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pichia pastoris secretes recombinant proteins less efficiently than chinese hamster ovary cells but allows higher space-time yields for less complex proteins.chinese hamster ovary (cho) cells are currently the workhorse of the biopharmaceutical industry. however, yeasts such as pichia pastoris are about to enter this field. to compare their capability for recombinant protein secretion, p. pastoris strains and cho cell lines producing human serum albumin (hsa) and the 3d6 single chain fv-fc anti-hiv-1 antibody (3d6scfv-fc) were cultivated in comparable fed batch processes. in p. pastoris, the mean biomass-specific secretion rate (qp ) was 40-fold lowe ...201424390926
in vitro antiplasmodial activity of some medicinal plants of burkina faso.malaria remains a major public health problem due to the emergence and spread of plasmodium falciparum drug resistance. there is an urgent need to investigate new sources of antimalarial drugs which are more effective against plasmodium falciparum. one of the potential sources of antimalarial drugs is traditional medicinal plants. in this work, we studied the in vitro antiplasmodial activity of chloromethylenic, methanolic, and meoh/h2o (1/1) crude extracts and decoction obtained from eight medi ...201424318747
chemical composition, cytotoxicity and in vitro antitrypanosomal and antiplasmodial activity of the essential oils of four cymbopogon species from benin.cymbopogon species are largely used in folk medicine for the treatment of many diseases some of which related to parasitical diseases as fevers and headaches. as part of our research on antiparasitic essential oils from beninese plants, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils of four cymbopogon species used in traditional medicine as well as their cytotoxicity.201424269775
immunization with recombinantly expressed glycan antigens from schistosoma mansoni induces glycan-specific antibodies against the parasite.schistosomiasis caused by infection with parasitic helminths of schistosoma spp. is a major global health problem due to inadequate treatment and lack of a vaccine. the immune response to schistosomes includes glycan antigens, which could be valuable diagnostic markers and vaccine targets. however, no precedent exists for how to design vaccines targeting eukaryotic glycoconjugates. the di- and tri-saccharide motifs lacdinac (galnacβ1,4glcnac; ldn) and fucosylated lacdinac (galnacβ1,4(fucα1-3)glc ...201424727440
starvation of low-density lipoprotein-derived cholesterol induces bradyzoite conversion in toxoplasma gondii.lacking enzymes for sterol synthesis, the intracellular protozoan toxoplasma gondii scavenges cholesterol from host cells to multiply. t. gondii has a complex life cycle consisting of two asexual stages; the proliferative stage (tachyzoite), and the latent stage characterized by tissue cysts (bradyzoite). in vitro, bradyzoite development can be induced by mimicking host immune response stressors through treatment with ifn-γ, heat shock, nitric oxide, and high ph. however, the extent to which hos ...201424885547
assessment of mutagenic, genotoxic, and cytotoxic potential of water samples of harike wetland: a ramsar site in india using different ex vivo biological systems.harike is a wetland of international importance under the ramsar convention. the present study entails the investigation of mutagenic, genotoxic and cytotoxic effect of surface water samples collected from five different areas of the harike wetland by using the histidine reversion point mutation assay in salmonella typhimurium (ta98 and ta100) strain with or without s9, bioluminescence mutagenicity assay using vibrio harveyi (a16) strain, plasmid-nicking assay using pbr322 and 3(4,5-dimethyl-thi ...201424777664
role of hlya-positive vibrio cholerae non-o1/non-o139 on apoptosis and cytotoxicity in a chinese hamster ovary cell line.vibrio cholerae non-o1/non-o139 is capable of producing sporadic outbreaks of cholera-like diarrhea; however, the pathogenic mechanisms of this bacterium remain unclear. the objectives of this study were to: 1) compare the apoptosis induction and cytotoxicity between hlya-positive and hlya-negative strains of v. cholerae non-o1/non-o139; 2) clarify the molecular mechanisms by which these strains induce apoptosis; and 3) compare clinical and environmental v. cholerae non-o1/non-o139 isolates with ...201426466422
the development and validation of an lc-ms/ms method for the determination of a new anti-malarial compound (tk900d) in human whole blood and its application to pharmacokinetic studies in mice.malaria is one of the most lethal and life-threatening killer infectious diseases in the world, and account for the deaths of more than half a million people annually. despite the remarkable achievement made in preventing and eradicating malaria, it still remains a threat to the public health and a burden to the global economy due to the emergence of multiple-drug resistant malaria parasites. therefore, the need to develop new anti-malarial drugs is crucial. the chemistry department at the unive ...201424484513
cell-free protein expression based on extracts from cho cells.protein expression systems are widely used in biotechnology and medicine for the efficient and economic production of therapeutic proteins. today, cultivated chinese hamster ovary (cho) cells are the market dominating mammalian cell-line for the production of complex therapeutic proteins. despite this outstanding potential of cho cells, no high-yield cell-free system based on translationally active lysates from these cells has been reported so far. to date, cho cell extracts have only been used ...201424018795
dna-protein immunization using leishmania peroxidoxin-1 induces a strong cd4+ t cell response and partially protects mice from cutaneous leishmaniasis: role of fusion murine granulocyte-macrophage colony-stimulating factor dna adjuvant.to date, no universally effective and safe vaccine has been developed for general human use. leishmania donovani peroxidoxin-1 (ldpxn-1) is a member of the antioxidant family of proteins and is predominantly expressed in the amastigote stage of the parasite. the aim of this study was to evaluate the immunogenicity and protective efficacy of ldpxn-1 in balb/c mice in heterologous dna-protein immunization regimen in the presence of fusion murine granulocyte-macrophage colony-stimulating factor (mg ...201425500571
in vitro antitrypanosomal and antiplasmodial activities of crude extracts and essential oils of ocimum gratissimum linn from benin and influence of vegetative stage.different parts of ocimum gratissimum linn are largely used in folk medicine for the treatment of many diseases, some of which related to parasitical infections as fevers and headaches. in order to validate their use and to clarify the plant part which possesses the best antiparasitic properties, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils and crude extracts from leaves, stems and seeds of ocimum gratissimum as well as their cytotoxicity.201425058875
the macrophage galactose-type lectin can function as an attachment and entry receptor for influenza virus.specific protein receptors that mediate internalization and entry of influenza a virus (iav) have not been identified for any cell type. sialic acid (sia), the primary attachment factor for iav hemagglutinin, is expressed by numerous cell surface glycoproteins and glycolipids, confounding efforts to identify specific receptors involved in virus infection. lec1 chinese hamster ovary (cho) epithelial cells express cell surface sia and bind iav yet are largely resistant to infection. here, we demon ...201424257596
classifying squamous cell carcinoma of the head and neck: prognosis, prediction and implications for therapy.traditionally, squamous cell cancers of the head and neck (scchn) have been classified by their anatomic location and stage. this system has been unsatisfactory in that it leaves substantial heterogeneity in prognosis and inadequate definition of optimal therapy. the most promising novel marker for superior prognosis in scchn is human papillomavirus (hpv). overexpression of the egfr bears an adverse prognosis; no marker provides clear predictive power for benefit from egfr inhibition. low expres ...201424313652
egfp-phsens as a highly sensitive fluorophore for cellular ph determination by fluorescence lifetime imaging microscopy (flim).the determination of ph in the cell cytoplasm or in intracellular organelles is of high relevance in cell biology. also in plant cells, organelle-specific ph monitoring with high spatial precision is an important issue, since e.g. δph across thylakoid membranes is the driving force for atp synthesis critically regulating photoprotective mechanisms like non-photochemical quenching (npq) of chlorophyll (chl) fluorescence or the xanthophyll cycle. in animal cells, ph determination can serve to moni ...201424742974
simplifying the synthesis of siga: combination of diga and rhsc using affinity chromatography.the mucosal epithelia together with adaptive immune responses, such as local production and secretion of dimeric and polymeric immunoglobulin a (iga), are a crucial part of the first line of defense against invading pathogens. iga is primarily secreted as siga and plays multiple roles in mucosal defense. the study of siga-mediated protection is an important area of research in mucosal immunity but an easy, fast and reproducible method to generate pathogen-specific siga in vitro has not been avai ...201423811333
[antibody persistence following booster vaccination with three doses of hepatitis b vaccines among low-response adults in zhangqiu county of shandong province: 24-month of follow-up from 2009].to assess the 24-month efficacy after booster vaccination with 3 doses of hepatitis b vaccine among low-response adults in zhangqiu county of shandong province.201425619213
modulation of hepatitis b surface antigen secretion by annexin ii expressed in hepatitis b virus‑producing hepatoma cells.the role of annexin ii in hepatitis b virus (hbv)‑associated hepatocellular carcinoma (hcc) remains to be elucidated. intracellular hepatitis b surface antigen (hbsag)‑retention contributes to the induction of hepatocarcinogenesis. the present study aimed to investigate the regulation of hbsag secretion by annexin ii expressed in hbv‑producing hepatoma cells. the expression of annexin ii was analyzed using western blot analysis in smmc‑7721, hepg2, hepg2.2.15, 293t and chinese hamster ovary (cho ...201425270731
avian influenza h5 hemagglutinin binds with high avidity to sialic acid on different o-linked core structures on mucin-type fusion proteins.the interaction between p-selectin glycoprotein ligand-1/mouse igg2b (psgl-1/migg(2b)) fusion protein carrying multiple copies of the influenza hemagglutinin receptor siaα2-3gal on different o-glycan chains and recombinant human influenza h5n1 a/vietnam/1203/04 hemagglutinin was investigated with a biacore biosensor. the fusion protein was produced by stable cell lines in large scale cultures and purified with affinity- and gel filtration chromatography. thec-p55 and 293-p cell lines were establ ...201424233973
the cholesterol-binding motif of the hiv-1 glycoprotein gp41 regulates lateral sorting and oligomerization.enveloped viruses often use membrane lipid rafts to assemble and bud, augment infection and spread efficiently. however, the molecular bases and functional consequences of the partitioning of viral glycoproteins into microdomains remain intriguing questions in virus biology. here, we measured foerster resonance energy transfer by fluorescence lifetime imaging microscopy (flim-fret) to study the role of distinct membrane proximal regions of the human immunodeficiency virus glycoprotein gp41 for l ...201424844300
a high-yielding cho transient system: coexpression of genes encoding ebna-1 and gs enhances transient protein expression.an efficient rapid protein expression system is crucial to support early drug development. transient gene expression is an effective route, and to facilitate the use of the same host cells as for subsequent stable cell line development, we have created a high-yielding chinese hamster ovary (cho) transient expression system. suspension-adapted cho-k1 host cells were engineered to express the gene encoding epstein-barr virus (ebv) nuclear antigen-1 (ebna-1) with and without the coexpression of the ...201424106171
development of lentiviral vectors for transient and stable protein overexpression in mammalian cells. a new strategy for recombinant human fviii (rhfviii) production.recombinant protein overexpression in mammalian cells constitutes a real challenge in therapeutic protein production. following the discovery of intron functionality in gene expression, various expression vectors that include them in their sequences have been developed. in this study, the main goal was to develop new lentiviral vectors (lvs) carrying different promoter and intron-containing 5'utr (5' untranslated region) combinations and the design of lvs for rhfviii production in chinese hamste ...201424275638
synthetic promoters for cho cell engineering.we describe for the first time the creation of a library of 140 synthetic promoters specifically designed to regulate the expression of recombinant genes in cho cells. initially, 10 common viral promoter sequences known to be active in cho cells were analyzed using bioinformatic sequence analysis programs to determine the identity and relative abundance of transcription factor regulatory elements (tfres; or transcription factor binding sites) they contained. based on this, 28 synthetic reporters ...201424615264
differential glycosylation of envelope gp120 is associated with differential recognition of hiv-1 by virus-specific antibodies and cell infection.hiv-1 entry into host cells is mediated by interactions between the virus envelope glycoprotein (gp120/gp41) and host-cell receptors. n-glycans represent approximately 50% of the molecular mass of gp120 and serve as potential antigenic determinants and/or as a shield against immune recognition. we previously reported that n-glycosylation of recombinant gp120 varied, depending on the producer cells, and the glycosylation variability affected gp120 recognition by serum antibodies from persons infe ...201425120578
zebrafish 3-o-sulfotransferase-4 generated heparan sulfate mediates hsv-1 entry and spread.rare modification of heparan sulfate (hs) by glucosaminyl 3-o sulfotransferase (3-ost) isoforms generates an entry receptor for herpes simplex virus type-1 (hsv-1). in the zebrafish (zf) model multiple 3-ost isoforms are differentially expressed. one such isoform is 3-ost-4 which is widely expressed in the central nervous system of zf. in this report we characterize the role of zf encoded 3-ost-4 isoform for hsv-1 entry. expression of zf 3-ost-4 into resistant chinese hamster ovary (cho-k1) cell ...201424498308
identification of antibody glycosylation structures that predict monoclonal antibody fc-effector function.to determine monoclonal antibody (mab) features that predict fragment crystalizable (fc)-mediated effector functions against hiv.201425160934
improved elongation factor-1 alpha-based vectors for stable high-level expression of heterologous proteins in chinese hamster ovary cells.establishing highly productive clonal cell lines with constant productivity over 2-3 months of continuous culture remains a tedious task requiring the screening of tens of thousands of clonal colonies. in addition, long-term cultivation of many candidate lines derived in the absence of drug selection pressure is necessary. expression vectors based on the elongation factor-1 alpha (eef1a) gene and the dihydrofolate reductase (dhfr) selection marker (with separate promoters) can be used to obtain ...201424929670
editorial: latest methods and advances in biotechnology.the latest "biotech methods and advances" special issue of biotechnology journal continues the btj tradition of featuring the latest breakthroughs in biotechnology. the special issue is edited by our editors-in-chief, prof. sang yup lee and prof. alois jungbauer and covers a wide array of topics in biotechnology, including the perennial favorite workhorses of the biotech industry, chinese hamster ovary (cho) cell and escherichia coli.201424408606
quantitation of the residual dna from rice-derived recombinant human serum albumin.residual dna in recombinant protein pharmaceuticals can potentially cause safety issues in clinical applications; thus, maximum residual limit has been established by drug safety authorities. assays for residual dna in escherichia coli, yeast, and chinese hamster ovary (cho) cell expression systems have been established, but no rice residual dna assay for rice expression systems has been designed. to develop an assay for the quantification of residual dna that is produced from rice seed, we esta ...201424388867
effects of two amino acid substitutions in the capsid proteins on the interaction of two cell-adapted panasia-1 strains of foot-and-mouth disease virus serotype o with heparan sulfate receptor.some cell-adapted strains of foot-and-mouth disease virus (fmdv) can utilize heparan sulfate (hs) as a receptor to facilitate viral infection in cultured cells. a number of independent sites on the capsid that might be involved in fmdv-hs interaction have been studied. however, the previously reported residues do not adequately explain hs-dependent infection of two cell-adapted panasia-1 strains (o/tibet/cha/6/99tc and o/fujian/cha/9/99tc) of fmdv serotype o. to identify the molecular determinan ...201425056022
the safety of β-carotene from yarrowia lipolytica.crystalline β-carotene from genetically modified yarrowia lipolytica is an alternative source of β-carotene for use as a nutritional supplement. to support the use of β-carotene from y. lipolytica as a food ingredient, the genotoxic and subchronic toxicity potential of this compound was determined. genotoxicity was examined using salmonella typhimurium and escherichia coli (ames test), a chromosomal aberration assay in chinese hamster ovary wbl cells, and the micronucleus test in cd-1 mice. all ...201424355170
complement protective epitopes and cd55-microtubule complexes facilitate the invasion and intracellular persistence of uropathogenic escherichia coli.escherichia coli-bearing dr-adhesins (dr+ e. coli) cause chronic pyelonephritis in pregnant women and animal models. this chronic renal infection correlates with the capacity of bacteria to invade epithelial cells expressing cd55. the mechanism of infection remains unknown.201424259524
in vitro genotoxicity assessment of a novel resveratrol analogue, hs-1793.resveratrol has received considerable attention as a polyphenol with various biological effects such as anti-inflammatory, anti-oxidant, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. as part of the overall safety assessment of hs-1793, a novel resveratrol analogue free from the restriction of metabolic instability and the high dose requirement of resveratrol, we assessed genotoxicity in three in vitro assays: a bacterial mutation assay, a comet assay, and a chromosomal aber ...201425343016
evaluation of cells and biological reagents for adventitious agents using degenerate primer pcr and massively parallel sequencing.we employed a massively parallel sequencing (mps)-based approach to test reagents and model cell substrates including chinese hamster ovary (cho), madin-darby canine kidney (mdck), african green monkey kidney (vero), and high five insect cell lines for adventitious agents. rna and dna were extracted either directly from the samples or from viral capsid-enriched preparations, and then subjected to mps-based non-specific virus detection with degenerate oligonucleotide primer (dop) pcr. mps by 454, ...201425454874
up-regulation of cluster of differentiation (cd) 11b expression on the surface of canine granulocytes with human granulocyte-macrophage colony-stimulating factor (gm-csf).granulocyte-macrophage colony-stimulating factor (gm-csf) is a pleiotropic cytokine, sharing a common beta subunit (cdw131) with interleukins 3 and 5. gm-csf is important for its direct and indirect involvement in host defense. in veterinary medicine, human (h) gm-csf has been used as a substitute for canine gm-csf to stimulate canine granulocytes and macrophages. in this study, we compared the effects of three distinct hgm-csfs produced by bacteria, yeasts and chinese hamster ovary (cho) cells ...201424829080
shiga toxin-induced apoptosis is more efficiently inhibited by dimeric recombinant hybrid-igg/iga immunoglobulins than by the parental igg monoclonal antibodies.shiga toxin 1 (stx1) is a virulence factor of enterohaemorrhagic escherichia coli strains such as o157:h7 and shigella dysenteriae. to prevent entry of stx1 from the mucosal surface, an immunoglobulin a (iga) specific for stx1 would be useful. due to the difficulty of producing iga monoclonal antibodies (mab) against the binding subunit of stx1 (stx1b) in mice, we took advantage of recombinant technology that combines the heavy chain variable region from stx1b-specific igg1 mab and the fc region ...201425469594
fabrication of swcnt-ag nanoparticle hybrid included self-assemblies for antibacterial applications.the present article reports the development of soft nanohybrids comprising of single walled carbon nanotube (swcnt) included silver nanoparticles (agnps) having superior antibacterial property. in this regard aqueous dispersing agent of carbon nanotube (cnt) containing a silver ion reducing unit was synthesised by the inclusion of tryptophan and tyrosine within the backbone of the amphiphile. the dispersions were characterized spectroscopically and microscopically using tem, afm and raman spectr ...201425191756
direct real-time quantitative pcr for measurement of host-cell residual dna in therapeutic proteins.real-time quantitative pcr (qpcr) is important for quantification of residual host cell dna (resdna) in therapeutic protein preparations. typical qpcr protocols involve dna extraction steps complicating sample handling. here, we describe a "direct qpcr" approach without dna extraction. to avoid interferences of dna polymerase with a therapeutic protein, proteins in the samples were digested with proteinase k (pk) in the presence of sodium dodecyl sulfate (sds). tween 20 and nacl were included to ...201425151232
safety assessment of epa-rich polar lipid oil produced from the microalgae nannochloropsis oculata.almega pl is an eicosapentaenoic acid-rich ω-3 oil that is isolated from nannochloropsis oculata algae and developed as a dietary supplement. the safety of the algal oil was evaluated in 14- and 90-day studies in sprague-dawley rats by oral gavage at dose levels of 0, 250, 500, and 2500 mg/kg/d and 0, 200, 400, and 2000 mg/kg/d, respectively. no mortalities occurred and no signs of toxicity were observed during the studies. no treatment-related effects were seen for body weight, food consumption ...201425305242
high expression of fusion proteins consisting of a single-chain variable fragment antibody against a tumor-associated antigen and interleukin-2 in escherichia coli.the aim of this study was to establish a strategy for high-level production of single-chain variable fragment (scfv) antibodies fused with interleukin-2 (il-2) in escherichia coli.201425075015
genotoxicity evaluation of guibi-tang extract using an in vitro bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus test.guibi-tang is a traditional herbal prescription made from 12 different herbs that is used in the treatment of amnesia and poor memory.201424985139
low concentrations of recombinant granulocyte macrophage-colony stimulating factor derived from chinese hamster ovary cells augments long-term bioactivity with delayed clearance in vitro.to date, the biological activity of granulocyte macrophage-colony stimulating factor (gm-csf) has been investigated by using mostly escherichia coli- or yeast cell-derived recombinant human gm-csf (erhgm-csf and yrhgm-csf, respectively). however, chinese hamster ovary cell-derived recombinant human gm-csf (crhgm-csf), as well as natural human gm-csf, is a distinct molecule that includes modifications by complicated oligosaccharide moieties. in the present study, we reevaluated the bioactivity of ...201424813650
establishment of a signal peptide with cross-species compatibility for functional antibody expression in both escherichia coli and chinese hamster ovary cells.signal peptides are short peptides located at the n-terminus of secreted proteins. they characteristically have three domains; a basic region at the n-terminus (n-region), a central hydrophobic core (h-region) and a carboxy-terminal cleavage region (c-region). although hundreds of different signal peptides have been identified, it has not been completely understood how their features enable signal peptides to influence protein expression. antibody-derived signal peptides are often used to prepar ...201424755069
enhancement of dna vaccine efficacy by intracellular targeting strategies.immune response against an encoded antigenic protein can be elicited by including targeting sequences to dna vaccines that promote protein sorting to processing pathways, related with antigen presentation by major histocompatibility complexes (mhc). candidate dna vaccines coding for neuraminidase 3 of the avian influenza virus were designed to encode different sequences that direct the protein to specific cellular compartments such as endoplasmic reticulum (i.e., adenovirus e1a), lysosomes (i.e. ...201424715281
affinity chromatography of proteins on monolithic columns.at present, monolithic stationary phases, because of their morphology, are widely used for development and realization of fast dynamic and static processes based on mass transition between liquid and solid phases. these are liquid chromatography, solid phase synthesis, microarrays, flow-through enzyme reactors, etc. high-performance liquid chromatography on monoliths, including bioaffinity mode, represents a unique technique appropriate for fast and efficient separation of biological (macro)mole ...201424648084
purification and characterization of a novel lipopeptide from streptomyces amritsarensis sp. nov. active against methicillin-resistant staphylococcus aureus.nowadays antimicrobial lipopeptides are being widely exploited for developing potential therapeutic agents for treating bacterial infections. in the present study, we have purified and characterized an antimicrobial lipopeptide produced by streptomyces amritsarensis sp. nov. (= mtcc 11845(t) = jcm 19660(t)). the lipopeptide was purified using silica gel chromatography, size exclusion chromatography and reverse phase- hplc. the ms/ms analysis of the lipopeptide revealed that it has amino acid seq ...201425006539
the ucsc genome browser database: 2015 update.launched in 2001 to showcase the draft human genome assembly, the ucsc genome browser database (http://genome.ucsc.edu) and associated tools continue to grow, providing a comprehensive resource of genome assemblies and annotations to scientists and students worldwide. highlights of the past year include the release of a browser for the first new human genome reference assembly in 4 years in december 2013 (grch38, ucsc hg38), a watershed comparative genomics annotation (100-species multiple align ...201425428374
escherichia coli as a glycoprotein production host: recent developments and challenges.chinese hamster ovary cells are the most popular host expression system for the large-scale production of human therapeutic glycoproteins, but, the race to engineer escherichia coli to perform glycosylation is gathering pace. the successful functional transfer of an n-glycosylation pathway from campylobacter jejuni to escherichia coli in 2002 can be considered as the crucial first engineering step. here, we discuss the recent advancements in the field of n-glycosylation of recombinant therapeuti ...201425156401
use of slam and pvrl4 and identification of pro-hb-egf as cell entry receptors for wild type phocine distemper virus.signalling lymphocyte activation molecule (slam) has been identified as an immune cell receptor for the morbilliviruses, measles (mv), canine distemper (cdv), rinderpest and peste des petits ruminants (pprv) viruses, while cd46 is a receptor for vaccine strains of mv. more recently poliovirus like receptor 4 (pvrl4), also known as nectin 4, has been identified as a receptor for mv, cdv and pprv on the basolateral surface of polarised epithelial cells. pvrl4 is also up-regulated by mv in human br ...201425171206
sequencing, annotation and analysis of the syrian hamster (mesocricetus auratus) transcriptome.the syrian hamster (golden hamster, mesocricetus auratus) is gaining importance as a new experimental animal model for multiple pathogens, including emerging zoonotic diseases such as ebola. nevertheless there are currently no publicly available transcriptome reference sequences or genome for this species.201425398096
wound healing potential of antibacterial microneedles loaded with green tea extracts.this study evaluates the utility of an antibacterial microneedle composed of green tea (gt) extract and hyaluronic acid (ha), for the efficient delivery of gt. these microneedles have the potential to be a patient-friendly method for the conventional sustained release of drugs. in this study, a fabrication method using a mold-based technique to produce gt/ha microneedles with a maximum area of ~50mm(2) with antibacterial properties was used to manufacture transdermal drug delivery systems. fouri ...201425063177
quantification of potassium levels in cells treated with bordetella adenylate cyclase toxin.the aim of this study was to compare two methods for quantification of changes in intracellular potassium concentration (decrease from ∼140 to ∼20mm) due to the action of a pore-forming toxin, the adenylate cyclase toxin (cyaa) from the pathogenic bacterium bordetella pertussis. cyaa was incubated with stably transfected k1 chinese hamster ovary cells expressing the toxin receptor cd11b/cd18 and the decrease in potassium concentration in the cells was followed by inductively coupled plasma mass ...201424412166
lipoteichoic acid of streptococcus mutans interacts with toll-like receptor 2 through the lipid moiety for induction of inflammatory mediators in murine macrophages.streptococcus mutans is a pathogenic gram-positive bacterium that is closely associated with dental caries and subsequent pulpal inflammation. although lipoteichoic acid (lta) is considered a major virulence factor of gram-positive bacteria, little is known about the innate immunity to s. mutans lta. in this study, we purified lta from s. mutans (sm.lta) through n-butanol extraction, hydrophobic interaction column chromatography, and ion-exchange column chromatography to investigate its immunolo ...201424216318
reciprocal effects of phenothiazines and naphthalene sulfonamides on the external atp-dependent permeability change in chinese hamster ovary cells.external atp causes a great increase in passive permeability to phosphorylated metabolites in several transformed cells, but not in untransformed cells. we have previously demonstrated that the external atp-dependent permeability change was induced in chinese hamster ovary cells, cho-k1, only in the presence of a mitochondrial inhibitor (rotenone, kcn) or a cytoskeleton-attacking agent, vinblastine (kitagawa, t. and akamatsu, y. biochim. biophys. acta 649, 76-82 (1981); 734, 25-32 (1983]. a simi ...20143986199
filter-aided n-glycan separation (fangs): a convenient sample preparation method for mass spectrometric n-glycan profiling.we have developed a simple method for the release and isolation of glycoprotein n-glycans from whole-cell lysates using less than a million cells, for subsequent implementation with mass spectrometric analysis. cellular protein extracts prepared using sds solubilization were sequentially treated in a membrane filter device to ultimately release glycans enzymatically using pngase f in the volatile buffer ammonium bicarbonate. the released glycans are recovered in the filtrate following centrifuga ...201424450425
systematic transfer of prokaryotic sensors and circuits to mammalian cells.prokaryotic regulatory proteins respond to diverse signals and represent a rich resource for building synthetic sensors and circuits. the tetr family contains >10(5) members that use a simple mechanism to respond to stimuli and bind distinct dna operators. we present a platform that enables the transfer of these regulators to mammalian cells, which is demonstrated using human embryonic kidney (hek293) and chinese hamster ovary (cho) cells. the repressors are modified to include nuclear localizat ...201425360681
coxiella burnetii type iv secretion-dependent recruitment of macrophage autophagosomes.coxiella burnetii is an intracellular gram-negative bacterium that causes human q fever, a flu-like disease that can progress to chronic, life-threatening endocarditis. in humans, c. burnetii infects alveolar macrophages and promotes phagosomal fusion with autophagosomes and lysosomes, establishing a unique parasitophorous vacuole (pv) in which to replicate. the pathogen uses a dot/icm type iv secretion system (t4ss) to deliver effector proteins to the host cytoplasm, where they alter cellular p ...201424643534
residue 82 of the chikungunya virus e2 attachment protein modulates viral dissemination and arthritis in mice.chikungunya virus (chikv) is a mosquito-borne alphavirus that has reemerged to cause profound epidemics of fever, rash, and arthralgia throughout sub-saharan africa, southeast asia, and the caribbean. like other arthritogenic alphaviruses, mechanisms of chikv pathogenesis are not well defined. using the attenuated chikv strain 181/25 and virulent strain af15561, we identified a residue in the e2 viral attachment protein that is a critical determinant of viral replication in cultured cells and pa ...201425142598
different efficiencies of interaction between 3-aminobenzamide and various monofunctional alkylating agents in the induction of sister chromatid exchanges.3-aminobenzamide (3ab), an inhibitor of poly(adp-ribose) polymerase, interacts synergistically with certain monofunctional alkylating agents to increase the frequency of sister chromatid exchanges (sces) in chinese hamster ovary cells (cho). not all alkylating agents interact with 3ab to the same extent. because 3ab has been reported to inhibit dna strand break rejoining, experiments were carried out to determine if 3ab interacts preferentially with alkylation-induced dna strand breaks or some o ...20144006055
arrest of chinese hamster cells in g 2 following treatment with the anti-tumor drug bleomycin. 20144112708
the effect of cell-to-cell contact on the surface morphology of chinese hamster ovary cells.in the previous report (porter et al., in this issue) morphological changes in chinese hamster ovary (cho) cells during the cell cycle were described. in this report we describe the role of intercellular contact on these changes. we find that intercellular contact is required for cells to exhibit the morphologies porter et al. described for s and g(2). when cells are synchronized by mitotic selection and plated onto cover slips at very low density such that no intercellular contact occurs, the c ...20144735454
[proceedings: comparative studies of chromosome stripe pattern in giemsa and fluorescent staining of gonosomal and somatic cells in chinese hamsters]. 20144142250
hyperthermia-induced cell death, thermotolerance, and heat shock proteins in normal, respiration-deficient, and glycolysis-deficient chinese hamster cells.hyperthermia-induced cell inactivation, thermotolerance development, and heat shock protein synthesis were characterized in a chinese hamster cell line and its two derivatives, respectively, deficient in glycolysis and respiration. no difference was found in the intrinsic thermosensitivity of the cells or in their ability to respond to heat by developing thermotolerance and synthesizing the heat shock proteins. the results indicate that the direct thermal inactivation of either respiration or gl ...20143940198
effect of hypoxia on recovery from damage induced by heat and radiation in plateau-phase cho cells.the effect of hypoxia on the induction of and recovery from damage by radiation alone and in combination with heat has been investigated using plateau-phase chinese hamster ovary (cho) cells. postirradiation hypoxia reduced the potentially lethal damage recovery (pldr) in cells irradiated under an euoxic state and completely eliminated pldr in cells irradiated under hypoxia. cells which were maintained under hypoxia during both irradiation and a 4-hr recovery period and then incubated for a furt ...20143975360
[comparison of chain breaks produced in dna in vivo by gamma rays and neutrons; hypothesis of a new dna radiolesion].using the method of alkaline elution for the treatment of cell dna in chinese hamster fibroblasts irradiated with low doses of either cobalt-60 gamma rays or p (34 mev) be neutrons, we determined the kinetics of radio-induced strand breaks. the comparison gamma rays-neutrons reveals important discrepancies which suggest that neutrons induce a so for unknown reaction in dna simultaneously with single and double strand breakage. this observation could contribute to explain the high rbe value of hi ...20143930008
in vitro cytotoxicity of glycol ethers and oxidation products in cho cells.the cytotoxicity of several glycol ethers and of some of their oxidation products, the corresponding alkoxy acetates, was compared in chinese hamster ovary (cho-k1) cells without metabolic activation. cytotoxicity was measured in terms of cloning formation ability, and ec50 values (concentrations allowing 50% of the seeded cells to form colonies) were estimated. the results, in the case of unmetabolized glycol ethers tested, showed an increase in toxicity with increasing chain length. the cytoto ...20144024159
[influence on serum insulin concentration of sodium glymidine (glykodiazine), isopropylnorepinephrine, glucagon and theophylline in chinese hamsters with spontaneous or streptozotocin-induced diabetes mellitus]. 20144269691
quantitative tritium autoradiography of mammalian chromosomes. ii. the kinetics of dna synthesis in individual chromosomes of chinese hamster fibroblasts. 20144249899
minor xp21 chromosome deletion in a male associated with expression of duchenne muscular dystrophy, chronic granulomatous disease, retinitis pigmentosa, and mcleod syndrome.we are reporting a male patient who suffered from chronic granulomatous disease associated with cytochrome b-245 deficiency and mcleod red cell phenotype, duchenne muscular dystrophy, and retinitis pigmentosa. on cytogenetic analysis, he seemed to have a very subtle interstitial deletion of part of band xp21. since it was impossible to know whether this material was truly deleted or inserted elsewhere in the genome, somatic cell and molecular studies were carried out. in somatic cell hybrids, th ...20144039107
5-amino-4-imidazolecarboxamide riboside (z-riboside) metabolism in eukaryotic cells.metabolites of 5-amino-4-imidazolecarboxamide riboside (z-riboside) have potential roles in the regulation of cellular metabolism and as pharmacological agents in several pathological situations. before studying z-riboside metabolism it was necessary to develop methods for identifying and quantitating 5(4)-amino-4(5)-imidazolecarboxamide metabolites. these studies utilized chinese hamster ovary fibroblast auxotrophic mutants to identify and isolate compounds relevant to z-riboside metabolism by ...20143997815
temperature effect on mitoxantrone cytotoxicity in chinese hamster cells in vitro.the effect of heat on 1,4-dihydroxy-5,8-bis[2-[(2-hydroxyethyl)amino]ethylamino]-9, 10-anthracenedione dihydrochloride (dhad; mitoxantrone, nsc 301739) cytotoxicity was studied in v79 chinese hamster cells. an overnight exposure to the drug at 40 degrees c enhanced drug damage in chromosome aberrations, culture growth, and cellular reproductive integrity. preincubation of cells overnight in medium containing no drug at this temperature also showed some enhancement in subsequent dhad lethality (a ...20144016740
[karyotypic characteristics of the chinese hamster cell line cho-k1 resistant to colchicine].karyological analysis was made of g-banded chromosomes in the cells of three independent cho-k1 clones stably resistant to colchicine (clch) selected for resistance to clch at the concentration 0.1 mkg/ml (the first step of selection), and of one clone with higher but unstable level of resistance (2 mkg/ml--the second level of resistance). the results obtained revealed a morphological instability of the p-shoulder of chromosome z6: more often an additional genetical material (agm) at the distal ...20143952816
sce induction is uncoupled from mutation induction in mammalian cells following exposure to ethylnitrosourea (enu).it has been suggested not only that sister chromatid exchange (sce) induction might serve as a qualitative indicator of mutagenesis, but also that induced sce frequencies are linearly related to induced mutation frequencies. the consistency of the relationship between sces and mutations was tested in the present work. confluent chinese hamster ovary (cho) cells were exposed to ethylnitrosourea (enu) and then held at confluency for various times prior to initiation of sce and mutation assays. cel ...20143971960
the carcinogenic effect of dibutylnitrosamine in syrian and chinese hamsters. 20144254292
[effect of ionizing radiation on the membrane potential and electrical input resistance of chinese hamster fibroblast membranes].x-irradiation with a dose of 8 gy leads to a sharp decrease in membrane potential of cultured chinese hamster cells followed by restoration thereof. changes in the membrane potential are accompanied by a monotonous increase of mean values of input cell resistance. it is assumed that radiation elicits a decrease in the resistance of a plasma membrane and a concurrent increase in the resistance of intercellular gap contacts which lead to impairment of cell interaction.20144080988
[dna degradation during radiation death of cultured cells].the method of flow cytofluorometry was used to study postirradiation changes in plasma membrane permeability and dna content of the burkitt's lymphoma cells (raji line). at a dose of 10 gy, the increase in membrane permeability preceded the appearance of cells with diminished dna content. the synchronization of cells in phase g2 was associated with a virtually complete radiation arrest of mitoses. the postirradiation electrophoretic analysis of dna of the burkitt's lymphoma cells and of syrian a ...20144070564
kinetics of micronucleus expression in synchronized irradiated chinese hamster ovary cells.the kinetics of expression of radiation-induced micronuclei (mn) in synchronized chinese hamster cells (cho) was examined. the purpose of the study was to determine if the cell cycle distribution of a population significantly influences the levels of radiation induced mn, thereby obscuring the exact quantification of the radiation effect. cells were synchronized by centrifugal elutriation, irradiated, and then different phases of the cell cycle were examined for: cell cycle progression, division ...20143986869
[changes in the level of sister chromatid exchanges in cultured chinese hamster cells undergoing limited proliferation]."stationary phase ageing" of cultured chinese hamster cells (when proliferation rate decreases and in the stationary growth phase) produces an increase in the frequency of spontaneous sister chromatid exchanges (sce). thiophosphamide-induced (24 h) frequency of sce increases from 2-day to 5-day "age" and later (in the stationary phase) is practically the same. the "stationary ageing" cultured cells are suggested to be used as a model system for studying molecular-genetic age changes.20143923673
reduced culture temperature differentially affects expression and biophysical properties of monoclonal antibody variants.reduced culture temperature is an increasingly popular practice to improve recombinant protein yields in cho cells. recent studies have attributed the enhancement of protein titers at sub-physiological temperatures to increased mrna levels as well as extended stationary phase. we observed that reducing the culture temperature arrested cell growth, prolonged viability, and increased cell size. however, the reduced culture temperature had a differential effect on protein and mrna expression of clo ...201433101721
synthesis, antitubercular and anticancer activity of new baylis-hillman adduct-derived n-cinnamyl-substituted isatin derivatives.baylis-hillman adduct-derived n-cinnamyl-substituted isatin derivatives were synthesized and evaluated for their antitubercular activity on mycobacterium tuberculosis h37rv strain atcc 27294 by agar dilution method. anticancer activity for the same compounds was also screened on four different cell lines: chinese hamster ovary (cho cells), colo 205 (human colon cancer), sup-t1 (human lymphoma) and c6 glioma (rat glioma) by mtt assay method. the compounds (3j-l) have shown significant activity ag ...201432214765
a peripherally restricted p2y12 receptor antagonist altered rat tumor incidences with no human relevance: mode of action consistent with dopamine agonism.ticagrelor is an orally available, direct acting and reversible p2y12 receptor antagonist approved for treatment of acute coronary syndrome. the objectives of these studies were to (1) evaluate the ticagrelor 2-year rat carcinogenicity bioassay data; (2) investigate potential mode of action (moa) and (3) interpret human relevance.201428962330
genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food.here, we conducted in vitro genotoxicity tests to evaluate the genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food. styrene oligomers were extracted with acetone and the extract was subjected to the ames test (oecd test guideline no. 471) and the in vitro chromosomal aberration test (oecd test guideline no. 473) under good laboratory practice conditions. the concentrations of styrene dimers and trimers in the concentrated extract were 540 and 13,431 ...201428962327
evaluation of perfluorooctanoate for potential genotoxicity.perfluorooctanoate (pfoa) is a fully fluorinated eight-carbon fatty acid analog with exceptional stability toward degradation that has been used as an industrial surfactant and has been detected in environmental and biological matrices. exposures to pfoa in the workplace and in the environment have continuously stimulated investigations into its potential human health hazards. in this article, the results of fifteen unpublished genotoxicity assays conducted with perfluorooctanoate (as either the ...201428962243
conazole fungicides inhibit leydig cell testosterone secretion and androgen receptor activation in vitro.conazole fungicides are widely used in agriculture despite their suspected endocrine disrupting properties. in this study, the potential (anti-)androgenic effects of ten conazoles were assessed and mutually compared with existing data. effects of cyproconazole (cypro), fluconazole (fluc), flusilazole (flus), hexaconazole (hexa), myconazole (myc), penconazole (pen), prochloraz (pro), tebuconazole (tebu), triadimefon (tria), and triticonazole (trit) were examined using murine leydig (ma-10) cells ...201428962244
investigation of the bystander effect in cho-k1 cells.investigation of the bystander effect in chinese hamster ovary cells (cho-k1) co-cultured with cells irradiated in the dose range of 0.1-4 gy of high let 12c ions and x-rays.201428443197
comparison of the behavior of cho cells during cultivation in 24-square deep well microplates and conventional shake flask systems.in biopharmaceutical production, the optimization of cell culture media and supplementation is a vital element of process development. optimization is usually achieved through the screening of multiple media, feed and feeding strategies. however, most screening is performed in shake flasks, which makes the screening process very time consuming and inefficient. the use of small scale culture systems for the screening process can aid in the ability to screen multiple formulations during process de ...201428435799
determination of cd50s and therapeutic indices of pentostam and ureastibamine in chinese hamsters. 201412988304
experimental encephalitis virus infection in the chinese hamsters; a bacteriological and pathological study. 201414905510
[role of the processes of repair of dna damage in the repair of cytogenetic disorders. participation of the repair of dna single-strand breaks in the repair of cytogenetic disorders].a comparison was made between the results of the effect of poly(adp-ribosylation) inhibitors (e.g. nicotinamide and 3-aminobenzamide) and a chromatin proteinase inhibitor, phenylmethylsulfonylfluoride, on the cytogenetic damages repair, by a micronucleus test and dna repair in chinese hamster fibroblasts. the values of the repair half-periods (5-7 min for the cytogenetic damages and 5 min for the rapidly repaired dna damages) and a similar modifying effect with regard to radiation cytogenetic da ...20142685864
[the role of dna repair processes in the repair of cytogenetic disorders. the participation of slow to repair dna damage in the repair of cytogenetic disorders].caffeine was used to study the kinetics of cytogenetic damages repair in chinese hamster fibroblasts. its half-time (90 min) was shown to correlate with that of repair of slowly repaired dna damages. the caffeine-induced increase in the number of irreparable dna damages, attributed to inhibition of double-strand break repair, is in a quantitative correlation with the effect of the cytogenetic damage modification.20142616764
[modeling, using nucleases, of the effect of radiation on chinese hamster fibroblasts. on the role of single-stranded dna breaks, induced by dnaase i, in the initiation of chromosome aberrations].dnaase i injected to chinese hamster fibroblast cells resulted in the chromosome aberration induction at all stages of the cell cycle and death of cells. comparison of the effects of dnaase i and gamma-radiation on chinese hamster cells showed that with close values of the induced dna breaks there were close values of the cytogenetic damage and the number of dna damages per aberrant cell.20142616750
[mutations of resistance to 6-thioguanine following roentgen irradiation and subsequent treatment with cytosine arabinoside combined with hydroxyurea in chinese hamster cells in the g1 phase].a study was made of the effect of two-hour treatment of chinese hamster cells with cytosine arabinoside (arac) combined with hydroxyurea (hu) at the g1 phase of the cell cycle on lethal and mutagenic effects of x-radiation (50 to 400 cgy). the inhibitors were shown to increase a spontaneous mutation level of the resistance to 6-thioguanine: this increase augmented by 3 times as the time the treatment increased from 1-2 to 6 h. however, while sharply enhancing the inactivating effect of x-radiati ...20143057533
the influence of ionic environment on the thermal response of cultured mammalian cells.chinese hamster cells exposed to monovalent or divalent ionic solutions were sensitized to hyperthermia treatment. thermosensitization was dependent on the type of cationic salt. divalent salt solutions caused greater sensitization than monovalent salt solutions. the addition of glucose or the reduction of ph in the salt solutions did not alter thermosensitivity.20143836280
[induction of mutations resistant to 6-thioguanine by fast neutrons in cultured chinese hamster cells].a study was made of induction of mutations, resistant to 6-thioguanine (tgr), and reproductive death of chinese hamster cells after irradiation by fission-spectrum fast neutrons (mean energy of 0.75 mev) with doses of 10-130 cgy. a high relative biological effectiveness (rbe) of fast neutrons was shown. the maximum rbe values (13-16) were within the dose range inducing minimum mutagenic and lethal effects. rbe decreased with the dose increase. inspite of high mutagenic effectiveness of neutrons, ...20144070567
paradoxical glucagon response in perifused islets of the diabetic chinese hamster.dynamic insulin and glucagon response to glucose was examined in the perifusion system to investigate the relationship between pancreatic hormone content and the pattern of hormone secretion in diabetic chinese hamsters of the asahikawa colony (cha). isolated islets of normals and diabetics from the cha were perifused. when the medium was changed to high glucose (500 mg/dl), a low insulin response and paradoxical glucagon response were seen in diabetics compared with normals. positive correlatio ...20143915266
[the interphase death of dividing cells. the relation of interphase death to cell energy requirements].in experiments with irradiated cells of chinese hamster and ehrlich ascites tumor a study was made of the influence of energy provision on their interphase death rate. the presence of the uncoupler of respiration and oxidative phosphorylation--carbonyl cyanide-3-chlorophenylhydrazone--in a medium without glucose was shown to drastically increase the interphase death rate of cells of both types, whereas this effect was not observed in a medium with glucose.20142371401
[interphase death of dividing cells. relation of the death of cultured chinese hamster fibroblasts to the inter- and extracellular ph].in studying interphase death (id) of dividing cells from chinese hamster fibroblast culture a differently directed relationship between id rate and ph has been shown: the id rate increases with ph increasing from 6.6 to 8.1 and decreases with ph from 5.0 to 6.6. the dependence is the same as that observed with lymphoid cells. with radiation doses increasing from 100 to 600 gy and ph defined, the id rate increases.20142251360
[effects of a medium ph on the ability of chinese hamster cells to repair radiation injuries].in experiments with chinese hamster cells at exponential and stationary growth phases, it has been shown that the postirradiation incubation of irradiated cells in a medium with low ph (up to 6.0) promotes the recovery of cells from potentially lethal damages; it has also been found that the recovery from sublethal radiation damages does not depend on the medium ph. the long-term incubation of nonirradiated cells with low phc causes death of part of cells.20141494659
effect of caffeine on gamma-ray induced g2 arrest in well-synchronized chinese hamster ovary cells in vitro.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 ...20149132811
syngeneic fibroblasts transfected with a plasmid encoding interleukin-4 as non-viral vectors for anti-inflammatory gene therapy in collagen-induced arthritis.no effective long-term treatment is available for rheumatoid arthritis. recent advances in gene therapy and cell therapy have demonstrated efficiency in collagen-induced arthritis (cia). interleukin-4 (il-4) is already known to be efficient in cia in systemic injection or administered by gene therapy. this study was designed to evaluate the effect of a non-viral gene therapy of cia, involving injection of syngeneic fibroblasts transfected with a plasmid encoding for il-4.201412112647
study of dna damage induced by dental bleaching agents in vitro.dental bleaching is a simple and conservative procedure for aesthetic restoration of vital and non-vital discolored teeth. nevertheless, a number of studies have demonstrated the risk of tissue damage from the contact of these agents with the oral mucosa. in the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. chinese hamster ovary (cho) cells in vitro were exposed to six commercial dental bleac ...201416729174
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