the stability of o-antigen plasmid is determined by a chromosomal region of shigella dysenteriae is well established that plasmids are involved in the expression of lipopolysaccharide in certain species of shigella. in shigella sonnei, both the biosynthesis of oligosaccharide side chains (o antigen), and cell invasiveness are controlled exclusively by a 120 megadalton (mda) plasmid. in shigella dysenteriae 1, a 10 kilobase (kb) plasmid is required for o-antigen production. shigella dysenteriae 1 strains devoid of this plasmid lose the ability to synthesize o antigen. interestingly, this ...19882454151
epitope mapping of hla-b27 and hla-b7 antigens by using intradomain study the hla-b7 and hla-b27 antigenic determinants, hybrid genes between these two alleles were constructed by in vivo recombination in escherichia coli. after transfection of these genes into p815 (high transfection efficiency recipient) murine cells, the bindings of bw6, hla-b7, and hla-b27 allele-specific mab were studied, as well as that of human anti-hla-b7 and anti-hla-b27 monospecific alloantisera. most of the hla-b7 antigenic determinants were assigned to the first external domain of ...19882459214
somatic antigens of shigella: structure of the o-specific polysaccharide chain of the shigella dysenteriae type 7 lipopolysaccharide.4-(n-acetylglycyl)amino-4,6-dideoxy-d-glucose has been identified as a component of the shigella dysenteriae type 7 o-specific polysaccharide, in addition to the previously reported 2-acetamido-2-deoxy-d-glucose and 2-acetamido-2-deoxy-d-galacturonic acid. on the basis of selective cleavage with anhydrous hydrogen fluoride and analysis by 1h- and 13c-n.m.r. spectroscopy and f.a.b.-mass spectrometry, it was concluded that the tetrasaccharide repeating-unit of the polysaccharide has the following ...19882463086
purification and characterization of a phage-encoded cytotoxin from an escherichia coli o111 strain associated with hemolytic-uremic syndrome.cytotoxin production by escherichia coli o111:h-strain hus-2 (hamburg) is associated with a temperate toxin-converting bacteriophage (tcp-111). e. coli laboratory strain c600 transduced and subsequently lysed by the phage produced and liberated large amounts of cytotoxin (ct111) which was purified by sequential chromatography. when compared with published procedures for toxin release from viable cells, lysis of the c600 culture by the phage was most effective. by sds-page ct111 as shiga toxin fr ...19882464885
enteropathogens isolated from children with gastro-enteritis at ga-rankuwa hospital, south africa.a prospective 3-year study for enteric pathogens associated with diarrhoea in children was undertaken at ga-rankuwa hospital, south africa. rotavirus was the most commonly isolated pathogen (24%), showing a marked seasonal distribution, with an autumn peak in activity. enterotoxigenic and enteropathogenic escherichia coli were frequently identified, and salmonella, shigella and campylobacter were also isolated. cryptosporidium and giardia lamblia were the most frequently seen parasites. rotaviru ...19882467616
cloning of the rfb gene region of shigella dysenteriae 1 and construction of an rfb-rfp gene cassette for the development of lipopolysaccharide-based live anti-dysentery vaccines.recent studies have shown that determinants for the production of o antigen lipopolysaccharide in shigella dysenteriae 1 are distributed over two distinct genetic elements, the chromosome and a 9 kb plasmid designated phw400. in this communication, we describe the cloning of all determinants necessary for s. dysenteriae 1 o antigen production in e. coli k-12 and their combination in a single plasmid. an rp4::minimu r-prime plasmid, r-prime 40, containing the his-rfb (histidine biosynthesis-lipop ...19862469931
genetic and biochemical analysis of shigella dysenteriae 1 o antigen polysaccharide biosynthesis in escherichia coli k-12: 9 kb plasmid of s. dysenteriae 1 determines addition of a galactose residue to the lipopolysaccharide core.production of the somatic antigen, o-specific polysaccharide of shigella dysenteriae 1 is determined by the chromosomal rfb gene cluster and the rfp gene located on the 9 kb plasmid phw400 carried by this organism. when transferred to escherichia coli k-12, which produces lipopolysaccharide consisting only of core oligosaccharide linked to lipid a, rfp gene-containing plasmids caused modification of the core oligosaccharide leading to the appearance of core molecules with new electrophoretic mob ...19862469932
genetic and biochemical analysis of shigella dysenteriae 1 o antigen polysaccharide biosynthesis in escherichia coli k-12: structure and functions of the rfb gene cluster.the genetic organization and functions of the shigella dysenteriae 1 rfb gene cluster, which specifies the somatic o antigen in this organism, have been studied in escherichia coli k-12 by insertion and deletion mutagenesis of pss9, a pbr322 hybrid containing the shigella rfb genes. on the basis of the sensitivity/resistance to rough-specific bacteriophage t3 of e. coli k-12 derivatives containing mutant pss9 plasmids, of the banding patterns and immunoreactivity of lps isolated from such deriva ...19862469933
production and characterisation of monoclonal antibodies to verotoxins 1 and 2 from escherichia coli of serotype o 157:h7.fourteen hybridoma cell lines were isolated that produced monoclonal antibodies (mabs) to purified verotoxins 1 and 2 (vt1, vt2) of escherichia coli of serotype o157:h7. of these mabs, eight were obtained by immunisation of balb/c mice with purified vt1, and six were obtained from balb/c mice immunised with purified vt2. with the exception of mab 1c5, with a heavy chain of igg2b class, antibodies produced from mice immunised with heat-treated toxin were of igm class. mabs produced from mice immu ...19892479749
effect of detoxification processes on the interferon-inducing activity of bacterial endotoxins.the interferon (ifn)-inducing activity of detoxified lipopolysaccharide (lps) was tested in rabbits treated with lps preparation derived from escherichia coli, salmonella typhi, salmonella enteritidis and shigella dysenteriae serovar 1. of the detoxification procedures used, alkaline hydrolysis, hydroxylaminolysis, formalization, treatment with sodium deoxycholate and the radiodetoxification (fast or slow) methods had no appreciable effects on the ifn-inducing potential of lps. in contrast, acet ...19892484274
studies on shiga-like toxin produced by enterohemorrhagic escherichia coli: purification and characterization of the toxin and development of methods for identifying the toxin.a simple purification method using deae cellulose column chromatography and immunoaffinity column chromatography was developed for purifying shiga-like toxin produced by escherichia coli o157:h7. about 0.75 mg of purified toxin was obtained from 5 liters of culture (62% recovery). the purified toxin was demonstrated to be immunologically, biologically and structurally indistinguishable from shiga toxin. a sandwich enzyme-linked immunosorbent assay (elisa) was developed for detection of shiga-lik ...19892485395
[imported myiasis: analysis of 5 cases].five cases of furuncular myiasis imported by spanish travelers from tropical countries are reported. after reviewing the cycle of the infecting organism and the characteristics of the human disease, a table with the clinical and epidemiological data of our patients is presented. the relevance of an adequate clinical and geographical anamnesis in these patients is discussed. finally, the effectiveness of a simple, nonaggressive treatment is reported, which permits the patient to verify by himself ...19892490857
nonrandom rearrangement of chromosome 14 at band q32.33 in human lymphoid malignancies with mature b-cell phenotype.chromosomes were studied in 61 patients with differentiated b-cell malignancies including 21 with non-hodgkin's lymphoma (nhl), three with hairy cell leukemia (hcl), eight with waldenström's macroglobulinemia (wm), and 29 with plasma cell disorder. chromosomally abnormal clones were identified in 35 of 61 patients studied: all with nhl, all with hcl, three of eight with wm, and eight of 29 with plasma cell disorder. the most recurrent chromosomal abnormality, observed in 26 of the 35 patients wh ...19892492904
four new provisional serovars of shigella.four bacterial strains are described that possess the biochemical characteristics of shigella species but do not belong to any of the established shigella serovars or to any previously described provisional serovar. one strain fermented mannitol, and it is proposed that this be the type strain for a new provisional serovar of shigella boydii. the remaining strains did not ferment mannitol and belonged to three different serovars. these strains are proposed as type strains for three new provision ...19892501349
hemagglutinating properties of shigella dysenteriae type 1 and other shigella species.strains of shigella dysenteriae type 1 cultured in casamino acids-yeast extract broth medium in the presence of 1 mm calcium chloride at 37 degrees c for 22 h induced hemagglutination of erythrocytes that was inhibited by n-acetylneuraminic acid, n-acetylneuramin-lactose, and alpha 1-glycoprotein. the hemagglutination was heat labile, and the absence of cell-surface appendages suggested a nonfimbrial adhesin(s). under the same conditions, strains of shigella flexneri (types 1a, 1b, 2a, and 2b) s ...19892503449
[increased efficiency in the disinfection of sewage by lactic acid bacteria].the antimicrobic properties have been studied in 30 strains of lactobacilli. as a result a strain, the strongest antagonist relative to choleric vibrios and other enteropathogenic microorganisms, is selected. lactobacilli are found to retain their viability and biological activity in the activated sludge during the whole period of observation (6 months). biological disinfection of sewage is shown possible to be intensified using the activated sludge inoculated by the culture of the selected lact ...19892514340
[in vitro susceptibility of campylobacter jejuni and campylobacter coli to quinolone antibiotics].in this study, in vitro susceptibilities of 24 campylobacter strains isolated from fecal samples were tested for quinolone antibiotics. 13 of the strains were identified as c. jejuni and 11 of them were c. coli. antibiotics which were included in this study were ciprofloxacin, ofloxacin, pefloxacin and fleroxacin. antibiotic susceptibility tests were performed on mueller-hinton agar (supplemented with 5% sheep blood) using the agar dilution method. results showed that quinolone antibiotics are v ...19892518646
identification of shiga-like toxin in escherichia coli strains, etiological agents of diarrheal disease.shiga-like toxin presence, in 20 e. coli strains, etiological agents of diarrheal diseases, is studied by preparing extracts at +4 degrees c, in the presence of chloroform and by i.v. inoculation in mice. in 4 out of 20 strains, shiga-like toxin in high titres was identified. most of the strains presented an inconstant and variable production of shiga-like toxin in comparison with shigella dysenteriae type 1 (shiga) reference strain. the authors also confirm the existence of shiga-like toxin und ...19892520669
[the dependence of hemoglobin and iron reserve indices on habitat conditions (sampling research in osh province, the kirghiz ssr)].sampling investigation of female population (896 subjects) was conducted in five regions with opposite environmental conditions. a relatively low incidence of iron deficiency anemia and high incidence of exhausted iron reserves in the women living in the high mountains indicates the participation of the adaptive-compensatory mechanisms in the development of iron-deficiency. a high rate of iron deficiency incidence in the regions of intensive tobacco growing and association of iron-deficiency ane ...19892533125
effects of the nmda receptor antagonist mk-801 against amygdaloid-kindled seizures in the rat.the effects of acute and subchronic administration of the noncompetitive nmda receptor antagonist mk-801 on the duration and severity of amygdaloid-kindled seizures in rats were determined to evaluate its anticonvulsant activity. both the highest acute (1000 micrograms/kg) and subchronic regimens (2 x 300 micrograms/kg, 7 days) produced significant reductions in the seizure stage and afterdischarge duration. although ataxia may have affected the seizure stage, mk-801 attenuated the primary after ...19892536332
multiple cooperative interactions constrain bpv-1 e2 dependent activation of transcription.transcription directed by the bpv-1 long control region (lcr) is conditional upon activation by the virally encoded e2 protein. within the 1.0 kb lcr there are five separate regions, a to e, that contain e2 responsive enhancers. the smallest functional region, a, is only 38 bp and contains two copies of the consensus sequence acc(n)6ggt that is known to function as an e2 binding site in vitro. we show that a pair of these constitutes a minimal functional e2 responsive enhancer element but that t ...19892542891
dual function of a nuclear factor i binding site in mmtv transcription regulation.using linker-scanning mutagenesis we had previously identified four elements within the mmtv ltr which are necessary for transcriptional stimulation by glucocorticoid hormones. two of them overlapped with regions to which the glucocorticoid receptor binds in vitro. the third element contained a nf-i binding site, and the fourth the tata box. here we show that mutations that abolish in vitro binding of nf-i had a negative effect also on the basal activity of the mmtv promoter of ltr-containing pl ...19892542892
influence of diethyldithiocarbamate on nickel-induced hepatic metallothionein in rats.the influence of sodium diethyldithiocarbamate (ddc) on 63nickel chloride-induced metallothionein (mt) and alterations in essential metal levels in the liver of rats was investigated. the induction of mt, zn and cu levels of the hepatic cytosolic "heat stable fraction" (hsf) by ddc increased with time up to 24 hr. although mt, zn and cu were significantly greater at 17 hr than those at 6.5 hr after 63ni administration, the ni level decreased. the treatment with ddc at 6 hr, but not at 10 min, pr ...19892548306
phosphate regulon in members of the family enterobacteriaceae: comparison of the phob-phor operons of escherichia coli, shigella dysenteriae, and klebsiella pneumoniae.the structure and function of the phob and phor genes of shigella dysenteriae strains and klebsiella pneumoniae, which are involved in regulation of the phosphate regulon, were analyzed. complementation tests among the genes of escherichia coli, s. dysenteriae strains, and k. pneumoniae for production of alkaline phosphatase indicate that s. dysenteriae serotype 2 and serotype 3 strains and k. pneumoniae are phoa+ phob+ phor+ but s. dysenteriae sh and serotype 1 strains are phoa phob+ phor. nucl ...19892556368
characterization of the rela1 mutation and a comparison of rela1 with new rela null alleles in escherichia coli.the most widely studied "relaxed" mutant of the rela locus, the rela1 allele, is shown here to consist of an is2 insertion between the 85th and 86th codons of the otherwise wild-type rela structural gene, which normally encodes a 743-amino acid (84 kda) protein. the rela protein is a ribosome-dependent atp:gtp (gdp) pyrophosphoryltransferase that is activated during the stringent response to amino acid starvation and thereby occasions the accumulation of guanosine 3',5'-bispyrophosphate (ppgpp). ...19892556396
[acute maternal anterior poliomyelitis in a non-endemic zone].the authors report the case of a 26 year old woman with acute anterior poliomyelitis contracted during the vaccination of her baby. despite having been herself vaccinated in infancy she was not protected against the poliovirus. the clinical interest of this uncommon case is a severe paralytic state with definitive paraplegia. the authors suggest serologic testing of patients born before 1967 especially if they are at risk of encountering the virus.19892561040
endocytosis from coated pits of shiga toxin: a glycolipid-binding protein from shigella dysenteriae 1.evidence is presented that endocytosis is involved in the transport to the cytosol of the cytotoxin from shigella dysenteriae 1, shiga toxin, which acts by removal of a single adenine residue in 28-s ribosomal rna. inhibition of endocytosis by atp depletion of the cells prevented toxin uptake. exposure of hela s3 and vero cells to toxin at low extracellular ph, where translocation to the cytosol, but not endocytosis is inhibited, allowed the toxin to accumulate in a compartment where it was prot ...19892564398
shigella dysenteriae type 1 infections in us travellers to mexico, 1988, the number of shigella dysenteriae type 1 (sd1) infections reported in the usa increased five-fold over the annual mean from the previous decade. 44 (94%) of 47 interviewed patients reported recent travel to mexico; 33 (75%) of these had been tourists to the yucatan peninsula. 27 patients who had travelled to mexico were admitted to hospital, of whom 2 had a haemolytic uraemic syndrome; none died. the antimicrobial resistance pattern and plasmid profile of the yucatan strain were simila ...19892570242
expression and desensitisation of a2 purinoceptors on cultured bovine aortic endothelial cells.purine nucleotides and their metabolites are important mediators of vascular tone. adenosine promotes relaxation of vascular smooth muscle, acting on the a2 subclass of purinoceptors. there is some evidence that these receptors are also present on vascular endothelial cells. we have therefore examined cultured aortic endothelial cells for adenosine (a2) sensitivity. bovine aortic endothelial cells (ag4762) were obtained from the institute of aging cell repository (usa), and cultured in monolayer ...19892590913
causes of death and the histopathologic findings in fatal shigellosis.thirty-seven children (median age, 2 years) with shigellosis in bangladesh were subjected to postmortem examination to determine causes of death and the spectrum of intestinal histopathology. infecting species were: shigella dysenteriae 1, 7 cases; s. dysenteriae 2, 2 cases; shigella flexneri, 23 cases; shigella boydii, 4 cases; and mixed infection with shigella boydii and shigella sonnei, 1 case. complicating conditions detected before death included malnutrition in 25 cases, pneumonia in 11 ca ...19892594452
[risk factors for condylomata. a case control study].the present study involves 214 patients whose cervical smear showed signs of human papilloma virus infection (hpv), matched with 1042 controls. we demonstrate increasing odds ratio with the total number of sexual partners since first sexual intercourse (p less than 0.0001). moreover the cases have more often changed partners in the year preceding the diagnosis (odds ratio 2.6 p less than 0.0001). their male partners more often have occupations that expose them to "extra-conjugal adventures" (p = ...19892600372
cockroaches (periplaneta americana) as carriers of agents of bacterial diarrhoea in accra, ghana.bodies and intestinal contents of 208 cockroaches (periplaneta americana), collected from kitchens in accra and some surrounding villages were cultured for enteric bacterial pathogens. six of them harboured three different serogroups of salmonella, one had shigella dysenteriae, 64 had coliforms, 13 had proteus species, two had pseudomonas species and the rest (122) carried none of the bacterial species mentioned above. the presence of salmonella species shigella dysenteriae and coliforms in thes ...19892611875
histotypic differentiation of neonatal mouse retina in organ culture.retinae from neonatal mice were explanted in toto, with or without the retinal pigment epithelium (rpe) and adjoining mesenchymal cells, and maintained in organ culture for up to 3 weeks. the explants remained flat, rosette formation was minimal and histogenetic changes followed in the normal sequence. after 11, 14 and 21 days in vitro the three cellular layers--the outer nuclear layer including well differentiated rod and cone perikarya, the inner nuclear layer and the ganglion cell layer--with ...19892612197
histotypic differentiation of neonatal mouse retina in organ culture.retinae from neonatal mice were explanted in toto, with or without the retinal pigment epithelium (rpe) and adjoining mesenchymal cells, and maintained in organ culture for up to 3 weeks. the explants remained flat, rosette formation was minimal and histogenetic changes followed in the normal sequence. after 11, 14 and 21 days in vitro the three cellular layers--the outer nuclear layer including well differentiated rod and cone perikarya, the inner nuclear layer and the ganglion cell layer--with ...19892612197
indomethacin blocks the anorexic action of has been reported recently that the central nervous system actions of interleukin-1 are mediated by the prostaglandin system in the brain. the present study was therefore performed in order to examine the hypothesis that indomethacin, an inhibitor of prostaglandin biosynthesis, might alleviate the interleukin-1-induced suppression of food intake in rats. the i.p. injection of interleukin-1 (2 micrograms/rat) resulted in a significant decrease in food intake. the pre-injection of indomethacin ...19892620696
indomethacin blocks the anorexic action of has been reported recently that the central nervous system actions of interleukin-1 are mediated by the prostaglandin system in the brain. the present study was therefore performed in order to examine the hypothesis that indomethacin, an inhibitor of prostaglandin biosynthesis, might alleviate the interleukin-1-induced suppression of food intake in rats. the i.p. injection of interleukin-1 (2 micrograms/rat) resulted in a significant decrease in food intake. the pre-injection of indomethacin ...19892620696
isolation of inhibitors of adenylate cyclase from dan-shen, the root of salvia miltiorrhiza.the effect of dan-shen extract, the root of salvia miltiorrhiza, on adenylate cyclase was investigated in both rat brain and rat erythrocytes. the etoac fraction of the meoh extract was proved to have significant inhibitory activity. potent inhibitory principles in the etoac fraction were isolated and identified as 4 polyphenolic acids, rosemarinic acid, lithospermic acid, and their methyl ester derivatives.19892630095
[detection of streptococci from various serological groups in animals].during the period from 1985 to 1988 we determined 228 strains of streptococci isolated from samples of various sorts of biomaterials, mainly animals. from this set of streptococci we classified 207 strains into serological groups according to the lancefield classification and about 30% strains into species by means of serological and biochemical methods. most of the strains were allocated to group c (37.28%) and group q (17.39%). 89 streptococci strains originated from pigs, 40 strains from hors ...19892631378
[serological diagnosis of campylobacter jejuni infections].antibody level to campylobacter in 28 sera of patients of whom campylobacter infection was confirmed by germ isolation from feces was tested. the investigation was performed using passive haemagglutination technique and as antigens heated and acid glycine extraction prepared from homologous and reference strains. for the method used the heated antigen proved to be superior. out of 28 tested patients of whom 92.8% were children, 8 sera were positive, 9 doubtful and 9, derived mainly from neonates ...19892640683
detection of enterotoxigenic escherichia coli after polymerase chain reaction amplification with a thermostable dna polymerase.the direct identification of enterotoxigenic escherichia coli from clinical specimens was examined by using the polymerase chain reaction (pcr) for amplifying the heat-labile toxin (lt) gene. two synthetic primers, each of which was 20 bases in length, were used with the thermostable dna polymerase from thermus aquaticus to amplify the lt gene. the amplified pcr products were detected by either gel electrophoresis or hybridization to a 24-base synthetic oligonucleotide probe conjugated to alkali ...19892644292
introduction and spread of multi-resistant shigella dysenteriae i in thailand.outbreaks of shigella dysenteriae i occurred in northeastern thailand in the fall of 1986 and again in the spring and fall of 1987 for the first time in over 20 years. the epidemic strain of s. dysenteriae i was resistant to tetracycline, streptomycin, chloramphenicol, and trimethoprim-sulfamethoxazole, but susceptible to ampicillin. trimethoprim resistance was chromosomally encoded by type i dihydrofolate reductase. in ubon province, where 10,000 cases of dysentery were reported, there were 3-5 ...19892644859
plasmid dna analysis by agarose gel electrophoresis on an epidemic-associated strain of trimethoprim resistant shiga's bacillus from gimira wereda (keffa administrative region, southwest ethiopia).a combination of genetic mating experiments and plasmid dna analysis by gel electrophoresis was carried out on an epidemic-associated shiga's bacillus with resistance type acssuttp, isolated in 1983 from gimira wereda, keffa administrative region, south west ethiopia. the donor strain contained 9 plasmid species. their sizes in megadaltons (mdal) were: 120, 40, 35, 12.5, 6.0, 5.1, 4.3, 2.5 and 1.7. analysis of escherichia coli k12 transconjugants revealed that the 40, 35, and 4.3 mdal plasmids c ...19892646117
renin: endocrine, paracrine, or part-paracrine control of blood pressure? 19892650710
pathogenesis of shigella diarrhea. xiv. analysis of shiga toxin receptors on cloned hela cells.binding kinetics of shiga toxin to hela ccl-2 cells and to cell lines cloned by limiting dilutions were determined. lines with a wide range of sensitivity to shiga toxin were obtained. binding data, analyzed by a computer-based scatchard model program, revealed two classes of binding sites, one of low affinity and high capacity and one of high affinity and low capacity. the number of high affinity, but not low affinity, sites present on the clones correlated with their sensitivity to toxin. tuni ...19892651533
interaction of shigella toxin with globotriaosyl ceramide receptor-containing membranes: a fluorescence study.the interaction of the b-subunit of shigella toxin with a globotriaosyl ceramide receptor incorporated into phosphatidylcholine vesicles was studied by fluorescence spectroscopy. from the position of the maximum in the emission spectrum and the accessibility to acrylamide quenching, it is concluded that a single tryptophan of a free b-chain is located in a highly polar environment, most likely on the surface of the folded polypeptide chain. binding of b-subunits to the membrane-associated globot ...19892653314
malignant hyperpyrexia. 19892653537
unusual nucleotide arrangement with repeated sequences in the escherichia coli k-12 chromosome.between 59 and 60 min on the escherichia coli genetic map, there is a highly conserved sequence of 29 base pairs, containing an inverted repeat of seven base pairs that appears 14 times, 32 or 33 base pairs apart, downstream of the iap gene coding region. about 24 kilobase pairs downstream of the 14 repeats, a similar 29-base-pair sequence with a spacing of 32 base pairs appears seven times. nucleotide sequences hybridizing with the 29-base-pair fragment were also detected in shigella dysenteria ...19892656660
inoculum size in shigellosis and implications for expected mode of transmission. 19892656880
[survey on overseas traveller's diarrhea at narita airport quarantine station--the species of bacteria isolated and the suspected countries for infection]. 19892657132
[clinical features of overseas travellers' infectious enteritis admitted in the hospitals for infectious diseases]. 19892657133
secretory immunoglobulin a response to shiga toxin in rabbits: kinetics of the initial mucosal immune response and inhibition of toxicity in vitro and in vivo.although the role of shiga toxin in dysentery is unknown, the toxin is cytotoxic to hela cells, causes fluid secretion in rabbit intestine, and is lethal to rabbits and mice when injected parenterally. in the present study, rabbits received three weekly doses of shiga toxin directly into chronically isolated ileal loops. within a week, secretions from these loops contained immunoglobulin a (iga) anti-shiga toxin. the titer of iga anti-shiga toxin increased after weekly doses 2 and 3. little igg ...19892659525
epidemic shigellosis due to shigella dysenteriae type 1 in south asia. 19892661420
quantitation of the rabbit intestinal glycolipid receptor for shiga toxin. further evidence for the developmental regulation of globotriaosylceramide in microvillus membranes.shiga toxin, produced by shigella dysenteriae 1, causes enterotoxic, cytotoxic, and neurotoxic effects, which may be mediated by a glycolipid receptor, globotriaosylceramide, gb3. to study the relationship of this receptor and toxin effects, globotriaosylceramide was quantitated and further characterized in rabbit small intestinal microvillus membranes at various ages. glycolipids were extracted from rabbit microvillus membranes, purified on unisil columns, and quantitated by high-performance li ...19892663611
congo red-mediated regulation of levels of shigella flexneri 2a membrane proteins.the ability of shigella spp. to bind congo red from agar medium is generally correlated with their virulence properties. we used a metabolically active culture of shigella flexneri 2a to determine the effect of congo red on its membrane protein profiles. virulent s. flexneri grown in the presence of congo red at 37 degrees c showed increased levels of three proteins with mrs of 43,000, 58,000, and 63,000 (43k, 58k, and 63k proteins) in the sarkosyl-soluble membrane fractions. the observed phenom ...19892663721
rapid method to detect shiga toxin and shiga-like toxin i based on binding to globotriosyl ceramide (gb3), their natural receptor.shiga toxin and the closely related shiga-like toxins produced by escherichia coli represent a group of very similar cytotoxins that may play an important role in diarrheal disease and hemolytic uremic syndrome. these toxins have the same biologic activities and according to recent studies also share the same binding receptor, globotriosyl ceramide (gb3). they are currently detected, on the basis of their ability to damage several cell lines, by using expensive and tedious assays that require fa ...19892666433
use of monoclonal antibodies to type shigella flexneri in bangladesh.a panel of 10 mouse and rat monoclonal antibodies specific for different type- and group-specific o-antigenic determinants of shigella flexneri lipopolysaccharide was used to serotype 240 isolates of s. flexneri from bangladesh. three immunoglobulin m antibodies were used in a direct slide agglutination test; seven immunoglobulin g antibodies were absorbed to staphylococcus aureus and used in a coagglutination assay. all but 13 of the isolates could be serotyped by using the monclonal antibodies ...19892666435
cryptococcus neoformans in the seminal fluid of an aids patient. a contribution to the clinical course of a 33-year-old hiv-positive homosexual male suffering from unexplained headache, cryptococcosis was diagnosed in a progressive secondary stage. after treatment with the standard combination therapy of amphotericin b + flucytosine for 34 d, the patient was clinically symptom-free and discharged, upon his own request, from the hospital. he remained under ambulatory mycological control. after an interval of 65 d during which the urine had been free from cryptococcus neoformans (cr.n.), the fungus ...19892666852
purification, crystallization, and preliminary x-ray diffraction studies of the flavoenzyme mercuric ion reductase from bacillus sp. strain rc607.the flavoenzyme mercuric ion reductase from bacillus sp. strain rc607 was purified by dye-ligand affinity chromatography. the protein was crystallized from solutions of high ionic strength, and one of the two crystal forms obtained has proven suitable for x-ray diffraction studies. preliminary analysis showed that these crystals belong to the tetragonal space group 1422. the unit cell dimensions are a = b = 180.7 a; c = 127.9 a. the diffraction pattern extends to better than 3 a resolution. crys ...19892668287
hemolytic uremic syndrome and diarrhea in argentine children: the role of shiga-like toxins.shiga-like toxin-producing escherichia coli have been associated with hemorrhagic colitis and the hemolytic uremic syndrome (hus). because argentina has the highest reported frequency of hus in the world, argentine children were prospectively studied during the hus seasons for evidence of shiga-like toxin-related diseases. on the basis of serology, fecal cytotoxin neutralization, stool cultures, and dna hybridization of colony lysates, most children with hus had evidence of infection with shiga- ...19892668430
[bacillary dysentery--1987]. 19892669032
antibiotics in the management of shigellosis in children: what role for the quinolones?in the last 20 years, epidemic bacillary dysentery due to shigella dysenteriae type 1 has become an important cause of serious morbidity and death in children less than 5 years of age in a number of developing countries; in many instances the infecting strains have been resistant to many or all of the usually recommended antibiotics. moreover, an increasing proportion of shigella strains of other serotypes isolated in all parts of the world are now resistant to the most commonly used antibiotics ...19892672246
mechanisms of tumor induction by human retroviruses.oncogenesis can be induced by chronic and acute rna tumor viruses through a promoter/enhancer insertion mechanism and through a transforming protein coded by a viral oncogene (v-onc), respectively. a hypothetical trans-activating mechanism is invoked by retroviruses with trans-activating regulatory proteins. so far, in humans only htlv-i has been firmly linked to a malignancy. the same virus is also implicated in slowly progressing neurological disorders. except for transformation by viral oncog ...19892673254
clinical & bacteriological profiles of shigellosis in calcutta before & after an epidemic (1984-87).patients below 5 yr of age, hospitalised for shigellosis over a period of four years (1984-87), were studied. during the epidemic of bacillary dysentery (1984) isolation of different shigella spp. as well as shigella dysenteriae type 1 was high. decreased isolation of sh. dysenteriae type 1 and increased isolation of sh. flexneri was observed during post-epidemic years (1985-87). isolation of different shigella spp. was always above 25 per cent from patients with dysentery and greater than 7 per ...19892674001
lymphocyte homing.the phenomenon of "homing" is discussed with respect to patterns of lymphocyte circulation and the molecules on the surface of both endothelium and lymphocytes that mediate this process. in addition, the data are analysed in the context of a model for lymphocyte homing.19892675225
isolation and characterization of functional shiga toxin subunits and renatured holotoxin.shiga toxin is a protein toxin produced by shigella dysenteriae type i strains. in this report we present a procedure for the separation of functionally intact toxin a and b chains and for their reconstitution to form biologically active molecules. in agreement with the findings of others, the isolated a chain was shown to be a potent in vitro inhibitor of eukaryotic protein synthesis. the isolated b chain bound to hela cells and competitively inhibited the binding and cytotoxic activity of holo ...19892677606
normal catch-up growth in rats severely food-restricted prior to lesions of the dorsomedial hypothalamic nucleus: the first 48 hours.following a brief period of ad lib (al) feeding, 45-day-old male sprague-dawley rats were either fed al or food-restricted (rest) for 21 days to 50% of the intake of the al rats. at this time, some al and some rest rats received electrolytic lesions in the dorsomedial hypothalamic nuclei (dmnl), whereas other al and rest rats were sham-operated (con). following this, all rats were refed (ref) al and killed two days later. at this time, dmnl-rest + ref and dmnl-al weighed as much as con-rest + re ...19892678164
thymotaxin, a chemotactic protein, is identical to beta 2-microglobulin.thymotaxin, an 11-kilodalton protein chemotactic for rat bone marrow hematopoietic precursors, was purified from media conditioned by a rat thymic epithelial cell line. the nh2-terminal sequence of thymotaxin was identical to that of rat beta 2-microglobulin (beta 2m). antibodies to beta 2m removed thymotaxin activity from the fraction containing the 11-kilodalton protein. chemotactic activity was observed with rat plasma beta 2m, human beta 2m, and mouse recombinant beta 2m, further supporting ...19892683083
[cellular lectin binding sites in the human retinal pigment epithelium and photoreceptors--method of lectin histochemistry and results with peroxidase marked lectins in paraffin sections].lectins are sugar-binding proteins or glycoproteins which bind to specifically complementary sugar residues found in cell membranes and the cytoplasm. lectin-binding sites are determined by histochemical methods. cellular lectin-binding sites change with morphological and functional alterations of the cell, and the determination of lectin receptors can be used to identify specific cell types in histological sections. lectin-binding sites of the human retinal pigment epithelium (rpe) and photorec ...19892684825
monoclonal antibodies against the surface antigens of shigella flexneri serotype 1b and shigella dysenteriae serotype 1.monoclonal antibodies against the surface antigens of shigella flexneri 1b and s. dysenteriae 1 were prepared. the specificities of the antibodies were evaluated by enzyme-linked immunosorbent assay (elisa), and quantitative agglutination using microtiter plate. monoclonal antibodies against s. flexneri 1b, designated sf2b2 and sf2g4, belonged to igg2a and igg1 subclass, respectively. the former was specific for s. flexneri 1b, whereas the latter was reactive not only to s. flexneri 1b, but also ...19892687648
assay for sialidase using erythrocytes and peroxidase-labeled peanut lectin.a rapid and sensitive sialidase assay method based on peroxidase-labeled peanut lectin (pna) binding to desialylated erythrocyte is described. formalinized sheep erythrocytes were used both as a stable substrate for sialidase and as a target for the lectin. in the case of sialidases from vibrio cholerae and arthrobacter ureafaciens, a linear relationship was observed between the amount of peroxidase-labeled pna bound to erythrocytes and the enzyme amount. binding of the lectin to sialidase-treat ...19892688936
purification of shiga toxin by alpha-d-galactose-(1----4)-beta-d-galactose-(1----4)-beta-d-glucose-(1- ---) receptor ligand-based chromatography.a simple and rapid method for shiga toxin purification based on specific binding to the gal alpha 1----4gal beta 1----4glc globotrioside trisaccharide covalently linked to polyacryl/polyvinyl (fractogel) has been developed. a cell-free sonicate-filtrate of shigella dysenteriae type 1, strain 114sd was passed over the globotrioside-fractogel column, and bound toxin eluted with 6 m guanidine-hcl. a yield of 36 mg pure toxin/1 sonicate-filtrate was obtained, i.e. a one step 1224-fold purification. ...19892689221
nutritional anestrus in beef cows: concentrations of glucose and nonesterified fatty acids in plasma and insulin in serum.twenty-two nonlactating hereford cows exhibiting normal estrous cycles were fed either maintenance (m) or restricted (r) diets until most of the r cows became anestrus; r cows then were fed 160% of the m diet until estrous cycles resumed. concentrations of progesterone, glucose, insulin and nonesterified fatty acids (nefa) were determined in weekly blood samples. blood also was collected frequently, before and after i.v. infusion of 300 ml of a 40% glucose solution, to evaluate responses in bloo ...19892689418
production of vero cytotoxin by escherichia coli and shiga toxin by shigella dysenteriae 1 as related to the growth medium and availability of iron.six strains of escherichia coli producing vero cytotoxin (vtec) and six strains of shigella dysenteriae 1 were examined for the production of extra- and intracellular vero cytotoxin (vt) and shiga toxin respectively, in relation to the growth medium and availability of iron. vtec secreted less extracellular vt1 or vt2 when grown in trypticase soy broth (tsb) containing the iron chelator desferal, as compared to bacteria cultured in iron replete tsb. growth in tsb containing desferal resulted in ...19892692581
falciparum malaria--present day problems. an experience with 425 cases.clinical details and present day problems encountered in 425 cases of falciparum malaria (pf) are reported. 10.11% had taken chloroquine prior to reporting to us. parasitic count done in 23.05% cases lacked correlation with severity of disease. pattern of fever varied markedly but 5.4% were afebrile throughout and presented only with bodyache and malaise. apyrexial spell was noted in 5.64%. 28.70% had typical facial looks of anaemia and sallow complexion. cerebral symptoms were noted in 3.05%. o ...19892693436
[shigellosis in the ussr: the etiological role of shigella dysenteriae].the etiological role of s. dysenteriae in shigella infections at different territories of the ussr in 1983-1987 is analyzed. the study shows that s. dysenteriae pertain to territories with unfavorable water supply of the population. at some of these territories, in particular the uzbek ssr, grigor'ev-shiga dysentery seems to gain ground and the restoration of the area of its spread occurs. in recent years the penetration of grigor'ev-shiga dysentery from abroad became more frequent in the presen ...19892694693
[drug resistance of the causative agent of grigo'rev-shiga dysentery (shigella dysenteriae 1)isolated in the ussr].forty strains of s. dysenteriae 1 isolated in the ussr within 1986-1988 were tested for their resistance to 11 antibacterial drugs. it was shown that 92.5-97.5 per cent of the isolates were resistant to chloramphenicol (cm) and tetracycline (tc), 22.5 per cent to streptomycin (sm), 17.5 per cent to nalidixic acid (nal) and 10 per cent to ampicillin (ap) and polymyxin (pm). resistance to cm tc (51.4 per cent) and cm tc nal (13.5 per cent) represented the predominating phenotype. 35 per cent of th ...19892694989
characterization and autoprocessing of precursor and mature forms of human immunodeficiency virus type 1 (hiv 1) protease purified from escherichia coli.a recombinant plasmid encompassing the human immunodeficiency virus type 1 (hiv 1) protease coding sequence and flanking regions (ala-13 to gly-185 of the pol open reading frame) has been expressed in two distinct strains of escherichia coli, ar58 and ar68. in the first strain, ar58, the primary translation product, a 25 kilodalton (kda) precursor protein, is short-lived and rapidly processes itself to the 11 kda mature protease in vivo. in the second strain, ar68, the 25 kda species is only par ...19892695927
[the etiological structure of shigellosis in the ussr in recent years].the characterization of etiological structure of shigella infection in the whole of the ussr, in individual union republics and at a number of other administrative territories of the ussr in recent years is presented. s. flexneri has been shown to prevail at the territories with unsatisfactory water supply of the population, and s. sonnei prevails at the territories with good water supply. at the former territories s. dysenteriae and s. boydii retain their etiological importance, while at the la ...19892698030
[development of antibiotic resistance of type 1 shigella dysenteriae strains (shiga bacillus) isolated in tananarive on the east coast of madagascar].from november 1988 to march 1989, 804 malagasy children stools were studied and 37 shigella strains isolated. 5 shigella dysenteriae type 1 from malagasy east coast (mananjary), presented a multiply resistance to ampicillin, carbenicillin, streptomycin, chloramphenicol, tetracycline, sulphonamides and trimethoprim. this last resistance has recently appeared in this area.19892699224
thromboxane synthase activity and platelet function after furegrelate administration in man.furegrelate sodium (u-63,557a), a pyridine-derivative thromboxane synthase inhibitor, was administered orally in single doses of 200 to 1600 mg to normal male subjects. furegrelate produced a dose-related inhibition of thromboxane synthesis for 8-12 hours when measured either ex vivo from platelet-rich plasma (prp) or in vivo from urine. in general, the extent of thromboxane synthesis inhibition was greater in prp than in urine. furegrelate significantly inhibited platelet aggregation, but the e ...19892708549
immunoblotting analysis of the reaction of wildebeest, sheep and cattle sera with the structural antigens of alcelaphine herpesvirus-1 (malignant catarrhal fever virus).malignant catarrhal fever (mcf) is a disease of cattle and some other ruminants caused by alcelaphine herpesvirus-1 (ahv-1), a virus of wildebeest. the disease also occurs in the absence of wildebeest and is then thought to be caused by a viral agent harboured by the sheep. the structural proteins of ahv-1 have been used as antigens for the immunoblotting analysis of sera from wildebeest, sheep and cattle infected by either ahv-1 or the "sheep-associated" form of the disease. wildebeest sera sho ...19892718352
fast elisa for measuring serum antibody responses.a method which speeds up the enzyme-linked immunosorbent assay (elisa) is described. the procedure uses a modified falcon fast assay screening system (becton dickinson labware, lincoln park, nj) and falcon round-bottom 96-well plates. antigen is adsorbed onto beads which extend from a lid and fit into 96-well plates. the beads are washed in a trough and reacted to antibody in the round-bottom plate. the labor required to wash the plates after coating with antigen, antibody or conjugate is thereb ...19892723439
analytical determination of methylated histidine in proteins: actin methylation.the methylation of histidine in actin from various muscle and nonmuscle sources has been studied by formation of phenylthiocarbamyl derivatives and subsequent reverse-phase high-pressure liquid chromatographic separation and analysis of actin hydrolyzates. all the actin species examined were found to contain 3-methylhistidine. this method has also been used in assays for the enzyme(s) responsible for methylation of rabbit skeletal muscle actin and to investigate the formation of other methylated ...19892729572
in vitro and in vivo comparison of the abilities of purine and pyrimidine 2',3'-dideoxynucleosides to inhibit duck hepadnavirus.four purine and two pyrimidine 2',3'-dideoxynucleosides were studied for their ability to inhibit duck hepadnavirus replication. the purine 2',3'-dideoxynucleosides were more potent antiviral agents than the pyrimidine 2',3'-dideoxynucleosides. the concentration for 50% inhibition of viral replication (ic50) was determined for each of the effective agents. two drugs with low ic50s, 2,6-diaminopurine 2',3'-dideoxyriboside and 2',3'-dideoxyadenosine, were chosen for in vivo studies. animals receiv ...19892729928
large phosphate shifts with treatment for hyperglycemia.although hypophosphatemia is known to commonly accompany therapy for hyperglycemia, it is not generally appreciated that severe life-threatening depletion of phosphate may occur. i followed up two patients who had precipitous drops during intravenous insulin therapy for diabetic ketoacidosis and hyperosmolar nonketotic state. the patient with diabetic ketoacidosis had a phosphate level nadir that equaled the lowest recorded phosphate level in a living human (0.03 mmol/l). because (1) serum phosp ...19892730261
relationship between multiple drug-resistance & enterotoxin production by shigella species.culture filtrates prepared with strains of shigella dysenteriae 1 and those of sh. flexneri and sh. sonnei, collected from different geographical locations in india caused accumulation of fluid in rabbit gut loops, indicating their capability to produce shiga and shiga-like toxins respectively. sh. boydii strains were noted for the first time to produce shiga-like toxins. the failure of production of fluid accumulation in rabbit gut by shigella strains that lacked the r-markers of the antibiotic ...19892737704
synaptic cytoarchitecture of the cat septum pellucidum. 19892747886
perioral anesthesia disrupts maternal behavior during early lactation in long-evans rats.the role of perioral somatosensory stimulation from pups in maternal behavior was investigated in lactating long-evans rats (rattus norvegicus) during early lactation by local anesthesia of the mystacial pads with lidocaine, which blocks conduction in the infraorbital nerve. it was concluded that (1) acute perioral anesthesia markedly inhibited pup retrieval when the subjects had no formal pretreatment retrieval experience. further, these dams displayed little tolerance to the lidocaine treatmen ...19892757582
relationship between concentration and anticonvulsant effect of phenytoin against electroshock-induced seizures in rats: comparison of sampling sites for concentration determinations.the purpose of this investigation was to determine the optimum sampling site for phenytoin concentration measurements in the context of pharmacodynamic studies of the anticonvulsant effect of phenytoin. determination of drug concentrations in the serum, serum water, brain, and cerebrospinal fluid (csf) of rats as a function of time after iv injection of a 6-mg/kg dose revealed a significant disequilibrium between brain and serum water for 15 min and between csf and serum water for 5 min after in ...19892760817
[infection caused by paracoccidioides brasiliensis in people living in cocle and veraguas, republic of panamá].intradermal application of yeast phase paracoccidioidin antigen obtained by sonication and lysis from the fungus to 111 residents of veraguas province (68 men and 43 women) and 130 cocle province residents (57 men and 73 women) elicited a positive reaction in 9.01% (1/111) and 26.15% (34/30) of the veraguas and cocle residents respectively. positive reactions ranged between papules of 5 and 27 mm in diameter, the majority being between 11 and 20 mm. infection was more frequent in men (1:1.47 for ...19892762594
determination of estradiol 2- and 16-alpha-hydroxylase activities in mcf-7 human breast cancer cells in culture using radiometric analysis.using a radiometric assay the effects of estradiol upon the activity of estradiol 2- and 16 alpha-hydroxylases in mcf-7 human breast cancer cells in culture were studied. after 5 days of treatment and 36 h of withdrawal, incubation in the presence of either 2- or 16 alpha-tritiated substrate was carried out. estradiol (10 nm) significantly increased 16 alpha-hydroxylase activity (21%, p less than 0.01), while no effects on 2-hydroxylase activity was observed. treatment for 6 weeks caused a major ...19892770303
twenty-year comparison of the human allograft and porcine xenograft.this study compares a retrospective consecutive series of human allografts and concurrent porcine xenografts implanted over a 10-year interval. there were 571 allograft valves and 1,351 xenograft valves implanted in the aortic and mitral position with mean follow-up of 12.8 years for the allografts and 6.2 years for the xenografts. this study compares the incidence of structural deterioration over long-term follow-up. we found that there was no significant difference between four manufacturers o ...19892774760
a strategy for high-volume sequencing of cosmid dnas: random and directed priming with a library of sequencing of cosmid dnas using a library of oligonucleotide primers of length 8, 9, or 10 is proposed. the statistics of priming indicate that a primer library sufficient for determining the sequence of the entire human genome (100,000 cosmids) would be small enough to be assembled and managed. such a library would greatly reduce the cost and effort of high-volume sequencing: primers would be instantly available; the sequence of each cosmid dna could be determined from a single dna prepa ...19892780548
neurochemical profile of moclobemide, a short-acting and reversible inhibitor of monoamine oxidase type a.moclobemide belongs to a new generation of short-acting, reversible, monoamine oxidase (mao) inhibitors. in vitro (rat brain homogenates) moclobemide inhibits mao-a selectively with lower potency than many of the reference mao inhibitors. however, when measured ex vivo in the rat, the potency of moclobemide is similar to that of reference compounds. in vivo the drug induces a dose-dependent, short-lasting (8-16 hr) and preferential inhibition of mao-a in the brain and both mao-a and mao-b inhibi ...19892783611
neurochemical profile of moclobemide, a short-acting and reversible inhibitor of monoamine oxidase type a.moclobemide belongs to a new generation of short-acting, reversible, monoamine oxidase (mao) inhibitors. in vitro (rat brain homogenates) moclobemide inhibits mao-a selectively with lower potency than many of the reference mao inhibitors. however, when measured ex vivo in the rat, the potency of moclobemide is similar to that of reference compounds. in vivo the drug induces a dose-dependent, short-lasting (8-16 hr) and preferential inhibition of mao-a in the brain and both mao-a and mao-b inhibi ...19892783611
co-localization of corticotropin-releasing factor- and enkephalin-like immunoreactivities in nerve cells of the rat hypothalamus and adjacent areas.the co-localization of corticotropin-releasing factor (crf)- and enkephalin (enk)-like immunoreactivities in nerve cells of the rat hypothalamus and adjacent areas was investigated by the simultaneous application of immuno-beta-galactosidase staining and the peroxidase-antiperoxidase (pap) method to the same sections. crf-like immunoreactive cells were stained blue with immuno-beta-galactosidase staining and enk-like immunoreactive cells brown with the pap method. double-labeled cells with overl ...19892786446
lymphokine-activated killer (lak) cells inhibit the clonogenic growth of human leukemic stem cells.the effect of lymphokine-activated killer (lak) cells on the in vitro clonogenic capacity of acute myeloid leukemia (aml) blasts was investigated in a semisolid medium assay. the leukemic clonogenic capacity of 11 aml cases, selected on the basis of their ability to grow in vitro, was highly reduced following overnight preincubation with lak effectors. the degree of colony inhibition, which ranged between 66% and 98% (mean 83.8% +/- 11.4 sd), was quantitatively greater than by 51cr release, whic ...19892786477
investigations of the potential for five beta-lactam antibiotics to elicit type ii hypersensitivity reactions in rats and monkeys.immunologic reactions are occasionally elicited in patients by various beta-lactam antibiotics (e.g., penicillins and cephalosporins). a relatively rare reaction (type ii hypersensitivity) may involve antibody-mediated destruction of erythrocytes, leukocytes, and/or platelets. during the safety evaluation of several modified beta-lactam compounds (carbapenems), hemolytic anemia and/or neutropenia were observed in rhesus monkeys, and anemia, neutropenia, and thrombocytopenia in rats, after approx ...19892786479
aging effects on secretory iga immune responses.studies of cellular and humoral components of the secretory immune system indicated dramatic decreases in the siga response to t-dependent antigens (i.e. dnp-bgg) in aged rats. senescent rats (18-20 months old) showed comparable levels of siga anti-dnp antibody to adult animals after oral immunization with a t-independent antigen, dnp-ficoll. the salivary siga responses to both antigens were substantially decreased in weanling rats (21-35 days) versus the adult rats. significant anamnestic siga ...19892786502
detoxification of lithocholic acid. elucidation of the pathways of oxidative metabolism in rat liver microsomes.the hydroxylation of lithocholic acid (3 alpha-hydroxy-5 beta-cholanoic acid) by adult male sprague-dawley rat liver microsomes supplemented with nadph was studied. metabolites were separated by a combination of thin-layer chromatography and high pressure liquid chromatography, both with and without prior methylation and acetylation of the samples. the resulting products were characterized by thin-layer, gas-liquid, and high pressure liquid chromatography by comparison with authentic bile acid s ...19892794781
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