Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| conversion of calciferols to isotachysterols by trifluoroacetic acid. | 2015 | 4540598 | |
| complementation between filamentous f-specific and i-specific bacteriophages. | 1972 | 4553629 | |
| [effect of humoral antibodies on the rejection of renal transplants]. | 1972 | 4572549 | |
| [suicide and attempted suicide. trends, statistics, prevention, help]. | 2015 | 4595018 | |
| how antagonistic can doctor's bias be on drug effect? oxazepam as an anti-anxiety agent. | 2015 | 4595191 | |
| brain cholesterol. xv. incorporation of specifically labeled glucose. | 2015 | 4635562 | |
| the effect of prolonged oral administration of oxytetracycline on the course of heartwater (cowdria ruminantium) infection in sheep. | 1972 | 4671467 | |
| the effect of dialysis on plasma and tissue levels of vitamin c. | 2015 | 4679880 | |
| response of body weight to a low carbohydrate, high fat diet in normal and obese subjects. | 2015 | 4703054 | |
| [active geriatrics. a visit to rotterdam]. | 2016 | 4706650 | |
| [embryodysplasia with features of incomplete albright's syndrome]. | 2015 | 4710712 | |
| [total invagination of the appendix, simulating a cecal neoplasm]. | 2016 | 4714895 | |
| mechanical factors influencing the holding power of screws in compact bone. | 1973 | 4729031 | |
| [lung function scintigraphy using 133 xenon. methods and first results]. | 2016 | 4739596 | |
| [spectroscopic study of some substituted n-(2-diethylamino-ethyl) benzamides]. | 2015 | 4774835 | |
| an analysis of meningitis cases admitted to strathclyde hospital, motherwell 1949-71. | 2016 | 4794861 | |
| the principle of the 'aérosol sonique'. | 2016 | 4795628 | |
| theory of competitive binding of iron by different transferrins. | 2016 | 4824920 | |
| supraclavicular catheterization of the superior vena cava. | 2016 | 4836144 | |
| structure of lettuce necrotic yellows virus. i. electron microscopy of negatively stained preparations. | 1967 | 4861247 | |
| [brill-symmers giant follicular lymphoma localized in pelvic lymph nodes]. | 2016 | 4882834 | |
| [anatomic diagnosis of hereditary nephritis. value and limitations of the conventional histopathologic methods]. | 2016 | 4885048 | |
| [50 years of soviet experimental surgery]. | 2015 | 4895659 | |
| [in memory of professor f. m. lampert]. | 2016 | 4910358 | |
| [certain aspects of the activity of a. a. bogomolets as the organizer and leader of a scientific school]. | 2016 | 4911466 | |
| [pathology and clinical aspects of malignant melanoma of the esophagus]. | 2016 | 4918008 | |
| [from the history of organization of public health in the far east]. | 2016 | 4918789 | |
| [computer technic in clinical electroretinography]. | 2016 | 4928997 | |
| [dr. frantisek jakes, m.d.--50th anniversary]. | 2016 | 4929933 | |
| [the cochlear duct in the monkey and dog]. | 1968 | 4970269 | |
| [review notes on toxoplasmosis]. | 2016 | 4987998 | |
| [nursing of severely burned children, with special reference to the recovery stage]. | 2016 | 4997789 | |
| dentist's libel action continues. | 2016 | 5040723 | |
| preparation of hepatic microsomal fraction for drug metabolism studies by rapid decompression homogenization. | 1972 | 5041006 | |
| studies on muscle rigidity: droperidol, diazepam, and promethazine. | 2016 | 5062116 | |
| the passage of cowdria ruminantium in mice. | 1971 | 5161403 | |
| [preservation of a cowdria ruminantium strain by freezing]. | 1970 | 5534034 | |
| [on the localization of cowdria ruminantium in the bronchial epithelium]. | 1966 | 6011928 | |
| cross immunity between strains of cowdria ruminantium. | cross immunity tests with strains of cowdria ruminantium from south africa, the sudan, são tomé and nigeria failed to demonstrate antigenic differences. the antibiotic ampicillin showed no activity against heartwater. | 1983 | 6195703 |
| virulence of two strains of cowdria ruminantium in mice and their use to predict drug activity against heartwater. | a study was made of the infectivity of two mouse-adapted strains of cowdria ruminantium in mice. the kwanyanga strain was most virulent in balb/c mice which died nine days after infection with homogenate of liver from infected mice. cd-1 mice were least susceptible of six strains tested. the du plessis strain of c. ruminantium was equally virulent in all six mouse strains. the du plessis strain in cd-1 mice was used as the basis of a drug screen to detect activity against heartwater (c. ruminant ... | 1984 | 6233776 |
| observation of rickettsia ruminantium in leukocytic cell cultures from heartwater-infected goats, sheep, and cattle. | 1983 | 6307094 | |
| heartwater (cowdria ruminantium infection): current status. | 1983 | 6359836 | |
| the immunization of calves against heartwater: subsequent immunity both in the absence and presence of natural tick challenge. | cattle, vaccinated as calves with cowdria ruminantium-infected tick stabilate, were challenged 6, 12 and 24 months later. in the absence of tick challenge, vaccination of calves induced a partial immunity against subsequent challenge at 12 and 24 months. in animals exposed to ticks, the resistance was no better than that of control, unvaccinated cattle. when they were challenged at 6 months of age there was no difference between vaccinated and unvaccinated calves, either in the absence or presen ... | 1984 | 6398415 |
| colostrum-derived antibodies to cowdria ruminantium in the serum of calves and lambs. | antibodies to cowdria ruminantium were detected in the serum of calves born from artificially immunized heifers, by means of the indirect fluorescent antibody test, only for as long as 4 weeks after birth. lambs born from artificially immunized ewes, however, were still serologically positive at 8-12 weeks of age. much higher antibody titres were recorded in the sera of ewes and their lambs than in that of heifers and their calves. | 1984 | 6533520 |
| heartwater in angora goats. i. immunity subsequent to artificial infection and treatment. | this study confirmed reports that angora goats are highly susceptible to cowdria ruminantium and showed that immunization of this breed against heartwater may be difficult hazardous. it was found that if goats were treated on the 2nd or 3rd day of the febrile reaction following the intravenous inoculation of the heartwater agent, few animals survived the infection. if, on the other hand, treatment was instituted on the 1st day of the reaction, the chances of survival were good, but the immunity ... | 1983 | 6634087 |
| isolation and transmission of cowdria ruminantium (causal agent of heartwater disease) in blue nile province, sudan. | heartwater was diagnosed in sheep at the umm banein livestock research station, blue nile province, sudan. cowdria ruminantium was isolated from sheep by subinoculation of blood into a goat. adult amblyomma lepidum ticks fed as nymphs on this goat transmitted heartwater to a friesian (bos taurus) calf. brain stabilates from this calf, either snap-frozen into liquid nitrogen or frozen slowly in a deepfreezer at -70 degrees c, with dmso as cryoprotectant, were infective to cattle when inoculated s ... | 1984 | 6740919 |
| experimental transmission of cowdria ruminantium by the gulf coast tick amblyomma maculatum: danger of introducing heartwater and benign african theileriasis onto the american mainland. | the tick amblyomma maculatum proved to be an experimental vector of cowdria ruminantium, the cause of heartwater of ruminants. transstadial transmission from larva to nymph and from larva through nymph to adult was successful; however, an experiment on transovarial transmission gave negative results. neither a americanum nor a cajennense transmitted the infection. there is a potential danger of the disease gaining access to the american mainland from the caribbean where it is known to occur and ... | 1982 | 6808870 |
| heartwater (cowdria ruminantium infection) on são tomé. | the supernatant obtained after centrifugation of an emulsion of engorged female amblyomma astrion ticks, collected from cattle on the west african island of são tomé, was injected intravenously into a goat, which contracted heartwater. this confirmation of the existence of the disease on the island makes strict control measures necessary if present efforts at improving livestock production by imported exotic cattle are to be successful. | 1982 | 7147672 |
| cowdria ruminantium (rickettsiales) in primary goat kidney cell cultures. | fresh or cryopreserved kidney tissue from goats suffering from heart water (cowdria ruminantium infection) was infective when inoculated intravenously into susceptible goats. primary kidney cell cultures were established from 14 goats reacting to c ruminantium infection; they were tested for infectivity by intravenous injection into susceptible goats after periods varying from five to 31 days. three cultures, five, 12 and 13 days old, induced heartwater in recipients. the other 11 cultures, vary ... | 1980 | 7255901 |
| some effects of 60co irradiation on cowdria ruminantium in its tick host amblyomma hebraeum koch (acarina: ixodidae). | an attempt was made to attenuate cowdria ruminantium by irradiation of the nymphal stage of its tick host, amblyomma hebraeum. the irradiated nymphs were homogenized and serial dilutions of the resultant suspension were injected intravenously into heartwater-susceptible sheep. no attenuation could be demonstrated but the results indicate that progressively more micro-organisms will be destroyed the higher the irradiation dosage applied, and that dosages between 20 and 30 kilorad apparently prove ... | 1981 | 7279384 |
| heartwater: cross-immunity studies with strains of cowdria ruminantium isolated in west and south africa. | 1981 | 7292612 | |
| a simple technique for the collection of brain samples for the diagnosis of heartwater. | a simple technique for the collection of brain samples for the post-mortem diagnosis of heartwater (cowdria ruminantium infection) is described. a sharp spoon (curette) or teaspoon and a knife are the only instruments required. after the head has been removed from the body a sample of cerebellar cortex is collected with the spoon through the foramen occipitale, thus obviating the need for opening the skull itself. this diagnostic technique appears to be as reliable as the convenient technique of ... | 1980 | 7368317 |
| [cowdriosis (heartwater) by cowdria ruminantium in ruminants of french indies (guadeloupe) and mascarene islands (la reunion and mauritius)]. | 1980 | 7455277 | |
| use of a specific immunogenic region on the cowdria ruminantium map1 protein in a serological assay. | currently available serological tests for cowdriosis (cowdria ruminantium infection) in domestic ruminants are hampered by their low specificities because of cross-reactivity with ehrlichia spp. the use of recombinant major antigenic protein (map1) of c. ruminantium for serodiagnosis was investigated. overlapping fragments of the map1 protein were expressed in escherichia coli and were reacted with sera from sheep infected with either c. ruminantium or ehrlichia ovina. two immunogenic regions on ... | 1995 | 7494037 |
| detection of cowdria ruminantium in blood and bone marrow samples from clinically normal, free-ranging zimbabwean wild ungulates. | cowdria ruminantium causes severe, often fatal disease in domestic ruminants, whereas wildlife species usually are not affected. blood and bone marrow samples from healthy, free-ranging zimbabwean ungulates were taken during translocation from areas harboring amblyomma ticks and tested for the presence of c. ruminantium, using a pcr assay based on the c. ruminantium map1 gene. positive reactions were obtained in tsessebe (damaliscus lunatus), waterbuck (kobus ellipsiprymnus), and impala (aepycer ... | 1995 | 7494060 |
| the cowdria ruminantium groe operon. | a cowdria ruminantium genomic dna library was constructed in the expression vector lambda zapii, and an immunoreactive clone, designated lambda cr9.4, was isolated by screening with serum from a c. ruminantium-infected goat. sequencing of the insert from this clone revealed two open reading frames, encoding peptides of 10462 and 58697 kda respectively. database searching indicated that the two genes were homologues of groes and groel, genes encoding a group of heat shock proteins involved in pro ... | 1995 | 7496520 |
| the detection of antibodies cross-reacting with cowdria ruminantium in the sera of domestic ruminants in regions of south africa where amblyomma hebraeum does not occur. | high levels of seropositivity, in all probability attributable to ehrlichia, were recorded in the serum of domestic ruminants throughout districts in south africa where amblyomma hebraeum, the vector of the heartwater agent, does not occur. the antibodies, detected with the indirect fluorescent antibody (ifa) and the indirect elisa tests, cross-reacted with cowdria ruminantium, which was used as antigen in both tests. a combination of the ifa and elisa tests, currently employed to detect antibod ... | 1994 | 7501358 |
| effects of tick infestation and tick-borne disease infections (heartwater, anaplasmosis and babesiosis) on the lactation and weight gain of mashona cattle in south-eastern zimbabwe. | the effects of ticks and tick-borne disease infections on the lactation and weight gain of mashona cattle were studied at mbizi quarantine station in the south-eastern lowveld of zimbabwe. twenty-nine mashona cows were allocated to 2 balanced groups and kept in separate paddocks at a stocking rate of one animal per 8 ha. one group received regular acaricide treatment to control bont (amblyomma hebraeum) and other ticks. the other group was left untreated. the cows were artificially inseminated. ... | 1995 | 7502343 |
| role of interferons in infectious diseases in the bovine species: effect on viruses and rickettsias. | successful protection was obtained with interferon treatment in experimental viral infections in the bovine species in a number of cases. the efficacy of the treatment against vaccinia virus infection and against rotavirus infection have been demonstrated. on the contrary, bovine herpes virus 1 (bhv 1-causing rhinotracheitis and part of the shipping fever complex) infections were not inhibited by interferon (ifn). the authors have undertaken a study in cattle in zimbabwe to assess the role of in ... | 1993 | 7510899 |
| 16s rrna gene sequence of neorickettsia helminthoeca and its phylogenetic alignment with members of the genus ehrlichia. | neorickettsia helminthoeca (tribe ehrlichieae, family rickettsiaceae) is the agent of salmon poisoning disease, which affects members of the family canidae. this bacterium is unusual in that it is the only known obligately intracellular bacterium that is transmitted via a helminth vector. the nucleotide sequence of the n. helminthoeca 16s rrna gene was determined and compared with the sequences of intracellular bacteria belonging to the alpha subgroup of the proteobacteria. the n. helminthoeca s ... | 1995 | 7537055 |
| comparison of two anticoagulants for production of antigens of cowdria ruminantium in neutrophils. | ethylene diamine tetra-acetate (edta) and lithium heparin were used comparatively as anticoagulants for blood obtained from goats clinically infected with cowdria ruminantium. neutrophils were extracted from the blood and cultured for the production of heartwater antigen. edta proved superior to heparin in terms of the recovery rate and the better separation of neutrophils from other leucocytes. the antigen produced was tested in the indirect fluorescent antibody test (ifat) and proved to be of ... | 1995 | 7569230 |
| the serological response to heartwater immunization in cattle is an indicator of protective immunity. | a significant correlation was demonstrated in friesian-cross steers between the serological response to previous vaccination with the ball 3 strain of cowdria ruminantium and the development of protective immunity against the kalota isolate from malawi. of 10 animals which seroconverted after vaccination, all were completely or partially immune to challenge. ten of the 14 animals which failed to seroconvert were immune but the proportion was not significantly different from that in the unvaccina ... | 1995 | 7569231 |
| studies of experimental infection and cross-immunity between stocks of cowdria ruminantium in sokoto red goats. | the course of experimental infection and cross-immunity tests between stocks of cowdria ruminantium were investigated using eight infected and four uninfected control sokoto red goats. all eight infected goats reacted to the primary infection. the incubation period varied between 8 and 23 days. during the febrile reaction, the highest rectal temperature recorded was 40 degrees c and the lowest was 39.7 degrees c, compared with a range of 38.6 +/- 0.15 to 38.1 +/- 0.19 in control goats. following ... | 1995 | 7571334 |
| laboratory reared amblyomma hebraeum and amblyomma variegatum ticks differ in their susceptibility to infection with cowdria ruminantium. | the susceptibility of laboratory reared zimbabwean amblyomma hebraeum and a. variegatum ticks to infection with geographically distinct cowdria ruminantium strains was investigated by feeding both species simultaneously on individual sheep infected with one of the four strains (crystal springs [zimbabwe], ball 3 [south africa], gardel [guadeloupe] and nigeria [nigeria]). a. hebraeum ticks demonstrated a high susceptibility to infection with all four c. ruminantium strains. in comparison, a. vari ... | 1995 | 7589273 |
| targeting ticks for control of selected hemoparasitic diseases of cattle. | development in and transmission of hemoparasites by tick vectors are phenomena closely synchronized with the tick feeding cycle. in all known life cycles, initial infection of tick tissues occurs in midgut epithelial cells and transmission is effected as ticks feed after parasites have developed and multiplied in salivary glands. many factors reviewed affect development and transmission of hemoparasites by ticks including age of ticks, artificial temperature, climate and/or season, tick stage or ... | 1995 | 7597779 |
| vector situation of tick-borne diseases in the caribbean islands. | the most important ticks transmitting diseases to ruminants in the caribbean islands are: amblyomma variegatum, vector of cowdriosis and associated with acute dermatophilosis; amblyomma cajennense, potential vector of cowdriosis; boophilus microplus, vector of babesiosis and anaplasmosis. at the present time, amblyomma variegatum is widespread in the lesser antilles from barbados to puerto rico. the intensity of the tick control program varies in the different islands and the tick infestation in ... | 1995 | 7597781 |
| current status of in vitro cultivation of cowdria ruminantium. | heartwater caused by cowdria ruminantium infection is the most important tick-borne disease of ruminants in southern africa. the in vitro culture system for this rickettsia, developed less than a decade ago, is responsible for the great majority of research accomplishments currently being reported in the areas of epidemiology, diagnosis and control of heartwater. despite this progress, cultivation of c. ruminantium remains more of an art than a science, inasmuch as significant discrepancies exis ... | 1995 | 7597785 |
| live vaccines against hemoparasitic diseases in livestock. | live vaccines against hemoparasitic diseases in livestock are based on parasites derived from culture (theileria annulata), from blood of infected animals (babesia bovis, babesia bigemina, anaplasma centrale, (attenuated) anaplasma marginale and cowdria ruminantium), and from ticks (theileria parva). the t. annulata attenuated cultured schizont vaccine is safe for all varieties of cattle. blood derived vaccines are recommended mainly for young cattle, the age limit varying with the different vac ... | 1995 | 7597786 |
| recent developments in the molecular biology of anaplasmosis. | recent applications of dna analysis, cloning, sequencing and expression technology have resulted in significant advances in our understanding of the hemoparasite anaplasma marginale. analysis of 16s ribosomal rna has confirmed a phylogenetic position close to ehrlichia sp. and cowdria ruminantium. intact genomic dna of a. marginale digested with sfii separates into bands from 14 to 170 kbp on pulse-field gels, with a total genome size of 1200-1260 kbp and g + c content of 56 mol%. major surface ... | 1995 | 7597790 |
| review of the molecular biology of cowdria ruminantium. | cowdria ruminantium is a rickettsial agent which causes heartwater, an economically important disease of livestock in the tropics and the caribbean. significant advances have been made in the molecular biology of c. ruminantium since its reproducible propagation in vitro in bovine endothelial cells. these advances have been targeted towards the development of improved vaccines and diagnostic tests. several immunogenic proteins of c. ruminantium have been identified and monoclonal antibodies have ... | 1995 | 7597792 |
| nucleic acid probes as a diagnostic method for tick-borne hemoparasites of veterinary importance. | an increased number of articles on the use of nucleic acid-based hybridization techniques for diagnostic purposes have been recently published. this article reviews nucleic acid-based hybridization as an assay to detect hemoparasite infections of economic relevance in veterinary medicine. by using recombinant dna techniques, selected clones containing inserts of anaplasma, babesia, cowdria or theileria genomic dna sequences have been obtained, and they are now available to be utilized as specifi ... | 1995 | 7597795 |
| correlation between antibodies to cowdria ruminantium (rickettsiales) in cattle and the distribution of amblyomma vector ticks in zimbabwe. | cowdriosis, caused by cowdria ruminantium, is transmitted by amblyomma ticks, which are widely distributed in zimbabwe. to assess the distribution of this disease in zimbabwe, cattle either exposed to amblyomma ticks or maintained in areas free from these ticks were tested for antibodies to cowdria. a total of 324 sera were tested using competitive elisa and the indirect fluorescent antibody test (ifat). at diptanks in amblyomma-infested areas 52% (n = 95) and 26% (n = 47) of sera were positive ... | 1993 | 7628226 |
| factors affecting the distributions of the ticks amblyomma hebraeum and a. variegatum in zimbabwe: implications of reduced acaricide usage. | the ticks amblyomma hebraeum and a. variegatum are the main vectors of heartwater, a disease of ruminants caused by cowdria ruminantium, in the agricultural areas of zimbabwe. at present, a. hebraeum is widely distributed in the dry southern lowveld, and occurs in at least seven foci in the higher rainfall highveld. amblyomma variegatum occurs in the zambezi valley and surrounding dry lowveld areas in the northwest. the distribution of a. hebraeum has changed considerably over the past 70 years, ... | 1994 | 7628253 |
| experimental trypanosoma congolense infection on naturally occurring ticks in n'dama and gobra zebu cattle. | the effects of experimental trypanosoma congolense infection in gambian n'dama and gobra zebu cattle on number of naturally-occurring adult ticks attaching were studied. an indirect fluorescent antibody test was performed to detect serological prevalence of cowdria ruminantium antibody. the intravenously imposed trypanosome infection did not result in significant (p > 0.05) differences in amblyomma variegatum and hyalomma spp. infestations between control and infected n'dama cattle. control n'da ... | 1994 | 7638002 |
| development and evaluation of pcr assay for detection of low levels of cowdria ruminantium infection in amblyomma ticks not detected by dna probe. | the sensitivities of a pcr assay and a dna probe assay were compared for the detection of cowdria ruminantium in amblyomma ticks that were fed on c. ruminantium-infected, clinically reacting, and recovered carrier animals. the pcr assay and dna probe detected infection in 86.0 and 37.0%, respectively, of 100 ticks fed on a febrile animal. in 75 ticks fed on carrier animals, pcr and the dna probe detected infection in 28.0 and 1.33% of ticks, respectively. this demonstrates that the dna probe has ... | 1995 | 7699036 |
| infection of bovine brain microvessel endothelial cells with cowdria ruminantium elicits il-1 beta, -6, and -8 mrna production and expression of an unusual mhc class ii dq alpha transcript. | cowdria ruminantium is a bacterial parasite that infects ruminants, causing an acute and often fatal disease. these obligate intracellular gram-negative bacteria preferentially infect neutrophils and vascular endothelial cells, especially in the brain. the present study was performed with bovine brain microvessel endothelial cells in culture, infected by c. ruminantium in the presence or absence of ifn-gamma. infection induced the production of il-1 beta, -6, and -8 mrnas, and this effect was po ... | 1995 | 7706742 |
| immunisation of sheep against heartwater with inactivated cowdria ruminantium. | the immunisation of sheep with inactivated cowdria ruminantium organisms (the causative agent of heartwater) emulsified in freund's adjuvant induced protective immunity against a homologous challenge with virulent cell culture-derived c ruminantium organisms. this protective immunity was associated with the development of high titres of c ruminantium-specific antibodies, a low level of rickettsiosis in brain endothelium and no mortalities. in contrast, when unimmunised sheep were challenged, the ... | 1995 | 7709059 |
| [field trial of an attenuated vaccine against heartwater disease]. | the results are given of a field trial using a senegalese stock of cowdria ruminantium which had been attenuated by passage in cell culture. thirty vaccinated and thirty control sheep were exposed in the niayes region of senegal and were monitored daily. in the control group, 22 animals died of heartwater, associated in one case with anaplasmosis. in the vaccinated group, 13 animals died; cowdria was found only in two sheep which had previously suffered from ehrlichiosis or anaplasmosis; three o ... | 1994 | 7770664 |
| microtubule associated protein map1a is an actin-binding and crosslinking protein. | high molecular weight microtubule-associated proteins map1a and map2 form thin projections from microtubule surfaces and have been implicated in crosslinking microtubules and other cytoskeletal components. we have purified native map1a from bovine brain and have studied its interaction with g- and f-actin. using a solid-phase immunoassay we show that map1a binds in a dose-dependent manner to both g-actin and f-actin. addition of map1a to f-actin causes gelation of f-actin and sds-page analysis s ... | 1994 | 7820861 |
| molecular cloning of a gene encoding the immunogenic 21 kda protein of cowdria ruminantium. | major immunogenic polypeptides (21, 32, 40, 46, 58, 85 and 160 kda) of cowdria ruminantium were identified by immunoprecipitation and immunoblotting. a puc13 library of c. ruminantium genomic dna was screened with hyperimmune sheep serum to identify escherichia coli colonies which expressed genes encoding these immunogenic proteins. a recombinant e. coli colony, f5.2, was identified containing plasmid insert dna of 2773 bp. the cloned dna insert contained two long open reading frames (orfs) of 6 ... | 1994 | 7921263 |
| effect of acaricide treatment of cattle on amblyomma variegatum (acari: ixodidae) infestation of mongooses (carnivora: viverridae: herpestes auropunctatus) in guadeloupe, french west indies. | the effect of acaricide treatment of cattle on the infestation of the small indian mongoose (herpestes auropunctatus hodgson) by amblyomma variegatum (f.) was determined during a field evaluation of selected acaricides in guadeloupe, french west indies. from april 1990 to april 1991, cattle at one site were treated every 14 d with pour-on formulations of deltamethrin, flumethrin, or permethrin; and cattle at a second site were treated as per a local standard treatment using a spray formulation o ... | 1994 | 8057326 |
| the immunoprotective anaplasma marginale major surface protein 2 is encoded by a polymorphic multigene family. | an anaplasma marginale florida msp-2 gene was cloned and expressed in escherichia coli. pulsed-field gel electrophoresis and southern blot analysis revealed the presence of multiple msp-2 gene copies that were widely distributed throughout the chromosomes of all three strains examined. genomic polymorphism among copies was greatest in the 5' end of msp-2 but also occurred in 3' regions. the presence of gene-copy-specific epitopes was indicated by the reactivity of the cloned msp-2 copy with some ... | 1994 | 8063397 |
| protection of goats against heartwater acquired by immunisation with inactivated elementary bodies of cowdria ruminantium. | in two experiments, four and five goats were vaccinated by giving two subcutaneous injections of a preparation of inactivated elementary bodies of cowdria ruminantium (gardel stock) mixed with freund's adjuvant. all vaccinated animals together with four naive controls were challenged intravenously with 5 ml of supernatant of a culture of bovine endothelial cells infected with the same stock of cowdria. all goats developed a high temperature. two out of four, and four out of five vaccinated goats ... | 1994 | 8066991 |
| reactivity of sera collected from dogs in mutare, zimbabwe, to antigens of ehrlichia canis and cowdria ruminantium. | six of 20 sera from apparently healthy dogs in mutare, zimbabwe, contained antibodies which were reactive with cowdria ruminantium and ehrlichia canis in indirect fluorescent antibody tests at similar titres. in western blots these sera recognised the immunodominant antigen bands of the two organisms. sera with high titres (> 1/80) recognised additional antigen bands of each organism. it was not possible to determine whether these dogs had been exposed to c ruminantium, e canis or other ehrlichi ... | 1994 | 8073593 |
| taxonomic position of the rickettsiae: current knowledge. | the term rickettsiae initially encompassed all intracellular bacteria. early rickettsial taxonomy was based on a comparison of a few phenotypic characteristics and recently, molecular studies brought new bases for rickettsial taxonomy. all rickettsial species studied so far belong to the alpha and gamma groups of the proteobacteria. ehrlichiae complex groups cowdria ruminantium, anaplasma marginale and wolbachia pipientis and the related parthenogenesis and cytoplasmic incompatibility bacteria, ... | 1994 | 8117465 |
| molecular cloning, sequence analysis, and expression of the gene encoding the immunodominant 32-kilodalton protein of cowdria ruminantium. | cowdria ruminatium, the causative agent of heartwater disease, expresses an immunodominant and conserved 32-kilodalton protein (map1; formerly called cr32), which is currently in use for serodiagnosis of the disease. the gene encoding this protein, designated map1, was detected, cloned, and characterized. the gene is conserved between four different stocks of c. ruminantium originating from senegal, sudan, south africa, and zimbabwe. homology searches revealed map1 to be homologous to the anapla ... | 1994 | 8132352 |
| detection of antibodies to cowdria ruminantium in the serum of domestic ruminants by indirect elisa. | a solid phase enzyme immunoassay for the detection of antibodies to cowdria ruminantium in the serum of domestic ruminants was developed by using microorganisms cultivated on bovine umbilical endothelial cells as antigen. when the culture showed 90% lysis, the supernatant was centrifuged, sonicated and coated on polystyrene microtiter plates. antibodies were detected as early as 9 days after experimental immunization of goats. the sensitivity of the elisa calculated with 73 ruminant sera ranged ... | 1993 | 8134621 |
| the sero-diagnosis of heartwater: a comparison of five tests. | five serological tests, the indirect and competitive elisa, the indirect fluorescent antibody (ifa) test with 2 different antigens and the western blot technique were compared and applied to sera that were known to be either negative or positive against cowdria ruminantium or that were collected from animals in heartwater-free regions. no false positive reactions were recorded with any of the tests against the known negative sera. except for minor variations in the sensitivity of the 5 tests, th ... | 1993 | 8134622 |
| the relationship between cowdria and ehrlichia: change in the behaviour of ehrlichial agents passaged through amblyomma hebraeum. | following an earlier report that an ehrlichia-like agent isolated from an adult hyalomma truncatum female became more pathogenic and elicited a disease in sheep indistinguishable from heartwater after having been passaged through amblyomma hebraeum, a similar phenomenon is herewith recorded. an ehrlichial agent demonstrated in the blood smear of a serologically positive, naturally infected lamb, changed in behaviour and assumed the characteristics of cowdria after passage through a. hebraeum. cr ... | 1993 | 8134623 |
| the immunodominant 32-kilodalton protein of cowdria ruminantium is conserved within the genus ehrlichia. | serological tests for cowdriosis are hampered by cross-reacting antibodies from animals suspected to be infected with ehrlichia species. we have monitored infections with ehrlichia bovis, e. ovina, e. canis and e. phagocytophila in experimental animals by competitive elisa, western blotting and immunofluorescence using cowdria-infected endothelial cell culture antigens. cross-reactions due to ehrlichia antibodies could be attributed to the recognition of epitopes on the immunodominant cr32 cowdr ... | 1993 | 8134624 |
| bovine and human endothelial cell growth on collagen microspheres and their infection with the rickettsia cowdria ruminantium: prospects for cells and vaccine production. | we successfully cultivated the rickettsia cowdria ruminantium, in bovine endothelial cell lines (bovine umbilical endothelial cells/buec and bovine microvasculature cells/bmc) and also in primary endothelial cells of bovine origin (bovine aorta endothelial cells/baec) and more surprisingly in cells of human origin--human umbilical vein endothelial cells/huvec--and human endothelial cells from the microvasculature/hemec. this first evidence of the pathogenicity of this bovine rickettsia in the hu ... | 1993 | 8134625 |
| isolation and characterization of antigenic proteins of cowdria ruminantium. | two antigenically conserved cowdria ruminantium proteins, an immunodominant 31 kda and a minor 27 kda protein, were characterized. the 31 kda and 27 kda proteins are single polypeptide chains. the 31 kda protein contains no glycoconjugates and the partial, internal amino acid sequence was determined. the acidic nature of this protein, deduced from the amino acid composition, was confirmed by ief (pi 5.7). monospecific antiserum was prepared against the 27 and 31 kda proteins and results indicate ... | 1993 | 8134626 |
| cloning and partial characterization of the cr32 gene of cowdria ruminantium. | cowdria organisms were purified by density gradient centrifugation. the dna was used to construct expression libraries. the immunodominant cr32 protein was purified and its n-terminal amino acid sequence was determined. the expression libraries were screened with cr32-specific monoclonal antibodies, but did not yield cr32-positive clones. therefore a part of the cr32-gene was amplified using primers derived from the n-terminal and an internal amino acid sequence. this dna was used as a probe to ... | 1993 | 8134627 |
| seroconversion to cowdria ruminantium of malawi zebu calves, reared under different tick control strategies. | the seroconversion by indirect elisa to cowdria ruminantium over the first year of life of sixty-six malawi zebu calves born into groups which were dipped 17 times per year was compared to seroconversion of 32 calves born into non-dipped groups. amblyomma variegatum tick counts and clinical disease in each group of cattle were monitored throughout the study period. no cases of heartwater were seen in either group of calves over the first 22 months of life. only one case of heartwater was observe ... | 1993 | 8134628 |
| cowdria ruminantium identified in amblyomma gemma using a dna probe pcs20. | amblyomma gemma ticks were collected from wild animals on a 20,000 acre game ranch in a heartwater endemic area in kenya, close to nairobi. a. variegatum is the main vector of heartwater in kenya. e.a. lewis, 1947, in a one sentence report has implicated a. gemma to be a vector of heartwater without giving any details. adult a. gemma were collected from giraffe giraffa camelopardalis, hartebeest alcephalus busephalus, eland taurotragus oryx and ostrich struthio camelus during cropping exercises. ... | 1993 | 8134629 |
| development and transmission of cowdria ruminantium by amblyomma males transferred from infected to susceptible sheep. | male amblyomma sp. were tested as vectors of cowdria ruminantium, causative agent of heartwater disease. the males were allowed to feed on sheep experimentally infected with c. ruminantium and then were transferred to susceptible sheep to test for transmission of the rickettsia. the experiments were done in two trials. in the first trial, a. hebraeum were exposed to the palm river stock of c. ruminantium, while in the second trial the kiswani stock of cowdria was tested with a. variegatum. ticks ... | 1993 | 8134630 |
| inhibition of cowdria ruminantium infectious yield by interferons alpha and gamma in endothelial cells. | we have shown before that there is a positive correlation between resistance of cattle against cowdria infection and early ifn production. our in vitro studies demonstrated an activity of rboifn alpha 2c and rboifn gamma against cowdria in bovine endothelial cells of brain microvasculature (bmec). rboifn gamma is much more active in this respect than rboifn alpha 2c. these results suggest a role of ifns in the resistance against the disease. strikingly, in the same conditions rboifn alpha 2c has ... | 1993 | 8134631 |
| the development of antibody to cowdria ruminantium in mice and its role in heartwater disease. | dba/2 and balb/c mice were used as a model to study the immune responses to cowdria ruminantium. both strains of mice were inoculated with 1, 10 or 100 ld50 of the crystal springs strain of c. ruminantium. antibody to c. ruminantium started to develop in the second week post-inoculation and the titre of the antibody was dependent on the inoculation dose of c. ruminantium. the possible role of antibody in heartwater disease was studied by in vitro neutralization assays using both mouse sera and b ... | 1993 | 8134632 |
| use of serological response to evaluate heartwater immunization of cattle. | frozen blood vaccine containing the ball 3 strain of cowdria ruminantium is prepared by an fao/danida project in malawi for the immunization of improved dairy cattle against heartwater. the immunogenicity of vaccine batches for cattle has been quantified and different regimens for immunization have been evaluated using indirect immunofluorescence to assess antibody responses. infected endothelial cells grown in culture are used as antigen. the proportion of animals responding serologically has v ... | 1993 | 8134634 |
| cowdriosis in senegal: some epidemiological aspects. | the results of a study on the abundance of amblyomma variegatum in different ecological zones and of cowdria ruminantium infection rates in nymphal and adult ticks of the north guinean zones are given. joint research is also conducted on the evaluation of seroprevalence. in this study, it appears that the vector is most important in the north guinean zone, followed by the south sudan and the coastal niayes zones. elsewhere, the tick populations are not significant or absent. the infection rate i ... | 1993 | 8134635 |