequence-based vector can be completely rescued from cultured CHO cells.The results of enzyme digestion identification and sequencing analysis are consistent in the rescued plasmids and the original plasmid.

  12. 蓖麻质膜水通道蛋白PIP1.3在仓鼠卵巢细胞中的转运功能%Castor Plasma Membrane Aquaporin (PIP1.3) in Vitro Transprot in Chinese Hamster Ovary

    Institute of Scientific and Technical Information of China (English)

    董乐; 戴聪杰; 王芳; 王云; 朱国立; 谢小宾; 许珊珊; 刘灿阳; 林婷

    2014-01-01

    为研究蓖麻质膜水通道蛋白PIP1.3的转运功能,采用RT-PCR技术扩增基因PIP1.3的全长编码区cDNA序列(861 bp),将该序列亚克隆至真核表达载体pcDNA3.1/Myc-His A,酶切、测序分析表明,重组质粒pcDNA3.1PIP1.3-Myc-His阅读框架正确。将pcDNA3.1PIP1.3-Myc-His和连接氯离子敏感性绿色荧光蛋白突变体(EYFP-H148Q-V163S)的pcDNA3.1Hygro-EY-FP-H148Q-V163S重组质粒稳定共转染至中国仓鼠卵巢(Chinese hamster ovary, CHO)细胞中, RT-PCR和Western blot分析表明, PIP1.3的mRNA和蛋白质在选定CHO细胞克隆中高表达。分别通过荧光法和同位素标记的14C-甘油摄入实验测定该CHO细胞对水分和甘油的通透性,结果表明,该CHO细胞表达的PIP1.3对水分子的转运能力很低,但能选择性转运甘油。%The encoding sequence of plasma membrane aquaporin gene (PIP1.3) in castor (Ricinus communis L.) was ampliifed with RT-PCR and inserted into pcDNA3.1/Myc-His A vector, double enzyme digestion analy-sis and DNA sequencing confirmed that recombination plasmid was successfully constructed. pcD-NA3.1PIP1.3-Myc-His and pcDNA3.1Hygro-EYFP-H148Q-V163S plasmids linking Cl--sensitive EYFP mutant (EYFP-H148Q-V163S) were transfected in CHO cells. The stable transfection of CHO cells was analysis with RT-PCR and Western blot. The results showed that PIP1.3 mRNA and protein were overexpressed in cell line screened. Permeabilities of PIP1.3 expressing CHO cells for water and glycerol were measured respectively by lfuorescence method and carbon labeling experiment. The results showed that permeability of PIP1.3 express-ing CHO cells for water was low, but high for glycerol.

  13. Isolation and properties of fibroblast mutants overexpressing an altered Na+/H+ antiporter

    International Nuclear Information System (INIS)

    A new method based on the toxicity of low intracellular pH (pH/sub i/) was developed to isolate fibroblasts variants overexpressing Na+/H+ antiport activity. Chinese hamster lung fibroblasts (CCL39) were incubated for 60 min in medium containing 50 mM NH4Cl. Removal of external NH+4 induced in a rapid and lethal intracellular acidification when the Na+/H+ antiporter was inhibited during the 60 min of the pH/sub i/ recovery phase. The inhibition was provoked either by adding 5-(N-methyl, N-propyl)amiloride (MPA, LD50= 0.3 μM) or by reducing external [Na+] (LD50 = 25 mM). Progressively increasing the MPA concentration during the acid-load selection led to the isolation of two stable variants: AR40 and AR300, resistant, respectively, to 40 and 300 μM MPA. In response to an acid-load, these variants display a much higher rate of pH/sub i/ recovery due to an overexpression of Na+/H+ antiport activity. In addition, AR40 and AR300 have an altered Na+/H+ antiporter. Alternatively reducing Na+ concentration of the pH/sub i/ recovery saline medium in a stepwise manner led to the selection of another class of variants (DD8 and DD12) also characterized by an altered Na+/H+ antiporter and an increased expression level. The 10-fold increased rate of amiloride-sensitive Na+ influx of DD12 is accounted for by a 4-fold increase in V/sub max/ and a 2.5-fold increase in affinity for Na+ or Li+ at the external site. In conclusion, the genetic approach presented here: (i) provides a general and specific method for selecting variants of the Na+/H+ antiporter with increased expression levels and/or with structural alterations and (ii) demonstrates that the external Na+-and amiloride-binding sites are not identical, since they can be genetically altered independently of each other

  14. Insulin-like growth factor II peptide fusion enables uptake and lysosomal delivery of α-N-acetylglucosaminidase to mucopolysaccharidosis type IIIB fibroblasts

    Science.gov (United States)

    Kan, Shih-hsin; Troitskaya, Larisa A.; Sinow, Carolyn S.; Haitz, Karyn; Todd, Amanda K.; Di Stefano, Ariana; Le, Steven Q.; Dickson, Patricia I.; Tippin, Brigette L.

    2014-01-01

    Enzyme replacement therapy for mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo B syndrome) has been hindered by inadequate mannose 6-phosphorylation and cellular uptake of recombinantly produced human α-N-acetyl-glucosamindase (rhNAGLU). We expressed and characterized a modified, recombinant human NAGLU fused to the receptor binding motif of insulin-like growth factor-II (rhNAGLU-IGF-II) to enhance its ability to enter cells using the cation-independent mannose 6-phosphate receptor, which is also the receptor for IGF-II (at a different binding site). RhNAGLU-IGF-II was stably expressed in Chinese hamster ovary cells, secreted and purified to apparent homogeneity. The Km and pH optimum of the fusion enzyme was similar to those reported for rhNAGLU. Both intracellular uptake and confocal microscopy suggested MPS IIIB fibroblasts readily take up the fusion enzyme via receptor-mediated endocytosis that was significantly inhibited (p<0.001) by monomeric IGF-II peptide. Glycosaminoglycan storage was reduced by 60% (p<0.001) to near background levels in MPS IIIB cells after treatment with rhNAGLU-IGF-II, with half-maximal correction at concentrations of 3–12 pM. Similar cellular uptake mechanism via the IGF-II receptor was also demonstrated in two different brain tumor-derived cell lines. Fusion of NAGLU to IGF-II enhanced its cellular uptake while maintaining enzymatic activity, supporting its potential as a therapeutic candidate for MPS IIIB. PMID:24266751

  15. Modulation of the effects of alveolar macrophages on lung fibroblast collagen production rate

    International Nuclear Information System (INIS)

    Alveolar macrophages (AM) may function as effector cells that can either stimulate or inhibit lung fibroblast collagen production. However, conditions that determine the predominant effect of AM on fibroblasts are not well understood. To delineate factors that modulate the effects of AM on lung fibroblasts, we studied the interaction of AM products and fibroblasts in vitro. The AM were obtained by bronchoalveolar lavage of hamsters with bleomycin-induced pulmonary fibrosis. Conditioned medium (CM) from the AM cultures was incubated in varying amounts with lung fibroblast (IMR-90) cultures. After metabolic labeling with [3H]proline, fibroblast collagen production based on procollagen-specific radioactivity was determined. Macrophage CM in concentrations greater than 5% suppressed collagen production, an event attributed to the macrophage-derived suppressive factor that we have previously characterized. Macrophages were also determined to produce PGE2 in culture. Authentic PGE2 at concentrations found in CM was found to suppress fibroblast collagen production, indicating that AM-derived PGE2 contributes to the suppressive activity in CM. To examine possible stimulatory factors in CM, the fibroblasts were preincubated with indomethacin. This approach was based on our previous observation that AM-derived suppressive factor increases endogenous fibroblast PGE2 and that its activity can be blocked by indomethacin. Macrophage CM in a concentration of 20% did not suppress the collagen production of indomethacin-treated fibroblasts. However, CM concentrations of 5 and 10% increased collagen production (173 and 143% of control values, respectively), indicating the presence of stimulatory factor(s) in macrophage-conditioned medium

  16. Ahne hamster lõikuskuul/ Tambet Kaugema

    Index Scriptorium Estoniae

    Kaugema, Tambet

    2010-01-01

    Eesti Nuku- ja Noorsoteatri jõululavastusest "Ahne hamster ja värvilised jäälilled", autor Miloš Macourek, tõlkija Leo Metsar, lavastaja ja muusikaline kujundaja Virko Annus, mängib Tarmo Männard. Esietendus 21. novembril Köismäe tornis

  17. Combined treatment of 4-EPI-DOXORUBICIN and radiation on hamster lung cells

    International Nuclear Information System (INIS)

    The purpose of this study was to test the type and the degree of cytotoxic effects of epirubicin and radiation in combined treatment on Chinese hamster lung cells in vitro. Experiments were performed with proliferating tissue culture cells. Cell kill was determined by colony-forming ability. The maximum killing effect were obtained when simultaneous action of drug treatment and irradiation occurred. Their interaction was synergistic. Synergism depended on time of drug incubation (epirubicin present for 1 h). Slight antagonism was noted after prolonged drug action (24 h)

  18. The thermal sensitivity of normal and ataxia telangiectasia human fibroblasts

    International Nuclear Information System (INIS)

    Human normal and ataxia telangiectasia (AT) heterozygote and homozygote cell strains were heated at 42.0 and 45.00C to determine their thermal responses. All cell strains had approximately the same thermal sensitivity and were less thermally sensitive than Chinese hamster cells or many other rodent cell lines reported in the literature. No shoulders were observed on the survival curves for heating at 42.0 or 45.00C. Thermal tolerance developed in both the normal and AT cells strains with heating for prolonged intervals at 42.0GAMMA

  19. Metabolism of radiohafnium in rats and hamsters: a possible analog of plutonium for metabolic studies

    International Nuclear Information System (INIS)

    The metabolism of radiohafnium (175Hf + 181Hf) was studied in male Sprague-Dawley rats and Chinese hamsters for periods of up to 168 days. The results were compared with similar data for 239Pu in the same rat strain. In rats and hamsters the radiohafnium organ distribution was skeleton > skin > muscle > liver at about 7 days postinjection. Retention of radiohafnium and plutonium was similar in plasma and liver, as were the retention time observed for other organs: Absorption of radiohafnium from the gastrointestinal tract of rats was <0.05%. Biochemical studies showed that the radiohafnium was bound mainly to the iron-transport protein, transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium. The metabolic behavior of radiohafnium mimics, to a large extent, that of plutonium, and it is suggested that radiohafnium can serve as a non-α-particle-emitting analog of plutonium for metabolic, biochemical, and selected human investigations

  20. The metabolism of radiohafnium in rats and hamsters: a possible analog of plutonium for metabolic studies

    International Nuclear Information System (INIS)

    The metabolism of radiohafnium (175Hf + 181Hf) was studied in male Sprague-Dawley rats and Chinese hamsters for periods of up to 168 days. The results were compared with similar data for 239Pu in the same rat strain. In rats and hamsters the radiohafnium organ distribution was skeleton greater than skin greater than muscle greater than liver at about 7 days postinjection. Retention of radiohafnium and plutonium was similar in plasma and liver, as were the retention times observed for other organs: Absorption of radiohafnium from the gastrointestinal tract of rats was less than 0.05%. Biochemical studies showed that the radiohafnium was bound mainly to the iron-transport protein, transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium. The metabolic behavior of radiohafnium mimics, to a large extent, that of plutonium, and it is suggested that radiohafnium can serve as a non-alpha-particle-emitting analog of plutonium for metabolic, biochemical, and selected human investigations

  1. Ligand-affinity cloning and structure of a cell surface heparan sulfate proteoglycan that binds basic fibroblast growth factor.

    OpenAIRE

    Kiefer, M C; Stephans, J C; Crawford, K; Okino, K.; Barr, P.J.

    1990-01-01

    Expression cloning of cDNAs encoding a basic fibroblast growth factor (FGF) binding protein confirms previous hypotheses that this molecule is a cell-surface heparan sulfate proteoglycan. A cDNA library constructed from a hamster kidney cell line rich in FGF receptor activity was transfected into a human lymphoblastoid cell line. Clones expressing functional basic FGF binding proteins at their surfaces were enriched by panning on plastic dishes coated with human basic FGF. The amino acid sequ...

  2. Bioactivation of diethylstilbestrol by the Syrian hamster kidney

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.P.

    1987-01-01

    Male Syrian golden hamsters chronically exposed to diethylstilbestrol (DES) develop renal adenocarcinomas with an incidence approaching 100%. The ability of the hamster kidney to bioactivate DES was assessed using hamster kidney slices. The male hamster renal cortex has a 2- to 5-fold greater capacity to irreversibly bind ({sup 3}H)DES as compared with female hamster renal cortex and with male hamster renal medulla. Incubation of the tissue under anaerobic conditions inhibited the metabolism and irreversible binding of ({sup 3}H)DES. Gel electrophoresis analysis of covalently modified proteins revealed several radioactive peaks indicating that specific adduct formation had occurred. The cytochrome P-450 inhibitors SKF 525-A, metyrapone, carbon monoxide, butylated hydroxytoluene, and dicumarol decreased the irreversible binding of ({sup 3}H)DES to renal cortical protein by 38 to 72%.

  3. Bioactivation of diethylstilbestrol by the Syrian hamster kidney

    International Nuclear Information System (INIS)

    Male Syrian golden hamsters chronically exposed to diethylstilbestrol (DES) develop renal adenocarcinomas with an incidence approaching 100%. The ability of the hamster kidney to bioactivate DES was assessed using hamster kidney slices. The male hamster renal cortex has a 2- to 5-fold greater capacity to irreversibly bind [3H]DES as compared with female hamster renal cortex and with male hamster renal medulla. Incubation of the tissue under anaerobic conditions inhibited the metabolism and irreversible binding of [3H]DES. Gel electrophoresis analysis of covalently modified proteins revealed several radioactive peaks indicating that specific adduct formation had occurred. The cytochrome P-450 inhibitors SKF 525-A, metyrapone, carbon monoxide, butylated hydroxytoluene, and dicumarol decreased the irreversible binding of [3H]DES to renal cortical protein by 38 to 72%

  4. 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. PMID:12472877

  5. Tumor-related gene changes in immunosuppressive Syrian hamster cholangiocarcinoma.

    Science.gov (United States)

    Juasook, Amornrat; Aukkanimart, Ratchadawan; Boonmars, Thidarut; Sudsarn, Pakkayanee; Wonkchalee, Nadchanan; Laummaunwai, Porntip; Sriraj, Pranee

    2013-10-01

    The results of a previous study demonstrated that prednisolone enhanced cholangiocarcinogenesis. Therefore, to clarify molecular changes during immunosuppressive cholangiocarcinogenesis, Syrian hamsters were divided into 8 groups: uninfected controls; immunosuppressed Syrian hamsters using prednisolone (P); normal Syrian hamsters administered N-nitrosodimethylamine (ND); immunosuppressed Syrian hamsters administered N-nitrosodimethylamine (NDis); normal Syrian hamsters infected with Opisthorchis viverrini (OV); immunosuppressed Syrian hamsters infected with O. viverrini (OVis); normal Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCA); and immunosuppressed Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCAis). Syrian hamster livers were used for analysis of tumor-related gene expression and immunohistochemistry through cytokeratin 19 (CK19) and proliferating cell nuclear antigen (PCNA) staining. The tumor-related gene expression results show that CCAis groups at all time points exhibited upregulation of COX-2, IL-6, SOD1, CAT and iNOS and downregulation of p53, which correlated with the predominant expression of CK19 and PCNA in liver tissue. These results suggest that prednisolone enhances cholangiocarcinoma development, which was confirmed by molecular changes. PMID:23645518

  6. Morphological transformation of an established Syrian hamster dermal cell with the anti-tussive agent noscapine.

    Science.gov (United States)

    Porter, R; Parry, E M; Parry, J M

    1992-05-01

    Following exposure to the alkaloid noscapine hydrochloride over a concentration range of 10-120 micrograms/ml immortal cultures of Syrian hamster dermal fibroblasts were shown to undergo morphological transformation. The resultant transformed foci produced cultures which were anchorage independent as confirmed by soft agar tests. Karyotype analysis of a noscapine transformed colony demonstrated an increase in chromosome number compared to the immortal culture and the non-random duplication of a translocated chromosome 9 previously identified in the immortal culture. These data indicate that noscapine, which has previously been shown to be a spindle inhibitor and inducer of polyploidy in cultured cells, is capable of inducing in vitro cell transformation. Such data indicate a carcinogenic potential for this widely used cough suppressant. PMID:1602976

  7. Study on the immuno-effects and influencing factors of Chinese Hamster Ovary (CHO) cell hepatitis B vaccine among adults, under different dosages%不同剂量国产重组酵母乙型肝炎疫苗成年人免疫效果及影响因素研究

    Institute of Scientific and Technical Information of China (English)

    张卫; 马建新; 张海燕; 王晨; 杨鹏; 李辉; 孙美平; 贺雄; 庞星火; 林长缨; 韩莉莉; 李立秋; 高培; 林晖; 龚晓红; 黄芳; 唐雅清

    2010-01-01

    Objective 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. Methods 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 tg 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. Results 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<100 mIU/ml as the low/non-response standard, the low response and non-response rates were 34.3% and 17.4% respectively. The geometric mean titers(GMT)of 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.Conclusion 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.%目的 通过随机双盲对照试验,评价10μg和20μg国产重组酵母(CHO)乙型肝炎(乙肝)疫

  8. Sperm functional changes and fertilization in vitro in co-culture with human skin fibroblasts.

    Science.gov (United States)

    Wetzels, A M; Van der Auwera, I; Bastiaans, B A; Goverde, H J; Hollanders, H M; Hamilton, C J

    1995-01-01

    This study was undertaken to evaluate the effects of human skin fibroblast monolayers on human sperm function and fertilization in vitro. Sperm function was evaluated using the hamster oocyte penetration assay (HOPA) and zona binding assay (ZBA) in medium alone and in co-culture with human skin fibroblast monolayers and suspensions. The ZBA was also studied in fibroblast conditioned medium and in bovine oviduct cell monolayers and suspensions. Fertilization was measured both in in-vitro fertilization (IVF) couples with a normal semen analysis (first study; randomized) and in IVF couples with subnormal semen analysis (second study; each patient served as its own control). The HOPA results were not significantly different with or without fibroblasts. In all co-culture situations and in conditioned medium the ZBA scored significantly lower than medium alone. No significant differences with respect to IVF were observed between the co-culture and the control group in either study. The mean fertilization rate per patient was approximately 60% in the group with normal semen analysis and approximately 25% in the group with abnormal semen analysis. From this study we conclude that although co-culture with human skin fibroblasts and epithelial cells influences the results of some sperm function tests, it does not influence fertilization in vitro. PMID:7745043

  9. Radiation-induced anorexia in Syrian hamsters

    International Nuclear Information System (INIS)

    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.)

  10. Radiation-induced anorexia in Syrian hamsters

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-10-01

    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.

  11. Cultivation of hamster bone marrow haematopoietic stem and progenitor cells

    Directory of Open Access Journals (Sweden)

    Kovačević-Filipović Milica

    2010-01-01

    Full Text Available Hamster, a hibernating animal, is an important experimental model in research on the influence of hypothermia on different physiological processes. A simple procedure for cultivation and identification of hamster hematopoetic stem cells (HSC and hematopoetic progenitor cells (HPC is a premise for a successful investigation upon hypothermia effects on hematopoiesis. The aim of this work was to evaluate the utilization of commercially available methylcellulose media (MC and recombinant mouse and human cytokines for hamster HSC and HPC assays, in order to enable further studies on these cells. Hamster bone marrow mononuclear cells (BMMNC were plated in MC containing cytokines that support mouse or human HPC growth. Also, BMMNC were resuspended in cytokine supplemented liquid media and incubated for 5 weeks with a four day monitoring of viable cell number. We demonstrated that hamster hematopoietic progenitor cells committed for erythroid lineage and myeloid lineage successfully formed recognizable colonies in both mouse and human MC, while multipotent progenitor cells formed colonies only in mouse MC. We also defined conditions for the evaluation of hamster HSC activity in liquid cultures, based on continuous 5 weeks HSC proliferation. The obtained results verify the utilization of mouse specific MC for further research on hamster HPC biology during hypothermia.

  12. Protective effect of butylated hydroxytoluene (BHT) against the clastogenic acitivity of cadmium chloride and potassium dichromate in hamster ovary cells

    OpenAIRE

    Grillo Claudia A.; Seoane Analía I.; Dulout Fernando N.

    1999-01-01

    The effect of butylated hydroxytoluene (BHT), a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC) and potassium dichromate (PD) in Chinese hamster ovary (CHO) cells was studied both at metaphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the presence of PD (6.0, 9.0 or 12.0 mM), BHT (1.0 mg/ml), or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mM), BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-tel...

  13. Susceptibility of Djungarian hamsters (Phodopus sungorus) to Neospora caninum infection.

    Science.gov (United States)

    Uchida, Yuko; Ike, Kazunori; Kurotaki, Tetsuro; Takeshi, Midori; Imai, Soichi

    2003-03-01

    Djungarian hamsters were examined for the susceptibility to Neospora caninum infection. After 29 Djungarian hamsters were intraperitoneally inoculated with 5 x 10(6) N. caninum tachyzoites of JPA1 strain, some animals showed symptoms such as ataxia, and many tissue cysts were detected in the brain and a cyst in the muscular tunics of stomach. Especially, more than 100 cysts per head were observed after 5 weeks post inoculation. It is suggested that the Djungarian hamster is a model useful to examine neosporosis. PMID:12679575

  14. Golden hamsters are nocturnal in captivity but diurnal in nature.

    Science.gov (United States)

    Gattermann, Rolf; Johnston, Robert E; Yigit, Nuri; Fritzsche, Peter; Larimer, Samantha; Ozkurt, Sakir; Neumann, Karsten; Song, Zhimin; Colak, Ercüment; Johnston, Joan; McPhee, M Elsbeth

    2008-06-23

    Daily activity rhythms are nearly universal among animals and their specific pattern is an adaptation of each species to its ecological niche. Owing to the extremely consistent nocturnal patterns of activity shown by golden hamsters (Mesocricetus auratus) in the laboratory, this species is a prime model for studying the mechanisms controlling circadian rhythms. In contrast to laboratory data, we discovered that female hamsters in the wild were almost exclusively diurnal. These results raise many questions about the ecological variables that shape the activity patterns in golden hamsters and the differences between laboratory and field results. PMID:18397863

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

    Science.gov (United States)

    Hjortoe, Gertrud Malene; Weilguny, Dietmar; Willumsen, Berthe Marie

    2005-01-01

    Elk3 belongs to the Ets family of transcription factors, which are regulated by the Ras/mitogen-activated protein kinase-signaling pathway. In the absence of Ras, this protein is a strong inhibitor of transcription and may be directly involved in regulation of growth by downregulating 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 is a target of the Ras-Raf-MAPK pathway, and cotransfections with constitutively active H-ras relieves its negative transcriptional activity. No cells stably expressing exogenous Elk3 could be obtained, possibly due to an unspecified toxic or growth retarding effect. These findings support a possible role for Elk3 in growth regulation and reveal a high degree of homology for this protein across species. PMID:15684718

  16. Lipids of hamster cheek pouch epithelium.

    Science.gov (United States)

    Whittle, S; Swartzendruber, D C; Kremer, M; Squier, C A; Wertz, P W

    1997-09-01

    The hamster cheek pouch is a much used but incompletely understood experimental model. In particular, the cheek pouch epithelial lipids, which are important for permeability barrier function as well as other aspects of epithelial biology, have not been completely characterized. In the present study, the complete lipid class composition has been determined by thin-layer chromatography in conjunction with photodensitometry. The major lipid classes were phospholipids, free sterols, and ceramides. Minor amounts of monohexosylceramides, sterol esters, fatty acids, and triglycerides were also present. Significant amounts of covalently bound omega-hydroxyceramide was also detected. Transmission electron micrographs reveal extensive, largely paired, lipid bilayers in the intercellular spaces of the stratum corneum. PMID:9307937

  17. Experimental Models in Syrian Golden Hamster Replicate Human Acute Pancreatitis

    OpenAIRE

    Yunan Wang; Abudurexiti Kayoumu; Guotao Lu; Pengfei Xu; Xu Qiu; Liye Chen; Rong Qi; Shouxiong Huang; Weiqin Li; Yuhui Wang; George Liu

    2016-01-01

    The hamster has been shown to share a variety of metabolic similarities with humans. To replicate human acute pancreatitis with hamsters, we comparatively studied the efficacy of common methods, such as the peritoneal injections of caerulein, L-arginine, the retrograde infusion of sodium taurocholate, and another novel model with concomitant administration of ethanol and fatty acid. The severity of pancreatitis was evaluated by serum amylase activity, pathological scores, myeloperoxidase acti...

  18. Clozapine chronically suppresses alcohol drinking in Syrian golden hamsters

    OpenAIRE

    Chau, David T; Gulick, Danielle; Xie, Haiyi; Dawson, Ree; Green, Alan I.

    2009-01-01

    Alcohol use disorder is common in patients with schizophrenia and is associated with poor clinical outcomes. Preliminary reports from our group and others suggest that the atypical antipsychotic clozapine may decrease alcohol use in these patients. We have previously shown that clozapine suppresses alcohol consumption for 9 days in Syrian golden hamsters. Here, we assessed the effects of clozapine on alcohol consumption in hamsters over a 27-day period, using a continuous access, 2-bottle (15...

  19. Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters

    OpenAIRE

    delBarco-Trillo, Javier; Johnston, Robert E.

    2012-01-01

    If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after...

  20. Experience-Independent Development of the Hamster Circadian Visual System

    OpenAIRE

    Kampf-Lassin, August; Wei, Jenny; Galang, Jerome; Prendergast, Brian J

    2011-01-01

    Experience-dependent functional plasticity is a hallmark of the primary visual system, but it is not known if analogous mechanisms govern development of the circadian visual system. Here we investigated molecular, anatomical, and behavioral consequences of complete monocular light deprivation during extended intervals of postnatal development in Syrian hamsters. Hamsters were raised in constant darkness and opaque contact lenses were applied shortly after eye opening and prior to the introduc...

  1. Cultivation of hamster bone marrow haematopoietic stem and progenitor cells

    OpenAIRE

    Kovačević-Filipović Milica; Okić Ivana; Petrićević Tanja; Mojsilović S.; Krstić Aleksandra; Jovčić Gordana; Bugarski Diana; Milenković P.; Petakov Marijana; Radovanović Anita; Božić Tatjana; Ivanović Z.

    2010-01-01

    Hamster, a hibernating animal, is an important experimental model in research on the influence of hypothermia on different physiological processes. A simple procedure for cultivation and identification of hamster hematopoetic stem cells (HSC) and hematopoetic progenitor cells (HPC) is a premise for a successful investigation upon hypothermia effects on hematopoiesis. The aim of this work was to evaluate the utilization of commercially available methylcellulose media (MC) and recombinant mouse...

  2. Fasting-induced daily torpor in desert hamsters (Phodopus roborovskii).

    Science.gov (United States)

    Chi, Qing-Sheng; Wan, Xin-Rong; Geiser, Fritz; Wang, De-Hua

    2016-09-01

    Daily torpor is frequently expressed in small rodents when facing energetically unfavorable ambient conditions. Desert hamsters (Phodopus roborovskii, ~20g) appear to be an exception as they have been described as homeothermic. However, we hypothesized that they can use torpor because we observed reversible decreases of body temperature (Tb) in fasted hamsters. To test this hypothesis we (i) randomly exposed fasted summer-acclimated hamsters to ambient temperatures (Tas) ranging from 5 to 30°C or (ii) supplied them with different rations of food at Ta 23°C. All desert hamsters showed heterothermy with the lowest mean Tb of 31.4±1.9°C (minimum, 29.0°C) and 31.8±2.0°C (minimum, 29.0°C) when fasted at Ta of 23°C and 19°C, respectively. Below Ta 19°C, the lowest Tb and metabolic rate increased and the proportion of hamsters using heterothermy declined. At Ta 5°C, nearly all hamsters remained normothermic by increasing heat production, suggesting that the heterothermy only occurs in moderately cold conditions, perhaps to avoid freezing at extremely low Tas. During heterothermy, Tbs below 31°C with metabolic rates below 25% of those during normothermia were detected in four individuals at Ta of 19°C and 23°C. Consequently, by definition, our observations confirm that fasted desert hamsters are capable of shallow daily torpor. The negative correlation between the lowest Tbs and amount of food supply shows that heterothermy was mainly triggered by food shortage. Our data indicate that summer-acclimated desert hamsters can express fasting-induced shallow daily torpor, which may be of significance for energy conservation and survival in the wild. PMID:27215346

  3. Golden hamsters are nocturnal in captivity but diurnal in nature

    OpenAIRE

    GATTERMANN, Rolf; Johnston, Robert E; Yigit, Nuri; Fritzsche, Peter; Larimer, Samantha; Özkurt, Sakir; Neumann, Karsten; Song, Zhimin; Colak, Ercüment; Johnston, Joan; McPhee, M. Elsbeth

    2008-01-01

    Daily activity rhythms are nearly universal among animals and their specific pattern is an adaptation of each species to its ecological niche. Owing to the extremely consistent nocturnal patterns of activity shown by golden hamsters (Mesocricetus auratus) in the laboratory, this species is a prime model for studying the mechanisms controlling circadian rhythms. In contrast to laboratory data, we discovered that female hamsters in the wild were almost exclusively diurnal. These results raise m...

  4. Fluoxetine does not prevent interspecific mating between two hamster species

    OpenAIRE

    delBarco-Trillo, Javier; Johnston, Robert E.

    2010-01-01

    In a recent study we showed that female Syrian hamsters (Mesocricetus auratus) from a laboratory stock readily mated with male Turkish hamsters (M. brandti). We hypothesized that captivity and/or unconscious selection of the most receptive females by researchers or animal caretakers results in heightened female sexual receptivity and reduces the tendency to reject heterospecific males. To test this hypothesis, we decided to decrease female receptivity by injection of fluoxetine, which increas...

  5. Seasonal aspects of sleep in the Djungarian hamster

    OpenAIRE

    Deboer Tom; Palchykova Svitlana; Tobler Irene

    2003-01-01

    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 th...

  6. 中国人群FGFR2基因多态性与乳腺癌易感相关性研究的Meta分析%Fibroblast growth factor receptor 2 polymorphism and susceptibility to breast cancer in Chinese population:a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    邱秀娟; 成芳; 高俊

    2015-01-01

    OBJECTIVE To evaluate the association between the fibroblast growth factor receptor 2 (FGFR2) gene polymorphism (rs2981582,rs1219648,rs2420946) and the breast cancer risk in the Chinese populations.METHODS All studies published up to June 2014 on the association between three functional polymorphisms (rs2981582,rs1219648,rs2420946) in the promoter of FGFR2 gene and susceptibility to breast cancer in Chinese population were collected by searching PubMed,Embase,Cochrane library,CNKI,VIP,Wanfang and CBD database.The data were screened according to the inclusion and exclusion criteria,and extracted,and the quality of included studies was evaluated.The pooled odds ratios (OR) with 95 % confidence intervals (95 % CI) were calculated using Stata 12.0 software.Publication bias and sensitivity analysis were also assessed.RESULTS A total of 18 case-control studies involving 14568 cases and 12864 controls were included in the Meta-analysis.The FGFR2 rs2981582,rs1219648,rs2420946 polymorphisms were significantly associated with breast cancer risk susceptibility among Chinese populations.The subgroup analysis by region revealed that significant risks were found in southern and northern China populations for rs2981582 T allele(southern:OR=1.13,95 %CI:1.06-1.22,P =0.001 ; northern:OR =1.26,95% CI..1.06-1.49,P =0.008).Significant risks were found in southern China populations for rs2420946 T allele (OR=1.15,95 % CI:1.08-1.23,P<0.05),but not in northern China populations (OR=1.03,95 % CI:0.87-1.22,P =0.695).Significant risks were found in southern and northern China populations for rs1219648 G allele(southern:OR=1.19,95%CI:1.10-1.28,P<0.05; northern:OR=1.17,95%CI:1.00-1.37,P=0.05).CONCLUSION The FGFR2 rs2981582,rs1219648,rs2420946 polymorphisms are significantly associated with breast cancer risk susceptibility among Chinese populations.%目的 系统评估成纤维细胞生长因子受体2(fibroblast growth factor receptor 2,FGFR2)基因内含子的3

  7. Adaptation of the interspersed repetitive sequence polymerase chain reaction to the isolation of mouse DNA probes from somatic cell hybrids on a hamster background

    International Nuclear Information System (INIS)

    A strategy for the rapid isolation of DNA probes from radiation-fusion Chinese hamster cell hybrids containing overlapping portions of the murine X chromosome based on the interspersed repetitive sequence polymerase chain reaction (IRS-PCR) previously used with human somatic cell hybrids has been developed. This specific amplification of mouse DNA on a hamster background depends on the use of primers directed to the B2 short interspersed repeat element family and the R repeat, from the long interspersed repeat element family, L1. Two sets of amplification conditions, which gave specific amplification of mouse DNA from either a mouse X-monochromosomal hybrid or irradiation-fusion hybrids having reduced X content, were defined. The mouse X-only chromosome hybrid yielded approximately 20 discrete reproducible bands, while the irradiation-fusion hybrids yielded between 1 and 10 discrete products. Comparison of different irradiation-fusion hybrids has allowed the definition of both specific and shared products corresponding to different regions within the overlapping X-chromosome fragments present within these hybrids. Use of such hybrids and the IRS-PCR technique has allowed the isolation of probes corresponding to the central region of the mouse X chromosome that contains the X-inactivation center. The method should be widely applicable to the isolation of mouse DNA sequences from mouse hybrid cell lines on either human or Chinese hamster backgrounds

  8. Copulatory and agonistic behavior in Syrian hamsters following social defeat.

    Science.gov (United States)

    Jeffress, Elizabeth C; Huhman, Kim L

    2013-01-01

    Syrian hamsters are highly aggressive animals that reliably defend their home territory. After social defeat, however, hamsters no longer defend their home cage but instead display submissive and defensive behavior toward an intruder, a response that we have termed conditioned defeat. Plasma testosterone is significantly reduced in Syrian hamsters following repeated defeat suggesting that social defeat might also impair copulatory behavior. The present study aimed to determine whether copulatory behavior in male Syrian hamsters is suppressed following repeated social defeats and additionally whether exposure to a hormone-primed stimulus female after social defeat reduces the behavioral response to defeat. Hamsters were paired with an aggressive opponent for one or nine defeats using a resident-intruder model, while controls were placed into the empty cage of a resident aggressor. On the day after the last treatment, half of the hamsters were paired with a receptive female for 10 min. There were no significant differences in the copulatory behavior of defeated versus non-defeated hamsters, and the opportunity to copulate had no effect on subsequent conditioned defeat testing, as defeated animals displayed significantly more submissive behavior than did non-defeated animals. The current data suggest that conditioned defeat is not necessarily a maladaptive response to social stress, at least in terms of reproductive behavior, but may instead represent a viable behavioral strategy adopted by losing animals following social defeat. Further, these data indicate that conditioned defeat is relatively persistent and stable, as the opportunity to copulate does not reduce the subsequent display of submissive behavior. PMID:23382023

  9. Massive Ca-induced Membrane Fusion and Phospholipid Changes Triggered by Reverse Na/Ca Exchange in BHK Fibroblasts

    OpenAIRE

    Yaradanakul, Alp; Wang, Tzu-Ming; Lariccia, Vincenzo; Lin, Mei-Jung; Shen, Chengcheng; Liu, Xinran; Hilgemann, Donald W.

    2008-01-01

    Baby hamster kidney (BHK) fibroblasts increase their cell capacitance by 25–100% within 5 s upon activating maximal Ca influx via constitutively expressed cardiac Na/Ca exchangers (NCX1). Free Ca, measured with fluo-5N, transiently exceeds 0.2 mM with total Ca influx amounting to ∼5 mmol/liter cell volume. Capacitance responses are half-maximal when NCX1 promotes a free cytoplasmic Ca of 0.12 mM (Hill coefficient ≈ 2). Capacitance can return to baseline in 1–3 min, and responses can be repeat...

  10. Malignancy of transplanted hamster lung lesions induced by inhaled 239PuO2

    International Nuclear Information System (INIS)

    Selected sites from the lungs of hamsters that had inhaled 239PuO2 aerosol were serially transplanted into the cheek pouches of recipient hamsters. Up to 13 mo postexposure, no evidence of malignancy has appeared

  11. The hamster flank organ model: Is it relevant to man

    International Nuclear Information System (INIS)

    The critical role that androgens play in the etiology of acne has led to a search for topically active antiandrogens and the frequent use of the flank organ of the golden Syrian hamster as an animal model. 17-alpha-propyltestosterone (17-PT) has been identified as having potent antiandrogenic activity in the hamster model, and this report describes its clinical evaluation. Two double-blind placebo controlled studies comparing 4% 17-PT in 80% alcohol versus vehicle alone were conducted. One study examined 17-PT sebosuppressive activity in 20 subjects. The second study examined its efficacy in 44 subjects having mild to moderate acne. A third study measured in vitro percutaneous absorption of 17-PT through hamster flank and monkey skin, and human face skin in-vivo, using radioactive drug. 17-PT was found to be ineffective in reducing either the sebum excretion rate or the number of inflammatory acne lesions. Failure of 17-PT to show clinical activity was not a result of poor percutaneous absorption. Total absorption in man was 7.7% of the dose and only 1.0% in the hamster. The sebaceous gland of hamster flank organ is apparently more sensitive to antiandrogens than the human sebaceous gland

  12. Microprobe analysis of human fibroblasts

    International Nuclear Information System (INIS)

    The Melbourne Proton Microprobe has been used to study the copper content in human skin fibroblast cells derived from patients with the genetic disease Menkes Syndrome. Both normal and diseased cells have been studied to investigate any elemental differences occurring between the two cell types. This paper details the preparatory techniques necessary for individual cell analysis and presents the elemental information with a new three dimensional contour mapping technique. These maps are used to highlight elemental differences between normal and mutant fibroblasts. The work also confirms the expected copper excess found in the Menkes cell and indicates that the microprobe can be used for rapid identification of a Menkes carrier

  13. Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters

    OpenAIRE

    Gulick, Danielle; Green, Alan I.

    2010-01-01

    The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster’s alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution is concurrently available and caloric intake in the hamster before, during, and after exposure t...

  14. 外用重组牛碱性成纤维细胞生长因子结合中药沐足治疗糖尿病足难愈创口临床研究%Clinical research of recombinant bovine basic fibroblast growth factor for external use combined with traditional Chinese medicine foot bath in treatment of diabetic foot with badly healing wound

    Institute of Scientific and Technical Information of China (English)

    徐继周

    2015-01-01

    目的:探讨外用重组牛碱性成纤维细胞生长因子结合中药沐足治疗糖尿病足难愈创口的临床疗效。方法选取2012年8月~2014年1月我院糖尿病足部溃疡患者60例,随机分为观察组和对照组,各30例。观察组给予中药沐足、l% Ag-SD霜联合重组牛碱性成纤维细胞生长因子局部外用,而对照组仅局部外用l% Ag-SD霜。观察及比较两组患者治疗后临床疗效、创面愈合时间、住院时间及不良反应情况。结果观察组患者总有效率明显高于对照组,创面愈合时间和住院时间明显短于对照组(P<0.05),且两组均未见不良反应。结论外用重组牛碱性成纤维细胞生长因子联合中药沐足治疗糖尿病足难愈创口患者疗效安全、有效,能促进创面愈合,缩短住院时间。%Objective To investigate the clinical efficacy of recombinant bovine basic fibroblast growth factor for external use combined with traditional Chinese medicine foot bath in treatment of diabetic foot with badly healing wound.Methods 60 patients of diabetic foot ulcer from August 2012 to January 2014 in our hospital were chosed and randomly divided into the observation group and control group,each group in 30 cases.The observation group was given traditional Chinese medicine foot bath,l% Ag-SD cream combined with recombinant bovine basic fibroblast growth factor for external use,while the control group was given only l% Ag-SD cream for external use.The clinical efficacy,wound healing time,hospitalization time and adverse reactions of patients in two groups after treatment were observed and compared.Results The total effective rate of patients in the observation group was significantly better than that in the control group,wound healing time and hospitalization time were significantly shorter than those in the control group (P<0.05),and no adverse reactions happened in the two groups.ConclusionRecombinant bovine basic fibroblast growth

  15. 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.

  16. Asbestos cement dust inhalation by hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Wehner, A.P.; Dagle, G.E.; Cannon, W.C.; Buschbom, R.L. (Pacific Northwest Laboratories, Richland, WA (USA))

    1978-12-01

    Two groups of 96 male Syrian golden hamsters were exposed to respirable asbestos cement aerosol at concentrations of approximately 1 and approximately 10 micrograms/liter, respectively, 3 hours/day, 5 days/week. Average fiber counts ranged from 5 to about 120 fibers/cm3. Each group was randomly divided into six subgroups of 16 animals. The first subgroup was sacrificed after 3 months of exposure, the second after 6 months, and the third after 15 months. The fourth subgroup was withdrawn from exposure after 3 months, observed for an additional 3 months, and then sacrificed. The fifth and sixth subgroups were withdrawn after 3 and 6 months of exposure, respectively, and maintained for observation up to the 15-month exposure point of the third subgroup at which time all surviving animals were sacrificed. All other experimental procedures were similar to those delineated in a previous publication describing the development of an animal model, techniques, and an exposure system for asbestos cement dust inhalation. The asbestos cement exposures had no significant effect on body weight and mortality of the animals. Higher aerosol concentration and longer exposure times increased the number of macrophages and ferruginous bodies found in the lungs of the exposed animals. Recovery periods had no effect on the incidence of macrophages and ferruginous bodies. The incidence of very slight to slight fibrosis in the animals sacrificed after 15 months of exposure shows a significant (P less than 0.01) trend when the untreated control group and the 1 and 10 microgram/liter dose level groups are compared, indicating a dose-response relationship. Development of minimal fibrosis continued in animals withdrawn from exposure. No primary carcinomas of the lung and respiratory tract and no mesotheliomas were found.

  17. Hamster thecal cells express muscle characteristics

    International Nuclear Information System (INIS)

    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

  18. Autonomic nervous dysfunction in hamsters infected with West Nile virus.

    Directory of Open Access Journals (Sweden)

    Hong Wang

    Full Text Available Clinical studies and case reports clearly document that West Nile virus (WNV can cause respiratory and gastrointestinal (GI complications. Other functions controlled by the autonomic nervous system may also be directly affected by WNV, such as bladder and cardiac functions. To investigate how WNV can cause autonomic dysfunctions, we focused on the cardiac and GI dysfunctions of rodents infected with WNV. Infected hamsters had distension of the stomach and intestines at day 9 after viral challenge. GI motility was detected by a dye retention assay; phenol red dye was retained more in the stomachs of infected hamsters as compared to sham-infected hamsters. The amplitudes of electromygraphs (EMGs of intestinal muscles were significantly reduced. Myenteric neurons that innervate the intestines, in addition to neurons in the brain stem, were identified to be infected with WNV. These data suggest that infected neurons controlling autonomic function were the cause of GI dysfunction in WNV-infected hamsters. Using radiotelemetry to record electrocardiograms and to measure heart rate variability (HRV, a well-accepted readout for autonomic function, we determined that HRV and autonomic function were suppressed in WNV-infected hamsters. Cardiac histopathology was observed at day 9 only in the right atrium, which was coincident with WNV staining. A subset of WNV infected cells was identified among cells with hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4 as a marker for cells in the sinoatrial (SA and atrioventricular (AV nodes. The unique contribution of this study is the discovery that WNV infection of hamsters can lead to autonomic dysfunction as determined by reduced HRV and reduced EMG amplitudes of the GI tract. These data may model autonomic dysfunction of the human West Nile neurological disease.

  19. Use of CB hamsters in the study of Treponema pertenue.

    Science.gov (United States)

    Schell, R F; Le Frock, J L; Babu, J P; Chan, J K

    1979-10-01

    The CB/Ss LAK strain of inbred hamster was used as a model for studies of infection with Treponema pertenue and of acquired resistance to it. When infected, this strain developed cutaneous lesions which lasted for six to seven months, even in the presence of peak titres of antitreponemal antibody. The rate of appearance and resolution of these lesions varied with the size of the inoculum. The infected hamsters' inguinal lymph nodes increased significantly in weight and teemed with treponemes for several weeks. Animals infected for eight or 10 weeks obtained quick resolution of their lesions by treatment with penicillin and were thereafter resistant to reinfection. PMID:509189

  20. Inhibitory effects of Zengshengping fractions on DMBA-induced buccal pouch carcinogenesis in hamsters

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-bing; SUN Zheng; CHEN Xiao-xin; WU Hong-ru; ZHANG Xin-yan

    2012-01-01

    Background Zengshengping (ZSP) tablets had inhibitory effects on oral precancerous lesions by reducing the incidence of oral cancer.However,the severe liver toxicity caused by systemic administration of ZSP limits the long-term use of this anti-cancer drug.The purpose of this study was to evaluate the tumor inhibitory effects due to the topical application of extracts from ZSP,a Chinese herbal drug,on 7,12-dimethlbenz(a)anthracene (DMBA) induced oral tumors in hamsters.The study also investigated the anti-cancer mechanisms of the ZSP extracts on oral carcinogenesis.Methods DMBA (0.5%) was applied topically to the buccal pouches of Syrian golden hamsters (6-8 weeks old) three times per week for six weeks in order to induce the development of oral tumors.Different fractions of ZSP were either applied topically to the oral tumor lesions or fed orally at varying dosages to animals with oral tumors for 18 weeks.Tumor volume was measured by histopathological examination.Tumor cell proliferation was evaluated by counting BrdU labeled cells and by Western blotting for mitogen-activated protein kinase (MAPK) protein levels.The protein levels of apoptosis marker Caspase-3 and regulator Bcl-2 protein were also measured by Western blotting.Results Topical application of DMBA to the left pouch of hamsters induced oral tumor formation.Animals treated with DMBA showed a loss in body weight while animals treated with ZSP maintained normal body weights.Both the ZSP n-butanol fraction and water fraction significantly reduced tumor volume by 32.6% (P <0.01) and 22.9% (P <0.01)respectively.Topical application of ZSP also markedly decreased the BrdU-positive cell numbers in oral tumor lesions and reduced the expression level of MAPK.In addition,ZSP promoted tumor cell apoptosis by increasing Caspase-3 expression but decreasing Bcl-2 protein production.Conclusion The n-butanol and water fractions of ZSP are effective at inhibiting tumor cell proliferation and stimulating

  1. Influence of dose rate on the transformation of Syrian hamster embryo cells by fission-spectrum neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.A.; Sedita, B.A.; Hill, C.K.; Elkind, M.M.

    1988-01-01

    Several explanations for this neutron dose-rate effect have been proposed, but further investigation is necessary to determine the mechanisms involved. In all cell transformation studies to date the immortalized, aneuploid 10T1/2 cell-line has been used. These cells may be premalignant; thus their response characteristics and, in particular, the nature of the transformation event, might differ from that in a normal, fibroblast cell. One reason for the present study was to determine whether the low-dose-rate effect of fission neutrons could be demonstrated in normal cells. If so, a normal cell system, which would more closely resemble a normal in vivo system, could be used for mechanistic studies. We chose Syrian hamster embryo (SHE) fibroblasts which are normal, diploid cells with a limited life span in culture. Upon exposure to low doses of ionizing radiation, the fraction of the cells that are transformed can be identified in a standard 8--10 day colony assay by examining their clonal morphology. Transformed cells form colonies with a dense, criss-crossed or piled-up structure. A high percentage of the transformed colonies can be further propagated and will acquire additional neoplastic characteristics; i.e., anchorage independence, immortality, altered proteolytic activity, karyotype alterations, and finally, tumorigenicity.

  2. Influence of dose rate on the transformation of Syrian hamster embryo cells by fission-spectrum neutrons

    International Nuclear Information System (INIS)

    Several explanations for this neutron dose-rate effect have been proposed, but further investigation is necessary to determine the mechanisms involved. In all cell transformation studies to date the immortalized, aneuploid 10T1/2 cell-line has been used. These cells may be premalignant; thus their response characteristics and, in particular, the nature of the transformation event, might differ from that in a normal, fibroblast cell. One reason for the present study was to determine whether the low-dose-rate effect of fission neutrons could be demonstrated in normal cells. If so, a normal cell system, which would more closely resemble a normal in vivo system, could be used for mechanistic studies. We chose Syrian hamster embryo (SHE) fibroblasts which are normal, diploid cells with a limited life span in culture. Upon exposure to low doses of ionizing radiation, the fraction of the cells that are transformed can be identified in a standard 8--10 day colony assay by examining their clonal morphology. Transformed cells form colonies with a dense, criss-crossed or piled-up structure. A high percentage of the transformed colonies can be further propagated and will acquire additional neoplastic characteristics; i.e., anchorage independence, immortality, altered proteolytic activity, karyotype alterations, and finally, tumorigenicity

  3. 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.

  4. Matrix population modelling of the Common hamster life history

    Czech Academy of Sciences Publication Activity Database

    Damugi, I. E. D.; Petrová, I.; Bendová, M.; Losík, J.; Tkadlec, Emil

    Brno: Ústav biologie obratlovců AV ČR, 2016 - (Bryja, J.; Sedláček, F.; Fuchs, R.). s. 52 ISBN 978-80-87189-20-7. [Zoologické dny. 11.02.2016-12.02.2016, České Budějovice] Institutional support: RVO:68081766 Keywords : common hamster Subject RIV: EG - Zoology

  5. DOSE RESPONSE OF ELASTASE-INDUCED EMPHYSEMA IN HAMSTERS

    Science.gov (United States)

    Elastase-induced emhysema in hamsters was studied using pulmonary function tests in an effort to develop techniques for determining the effects of air pollutants on the progression of this disease. It appears that as little as 6 units of elastase produces mild emphysema in hamste...

  6. 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.

  7. Effects of pegylated hamster red blood cells on microcirculation.

    Science.gov (United States)

    Chen, Peter C Y; Huang, Wei; Stassinopoulos, Adonis; Cheung, Anthony T W

    2008-01-01

    The objective of this study was to examine the effects of polyethylene glycol (PEG) treated red blood cells (RBCs) on the microcirculation in a hamster back skin window chamber model. Donor hamster RBCs were PEGylated through an incubation with an activated PEG solution, washed, resuspended, and infused through a 10% volume top loading procedure into the carotid artery in an awake Syrian Golden hamster. Eight hamster groups were treated with activated PEG different sizes and concentrations: 0.05 mM-5 kDa PEG, 0.5 mM-5 kDa PEG, 1.1 mM-5 kDa PEG, 2.2 mM-5 kDa PEG, 22 mM-5 kDa PEG, 0.05 mM-20 kDa PEG, 0.5 mM-20 kDa PEG, and 5 mM-20 kDa PEG. Non-treated RBCs were used as control. The microvascular bed under observation was videotaped 30 min before the infusion and followed for 30 min post infusion. The diameter of individual blood vessels and blood flow velocities in selected vessels was measured. Hematocrit and hemoglobin concentration were recorded before infusion and at the end of experiment. Tissue pO(2) was also monitored. Results showed the hamsters tolerated the PEGylated RBCs without apparent ill effects. No significant changes were recorded for the hematocrit, the hemoglobin concentration, the blood vessel diameters, blood flow velocities, and the interstitial partial oxygen pressure (pO(2)) before, during, and after the injections of PEG-RBCs (P > 0.05). Unlike most hemoglobin-based oxygen carrying compounds, which can cause vasoconstriction, the PEGylated RBCs did not produce any measurable vasoactivity. Together with the absence of rouleaux formation and the fact that PEG molecules can mask the surface antigens on RBCs, PEGylation appeared promising as a circulation enhancement treatment. PMID:18649167

  8. Berberine regulates proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts via AMPK-mTOR-p70S6K signaling pathway

    OpenAIRE

    Ai, Fen; Chen, Manhua; Yu, Bo; Yang, Yang; Xu, Guizhong; Gui, Feng; Liu, Zhenxing; Bai, Xiangyan; Chen, Zhen

    2015-01-01

    Objective: The traditional Chinese medicinal berberine has long been used to treat cardiovascular diseases; however, the mechanism underlying its effects remains unclear. Here, this study would to investigate the effects of berberine on proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts. Methods: We assessed proliferation, collagen synthesis and cytokine secretion in cardiac fibroblasts subjected to angiotensin II (Ang II) subsequent to the consumption of berberin...

  9. Characterization of a tachykinin peptide NK2 receptor transfected into murine fibroblast B82 cells

    International Nuclear Information System (INIS)

    Membranes isolated from a murine fibroblast B82 cell line (SKLKB82 number-sign 3) transfected with the bovine stomach cDNA pSKR56S exhibited binding of [His(125I)1]neurokinin A (125I-NKA) to a single population of sites with a Bmax of 147 fmol/mg of protein and a Kd of 0.59 nM. The ligand binding in SKLKB82 number-sign 3 cells was reversible. Thus, SKLKB82 number-sign 3 cells have been transfected with NK2 receptors that have become associated with an endogenous guanine nucleotide-binding protein. In comparison with membranes from the hamster urinary bladder, a tissue enriched in NK2 receptors, NK2 receptor antagonists displayed markedly different potencies, either more or less potent, in inhibiting specific binding in membranes of the transfected cells. Furthermore, inhibition of 125I-NKA binding by nucleotide analogues was markedly different in SKLKB82 number-sign 3 cells compared with hamster bladder tissue. The different binding profile in the cells is not due to an artefact introduced during cDNA transfection because a similar profile was also observed in bovine stomach membranes. These results may indicate the existence of two distinct NK2 receptors

  10. Fibroblast growth factors as tissue repair and regeneration therapeutics.

    Science.gov (United States)

    Nunes, Quentin M; Li, Yong; Sun, Changye; Kinnunen, Tarja K; Fernig, David G

    2016-01-01

    Cell communication is central to the integration of cell function required for the development and homeostasis of multicellular animals. Proteins are an important currency of cell communication, acting locally (auto-, juxta-, or paracrine) or systemically (endocrine). The fibroblast growth factor (FGF) family contributes to the regulation of virtually all aspects of development and organogenesis, and after birth to tissue maintenance, as well as particular aspects of organism physiology. In the West, oncology has been the focus of translation of FGF research, whereas in China and to an extent Japan a major focus has been to use FGFs in repair and regeneration settings. These differences have their roots in research history and aims. The Chinese drive into biotechnology and the delivery of engineered clinical grade FGFs by a major Chinese research group were important enablers in this respect. The Chinese language clinical literature is not widely accessible. To put this into context, we provide the essential molecular and functional background to the FGF communication system covering FGF ligands, the heparan sulfate and Klotho co-receptors and FGF receptor (FGFR) tyrosine kinases. We then summarise a selection of clinical reports that demonstrate the efficacy of engineered recombinant FGF ligands in treating a wide range of conditions that require tissue repair/regeneration. Alongside, the functional reasons why application of exogenous FGF ligands does not lead to cancers are described. Together, this highlights that the FGF ligands represent a major opportunity for clinical translation that has been largely overlooked in the West. PMID:26793421

  11. Competitive dose-modification between ascorbate and misonidazole in human and hamster cells: effects of glutathione depletion

    International Nuclear Information System (INIS)

    Depletion of glutathione by pretreatment with buthionine sulphoximine greatly enhances the radiosensitizing efficiency of misonidazole in mammalian cells in vitro, but a similar effect has not yet been observed in vivo. In thiol-depleted V79 Chinese hamster cells and human HT1080 fibrosarcoma cells, physiological concentrations of ascorbate greatly reduce misonidazole radiosensitization, although there is little effect of ascorbate on misonidazole sensitization in untreated cells. The effect of ascorbate on misonidazole radiosensitization is not markedly dependent on the extracellular concentration of ascorbate; this may be explained by the non-equilibrium uptake of ascorbate at different extracellular concentrations. Failure to obtain a large enhancement of misonidazole radiosensitization as a result of buthionine sulphoximine treatment in vivo may be due, in part at least, to the presence of ascorbate. (author)

  12. 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…

  13. 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.

  14. Heat and cold acclimation in helium-cold hypothermia in the hamster.

    Science.gov (United States)

    Musacchia, X. J.

    1972-01-01

    A study was made of the effects of acclimation of hamsters to high (34-35 C) and low (4-5 C) temperatures for periods up to 6 weeks on the induction of hypothermia in hamsters. Hypothermia was achieved by exposing hamsters to a helox mixture of 80% helium and 20% oxygen at 0 C. Hypothermic induction was most rapid (2-3 hr) in heat-acclimated hamsters and slowest (6-12 hr) in cold-acclimated hamsters. The induction period was intermediate (5-8 hr) in room temperature nonacclimated animals (controls). Survival time in hypothermia was relatable to previous temperature acclimations. The hypothesis that thermogenesis in cold-acclimated hamsters would accentuate resistance to induction of hypothermia was substantiated.

  15. TELOMERASE ACTIVITY DURING 7, 12-DIMETHYLBENZ [a] ANTHRACENE-INDUCED HAMSTER BUCCAL POUCH CARCINOGENESIS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate the roles of telomerase activity (TA) in relation to hamster buccal pouch tumor progression. Methods: male hamster were treated three times weekly with 0.5% of 7, 12-dimethyl- benzanthracene (DMBA) over a 15 weeks experimental period. Hamsters were sacrificed at 3, 6, 9, 12 and 15 weeks after treatment. Telomerase activity of hamster buccal pouch tissue were measured along with the analyses of the formation of DMBA-induced hamster buccal pouch tumors. Results: DMBA-induced squamous cell carcinomas were found at the 6th week after dosing. Telomerase activity elevation began at the 3rd week and was increasing to a plateau at the 12th week. Conclusion: Our results show that telomerase activity in the target tissue may be detected at the early stage of the DMBA-induced hamster buccal pouch tumor formation and suggests that telomerase activity may be used as a biomarker for an early clinical detection of buccal pouch cancer.

  16. Antibody-Mediated Inhibition of the FGFR1c Isoform Induces a Catabolic Lean State in Siberian Hamsters.

    Science.gov (United States)

    Samms, Ricardo J; Lewis, Jo E; Lory, Alex; Fowler, Maxine J; Cooper, Scott; Warner, Amy; Emmerson, Paul; Adams, Andrew C; Luckett, Jeni C; Perkins, Alan C; Wilson, Dana; Barrett, Perry; Tsintzas, Kostas; Ebling, Francis J P

    2015-11-16

    Hypothalamic tanycytes are considered to function as sensors of peripheral metabolism. To facilitate this role, they express a wide range of receptors, including fibroblast growth factor receptor 1 (FGFR1). Using a monoclonal antibody (IMC-H7) that selectively antagonizes the FGFR1c isoform, we investigated possible actions of FGFR1c in a natural animal model of adiposity, the Siberian hamster. Infusion of IMC-H7 into the third ventricle suppressed appetite and increased energy expenditure. Likewise, peripheral treatment with IMC-H7 decreased appetite and body weight and increased energy expenditure and fat oxidation. A greater reduction in body weight and caloric intake was observed in response to IMC-H7 during the long-day fat state as compared to the short-day lean state. This enhanced response to IMC-H7 was also observed in calorically restricted hamsters maintained in long days, suggesting that it is the central photoperiodic state rather than the peripheral adiposity that determines the response to FGFR1c antagonism. Hypothalamic thyroid hormone availability is controlled by deiodinase enzymes (DIO2 and DIO3) expressed in tanycytes and is the key regulator of seasonal cycles of energy balance. Therefore, we determined the effect of IMC-H7 on hypothalamic expression of these deiodinase enzymes. The reductions in food intake and body weight were always associated with decreased expression of DIO2 in the hypothalamic ependymal cell layer containing tanycytes. These data provide further support for the notion the tanycytes are an important component of the mechanism by which the hypothalamus integrates central and peripheral signals to regulate energy intake and expenditure. PMID:26549257

  17. 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.

  18. Photoperiodic regulation of adrenal hormone secretion and aggression in female Syrian hamsters

    OpenAIRE

    Gutzler, Stephanie J.; Karom, Mary; Erwin, W. Daniel; ALBERS, H. Elliott

    2009-01-01

    Seasonal changes in the length of the daily photoperiod induce significant changes in social behavior. Hamsters housed in winter-like short photoperiods (SP) can express significantly higher levels of aggression than hamsters housed in long photoperiods (LP) that mimic summer. The mechanisms responsible for increasing aggressiveness in SP-exposed female hamsters are not well understood but may involve seasonal changes in the endocrine system. In experiment 1, the effects of SP exposure on the...

  19. Acquired resistance of hamsters to challenge with homologous and heterologous virulent treponemes.

    OpenAIRE

    Schell, R F; Azadegan, A A; Nitskansky, S G; LeFrock, J L

    1982-01-01

    Hamsters infected with Treponema pallidum Nichols (venereal syphilis), T. pallidum Bosnia A (endemic syphilis), or T. pertenue (frambesia, or yaws) developed substantial resistance to homologous reinfection. Hamsters infected for 10 weeks developed no lesions, and their lymph nodes contained fewer treponemes after reinfection with the same strain. The degree of cross-resistance among the treponemes correlated well with pathological changes occurring in infected hamsters and with the persisten...

  20. Oral implantation of Bacteroides asaccharolyticus and Eikenella corrodens in conventional hamsters.

    OpenAIRE

    Nagahata, T; Kiyoshige, T; Tomono, S; Abe, R; Sasaki, S.; Takazoe, I

    1982-01-01

    Oral implantation of Bacteroides asaccharolyticus 381-R' and Eikenella corrodens 1073S-R, which are highly resistant to streptomycin, was examined in conventional hamsters. The hamsters' first molars were ligatured with cotton threads preimmersed in bacterial suspensions. Bacterial inoculation was performed daily for 1 week, followed by a single weekly inoculation for 7 more weeks. Hamsters were fed Keyes' diet no. 2000 or ordinary powdered diet. Bacterial recovery, gingival histological chan...

  1. 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.

  2. Inhibition of caries in hamsters treated with staphylococcin 1580.

    OpenAIRE

    Fitzgerald, R J; Morhart, R E; Marquez, C; Adams, B. O.

    1986-01-01

    Littermate hamsters were infected orally with cariogenic Streptococcus mutans NS-50S and maintained on a high-sucrose diet to induce dental caries. Individual groups of animals were treated by single daily instillation of staphylococcin 1580 (100 micrograms) in the cheek pouches. Other groups were treated similarly with bacitracin (60 or 120 U) or saline. After 35 days on the caries test regimen, animals treated with staphylococcin 1580 had 49 or 60% less caries than the saline controls in tw...

  3. Autoradiographic images in the hamster cheek pouch oral cancer model

    International Nuclear Information System (INIS)

    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)

  4. Goitre and wasting induced in hamsters by hexachlorobenzene

    International Nuclear Information System (INIS)

    Male Syrian hamsters were treated with hexachlorobenzene (HCB) in their diet at levels of 100 ppm for 28 weeks, 200 ppm for 18 and 28 weeks, and 500 ppm for 6 weeks. All treatments caused at least a 2.5- to 3-fold increase in thyroid size, mainly by enlargement of some follicles. Serum thyroxine (T4) levels were unchanged, whereas levels of triiodothyronine (T3) eventually became depressed by >60%. Uptake of 131I into thyroids was induced approximately 3-fold when estimated after feeding HCB (500 ppm) for 3 or 6 weeks. Hamsters also lost weight by depletion of adipose tissue, leading to 50% mortality in longer experiments. Results were distinct from the effects of the known antithyroid agent 3-aminotriazole or amitrole (200 ppm for 28 weeks), which did not affect survival and although causing thyroid enlargement depressed serum T4 and significantly elevated T3. The effects of HCB in hamsters were also different from those in rats (500 ppm HCB for 6 weeks) in which there was only a small increase in thyroid size (1.3-fold), serum levels of T3 were only slightly depressed but T4 levels were reduced by 74%. These studies are discussed with reference to the effects of other polyhalogenated aromatic chemicals on the thyroid, serum thyroid hormone levels and lethality. (orig.)

  5. Effects of hyperthermia on the hamster immune system

    International Nuclear Information System (INIS)

    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 (410C; 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

  6. Teratogenicity and embryotoxicity of nickel carbonyl in Syrian hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Sunderman, F.W. Jr.; Shen, S.K.; Reid, M.C.; Allpass, P.R.

    1980-01-01

    Nickel carbonyl was administered to groups of pregnant hamsters by inhalation on days 4, 5, 6, 7, or 8 of gestation. The dams were killed on day 15 of gestation, and the fetuses were examined for malformations. Exposure to Ni(CO)/sub 4/ on days 4 or 5 of gestation resulted in malformation in 5.5% and 5.8% of the progeny, respectively. Progeny included 9 fetuses with cystic lungs, 7 fetuses with exencephaly, 1 fetus with exencephaly plus fused rib and 1 fetus with anophthalmia plus cleft palate. Hemorrhages into serious cavities were found. In progeny of dams exposed to Ni(CO)/sub 4/ on days 6 or 7 of gestation, there was 1 fetus with fused ribs and there were 2 fetuses with hydronephrosis. In another experiment, pregnant hamsters were exposed to inhalation of Ni(CO)/sub 4/ on day 5 of gestation; these dams were permitted to deliver their litters and to nurse their pups. There was no significant difference in the average number of live pups in the Ni(CO)/sub 4/-exposed litters compared to control litters. Neonatal mortality was increased in Ni(CO)/sub 4/-exposed litters. This study demonstrates that Ni(CO)/sub 4/ is teratogenic and embryotoxic in Syrian hamsters.

  7. Suppression of Clostridium difficile by Normal Hamster Cecal Flora and Prevention of Antibiotic-Associated Cecitis

    OpenAIRE

    Wilson, Kenneth H.; Silva, Joseph; Fekety, F. Robert

    1981-01-01

    Administration of normal cecal homogenates decreased numbers of viable Clostridium difficile and prevented cecitis in antibiotic-challenged hamsters. Cecal anaerobes appeared to suppress C. difficile.

  8. DNA (deoxyribonucleic acid) synthesis following microinjection of heterologous sperm and somatic cell nuclei into hamster oocytes

    International Nuclear Information System (INIS)

    The authors investigated the ability of the hamster oocyte to initiate DNA synthesis in nuclei differing in basic protein content. DNA synthesis was studied by autoradiography in oocytes that had been incubated in 3H-thymidine after being parthenogenetically activated by sham microinjection, or microinjected with hamster, mouse, rabbit, or fish sperm nuclei, or hamster hepatocyte nuclei. Within 6 hr of sham or nucleus microinjection, nuclei of each type underwent transformation into pronuclei and synthesized DNA. These results demonstrated that the hamster egg can access and utilize its own and each type of template provided, whether homologous or heterologous. However, pronuclei derived from hamster sperm nuclei were more likely to be synthesizing DNA at 6 hr than pronuclei derived from sperm nuclei of other species. The authors conclude that the mechanisms employed by the hamster oocyte to transform hamster sperm nuclei into pronuclei and to effect DNA synthesis in these nuclei are not specific for the hamster sperm nucleus. Nevertheless, these mechanisms apparently operate more efficiently when the hamster sperm nucleus, rather than a heterologous sperm nucleus, is present

  9. Chinese astronomy

    OpenAIRE

    Macfarlane, Alan; Cullen, Christopher

    2004-01-01

    Standing in the observatory in Beijing, Christopher Cullen discusses the nature and sophistication of Chinese astronomy in the medieval period. The political as well as the intellectual interest in astronomy is outlined.

  10. Chinese Confucianism

    OpenAIRE

    Macfarlane, Alan; Cullen, Christopher

    2004-01-01

    Confucianism has deeply influenced Chinese civilization. Christopher Cullen describes its effect on education, social structure and knowledge over the past centuries, against the backdrop of a Confucian building in Beijing.

  11. 1,25(OH)2 vitamin D3 binding sites in male sex organs of the Siberian hamster (Phodopus sungorus). An autoradiographic study

    International Nuclear Information System (INIS)

    Using autoradiography, binding sites for 1,25(OH)2 vitamin D3 are found in certain genital organs of male Siberian hamsters (Phodopus sungorus), in particular in basal epithelial cells and fibroblasts of the lamina propria of prostate glands. Scattered labeled cells are also present in the epithelium of coagulation and urethral glands. In contrast to the findings in mice, under the conditions of the experiment, 1,25(OH)2 vitamin D3 binding sites are not recognizable in other accessory sex glands and gonads. The frequency of basal epithelial cells with [3H]1,25(OH)2 vitamin D3 nuclear binding is higher in regressed dorsal prostate glands of animals living in short photoperiods. The data suggest that 1,25(OH)2 vitamin D3 may promote proliferation and differentiation in basal epithelial cells, modulated by the seasonal and functional status of the animal

  12. Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure

    Directory of Open Access Journals (Sweden)

    Thomas Gerard Hampton

    2012-05-01

    Full Text Available Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The delta-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness and heart failure. Methods to accelerate preclinical testing of gene therapy and new drugs for neuromuscular diseases are urgently needed. The purpose of this investigation was to demonstrate a rapid non-invasive screen for characterizing the autonomic nervous system imbalance in dystrophic TO-2 hamsters. Electrocardiograms were recorded non-invasively in conscious ~9-month old TO-2 hamsters (n=10 and non-myopathic F1B control hamsters (n=10. Heart rate was higher in TO-2 hamsters than controls (453 ± 12 bpm vs. 311 ± 25 bpm, P<0.01. Time domain heart rate variability, an index of parasympathetic tone, was lower in TO-2 hamsters (12.2 ± 3.7 bpm vs. 38.2 ± 6.8, P<0.05, as was the coefficient of variance of the RR interval (2.8 ± 0.9 % vs. 16.2 ± 3.4 %, P<0.05 compared to control hamsters. Power spectral analysis demonstrated reduced high frequency and low frequency contributions, indicating autonomic imbalance with increased sympathetic tone and decreased parasympathetic tone in dystrophic TO-2 hamsters. Similar observations in newborn hamsters indicate autonomic nervous dysfunction may occur quite early in life in neuromuscular diseases. Our findings of autonomic abnormalities in newborn hamsters with a mutation in the delta-sarcoglycan gene suggest approaches to correct modulation of the heart rate as prevention or therapy for muscular dystrophies.

  13. 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)...

  14. A Lethal Disease Model for Hantavirus Pulmonary Syndrome in Immunosuppressed Syrian Hamsters Infected with Sin Nombre Virus

    OpenAIRE

    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 ...

  15. CARBENDAZIM (MBC) DISRUPTS OOCYTE SPINDLE FUNCTION AND INDUCES ANEUPLOIDY IN HAMSTERS EXPOSED DURING FERTILIZATION (MEIOSIS II)

    Science.gov (United States)

    Peri-fertilization exposure to Carbendazim (MBC; a microtubule poison) induces infertility and early pregnancy loss (EPL) in hamsters. resently, both in vivo and in vitro techniques were employed to characterize the effects of MBC on cellular aspects of fertilization in hamsters....

  16. Lack of negative effects on Syrian hamsters and Mongolian gerbils housed in the same secondary enclosure.

    Science.gov (United States)

    Pritchett-Corning, Kathleen R; Gaskill, Brianna N

    2015-05-01

    In cases where different species might be housed in the same room or secondary enclosure, the Guide for the Care and Use of Laboratory Animals recommends that the animals should be behaviorally compatible and have the same health status. Syrian hamsters and Mongolian gerbils, both desert-dwelling rodents, appear to be reasonable candidates for such a combination. This study was undertaken to evaluate whether housing hamsters and gerbils in the same secondary enclosure is an acceptable practice. Weanling and breeding-age hamsters and gerbils were housed in open-topped cages in an isolator for 5 mo; the isolator also contained with nude and haired mice, which acted as sentinels. Cages housing hamsters and gerbils were rotated between species, and dirty bedding was exchanged between species in an effort to transmit microorganisms. In addition, sentinel mice housed in the isolator were supplied with dirty bedding from both hamsters and gerbils. Neither species showed clinical signs of illness, the health status of neither the hamsters nor the gerbils changed significantly, and the sentinel mice acquired only 2 infectious organisms, a Helicobacter species and Staphylococcus aureus. Both hamsters and gerbils bred successfully when housed together in the same isolator, and no infanticide or mortality was seen. Breeding performance did not differ between isolator breeding and barrier breeding. This study supports the housing of hamsters and gerbils in the same secondary enclosure. PMID:26045450

  17. Fibroblast cultures in duchenne muscular dystrophy

    International Nuclear Information System (INIS)

    Primary skin fibroblast cultures were grown from forearm pinch skin biopsies obtained from 24 patients with Duchenne muscular dystrophy (DMD) and ten normal controls matched for sex and age. The first subcultures were grown for 7 days and incubated with L-(3H)-proline for 24 hours. Intracellular collagen incoption was significantly decreased (2.2 X) and extracellular collagen incorporation significantly increased (1.8 X) in fibroblast cultures from patients with DMD by both collagenase assay and polyacrylamide gel electrophoresis. The synthesis of noncollagen proteins showed low values from the DMD fibroblast cultures. The alterations in synthesis and secretion of collagen and noncollagen proteins were characteristic only for the log phase of DMD fibroblasts. (author)

  18. Differences in motility pattern between human buccal fibroblasts and periodontal and skin fibroblasts

    DEFF Research Database (Denmark)

    Lepekhin, Eugene; Grøn, Birgitte; Berezin, Vladimir;

    2002-01-01

    -assisted microscope work-station. For evaluation of cell morphology, cell contours were recognized semiautomatically and used for determination of cell area, cell spreading and number and length of processes. We found that the cellular displacement of the buccal fibroblasts was only approximately 50% of the cellular...... displacement of periodontal and skin fibroblasts. The decreased cellular displacement of the buccal fibroblasts was found to be due to both lower cellular speed and less persistence in direction. The buccal fibroblasts also displayed smaller areas and longer processes. The differences in cellular morphology...

  19. Coupling of cytoskeleton functions for fibroblast locomotion

    DEFF Research Database (Denmark)

    Couchman, J R; Lenn, M; Rees, D A

    1985-01-01

    Using a chick cell phenotype specialised for locomotion with morphometric measurements made possible by modern instrumentation technology, we have reinvestigated motile functions in fibroblast locomotion. Quantitative analysis of rapid fluctuations in cell form and organelle distribution during l...... function of microtubules to direct the flow towards multiple foci on the leading edge, and so determine cell polarity. Such a mechanism of locomotion for fibroblasts has many features consistent with evidence for other cell types, especially amoebae and leukocytes....

  20. Modulation of Gingival Fibroblast Minocycline Accumulation by Biological Mediators

    OpenAIRE

    Walters, J.D.; Nakkula, R.J.; Maney, P.

    2005-01-01

    Gingival fibroblasts actively accumulate tetracyclines, thereby enhancing their redistribution from blood to gingiva. Since growth factors and pro-inflammatory cytokines regulate many fibroblast activities, they could potentially enhance fibroblast minocycline accumulation. To test this hypothesis, we treated gingival fibroblast monolayers for 1 or 6 hours with platelet-derived growth factor-BB (PDGF), fibroblast growth factor-2 (FGF), transforming growth factor-β1 (TGF), or tumor necrosis fa...

  1. The common properties and the heterogeneity of dermal fibroblast subpopulations.

    OpenAIRE

    Makarchuk O.I.

    2007-01-01

    Dermal fibroblasts are a dynamic and diverse population of cells whose functions in skin in many respects remain unknown. Normal adult human skin contains at least three distinct subpopulations of fibroblasts, which occupy unique niches in the dermis. Fibroblasts from each of these niches exhibit distinctive differences when cultured separately. Specific differences in fibroblast histophysiology are evident in papillary dermal fibroblasts, which reside in the superficial dermis, and reticular...

  2. Chinese Dream

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The general managers of South Korean auto giants Hyundai and Kia have high hopes for the growing Chinese auto market. Both companies went through a painstaking period as the financial crisis first roared across the globe. Jin Shan-fa, General Manager of Hyundai Motor Group

  3. Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants.

    OpenAIRE

    Persson, S A; Ahlberg, M; Berghem, L.; Könberg, E; Nordberg, G F; Bergman, F

    1988-01-01

    Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe2O3). The common weekly dose was 4.5 mg/hamster. In addition, one subgroup of hamsters was treated with oil fly ash at a weekly dose of 3.0 mg/hamster and another with coal fly ash at a weekly dose of 6.0 mg/hamster. Other groups of hamste...

  4. Mathematical Models Describing Chinese Hamster Ovary Cell Death Due to Electroporation In Vitro.

    Science.gov (United States)

    Dermol, Janja; Miklavčič, Damijan

    2015-10-01

    Electroporation is a phenomenon used in the treatment of tumors by electrochemotherapy, non-thermal ablation with irreversible electroporation, and gene therapy. When treating patients, either predefined or variable electrode geometry is used. Optimal pulse parameters are predetermined for predefined electrode geometry, while they must be calculated for each specific case for variable electrode geometry. The position and number of electrodes are also determined for each patient. It is currently assumed that above a certain experimentally determined value of electric field, all cells are permeabilized/destroyed and under it they are unaffected. In this paper, mathematical models of survival in which the probability of cell death is continuously distributed from 0 to 100 % are proposed and evaluated. Experiments were performed on cell suspensions using electrical parameters similar to standard electrochemotherapy and irreversible electroporation parameters. The proportion of surviving cells was determined using clonogenic assay for assessing the ability of a cell to grow into a colony. Various mathematical models (first-order kinetics, Hülsheger, Peleg-Fermi, Weibull, logistic, adapted Gompertz, Geeraerd) were fitted to experimental data using a non-linear least-squares method. The fit was evaluated by calculating goodness of fit and by observing the trend of values of models' parameters. The most appropriate models of cell survival as a function of treatment time were the adapted Gompertz and the Geeraerd models and, as a function of the electric field, the logistic, adapted Gompertz and Peleg-Fermi models. The next steps to be performed are validation of the most appropriate models on tissues and determination of the models' predictive power. PMID:26223863

  5. Modifications to the radiation response of Chinese hamster ovary-K1 cells by vitamin A

    International Nuclear Information System (INIS)

    Treatment of cells in vitro with Vitamin A reduced their yield and subsequent cloning efficiency. The effect was time and dose dependent. Pretreatment with low Vitamin A concentrations, protected cells which were exposed to radiation. A change in the D0 was entirely responsible for this effect. High concentrations of Vitamin A sensitised cells to radiation. A sensitising effect was also observed for cells treated with the Vitamin just prior to irradiation. The sensitisation was accompanied by a reduction in the extrapolation number of the survival curve. Close inspection of pretreatment survival curves revealed that the decrease in extrapolation number occurred even in the presence of an overall protective effect. (Auth.)

  6. Glutathione depletion, radiosensitization, and misonidazole potentiation in hypoxic Chinese hamster ovary cells by buthionine sulfoximine

    International Nuclear Information System (INIS)

    Buthionine sulfoximine (BSO) inhibits the synthesis of glutathione (GSH), the major nonprotein sulfhydryl (NPSH) present in most mammalian cells. BSO exposures used in these experiments were not cytotoxic with the one exception that 2.0 mM BSO/24 hr reduced cell viability to approx.50%. However, alterations in either the cell doubling time(s) or the cell age density distribution(s) were not observed with the BSO exposures used to determine its radiosensitizing effect. BSO significantly radiosensitized hypoxic, but not aerobic, CHO cells when the GSH and NPSH concentrations were reduced to <10 and 20% of control, respectively, and maximum radiosensitivity was even achieved with μM concentrations of BSO. Furthermore, BSO exposure also enhanced the radiosensitizing effect of various concentrations of misonidazole on hypoxic CHO cells

  7. Condensation of interphase chromatin in nuclei of synchronized chinese hamster ovary (CHO-K1) cells.

    Science.gov (United States)

    Gacsi, Mariann; Nagy, Gabor; Pinter, Gabor; Basnakian, Alexei G; Banfalvi, Gaspar

    2005-01-01

    Reversibly permeabilized cells have been used to visualize interphase chromatin structures in the presence and absence of biotinylated nucleotides. By reversing permeabilization, it was possible to confirm the existence of a flexible chromatin folding pattern through a series of transient geometric forms such as supercoiled, circular forms, chromatin bodies, thin and thick fibers, and elongated chromosomes. Our results show that the incorporation of biotin-11-dUTP interferes with chromatin condensation, leading to the accumulation of decondensed chromatin structures. Chromatin condensation without nucleotide incorporation was also studied in cell populations synchronized by centrifugal elutriation. After reversal of permeabilization, nuclei were isolated and chromatin structures were visualized after DAPI staining by fluorescent microscopy. Decondensed veil-like structures were observed in the early S phase (at an average C-value of 2.21), supercoiled chromatin later in the early S (2, 55 C), fibrous structures in the early mid S phase (2, 76 C), ribboned structures in the mid-S phase (2, 98 C), continuous chromatin strings later in the mid-S phase (3,28), elongated prechromosomes in the late S-phase (3, 72 C), precondensed chromosomes at the end and after the S phase (3, 99 C). Fluorescent microscopy revealed that neither interphase nor metaphase chromosomes are separate entities but form a linear array arranged in a semicircle. Linear arrangement was confirmed by computer image analysis. PMID:15684719

  8. 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.

  9. 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

    glycans on EPO increased by 26%. The increase in sialic acid content was further verified by detailed profiling of the N-glycan structures using mass spectra (MS) analysis. In order to enhance antennarity/branching, UDP-N-acetylglucosamine: α-1,3-D-mannoside β1,4-N-acetylglucosaminyltransferase (Gn...

  10. Effects of hyperthermia on growth kinetics of Chinese hamster ovarian carcinoma cells

    International Nuclear Information System (INIS)

    The effects of hyperthermia on growth rate, cell volume, and density at plateau phase were studied in OvCa cells in monolayer culture in McCoy's 5a + 10% FCS. At 370C, T/sub G/=9.3 hr, cell density at plateau was 32 x 10/sup 4//cm/sup 2/, and mean cell volume decreased from 1200 μ/sup 3/ at the onset of exponential growth to 850 μ/sup 3/ in plateau phase. Cells were acutely heated for 60' at 430,30' at 440, or 15' at 450 (S.F.=20%) and incubated at 370; or were chronically heated for up to 80 hr at 39-420. Acute heating at 43-450 delayed cell division for appx 13 hr after which growth resumed with a T/sub G/=18 hr. Incubation at 39-400 had no effect on T/sub G/, but temperatures of 40.5-420 increased T/sub G/ at ΔH=176 kcal/mole. Increasing incubation temperature decreased cell density at plateau phase and altered cell volume kinetics. Cell density in plateau phase was 20 x 10/sup 4//cm/sup 2/ at 390, 13 x 10/sup 4//cm/sup 2/ at 400, 5x10/sup 4//cm/sup 2/ at 410. Growth was greatly reduced at 420 (T/sub G/=55 hr) and doubling did not occur before onset of cell lysis. The decrease in cell volume with growth of the culture was unaffected at 390. However, at temperatures ≥400 cell volume transiently increase, and the rate of decrease in volume that normally occurred with growth at 37-390 was less such that at 410 there was no decrease in volume at all before cells entered plateau phase. The authors' hypothesis is that the effects of heat on growth kinetics are related to alterations in rates of protein synthesis. This is currently being tested

  11. Hydroxyurea does not prevent synchronized G1 Chinese hamster cells from entering the DNA synthetic period

    International Nuclear Information System (INIS)

    Using very high concentrations of radioactively labeled thymidine, we show that synchronized G1 cells treated with hydroxyurea entered the DNA synthetic period at a time and rate indistinguishable from that of untreated cells, although the rate of DNA synthesis was greatly reduced in the drug-treated cultures. The DNA synthesized in the presence of hydroxyurea was less than or equal to 1 x 107 daltons, all of which could be chased into bulk DNA of approximately 3.5 x 108 daltons within 3 hr after removal of hydroxyurea. Hydroxyurea synchronized cells are apparently not blocked at the G1/S boundary but in the S phase itself

  12. Co-induction of glucose regulated proteins and adriamycin resistance in Chinese hamster cells

    International Nuclear Information System (INIS)

    Glucose deprivation, anoxia, calcium ionophore A23187 or 2-deoxyglucose all inducers of glucose regulated proteins (grps), also lead to a significant induction of resistance to the drug adriamycin. In the case of anoxia, A23187 and 2-deoxyglucose, the induction of resistance correlates with both the application of the inducing stress and the induction of grps. In the case of glucose deprivation, the onset of resistance correlates with the onset of glucose deprivation and precedes grp induction. Removal of each grp including condition results in the rapid disappearance of this resistance in a manner which correlates with the repression of the grps. This drug resistance can be induced in confluent cells or in actively proliferating cells, although the effect is greater in the more sensitive proliferating cells. Induction of heat shock proteins (hsps) does not appear to lead to any major change in adriamycin resistance. Grp induced cells retain less adriamycin than do controls with the greatest reduction occurring during anoxia, which is also the strongest inducer of grps and resistance. The authors propose that the application of a grp inducing stress leads to a concurrent induction in drug resistance, possibly via the translocation of grps in the cell. Finally, they also observed that adriamycin itself can induce both hsps and grps. It is possible that adriamycin exposure may correspondingly induce auto-resistance

  13. Radiosensitivity and thermosensitization of thermotolerant Chinese hamster cells and RIF-1 tumors

    International Nuclear Information System (INIS)

    CHO cells subline HA-1 were made thermotolerant by a priming heat treatment(430C, 30 min). Later, 4, 16, or 24 hr, they were either irradiated or heated (430C, 30 min) and irradiated. Thermotolerance had no effect on the radiation sensitivity of the cells as measured by the D0 value of the clonogenic survival curve. However the N value of the curve (width of shoulder) showed a significant increase at 24 hr, indicating an increased capacity to accumulate sublethal damage. The same priming treatment was given to RIF-1 tumors growing in C3H mice. Later, 24 hr, when the tumors were either irradiated or heated (430C, 30 min) and irradiated, it was found that thermotolerance had no effect on the radiosensitivity of the cells as measured by in vitro assay. However, thermal radiosensitization was not apparent 24 hr after the priming treatment

  14. Biosynthesis of fibronectin by human embryo fibroblasts

    International Nuclear Information System (INIS)

    The biosynthesis of fibronectin by human embryo fibroblasts, transformed by SV-40 virus, was investigated in intact cells and in a cell-free protein-synthesizing system on free and membrane-bound polyribosomes, isolated from the same cells. It was shown that fibronectin production in the culture medium by transformed fibroblasts is reduced by a factor of 4.5, while its percent content in the medium is decreased by a factor of 2. The content of fibronectin material precipitable by antibodies during the immunoprecipitation reaction proved to be somewhat greater in transformed cells than in normal cells, although the percentage was decreased by a factor of 1.5. However, the content of the fibronectin monomer with molecular weight 220 kilodaltons was 1.6 times as great in the cellular material of normal fibroblasts. In an investigation of fibronectin biosynthesis in a cell-free system it was established that in transformed cells 45% of the fibronectin is synthesized on free polyribosomes; in normal fibroblasts only 13% of the fibronectin is synthesized on free polyribosomes. It is suggested that one of the consequences of the transformation of human fibroblasts by SV-40 virus, leading to a decrease in fibronectin production, is the spatial uncoupling of the polyribosomes and membrane structures responsible for protein transport out of the cell, as a result of which a substantial portion of the fibronectin synthesized by transformed fibroblasts is subjected to intracellular degradation

  15. Fibroblasts in fibrosis: novel roles and mediators

    Directory of Open Access Journals (Sweden)

    Ryan Thomas Kendall

    2014-05-01

    Full Text Available Fibroblasts are the most common cell type of the connective tissues found throughout the body and the principal source of the extensive extracellular matrix (ECM characteristic of these tissues. They are also the central mediators of the pathological fibrotic accumulation of ECM and the cellular proliferation and differentiation that occurs in response to prolonged tissue injury and chronic inflammation. The transformation of the fibroblast cell lineage involves classical developmental signaling programs and includes a surprisingly diverse range of precursor cell types—most notably, myofibroblasts that are the apex of the fibrotic phenotype. Myofibroblasts display exaggerated ECM production; constitutively secrete and are hypersensitive to chemical signals such as cytokines, chemokines, and growth factors; and are endowed with a contractile apparatus allowing them to manipulate the ECM fibers physically to close open wounds. In addition to ECM production, fibroblasts have multiple concomitant biological roles, such as in wound healing, inflammation, and angiogenesis, which are each interwoven with the process of fibrosis. We now recognize many common fibroblast-related features across various physiological and pathological protracted processes. Indeed, a new appreciation has emerged for the role of noncancerous fibroblast interactions with tumors in cancer progression. Although the predominant current clinical treatments of fibrosis involve nonspecific immunosuppressive and anti-proliferative drugs, a variety of potential therapies under investigation specifically target fibroblast biology.

  16. Determination of elements in blood of golden hamster by NAA

    International Nuclear Information System (INIS)

    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)

  17. Rift Valley fever virus infection in golden Syrian hamsters.

    Directory of Open Access Journals (Sweden)

    Dionna Scharton

    Full Text Available Rift Valley fever virus (RVFV is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.

  18. 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. PMID:19799607

  19. Nontoxigenic Clostridium difficile Protects Hamsters against Challenge with Historic and Epidemic Strains of Toxigenic BI/NAP1/027 C. difficile

    OpenAIRE

    Nagaro, Kristin J.; Phillips, S. Tyler; Cheknis, Adam K.; Sambol, Susan P.; Zukowski, Walter E.; Johnson, Stuart; Gerding, Dale N.

    2013-01-01

    Nontoxigenic Clostridium difficile (NTCD) has been shown to prevent fatal C. difficile infection in the hamster model when hamsters are challenged with standard toxigenic C. difficile strains. The purpose of this study was to determine if NTCD can prevent C. difficile infection in the hamster model when hamsters are challenged with restriction endonuclease analysis group BI C. difficile strains. Groups of 10 hamsters were given oral clindamycin, followed on day 2 by 106 CFU of spores of NTCD ...

  20. 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)

  1. Lifelong persistent infection of hamster brain by human adenovirus type 6.

    Directory of Open Access Journals (Sweden)

    Yabe,Yoshiro

    1988-02-01

    Full Text Available To establish an experimental persistent infection of the brain with human adenoviruses, adenovirus type 6 (ad 6 was inoculated intracerebrally into young adult hamsters. Hamsters appeared languid for a few days after inoculation, but recovered rapidly. By cocultivation of tissue fragments with HeLa cells, ad 6 was always recovered from the brains of hamsters throughout their lives, as long as 29 months, indicating the establishment of a lifelong persistent infection. Except for the first few days after inoculation, however, attempts to recover virus by inoculation of tissue extracts onto HeLa cells or by cultivation of tissue fragments alone were unsuccessful.

  2. A comparative study of the pulmonary effects of NO2 in the rat and hamster.

    OpenAIRE

    Foster, J R; Cottrell, R C; Herod, I. A.; Atkinson, H. A.; Miller, K

    1985-01-01

    A study of the response of rat and hamster to nitrogen dioxide (NO2) under identical conditions has been undertaken. Exposure to 20 parts/IO6 NO2 for 24 h produced a mild cytotoxic effect on the terminal bronchiole and proximal alveoli in the rat, whereas the hamster developed a moderate to severe bronchiolitis and alveolitis. Electron microscopic examination of tissue sections showed accumulation of surfactant in lamellar bodies of the alveolar type II cell in the rat but not in the hamster,...

  3. N-cadherin is overexpressed in Crohn's stricture fibroblasts and promotes intestinal fibroblast migration.

    LENUS (Irish Health Repository)

    Burke, John P

    2012-02-01

    BACKGROUND: Intestinal fibroblasts mediate stricture formation in Crohn\\'s disease (CD). Transforming growth factor-beta (TGF-beta) is important in fibroblast activation, while cell attachment and migration is regulated by the adhesion molecule N-cadherin. The aim of this study was to investigate the expression and function of N-cadherin in intestinal fibroblasts in patients with fibrostenosing CD. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies from patients undergoing resection for terminal ileal fibrostenosing CD (n = 14) or controls patients (n = 8). N-cadherin expression was assessed using Western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Fibroblasts were stimulated with TGF-beta and selective pathway inhibitors Y27632, PD98050, and LY294002 were used to examine the Rho\\/ROCK, ERK-1\\/2, and Akt signaling pathways, respectively. Cell migration was assessed using a scratch wound assay. N-cadherin was selectively overexpressed using a plasmid. RESULTS: Fibroblasts from fibrostenosing CD express increased constitutive N-cadherin mRNA and protein and exhibit enhanced basal cell migration relative to those from directly adjacent normal bowel. Control fibroblasts treated with TGF-beta induced N-cadherin in a dose-dependent manner which was inhibited by Rho\\/ROCK and Akt pathway modulation. Control fibroblasts exhibited enhanced cell migration in response to treatment with TGF-beta or transfection with an N-cadherin plasmid. CONCLUSIONS: Fibroblasts from strictures in CD express increased constitutive N-cadherin and exhibit enhanced basal cell migration. TGF-beta is a potent inducer of N-cadherin in intestinal fibroblasts resulting in enhanced cell migration. The TGF-beta-mediated induction of N-cadherin may potentiate Crohn\\'s stricture formation.

  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. CHINESE JOURNAL OF CHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  6. Chinese Culture and Leadership.

    Science.gov (United States)

    Wong, Kam-Cheung

    2001-01-01

    Describes essential characteristics of Chinese philosophical tradition; Discusses Western perspectives on value leadership in education, particularly moral leadership. Discuses moral leadership from a Chinese philosophical perspective, especially Confucianism. Draws implications for using Chinese cultural and philosophical traditions to develop…

  7. The Chinese Banking System

    OpenAIRE

    Grant Turner; Nicholas Tan; Dena Sadeghian

    2012-01-01

    The Chinese banking system is critical to the functioning of the Chinese economy, being the main conduit through which savings are allocated to investment opportunities. Banking activity in China has grown rapidly over the past decade in association with the expansion of the Chinese economy, and the Chinese banking system now includes some of the world’s largest banks. Chinese banks have become more commercially orientated over this period, although the Chinese Government retains considerable...

  8. Kisspeptin and the seasonal control of reproduction in hamsters

    DEFF Research Database (Denmark)

    Simonneaux, Valérie; Ansel, Laura; Revel, Florent G;

    2008-01-01

    Reproduction is a complex and energy demanding function. When internal and external conditions might impair reproductive success (negative energy balance, stress, harsh season) reproductive activity has to be repressed. Recent evidence suggests that these inhibitory mechanisms operate on Kiss1......-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...... hormone whose secretion is adjusted to night length. The photoperiodic variation in circulating melatonin has been shown to synchronize reproductive activity with seasons, but the mechanisms involved in this effect of melatonin were so far unknown. Recently we have observed that Kiss1 mRNA level in the...

  9. 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.

  10. Vaccination against hepatitis B: the Chinese experience

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yi-hua; WU Chao; ZHUANG Hui

    2009-01-01

    Objective To review the implementation of mass vaccination of hepatitis B vaccine and its critical role in prevention of hepatitis B virus infection in China. Data sources The data were mainly from PubMed, China Hospital Knowledge Database, and other popular Chinese journals published from 1980 to 2008. The search term was "hepatitis B vaccine". Study selection Original studies conducted in China and critical reviews authored by principal investigators in the field of hepatology in China were selected. Results Chinese investigators started to develop hepatitis B vaccine in late 1970s. The first home-made plasma-derived vaccine became available in 1986, which has been completely replaced by the domestically produced recombinant (yeast or Chinese hamster ovary cell) vaccine since 2001. China health authority recommended vaccinating all infants in 1992. From then on, China has put tremendous efforts in implementation of mass vaccination. The overall coverage of hepatitis B vaccine in infants has increased steadily and reached more than 95.0% in urban and 83.0%--97.0% in rural areas. The chronic HBV carrier rate in children <10 years of age decreased from 10.0% before the mass vaccination to 1.0%-2.0% in 2006, and that in general population decreased from 10.0% to 7.2%; overall, the nationwide mass hepatitis B vaccination has reduced more than 30 million of chronic HBV infections and HBV related severe sequlae. Conclusion The Chinese successful experience in control of hepatitis B by mass vaccination offers an example for any unindustrialized country whoever is committed to control this disease.

  11. Fluoxetine disrupts motivation and GABAergic signaling in adolescent female hamsters.

    Science.gov (United States)

    Shannonhouse, John L; DuBois, Dustin W; Fincher, Annette S; Vela, Alejandra M; Henry, Morgan M; Wellman, Paul J; Frye, Gerald D; Morgan, Caurnel

    2016-08-01

    Initial antidepressant treatment can paradoxically worsen symptoms in depressed adolescents by undetermined mechanisms. Interestingly, antidepressants modulate GABAA receptors, which mediate paradoxical effects of other therapeutic drugs, particularly in females. Although the neuroanatomic site of action for this paradox is unknown, elevated GABAA receptor signaling in the nucleus accumbens can disrupt motivation. We assessed fluoxetine's effects on motivated behaviors in pubescent female hamsters - anhedonia in the reward investigational preference (RIP) test as well as anxiety in the anxiety-related feeding/exploration conflict (AFEC) test. We also assessed accumbal signaling by RT-PCR and electrophysiology. Fluoxetine initially worsened motivated behaviors at puberty, relative to adulthood. It also failed to improve these behaviors as pubescent hamsters transitioned into adulthood. Low accumbal mRNA levels of multiple GABAA receptor subunits and GABA-synthesizing enzyme, GAD67, assessed by RT-PCR, suggested low GABAergic tone at puberty. Nonetheless, rapid fluoxetine-induced reductions of α5GABAA receptor and BDNF mRNA levels at puberty were consistent with age-related differences in GABAergic responses to fluoxetine and disruption of the motivational state. Whole-cell patch clamping of accumbal slices also suggested low GABAergic tone by the low amplitude of miniature inhibitory postsynaptic currents (mIPSCs) at puberty. It also confirmed age-related differences in GABAergic responses to fluoxetine. Specifically, fluoxetine potentiated mIPSC amplitude and frequency at puberty, but attenuated the amplitude during adulthood. These results implicate GABAergic tone and GABAA receptor plasticity in adverse motivational responses and resistance to fluoxetine during adolescence. PMID:27068049

  12. Retention of inhaled particles in hamsters with pulmonary fibrosis

    International Nuclear Information System (INIS)

    Aerosol retention was studied in hamsters 30, 60, and 90 days after the initiation of interstitial pulmonary fibrosis by a combination of bleomycin (bleo), 0.16 U/100 g body weight given intratracheally, and O2, for 72 h. Groups of bleo-O2-treated and control animals were exposed (awake) for 25 min to a 99mTc-labeled insoluble aerosol (activity median aerodynamic diameter, 0.45 micron; geometric standard deviation, 1.3). Within 5 min after exposure, the hamsters were killed and their lungs were excised and dried at total lung capacity, and sliced into 1-mm sections. Slices were dissected into pieces, and an evenness index (EI) was calculated for each piece (formula: see text). With uniformity of retention, all Els would be 1. The distribution of Els in control animals had a mean of 1.0 and a SD of 0.27; 0% of the Els were less than or equal to 0.20. Total retention diminished and was less uniform in bleo-O2-treated animals. At 30 days, the SD increased to 0.62, and 6% of the Els were less than or equal to 0.20. At 60 and 90 days, nonuniformity decreased but was still greater than that in the control animals (SD60 . 0.42, SD90 . 0.36). When examined histologically, individual pieces with low Els had more disease than those with high Els. Local decreases in compliance caused by fibrosis may have altered regional ventilation and retention. Our data also correlate with the progression of fibrosis from a focal lesion at 30 days to a more diffuse lesion at 90 days

  13. 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.

  14. Study of radiation effects on DMBA induced hamster lingual carcinoma

    International Nuclear Information System (INIS)

    A morphological and histo-pathological study of DMBA-induced carcinoma of the tongue in hamsters was carried out. The tongues of eighty golden hamsters were coated with a 1% DMBA acetone solution three times a week to induce carcinoma. The ulceration rate was about 100% in three to five months, and the ulceration process was followed by microangiography using Hayashi's drawing ink. Papillomatous or carcinomatous tongues were irradiated once with 60Co-γ rays. The total absorption dosage was 2000 rad. Then 67Ga-citrate and 57Co-bleomycin (57Co-BLM), were injected into the abdominal cavity. The amount of uptake of the reagents by the tumor was clearly low on three days after irradiation and increased on ten days after irradiation. This variation was more remarkable in the case of carcinoma than in the case of papilloma. 67Ga-citrate concentration ratio of carcinoma-to-organ and of papilloma-to-organ was the same as 57Co-BLM concentration ratio of carcinoma-to-organ and of papilloma-to-organ. Vascular changes was observed by means of microangiography, and the ratio of vascular area was measured by an image analyzer. The ratio increased rapidly with expansion of the tumor vessel and the exuding of contrast media one day after irradiation, decreased with damage of the vessel neighboring the tumor two days after irradiation, slightly increased with the development of a minimal vessel in the neighborhood of tumor three days after irradiation, and slightly decreased with the death at the center of tumor on ten days. These morphological variations of the tumor vessel were closely related to those of labeled tumor seekers. (Nakanishi, T.)

  15. 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

  16. INVESTIGATION OF POSSIBLE AGE EFFECTS ON MEIOTIC CHROMOSOMAL RECOMBINATION AND SEGREGATION IN ARMENIAN HAMSTER SPERMATOCYTES

    Science.gov (United States)

    Male Armenian hamsters (Cricetulus migratorius; 2N:22) were evaluated for age effects upon meiotic recombination and aneuploidy incidence. Primary spermatocytes from young and old animals revealed similar chiasma frequencies. The incidence of terminal-type chiasmata in sex bivale...

  17. Effects of propionyl-L-carnitine on ischemia-reperfusion injury in hamster cheek pouch microcirculation.

    OpenAIRE

    DomingaLapi; LinaSabatino; GiovannaAltobelli

    2010-01-01

    Background and Purpose Propionyl-L-carnitine (pLc) exerts protective effects in different experimental models of ischemia-reperfusion (I/R). The aim of the present study was to assess the effects of intravenously and topically applied pLc on microvascular permeability increase induced by I/R in the hamster check pouch preparation. Methods The hamster check pouch microcirculation was visualized by fluorescence microscopy. Microvascular permeability, leukocyte adhesion to venular walls, perfus...

  18. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus)

    OpenAIRE

    Butler, Matthew P.; Zucker, Irving

    2009-01-01

    The extent to which changing day lengths synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the se...

  19. Chronic Ethanol Intake Modulates Photic and Non-Photic Circadian Phase Responses in the Syrian Hamster

    OpenAIRE

    Seggio, Joseph A.; Logan, Ryan W.; Rosenwasser, Alan M.

    2007-01-01

    Chronic alcohol intake disrupts sleep and other circadian biological rhythms in both human alcoholics and in experimental animals. Recent studies from our laboratory indicate that these effects may be due, in part, to ethanol-induced alterations in fundamental properties of the circadian pacemaker. The present study explored the effects of chronic voluntary ethanol intake (25% v/v) on circadian phase responses to both photic and non-photic stimuli in Syrian hamsters. Hamsters were used in the...

  20. Gonadal Hormones Modulate the Display of Conditioned Defeat in Male Syrian Hamsters

    OpenAIRE

    Solomon, Matia B.; Karom, Mary C.; Norvelle, Alisa; Markham, Chris A; Erwin, W. Daniel; Huhman, Kim L.

    2009-01-01

    It has been widely reported that gonadal hormones influence the display of aggression in Syrian hamsters; conversely, much less is known about whether gonadal hormones modulate submissive/defensive behaviors in these animals. Following social defeat, male hamsters no longer display normal territorial aggression but instead display submissive/defensive behavior in the presence of a smaller opponent, a phenomenon we have termed conditioned defeat (CD). The purpose of the present study was to ex...

  1. 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.

  2. Use of hamster as a model to study diet-induced atherosclerosis

    Directory of Open Access Journals (Sweden)

    Lichtenstein Alice H

    2010-12-01

    Full Text Available Abstract Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apoB-100 and intestinal apoB-48 secretion, and uptake of the majority of LDL cholesterol via the LDL receptor pathway. Early work suggested hamsters fed high cholesterol and saturated fat diets responded similarly to humans in terms of lipoprotein metabolism and aortic lesion morphology. Recent work has not consistently replicated these findings. Reviewed was the literature related to controlled hamster feeding studies that assessed the effect of strain, background diet (non-purified, semi-purified and dietary perturbation (cholesterol and/or fat on plasma lipoprotein profiles and atherosclerotic lesion formation. F1B hamsters fed a non-purified cholesterol/fat-supplemented diet had more atherogenic lipoprotein profiles (nHDL-C > HDL-C than other hamster strains or hamsters fed cholesterol/fat-supplemented semi-purified diets. However, fat type; saturated (SFA, monounsaturated or n-6 polyunsaturated (PUFA had less of an effect on plasma lipoprotein concentrations. Cholesterol- and fish oil-supplemented semi-purified diets yielded highly variable results when compared to SFA or n-6 PUFA, which were antithetical to responses observed in humans. Dietary cholesterol and fat resulted in inconsistent effects on aortic lipid accumulation. No hamster strain was reported to consistently develop lesions regardless of background diet, dietary cholesterol or dietary fat type amount. In conclusion, at this time the Golden-Syrian hamster does not appear to be a useful model to determine the mechanism(s of diet-induced development of atherosclerotic lesions.

  3. Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure

    OpenAIRE

    ThomasGerardHampton; AjitKale; HemmiBhagavan

    2012-01-01

    Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The delta-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness a...

  4. Dissociation of Ultradian and Circadian Phenotypes in Female and Male Siberian Hamsters

    OpenAIRE

    Prendergast, Brian J.; Cisse, Yasmine M.; Cable, Erin J.; Zucker, Irving

    2012-01-01

    Three experiments addressed whether pronounced alterations in the circadian system yielded concomitant changes in ultradian timing. Female Siberian hamsters were housed in a 16L:8D photoperiod after being subjected to a disruptive phase-shifting protocol that produced 3 distinct permanent circadian phenotypes: some hamsters entrained their circadian rhythms (CRs) with predominantly nocturnal locomotor activity (ENTR), others displayed free-running CRs (FR), and a third cohort was circadian ar...

  5. Male Syrian Hamsters Demonstrate a Conditioned Place Preference for Sexual Behavior and Female Chemosensory Stimuli

    OpenAIRE

    Bell, Margaret R.; Meerts, Sarah H.; Sisk, Cheryl L.

    2010-01-01

    Sexual behavior is a natural reward for many rodent species, and it often includes chemosensory-directed components. Chemosensory stimuli themselves may also be rewarding. Conditioned place preference (CPP) is one paradigm frequently used to test the rewarding properties of a range of stimuli. Males and females of several rodent species show a CPP for sexual behavior, however, it is currently unknown whether sexual behavior can induce a CPP in male Syrian hamsters. As male Syrian hamsters are...

  6. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters

    OpenAIRE

    Bradley, Sean P.; Prendergast, Brian J.

    2014-01-01

    Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9 h light/day) photoperiods w...

  7. Effects of Porcine Pancreatic Enzymes on the Pancreas of Hamsters. Part 2: Carcinogenesis Studies

    OpenAIRE

    Fumiaki Nozawa; Mehmet Yalniz; Murat Saruc; Jens Standop; Hiroshi Egami; Pour, Parviz M.

    2012-01-01

    Context Our previous study suggested that porcine pancreatic extract in hamsters with peripheral insulin resistance, normalizes insulin output, islet size and pancreatic DNA synthetic rate. It also inhibited the growth of human pancreatic cancer cells in nude mice. Objective To examine the potential value of the porcine pancreatic extract in controlling pancreatic carcinogenesis in this model, the present experiment was performed. Design Hamsters were fed a high fat diet and four wee...

  8. Autoradiographic localization of tritiated dihydrotestosterone in the flank organ of the albino hamster

    International Nuclear Information System (INIS)

    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 ( [3H]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. [3H]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 [3H]DHT in animals pretreated with excessive quantities of unlabeled DHT. Steroid metabolites of [3H] 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

  9. Beneficial effects of noni (Morinda citrifolia L.) juice on livers of high-fat dietary hamsters.

    Science.gov (United States)

    Lin, Yi-Ling; Chang, Yuan-Yen; Yang, Deng-Jye; Tzang, Bor-Show; Chen, Yi-Chen

    2013-09-01

    Polyphenols in noni juice (NJ) are mainly composed of phenolic acids, mainly gentisic, p-hydroxybenoic, and chlorogenic acids. To investigate the beneficial effects of NJ on the liver, hamsters were fed with two diets, normal-fat and high-fat diets. Furthermore, high-fat dietary hamsters were received distilled water, and 3, 6, and 9 mL NJ/kg BW, respectively. After a 6-week feeding period, the increased (p<0.05) sizes of liver and visceral fat in high-fat dietary hamsters compared to the control hamsters were ameliorated (p<0.05) by NJ supplementation. NJ also decreased (p<0.05) serum/liver lipids but enhanced (p<0.05) daily faecal lipid/bile acid outputs in the high-fat dietary hamsters. High-fat dietary hamsters supplemented with NJ had higher (p<0.05) liver antioxidant capacities but lowered (p<0.05) liver iNOS, COX-2, TNF-α, and IL-1β expressions, gelatinolytic levels of MMP9, and serum ALT values compared to those without NJ. Hence, NJ protects liver against a high-fat dietary habit via regulations of antioxidative and anti-inflammatory responses. PMID:23578611

  10. Electroencephalography in the diagnosis of hydrocephalus in golden hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Bali, M S; Gebhardt-Henrich, S; Keller, P; Steiger, A; Gattermann, R; Bergamasco, L; Kronen, P; Doherr, M G; Botteron, C; Tomek, A; Jaggy, A

    2008-04-01

    The golden hamster (Mesocricetus auratus) is a popular laboratory animal and is used in a multitude of behavioural studies. However, it has been shown that it suffers from different forms of hereditary hydrocephalus, which may result in behavioural changes. This prospective study was designed to look into the usefulness of electroencephalography (EEG) measurements in the diagnosis of hydrocephalus in hamsters. The EEGs of the hydrocephalic hamsters were evaluated double-blind and showed a high-voltage slow wave activity, with a fast activity superimposed onto it. This pattern has already been well described in other hydrocephalic species and differed significantly from the EEGs that were obtained from the normal hamsters. It was concluded from our study that a background activity with an amplitude over 50 muV in combination with a frequency of < or =5 Hz was highly indicative of hydrocephalus in young hamsters. We believe that the EEG could be a very useful diagnostic tool in the screening for hydrocephalus in hamsters. PMID:18435879

  11. Chinese Calendar and Chinese Telegraphic Code.

    Science.gov (United States)

    Defense Language Inst., Monterey, CA.

    This manual contains: (1) Chinese calendars for the hundred years from 1881 to 1980; and (2) the Chinese telegraphic code. Each page in Part One presents the calendar for each year in both Chinese and English. There are 97 charts in Part Two representing the telegraphic code. (AMH)

  12. Cryopreservation of canine ovarian and testicular fibroblasts.

    Science.gov (United States)

    Yu, Il-Jeoung; Leibo, S P; Songsasen, Nucharin; Dresser, Betsy L; Kim, In-Shik

    2009-01-01

    To derive a practical procedure to store canine somatic cells, fibroblasts isolated from testicular or ovarian tissues were cryopreserved in 1.2 M ethylene glycol or in 1.2 M dimethylsulfoxide prepared in Dulbecco's Modified Eagle Medium as cryoprotectants, and were frozen either in plastic straws or vials. Thawed cells were cultured for 24 hr at 38.5 degree C in a humidified atmosphere of 5 percent CO2 95 percent air, and then their membrane integrity was assayed with a double fluorescent stain, Fertilight. In addition, frozen-thawed fibroblasts were cultured for 4 days, and then their functional survival was measured after staining small colonies with trypan blue. After freezing and thawing, membrane integrity of testicular fibroblasts was 55-70 percent and functional survival ranged from 20-40 percent. With frozen-thawed ovarian cells, the average membrane integrity was 55-75 percent and the average functional survival was 35-40 percent. When frozen in ethylene glycol, functional survival of ovarian fibroblasts was significantly higher than that of testicular cells (P less than 0.05). These methods should prove useful to preserve cells collected from canids in the wild. PMID:19750243

  13. Fibroblast growth factor 23--et fosfatregulerende hormon

    DEFF Research Database (Denmark)

    Beck-Nielsen, Signe Sparre; Pedersen, Susanne Møller; Kassem, Moustapha;

    2010-01-01

    Fibroblast growth factor 23 (FGF23) is a recently identified phosphatonin. Its main physiological functions are to maintain serum phosphate within its reference range and to counter regulate the effects of vitamin D. Diseases correlated to high serum values of FGF23 are hypophosphatemic rickets, ...

  14. Fibroblast growth factors in neurodevelopment and psychopathology

    NARCIS (Netherlands)

    Terwisscha van Scheltinga, Afke F; Bakker, Steven C; Kahn, René S; Kas, Martien J H

    2013-01-01

    In psychiatric disorders, the effect of genetic and environmental factors may converge on molecular pathways and brain circuits related to growth factor functioning. In this review, we describe how disturbances in fibroblast growth factors (FGFs) and their receptors influence behavior by affecting b

  15. Hamster-Adapted Sin Nombre Virus Causes Disseminated Infection and Efficiently Replicates in Pulmonary Endothelial Cells without Signs of Disease

    OpenAIRE

    Safronetz, David; Prescott, Joseph; Haddock, Elaine; Scott, Dana P.; Feldmann, Heinz; Ebihara, Hideki

    2013-01-01

    To date, a laboratory animal model for the study of Sin Nombre virus (SNV) infection or associated disease has not been described. Unlike infection with Andes virus, which causes lethal hantavirus pulmonary syndrome (HPS)-like disease in hamsters, SNV infection is short-lived, with no viremia and little dissemination. Here we investigated the effect of passaging SNV in hamsters. We found that a host-adapted SNV achieves prolonged and disseminated infection in hamsters, including efficient rep...

  16. Isolation and characterization of the hamster gadd153 gene. Activation of promoter activity by agents that damage DNA

    Energy Technology Data Exchange (ETDEWEB)

    Luethy, J.D.; Fargnoli, J.; Park, J.S.; Fornace, A.J. Jr.; Holbrook, N.J. (National Institute on Aging, Baltimore, MD (USA))

    1990-09-25

    A group of five cDNA clones, representing the gadd genes, were recently isolated from Chinese hamster ovary (CHO) cells as genes induced upon growth arrest and after DNA damage. We have isolated and characterized one of these genes, gadd153. The gene spans five kilobases and contains four exons. The 5'-flanking region of the gene, within 420 base pairs of the transcription initiation site, contains a number of cis elements associated with transcriptional regulation in other genes. These include a Hogness box, ATAAAA, an inverted GCCAAT box; seven SP1 transcription factor binding sites, and an AP-1 site. This region is rich in G + C content (greater than 70%) and contains an unusually long stretch of alternating CpG residues. The 800-base pair region immediately upstream of the transcription start site can drive expression of the bacterial chloramphenicol acetyltransferase (CAT) gene, but only in its endogenous orientation, in three different cell lines: HeLa, CHO, and Jurkat. The gadd153 promoter is strongly activated by methyl methanesulfonate, hydrogen peroxide, and UV irradiation, but not by growth arrest signals. This suggests that separate and very different regulatory pathways are involved in the induction of the gadd153 gene by growth cessation and DNA damage.

  17. Management of Chinese restaurant

    OpenAIRE

    Cui , Longbo

    2009-01-01

    With Chinese economy developing rapidly, the Chinese restaurant is under the spotlight, but the management of Chinese restaurant is weak at the moment, especially on the service management, which is an important part of service management in the Chinese restaurant. On the other hand, the managers of Chinese restaurant should pay more attention on the service management for instance brand, service innovation. Service management is core and essential concept for every service company recently, ...

  18. Mouse embryonic fibroblasts exhibit extensive developmental and phenotypic diversity

    Science.gov (United States)

    Singhal, Prabhat K.; Sassi, Slim; Lan, Lan; Au, Patrick; Halvorsen, Stefan C.; Fukumura, Dai; Jain, Rakesh K.; Seed, Brian

    2016-01-01

    Analysis of embryonic fibroblasts from GFP reporter mice indicates that the fibroblast cell type harbors a large collection of developmentally and phenotypically heterogeneous subtypes. Some of these cells exhibit multipotency, whereas others do not. Multiparameter flow cytometry analysis shows that a large number of distinct populations of fibroblast-like cells can be found in cultures initiated from different embryonic organs, and cells sorted according to their surface phenotype typically retain their characteristics on continued propagation in culture. Similarly, surface phenotypes of individual cloned fibroblast-like cells exhibit significant variation. The fibroblast cell class appears to contain a very large number of denumerable subtypes. PMID:26699463

  19. DEVELOPMENT OF MICE AND HAMSTER EMBRYOS IN KSOMAA AND HECM-6 MEDIUM

    Directory of Open Access Journals (Sweden)

    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.

  20. LipL21 mRNA expression in lungs of hamsters infected with pathogenic Leptospira

    Institute of Scientific and Technical Information of China (English)

    Chintana Chirathaworn; Namo Suksomyos; Somchai Utivamek; Somboon Keelawat; Duangjai Suwancharoen; Duangporn Phulsuksombati; Yong Poovorawan

    2009-01-01

    Objective:Pulmonary haemorrhage is an increasing cause of death in leptospirosis patients.However,molecu-lar mechanism underlying pathologies in this organ is not clearly understood.It has been shown that sodium transport was disturbed following Leptospira infection.LipL21 is the second abundant outer membrane protein found only in pathogenic Leptospira.Its expression in vivo has been shown which suggests that this protein may be involved in survival in hosts or pathogenesis.However,the expression of this protein in host organs and its role in lung pathology has not been demonstrated.In this study we demonstrated the expression of LipL21 in lungs of hamsters infected with pathogenic Leptospira.Methods:Lung tissues were collected from Golden Syri-an hamsters injected with Leptospira interrogans serovar Pyrogenes at days 3,5 and 7 post-infection.Four ham-sters were used for each time point.Lungs from non-infected hamsters were collected as a control group.Li-pL21 mRNA expression in lung tissues was investigated by reverse transcription and nested PCR.Results:Li-pL21 mRNA expression was detected in all lung tissues from hamsters infected with pathogenic Leptospira.No PCR product was detected when tissues from non-infected hamsters were investigated.Conclusion:Our data demonstrated that LipL21 is expressed in lungs of hamsters infected with pathogenic Leptospira.Additional ex-periments such as quantitation and localization of LipL21 expression in lungs will provide further information whether this protein is involved in pathogenesis.

  1. Vomeronasal organ lesion disrupts social odor recognition, behaviors and fitness in golden hamsters.

    Science.gov (United States)

    Liu, Yingjuan; Zhang, Jinhua; Liu, Dingzhen; Zhang, Jianxu

    2014-06-01

    Most studies support the viewpoint that the vomeronasal organ has a profound effect on conspecific odor recognition, scent marking and mating behavior in the golden hamster (Mesocricetus auratus). However, the role of the vomeronasal organ in social odor recognition, social interaction and fitness is not well understood. Therefore, we conducted a series of behavioral and physiological tests to examine the referred points in golden hamster. We found that male hamsters with vomeronasal organ lesion showed no preference between a predator odor (the anal gland secretion of the Siberian weasels (Mustela sibirica) and putative female pheromone components (myristic acid and palmitic acid), but were still able to discriminate between these 2 kinds of odors. In behavioral tests of anxiety, we found that vomeronasal organ removal causes female hamsters to spend much less time in center grids and to cross fewer center grids and males to make fewer crossings between light and dark boxes than sham-operated controls. This indicates that a chronic vomeronasal organ lesion induced anxious responses in females. In aggressive behavioral tests, we found that a chronic vomeronasal organ lesion decreased agonistic behavior in female hamsters but not in males. The pup growth and litter size show no differences between the 2 groups. All together, our data suggested that vomeronasal organ ablation disrupted the olfactory recognition of social chemosignals in males, and induced anxiety-like and aggressive behavior changes in females. However, a vomeronasal organ lesion did not affect the reproductive capacity and fitness of hamsters. Our studies may have important implications concerning the role of the vomeronasal organ in golden hamsters and also in rodents. PMID:24952966

  2. The dystrophic hamster: an animal model of alveolar hypoventilation.

    Science.gov (United States)

    Schlenker, E H; Burbach, J A

    1991-11-01

    The BIO 14.6 dystrophic hamster (DH) is a genetically determined animal model of alveolar hypoventilation (AH) that exhibits a ventilatory control pattern of compensation and then decompensation similar to that in progressive forms of muscular dystrophy and nonprogressive congenital myopathies in humans. Possible causes of AH in the DH include respiratory muscle weakness, ventilation-to-perfusion inequalities, and an inadequate drive to breathe. Histochemical and contractile abnormalities of the diaphragm, reduced lung surface area available for gas exchange, abnormal pulmonary microvascular reactivity to hypoxia, altered levels of neurochemicals, and abnormal cellular regulation of calcium are among the specific factors that may contribute to the development of AH. The potential role of hypothyroidism in the development of AH is reviewed because many hypothyroid patients exhibit AH and other ventilatory dysfunctions, hypothyroidism is present in human patients and animals with muscular dystrophy, and thyroid status is known to influence lung architecture, myocyte function, and neural activity. Additional studies linking neurohormonal signals, transcellular signal processing, and control of ventilation in the DH may help us understand the etiology of AH in human disease. PMID:1684789

  3. Red Yeast Rice Increases Excretion of Bile Acids in Hamsters

    Institute of Scientific and Technical Information of China (English)

    KA-YING MA; ZE-SHENG ZHANG; SHU-XIN ZHAO; QI CHANG; YIN-MEI WONG; SAI YING VENUS YEUNG; YU HUANG; ZHEN-YU CHEN

    2009-01-01

    Objectives To investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism. Methods Three groups of hamsters were fed either the control diet or one of the two experimental diets containing by weight 0.1% RYR (0.1RYR) or 0.3% RYR (0.3RYR). Blood (0.5 mL) was collected from the retro-orbital sinus into a heparinized capillary tube at the end of week 0,3, and 6.Plasma lipoproteins were measured using enzymatic kits, while fecal neutral and acidic sterols were quantified using a gas-liquid chromatography. Results Plasma total cholesterol was reduced by 12% in 0.1RYR group and by 18% in 0.3RYR group compared with the control value. Similarly, plasma triacylglycerol was decreased by ll% in 0.1RYR group and by 24% in 0.3RYR group. Western blotting analysis demonstrated that RYR had no effect on sterol regulatory element binding protein 2, liver X receptor, 3-hydroxy-3-methylglutary-CoA reductase, LDL receptor, and cholesterol-7α-hydroxylase. HPLC analysis confirmed that RYR contained 0.88% monacolin K.It was recently found that RYR supplementation increased excretion of fecal acidic sterols by 3-4 folds compared with the control value. Conclusion Hypocholesterolemic activity of RYR is mediated at least partially by enhancement of acidic sterol excretion.

  4. Chlorpromazine distribution in hamsters and mice bearing transplantable melanoma

    International Nuclear Information System (INIS)

    Chlorpromazine (CPZ) distribution was measured in tissues of Syrian golden hamsters bearing Greene melanoma and in BALB/c mice bearing Harding-Passey melanoma. Distribution was evaluated as a function of time (0.5 to 14 days) and as a function of single and multiple doses (up to five) of from 5 to 50 mg CPZ per kg body weight. Routes of administration (i.p., i.v., p.o.) were compared. The physiological behavior of CPZ is of interest as it is used extensively as a tranquilizing drug (Thorazine). Further, since CPZ binds to the pigment melanin, the possibility exists of using CPZ to transport diagnostic or therapeutic agents to melanoma. It was found that, at 2 days postinjection, tumor/tissue concentration ratios exceeded 10 for metabolizing organs, such as liver, and 100 for background tissues, such as blood and muscle. Absolute concentrations of CPZ in tumor exceeding 100 μg CPZ per g tumor were obtained with both single and multiple doses. This selective high concentration in tumor would make CPZ an ideal vehicle for the transport of boron to tumor for use in neutron capture therapy via the 10B(n,α)7Li reaction

  5. HAMSTER: visualizing microarray experiments as a set of minimum spanning trees

    Directory of Open Access Journals (Sweden)

    Harada Hajime

    2009-11-01

    Full Text Available Abstract Background Visualization tools allow researchers to obtain a global view of the interrelationships between the probes or experiments of a gene expression (e.g. microarray data set. Some existing methods include hierarchical clustering and k-means. In recent years, others have proposed applying minimum spanning trees (MST for microarray clustering. Although MST-based clustering is formally equivalent to the dendrograms produced by hierarchical clustering under certain conditions; visually they can be quite different. Methods HAMSTER (Helpful Abstraction using Minimum Spanning Trees for Expression Relations is an open source system for generating a set of MSTs from the experiments of a microarray data set. While previous works have generated a single MST from a data set for data clustering, we recursively merge experiments and repeat this process to obtain a set of MSTs for data visualization. Depending on the parameters chosen, each tree is analogous to a snapshot of one step of the hierarchical clustering process. We scored and ranked these trees using one of three proposed schemes. HAMSTER is implemented in C++ and makes use of Graphviz for laying out each MST. Results We report on the running time of HAMSTER and demonstrate using data sets from the NCBI Gene Expression Omnibus (GEO that the images created by HAMSTER offer insights that differ from the dendrograms of hierarchical clustering. In addition to the C++ program which is available as open source, we also provided a web-based version (HAMSTER+ which allows users to apply our system through a web browser without any computer programming knowledge. Conclusion Researchers may find it helpful to include HAMSTER in their microarray analysis workflow as it can offer insights that differ from hierarchical clustering. We believe that HAMSTER would be useful for certain types of gradient data sets (e.g time-series data and data that indicate relationships between cells/tissues. Both

  6. The effect of dietary vitamin A on NO2 exposure on the hamster lung

    International Nuclear Information System (INIS)

    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

  7. Propagation of Asian isolates of canine distemper virus (CDV in hamster cell lines

    Directory of Open Access Journals (Sweden)

    Yamaguchi Ryoji

    2009-10-01

    Full Text Available Abstract Backgrounds The aim of this study was to confirm the propagation of various canine distemper viruses (CDV in hamster cell lines of HmLu and BHK, since only a little is known about the possibility of propagation of CDV in rodent cells irrespective of their epidemiological importance. Methods The growth of CDV in hamster cell lines was monitored by titration using Vero.dogSLAMtag (Vero-DST cells that had been proven to be susceptible to almost all field isolates of CDV, with the preparations of cell-free and cell-associated virus from the cultures infected with recent Asian isolates of CDV (13 strains and by observing the development of cytopathic effect (CPE in infected cultures of hamster cell lines. Results Eleven of 13 strains grew in HmLu cells, and 12 of 13 strains grew in BHK cells with apparent CPE of cell fusion in the late stage of infection. Two strains and a strain of Asia 1 group could not grow in HmLu cells and BHK cells, respectively. Conclusion The present study demonstrates at the first time that hamster cell lines can propagate the majority of Asian field isolates of CDV. The usage of two hamster cell lines suggested to be useful to characterize the field isolates biologically.

  8. The Influence of Red Wine on Lipid of Golden Hamsters Plasma

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-ying; LI Hua; WANG Hua; YUAN Chun-long; XIE Ren-ming

    2007-01-01

    This experiment was conducted on 50 male golden hamsters, which were divided into five groups. Each group contained 10 hamsters: red wine group, alcohol-free red wine group, alcohol group, hyperlipidemia group, and control group. During the four-week regime, all the hamsters were fed with a high cholesterol diet, except the control group. After completion of the trial, the plasma lipid levels and lipid peroxidation contents were determined in the golden hamsters, and the morphological variation in liver cells was investigated with electron microscopy. The results showed that concentrations of TC and TG in red wine, alcohol-free red wine, and alcohol groups had decreased dramatically. Compared with the hyperlipidemia group, the levels of LDL-C had significantly decreased in other groups, but not the HDL-C. Consumption of red wine,alcohol-free red wine, and alcohol, had no significant effects on Apo A1 and Apo B. Red wine, alcohol-free red wine, and alcohol significantly decreased the contents of MDA in hamsters. The experiment demonstrated that red wine could ameliorate the incidence of atherosclerosis (AS) via reducing serum TC, TG, LDL-C, and the compounds in red wine had synergic effects.

  9. Thermogenin amount and activity in hamster brown fat mitochondria: effect of cold acclimation

    Energy Technology Data Exchange (ETDEWEB)

    Sundin, U.; Moore, G.; Nedergaard, J.; Cannon, B.

    1987-05-01

    To investigate the acclimation process in a hibernator, four different parameters of thermogenin amount and activity were investigated in brown adipose tissue mitochondria from cold-exposed and cold-acclimated Syrian hamsters. Hamsters, which are hibernators, have been considered to be primed for thermogenesis and thus not to show cold-acclimation effects, but here a significant increase in (/sup 3/H)GDP-binding capacity was observed, and this increase was paralleled by an increase in thermogenin antigen amount, as measured in an enzyme-linked immunosorbent assay. The transient nature of the effect of cold exposure on (/sup 3/H)GDP binding, characteristically observed with rat mitochondria, was not observed with hamster mitochondria, and the increase in (/sup 3/H)GDP binding occurred without a change in the dissociation constant. The increase in thermogenin amount was paralleled by an increase both in GDP-sensitive Cl/sup -/ permeability of the mitochondria and in GDP-sensitive respiration. It was established that it is the maximal activity of thermogenin that is rate limiting for thermogenesis in isolated mitochondria, provided that an optimal substrate is used (such as palmitoyl carnitine). Cold acclimation also increased the total amount of mitochondria in the tissue, leading totally to a sixfold increase in thermogenin content of the hamster. It is concluded that hamsters show the expected physiological, pharmacological, and biochemical signs of cold acclimation.

  10. Thermogenin amount and activity in hamster brown fat mitochondria: effect of cold acclimation

    International Nuclear Information System (INIS)

    To investigate the acclimation process in a hibernator, four different parameters of thermogenin amount and activity were investigated in brown adipose tissue mitochondria from cold-exposed and cold-acclimated Syrian hamsters. Hamsters, which are hibernators, have been considered to be primed for thermogenesis and thus not to show cold-acclimation effects, but here a significant increase in [3H]GDP-binding capacity was observed, and this increase was paralleled by an increase in thermogenin antigen amount, as measured in an enzyme-linked immunosorbent assay. The transient nature of the effect of cold exposure on [3H]GDP binding, characteristically observed with rat mitochondria, was not observed with hamster mitochondria, and the increase in [3H]GDP binding occurred without a change in the dissociation constant. The increase in thermogenin amount was paralleled by an increase both in GDP-sensitive Cl- permeability of the mitochondria and in GDP-sensitive respiration. It was established that it is the maximal activity of thermogenin that is rate limiting for thermogenesis in isolated mitochondria, provided that an optimal substrate is used (such as palmitoyl carnitine). Cold acclimation also increased the total amount of mitochondria in the tissue, leading totally to a sixfold increase in thermogenin content of the hamster. It is concluded that hamsters show the expected physiological, pharmacological, and biochemical signs of cold acclimation

  11. Effects of short photoperiod on energy intake, thermogenesis, and reproduction in desert hamsters (Phodopus roborovskii).

    Science.gov (United States)

    Zhang, Xueying; Zhao, Zhijun; Vasilieva, Nina; Khrushchova, Anastasia; Wang, Dehua

    2015-03-01

    Desert hamsters (Phodopus roborovskii) are the least known species in the genus Phodopus with respect to ecology and physiology, and deserve scientific attention, particularly because of their small body size. Here, the responses of energy metabolism and reproductive function to short photoperiods in desert hamsters were investigated. Male and female desert hamsters were acclimated to either long day (LD) (L:D 16:8 h) or short day (SD) photoperiods (L:D 8:16 h) for three months, and then the females were transferred back to an LD photoperiod for a further five months, while at the end of the SD acclimation the males were killed and measurements were taken for serum leptin as well as molecular markers for thermogenesis. We found that like the other two species from the genus Phodopus, the desert hamsters under SD decreased body mass, increased adaptive thermogenesis as indicated by elevated mitochondrial protein content and uncoupling protein-1 content in brown adipose tissue, and suppressed reproduction compared to those under LD. However, different from the other two species, desert hamsters did not show any differences in energy intake or serum leptin concentration between LD and SD. These data suggest that different species from the same genus respond in different ways to the environmental signals, and the desert adapted species are not as sensitive to change in photoperiod as the other two species. PMID:25311843

  12. The Fibroblast Growth Factor signaling pathway

    OpenAIRE

    Ornitz, David M.; Itoh, Nobuyuki

    2015-01-01

    The signaling component of the mammalian Fibroblast Growth Factor (FGF) family is comprised of eighteen secreted proteins that interact with four signaling tyrosine kinase FGF receptors (FGFRs). Interaction of FGF ligands with their signaling receptors is regulated by protein or proteoglycan cofactors and by extracellular binding proteins. Activated FGFRs phosphorylate specific tyrosine residues that mediate interaction with cytosolic adaptor proteins and the RAS-MAPK, PI3K-AKT, PLCγ, and STA...

  13. Expression profiles of craniosynostosis-derived fibroblasts.

    OpenAIRE

    Carinci, Francesco; Bodo, Maria; Tosi, Lara; Francioso, Francesca; Evangelisti, Rita; Pezzetti, Furio; Scapoli, Luca; Martinelli, Marcella; Baroni, Tiziano; Stabellini, Giordano; Carinci, Paolo; Bellucci, Catia; Lilli, Cinzia; Volinia, Stefano

    2002-01-01

    BACKGROUND: Craniosynostosis syndromes, a group of connective disorders characterized by abnormalities in vault osteogenesis and premature fusion of bone sutures, are associated with point mutations in FGF receptor family members. The cellular phenotype is characterized by abnormal extracellular matrix turnover. MATERIAL AND METHODS: We used primary cultures of periosteal fibroblasts derived from two different craniosynostosis syndromes, the Apert and Crouzon syndromes. The FGFR2 third immuno...

  14. Pre-existing Immunity and Passive Immunity to Adenovirus 5 Prevents Toxicity Caused by an Oncolytic Adenovirus Vector in the Syrian Hamster Model

    OpenAIRE

    Dhar, Debanjan; Spencer, Jacqueline F.; Toth, Karoly; Wold, William SM

    2009-01-01

    We have used Syrian hamsters to examine the role of pre-existing immunity to adenovirus (Ad) 5 in the toxicity of the oncolytic Ad vector INGN 007. Groups of hamsters were or were not immunized with Ad5. Half the hamsters were immunosuppressed using cyclophosphamide (CP), then injected intravenously (i.v.) with 3× the maximum tolerated dose (MTD) of INGN 007 (in immunocompetent hamsters), and toxicity and vector replication in the liver were quantitated. In nonimmunized immunocompetent hamste...

  15. Cancer exosomes trigger fibroblast to myofibroblast differentiation.

    Science.gov (United States)

    Webber, Jason; Steadman, Robert; Mason, Malcolm D; Tabi, Zsuzsanna; Clayton, Aled

    2010-12-01

    There is a growing interest in the cell-cell communication roles in cancer mediated by secreted vesicles termed exosomes. In this study, we examined whether exosomes produced by cancer cells could transmit information to normal stromal fibroblasts and trigger a cellular response. We found that some cancer-derived exosomes could trigger elevated α-smooth muscle actin expression and other changes consistent with the process of fibroblast differentiation into myofibroblasts. We show that TGF-β is expressed at the exosome surface in association with the transmembrane proteoglycan betaglycan. Although existing in a latent state, this complex was fully functional in eliciting SMAD-dependent signaling. Inhibiting either signaling or betaglycan expression attenuated differentiation. While the kinetics and overall magnitude of the response were similar to that achieved with soluble TGF-β, we identified important qualitative differences unique to the exosomal route of TGF-β delivery, as exemplified by a significant elevation in fibroblast FGF2 production. This hitherto unknown trigger for instigating cellular differentiation in a distinctive manner has major implications for mechanisms underlying cancer-recruited stroma, fibrotic diseases, and wound-healing responses. PMID:21098712

  16. Gene discovery in the hamster: a comparative genomics approach for gene annotation by sequencing of hamster testis cDNAs

    Directory of Open Access Journals (Sweden)

    Khan Shafiq A

    2003-06-01

    Full Text Available Abstract Background Complete genome annotation will likely be achieved through a combination of computer-based analysis of available genome sequences combined with direct experimental characterization of expressed regions of individual genomes. We have utilized a comparative genomics approach involving the sequencing of randomly selected hamster testis cDNAs to begin to identify genes not previously annotated on the human, mouse, rat and Fugu (pufferfish genomes. Results 735 distinct sequences were analyzed for their relatedness to known sequences in public databases. Eight of these sequences were derived from previously unidentified genes and expression of these genes in testis was confirmed by Northern blotting. The genomic locations of each sequence were mapped in human, mouse, rat and pufferfish, where applicable, and the structure of their cognate genes was derived using computer-based predictions, genomic comparisons and analysis of uncharacterized cDNA sequences from human and macaque. Conclusion The use of a comparative genomics approach resulted in the identification of eight cDNAs that correspond to previously uncharacterized genes in the human genome. The proteins encoded by these genes included a new member of the kinesin superfamily, a SET/MYND-domain protein, and six proteins for which no specific function could be predicted. Each gene was expressed primarily in testis, suggesting that they may play roles in the development and/or function of testicular cells.

  17. Alteration of Skin Properties with Autologous Dermal Fibroblasts

    Directory of Open Access Journals (Sweden)

    Rajesh L. Thangapazham

    2014-05-01

    Full Text Available Dermal fibroblasts are mesenchymal cells found between the skin epidermis and subcutaneous tissue. They are primarily responsible for synthesizing collagen and glycosaminoglycans; components of extracellular matrix supporting the structural integrity of the skin. Dermal fibroblasts play a pivotal role in cutaneous wound healing and skin repair. Preclinical studies suggest wider applications of dermal fibroblasts ranging from skin based indications to non-skin tissue regeneration in tendon repair. One clinical application for autologous dermal fibroblasts has been approved by the Food and Drug Administration (FDA while others are in preclinical development or various stages of regulatory approval. In this context, we outline the role of fibroblasts in wound healing and discuss recent advances and the current development pipeline for cellular therapies using autologous dermal fibroblasts. The microanatomic and phenotypic differences of fibroblasts occupying particular locations within the skin are reviewed, emphasizing the therapeutic relevance of attributes exhibited by subpopulations of fibroblasts. Special focus is provided to fibroblast characteristics that define regional differences in skin, including the thick and hairless skin of the palms and soles as compared to hair-bearing skin. This regional specificity and functional identity of fibroblasts provides another platform for developing regional skin applications such as the induction of hair follicles in bald scalp or alteration of the phenotype of stump skin in amputees to better support their prosthetic devices.

  18. Adapting to alcohol: Dwarf hamster (Phodopus campbelli) ethanol consumption, sensitivity, and hoard fermentation.

    Science.gov (United States)

    Lupfer, Gwen; Murphy, Eric S; Merculieff, Zoe; Radcliffe, Kori; Duddleston, Khrystyne N

    2015-06-01

    Ethanol consumption and sensitivity in many species are influenced by the frequency with which ethanol is encountered in their niches. In Experiment 1, dwarf hamsters (Phodopus campbelli) with ad libitum access to food and water consumed high amounts of unsweetened alcohol solutions. Their consumption of 15%, but not 30%, ethanol was reduced when they were fed a high-fat diet; a high carbohydrate diet did not affect ethanol consumption. In Experiment 2, intraperitoneal injections of ethanol caused significant dose-related motor impairment. Much larger doses administered orally, however, had no effect. In Experiment 3, ryegrass seeds, a common food source for wild dwarf hamsters, supported ethanol fermentation. Results of these experiments suggest that dwarf hamsters may have adapted to consume foods in which ethanol production naturally occurs. PMID:25712038

  19. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  20. Stressors, including social conflict, decrease plasma prolactin in male golden hamsters.

    Science.gov (United States)

    Huhman, K L; Mougey, E H; Moore, T O; Meyerhoff, J L

    1995-12-01

    Following exposure to a stressor, plasma prolactin (PRL) rises in most species. The purpose of the present study was to examine the effect of social conflict or of footshock stress on PRL responsiveness in male Syrian hamsters. Contrary to expectations, PRL was significantly lower in subordinate hamsters than in their dominant opponents or in controls following one, five, or nine exposures to social conflict. Similarly, PRL was reduced in hamsters subjected to a mild footshock stressor. By contrast, adrenocorticotropin, another stress-responsive hormone, was elevated following exposure to each of these stressors. We also demonstrate that PRL release is inhibited by dopamine as it is in other species by showing that there is a dose-dependent increase in PRL release following treatment with the dopamine receptor blocker, domperidone. PMID:8748515