Publications
Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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some structures and processes of human epithelial cells involved in uptake of enterohemorrhagic escherichia coli o157:h7 strains. | several enterohemorrhagic escherichia coli (ehec) strains of serotype o157:h7 isolated from patients with hemorrhagic colitis, ischemic colitis, or hemolytic uremic syndrome were all found to be able to invade certain human epithelial cell lines in vitro. their ability to gain entry into epithelial cells was compared with those of known invasive shigella flexneri and salmonella typhi strains and the noninvasive e. coli strain hb101 in invasion assays utilizing gentamicin to kill extracellular ba ... | 1994 | 7523304 |
avirulence of rough mutants of shigella flexneri: requirement of o antigen for correct unipolar localization of icsa in the bacterial outer membrane. | mutations in the lipopolysaccharide (lps) of shigella spp. result in attenuation of the bacteria in both in vitro and in vivo models of virulence, although the precise block in pathogenesis is not known. we isolated defined mutations in two genes, galu and rfe, which directly affect synthesis of the lps of s. flexneri 2a, in order to determine more precisely the step in virulence at which lps mutants are blocked. the galu and rfe mutants invaded hela cells but failed to generate the membrane pro ... | 1995 | 7528731 |
molecular, genetic, and topological characterization of o-antigen chain length regulation in shigella flexneri. | the rfb region of shigella flexneri encodes the proteins required to synthesize the o-antigen component of its cell surface lipopolysaccharides (lps). we have previously reported that a region adjacent to rfb was involved in regulating the length distribution of the o-antigen polysaccharide chains (d. f. macpherson et al., mol. microbiol. 5:1491-1499, 1991). the gene responsible has been identified in escherichia coli o75 (called rol [r. a. batchelor et al., j. bacteriol. 173:5699-5704, 1991]) a ... | 1995 | 7532168 |
reiter's syndrome and reactive arthritis: a current view. | this paper reviews advances in the understanding of the pathogenesis of reactive arthritis that have occurred over the last decade. inflammatory aseptic joint disease has been linked with prior infection initiated by many different species of microorganisms. the presence of intra-articular bacterial antigens has now been firmly established with the demonstration of bacteria, bacterial fragments, dna, rna, and bacterial lipopolysaccharide in joints of patients with reactive arthritis. chlamydia t ... | 1994 | 7534942 |
invasion of epithelial cells by shigella flexneri induces tyrosine phosphorylation of cortactin by a pp60c-src-mediated signalling pathway. | shigella flexneri causes bacillary dysentery in humans by invading epithelial cells of the colon. cell invasion occurs via bacterium-directed phagocytosis, a process requiring polymerization of actin at the site of bacterial entry. we show that invasion of hela cells by s.flexneri induces tyrosine phosphorylation of cortactin, a host cell protein previously identified as a cytoskeleton-associated protein tyrosine kinase (ptk) substrate for the proto-oncoprotein pp60c-src. immunolocalization expe ... | 1995 | 7540134 |
structural elucidation of the o-antigen lipopolysaccharide from two strains of plesiomonas shigelloides that share a type-specific antigen with shigella flexneri 6, and the common group 1 antigen with shigella flexneri spp and shigella dysenteriae 1. | sugar and methylation analyses of native polysaccharides together with one-dimensional 1h- and 13c-nmr spectroscopy revealed that the two polysaccharides from strains 22074 and 12254 of plesiomonas shigelloides are identical. the structure of the polysaccharide from strain 22074 was deduced from a uronic acid degradation and by nmr spectroscopy where heteronuclear multiple bond connectivity and two-dimensional nuclear overhauser effect spectroscopy experiments established the pentasaccharide rep ... | 1995 | 7544287 |
monoclonal immunoglobulin a antibody directed against serotype-specific epitope of shigella flexneri lipopolysaccharide protects against murine experimental shigellosis. | to determine the role of humoral mucosal immune response in protection against shigellosis, we have obtained a monoclonal dimeric immunoglobulin a (iga) antibody specific for shigella flexneri serotype 5a lipopolysaccharide (miga) and used a murine pulmonary infection model that mimics the lesions occurring in natural intestinal infection. adult balb/c mice challenged with 10(7) s. flexneri organisms developed a rapid inflammatory response characterized by polymorphonuclear cell infiltration aro ... | 1995 | 7544397 |
expression of shigella dysenteriae serotype 1 o-antigenic polysaccharide by shigella flexneri arod vaccine candidates and different s. flexneri serotypes. | the potential utility of shigella flexneri arod vaccine candidates for the development of bi- or multivalent vaccines has been explored by the introduction of the genetic determinants rfp and rfb for heterologous o antigen polysaccharide from shigella dysenteriae serotype 1. the serotype y vaccine strain sfl124 expressed the heterologous antigen qualitatively and quantitatively well, qualitatively in the sense of the o antigen polysaccharide being correctly linked to the s. flexneri lipopolysacc ... | 1995 | 7545156 |
live attenuated shigella flexneri mutants as vaccine candidates against shigellosis and vectors for antigen delivery. | up to now, no effective vaccine is available against shigellosis, a dysenteric syndrome caused by shigella, a gram-negative bacterium which invades the human colonic mucosa. about 40 years of research in the field have led to the conclusion that orally administered live shigella vaccine strains are more effective in eliciting protection than killed bacteria given parenterally. recently, the construction of promising new live attenuated vaccines has come with a better understanding of the fundame ... | 1995 | 7546655 |
[the resistance to antibiotics and chemotherapeutic agents of shigella strains isolated from hiv-seropositive children]. | 1995 | 7549258 | |
functional conservation of the secretion and translocation machinery for virulence proteins of yersiniae, salmonellae and shigellae. | virulent bacteria of the genera yersinia, shigella and salmonella secrete a number of virulence determinants, yops, ipas and sips respectively, by a type iii secretion pathway. the ipab protein of shigella flexneri was expressed in yersinia pseudotuberculosis and found to be secreted under the same conditions required for yop secretion. likewise, yope was secreted by the wild-type strain lt2 of salmonella typhimurium, but yope was not secreted by the isogenic inva mutant. secretion of both ipab ... | 1995 | 7556059 |
recognition of three epitopic regions on invasion plasmid antigen c by immune sera of rhesus monkeys infected with shigella flexneri 2a. | the invasive ability of shigella spp. is correlated with the expression of several plasmid-encoded proteins, including invasion plasmid antigen c (ipac). by characterizing the antigenic structure of ipac with monoclonal antibodies and convalescent-phase sera, it may be possible to determine the physical location of specific epitopes as well as the involvement of epitopes in a protective immune response or the host's susceptibility to disease. by using overlapping octameric synthetic peptides, wh ... | 1995 | 7558301 |
evaluation of commercial antisera for shigella serogrouping. | shigella serogrouping antisera from six companies (becton dickinson, denka, difco, murex, roach, and sanofi-pasteur) intended for the slide agglutination test and those of the wellcolex colour shigella latex agglutination test were evaluated to identify quality products for shigella identification. forty-six reference shigella strains (one for each serotype and species), 50 clinical strains (21 s. flexneri, 21 s. sonnei, 4 s. dysenteriae, 4 s. boydii) representing the most prevalent species and ... | 1995 | 7559936 |
comparison of preservation media for storage of stool samples. | transportation of clinical samples and long-term recoverability of pathogens are critical to epidemiological studies, particularly when conditions do not permit immediate processing. this study confirms that cary-blair medium (cb) is suitable for the preservation of salmonella and shigella isolates for more than 2 weeks at 25, 4, or -70 degrees c. campylobacter jejuni was not recovered after 2 days of storage in cb at 25 degrees c when an inoculum of 12 x 10(8) cells per ml was used. lower tempe ... | 1995 | 7559972 |
enhanced secretion through the shigella flexneri mxi-spa translocon leads to assembly of extracellular proteins into macromolecular structures. | genes required for entry of shigella flexneri into epithelial cells in vitro are clustered in two adjacent loci, one of which encodes secretory proteins, the ipaa-d proteins, and the other their dedicated secretion apparatus, the mxi-spa translocon. ipa secretion, which is induced upon contact of bacteria with epithelial cells, is prevented during growth in vitro. here, we show that ipab and ipad mutations lead to enhanced secretion of a set of about 15 proteins. these extracellular proteins and ... | 1995 | 7565091 |
attenuated shigella as a dna delivery vehicle for dna-mediated immunization. | direct inoculation of dna, in the form of purified bacterial plasmids that are unable to replicate in mammalian cells but are able to direct cell synthesis of foreign proteins, is being explored as an approach to vaccine development. here, a highly attenuated shigella vector invaded mammalian cells and delivered such plasmids into the cytoplasm of cells, and subsequent production of functional foreign protein was measured. because this shigella vector was designed to deliver dna to colonic mucos ... | 1995 | 7569980 |
structural analysis of invasion plasmid antigen d (ipad) from shigella flexneri. | invaison plasmid antigen d (ipad) and water-extracted outer-membrane proteins (omps) from shigella flexneri were used to investigate some of the structural relationships of this pathogen's invasions. extracellular presentation of the three invasion plasmid antigens (ipa) b, c, and d is required for the s. flexneri invasive phenotype; however, little is known of the structural properties of these essential virulence components. biochemical data suggest ipab, c, and d present in s. flexneri omps f ... | 1995 | 7575570 |
the complete hrp gene cluster of pseudomonas syringae pv. syringae 61 includes two blocks of genes required for harpinpss secretion that are arranged colinearly with yersinia ysc homologs. | pseudomonas syringae pv. syringae 61 contains a 25-kb hrp cluster that is sufficient to elicit the hypersensitive response (hr) in nonhost plants. previous studies have shown that mutations in complementation groups viii, ix, and xi in the hrp cluster abolished the ability of the bacterium to cause the hr. the sequence of a 3.7-kb smai-ssti fragment covering groups viii and ix now reveals five open reading frames (orfs) in the same transcript, designated as hrpu, hrpw, hrpo, hrpx, and hrpy, and ... | 1995 | 7579617 |
sequence and analysis of the o antigen gene (rfb) cluster of escherichia coli o111. | the o antigens found in salmonella enterica (se) and escherichia coli (ec) show a great deal of diversity, and only three structures are known to be common to both genera. two of them contain the 3,6-dideoxyheoxse colitose, not found in other serogroups of the two species. the first of these is common to ec o111 and se o:35 (sv adelaide); the other is found in both ec o55 and se o:50 (sv greenside). the genes specific for the synthesis of o antigen are generally located in the rfb gene cluster a ... | 1995 | 7590310 |
development of an improved animal model of shigellosis in the adult rabbit by colonic infection with shigella flexneri 2a. | rabbits are not usually susceptible to intestinal shigella infection without extensive pretreatment, including starvation and administration of antimicrobial, antimotility, and toxic agents (carbon tetrachloride). most animals infected this way die rapidly and do not always develop colonic lesions and signs of dysentery. we describe here a successful experimental infection in the adult rabbit which does not require preparatory treatment and which reproduced characteristic features of human shige ... | 1995 | 7591070 |
identification and cloning of a novel plasmid-encoded enterotoxin of enteroinvasive escherichia coli and shigella strains. | we have employed a molecular genetic approach to characterize the nature of enteroinvasive escherichia coli (eiec) enterotoxic activity, as previously observed in ussing chambers (a. fasano, b.a. kay, r.g. russell, d.r. maneval, jr., and m.m. levine, infect. immun. 58:3717-3723, 1990). the screening of tnphoa mutants of eiec yielded a single insertion mutant which had significantly reduced levels of enterotoxic activity in the ussing chamber assay. dna flanking the insertion was used as a probe ... | 1995 | 7591128 |
prevalence of shigella enterotoxin 1 among shigella clinical isolates of diverse serotypes. | shigella enterotoxin 1 (shet1) is a novel, iron-dependent, toxin encoded by chromosomal genes (set1). to determine the prevalence of this enterotoxin, 172 shigella clinical isolates (and 10 enteroinvasive escherichia coli [eiec]) from distant areas worldwide, representing all 4 groups and 45 serotypes of shigella, were screened for set1 by dna colony hybridization and polymerase chain reaction amplification. set1 was present in all 22 shigella flexneri 2a strains tested but was rare in isolates ... | 1995 | 7594690 |
shigella flexneri surface protein icsa is sufficient to direct actin-based motility. | shigella flexneri is a gram-negative bacterial pathogen that can grow directly in the cytoplasm of infected host cells and uses a form of actin-based motility for intra- and intercellular spread. moving intracellular bacteria are associated with a polarized "comet tail" composed of actin filaments. icsa, a 120-kda outer membrane protein necessary for actin-based motility, is located at a single pole on the surface of the organism, at the junction with the actin tail. here, we demonstrate that st ... | 1995 | 7604035 |
cell movement tale told by bacterial tail protein. | 1995 | 7604275 | |
comparative analysis of extreme acid survival in salmonella typhimurium, shigella flexneri, and escherichia coli. | several members of the family enterobacteriaceae were examined for differences in extreme acid survival strategies. a surprising degree of variety was found between three related genera. the minimum growth ph of salmonella typhimurium was shown to be significantly lower (ph 4.0) than that of either escherichia coli (ph 4.4) or shigella flexneri (ph 4.8), yet e. coli and s. flexneri both survive exposure to lower ph levels (2 to 2.5) than s. typhimurium (ph 3.0) in complex medium. s. typhimurium ... | 1995 | 7608084 |
shigella flexneri adherence to and multiplication in coxsackie b1 virus-infected hep-2 cells. | coxsackie b1 virus infection enhances the susceptibility of in vitro cultured hep-2 cells to invasiveness by shigella flexneri. we have studied the effect of viral infection on two phases of the invasiveness. only a minor part was mediated by enhanced bacterial adherence to the cells, and the intracellular multiplication was unaffected by the virus. enhanced adherence was not dependent on the presence of the gene product of the 140 md virulence associated plasmid. our data indicate that enhanced ... | 1995 | 7612255 |
[the colicin selection of the s forms of representatives in the enterobacteriaceae family]. | a method based on a lower sensitivity of s forms to colicines, in comparison with r forms, was used for the selection of s forms of bacteria from dissociated cultures of e. coli o.124:k72, s. sonnei, and s. flexneri. the cultures are inoculated in nutrient agar from the external segment of the zone of bacterial growth suppression by colicines d, e1, and v+m, where the content of s forms is relatively higher at the expense of death of r forms. the content of s forms in the resultant cultures of d ... | 1995 | 7620780 |
shigella infection induces cellular activation of t and b cells and distinct species-related changes in peripheral blood lymphocyte subsets during the course of the disease. | immunophenotypic changes in peripheral blood lymphocytes (t, b, and nk cells) in patients during shigellosis was characterized by using triple-color flow cytometry. eleven shigella dysenteriae 1-infected adult patients (sdip), 11 shigella flexneri-infected adult patients (sfip), 15 age- and sex-matched healthy controls from bangladesh (c-b), and 15 healthy volunteers from sweden (v-s) were studied. in sdip and sfip, a significant increase in the cd45ro+ cells in both cd4+ and cd8+ t cells were s ... | 1995 | 7622216 |
the hrp gene locus of pseudomonas solanacearum, which controls the production of a type iii secretion system, encodes eight proteins related to components of the bacterial flagellar biogenesis complex. | five transcription units of the pseudomonas solanacearum hrp gene cluster are required for the secretion of the hr-inducing popa1 protein. the nucleotide sequences of two of these, units 1 and 3, have been reported. here, we present the nucleotide sequence of the three other transcription units, units 2, 4 and 7, which are together predicted to code for 15 hrp genes. this brings the total number of hrp proteins encoded by these five transcription units to 20, including hrpb, the positive regulat ... | 1995 | 7623665 |
virg, a yersinia enterocolitica lipoprotein involved in ca2+ dependency, is related to exsb of pseudomonas aeruginosa. | pathogenic yersiniae require ca2+ for growth at 37 degrees c. they harbor closely related plasmids of about 70 kb that are essential for virulence. at 37 degrees c and in the absence of ca2+ ions, these plasmids cause a decrease in growth rate and the release of large amounts of proteins called yops. here we describe the virg gene of yersinia enterocolitica; virg is located just upstream of the virf gene, which encodes the transcriptional activator of some plasmid virulence factors. analysis of ... | 1995 | 7635810 |
role of interleukin-1 in the pathogenesis of experimental shigellosis. | the effect of human recombinant interleukin-1 receptor antagonist on intestinal inflammation, tissue destruction, and bacterial invasion during experimental shigellosis caused by shigella flexneri was studied in the rabbit-ligated loop infection model. intravenous infusion of the inhibitor at a dose of 2 mg/kg per h, was initiated 30 min before intestinal loops were ligated and infected, and continued during the 8-h period of infection. the animals treated with il-1 receptor antagonist showed a ... | 1995 | 7635983 |
evaluation of the safety, immunogenicity, and efficacy in healthy adults of four doses of live oral hybrid escherichia coli-shigella flexneri 2a vaccine strain ecsf2a-2. | in previous trials, live invasive escherichia coli-shigella flexneri 2a hybrid vaccine candidate ecsf2a-2, administered to adult volunteers as 3 doses of ca. 2 x 10(9) colony forming units (c.f.u.) spaced over one week, induced fever and/or diarrhea in 11% of subjects and provided only limited protection (36% efficacy) against illness following challenge with virulent s. flexneri 2a. we sought to improve the clinical safety of this vaccine by administering a lower inoculum, and to enhance protec ... | 1995 | 7639017 |
h-ns regulation of virulence gene expression in enteroinvasive escherichia coli harboring the virulence plasmid integrated into the host chromosome. | we have previously shown that integration of the virulence plasmid pinv into the chromosome of enteroinvasive escherichia coli and of shigella flexneri makes these strains noninvasive (c. zagaglia, m. casalino, b. colonna, c. conti, a. calconi, and m. nicoletti, infect. immun. 59:792-799, 1991). in this work, we have studied the transcription of the virulence regulatory genes virb, virf, and hns (virr) in wild-type enteroinvasive e. coli hn280 and in its pinv-integrated derivative hn280/32. whil ... | 1995 | 7642498 |
enteropathogenic escherichia coli contains a putative type iii secretion system necessary for the export of proteins involved in attaching and effacing lesion formation. | enteropathogenic escherichia coli (epec) causes a characteristic histopathology in intestinal epithelial cells called the attaching and effacing lesion. although the histopathological lesion is well described the bacterial factors responsible for it are poorly characterized. we have identified four epec chromosomal genes whose predicted protein sequences are similar to components of a recently described secretory pathway (type iii) responsible for exporting proteins lacking a typical signal sequ ... | 1995 | 7644527 |
252cf-plasma desorption mass spectrometry analysis of lipids a obtained by an elimination reaction under mild conditions. | lipids a are the hydrophobic domains of bacterial endotoxic lipopolysaccharides. since they are responsible for most of the biological activities (both pathogenic and beneficial) of endotoxins, the characterization of their structure is crucial to the understanding of their mode of action. however, the inadequacy of existing methods for preparing certain lipids a has prompted us to devise a new, mild procedure which gives intact products. use was made of the special features of 252cf-plasma deso ... | 1995 | 7647366 |
[the immunomodulating capacity of shigella flexneri 2a bacteria that have lost their invasiveness plasmid]. | an immunosuppressive effect produced by live microbial cells of s. flexneri virulent plasmid-carrying strain 2a 516 (psf 140-) was shown in relation to the formation of splenic cells producing antibodies to heterologous antigen (sheep red blood cells). this effect was most pronounced at an early period (days 4-7) after the infection of mice. on the contrary, avirulent plasmid-free variant (psf 140-), genetically related to s. flexneri strain 2a 516, produced an immunostimulating effect at this p ... | 1995 | 7653137 |
epidemiological, clinical and microbiological features of shigellosis among hospitalized children in northern israel. | the epidemiological, clinical, and bacteriological aspects of shigellosis were studied in a population of hospitalized children in northern israel. during the 6-year period 1987-92, 262 children were hospitalized due to shigella infection. shigellosis represented 10% of pediatric admissions for diarrhea. admissions for the disease peaked during the summer and autumn. the median age of the patients was 3 years. shigella sonnei was isolated in 74% of patients and s. flexneri in 21%, compared with ... | 1995 | 7660077 |
pivmecillinam resistant shigella infections in rural bangladesh. | 1995 | 7660498 | |
identification of a global repressor gene, rsma, of erwinia carotovora subsp. carotovora that controls extracellular enzymes, n-(3-oxohexanoyl)-l-homoserine lactone, and pathogenicity in soft-rotting erwinia spp. | the production of extracellular enzymes such as pectate lyase (pel), polygalacturonase (peh), cellulase (cel), and protease (prt) is activated by the cell density (quorum)-sensing signal, n-(3-oxohexanoyl)-l-homoserine lactone (hsl); plant signals; and aep genes during postexponential growth of erwinia carotovora subsp. carotovora 71. studies with mutants of e. carotovora subsp. carotovora 71 derepressed in exoenzyme production led to the identification of a negative regulator gene, rsma (rsm, r ... | 1995 | 7665490 |
1995 flemming lecture. dna topology and the global control of bacterial gene expression: implications for the regulation of virulence gene expression. | 1995 | 7670631 | |
genetic and biosynthetic aspects of shigella flexneri o-specific lipopolysaccharides. | 1993 | 7680623 | |
the synthesis of chemically modified disaccharide derivatives of the shigella flexneri y polysaccharide antigen. | disaccharide analogs related to the 2-acetamido-2-deoxy-3-o-(alpha-l- rhamnopyranosyl)-beta-d-glucopyranose element of the shigella flexneri y polysaccharide antigen have been synthesized and used to map the binding site of murine monoclonal antibodies gc-4 and sya/j6 by solid-phase inhibition assays. n-acetyl, n-trifluoroacetyl and n-benzyloxycarbonyl derivatives of methyl-2-amino-4,6-o-benzylidene-2-deoxy-beta-d-glucopyranoside 1, 3, and 4 were glycosylated by rhamnopyranosyl bromide and thiog ... | 1993 | 7681359 |
[reactive arthritis associated bacteria as the etiology of undifferentiated oligoarthritis]. | undifferentiated oligoarthritis (uoa) resembles clinically reactive arthritis (rea), but does not fulfill the diagnostic criteria. in 46 patients with uoa, in 16 with rea, and in 15 with rheumatoid arthritis (ra) the humoral and cellular immune response to the rea-associated bacteria chlamydia trachomatis, yersinia enterocolitica, shigella flexneri, salmonella enteritidis, campylobacter jejuni and borrelia burgdorferi was investigated in paired samples of synovial fluid and peripheral blood. an ... | 1993 | 7682746 |
characterization of b-cell epitopes on ipab, an invasion-associated antigen of shigella flexneri: identification of an immunodominant domain recognized during natural infection. | the invasion plasmid antigen b (ipab), a 62-kda plasmid-encoded protein associated with the ability of shigellae to invade epithelial cells, is the bacterial antigen most strongly and consistently recognized by the host during infection. the strong systemic and mucosal immune responses observed against this invasin prompted us to map its b-cell epitopes. for this purpose, ipab was first overexpressed in shigella flexneri and used to raise rabbit polyclonal antiserum and murine monoclonal antibod ... | 1993 | 7689541 |
transcriptional control of the invasion regulatory gene virb of shigella flexneri: activation by virf and repression by h-ns. | expression of invasion genes encoded by the large 230-kb plasmid of shigella flexneri is controlled by the virb gene, which is itself activated by another regulator, virf. transcription of the invasion genes is temperature regulated, since they are activated in bacteria grown at 37 but not at 30 degrees c. recently, we have shown that the thermoregulated expression of invasion genes is mediated by thermal activation of virb transcription (t. tobe, s. nagai, b. adler, m. yoshikawa, and c. sasakaw ... | 1993 | 7691791 |
[synovial cellular immune response to bacterial pathogens in patients with chronic juvenile arthritis]. | juvenile chronic arthritis is a heterogenous disease with an ill-defined pathogenesis. in our study, synovial fluid (sf) and peripheral blood (pb) of 70 children with oligoarthritis were investigated; bacteria-specific lymphocyte proliferation and antibodies to arthritogenic bacteria were determined. specific cellular immune responses in sf but not in pb were found in 4/7 patients with either lyme- or reactive arthritis (60%). in comparison, in subgroup jca ii (n = 45) encompassing mainly elder ... | 1993 | 7692686 |
association between reactive arthritis and antecedent infection with shigella flexneri carrying a 2-md plasmid and encoding an hla-b27 mimetic epitope. | to determine whether shigella flexneri strains that cause enteric infection and are associated with reactive arthritis (rea) carry a 2-md plasmid, phs-2, which encodes an hla-b27 mimetic epitope. | 1993 | 7692858 |
synthesis of chlorodeoxy trisaccharides related to the shigella flexneri y polysaccharide. | chloromethoxylation of di-o-acetyl-l-rhamnal has been employed as a convenient route to methyl 3,4-di-o-acetyl-2-chloro-2-deoxy-alpha-l-rhamnopyranoside 7, which was converted into an ethyl thioglycoside 10, suitable for use as a glycosyl donor. it and a disaccharide analogue 20 were effective donors in n-iodosuccinimide-triflic acid promoted glycosylations of a 2-acetamido-2-deoxy-d-glucopyranoside acceptor 22. chlorodeoxy saccharides have previously been shown to be suitable derivatives to pro ... | 1993 | 7693346 |
high frequency of strains multiply resistant to ampicillin, trimethoprim-sulfamethoxazole, streptomycin, chloramphenicol, and tetracycline isolated from patients with shigellosis in northeastern brazil during the period 1988 to 1993. | the occurrence and antimicrobial resistance pattern of shigella isolates obtained from persons in community and hospital-based studies of diarrhea and matched controls in northeastern brazil were studied. the isolation rate of shigella spp. from patients with diarrhea during 1988 to 1993 varied from 4.5% (26 of 575) for the urban community of gonçalves dias to 6.7% (12 of 179) and 5.9% (7 of 119) for hospital infantil and hospital universitário, respectively. of the 55 shigella isolates (45 from ... | 1995 | 7695319 |
[the epithelial proliferative activity of the mucosa of the large intestine in dysentery patients at the acute period of the disease depending on the expression of morphological changes]. | the dependence of proliferative activity on the degree of histomorphological changes in colonic mucosa of patients with dysentery was studied histoautoradiographically in colonic biopsies. morphological changes were evaluated according to n. b. shalygina's schema (catarrhal, exudative, erosive or ulcerous inflammation) a 2.5-3-fold increase of the labelled nuclei index (lni) and label intensity (li) was found in the catarrhal inflammation. lni was increased 1.2-fold and li 1.5-fold in cases of o ... | 1994 | 7695494 |
genetic analysis of the rfbx gene of shigella flexneri. | analysis of the nucleotide sequence of the rfbx gene of shigella flexneri revealed that it contained a high proportion of rare codons, as previously observed in the analysis of the o-antigen polymerase-encoding gene rfc [morona et al., j. bacteriol. 176 (1994) 733-747]. the rfbx gene encodes a hydrophobic, 46-kda protein, with 12 potential transmembrane-spanning domains, that shows structural homology with gene products encoded in many rfb regions, and with orf0416 of the rff region of escherich ... | 1995 | 7698674 |
a conformationally homogeneous combinatorial peptide library. | in search for a rational way to convert the information encoded in peptide structures into peptidomimetics, major progress could be made by coupling the power of selection methods, now enormously increased in number as a result of the development of combinatorial peptide libraries, with the rational design of structure-inducing templates for the selectable sequences. the availability of libraries of peptides with predetermined structure would enable selection-driven peptidomimetic design, whereb ... | 1995 | 7707366 |
fecal excretion of leukotriene c4 during human disease due to shigella dysenteriae. | fecal excretion of leukotriene c4 was determined in 26 individuals with dysentery and in 19 healthy controls. of the patients, five were infected with shigella dysenteriae type 1, 15 were infected with shigella flexneri, two were infected with shigella boydii, and four were infected with shigella sonnei. three of the healthy controls were infected with non-dysenteriae shigellae. all isolates of shigella dysenteriae type 1 produced shiga toxin; the other strains were not toxigenic. patients with ... | 1995 | 7714683 |
cell-to-cell spread of shigella flexneri: exploitation of the host cytoskeleton. | 1995 | 7714693 | |
[bacteriostasis of rhizoma coptidis combined with trimethoprim (tmpo)]. | the agar-dilution method was adopted to study contrastively the bacteriostasis of rhizoma coptidis and tmp, and also of the two drugs in combination. the results indicate that the combination works in good cooperation against escherichia coli, bacillus pyocyaneus, staphylococcus aureus, shigella flexneri and s. dysenteriae. | 1994 | 7718141 |
shigella flexneri-hela cell interactions: a putative role for host cell protein kinases. | epithelial cell invasion has been shown to be a prerequisite for shigella flexneri virulence. recently, we have documented the induction of transcription factor dna binding activities as a result of s. flexneri challenge of hela cells. in this report, we show that hela cells challenged with s. flexneri display differences in phosphotyrosine-containing proteins. these changes are detected as early as 5 min post-challenge. challenge with a noninvasive ipab mutant strain resulted in the induction o ... | 1995 | 7719286 |
cytoskeletal rearrangements and the functional role of t-plastin during entry of shigella flexneri into hela cells. | shigella flexneri is an enteroinvasive bacterium which causes bacillary dysentery in humans. a major feature of its pathogenic potential is the capacity to invade epithelial cells. shigella entry into epithelial cells is considered a parasite-induced internalization process requiring polymerization of actin. here we describe the cytoskeletal rearrangements during s. flexneri invasion of hela cells. after an initial contact of the bacterium with the cell surface, distinct nucleation zones of heav ... | 1995 | 7721941 |
a focal adhesion factor directly linking intracellularly motile listeria monocytogenes and listeria ivanovii to the actin-based cytoskeleton of mammalian cells. | the surface-bound acta polypeptide of the intracellular bacterial pathogen listeria monocytogenes is the sole listerial factor needed for recruitment of host actin filaments by intracellularly motile bacteria. here we report that following listeria infection the host vasodilator-stimulated phosphoprotein (vasp), a microfilament- and focal adhesion-associated substrate of both the camp- and cgmp-dependent protein kinases, accumulates on the surface of intracytoplasmic bacteria prior to the detect ... | 1995 | 7729410 |
antibody and cytokine responses in a mouse pulmonary model of shigella flexneri serotype 2a infection. | a murine pulmonary model was used to study the mucosal immune response to shigella flexneri serotype 2a infection. inoculation of balb/cj mice with shigellae via the intranasal route resulted in bacterial invasion of bronchial and alveolar epithelia with concomitant development of acute suppurative bronchiolitis and subsequent development of lethal pneumonia. the pathology of pulmonary lesions resembled the colitis that characterizes shigellosis in humans and primates. significant protection aga ... | 1995 | 7729907 |
[regarding the shigella flexneri 4 strains isolated in recent years]. | a total of 38 strains of shigella flexneri 4, 14 of which were subserotype 4a but 24 of which were of an undecided subserotype, isolated in recent years, were studied for their biochemical and serological characteristics, and drug susceptibility. among the biochemical characteristics examined, 21 of the 38 strains (55.3%) were mannitol negative biotype and utilized sodium acetate, meanwhile, 17 of the mannitol positive strains did not utilize sodium acetate. the results of serological tests show ... | 1995 | 7745304 |
[diarrhea, dysentery, cholera, new frontiers?]. | 1994 | 7746137 | |
the pho regulon of shigella flexneri. | growth of escherichia coli k-12 in low-phosphate conditions results in the induction of the synthesis of many proteins, including the outer membrane porin phoe, alkaline phosphatase, and the pst system for the transport of phosphate (p1). this response is controlled by a two-component regulatory system of which phob and phor are the response-regulator and the sensor/kinase, respectively. when shigella flexneri was starved for p1, neither phoe nor alkaline phosphatase was produced. however, induc ... | 1995 | 7746146 |
acid tolerance of enterohemorrhagic escherichia coli. | enterohemorrhagic escherichia coli (ehec) strains were tested for their ability to survive in acid ph at 37 degrees c. no loss of viability was observed in an o157:h7 ehec strain (atcc 43895) at ph levels of 3.0 and 2.5 for at least 5 h. the level of acid tolerance of most ehec isolates was very high, similar to that of shigella flexneri strains. the acid tolerance was dependent on the growth phase and ph of the growth medium. | 1995 | 7747983 |
actin-based bacterial motility. | listeria monocytogenes and other bacterial pathogens move in the host cell cytoplasm, propelled by continuous actin assembly at one pole of the bacterium. this actin-based motility requires the presence of the bacterial proteins acta on l. monocytogenes and icsa on shigella flexneri. there have been several major discoveries in the past year: the discovery of the polar distribution of acta and icsa on the bacterial surface; the demonstration that bacterial acta is phosphorylated in infected host ... | 1995 | 7755995 |
potency of endotoxin from bicarbonate dialysate compared with endotoxins from escherichia coli and shigella flexneri. | endotoxin is a potent activator of the complement system and other host immunoregulators, including the cytokines, tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6. in this study, the potency of an endotoxin from bicarbonate dialysate was compared with endotoxins from two enteric microorganisms, shigella flexneri and escherichia coli. endotoxin concentrations were standardized for the three endotoxins by use of the limulus amebocyte lysate turbidimetric assay. endotoxin potency ... | 1995 | 7756598 |
[the phagocytic activity of the blood neutrophils in monkeys undergoing multiple irradiation]. | the study of pathogenic activity of neutrophils under chronic low-dose irradiation (total doses were 0.84-24.99 gy) was carried out. the stage of phase changes was followed by a stable increase in neutrophil phagocytic activity, according to absorbing capacity, at relatively high total doses of irradiation. the data obtained were considered as a defence-compensatory reaction caused by decrease and depression of digestive capacity of phagocytes. | 1995 | 7757188 |
disulfide oxidoreductase activity of shigella flexneri is required for release of ipa proteins and invasion of epithelial cells. | secretion of ipab, ipac, and ipad proteins of shigella flexneri, essential for the invasion of epithelial cells, requires a number of proteins encoded by the spa and mxi loci on the large plasmid. introduction of dsba::tn5 into s.flexneri from escherichia coli k-12 reduced invasiveness, which resulted from a decrease in the capacity to release ipab, ipac, and ipad proteins into the external medium. examination of the surface-presented ipa proteins of the dsba mutant, however, revealed ipa protei ... | 1995 | 7761426 |
safety and immunogenicity study of the auxotrophic shigella flexneri 2a vaccine sfl1070 with a deleted arod gene in adult swedish volunteers. | the live auxotrophic shigella flexneri 2a vaccine strain sfl1070 with a deleted arod gene was given orally to 37 adult swedish volunteers who received three doses within 5 days. each dose comprised 1 x 10(5) (n = 9), 1 x 10(7) (n = 10), 1 x 10(8) (n = 9) or 1 x 10(9) (n = 9) c.f.u. s. flexneri sfl1070. one volunteer vaccinated with 1 x 10(7) and three vaccinated with 1 x 10(8) c.f.u. reported mild gastrointestinal symptoms after the first dose. vaccination with 1 x 10(9) c.f.u. caused abdominal ... | 1995 | 7762285 |
regulated underexpression and overexpression of the flin protein of escherichia coli and evidence for an interaction between flin and flim in the flagellar motor. | the flin protein of escherichia coli is essential for the assembly and function of flagella. here, we report the effects of regulated underexpression and overexpression of flin in a flin null strain. cells that lack the flin protein do not make flagella. when flin is underexpressed, cells produce relatively few flagella and those made are defective, rotating at subnormal, rapidly varying speeds. these results are similar to what was seen previously when the flagellar protein flim was underexpres ... | 1995 | 7768859 |
shigella enterotoxin 1: an enterotoxin of shigella flexneri 2a active in rabbit small intestine in vivo and in vitro. | culture filtrates of shigella flexneri 2a strain m4243 grown in iron-depleted medium, caused significant fluid accumulation in rabbit ileal loops. also, when tested in ussing chambers, a greater rise in potential difference and short circuit current was seen with such filtrates compared with the medium control. analogous filtrates from two m4243 derivatives lacking the 140-md invasiveness plasmid (either m4243avir or bs103) retained 60-65% of the wild-type enterotoxic activity. ultrafiltration a ... | 1995 | 7769126 |
identification of bacterial genes that contribute to survival and growth in an intracellular environment. | 1995 | 7773592 | |
[the role of the outer membrane proteins, determined by the shigella flexneri invasiveness plasmid, in inducing cellular immune reactions]. | fractions of s.flexneri 2a 516 outer membrane proteins determined by plasmid psf140 have been shown to possess immunomodulating activity and to be capable of influencing the intensity of hematopoiesis, manifested by the stimulation of endocolony formation, the increase of the amount of splenic colony-forming units in the marrow, the increase of the pool of proliferating splenic colony-forming units of the marrow and their intensive migration into the blood. outer membrane proteins have been show ... | 1995 | 7778372 |
[new methodological approaches to the use of the pha reaction in determining anti-shigella antibodies]. | pronounced correlation between the titers of hemagglutinating antibodies to different types of shigellae and other bacteria in healthy persons and in sick persons of control groups has been established. on the basis of this regularity a new approach to the use of the passive hemagglutination test in shigellosis, taking into account the ratio of antibody titers to different shigella types, has been developed. this essentially increases the sensitivity and specificity of the test, thus making it p ... | 1995 | 7778383 |
[bactericidal effect of hydrated lime in aqueous solution]. | this study determined the bactericidal effect of the supernatants of saturated solutions of common lime and of micronized calcium hydroxide (ca(oh)2) (1500 mg/l), which was used as a control, compared with disinfectants made of solutions of 0.33% colloidal silver (0.0016 mg/l), toluene sulfachloramine (41 mg/l) with sodium bicarbonate (9 mg/l), and sodium hypochlorite (5 mg/l). the test involved four strains of vibrio cholerae 01, v. parahaemolyticus, escherichia coli, salmonella typhimurium, sh ... | 1995 | 7779285 |
contact of shigella with host cells triggers release of ipa invasins and is an essential function of invasiveness. | the invasion of colonic epithelial cells by shigella, an early essential step for causing bacillary dysentery, is mediated by the ipab, ipac and ipad proteins. secretion of the ipa proteins from shigella requires functions encoded by the mxi and spa loci. in this study, we show that contact between the bacteria and epithelial cell triggers release of the ipa proteins into the external medium, which results in a rapid decrease in levels of ipa proteins presented on the cell surface. when the bact ... | 1995 | 7781600 |
a common-source outbreak of shigellosis involving a piped public water supply in northern thai communities. | we report an epidemiological investigation of an explosive common-source water-borne shigellosis outbreak traced to a piped public water system in northern thai communities. in august 1991, 242 cases of acute diarrhoeal illness occurred in sam ngao subdistrict, tak province. about 30% of the cases were culture-positive for multiresistant shigella flexneri 2a. the outbreak affected all age groups, with the highest attack rate (9.4%) in children < 5 years old. the first ten cases occurred during 1 ... | 1995 | 7783269 |
overexpression of the shigella flexneri genes coding for dna topoisomerase iv compensates for loss of dna topoisomerase i: effect on virulence gene expression. | introducing the escherichia coli topa20::tn10 allele to shigella flexneri results in osmotic sensitivity, a reduced growth rate, an increase in reporter plasmid supercoiling (all common to the e. coli mutants), an inability to grow on macconkey agar and a loss of virulence gene expression. e. coli mutants harbouring this topa allele often compensate for the loss of dna topoisomerase i by amplifying the genes coding for topoisomerase iv. unlike the e. coli topa mutants, derivatives of s. flexneri ... | 1995 | 7783621 |
acute bacterial diarrhoea in the emergency room: therapeutic implications of stool culture results. | empiric treatment with ciprofloxacin and norfloxacin has been recommended recently for patients with acute diarrhoeal disease. in a retrospective 6-month study period the results of stool cultures from 209 patients with acute diarrhoea admitted to the emergency room were analysed. seventy-eight cultures (37%) were positive for one or more bacteria. shigella was the most commonly isolated pathogen (68%). shigella sonnei comprised 72% and shigella flexneri 19% of all the bacterial isolates. while ... | 1994 | 7804582 |
persistence of local cytokine production in shigellosis in acute and convalescent stages. | shigella infection is accompanied by an intestinal activation of epithelial cells, t cells, and macrophages within the inflamed colonic mucosa. a prospective study was carried out to elucidate the cytokine pattern in shigella infection linked to development of immunity and eradication of bacteria from the local site and also to correlate the cytokine profile with histological severity. an indirect immunohistochemical technique was used to determine the production and localization of various cyto ... | 1995 | 7806368 |
caulobacter fliq and flir membrane proteins, required for flagellar biogenesis and cell division, belong to a family of virulence factor export proteins. | the caulobacter crescentus fliq and flir genes encode membrane proteins that have a role in an early step of flagellar biogenesis and belong to a family of proteins implicated in the export of virulence factors. these include the mopd and mope proteins from erwinia carotovora, the spa9 and spa29 proteins from shigella flexneri, and the yscs protein from yersinia pestis. inclusion in this family of proteins suggests that fliq and flir may participate in an export pathway required for flagellum as ... | 1995 | 7814323 |
functional conservation among members of the salmonella typhimurium inva family of proteins. | inva, which is essential for salmonella spp. to enter cultured epithelial cells, is a member of a family of proteins involved in either flagellar biosynthesis or the secretion of virulence determinants by a number of plant and mammalian pathogens. the predicted overall secondary structures of these proteins show significant similarities and indicate a modular construction with a hydrophobic amino-terminal half, consisting of six to eight potential transmembrane domains, and a hydrophilic carboxy ... | 1995 | 7822051 |
[epidemics and history: the berlin 1962 dysentery epidemic]. | 1994 | 7825366 | |
[the blood circulation of the rectal mucosa and the functional status of the rectal sphincter in acute infectious enterocolitis]. | significant decrease in the tone of the rectal mucosa venules was to be seen at the climax of acute proteus and klebsiella enterocolitis, as evidenced by examinations with the aid of rheorectograph and an analyzer of intracavitary motor activity, general blood supply to the intestinal segment under study being not compromised. the tone of the rectal mucous membrane arterioles is raised at the climax of acute dysentery caused by a flexner type of organism in erosive and haemorrhagic proctosigmoid ... | 1994 | 7831889 |
plasmid profiles of shigella and salmonella spp. isolated from diarrhoeic humans in ibadan, nigeria. | clinical isolates of shigella flexneri, s. dysentariae, s. boydii and salmonella spp. were screened for the presence of plasmids. most of the isolates harboured more than one plasmid ranging in molecular size from 1.3 to 36.1 x 10(6) daltons. very large plasmids were not encountered. | 1993 | 7839920 |
shigellosis in jordanian children: a clinico-epidemiologic prospective study and susceptibility to antibiotics. | during a 2-year prospective study of children hospitalized with gastroenteritis, shigellosis was detected in 66 cases (9 per cent of 726 admissions). the age group for peak shigella incidence was 1-4 years. the incidence increased from 8 per cent in 1991, to 11 per cent in 1992. shigella flexneri was the most common isolate (65 per cent), followed by shigella sonnei (17 per cent), shigella boydi (11 per cent), and shigella dysenteriae (7 per cent). at presentation, 44 per cent had watery diarrho ... | 1994 | 7853441 |
shigella flexneri: genetics of entry and intercellular dissemination in epithelial cells. | 1994 | 7859507 | |
thermoregulation of virb transcription in shigella flexneri by sensing of changes in local dna superhelicity. | transcription of the virb gene, a transcriptional regulator of invasion genes on the large plasmid of shigella flexneri, is strictly regulated by growth temperature; when bacteria are grown at 37 degrees c, virb transcription is highly activated, while at 30 degrees c the level of virb transcription decreases to less than 5% of that at 37 degrees c. transcription from the virb promoter is activated by virf, which is encoded on the same plasmid, in a dna superhelicity-dependent manner (t. tobe, m ... | 1995 | 7860590 |
[triple shigellosis in the same patient contracted during operation "turquoise" in rwanda]. | we report a case of shigellosis observed in a young french sanitary assistant, returning from a refugees camp in goma after a 5-week stay. three different species were isolated from stool samples: shigella flexneri, s. boydii and s. sonnei. this observation raises the matter of a chemical prophylaxis during a short stay in developing countries where sanitary conditions are poor. | 1994 | 7866040 |
antimicrobial resistance of shigella isolates causing traveler's diarrhea. | shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in spain. ampicillin and chloramphenicol resistance was more frequent in shigella flexneri (60 and 46%, respectively) than in shigella sonnei (32 and 18%, respectively) and in travel-related isolates (p < 0.05 and 0.04, respectively). of s. sonnei isolates from patients with tr ... | 1994 | 7872767 |
model for the combined effects of temperature, initial ph, sodium chloride and sodium nitrite concentrations on anaerobic growth of shigella flexneri. | a fractional factorial design was used to measure the effects and interactions of temperature (12-37 degrees c), initial ph (5.5-7.5), nacl (0.5-4.0%) and nano2 (0-1000 ppm) on the anaerobic growth kinetics of shigella flexneri in brain-heart infusion broth. anaerobic conditions were established by flushing the culture flasks with n2. a total of 375 cultures representing 124 variable combinations were analyzed, with growth curves being generated using the gompertz equation. growth rates decrease ... | 1994 | 7873336 |
[the role of the activity of pathogenic enterobacteria in inactivating the antibacterial constituent of interferon during phagocytosis]. | 1994 | 7879491 | |
[an evaluation of the efficacy of measures to limit the activity of the water factor in the transmission of shigellosis in the city of blagoveshchensk]. | 1994 | 7879538 | |
[an analysis of the plasmid profile of shigella flexneri strains used for obtaining vaccinal preparations]. | 1994 | 7879547 | |
[the etiological structure of shigellosis in monkeys of the adler nursery]. | 1994 | 7879549 | |
safety and immunogenicity of the oral e. coli k12-s. flexneri 2a vaccine (ecsf2a-2) among israeli soldiers. | a double-blind placebo-controlled study was carried out on the safety and immunogenicity of the oral shigella flexneri (ecsf2a-2) vaccine among israeli soldiers. sixty volunteers received the vaccine and 59 received placebo. fifty-three were given the full vaccine regimen (four doses). doses ranged between 4.1 x 10(8) and 1.1 x 10(9) c.f.u. visits to the unit clinic for mild gastrointestinal symptoms were common after the first dose in vaccinees (13%) as compared with placebo recipients (5%), bu ... | 1994 | 7887022 |
cleavage of shigella surface protein virg occurs at a specific site, but the secretion is not essential for intracellular spreading. | the large plasmid-encoded outer membrane protein virg (icsa) of shigella flexneri is essential for bacterial spreading by eliciting polar deposition of filamentous actin (f-actin) in the cytoplasm of epithelial cells. recent studies have indicated that virg is located at one pole on the surface of the bacterium and secreted into the culture supernatant and that in host cells it is localized along the length of the f-actin tail. the roles of these virg phenotypes in bacterial spreading still rema ... | 1995 | 7896693 |
the occurrence of duplicate lysyl-trna synthetase gene homologs in escherichia coli and other procaryotes. | the lysyl-trna synthetase (lysrs) system of escherichia coli k-12 consists of two genes, lyss, which is constitutive, and lysu, which is inducible. it is of importance to know how extensively the two-gene lysrs system is distributed in procaryotes, in particular, among members of the family enterobacteriaceae. to this end, the enterics e. coli k-12 and b; e. coli reference collection (ecor) isolates ec2, ec49, ec65, and ec68; shigella flexneri; salmonella typhimurium; klebsiella pneumoniae; ente ... | 1995 | 7896714 |
polymorphonuclear leukocyte transmigration promotes invasion of colonic epithelial monolayer by shigella flexneri. | in vivo and in vitro, shigella flexneri, an invasive pathogen of the human colon, cannot invade epithelial cells through their apical pole. to identify ways by which it may reach the cellular basolateral domain in order to invade, we have established an assay using the human colonic t-84 cell line grown on permeable filters. human pmn were added to the basal pole of the cells, and invasive shigellae to their apical pole. apical addition of bacteria induced strong transmigration of pmn, reaching ... | 1994 | 7906696 |
is protection against shigellosis induced by natural infection with plesiomonas shigelloides? | shigellosis due to shigella sonnei is rare among people growing up and living in developing countries; however, infections due to s sonnei becomes more common than those due to s flexneri as societies develop economically. the relation between risk of s sonnei infection and economic development may be explained by the exposure of developing-country populations to plesiomonas shigelloides. p shigelloides is often found in surface water, and one serotype (serotype 17) possesses a cell-wall lipopol ... | 1994 | 7910890 |
construction and characterization of attenuated delta aroa delta virg shigella flexneri 2a strain cvd 1203, a prototype live oral vaccine. | we engineered an oral shigella vaccine prototype that can invade intestinal epithelial cells but cannot undergo extensive intracellular replication or extend to adjacent epithelial cells. strain cvd 1203, derived from wild-type shigella flexneri 2a by introducing deletions in chromosomal aroa and invasion plasmid virg, was highly attenuated in the sereny test. two 10(9)-cfu orogastric doses (2 weeks apart) stimulated production of secretory immunoglobulin a antibodies to s. flexneri 2a and prote ... | 1994 | 7927802 |