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Results 551 - 600 of 1224
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El-Batal A I - - 2000
The conditions for batch and continuous production of ethanol, using immobilized growing yeast cells of Kluyveromyces lactis, have been optimized. Yeast cells have been immobilized in hydrogel copolymer carriers composed of polyvinyl alcohol (PVA) with various hydrophilic monomers, using radiation copolymerization technique. Yeast cells were immobilized through adhesion and multiplication ...
Lister D L - - 1999
A biotransformation mixture which contained codeine and washed cells of Pseudomonas putida M10 gave rise to a number of transformation products that are of clinical importance which included hydrocodone, dihydrocodeine and 14beta-hydroxycodeine. Incubations with the same organism and codeinone gave rise to 14beta-hydroxycodeinone and 14beta-hydroxycodeine. Cell-free extracts and membrane fractions ...
Moore S E - - 1999
N-glycans play important roles during the folding and secretion of glycoproteins. Surprisingly, during the N-glycosylation of glycoproteins, considerable amounts of unconjugated polymannose-type oligosaccharides ('free OS') are generated. Although free oligosaccharides have no known function in mammalian cells, a sophisticated cellular machinery enables them to be cleared from the endoplasmic reticulum ...
Pitsillides A A - - 1999
OBJECTIVES: Synovial fluid (SF) of normal joints contains high hyaluronan (HA) concentrations. However, the mechanism by which these are controlled and how they are influenced by articulation and loading are not established. In this study, we have examined whether immobilization influences SF HA concentration and whether this is associated with ...
Manzel L - - 1999
Selected phosphorothioate oligodeoxynucleotides containing CpG (CpG-ODN) activate immune responses, including B-cell proliferation and cytokine production. The mechanism by which cells detect CpG-motifs is not known. There are conflicting reports in the literature concerning the ability of CpG-ODN linked to solid supports to stimulate immunity. We prepared a fluorescent, biotinylated CpG-ODN, ...
Domínguez J M - - 1999
Debaryomyces hansenii cells were entrapped in Ca-alginate beads and used for producing xylitol from wood hydrolyzates. Batch experiments showed that bioconversion was severely hindered when Ca-alginate beads were hardened with Al3+ solutions. As an alternative to Al3+ hardening, the improvements in both mechanical stability of bioparticles and fermenting ability of ...
Senthuran A - - 1999
Different nutritional and process parameters influencing lactic acid production by Lactobacillus casei, adsorbed to Poraver beads in a recycle batch reactor system, were studied in an attempt to set up a system having a long operational lifetime and permitting use of high substrate concentrations for maximal conversion to the product. ...
Liu Y - - 1999
The permeabilization of yeast cells with methanol, ethanol, and isopropyl alcohol under various conditions was studied to develop the preparation method of high activity whole cell biocatalysts. Recombinant Saccharomyces cerevisiae, which intracellularly overexpresses glyoxalase I and catalyzes the conversion of methylglyoxal to S-lactoylglutathione in the presence of glutathione, was used ...
Lyngberg O K - - 1999
A single-use Hg(II) patch biosensor has been developed consisting of 1.25-cm diameter patches of two acrylic vinyl acetate copolymer layers coated on polyester. The top layer copolymer was 47 microm thick whereas the bottom layer of copolymer plus E. coli cells was 30 microm thick. The immobilized E. coli HB101 ...
Ferguson A W. - - 1999
After laying an egg into a pod of Brassica napus, the female cabbage seed weevil, Ceutorhynchus assimilis, brushes the caudal setae of the eighth abdominal tergite (VIII UT) on the host pod as she walks along it, depositing oviposition-deterring pheromone (ODP). The VIII UT is periodically extended and withdrawn, thus ...
Chang T M - - 1999
The basic principles of artificial cells, encapsulation and immobilization form the basis for a number of bioartificial organs. Hemoperfusion based on encapsulated adsorbent has been in routine clinical uses for many years to remove toxins or drugs from the circulating blood. Blood substitutes based on crosslinked hemoglobin or encapsulated hemoglobin ...
Mateus DM - - 1999
Diffusion into and from kappa-carrageenan gel beads was studied, both in the absence and presence of bacterial cells, both with and without biochemical reaction. The solutes were indole, L-serine, and L-tryptophan. The reaction was that of indole and L-serine to give L-tryptophan. Established theory concerning diffusion of a single solute ...
Araujo ML - - 1999
Bioprocesses using filamentous fungi immobilized in inert supports present many advantages when compared to conventional free cell processes. However, assessment of the real advantages of the unconventional process demands a rigorous study of the limitations to diffusional mass transfer of the reagents, especially concerning oxygen. In this work, a comparative ...
Wang J - - 1999
A new cell immobilization method based on the replacement of KCl by KCl + chitosan as gelling agent was developed. The results showed that through addition of chitosan into gelling agent, the mechanical strength and thermal stability of the carrageenan gel were greatly improved. The new immobilization method was used ...
Amari L - - 1999
Because Mg2+ and Li+ ions have similar chemical properties, we have hypothesized that Li+/Mg2+ competition for Mg2+ binding sites is the molecular basis for the therapeutic action of lithium in manic-depressive illness. By fluorescence spectroscopy with furaptra-loaded cells, the free intracellular Mg2+ concentration within the intact neuroblastoma cells was found ...
Martins A M - - 1999
The determination of glyoxalase II (S-(2-hydroxyacyl)glutathione hydrolase, EC 3.1.2.6) activity is usually accomplished by monitoring the decrease of absorbance at 240 nm due to the hydrolysis of S-d-lactoylglutathione. However, it was not possible, using this assay, to detect any enzyme activity in situ, in Saccharomyces cerevisiae permeabilized cells. Glyoxalase II ...
de Alteriis E - - 1999
Expression of the SUC2 gene encoding invertase was studied using free and gelatin-immobilized yeast cells to try to explain the high activity of this enzyme exhibited by immobilized cells when allowed to grow in a nutrient medium. The results indicated that at least two factors are probably responsible for the ...
Brandenberger HR - - 1999
The controlled breakup of a disturbed jet is a well-known technique for monodisperse particle production and has been well-investigated for Newtonian and viscoelastic fluids. For the immobilization of cells in beads of a hydrogel it has been observed that there is a maximum cell concentration beyond which a monodisperse bead ...
Mulchandani A - - 1999
An improved whole-cell technology for detoxifying organophosphate nerve agents was recently developed based on genetically engineered Escherichia coli with organophosphorus hydrolase anchored on the surface. This article reports the immobilization of these novel biocatalysts on nonwoven polypropylene fabric and their applications in detoxifying contaminated wastewaters. The best cell loading (256 ...
Renner S - - 1999
Amifostine [WR-2721; H2N-(CH2)3-NH-(CH2)2-S-PO3H2] is used as a protecting agent in the chemotherapy of neuroblastoma. It is supposed that Amifostine will be transformed into its active form, the free thiol (WR-1065), easier by normal cells than by tumour cells. Analytical capillary isotachophoresis was used to determine the dephosphorylation of Amifostine in ...
Park JK - - 1999
A biosorbent was prepared by immobilizing and culturing Zoogloea ramigera cells in calcium alginate capsules to high density. The biosorbent (the cell and its exopolysaccharide "Zooglan") along with the [calcium] alginate is known to be responsible for cadmium removal. The dry weight of the biosorbent reached 107 g/L after 3 ...
Hellenbroich D - - 1999
A large-scale cultivation system for the mass cell production and extraction of the protozoon Tetrahymena thermophila has been developed on the basis of a low-cost complex nutrient medium. Cell growth and the production of extracellular proteases were investigated using a 15-l stirred-tank reactor and 13-l and 1500-l airlift reactors. Processes ...
Lee T H - - 1999
An efficient cell-loaded biosupport separator of the decantor type was developed and applied for a continuous perfusion culture to produce cyclosporin A (CyA), in which fungal cells were immobilized on Celite beads. In the preliminary experiments employing highly viscous polymer (carboxymethyl cellulose) solutions, the decantor showed good separation performances at ...
Fadda S - - 1999
Lactobacillus curvatus CECT 904 and Lactobacillus sake CECT 4808 were selected on the basis of their proteolytic activities against synthetic substrates. Further, the effects of whole cells, cell extracts, and a combination of both enzymatic sources on muscle sarcoplasmic proteins were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reverse-phase ...
Sha S H - - 1999
We have previously shown gentamicin to form a redox-active iron chelate. This study investigates whether other aminoglycosides can likewise stimulate the generation of reactive oxygen species (free radicals). Kanamycin, neomycin and streptomycin were compared to gentamicin in intact cells and in cell-free in vitro assays using luminescence detection with lucigenin ...
Shim H - - 1999
A fibrous-bed bioreactor containing the coculture of Pseudomonas putida and P. fluorescens immobilized in a fibrous matrix was developed to degrade benzene (B), toluene (T), ethylbenzene (E), and o-xylene (X) in synthetic waste streams. The kinetics of BTEX biodegradation by immobilized cells adapted in the fibrous-bed bioreactor and free cells ...
Garimorth K - - 1999
Carboxy-terminally deleted forms of STAT5 have been described to be generated in vivo either by proteolytic processing or by differential splicing mechanisms. By comparing two different cell extraction procedures, we can show that in the mammary gland carboxy-terminally deleted forms are produced in vitro and are not detectable in extracts ...
Hatanaka Y - - 1999
Cells of the halotolerant microalga Dunaliella parva immobilized in calcium-alginate gel showed morphological characteristics and photosynthetic activity similar to those of free cells. The photosynthetic activity in immobilized cells fell only about 20% during 2 weeks incubation at 5 degrees C in the light. The asymmetric reduction of hydroxyacetone to ...
Buhmeida A - - 1999
Twenty-one fine needle aspiration biopsies (FNAB) of the prostate, diagnostically classified as definitely malignant, were studied. The Papanicolaou or H&E stained samples were destained and then stained for DNA with the Feulgen reaction. DNA cytometry was applied after different sampling rules. The histograms varied according to the sampling rule applied. ...
Tondelli L - - 1998
c-myb antisense oligonucleotides (AS ODNs) were reversibly immobilized to a novel polymeric core shell nanosphere and their cellular uptake and inhibitory effect on HL60 leukemia cell proliferation studied. The nanosphere surface was so designed as to directly bind ODNs via ionic interactions and reversibly release them inside the cells. Compared ...
Li Jingkun - - 1998
The effects of growth conditions and chemical or physical treatments on the production of extracellular ice nucleators (ECINs) by Erwinia herbicola cells were investigated. The spontaneous release of ECINs, active at temperatures higher than -4 degrees C, into the environment depended on culture conditions, with optimal production when cells were ...
Coquet L - - 1998
Viable cells of Pseudomonas aeruginosa were entrapped in alginate gel layers and incubated in a minimal glucose (15 g/L)-yeast extract (2 g/L)-salt medium to form artificial biofilm-like structures. After cultivation for 2 days, the biomass distribution inside the polymer was highly heterogeneous. The cell number reached approximately 1011 cells/g gel ...
House M L - - 1998
Disseminated neoplasia (DN), a proliferative cell disorder of the circulatory system of bivalves, was first reported in oysters in 1969. Since that time, the disease has been determined to be transmissible through water-borne exposure, but the etiological agent has not been unequivocally identified. In order to determine if a viral ...
Cho H - - 1998
Using resting cells and extracts of Streptomyces clavuligerus NP1, we have been able to convert penicillin G (benzylpenicillin) to deacetoxycephalosporin G. Conversion was achieved by increasing by 45x the concentration of FeSO4 (1.8 mM) and doubling the concentration of alpha-ketoglutarate (1.28 mM) as compared with standard conditions used for the ...
Davydov I V - - 1998
Ubiquitin-dependent degradation of intracellular proteins underlies a multitude of biological processes, including the cell cycle, cell differentiation, and responses to stress. One ubiquitin-dependent proteolytic system is the N-end rule pathway, whose targets include proteins that bear destabilizing N-terminal residues. This pathway, which has been characterized only in somatic cells, is ...
Brand A - - 1998
The synthesis of hypotaurine and taurine was investigated in astroglia-rich primary cultures obtained from brains of neonatal Wistar rats using 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Cell extracts of astroglial cultures analyzed by 1H NMR spectroscopy show prominent signals of hypotaurine. To identify cysteine as precursor for hypotaurine ...
Ciani M - - 1998
Grape must fermentation by the combination of immobilized Candida stellata cells and Saccharomyces cerevisiae was carried out in order to enhance the analytical profiles of wine. Batch and continuous pre-treatment of must with immobilized C. stellata cells, followed by an inoculum of S. Cerevisiae, enhanced the analytical profiles of fermentates. ...
Nigam J N - - 1998
Saccharomyces cerevisiae cells were immobilized in agar gel and used in a tubular reactor for conversion of cane molasses to ethanol at 30 degrees C, pH 4.5. Reactor was used in a continuous operation to test the operational stability and ethanol productivity. After 100 days of continuous fermentation at a ...
Zhang L - - 1998
Since the discovery of their biocidal properties in the 1950s, organotin compounds have found a large spectrum of industrial applications such as wood and textile preservatives, fungicides and pesticides, and antifouling paint on ships and fishing equipment. The fate and environmental impact of butyltins have been the subjects of a ...
Brooks P J - - 1998
The autosomal recessive disorder xeroderma pigmentosum (XP) results from defects in the nucleotide excision repair (NER) pathway for DNA repair. NER normally repairs bulky DNA lesions, such as pyrimidine dimers resulting from UV radiation. XP patients have high rates of skin cancer, and some also develop progressive neurological degeneration. To ...
Gorokhovatsky AYu - - 1998
The possibility of creating new screening methods with a cell-free translation system has been demonstrated with a quantitative determination of diphtheria toxin and some antibiotics (puromycin, kanamycin and tetracycline) as examples. The approach proposed follows from the ability of various substances to inhibit protein synthesis. We used a wheat-germ cell-free ...
Srivastava Pradeep - - 1998
The production of Cephalosporin C was investigated in a lab-scale 1.4 l air-lift reactor (ALR), using various immobilization modes. Bioparticles were developed by forming biofilm of growing hyphae around an inorganic siran particle which contained spores of the organism. Silk sachet was the other immobilization matrix. The maximum specific growth ...
Moreau M F - - 1998
Polymerization of orthopedic cements makes use of a peroxide initiator which is decomposed by an accelerator to provide free radicals. Free radicals which act on the monomer molecules are also known to induce cell lesions and cell death. We used an in vitro model of cement polymerization to study the ...
Kanda T - - 1998
To attain long-term bioreaction in organic solvents with living microorganisms, we tried to protect the microorganisms from the toxicity of the solvent by immobilization. In this study, baker's yeast, which is not tolerant to organic solvents such as isooctane, was selected as a model microorganism and the immobilized living yeast ...
Dringen R - - 1998
The metabolism of [2-13C]glycine in astroglia-rich primary cultures obtained from brains of neonatal Wistar rats was investigated using 13C NMR spectroscopy. After a 24-h incubation of the cells in a medium containing glucose, glutamate, cysteine, and [2-13C]glycine, cell extracts and incubation media were analyzed for 13C-labeled compounds. Labeled creatine, serine, ...
Zhang Y - - 1998
A new cell immobilization method was developed in which cells of Arthrobacter simplex BY-2-3-51 were immobilized by entrapment with a polyvinyl alcohol-alginate complex carrier. The immobilized cells preparation contains spherical beads with high mechanical strength and delta 1-dehydrogenase activity. The activation conditions and enzymatic properties of the immobilized cells were ...
Hammann R - - 1998
A preliminary screening of numerous species of the order Actinomycetales, especially of the genera Mycobacterium, Nocardia, Rhodococcus, Pseudonocardia, and Streptomyces, showed that many of them are able to metabolize benzoate (B) and p-hydroxybenzoate (pHB) as indicated by growth and change of color of the pH-indicator of an agar medium. Subsequent ...
Nawaz M S - - 1998
The influences of concentration of acrylamide, pH, temperature, duration of storage of encapsulated cells and presence of different metals and chelators on the ability of immobilized cells of a Rhodococcus sp. to degrade acrylamide were evaluated. Immobilized cells (3 g) rapidly degraded 64 and 128 mM acrylamide in 3 and ...
Roy D - - 1998
In vitro transformation of ampicillin to cephalexin was studied using calcium alginate-immobilized and free Streptomyces sp. strain DRS-1 packed in glass columns. Tris-HCl buffer containing ampicillin was continuously circulated through the columns for four cycles, each cycle (with fresh ampicillin) being continued for 5 h. The pattern of product formation ...
Ayala A - - 1998
The Rotofor cell is a preparative isoelectric focusing (IEF) apparatus, in which IEF is performed entirely in free solution. Electrofocusing in Rotofor cell has been described as well-suited for use at any stage of a purification scheme. However, it has some important limitations in resolving complex mixtures of proteins. This ...
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