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Results 401 - 450 of 1340
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Barany Sandor - - 2004
The regularities, kinetics and mechanisms of flocculation of Escherichia coli and B. thuringiensis var. israelensis (Bti) cellular suspensions by water-soluble polymers-and first of all cationic polyelectrolytes of different charge density and stiffness of the macromolecule chain have been investigated. The effect of the focculant dose and nature, its charge density, ...
Iwai Noritaka - - 2004
We have previously reported that a novel S-benzylisothiourea derivative, S-(3,4-dichlorobenzyl)isothiourea, tentatively named A22, induced spherical cells in Escherichia coli. To elucidate the structural element(s) required for inducing these spherical cells, the biological activity of S-benzylisothiourea derivatives and related compounds toward E. coli cells was investigated. S-(4-Chlorobenzyl)isothiourea revealed spherical cell-inducing activity, ...
Tanji Yasunori - - 2004
Escherichia coli has been used as an indicator of the fecal contamination of water and food, identifying potential health hazards. In this study, an E. coli-specific bacteriophage, T4, was used to detect E. coli bacteria. The T4 phage small outer capsid (SOC) protein was used to present green fluorescent protein ...
Hassan A N - - 2004
This study investigated the effect of growth in tryptic soy broth (TSB) and nutrient broth (NB) on the ability Escherichia coli O157:H7 to attach to lettuce and apple surfaces. In addition, cell surface hydrophobicity, charge and capsule production were determined on cells grown in these media. Cells grown in NB ...
Varma Archana - - 2004
The mechanisms by which bacteria adopt and maintain individual shapes remain enigmatic. Outstanding questions include why cells are a certain size, length, and width; why they are uniform or irregular; and why some branch while others do not. Previously, we showed that Escherichia coli mutants lacking multiple penicillin binding proteins ...
Ursinus Astrid - - 2004
The binding of the essential cell division protein FtsN of Escherichia coli to the murein (peptidoglycan) sacculus was studied. Soluble truncated variants of FtsN, including the complete periplasmic part of the protein as well as a variant containing only the C-terminal 77 amino acids, did bind to purified murein sacculi ...
Saint-Ruf Claude - - 2004
In Escherichia coli, the expression of the RpoS regulon is known to be crucial for survival in liquid cultures during stationary phase. By measuring cell viability and by transcriptome analysis, here we show that rpoS cells as well as wild-type cells survive when they form colonies on solid media.
Bitzan Martin - - 2004
Escherichia coli-derived verotoxins (VT; Shiga toxins) are causally related to the pathogenesis of enteropathic hemolytic uremic syndrome (HUS). Profound hemolysis is a defining feature of the disease, but it is not known whether the acute intravascular release of heme proteins contributes to HUS pathology. This study examined the biologic effects ...
Zhang Jianliang - - 2004
The insecticide resistance-associated esterase, carboxylesterase B1 (CaE B1), from mosquito was used to degrade the organophosphorus compounds. To eradicate the need for enzyme purification and minimize the resistance to mass transport of the substrate and product across the cell membranes, the CaE B1 was displayed on the cell surface of ...
Fahnert Beatrix - - 2004
Wnt-1 belongs to the Wnt family of secreted glycoproteins inducing an intracellular signaling pathway involved in cell proliferation, differentiation, and pattern formation. The canonical branch is one of three known branches. This is also valid in vitro, and Wnts can be considered beneficial for culturing primary cells from organs, provided ...
Dainiak Maria B - - 2004
The present paper describes a chromatographic capture/purification step for the recovery of proteins directly from undiluted and unclarified cell culture broths using supermacroporous dimethylacrylamide (DMAA) cryogel. The interconnected character and the size (10-100 microm) of the pores of the adsorbent make it possible to process whole cell fermentation broths without ...
Kim Jitae - - 2004
Cell lysis was demonstrated on a microfluidic CD (Compact Disc) platform. In this purely mechanical lysis method, spherical particles (beads) in a lysis chamber microfabricated in a CD, cause disruption of mammalian (CHO-K1), bacterial (Escherichia coli), and yeast (Saccharomyces cerevisiae) cells. Interactions between beads and cells are generated in the ...
Kostal Jan - - 2004
The metalloregulatory protein ArsR, which offers high affinity and selectivity toward arsenite, was overexpressed in Escherichia coli in an attempt to increase the bioaccumulation of arsenic. Overproduction of ArsR resulted in elevated levels of arsenite bioaccumulation but also a severe reduction in cell growth. Incorporation of an elastin-like polypeptide as ...
Witek Malgorzata A - - 2004
Electrokinetic transport of Escherichia coli and Saccharomyces cerevisiae (baker's yeast) cells was evaluated in microfluidic devices fabricated in pristine and UV-modified poly(methyl methacrylate)(PMMA) and polycarbonate (PC). Chip-to-chip reproducibility of the cell's apparent mobilities (micro(app)) varied slightly with a RSD of approximately 10%. The highest micro(app) for baker's yeast cells was ...
Viloria-Cols Maria E - - 2004
A common problem during recovery of bioproducts by adsorption from particulate broths is fouling of the adsorbent material as a result of the interaction of cells and cell debris, which present negative charges, with the positively charged anion exchangers commonly used in bioprocesses. The effect of shielding an adsorbent with ...
West Deborah K - - 2004
In this paper we present a new and possibly more effective way of inhibiting thymidylate synthase (TS) in cells than through the use of substrate analogue inhibitors. An inactive double mutant of TS (DM), Arg(126)Glu/Cys(146)Trp, is shown to progressively impair the reactivation of native Escherichia coli TS when the two ...
Thanedar Swapna - - 2004
Prokaryotes contain cytoskeletal proteins such as the tubulin-like FtsZ, which forms the Z ring at the cell center for cytokinesis, and the actin-like MreB, which forms a helix along the long axis of the cell and is required for shape maintenance. Using time-lapse analysis of Escherichia coli cells expressing FtsZ-GFP, ...
Yoshida N - - 2004
In the present study, Escherichia coli cells exhibited antibiotic resistance after transformation with exogenous plasmid DNA adsorbed onto chrysotile particles during agar-exposure. We previously demonstrated penetration of E. coli by chrysotile particles during agar-exposure. To further investigate the mechanism by which transformation of E. coli is achieved through the use ...
Kim Sun Young - - 2004
An SOD null mutant of Escherichia coli (IM303) and its wild-type strain (MM294) were cultivated with or without sublethal oxidative stress generated from photoexcited TiO2. Concerning maximum specific growth rate of the cells, mum, measured under various conditions, the mum value of IM303 cells increased notably in the presence of ...
Zavalova L L - - 2004
Destabilase-lysozyme (DL) from salivary gland secretion of the medicinal leech (Hirudo medicinalis) is as a member of the invertebrate lysozyme family, which sharply differs from other lysozyme families. In this study, DL lysozyme function was confirmed during expression of a gene encoding DL in Escherichia coli. Several constructs of the ...
Fajac I - - 2004
To transfer genes into airway epithelial cells, we have generated auxotrophic dap Escherichia coli BM2710 mutant that expresses the invasin of Yersinia pseudotuberculosis and the listeriolysin of Listeria monocytogenes. E. coli BM2710 harboring a plasmid carrying the gfp gene was incubated with immortalized normal or cystic fibrosis (CF) airway epithelial ...
Blume Astrid - - 2004
UDP-GlcNAc 2-epimerase/ManNAc kinase is the key enzyme of sialic acid biosynthesis in mammals. Its functional expression is a prerequisite for early embryogenesis and for the synthesis of several cell recognition motifs in adult organism. This bifunctional enzyme is involved in the development of different diseases like sialuria or hereditary inclusion ...
Vankrunkelsven Sarah - - 2004
We report on a series of preliminary experiments investigating the applicability of a novel method for the size separation of nano- and microsized particles and cells. The working principle is based on the application of a shear-driven flow through stepwise tapered micro- or nanochannels. Size separations of mixtures of 0.5 ...
Kobayashi Hideki - - 2004
Novel cellular behaviors and characteristics can be obtained by coupling engineered gene networks to the cell's natural regulatory circuitry through appropriately designed input and output interfaces. Here, we demonstrate how an engineered genetic circuit can be used to construct cells that respond to biological signals in a predetermined and programmable ...
Reid Christopher W - - 2004
The beta-hexosaminidase inhibitor and structural analog of the putative oxazolium reaction intermediate of lytic transglycosylases, N-acetylglucosamine thiazoline (NAG-thiazoline), was synthesized in 46% overall yield and tested as an inhibitor of Escherichia coli growth. NAG-thiazoline, at concentrations up to 1 mg/ml, was not found to affect the viability of E. coli ...
Albert Réka - - 2004
Evolution has provided many organisms with sophisticated sensory systems that enable them to respond to signals in their environment. The response frequently involves alteration in the pattern of movement, either by directed movement, a process called taxis, or by altering the speed or frequency of turning, which is called kinesis. ...
Ebersbach Gitte - - 2004
The par2 locus of Escherichia coli plasmid pB171 encodes oscillating ATPase ParA, DNA binding protein ParB and two cis-acting DNA regions to which ParB binds (parC1 and parC2). Three independent techniques were used to investigate the subcellular localization of plasmids carrying par2. In cells with a single plasmid focus, the ...
Moon Ki-Young - - 2004
7-Bromomethylbenz[a]anthracene is a well-known mutagen and carcinogen. The aim of this study is to determine the mutagenic potency of its two major DNA adducts [N(2)-(benz[a]anthracen-7-ylmethyl)-2'-deoxyguanosine (b[a]a(2)G) and N(6)-(benz[a]anthracen-7-ylmethyl)-2'-deoxyadenosine (b[a]a(6)A)] and the simpler benzylated analogs [N(2)-benzyl-2'-deoxyguanosine (bn(2)G) and N(6)-benzyl-2'-deoxyadenosine (bn(6)A)] in Ad293 human cells and to compare to their mutagenicity in ...
de Arruda Almeida Kleber - - 2004
The most serious problem usually encountered in the field of implanted biomedical devices is infectious morbidity as a primary source of mortality. In this work, the synthesis and characterization of a macroporous iodine-based sanitizer (iodophor), poly(caprolactone)-iodine (PCL-I(2)), are presented. Characterization methods include nuclear magnetic resonance spectroscopy, gel permeation chromatography, nitrogen ...
Figge Rainer M - - 2004
The bacterial actin homologue, MreB, is required for the maintenance of a rod-shaped cell and has been shown to form spirals that traverse along the longitudinal axis of Bacillus subtilis and Escherichia coli cells. The depletion of MreB in Caulobacter crescentus resulted in lemon-shaped cells that possessed defects in the ...
Sharma Manan - - 2004
The effects of seven commercially available alkaline cleaners used in the food processing industry, 0.025 M NaOH, and 0.025 M KOH on viability of wild-type (EDL 933) and rpoS-deficient (FRIK 816-3) strains of Escherichia coli O157:H7 in logarithmic and stationary phases of growth were determined. Cells were treated at 4 ...
Kalchayanand N - - 2004
Cell suspensions of three pathogens were exposed to hydrostatic pressure (HP), bacteriocin mixture (nisin and pediocin) or a combination of HP+bacteriocins and changes in colony forming units (cfu) and cell-morphology by scanning electron microscopy (SEM) were studied. Cell viability loss, as determined from the reduction in cfu before and after ...
Bharatan Shanti M - - 2004
A conditional lethal galE(Ts)-based strategy was employed in Escherichia coli, first to eliminate all growth-associated chromosomal reversions in lacZ or forward mutations in lacI/lacO by incubation at the restrictive temperature and subsequently to recover (as papillae) spontaneous mutations that had arisen in the population of nondividing cells after shift to ...
Li Wenhua - - 2004
The mechanism of divalent Ca2+ cation induction of Escherichia coli competence is still not fully understood, though it is a common method for introducing recombinant DNA into bacterial cells in gene engineering. Quantum dots (QDs), as a new fluorescent probe of being applied in biology research, have aroused great interest. ...
Keren Iris - - 2004
Bacterial populations produce persister cells that neither grow nor die in the presence of microbicidal antibiotics. Persisters are largely responsible for high levels of biofilm tolerance to antimicrobials, but virtually nothing was known about their biology. Tolerance of Escherichia coli to ampicillin and ofloxacin was tested at different growth stages ...
Kabir Md Shahinur - - 2004
The sigmaE regulon has been shown to perform a novel function that causes dead-cell lysis specific to the early stationary phase in addition to its well-known role in the extracytoplasmic stress response in Escherichia coli. Here, the effect of sigmaS as a general stress-responsive sigma factor on sigmaE-directed cell lysis ...
Saito Takamune T - - 2004
We previously showed that Meu13 of Schizosaccharomyces pombe functions in homologous pairing and recombination at meiosis I. Here we show that a meiosis-specific gene encodes a coiled-coil protein that complexes with Meu13 during meiosis in vivo. This gene denoted as mcp7+ (after meiotic coiled-coil protein) is an ortholog of Mnd1 ...
Tung S S Dept. of Mech. Eng., Arkansas Univ., - - 2004
We are in the process of developing a series of micro hybrid devices based on tethered flagellar motors. Examples of the devices include a microfluidic pump and a micro AC dynamo. The microfluidic pump is realized through the tethering of a harmless strain of Escherichia coli cells to a MEMS ...
Cánovas M - - 2003
The aim of this work was to understand the steps controlling the process of biotransformation of trimethylamonium compounds into L(-)-carnitine by Escherichia coli and the link between the central carbon or primary and the secondary metabolism expressed. Thus, the enzyme activities involved in the biotransformation process of crotonobetaine into L(-)-carnitine ...
Hay Michael P - - 2003
A variety of nitroheterocyclic carbamate prodrugs of phenylenediamine mustard and 5-amino-1-(chloromethyl)-3-[(5,6,7-trimethoxyindol-2-yl)carbonyl]-1,2-dihydro-3H-benz[e]indoline (amino-seco-CBI-TMI), covering a wide range of reduction potential, were prepared and evaluated for use in gene-directed enzyme prodrug therapy (GDEPT) using a two-electron nitroreductase (NTR) from Escherichia coli B. The carbamate prodrugs and corresponding amine effectors were tested in ...
Marchès Olivier - - 2003
Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. Both use a type III secretion system (TTSS) encoded by the 'locus of enterocyte effacement' (LEE) to subvert and attach to epithelial cells through the injection of a repertoire of effector molecules. Here, we report the identification ...
Veiga Esteban - - 2003
We report here that fusions of single-chain antibodies (scFvs) to the autotransporter beta domain of the IgA protease of Neisseria gonorrhoeae are instrumental in locating virus-neutralizing activity on the cell surface of Escherichia coli. E. coli cells displaying scFvs against the transmissible gastroenteritis coronavirus on their surface blocked in vivo ...
Manasherob Robert - - 2003
Compaction of the Escherichia coli nucleoid in the cell's centre was associated with the loss of colony-forming ability; these effects were caused by induction of Cyt1Aa, the cytotoxic 27 kDa protein from Bacillus thuringiensis subsp. israelensis. Cyt1Aa-affected compaction of the nucleoids was delayed but eventually more intense than compaction caused ...
Park Sungsu - - 2003
The environmental topology of complex structures is used by Escherichia coli to create traveling waves of high cell density, a prelude to quorum sensing. When cells are grown to a moderate density within a confining microenvironment, these traveling waves of cell density allow the cells to find and collapse into ...
Mittal Nikhil - - 2003
Cells of Escherichia coli under conditions of certain cellular stresses excrete attractants. Cells of chemotactic strains respond to these excreted signaling molecules by moving up their local concentration gradients and forming different types of stable multicellular structures. Multicellular clusters are the simplest among these structures. Fluorescence microscopy was used to ...
Bennett Richard J - - 2003
Candida albicans, the most prevalent fungal pathogen of humans, has recently been shown to undergo mating. Here we describe a mating pheromone produced by C. albicans alpha cells and show that the gene which encodes it (MFalpha) is required for alpha cells, but not a cells, to mate. We also ...
Howell Scott J - - 2003
The lumen of the human colon is heavily colonized with microbes, but infections across its epithelial surface are infrequent. To address the hypothesis that antimicrobial polypeptides contribute to the barrier function of colonic epithelial cells, we examined cellular extracts from non-inflamed colonic mucosa using an antimicrobial assay. This approach yielded ...
Chen Tianhong - - 2003
We report an enzyme-based method for the in situ entrapment of cells within a biopolymeric hydrogel matrix. Specifically, we used a calcium-independent microbial transglutaminase that is known to cross-link proteins and observed that it catalyzes the formation of gels from a pre-gel solution containing 10% gelatin and E. coli cells. ...
Kawarai T - - 2004
To improve the efficiency of sterilization by high hydrostatic pressure treatment (HPT), it is desirable to know the biochemical process of bacteria most sensitive to the treatment. We investigated growth properties after release from HPT of exponentially growing Escherichia coli K-12 cells. We observed growth retardation after treatment (30 min ...
Hassan A N - - 2003
The influence of surfactant hydrophobicity on detachment of Escherichia coli O157:H7 from lettuce was determined. Lettuce pieces inoculated with the pathogen were rinsed with Tween and Span surfactants of different hydrophobicity. Of the Tweens, only Tween 85, the Tween with the lowest hydrophile/lipophile balance (HLB), significantly detached the pathogen from ...
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