effect of quantity and quality of igg antibodies on blocking of allergenic histamine release in a study of the protective role of igg antibodies in allergen injection therapy, serum antibodies to timothy grass allergens were raised in rabbits and tested for inhibition of histamine release from basophils of grass pollen-sensitive human subjects. rabbit sera were not inhibitory until late in the immune response when large amounts of relatively low affinity igg antibodies were detected by primary binding. inhibition of histamine release by late sera required preincubation of allergen and a ...197984798
effects of antiprostatic agents on 5alpha-dihydrotestosterone binding to rat hypophyseal and hypothalamic cytosol macromolecules.the binding of 5alpha-dihydrotestosterone to the hypophyseal and hypothalamic cytosol macromolecules prepared from castrated male rats was observed. the effects of antiprostatic agents on 5alpha-dihydrotestosterone binding to both hypophyseal and hypothalamic cytosol macromolecules was examined. cyproterone acetate and chlormadionone acetate showed the significant inhibiting effects on 5alpha-dihydrotestosterone binding to 7-8 s macromolecules of cytosol from both hypophysis and hypothalamus. sc ...197986441
binding studies with antibodies having phosphorylcholine specificity and fragments derived from their homologous streptococcus pneumoniae type 27 capsular polysaccharide.the capsular polysaccharide from streptococcus pneumoniae type 27 (s-27) has been fragmented into oligosaccharides by controlled degradations. binding of these derived small ligands with heterogeneous rabbit anti-s-27 antibody of selected phosphorylcholine affinity indicates that a major immunodeterminant of s-27 is the phosphorylcholine moiety, but that these anti-pc. antibodies are also capable of binding to the polysaccharide backbone from which the p.c. has been removed.197987460
guinea pig transfer factor: restriction of macrophage migration inhibitory activity to extraordinary dilution confirmed with demonstration of diminished potency of stored preparations. 197988292
characterization of functional fc-receptor material from human lymphoblastoid cell lines. ii. serologic and cellular analysis. 197988475
reverse transcriptase-associated rnase h. part iv. pyrophosphate does not inhibit rnase h activity of amv dna polymerase. 197993479
effect on rats and mice of a diet with low tryptophan content (maize flour).female wistar rats when crowded together become aggressive if fed a diet with low tryptophan (trp) content (maize, flour, mf). when isolated during 30 days and fed mf they show a decrease of weight, of total plasma trp, and of trp and 5-hydroxytryptamine (5-ht) in brain stem, but 5-hydroxyindolacetic acid (5-hiaa) of the same cerebral area does not change. these results partially agree with other authors observations. mice isolated during 47 days and fed with mf do not show any significant weigh ...197995611
ultrastructural localization of calcium around the membrane of the surface connected system in the human platelet.the localization of calcium in the membrane system of human platelets was determined by ultrahistochemical methods equipped with an electron probe x-ray microanalyzer. after potassium oxalate-glutaraldehyde treatment large amounts of electron opaque precipitates were observed around the membrane of the surface connected system. electron probe x-ray microanalysis clearly defined that the precipitates were composed of calcium oxalate. the localization of calcium on the membrane of the surface conn ...197896043
an improved electrophoretic method for identifying antibiotics with special reference to animal tissues and animal feeding stuffs. 197897257
quantitative electron microscopic studies of the changes in rat hepatocytes following halothane induced anaesthesia. 197798410
[immuno-electro-diffusion on cellulose acetate membrane for serological testing in human malaria (author's transl)].an immuno-electro-diffusion assay for human malaria, using cellulose acetate gel, is described. more than 3500 sera have been tested by this method, which proved very useful for epidemiology since 400 sera a day can be tested by one person, with simple equipment. its sensitivity compared well to the ifa test, although the antibodies revealed are quite different. a constnat precipitin line appeared, against 56 degrees c labile antigens, in sera of subjects infected by p. falciparum, and up to 8 o ...197898748
guinea pig immunoglobulin light chain isotypes. i. separation of kappa and lambda chains and the identification of three isotypes of the lambda chain constant homology region.the separation of intact kappa chain and two fragments comprising lambda (lambda) chain from immunoglobulin light chain pools isolated from strain 13 guinea pigs is achieved by cyanogen bromide digestion and gel filtration before and after reductive clevage of disulfide bonds. the smaller lambda chain fragment derives from the original carboxyl-terminus of lambda chain. the partial sequence of component tryptic and thermolytic peptides of this thirty-nine residue fragment allowed its complete se ...1978103729
transfer of 2,4,5,2',4',5'-hexachlorobiphenyl and 2,2-bis-(p-chlorophenyl),1,1,1-trichloroethane (p,p'-ddt) from maternal to newborn and suckling rats.pregnant rats were given a small dose of 14c-2,4,5,2',4',5'-hexachlorobiphenyl (hcb) and 3h-ddt intraperitoneally. the transfer of hcb and ddt through the placenta and milk was then investigated. transfer through the placenta was 2.7 and 1.5% (respectively) of the initial doses; transfer through milk was 39.2 and 21.5%. hcb is obviously more transferable than ddt through the placenta and milk, the ratio of the amount of hcb transferred through milk to the amount transferred through the placenta ...1978104695
effects of chronic epileptic foci on control of pyramidal tract neurons in monkeys.five macaca mulatta monkeys were operantly conditioned to control the firing patterns of single precentral pyramidal tract neurons. the accuracy with which the monkeys could control normal ptns from within the focus was significantly poorer than ptns from contralateral, homotopic cortex. in comparison to nonepileptic monkeys, there was no significant difference in the accuracy with which ptns from cortex contralateral to interictal foci were controlled. by contrast, comparison of the time necess ...1978104868
the primary structure of lactobacillus casei thymidylate synthetase. ii. the complete amino acid sequence of the active site peptide, cnbr 4.the 102 amino acid residues of cnbr 4, the largest of 5 cyanogen bromide peptides from the lactobacillus casei thymidylate synthetase were completely sequenced by means of limited tryptic, tryptic, chymotryptic, and staphylococcal protease peptides. cnbr 4 contains both of the cysteines in an enzyme subunit, with the 5-fluorodeoxyuridylate-reactive cysteine at residue 198 and the other at residue 244.1979105004
a model of biliary pancreatic reflux.a primate model for the study of biliary pancreatic reflux under relatively physiological conditions is described. cannulas were inserted into the gallbladder and the common bile duct of rhesus monkeys, and a pedicled segment of small bowel was used to create a pancreaticocutaneous fistula after resection of the spleen and pancreatic tail. following recovery, hypaque was instilled into the gallbladder with maintenance of common duct pressure within a normal range. the pancreatic duct was visuali ...1979105415
interference of iodine-125 ligands in radioimmunoassay: evidence implicating thyroxine-binding globulin.although there is abundant published evidence that radioiodinated antigens interfere in digoxin radioimmunoassays, other radioimmunoassays are similarly affected. we investigated the relationship of radioiodinated antigen structure to its function in the immunoassay. carrier-free 125i-labeled iodotyrosine and iodohistamine derivatives were incubated with human serum, and the bound and free fractions were separated. we demonstrated that diiodotyrosyl analogs bind avidly to serum proteins. because ...1979108034
effects of deprivation on the visual cortex of cat and monkey. 1978108232
rapid serotyping of groups a, b, and c meningococci by rocket-line immunoelectrophoresis and co-agglutination.rocket-line immunoelectrophoresis (r-lie) with antigen containing intermediate gel, and co-agglutination utilising protein a-containing staphylococci coated with specific antibodies, were adapted for serotyping the prototypes of group b meningococci. both were found to have the same specificity as agar gel double diffusion (agdd) but they were more sensitive and more rapid than agdd. r-lie required, like agdd, the extraction of relatively large quantities of bacteria, while the co-agglutination ...1979108320
estrogenic properties of 3,9-dihydroxy-7,12-dimethylbenz[a]anthracene in rats.previously, the 3,9-dihydroxy derivative of benz[a]-anthracene was shown to be weakly estrogenic. the availability of the related diol of the mammary carcinogen dimethylbenz[a]-anthracene, i.e., 3,9-dihydroxy-7,12-dimethylbenz[a]anthracene (3,9-diohdmba), prompted a similar study of its estrogenic properties. the competitive binding studies of 3,9-diohdmba with 17beta-estradiol in the uterine cytosol of immature sd rats gave a ka of 1.7 x 10(8) m-1. 17beta-estradiol (10(-9) m) binding to the 8s ...1979108445
3'-terminal nucleotide sequence of alfalfa mosaic virus rna 4.the sequence of the 3'-terminal 91 nucleotides of alfalfa mosaic virus rna 4, the messenger for the viral coat protein, has been elucidated. a fragment containing the 3' terminus of the rna was obtained by mild digestion with rnase t1. the primary structure of the fragment was deduced by labeling it in vitro at its 5' terminus and application of rna sequencing techniques. the sequence is completely extracistronic and is believed to contain the binding sites for the viral coat protein and replica ...1979108677
[possible causes determining the developmental rhythm of populations of the nasopharyngeal gadfly of sheep, oestrus ovis l. (diptera, oestridae)].on the basis of observations undertaken in azerbaijan and available literary data the author considers the hypotheses concerning the reasons causing the delay of the ist instar larvae development and determining the age structure changes in population of oestrus ovis l. within a year. the main reasons are as follows: factors depending on the population density at the larval phase, the light day duration within the life cycle of the botfly females.1975124845
[morphological changes in the digestive organs during prolonged space flight on the kosmos-782 biosatellite].a reduction in the content of neutral mucopolysaccharides in mucous cells of the neck, a slight decrease in the activity of succinate dehydrogenase and nad-diaphorase in parietal cells, a decrease in the dna synthesis rate, and an increase in the area of mitochondria and cristae were detected in the gastric mucosa of rats which were in a long-term space flight. in the small intestine, an increase in the activity of glucose-6-phosphate dehydrogenase and leucine aminopeptidase were found. morpholo ...1978152100
[intravenous cholangiography in hyperbilirubinaemia (author's transl)].the effect of bilirubin on biliary and renal excretion of methylglucamine-iodipamide at an infusion rate of 1.3, 2.6 and 5.2 mu mol/min/kg was studied by intravenous injection into five dogs with normal liver functions and chronic duodenal fistulas. unconjugated bilirubin administered in a dose of 0.1 mu mol/min/kg reduced biliary iodipamide excretion and concentration significantly, but did not affect renal contrast material excretion. this indicates that the unsatisficatory radiological result ...1979153309
influence of anti-oestrogens on the specific binding in vitro of (3h)oestradiol by cytosol of rat mammary tumours and human breast carcinomata.the anti-oestrogenic potential of two nitrogen-mustard-containing compounds, i.c.i. 79792 and i.c.i. 85966, was studied. i.c.i. 85966 usually did not decrease specific binding of [3h]oestradiol by breast-tumour cytoplasmic proteins. i.c.i. 79792 decreased specific [3h]oestradiol binding, but not to the same extent as similar concentrations of i.c.i. 46474, diethylstilboestrol or dibutyldihydrostilboestrol.1975173302
alterations in myocardial and plasma cyclic adenosine monophosphate in experimental myocardial ischemia.alterations in myocardial and plasma cyclic adenosine monophosphate (cyclic amp) levels were studied following clamping of the aorta or coronary artery occlusion in 30 dogs. plasma cyclic amp levels increased markedly after thoracotomy but returned to control levels 2 hr later. complete arrest of aortic flow (clamping) induced a significant early increase in the myocardial cyclic amp levels of all animals studied. no increase was noted following pretreatment with propranolol or sham occlusion. l ...1975175414
malignant transformation-linked imbalance: decreased xanthine oxidase activity in hepatomas.xanthine oxidase was decreased 2- to 10-fold in all examined rat hepatomas irrespective of the malignancy; growth rate and degrees of histological differentiation of the neoplasms. the affinity to substrate (km=6-8 mum) and the ph optimum (8.0) of the liver and hepatoma enzymes were the same. the reprogramming of gene expression, as manifested in the decreased activity of this key purine metabolizing enzyme, appears to be specific to neoplastic transformation. since glutamine prpp amidotransfera ...1975179860
absorption of topically applied zinc and changes in zinc metabolism during wound healing. an experimental and clinical investigation. 1978281080
comparison of individual and cumulative dose-response curves [proceedings]. 1979497601
loss of absorptive capacity for sodium and chloride in the colon causes diarrhoea in potomac horse fever.ehrlichia risticii, an obligate intracellular bacterium in the family rickettsiaceae, causes potomac horse fever which is often associated with severe watery diarrhoea. the mechanism of the diarrhoea is unknown. the aim of this study was to determine whether sodium and chloride transport, morphology and cyclic adenosine 3', 5'-monophosphate (cyclic amp) content of colonic mucosa was altered in e risticii-infected horses. mucosa-submucosa sheets from the large and small colon of nine infected and ...19921352409
attempted mechanical transfer of ehrlichia risticii by tabanids (diptera: tabanidae).the ability of tabanid mouthparts to retain and to transfer mechanically ehrlichia risticii holland, weiss, burgdorfer, cole & kakoma was evaluated by feeding flies on infected and noninfected mice and on capillary tubes containing infected cells and cell-free medium. flies representing two genera and 29 species were collected at equine boarding stables, farms, and along riding trails in wake, johnston, and duplin counties in north carolina for the feeding trials. two species, tabanus fulvulus w ...19921404259
isolation of ehrlichia risticii from the aborted fetus of an infected mare. 19921441154
retrospective evaluation of factors associated with the risk of seropositivity to ehrlichia risticii in horses in new york state.a retrospective study was designed to determine the distribution of equine monocytic ehrlichiosis among the equine population in new york state, and to identify factors associated with risk of disease. serum samples submitted to the diagnostic laboratory of the university during the period from january 1985 through december 1986 were examined for antibodies to ehrlichia risticii, using the indirect fluorescent antibody technique. factors evaluated included geographic origin and date of submissio ...19921456543
effect of treatment with erythromycin and rifampin during the acute stages of experimentally induced equine ehrlichial colitis in ponies.sixteen healthy ponies were inoculated iv with ehrlichia risticii-infected p388d1 mouse monocytes. of the 16 ponies, 15 developed clinical signs of equine ehrlichial colitis. twenty-four hours after onset of fever (rectal temperature > 38.8 c), 7 ponies were treated with 25 mg of erythromycin stearate/kg of body weight and 10 mg of rifampin/kg, given orally every 12 hours for 5 days. the remaining 8 ill ponies served as nontreated controls. all ponies were observed for progression of clinical si ...19921466503
effect of treatment with oxytetracycline during the acute stages of experimentally induced equine ehrlichial colitis in ponies.eighteen ponies were inoculated iv with ehrlichia risticii-infected p388d1 mouse monocyte cells. twenty-four hours after onset of fever (rectal temperature > 38.8 c), 9 ponies were treated with oxytetracycline (6.6 mg/kg of body weight, iv, q 24 h) for 5 days. the remaining 9 ponies served as infected nontreated controls. mean scores of the following variables were not significantly different between groups on the day treatment was begun: rectal temperature, diarrhea, borborygmal sounds, feed in ...19921476312
presence of parasite antigen on the surface of p388d1 cells infected with ehrlichia risticii.indirect immunofluorescence staining of macrophages infected with ehrlichia risticii by anti-e. risticii serum revealed a punctate staining pattern on the surface of the host cell. this pattern was distinguishable by fluorescence microscopy from e. risticii bound to the surface of the macrophage and from intracellular e. risticii. the surface localization of ehrlichial antigen on infected macrophages was confirmed by electron microscopy with immunoferritin labeling. as the intracellular ehrlichi ...19921639476
antigenic and genomic relatedness among ehrlichia risticii, ehrlichia sennetsu, and ehrlichia canis.antigenic and genomic relatedness among ehrlichia risticii, e. sennetsu, and e. canis was analyzed by enzyme-linked immunosorbent assay, western blotting (immunoblotting) and dna-dna hybridization. e. risticii and e. sennetsu were serologically related, and their western blot antigen profiles were nearly identical. two antigens of e. sennetsu corresponding to the 28- and 51-kda antigens of e. risticii were apparently larger than the e. risticii antigens, and the 55-kda antigen of e. risticii app ...19921736961
serologically atypical canine ehrlichiosis associated with ehrlichia risticii "infection". 19911752762
equine monocytic ehrlichiosis (potomac horse fever): a the late 1970s, a new infectious disease in horses, involving acute enteritis, was recognised in the potomac river area of maryland, u.s.a. the causative agent was identified subsequently as a new species of rickettsial organism, later named ehrlichia risticii. since then, the disease has been reported in many other states, and in enzootic areas vaccination is common. signs associated with the clinical disease included depression, fever, anorexia, decreased or absent intestinal sounds, profus ...19911778155
pulmonary aspergillosis associated with acute enteritis in a horse.invasive pulmonary aspergillosis was detected at postmortem examination of an 8-year-old quarter horse mare that had a history of diarrhea, laminitis, and bilateral nasal discharge. a diagnosis of ehrlichia risticii infection was made on the basis of clinical signs of diarrhea and pyrexia, high serum antibody titer to e risticii (1:2,560), and multiple salmonella-negative cultures obtained from fecal and colonic specimens. possible pathogenic mechanisms contributing to the development of pulmona ...19911787116
[equine monocytic ehrlichiosis (eme), a review].serological surveys showed that equine monocytic ehrlichiosis (eme) occurs in the usa, canada and europe. the causative agent is rickettsia ehrlichia risticii, isolated for the first time in 1984. the clinical features of the disease are sluggishness, anorexia, colic and fever, possibly followed by watery diarrhoea. complications of an infection with e. risticii are laminitis and abortion. colitis of the ascending colon may be observed at autopsy. following a positive serological diagnosis (igm ...19911862502
protection against murine potomac horse fever by an inactivated ehrlichia risticii vaccine.ehrlichia risticii propagated in a murine macrophage cell line were freed from the host cell by hypotonic lysis of the infected cells. the cell-free ehrlichiae were inactivated with beta-propiolactone and combined or not combined with polymyxin-b. the vaccines were administered to mice with quil-a (saponin) as an adjuvant twice at 2 to 3 week intervals and the mice were challenged with live e. risticii 2 to 3 weeks after the last vaccination. with or without the addition of polymyxin-b, the vacc ...19911882507
biology of ehrlichiae.the isolation and cultivation of the agent of potomac horse fever, ehrlichia risticii, by holland, ristic, et al., afforded weisburg et al. an opportunity to examine its phylogeny. e. risticii is clearly related to the genus rickettsia and not to chlamydiae. a reevaluation of the significance of phenotypic characteristics is thus required, since ehrlichiae, in some respects, resemble chlamydiae. for example, unlike rickettsiae, ehrlichiae and chlamydiae multiply in the phagosome of their host ce ...19911884777
the tribe ehrlichieae and ehrlichial diseases.the tribe ehrlichieae consists of gram-negative minute cocci that are obligate intracellular parasites classified in the family rickettsiaceae. although ehrlichial organisms have been observed in leukocytes for many years, only a few species have been cultured in quantities sufficient for biochemical and molecular analyses. recents studies on 16s-rrna sequence analysis and energy metabolism showed that the genus ehrlichia is closely related to the genus rickettsia. there is, however, no antigeni ...19911889044
inhibition of ehrlichia risticii infection in murine peritoneal macrophages by gamma interferon, a calcium ionophore, and concanavalin a.ehrlichia risticii incubated with mouse peritoneal macrophages elicited with thioglycolate broth survived and replicated, thereby allowing examination of the effects of several immunopotentiating agents. treatment of the macrophages with recombinant murine gamma interferon (rmuifn-gamma) in vitro at 1 day before or 3 h after infection made the macrophages resistant to infection with e. risticii, and macrophages treated with rmuifn-gamma at 1 to 3 days after infection developed the capacity to er ...19911910000
diagnostic application of polymerase chain reaction for detection of ehrlichia risticii in equine monocytic ehrlichiosis (potomac horse fever).genomic amplification by the polymerase chain reaction (pcr) was used to identify a unique genomic sequence of ehrlichia risticii directly in dna isolated from peripheral-blood buffy coat cells of e. risticii-infected horses (potomac horse fever) and from infected cell cultures. a specific primer pair, selected from a cloned, species-specific, 1-kb dna fragment of the e. risticii genome as a template, was used for the amplification of the target dna of 247 bp. the optimal number of 40 pcr cycles ...19911939575
[a horse seropositive for ehrlichia risticii].a four year old dutch warmblooded mare was born and raised in the province of north-brabant, the netherlands. on may 16, 1989, she showed signs of colic, anorexia, depression, ileus, severe dehydration and leukopenia. when the mare collapsed, euthanasia was carried out. acute colitis and cytoplasmic inclusion bodies in macrophages were observed at autopsy. when an indirect immunofluorescence assay was performed, the ehrlichia risticii titre of the serum was found to be 1:640.19911996460
molecular cloning and analysis of recombinant major antigens of ehrlichia risticii.the genome of ehrlichia risticii, the etiologic agent of potomac horse fever, was cloned in the lambda gt11 expression vector. the efficiency of recombinant phage production with different restriction fragments of e. risticii dna was generally between 20 and 95%. the antigen-positive frequency, detected by immunoscreening with e. risticii antibodies, was between 8 and 40 per 10(4) recombinants. four (70, 55, 51, and 44 kda) major antigens of e. risticii were identified from the recombinant phage ...19911997417
haemoparasites of equines: impact on international trade of horses.the geographical distribution of babesia equi and babesia caballi and their tick vectors is discussed. control of infections with these protozoa is hampered by the lack of a suitable antiprotozoal drug and a reliable serological test. no vaccine is available. ehrlichia risticii (the causal agent of potomac horse fever) and e. equi are rickettsial parasites which are difficult to control. little is known of their geographical distribution and vectors. early diagnosis is required for tetracycline ...19902132711
ehrlichiosis--a disease of animals and humans.ehrlichiae are one of several kinds of obligate intracellular bacteria. taxonomically, they are grouped with rickettsiae, but they can be distinguished by their unique tropism for circulating leukocytes. ehrlichia canis causes a pancytopenia in dogs that becomes chronic if untreated. certain breeds develop severe infections, characterized by fever, anorexia, dramatic weight loss, marked pancytopenia, anemia, peripheral edema, and hemorrhage. ehrlichia risticii, a recently discovered species, is ...19902181027
serodiagnosis of equine monocytic ehrlichiosis in selected groups of horses in minnesota.antibody titer to ehrlichia risticii was determined, in 2,549 equine serum samples, using an indirect fluorescent antibody assay. during 1986, samples were obtained from the minnesota state-federal equine infectious anemia diagnostic laboratory, the minnesota racing laboratory, from horses admitted to the university of minnesota veterinary teaching hospital, and as a result of field investigations of horses with acute diarrhea. results of the study revealed antibody prevalence of 33, 24, 47, and ...19902195001
molecular cloning of ehrlichia risticii and development of a gene probe for the diagnosis of potomac horse fever.a gene bank of ehrlichia risticii was constructed in plasmid vector puc13. five clones representing discrete regions of the e. risticii genome were tested for their ability to hybridize specifically to e. risticii dna. none of the clones cross-hybridized with ehrlichia equi dna, whereas four of these clones cross-hybridized with ehrlichia canis and ehrlichia sennetsu dnas. however, one clone carrying a 1-kilobase hindiii fragment of e. risticii dna failed to cross-react with the genomes of e. se ...19902229378
attempted transmission of ehrlichia risticii (rickettsiaceae) with stomoxys calcitrans (diptera: muscidae).experimental transmission of ehrlichia risticii, the causal agent of potomac horse fever, was attempted with adult stable flies, stomoxys calcitrans, (l.) using two feeding schedules. in schedule a, a set of 140 flies was allowed to feed once on an experimentally infected donor pony and once 24 h later on a recipient pony. a different set of flies was used each day for a 12-d period. in schedule b, 240 flies were allowed to feed once daily for 12 consecutive d on the donor pony followed by five ...19902231623
attempted ehrlichia risticii transmission with dermacentor variabilis (acari: ixodidae).larval dermacentor variabilis (say) (n = 327) were fed on balb/c mice inoculated with ehrlichia risticii, the etiologic agent of equine monocytic ehrlichiosis (potomac horse fever). all mice displayed clinical signs of e. risticii infection at the time of feeding. after molting, resulting nymphs (n = 74) were fed on susceptible mice. no clinical signs were observed, and the mice remained seronegative for 6 wk after feeding.19902231630
dna restriction endonuclease cleavage pattern and protein antigen profile of ehrlichia risticii.molecular characterization of ehrlichia risticii, the etiological agent of potomac horse fever, was performed. restriction endonuclease cleavage of e. risticii dna generated distinct patterns by different enzymes. the dna cleavage patterns of e. risticii isolates obtained from different geographic regions were similar. protein analysis identified thirty-five distinct proteins with molecular weights ranging from 160 to 16 kilodalton (kda). antigenic analysis by radioimmunoprecipitation using 125i ...19902247934
serosurvey of horses with evidence of equine monocytic august 1986, an extensive serosurvey for prevalence of igg and igm antibodies against ehrlichia risticii, the causative agent of equine monocytic ehrlichiosis (eme), was performed at 2 ohio racetracks, river downs (rd) and beulah park (bp). of 840 horses at rd and 574 at bp, 13 and 20%, respectively, were igg antibody-positive (by indirect fluorescent antibody test results), with antibody titer ranging from 1:20 to 1:10,240. the titer observed at highest frequency at both racetracks was 1:80. ...19902266048
attempted transmission of ehrlichia risticii, causative agent of potomac horse fever, by the ticks, dermacentor variabilis, rhipicephalus sanguineus, ixodes scapularis and amblyomma americanum.dermacentor variabilis, rhipicephalus sanguineus, amblyomma americanum, and ixodes scapularis ticks were investigated for their ability to transmit potomac horse fever. larval and nymphal ticks were exposed to ehrlichia risticii by feeding on mice inoculated with the organism. molted exposed ticks were then allowed to feed on susceptible ponies or mice. no evidence of transmission, either clinically or by detection of antibodies to e. risticii in mice or ponies, was observed for any tick species ...19902307070
resistance to development of equine ehrlichial colitis in experimentally inoculated horses and ponies.fourteen ponies and 3 horses were inoculated with ehrlichia risticii 2 to 20 months after a similar initial inoculation. although all 17 had clinical signs of equine ehrlichial colitis after the first inoculation, 16 of 17 remained clinically normal following the second inoculation. the remaining pony had a transient fever and developed signs of depression. before the initial inoculation, none of the animals had a detectable antibody titer to e risticii. all animals developed titers after the in ...19902337274
gene amplification by polymerase chain reaction for detection of ehrlichia risticii dna in potomac horse fever. 19902378479
detection of ehrlichia risticii using an avidin-biotin-immunoperoxidase staining indirect immunoperoxidase procedure using a specific anti-ehrlichia risticii monoclonal antibody and an avidin-biotin-peroxidase staining method was used to detect e. risticii antigen in infected p388d1 murine monocytes. several different methods of cytological fixation were used, including acetone (15 min), 95% ethanol (15 min), bouin's fixative (5 hr), and 10% buffered neutral formalin (24 hr). the e. risticii organisms were labeled effectively and identified in cells fixed with acetone and ...19892484933
effect of antibiotics on clinical, pathologic and immunologic responses in murine potomac horse fever: protective effects of doxycycline.effects of three antibiotics on clinical, pathologic and immunologic responses in murine potomac horse fever caused by ehrlichia risticii infection were examined. when antibiotics were given after the development of clinical signs, antibiotics ranked in the order of reducing clinical signs and in preventing body weight loss and an intestinal enlargement were doxycycline, demeclocycline and rifampin. infected mice treated with doxycycline and demeclocycline developed greater splenomegaly than rif ...19892497577
monoclonal antibody-mediated, immunodiagnostic competitive enzyme-linked immunosorbent assay for equine monocytic ehrlichiosis.competitive enzyme-linked immunosorbent assay (celisa), mediated by a monoclonal antibody designated hybi, was developed for the diagnosis of equine monocytic ehrlichiosis. inhibition of binding of hybi by the horse antibodies to ehrlichia risticii was optimum at dilutions of 1:20 for serum and 1:10,000 for hybi. mean optical densities (ods) of positive and negative sera were 0.158 and 0.855, respectively. a comparison of ods obtained by celisa and indirect enzyme-linked immunosorbent assay (eli ...19892643624
white-footed mice: tick burdens and role in the epizootiology of potomac horse fever in hundred ten white-footed mice (peromyscus leucopus) were captured on horse farms in south-central maryland, examined for ticks, and tested for specific antibodies to ehrlichia risticii, the causative agent of potomac horse fever. peromyscus leucopus were consistently infested with immature american dog ticks (dermacentor variabilis), with monthly prevalences as high as 80%. sera from all 97 p. leucopus tested for antibodies to e. risticii were negative. this indicates that p. leucopus is not ...19892668569
monthly prevalence (in 1986) of antibody titers against equine monocytic ehrlichiosis in apparently healthy horses in illinois.the seroprevalence and seasonal trend of antibody titers against equine monocytic ehrlichiosis (potomac horse fever) were determined in apparently healthy horses in selected areas of illinois in 1986. sera from 1,367 horses (6 months to 29 years old) were evaluated for the presence of antibodies against ehrlichia risticii with indirect immunofluorescence. the majority (88%) of the horses were thoroughbred or standardbred racehorses. the number of horses with antibodies against e risticii was 229 ...19892694868
phylogenetic diversity of the rickettsiae.small subunit rrna sequences have been determined for representative strains of six species of the family rickettsiaceae: rickettsia rickettsii, rickettsia prowazekii, rickettsia typhi, coxiella burnetii, ehrlichia risticii, and wolbachia persica. the relationships among these sequences and those of other eubacteria show that all members of the family rickettsiaceae belong to the so-called purple bacterial phylum. the three representatives of the genus rickettsia form a tight monophyletic cluste ...19892753854
epidemiology of potomac horse fever: an investigation into the possible role of non-equine mammals.a serological study of antibodies to ehrlichia risticii was carried out on 10 species of wild and domestic mammals found on or near 21 horse farms in an area of the usa in which potomac horse fever is endemic. no antibodies were found in 133 peridomestic rodents (norway rats and house mice), nor in 108 wild rodents (white-footed mice and meadow voles) captured on farms. three of the six domestic animal species examined, cats, pigs and a goat, showed serological evidence of exposure to e risticii ...19892773237
antibody response to ehrlichia risticii and antibody reactivity to the component antigens in horses with induced potomac horse fever.the antibody response and the antibody reactivity to component antigens of ehrlichia risticii were studied in horses with induced potomac horse fever. these horses had no detectable antibodies to e. risticii in their preinoculation (pri) sera by indirect fluorescent-antibody assay and enzyme-linked immunosorbent assay (elisa). all the horses exhibited typical disease features following experimental infection and responded with specific antibodies, as measured by elisa and indirect fluorescent-an ...19892777369
energy metabolism of monocytic ehrlichia.we investigated if the monocytic ehrlichia are totally dependent on their host cells for energy, or, as rickettsia, are capable of some atp synthesis in vitro. the miyayama strain of ehrlichia sennetsu and the maryland and illinois strains of ehrlichia risticii were cultivated in a mouse macrophage cell line, separated from host cell constituents by procedures that included renografin or percoll gradient centrifugation, and tested after cryopreservation. cells incubated without a metabolizing su ...19892922404
susceptibility of cats to infection with ehrlichia risticii, causative agent of equine monocytic ehrlichiosis.eight adult cats were inoculated iv (n = 6) or sc (n = 2) with ehrlichia risticii-infected p388d1 (continuous murine macrophage) cells or with e risticii released from p388d1 cells. three additional cats were inoculated with organism-free p388d1 cultured monocytes, and 1 cat, which served as a medium control was inoculated with balanced salt solution. clinical signs of illness were observed in the iv inoculated cats from which e risticii was isolated. one cat developed intermittent diarrhea betw ...19883071194
challenging conventional aminoglycoside dosing regimens. the value of experimental models.although newer antimicrobials look promising for the treatment of serious gram-negative infections, aminoglycosides still remain part of the mainstay of their therapy. traditional intermittent therapy is based upon the premise that high serum aminoglycoside concentrations are toxic. however, the rate of bacterial killing for aminoglycosides is also a concentration-dependent phenomenon. two animal models of pseudomonas pneumonia were utilized to examine the efficacy of non-traditional aminoglycos ...19863089001
antibiotic sensitivity of pasteurella haemolytica isolated by means of a fibreoptic endoscope from cases of pneumonic pasteurellosis in cattle.bacterial isolations from tracheal and bronchial washes obtained with the aid of a fibreoptic endoscope were carried out over a 7 month period in a feedlot on calves suffering from acute pneumonic pasteurellosis. pasteurella haemolytica and pseudomonas aeruginosa represented the majority of isolates. antibiotic sensitivities of the pasteurella isolates are reported on.19873127766
effect of equine ehrlichial colitis on the hemostatic system in ponies.hemostatic function was determined in 10 ponies at various times after inoculation with ehrlichia risticii to determine whether equine ehrlichial colitis (eec) caused changes in the hemostatic system and to determine the prognostic value of hemostatic function tests during eec. mean platelet count; plasma fibrinogen, fibronectin, factor viii: coagulant, alpha 2-antiplasmin, and plasminogen values; and serum concentrations of fibrin/fibrinogen degradation products changed significantly (p less th ...19883138929
clinical, histopathological, and immunological responses of ponies to ehrlichia sennetsu and subsequent ehrlichia risticii challenge.ehrlichia risticii has a close antigenic relationship to e. sennetsu. sera of ponies experimentally infected with e. risticii, the etiologic agent of potomac horse fever, consistently reacted with e. sennetsu, a human pathogen, in indirect fluorescent-antibody (ifa) testing, while human e. sennetsu convalescent serum reacted with e. risticii by ifa testing and immunoferritin labeling of cells infected in vitro. two ponies injected intravenously with live e. sennetsu did no develop clinical illne ...19883169993
lack of lysosomal fusion with phagosomes containing ehrlichia risticii in p388d1 cells: abrogation of inhibition with oxytetracycline.fusion of lysosomes with phagosomes containing ehrlichia risticii, an obligate intracellular parasite, was evaluated in p388d1 murine macrophagelike cells. lysosomes in cells ranging in infectivity from 30 to 70% were labeled cytochemically with acid phosphatase or via endocytosis of thorium dioxide or cationized ferritin to document phagosome-lysosome (p-l) fusion in untreated cells and cells treated with oxytetracycline. regardless of the marker used, p-l fusion was generally not observed in e ...19883182078
disease features in horses with induced equine monocytic ehrlichiosis (potomac horse fever).fifty-five horses were inoculated iv and/or sc with materials containing ehrlichia risticii, ie, infected whole blood, buffy coat cells, or cell culture, to study clinical and hematologic features of equine monocytic ehrlichiosis (potomac horse fever). major clinical and hematologic features of induced e risticii infection were biphasic increase in rectal temperature with peak increases of 38.9 c and 39.3 c on postinoculation days (pid) 5 and 12, respectively; depression; anorexia; decreased wbc ...19883189992
susceptibility of dogs to infection with ehrlichia risticii, causative agent of equine monocytic ehrlichiosis (potomac horse fever).adult dogs 1 to 5 were inoculated iv and/or sc with 3, 5, or 6 ml of a suspension containing 1.2 x 10(4) ehrlichia risticii-infected cells (derived from primary canine monocyte cell cultures)/ml. dogs 6 to 8 were inoculated iv and/or sc with 3 or 6 ml of 1.2 x 10(5) organism-free cultured canine monocytes/ml. ehrlichia risticii was isolated in cultures from inoculated dogs 3, 4, and 5 on postinoculation days (pid) 10 to 16, but not from dogs 6 to 8. dogs inoculated with e risticii seroconverted ...19883223656
cytotoxic escherichia coli. 19873305326
equine ehrlichial colitis: effect of oxytetracycline treatment during the incubation period of ehrlichia risticii infection in ponies.equine ehrlichial colitis was experimentally induced in 18 ponies, using ehrlichia risticii-infected blood. four ponies (group 1) were treated with oxytetracycline (6.6 mg/kg of body weight, iv, q 12 h), beginning 14 hours before inoculation and continuing for 5 days after inoculation. four additional ponies (group 2) were treated similarly for 10 days after inoculation. the remaining 10 ponies were used as nontreated, infected controls. clinical disease was delayed in 3 group-1 ponies and in 4 ...19883356569
oral transmission of ehrlichia risticii resulting in potomac horse fever. 19883407128
diagnosis of equine monocytic ehrlichiosis (potomac horse fever) by indirect immunofluorescence.the recent establishment of a system for the continuous in vitro propagation of ehrlichia risticii, the causative agent of equine monocytic ehrlichiosis (eme; synonym, potomac horse fever), has facilitated the development of an indirect fluorescent antibody test for the diagnosis of this disease under laboratory and field conditions. the field diagnostic application of the test has aided in the recognition of the disease in 16 states of the united states and in 1 province of canada. a limited ep ...19863525479
enzyme-linked immunosorbent assay for potomac horse fever enzyme-linked immunosorbent assay (elisa) for immunoglobulin g (igg) and igm in natural and experimental infections of equids with ehrlichia risticii was developed. ehrlichial organisms purified from an infected mouse macrophage cell line were used as the antigen. igm was separated from serum igg by the expedient of spun-column chromatography, allowing the use of an indirect elisa for quantitation of both igg and igm in the test sera. among 16 paired sera from horses exhibiting clinical signs ...19873539995
isolation of ehrlichia risticii, the causative agent of potomac horse fever, from the fetus of an experimentally infected mare. 19873672833
equine ehrlichial colitis (potomac horse fever): recognition of the disease in pennsylvania, new jersey, new york, ohio, idaho, and connecticut.equine ehrlichial colitis (potomac horse fever), a newly identified colitis of the horse, was first recognized in maryland. in this report, we document occurrence of the disease in pennsylvania, new jersey, new york, ohio, idaho, and connecticut. enzootic areas were recognized by a characteristic pattern. frequently there was a seasonal pattern and high prevalence of sporadic colitis in unstressed horses. the attack rate per farm generally was low. horses on pasture, as well as those stabled, we ...19863744978
colitis: differential diagnosis and treatment.equine colitis characterised by diarrhoea and/or pain may be caused by a wide variety of bacterial, viral, protozoal agents and toxins. the causative agent of potomac horse fever, ehrlichia risticii, is the most recently recognised cause of colitis. salmonella, the agent typically associated with colitis, also causes abdominal pain (colic) of variable intensity. acute colitis is also caused by colitis x, various antibiotics, endotoxic shock and peritonitis caused by arterial infarction. the prin ...19863758005
attempted transmission of ehrlichia risticii by field-captured dermacentor variabilis (acari: ixodidae).the capability of field-collected american dog ticks, dermacentor variabilis, to infect horses with ehrlichia risticii, causative agent of potomac horse fever (phf), was examined by allowing adult ticks collected from horse farms with a history of phf to feed on susceptible horses. more than 500 male and female ticks attached and fed on 3 test horses; however, no clinical or serologic evidence of phf was observed in treated or control horses. all horses were challenge exposed with e risticii-inf ...19863789501
detection of serum antibodies against ehrlichia risticii in potomac horse fever by enzyme-linked immunosorbent indirect enzyme-linked immunosorbent assay (elisa) was developed which was specific and sensitive in detecting antibodies to ehrlichia risticii in potomac horse fever (phf). the elisa antibody titers were correlated with the indirect fluorescent antibody (ifa) titers. e. risticii propagated in human histiocyte culture was purified on renografin gradient and the band of the organisms at a density of 1.182 g/ml was used as antigen. elisa antibody titers were determined through computer assisted ...19873824902
potomac horse fever agent in mice. 19854082426
[infections due to "salmonella typhi murium" transmitted in pork]. 19704313632
[determination of the antigen of infectious canine hepatitis virus by the method of immunofluorescence]. 19724344940
[determination of the antigen of infectious canine hepatitis virus by the method of immunofluorescence]. 19724344940
effect of elemental diet on pancreatic secretion. 19744440810
non-existence of shunts between afferent and efferent arterioles of juxtamedullary glomeruli in dog and rat kidneys. 19724564193
[experimental study of rheumatic carditis using hemolytic streptococcus type 12]. 19744615378
evidence for the participation of a cholinergic receptor in adrenergic transmission. 19704319312
[the role of donor cells and antibodies in the resistance of animals--radiation chimeras to diphtheria toxin]. 19664906598
evidence for a high rate of false-positive results with the indirect fluorescent antibody test for ehrlichia risticii antibody in horses.the original objective was to determine seroprevalence of ehrlichia risticii antibody among horses in california. on the basis of the unexpected results of the survey, an investigation into the accuracy and reproducibility of results of the indirect fluorescent antibody (ifa) test for e risticii was carried out.19957493874
antigenic, morphologic, and molecular characterization of new ehrlichia risticii isolates.ehrlichia risticii causes an acute infectious disease in horses called potomac horse fever. to investigate the biological diversity of e. risticii organisms, nine e. risticii isolates derived from the peripheral blood monocytes of clinically sick horses in ohio and kentucky during the summers of 1991 and 1993 were compared with illinois and virginia isolates originally obtained from horses in maryland in 1984. seven of the nine isolates (081, 606, 380, 679, as, co, and ov) formed large morulae ( ...19947533780
effect of lysogenization on variability of phage type in rizobium meliloti. 19654159104
diversity of 16s rrna genes of new ehrlichia strains isolated from horses with clinical signs of potomac horse fever.ehrlichia risticii is the causative agent of potomac horse fever. variations among the major antigens of different local e. risticii strains have been detected previously. to further assess genetic variability in this species or species complex, the sequences of the 16s rrna genes of several isolates obtained from sick horses diagnosed as having potomac horse fever were determined. the sequences of six isolates obtained from ohio and three isolates obtained from kentucky were amplified by pcr. t ...19957537065
identification of ehrlichia risticii as the causative agent of two equine abortions following natural maternal infection.two pregnant mares diagnosed as having equine monocytic ehrlichiosis based on history, clinical signs, and high serum antibody titers to ehrlichia risticii aborted subsequent to recovery from illness. mare 1 and mare 2 experienced clinical illness at 120 and 143 days of gestation and aborted at 203 and 226 days of gestation, respectively. the fetuses were expelled in fresh condition, and both mares retained their placentas upon abortion. gross findings for the fetuses included meconium staining ...19957619902
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