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alterations in the metabolism of [6-h3] galactose in chinese hamster ovary cells at 20 degrees c compared to 37 degrees c. 20133246628
antimutagenic action of methionine in chinese hamster fibroblasts: an opposite of methionine mutagenicity.serially propagated fibroblast clones were treated with 25-mm methionine and a thioguanine resistance assay was performed at each passage to measure mutagenesis at the hgprt locus. the spontaneous frequency of thioguanine resistant mutants before treatment was less than 5 x 10(-6) in four clones and 22 x 10(-6) in one clone. these values dropped 10- to 100-fold and remained so until the methionine was withdrawn, then returned to, or overshot, the initial values. it is proposed that these fibrobl ...20133178160
[proteinase participation in chromosome radiation damage. research on the action of phenylmethylsulfonyl fluoride].phenylmethylsulfonyl fluoride, a chromatin proteinase inhibitor, caused a nearly twofold diminution of the cytogenetic injury and a twofold increase in the rate of dna repair in gamma-irradiated (3-15 gy) chinese hamster fibroblasts. the effect of the inhibitor was mainly exhibited by a rapidly repaired (for 15-20 min) component of the cytogenetic damage. a simultaneous treatment with phenylmethylsulfonyl fluoride and nicotinamide did not influence the effect of the proteinase inhibitor under st ...20132969597
effects of diesel exhaust particles on chromosome aberration, sister chromatid exchange and morphological transformation in cultured mammalian cells.the ability of diesel exhaust particles (diesel tar) from light-duty (ld) and heavy-duty (hd) engines to induce chromosome aberrations, sister chromatid exchanges (sces) and morphological transformations is examined. chinese hamster v79 cells were treated with ld and hd diesel tar for 3 h in order to analyze chromosome aberrations and sces. balb/c 3t3 cells were used for the morphological transformation test. ld tar induced significant numbers of chromosome aberrations, whereas hd did not. both ...20132460218
heat sensitization to cisplatin in two cell lines with different drug sensitivities.heat sensitization to cisplatin was studied in drug-sensitive chinese hamster fibroblast (ch) and inherently drug-resistant hamster kidney (hak) cells. under normothermic conditions the slopes of the survival curves differed by a factor of 3.6, while the cellular uptake was higher in ch cells by a factor of 3. when heat and drug treatment were given simultaneously, both effects were increased in ch and hak cells: thermal enhancement factors at 43 degrees c were 5.5 (ch) and 2.9 (hak) for cytotox ...20132299237
[the uv sensitivity of the bromodeoxyuridine-substituted chromosomes in the chinese hamster].chinese hamster cells with chromosomes differently substituted for budr (tt-tt, tt-tb, tb-tb, tb-bb, where t is thymidine containing chromatid and b is budr substituted chromatid) were exposed to uv-light in phase g2 and chromosome aberrations (mainly chromatid breaks) were analysed. breaks frequency per chromosome was proportional to budr content. no breaks were found in tt-tt chromosomes. the frequency of breaks per tb chromatid was similar with tt-tb and tb-bb chromosomes. in tb-bb chromosome ...20132349386
potentiation of bleomycin cytotoxicity by polyhydric alcohols.the cytotoxicity of bleomycin (blm) toward chinese hamster v79 and murine leukemia l1210 was extraordinarily potentiated in the presence of glycerol. the synergistic effect of glycerol emerged in combinations with blm analogs (peplomycin and libromycin) as well, but not with other cytotoxic drugs such as adriamycin, neocarzinostatin, paraquat, hydrogen peroxide, and n-methyl-n-nitrosourea. the cytotoxicity of blm and its analogs was potentiated by some polyhydric alcohols as intensely as by glyc ...20131692198
modification of intracellular ph and thermotolerance development by amiloride.the intracellular ph (phi) of cells heated at 45.0 degrees c in the presence or absence of amiloride and in choline chloride substituted sodium-free medium was measured with flow cytometry using the ph sensitive dye, carboxy-seminaphthorhodafluor (snarf-1). chinese hamster ovary (cho) cells at ph 7.3 and low-ph-resistant (phv2) cells at ph 6.6 were studied. bimodal population distributions of phi were obtained for both cho and phv2 cells following a treatment in which cells were heated 10 min at ...20137594805
reaction kinetics for nitrosation of cysteine and glutathione in aerobic nitric oxide solutions at neutral ph. insights into the fate and physiological effects of intermediates generated in the no/o2 reaction.the critical regulatory function of nitric oxide (no) in many physiologic processes is well established. however, in an aerobic aqueous environment no is known to generate one or more reactive and potentially toxic nitrogen oxide (nox) metabolites. this has led to the speculation that mechanisms must exist in vivo by which these reactive intermediates are detoxified, although the nature of these mechanisms has yet to be elucidated. this report demonstrates that among the primary bioorganic produ ...20137981416
mutation and repair induced by the carcinogen 2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine (n-oh-phip) in the dihydrofolate reductase gene of chinese hamster ovary cells and conformational modeling of the dg-c8-phip adduct in dna.three experiments using 20 microm 2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine (n-oh-phip) were performed to induce mutations in the dihydrofolate reductase (dhfr) gene of a hemizygous chinese hamster ovary (cho) cell line (ua21). metabolized forms of this chemical primarily bind at the c-8 position of guanine in dna. in total, 21 independent induced mutants were isolated and 20 were characterized. dna sequencing showed that the preferred mutation type found in 75% of the induced dhf ...20138199311
heat protection by deuterium oxide of heat sensitive and wild-type chinese hamster ovary cells.the ability of deuterium oxide (d2o) to protect a heat-sensitive and thermotolerance-impaired chinese hamster ovary (cho) mutant cell line, hs-36 (harvey and bedford 1988), from heat killing was examined and compared to the parent cho 10b cell line (wt). both non-thermotolerant (nt) and thermotolerant (tt) g1 populations were examined. d2o differentially protected the nt cell lines from heat killing, with thermal protection ratios (d0) of 2 x 5 and 4 x 3 for hs-36 and wt cells, respectively. d2o ...20138144990
a computer model for intracellular ph regulation in chinese hamster ovary cells.a single-cell model for chinese hamster ovary (cho) cells has been extended to study the regulation of intracellular ph. this model provides for the first time a direct mechanistic linkage between intracellular ph control and cellular metabolism. among the known mechanisms that regulate and disturb phi, the na/h antiport, effect of lactate and ammonia, proton leakage, and external ph have been included in the model. the ability of the model to predict both steady-state and transient phi has been ...20137764066
bicarbonate-dependent proton extrusion in chinese hamster ovary (cho) cells adapted to growth at ph 6.7.a cho cell model is described for in vitro studies of the mechanisms underlying heat resistance in cells adapted to growth in acidic environments. adaptation is defined as a loss of ph 6.7-induced sensitization to 42.0 degrees c cytotoxicity and it is accompanied with an elevation of steady-state intracellular ph (phi). cho cells cultured between 75 and 100 days at ph 6.7 became fully adapted (6.7g cells), and the adapted phenotype was maintained for at least 100 additional days of culture at ph ...20139222815
cell cycle analysis of synchronized chinese hamster cells using bromodeoxyuridine labeling and flow cytometry.chinese hamster ovary cells were synchronized into purified populations of viable g1-, s-, g2-, and m-phase cells by a combination of methods, including growth arrest, aphidicolin block, cell cycle progression, mitotic shake-off, and centrifugal elutriation. the dna content and bromodeoxyuridine (brdurd) labeling index were measured in each purified fraction by dual-parameter flow cytometry. the cell cycle distributions determined from the dna measurements alone (single parameter) were compared ...20138528504
mutagenic effect of mercury (ii) in eukaryotic cells.acute exposure of kb and chinese hamster ovary cells (as52) to low concentrations of mercury (ii) results in a dose dependent binding of mercury to dna. this binding of mercury (ii) to the dna occurs at concentrations of mercury that have little if any effect on glutatione levels or on superoxide dismutase activity. mutational studies with as52 cells demonstrated that concentrations (0.1 to 0.4 microm) of mercury (ii) which were not cytotoxic caused an increase (1.7 to 3.1) in the frequency of m ...20137893984
protocol for freezing thermotolerant cells and maintaining thermotolerance following thawing.two independent laboratories have demonstrated that suspension-grown, chinese hamster ovary (cho) cells can be made thermotolerant, frozen and subsequently thawed such that they still express thermotolerance. thermotolerance was determined as the ability to protect cells against hyperthermic cell killing (colony formation assay) and the ability to reduce protein aggregation within the nuclei of heated cells. cells were frozen either following development of full or partial thermotolerance. in th ...20137636325
glycosylation of cho-derived recombinant tpa produced under elevated pco2.carbon dioxide is a metabolic byproduct of mammalian cell metabolism that can accumulate in poorly ventilated cultures. a buildup of co2 at constant ph will be accompanied by an increase in medium osmolality. we have examined the glycosylation of tissue plasminogen activator (tpa) produced under serum-free conditions by recombinant chinese hamster ovary (cho) cells (mt2-1-8 cell line) in response to elevated pco2 at constant or elevated osmolality. the proportion of sialic acids comprising n-gly ...20139190082
wr-1065, an active metabolite of the cytoprotector amifostine, affects phosphorylation of topoisomerase ii alpha leading to changes in enzyme activity and cell cycle progression in cho aa8 cells.the effects of wr-1065 (2-((aminopropyl)amino)ethanethiol) on cell cycle progression, topoisomerase (topo) ii alpha activity, and topo ii alpha phosphorylation in chinese hamster ovary (cho) cells have been investigated. exposure of cho cells to 0.4 microm of wr-1065 for 30 min did not effect cell cycle progression nor topo ii alpha activity and phosphorylation status. however, concentrations ranging from 4 microm to 4 mm were equally effective in significantly altering these three end points. c ...20139451419
effects of ammonium and lactate on growth and metabolism of a recombinant chinese hamster ovary cell culture.a chinese hamster ovary (cho) cell line producing a recombinant glycoprotein was cultured in batch mode with different initial concentrations of ammonium chloride (0-10 mm), sodium lactate (0-60 mm), or sodium chloride (0-60 mm). high ammonium concentrations did not inhibit cell growth and productivity or glucose and glutamine consumption. in contrast, specific ammonia and alanine production decreased by 55% and 40%, respectively. there were also significant increases in specific aspartate and g ...20139336989
control of long-term perfusion chinese hamster ovary cell culture by glucose auxostat.the strategies for control of the feed rate in high-density perfusion cultures of animal cells are limited to several simple schemes. while in an industrial environment simplicity is seen as a major advantage, the need for more elaborate closed-loop control methods that can improve process stability in long-term continuous cultures is also well understood. what has prevented the application of the advanced control strategies known from theory is the lack of reliable real-time information that ca ...20138845100
potential chemoprotectant activity of mechanism-based glycosidase inhibitors against ricin toxicity in chinese hamster ovary and macrophage j774a.1 cell cultures.the abilities of the triacetylated galacto- and gluco-derivatives of 2-deoxy-2-fluoro-d-pyranosyl fluoride as well as alpha- and beta-n-bromoacetyl-d-galactopyranosylamine to inhibit the cytotoxicity of ricin in vitro in macrophage j774a.1 and chinese hamster ovary (cho) cell lines were determined. leakage of lactate dehydrogenase (ldh) and aspartate aminotransferase (ast) from the cells into the culture media were used as indicators of ricin cytotoxicity. the potential chemoprotectants were use ...20138821675
potential chemoprotectant activity of 3'-azido-3'-deoxythymidine (azt) and 2',3'-dideoxycytidine (ddc) against ricin toxicity in chinese hamster ovary and macrophage j774a.1 cell cultures.the protein toxin ricin is one of the most toxic substances known. no specific chemoprotective agents are available against ricin or similar protein toxins. previous investigations have suggested that deoxynucleoside analogs may be effective in decreasing the toxicity of ricin. we have therefore examined the effects of 3'-azido-3'-deoxythymidine (azt) and 2',3'-dideoxycytidine (ddc) in decreasing the cytotoxicity of ricin in j774a.1 macrophage and chinese hamster ovary (cho) cells in culture by ...20138821674
effect of acetaldehyde generated from ethanol by adh-transfected cho cells on their membrane fatty acid profiles.ethanol has been previously shown to reduce the unsaturated fatty acid content of cell membranes. it is not known, however, if the observed deleterious effects are due to ethanol itself or its metabolite, acetaldehyde. the present study was undertaken to assess the effect of acetaldehyde produced from ethanol by alcohol-deyhdrogenase-transfected chinese hamster ovary cells on the membrane lipids and the lipid peroxidation measured by free and bound malondialdehyde (mda). the effects of ethanol a ...20138949957
can a mixed damage interfere with dna-protein cross-links repair?some photochemical and photobiological properties of 4,5',8-trimethylpsoralen (tmp) have been studied in comparison with 1,4,6,8-tetramethyl-2h-furo[2,3-h]quinolin-2 one (fq) and 8-methoxypsoralen (8-mop). tmp and fq can photobind to mammalian cell dna in vivo, by uva irradiation, forming dna-protein cross-links (dpc), but only tmp shows a strong capacity of inducing interstrand cross-links (isc). the mechanism of dpc formation was studied using the double irradiation method in chinese hamster o ...201312067500
effects of cloned gene dosage on the response of recombinant cho cells to hyperosmotic pressure in regard to cell growth and antibody production.the effect of cloned gene dosage on growth and product formation under hyperosmotic conditions has been studied using recombinant chinese hamster ovary (rcho) cell lines producing chimeric antibody. batch cultures of four rcho cell lines carrying different numbers of antibody gene copies were carried out using the hyperosmolar medium. depending on cloned gene dosage, hyperosmotic pressure decreased specific growth rate (mu) and increased specific antibody productivity (q(ab)) to a different degr ...201311735431
in vitro and in vivo inhibition of telomerase activity from chinese hamster v79 cells.while studying the inhibition of telomerase activity in chinese hamster v79 cells using polymerase chain reaction (pcr) based telomeric repeat amplification protocol (trap) assay, we had earlier observed that 7-deaza deoxy guanosine triphosphate (7-deaza dgtp) and oligonucleotide (ttaggg)4 inhibited telomerase activity in vitro. in the present study, we report inhibition of telomerase activity by modified base 7-deaza deoxy adenosine triphosphate (7-deaza datp) and phosphorothioate ttaggg (ps-tt ...201311563329
the drag test: an assay for detection of genotoxic damage.a high throughput assay (the drag test) is described, which could be a useful tool for the detection of repairable dna adducts, and which is based on the inhibition of the growth of dna repair-deficient chinese hamster ovary (cho) cells. the cytotoxicity of a test substance towards dna repair-deficient cho cell lines is compared with the corresponding cytotoxicity in the parental wild-type cho cell line (aa8). a more pronounced toxicity toward a dna repair-deficient cell line is interpreted as b ...201311387020
quercetin sensitizes cells in a tumour-like low ph environment to hyperthermia.quercetin has been shown to act as a hyperthermia sensitizer by inhibiting the synthesis of heat shock protein 70 (hsp70) in a variety of tumour cell lines. it is most effective under conditions of low ph. this study was designed to test the hypothesis that quercetin suppresses thermotolerance development in cells adapted to growth at low ph and renders them as responsive as acutely acidified cells to hyperthermia-induced cytotoxicity. chinese hamster ovarian carcinoma cells (ovca) were exposed ...201312944166
apoptosis induced by different doses of caffeine on chinese hamster ovary cells.caffeine has been investigated for its potential mutagenic activity to bacteria, fungi and mammalian cells in culture, and at high concentrations it is also an inducer of apoptosis. caffeine can exert acute cellular toxicity, including inhibition of cell growth and cell death, in chinese hamster ovary cells. the aim of this study was to evaluate the cell survival and apoptotic or non-apoptotic effects of caffeine to different concentrations in chinese hamster ovary cells (cho-k1). these effects ...201312884404
antimutagenicity of sodium selenite in chinese hamster v79 cells exposed to azoxymethane, methylmethansulphonate and hydrogen peroxide.in the last 10 years, there is an increasing interest in selenium (se) because of its environmental, biological, and toxicological importance, and in particular, because of its antioxidant properties. however, inspite of extensive studies, the optimal concentration of se to be used for its beneficial effects in not yet known. in addition, the mechanisms of se antioxidant property require further study. we report on the effects of various mutagens/carcinogens such as azoxymethane, methylmethanesu ...201312628500
effect of doxycycline-regulated erp57 expression on specific thrombopoietin productivity of recombinant cho cells.in an attempt to increase the specific thrombopoietin (tpo) productivity (q(tpo)) of recombinant chinese hamster ovary (rcho) cells (tpo-33), the effect of expression level of erp57, an isoform of protein disulfide isomerase, on q(tpo) was investigated. to regulate erp57 expression level, the tet-off system was first introduced in tpo-33 cells and stable tet-off cells (tpo-33-tet-off) were screened by the luciferase assay. the rcho cells with a doxycycline-regulated erp57 expression system (tpo- ...201312573023
arsenic(iii), but not antimony(iii), induces dna-protein crosslinks.antimony compounds are supposed to resemble to arsenicals in some toxicological features. comparative investigations with antimony and arsenic were performed to collect data on the genotoxicity of antimony, on which the knowledge is scarce. in comparison to trivalent arsenic, trivalent antimony proved to be five times less cytotoxic in the neutral red assay and one order of magnitude less genotoxic in the cytokinesis-block micronucleus test using v79 chinese hamster cells. the data obtained in t ...20139891475
hyperthermia, cyclosporine a and melphalan cytotoxicity and transport in multidrug resistant cells.the ability of hyperthermia and cyclosporine a to modulate melphalan cytotoxicity and transport processes was investigated in a pleiotropic mdr chinese hamster ovary cell line (ch(r)c5) and in the drug-sensitive parent line (auxb1). cyclosporine a increased cytotoxicity of melphalan in mdr cells, but not in drug-sensitive cells. in mdr cells, hyperthermia caused marked enhancement of melphalan cytotoxicity when cyclosporine a was present. the increased melphalan cytotoxicity in mdr cells was acc ...20139886664
effects of thiols on topoisomerase-ii alpha activity and cell cycle progression.thiol containing compounds exhibiting antioxidant properties are currently being evaluated for use in cytoprotection and chemoprevention. many of these have also been found to be effective in inhibiting cell cycle progression and cellular proliferation. n-acetyl-l-cysteine (l-nac), along with its nonmetabolically active stereoisomer n-acetyl-d-cysteine (d-nac), together with captopril and dithiothreitol (dtt) were investigated to assess their effects on cell cycle progression as determined by fl ...20139925989
higher productivity of growth-arrested chinese hamster ovary cells expressing the cyclin-dependent kinase inhibitor p27.we constructed stable chinese hamster ovary (cho) cell lines which conditionally and coordinately express the model product gene secreted alkaline phosphatase (seap) and one of the cytostatic genes p21, p27, and p53175p, a p53 mutant deficient in apoptotic but not cell-cycle arrest function. the use of dicistronic expression technology allowed the conditional expression of the model product gene and the cytostatic gene in a coordinated fashion from a single expression unit under the control of t ...20139758659
increased t-pa yields using ultrafiltration of an inhibitory product from cho fed-batch culture.fed-batch operation for the production of t-pa using chinese hamster ovary (cho) cells was optimized using serial and parallel experimentation. the feed, an isotonic concentrate, was improved to obtain 2- to 2.5-fold increases in integrated viable cell days versus batch. with a low glucose inoculum train, the viability index was further increased up to 4.5-fold. hydrolysates were substituted for the amino acid portion of the concentrate with no significant change in fed-batch results. the concen ...201311027171
osmoprotective effect of glycine betaine on thrombopoietin production in hyperosmotic chinese hamster ovary cell culture: clonal variations.when 23 recombinant chinese hamster ovary (rcho) cell clones were cultivated in hyperosmolar medium resulting from nacl addition (533 mosm/kg), their specific thrombopoietin (tpo) productivity (q(tpo)) was increased. however, due to depressed cell growth at elevated osmolality, no enhancement in the maximum tpo titer was made in batch cultures of all 23 clones. to test the feasibility of using glycine betaine, known as a strong osmoprotective compound, for improved tpo production in hyperosmotic ...201311027169
measurement and control of dissolved carbon dioxide in mammalian cell culture processes using an in situ fiber optic chemical sensor.at high viable cell concentrations in large-scale mammalian cell culture processes, the accumulation of dissolved carbon dioxide (dco(2), typically quantified as an equilibrium gas-phase concentration) becomes problematic as a result of low co(2) removal rates at reduced surface-to-volume ratios. high dco(2) concentrations have previously been shown to inhibit cell growth and product formation in mammalian cells and to alter the glycosylation pattern of recombinant proteins. therefore, reliable ...201311027168
amplified gene location in chromosomal dna affected recombinant protein production and stability of amplified genes.previously, we established an easy and quick construction method for obtaining a stable and highly productive gene-amplified recombinant chinese hamster ovary (cho) cell line. with a gradual increase in methotrexate (mtx) concentration, gene-amplified cell pools had high and stable specific growth and production rates. moreover, the phenotype of gene-amplified cells seemed to be affected by the location of the amplified gene in chromosomal dna. we suspected that various kinds of gene-amplified c ...201311027161
the growth factor inhibitor suramin reduces apoptosis and cell aggregation in protein-free cho cell batch cultures.we have previously shown that chinese hamster ovary (cho) cells capable of growing in medium free of exogenous proteins die by apoptosis during all stages of a batch culture (zanghi et al., 1999). on the basis of the hypothesis that extracellular death factors might be important in apoptosis under these conditions, we examined the effect of the growth factor inhibitor and antitumor agent suramin on cho cell growth and apoptosis in serum-free culture. suramin protected against apoptosis during ex ...201310835230
improvement of cho cell culture medium formulation: simultaneous substitution of glucose and glutamine.the formulation of the culture medium for a chinese hamster ovary (cho) cell line has been investigated in terms of the simultaneous replacement of glucose and glutamine, the most commonly employed carbon and nitrogen sources, pursuing the objective of achieving a more efficient use of these compounds, simultaneously avoiding the accumulation of lactate and ammonium in the medium. the key factor in this process is the selection of compounds that are slowly metabolized. among the different compou ...201310662492
animal cell mutants defective in glycosaminoglycan biosynthesis.we have obtained chinese hamster ovary cell mutants defective in the biosynthesis of glycosaminoglycans by screening replicate colonies immobilized on polyester cloth. depending upon the strain, the mutants accumulated less 35s-labeled glycosaminoglycans per microgram of cell protein by a factor of 6-60 compared to the wild type. some of the mutants incorporated [6-3h]glucosamine into glycosaminoglycans to the same extent as the wild type, suggesting that sulfate addition was specifically altere ...20133858816
enhancing effects of cytosine arabinoside on ethyl methanesulfonate-induced 6-thioguanine resistance mutations in chinese hamster v79 cells.we studied the synergistic enhancement effects of two chemicals which are different in their mechanism of action on dna in cells. the test chemicals used were ethyl methanesulfonate (ems) as an alkylating agent and cytosine arabinoside (ara-c) as an analogue of cytidine. for determination of mutagenesis we measured the induction of resistance to 6-thioguanine (6-tg) in chinese hamster v79 cells. ems had a strong mutagenic effect on v79 cells, but for ara-c the results were less clear. in this st ...20133574339
aneuploidy is not induced by ethanol during spermatogenesis in the chinese hamster.aneuploidy was scored in spermatogonial stages and at both meiotic divisions in male chinese hamsters exposed to alcohol in vivo. after light ether anesthetization, the animals were intubated (by gastric tube) with 1.5 ml of 12.5% ethanol, whereas controls were given 1.5 ml of distilled water. gonadectomy was performed 3.5-24 h after ethanol exposure. ethanol-dosed animals were obviously intoxicated, as evidenced by a rolling gait; serum alcohol levels in 10 animals that were tested peaked 1-2 h ...20133816304
studies on the mechanisms of the radiosensitizing and cytotoxic properties of rsu-1069 and its analogues.rsu 1069 is a substantially more efficient sensitizer than misonidazole when hypoxic chinese hamster v79 cells are irradiated in vitro at room temperature; such that for 0.5 mmol dm-3 sensitizer an er of 3.0 is obtained for rsu 1069 whereas an er of only 1.6 is obtained for misonidazole. however, when irradiation is done at 4 degrees c, the radiosensitization caused by rsu 1069 is reduced to a level close to that obtained with misonidazole, the action remaining unaltered at the lower temperature ...20133755712
differential effects of pre- and posttreatment of sodium arsenite on the genotoxicity of methyl methanesulfonate in chinese hamster ovary cells.pretreatment of sodium arsenite reduces hypoxanthine-guanine phosphoribosyltransferase mutagenicity and overcomes the inhibition of mitosis and cell proliferation but has no apparent effect on the cytotoxicity and clastogenicity in methyl methanesulfonate (mms)-treated chinese hamster ovary cells. posttreatment of sodium arsenite drastically increases the cytotoxicity, clastogenicity, hypoxanthine-guanine phosphoribosyltransferase mutagenicity, and inhibition of mitosis and cell proliferation in ...20133753897
verapamil hypersensitivity of vincristine resistant chinese hamster ovary cell lines.vincristine resistant cho cell lines, obtained by prolonged selection in semi-inhibitory drug concentrations show considerable hypersensitivity to verapamil. their d10 values are around 0.2 micrograms/ml compared to 23 micrograms/ml for unselected controls. reversion of vincristine resistance during growth in vincristine free medium is correlated with reversal of verapamil sensitivity indicating that the two aspects of the cells' phenotype have a common underlying cause. the rate of uptake of ca ...20133719706
cell surface glycoproteins of cho cells. i. internalization and rapid recycling.the major cell surface proteins of chinese hamster ovary (cho) cells have been investigated after reacting cells at 4 degrees c with the membrane-impermeant reagent, trinitrobenzenesulfonate (tnbs). immunoprecipitation and subsequent two-dimensional, sodium-dodecyl sulfate, polyacrylamide gel electrophoresis (sds-page) of proteins from derivatized cells that had been labelled previously with [3h]d-glucosamine or [3h]l-leucine showed that tnbs reacted with most of the high molecular weight (hmw) ...20133709690
[recovery from thermal damage of mammalian cells fixed by treatment with a hypertonic sodium chloride solution].the survival of chinese hamster cell v79-4 after hyperthermic treatment (42 degrees c, 40 minutes) in the exponential growth phase considerably increases with the duration of holding them in the growth medium at 37 degrees c before hypertonic salt treatment (1.5 m nacl, 15 minutes). the experimental data are interpreted as a recovery of mammalian cells from thermal lesions, whose lethal action manifests itself at high salt concentrations.20133672644
[localization of dihydrofolate reductase amplified genes in chinese hamster cells resistant to methotrexate].new sublines of bffr1 and bffr3 cells were obtained as a result of prolonged cultivation of chinese hamster cells of blld-ii-faf 28 line (clone 431) in the presence of increasing concentrations of methotrexate (mtx). the lines obtained were resistant to 200 and 300 mcm of mtx, respectively. amplification of the gene for dihydrofolate reductase (dhfr), similar to normal dhfr gene in restriction patterns, was proved by blot-hybridization of the resistant cells' dna with 32p-labeled plasmid dhfr-26 ...20133692154
absence of dna overreplication in chinese hamster cells incubated with inhibitors of dna synthesis.previous reports have suggested that transient inhibition of dna synthesis by chemicals or ultraviolet light causes some of the dna to replicate more than once in one cell cycle, i.e., that it induces overreplication of dna. the data that led to this suggestion were obtained from cesium chloride equilibrium density gradient analyses, in which cells were incubated with bromodeoxyuridine so that the dna synthesized after incubation with the inhibitor could be densitometrically separated from the d ...20133664465
antibody labelling and flow cytometric analysis of metaphase chromosomes reveals two discrete structural forms.metaphase chromosomes from cultured chinese hamster ovary cells were labelled in suspension with a monoclonal antibody to histone 2b, counterstained with propidium iodide (pi) and analysed by flow cytometry. contour plots of antibody binding (fitc fluorescence) against dna content (pi fluorescence) revealed two discrete forms of each individual chromosome, showing high and low levels of antibody binding respectively. the two types of chromosome were easily distinguishable by immunofluorescence m ...20133622080
effect of increase in ploidy on the activation of nucleolar organizer regions in chinese hamster ovary (cho) cells.the effect of increased ploidy on the activation of specific nucleolar organizer regions (nors) was examined by comparing the distribution and frequency of active nors in pseudodiploid chinese hamster ovary (cho) cells with a quasi-tetraploid hybrid line. active nors were identified on both unrearranged chromosomes and isochromosomes of the z group by silver staining. the increase in cell ploidy in the hybrid did not result in the complete inactivation of specific nors or the activation of a pre ...20133709688
mortality in two cohorts of welders exposed to high- and low-levels of hexavalent chromium.hexavalent chromium particles are generated in the welding of stainless steel. these particles have manifested a mutagenic action in bacterial test systems and produced chromosome aberrations in cultured chinese hamster cells. a cohort consisting of 234 welders working on stainless steel and exposed to high levels of chromium was selected. according to an earlier survey the hexavalent chromium exposure of such welders was often above 20 micrograms/m3. another cohort consisting of 208 railway tra ...20133616554
[lethal action of accelerated heavy ions on mammalian cells as affected by inhibitors of dna synthesis. a theoretical analysis].günter-schulz's model and the authors' own model were used to study the dependence of radiosensitivity (d0(-1)) of chinese hamster cells on linear energy transfer (let) upon irradiation in standard conditions and in the presence of dna synthesis inhibitors, arabinosylcytosine and hydroxyurea. a better agreement of the experimental and theoretical results was obtained using kozubek-krasavin's model than the model of günter and schulz.20133575666
effects of temperature, ph elevators, and energy production inhibitors on horseradish peroxidase transport through endocytic vesicles.we investigated the effects of reduced temperature, the ph elevators nh4cl, monensin, and hepes (n-2-hydroxy-ethylpiperazine-n'-2-ethanesulfonic acid) buffer, as well as the metabolic poisons naf/kcn on transport of the fluid phase pinocytic marker, horseradish peroxidase (hrp), to lysosomes in chinese hamster ovary (cho) cells. in cell fractionation experiments, these agents appeared to block hrp transit at specific point(s) from "early" to "late" (i.e., low to high density) prelysosomal vesicl ...20133571336
influence of pulsing electromagnetic field on the frequency of sister-chromatid exchanges in cultured mammalian cells.exposures of chinese hamster cells to pulsing electromagnetic field (pemf) with 0.18-2.5 mt did not influence the baseline frequency of sister-chromatid exchanges (sce). the results suggest that pemf with the magnetic intensity examined does not interfere with dna replication nor produce dna lesions, thereby leading to an increased frequency of sce.20133556530
effect of aging on the frequency of metaphase chromosome aberrations in the liver of the chinese hamster. 20134745474
the radiomimetic properties of a platinum drug.chip (cis-dichlorobis isopropylamine trans-dihydroxy platinum iv) is a second-generation platinum co-ordination complex which potentiates the effects of radiation. comparisons of the biological effects of chip and x rays upon chinese hamster (ovary) cells have shown similarities with respect to the shape of the dose-response curves, clone size distributions and perturbation of the cell cycle. unlike irradiated cells however, chip-treated cells showed no recovery from sublethal damage and no vari ...20133840711
changes in bleb formation following hyperthermia treatment of chinese hamster ovary cells.chinese hamster ovary cells in suspension cultures were heated for various times at 41.5, 43.5, and 45.5 degrees c, and quantitative determinations of microblebbing and macroblebbing of the cell membrane were performed for cells maintained at 4, 25, and 37 degrees c after hyperthermia. the percentage of cells with blebs following heating at 45.5 degrees c was dependent upon the duration of heating with increases from 40% for 5 min to 90% for 30 min. cells exposed to lower temperatures exhibited ...20133754340
a fractionated cell-free system for analysis of prophase nuclear disassembly.we describe a cell-free system in which a postribosomal supernatant (s140) from metaphase chinese hamster ovary (cho) cells induces prophase-like changes in isolated cho cell nuclei, including chromatin condensation, and nuclear envelope and lamina disassembly. these events are strongly promoted by gamma-s-atp and an atp-regenerating system, and do not take place with an s140 derived from g2-phase cells. the metaphase cell s140 also induces disassembly of an isolated nuclear lamina fraction that ...20133782291
abnormal mitotic spindle assembly and cytokinesis induced by d-limonene in cultured mammalian cells.d-limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. with the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to d-limonene and elucidate its, as yet unknown, mechanism of action. we reported here that d-limonene is toxic in v79 chinese hamster cells in a dose-dependent manner. moreover, to determine th ...201323913329
the desaturase opin17 from phytophthora infestans converts arachidonic acid to eicosapentaenoic acid in cho cells.we demonstrate the ability to increase the amount of eicosapentaenoic acid (epa, 20:5n-3) in mammalian cells using opin17 desaturase gene. this gene was codon optimized based on genomic sequence of δ17 from phytophthora infestans and introduced into chinese hamster ovary cells using liposome-mediated transfection protocol. reverse transcription polymerase chain reaction was utilized to evaluate co-expression of acgfp1 and opin17. our results indicate that the opin17 gene can be expressed in mamm ...201323912207
phototoxicity testing in vitro: evaluation of mammalian cell culture techniques.we have studied the effects of ultraviolet light on cells, and the phototoxic actions of a range of uv- or visible light-absorbing compounds in three separate in vitro tests (photolysis of red blood cells and phototoxicity to macrophages and to chinese hamster chv79 cells). exposure to uv light for short periods was non-toxic to primary macrophages and red blood cells, but produced extensive killing of chv79 cells. chv79 cells can repair a considerable amount of uv-induced damage by unscheduled ...20133781431
cytotoxicity, dna fragmentation and sister-chromatid exchange in chinese hamster ovary cells exposed to the lipid peroxidation product 4-hydroxynonenal and homologous aldehydes.the cytotoxic and genotoxic activities of 4-hydroxypentenal (hpe), 4-hydroxyhexenal (hhe), 4-hydroxyoctenal (hoe), 4-hydroxynonenal (hne) and 4-hydroxyundecenal (hue) were investigated in chinese hamster ovary (cho) cells. all five 4-hydroxyalkenals reduced plating efficiency in a concentration (ranging from 7 to 170 microm) lower than that producing a parallel reduction of trypan blue-excluding cells, but with both methods the increase in molarity needed to obtain a lethal effect was constantly ...20133755798
evaluation of the interaction of three genotoxic agents in eliciting sister-chromatid exchanges using response surface methodology.chinese hamster cells (v79) were treated with ethylnitrosourea (enu), bischloroethylnitrosourea (bcnu), and cis-diamminedichloroplatinum(ii) (ddp) alone and in combination. sister chromatid exchanges (sces) were quantitated as measures of genotoxicity of the three agents. the combination experiment employed a factorial design in which cells were treated, in various concentration combinations, with all agents simultaneously. response surface methodology using a polynomial model in treatment varia ...20133692012
recovery from sublethal and potentially lethal damage in an x-ray-sensitive cho cell.it has been suggested that dna strand breaks are the molecular lesions responsible for radiation-induced lethality and that their repair is the basis for the recovery of irradiated cells from sublethal and potentially lethal damage. em9 is a chinese hamster ovary cell line that is hypersensitive to killing by x rays and has been reported to have a defect in the rate of rejoining of dna single-strand breaks. to establish the importance of dna strand-break repair in cellular recovery from subletha ...20133602355
g1- and s-phase syntheses of histones h1 and h1o in mitotically selected cho cells: utilization of high-performance liquid chromatography.we have employed high-performance liquid chromatography (hplc) to investigate the syntheses of histones h1 and h1o as synchronized cells traverse from mitosis to s phase. chinese hamster (line cho) cells were synchronized by mitotic selection, and, at appropriate times, they were pulse labeled for 1 h with [3h]lysine. histones h1 and h1o were extracted by blending radiolabeled and carrier cells directly in 0.83 m hc1o4; the total hc1o4-soluble, cl3cco2h-precipitable proteins were then separated ...20133925990
adaptive cellular response to hyperthermia: 31p-nmr studies.dynamic intracellular atp and pi levels were measured non-invasively for chinese hamster v79 cells by 31p-nmr under conditions of thermotolerance and heat-shock protein induction. high densities of cells were embedded in agarose strands, placed within a standard nmr sample tube, and perfused with medium maintained either at 37 or 43 degrees c at ph 7.35. cell survival and heat-shock protein synthesis were assessed either from parallel monolayer cultures or cells dislodged from the agarose strand ...20133995087
atp-dependent degradation of 3-hydroxy-3-methylglutaryl coenzyme a reductase in permeabilized cells.a system for the assay of 3-hydroxy-3-methyglutaryl (hmg) coenzyme a (coa) reductase in digitonin-permeabilized chinese hamster ovary cells is described. under these conditions, hmg-coa reductase remained intact and associated with the endoplasmic reticulum, and values for km (hmg-coa), ki (mevinolin), and active/total activity were similar to those seen in sonicated cell preparations. however, the mechanism by which this rapidly turned over (half-life approximately 2 h) enzyme is degraded was d ...20133584146
[proliferation characteristics of multinucleate cells during prolonged exposure to cytochalasin b].the growth of the chinese hamster cell cultures for 7 days after the stopping of the prolonged cell cultivation with cytochalasin b (5 micrograms/ml, 7 days), on the one hand, results in the decrease in the amount of multinucleate cells from 75 to 25%. on the other hand, it leads to the appearance of a new class of multinucleate cells with more than 7 nuclei. by the 2nd day a rapid increase in the proliferation rate is observed both in uninucleate and multinucleate cells. then, by the 7th day, t ...20133576701
radioimmunotherapy of cryptococcus neoformans spares bystander mammalian cells.previously, we showed that radioimmunotherapy (rit) for cryptococcal infections using radioactively labeled antibodies recognizing the cryptococcal capsule reduced fungal burden and prolonged survival of mice infected with cryptococcus neoformans. here, we investigate the effects of rit on bystander mammalian cells.201324020737
mechanism of action of novel lung edema therapeutic ap301 by activation of the epithelial sodium channel.ap301 [cyclo(cgqretpegaeakpwyc)], a cyclic peptide comprising the human tumor necrosis factor lectin-like domain (tip domain) sequence, is currently being developed as a treatment for lung edema and has been shown to reduce extravascular lung water and improve lung function in mouse, rat, and pig models. the current paradigm for liquid homeostasis in the adult mammalian lung is that passive apical uptake of sodium via the amiloride-sensitive epithelial na⁺ channel (enac) and nonselective cyclic- ...201324077967
characterization of host-cell line specific glycosylation profiles of early transmitted/founder hiv-1 gp120 envelope proteins.glycosylation plays an essential role in regulating protein function by modulating biological, structural, and therapeutic properties. however, due to its inherent heterogeneity and diversity, the comprehensive analysis of protein glycosylation remains a challenge. as part of our continuing effort in the analysis of glycosylation profiles of recombinant hiv-1 envelope-based immunogens, we evaluated and compared the host-cell specific glycosylation pattern of recombinant hiv-1 surface glycoprotei ...201323339644
detection of the lethal effects of t-2 mycotoxin on cells using a rapid colorimetric viability assay.a colorimetric method of determining cell viabilities in cultured cells is described. the system is based on the ability of mitochondrial enzymes in live but not dead cells to chemically reduce a tetrazolium salt (mtt) into a colored formazan dye which can be detected at 570 nm using a multiwell scanning spectrophotometer. 48 h chinese hamster ovary (cho) cell cultures are used in the assay and the amount of colored product formed is directly proportional to cell number over a range of 0.39-12.5 ...20133686557
cell surface glycoproteins of cho cells. ii. surface distribution and pathway of internalization.the surface distribution and pathway for internalization of the major cell surface proteins of chinese hamster ovary (cho) cells have been investigated after reacting cells at 4 degrees c with the membrane-impermeant reagent trinitrobenzenesulfonate. molecules, haptenized with trinitrophenol groups, the majority of which are in a group of high molecular weight acidic glycoproteins (hmwag), were labelled at 4 degrees c with anti-dinitrophenol immunoglobulins coupled to fluorescein isothiocyanate ...20133709691
effects of thialysine on cho cells growth.thialysine, the lysine isolog with the 4-methylene group substituted by a sulfur atom, inhibits the growth rate and plating efficiency of chinese hamster ovary (cho) cells. the inhibition can be reversed by lysine, when added to the culture medium together with thialysine or shortly after; to have a complete reversion a lysine concentration five times that of thialysine is necessary. cells grown in the presence of thialysine show a decreased viability and an increased volume. thialysine inhibits ...20133934502
frequency of chromosomally unbalanced gametes in male and female hamsters heterozygous for reciprocal translocation.by using male and female chinese hamsters heterozygous for reciprocal translocation, t(2;10) 3idr and t(1;2)9idr, features of metaphase ii cells were observed, and the difference in frequency of each class of cells derived from quadrivalents was investigated. the result showed no difference between sexes in the segregation ratio of chromosomes from the quadrivalents in either strain. in four-day embryos from crosses between normal animals and translocation heterozygotes in both strains, the inci ...20133585112
mutagen-sensitive cell lines are obtained with a high frequency in v79 chinese hamster cells.a replica-plating technique has been adopted for the isolation of mutagen-sensitive mutants of chinese hamster v79 and cho cell lines. after the mutagenic treatment (enu) clones derived from these cell lines were replica plated into micro wells and replicas were treated with uv (254 nm), x-ray, mmc, emc or mms. clonal cell lines which demonstrated mutagen sensitivity were retested by the determination of survival. only one uv-sensitive line was obtained in 1500 clonal lines derived from cho cell ...20133587254
lipopolysaccharide-induced m2 to m1 macrophage transformation for il-12p70 production is blocked by candida albicans mediated up-regulation of ebi3 expression.macrophages are heterogeneous cell populations that are present in all tissues. macrophages can be divided into classically activated inflammatory macrophages (m1) and alternatively activated anti-inflammatory macrophages (m2). it has been generally accepted that m1 macrophages are polarised in an inflammatory environment to produce pro-inflammatory cytokines, whilst m2 macrophages are involved in anti-inflammation and aid tissue repair in wound healing. bacterial endotoxin (lipopolysaccharide; ...201323724011
the bacillus cereus hbl and nhe tripartite enterotoxin components assemble sequentially on the surface of target cells and are not interchangeable.bacillus cereus is a spore-forming, gram-positive bacterium commonly associated with outbreaks of food poisoning. it is also known as an opportunistic pathogen causing clinical infections such as bacteremia, meningitis, pneumonia, and gas gangrene-like cutaneous infections, mostly in immunocompromised patients. b. cereus secretes a plethora of toxins of which four are associated with the symptoms of food poisoning. two of these, the non-hemolytic enterotoxin nhe and the hemolysin bl (hbl) toxin, ...201324204713
imaging living cells surface and quantifying its properties at high resolution using afm in qi™ mode.since the last 10 years, afm has become a powerful tool to study biological samples. however, the classical modes offered (imaging or tapping mode) often damage sample that are too soft or loosely immobilized. if imaging and mechanical properties are required, it requests long recording time as two different experiments must be conducted independently. in this study we compare the new qi™ mode against contact imaging mode and force volume mode, and we point out its benefit in the new challenges ...201323522742
molecular cloning and functional characterization of the diapause hormone receptor in the corn earworm helicoverpa zea.the diapause hormone (dh) in the heliothine moth has shown its activity in termination of pupal diapause, while the orthology in the silkworm is known to induce embryonic diapause. in the current study, we cloned the diapause hormone receptor from the corn earworm helicoverpa zea (hzdhr) and tested its ligand specificities in a heterologous reporter system. hzdhr was expressed in chinese hamster ovary (cho) cells, which were co-transfected with the aequorin reporter, and was used to measure the ...201324257143
role of phospholipase a₂ (pla₂) inhibitors in attenuating apoptosis of the corneal epithelial cells and mitigation of acanthamoeba keratitis.the aim of this study is to determine if the mannose-induced protein (mip-133) from acanthamoeba castellanii trophozoites induces apoptosis of corneal epithelial cells through a cytosolic phospholipase a2α (cpla2α)-mediated pathway. the efficacy of cpla2α inhibitors to provide protection against acanthamoeba keratitis was examined in vivo. chinese hamster corneal epithelial (hcorn) cells were incubated with or without mip-133. mip-133 induces significant increase in cpla2α and macrophage inflamm ...201323792108
a single-amino-acid polymorphism in chikungunya virus e2 glycoprotein influences glycosaminoglycan utilization.chikungunya virus (chikv) is a reemerging arbovirus responsible for outbreaks of infection throughout asia and africa, causing an acute illness characterized by fever, rash, and polyarthralgia. although chikv infects a broad range of host cells, little is known about how chikv binds and gains access to the target cell interior. in this study, we tested whether glycosaminoglycan (gag) binding is required for efficient chikv replication using chikv vaccine strain 181/25 and clinical isolate sl1564 ...201324371059
quantitative detection of vibrio cholera toxin by real-time and dynamic cytotoxicity monitoring.we report here the quantitative detection of vibrio cholerae toxin (ct) in isolates and stool specimens by dynamic monitoring of the full course of ct-mediated cytotoxicity in a real-time cell analysis (rtca) system. four cell lines, including y-1 mouse adrenal tumor cells, chinese hamster ovary (cho) cells, small intestine epithelial (fhs74int) cells, and mouse adrenal gland (pc12-adh) cells, were evaluated for their suitability for ct-induced cytotoxicity testing. among them, the y-1 line was ...201324048535
confocal microscopy study of pertussis toxin and toxoids on cho-cells.pertussis toxin in its detoxified form is a major component of all current acellular pertussis vaccines. here we report the membrane translocation and internalization activities of pertussis toxin and various pertussis toxoids using chinese hamster ovary cells and confocal microscopy based on indirect immunofluorescence labeling. chemically detoxified pertussis toxoids were able to translocate/internalize into cells at the concentration about 1,000 times higher than the native toxin. pertussis t ...201323291938
cytochrome p450 cyp1b1 interacts with 8-methoxypsoralen (8-mop) and influences psoralen-ultraviolet a (puva) sensitivity.there are unpredictable inter-individual differences in sensitivity to psoralen-uva (puva) photochemotherapy, used to treat skin diseases including psoriasis. psoralens are metabolised by cytochrome p450 enzymes (p450), and we hypothesised that variability in cutaneous p450 expression may influence puva sensitivity. we previously showed that p450 cyp1b1 was abundantly expressed in human skin and regulated by puva, and described marked inter-individual differences in cutaneous cyp1b1 expression.201324086543
enhanced expression of codon optimized interferon gamma in cho cells.the human interferon-gamma (ifn-γ) is a potential drug candidate for treating various diseases due to its immunomodulatory properties. the efficient production of this protein can be achieved through a popular industrial host, chinese hamster ovary (cho) cells. however, recombinant expression of foreign proteins is typically suboptimal possibly due to the usage of non-native codon patterns within the coding sequence. therefore, we demonstrated the application of a recently developed codon optimi ...201323876479
identification of a novel endogenous regulatory element in chinese hamster ovary cells by promoter trap.the objective of this study was to identify and isolate endogenous promoters in chinese hamster ovary (cho) cells using a promoter trap approach. a promoter-less vector harboring a green fluorescent protein (gfp)-hygromycin resistance gene cassette was designed and transfected into cho cells. putative promoters were identified by selecting for gfp(+) clones under hygromycin selection. genomic dna from these clones was then digested and self-ligated to give rise to a plasmid carrying the putative ...201323850860
investigation of the mutagenic potential of cold atmospheric plasma at bactericidal dosages.in the past few years, cold atmospheric plasma (cap) has evolved into a new tool in the fight against nosocomial infections and antibiotic-resistant microorganisms. the products generated by the plasma-electrons, ions, reactive species and uv light-represent a 'lethal cocktail' for different kinds of pathogen, which opens up possible applications in hygiene and medicine. nevertheless, to ensure the safe usage of cap on skin (e.g., to treat wounds or skin diseases) several pre-clinical in vitro s ...201323416235
identification of var2csa domain-specific inhibitory antibodies of the plasmodium falciparum erythrocyte membrane protein 1 using a novel flow cytometry assay.var2csa, a member of the plasmodium falciparum erythrocyte membrane protein 1 (pfemp1) family, is a leading candidate for use in vaccines to protect first-time mothers from placental malaria (pm). var2csa, which is comprised of a series of six duffy binding-like (dbl) domains, binds chondroitin sulfate a (csa) on placental syncytiotrophoblast. several recombinant dbl domains have been shown to bind csa. in order to identify and develop recombinant proteins suitable for clinical development, dbl2 ...201323345587
dose-dependent efficacy and safety toxicology of hydroxypyridinonate actinide decorporation agents in rodents: towards a safe and effective human dosing regimen.two hydroxypyridinone-containing actinide decorporation agents, 3,4,3-li(1,2-hopo) and 5-lio(me-3,2-hopo), are being developed for the treatment of internal actinide contamination by chelation therapy. dose-response efficacy profiles in mice were established for the removal of intravenously injected (238)pu and (241)am after parenteral and oral treatment with these chelators. in both cases, presumed efficacious doses promoted substantially greater actinide elimination rates than the currently ap ...201323289385
analysis of the landscape of biologically-derived pharmaceuticals in europe: dominant production systems, molecule types on the rise and approval trends.a thorough sort of the human drugs approved by the european medicines agency (ema) between its establishment in 1995 until june 2012 is presented herein with a focus on biologically-derived pharmaceuticals. over 200 (33%) of the 640 approved therapeutic drugs are derived from natural sources, produced via recombinant dna technology, or generated through virus propagation. a breakdown based on production method, type of molecule and therapeutic category is presented. current ema approvals demonst ...201323262060
comparative study of chinese hamster ovary cell versus escherichia coli-derived bone morphogenetic protein-2 using the critical-size supraalveolar peri-implant defect model.chinese hamster ovary (cho) cell-derived recombinant human bone morphogenetic protein-2 (rhbmp-2) has been introduced for spine, long bone, and craniofacial indications. escherichia coli- (e. coli) derived rhbmp-2 displays comparable efficacy to cho cell-derived rhbmp-2 in vitro and in small-animal models. the objective of this study is to evaluate the efficacy of e. coli-derived rhbmp-2 compared to the benchmark cho cell-derived rhbmp-2 using an established large-animal model.201322612368
chimeric hepatitis b virus/hepatitis c virus envelope proteins elicit broadly neutralizing antibodies and constitute a potential bivalent prophylactic vaccine.the development of a prophylactic vaccine against hepatitis c virus (hcv) has become an important medical priority, because 3-4 million new hcv infections are thought to occur each year worldwide. hepatitis b virus (hbv) is another major human pathogen, but infections with this virus can be prevented with a safe, efficient vaccine, based on the remarkable ability of the envelope protein (s) of this virus to self-assemble into highly immunogenic subviral particles. chimeric hbv-hcv envelope prote ...201323150224
mc3: a steady-state model and constraint consistency checker for biochemical networks.stoichiometric models provide a structural framework for analyzing steady-state cellular behavior. models are developed either through augmentations of existing models or more recently through automatic reconstruction tools. there is currently no standardized practice or method for validating the properties of a model before placing it in the public domain. considerable effort is often required to understand a model's inconsistencies before its reuse within new research efforts.201324261865
zebrafish encoded 3-o-sulfotransferase-2 generated heparan sulfate serves as a receptor during hsv-1 entry and spread.previously we reported the role of zebrafish (zf) encoded glucosaminyl 3-o-sulfotransferase-3 (3-ost-3) isoform in assisting herpes simplex virus type-1 (hsv-1) entry and spread by generating an entry receptor to hsv-1 envelope glycoprotein d (gd). however, the ability of zf encoded 3-ost-2 isoform to participate in hsv-1 entry has not been determined although it is predominantly expressed in zf brain, a prime target for hsv-1 to infect and establish lifelong latency. here we report the expressi ...201323416072
the amino terminus of herpes simplex virus 1 glycoprotein k is required for virion entry via the paired immunoglobulin-like type-2 receptor alpha.the herpes simplex virus 1 (hsv-1) glycoprotein k (gk)/ul20 protein complex is incorporated into virion envelopes and cellular membranes and functions during virus entry and cell-to-cell spread. to investigate the role of gk/ul20 in the context of a highly neurovirulent virus strain, the hsv-1(mckrae) genome was cloned into a bacterial artificial chromosome plasmid (mckbac) and utilized to construct the mutant virus mck(gkδ31-68), carrying a 37-amino-acid deletion within the gk amino terminus. t ...201323302878
an ultra scale-down characterization of low shear stress primary recovery stages to enhance selectivity of fusion protein recovery from its molecular variants.fusion proteins offer the prospect of new therapeutic products with multiple functions. the primary recovery is investigated of a fusion protein consisting of modified e2 protein from hepatitis c virus fused to human igg1 fc and expressed in a chinese hamster ovary (cho) cell line. fusion protein products inevitably pose increased challenge in preparation and purification. of particular concerns are: (i) the impact of shear stress on product integrity and (ii) the presence of product-related con ...201323436198
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