| detection of the rocky mountain spotted fever agent, rickettsia rickettsii, in dead ticks, dermacentor andersoni. | rickettsia rickettsii remained viable and retained chromophilic properties for not more than 24 h after dermacentor andersoni were killed by freezing. antigenic reactivity was detected for at least 71 days by direct immunofluorescence. however, rickettsiae in ticks suffocated with mineral oil remained pathogenic for at least 14 days. accordingly, ticks removed from a host by mineral oil or dying from desiccation in transit are still suitable for rickettsial examination. | 1978 | 97233 |
| the influence of various factors on fluid secretion by in vitro salivary glands of ixodid ticks. | 1. salivary glands of the female ixodid tick, dermacentor andersoni, secrete fluid in vitro when bathed in a slightly modified version of the mammalian tissue culture medium 'tc 199'. 2. rate of salivation in vitro increases with progression of feeding, but there is no comparable increase in dry weight of the salivary glands during the early phase of engorgement. engorged ticks secreted at only 25% the rate of 90-250 mg ticks, indicating that salivary gland degeneration has already begun in the ... | 1976 | 180228 |
| the location of tick salivary antigens, complement and immunoglobulin in the skin of guinea-pigs infested with dermacentor andersoni larvae. | using indirect immunoflorescence techniques, tick salivary gland antigens (sga) were demonstrable in cement deposited on the skin by ticks and in all layers of the epidermis of infested guinea-pigs close to the sites where ticks attached. the antigen remained in these sites for several days after ticks had detached. in tick-resistant but not in normal guinea-pigs, sga, complement and igg were deposited at the dermo-epidermal junction even at some distance from the attachment site. complement was ... | 1979 | 391694 |
| nosema parkeri sp. n., a microsporidan from the argasid tick, ornithodoros parkeri cooley. | nosema parkeri sp. n. is described from nymphs and adults of the argasid tick, ornithodoros parkeri cooley, from a laboratory colony. schizogonic and sporogonic stages are described from various tick tissues. spores are binucleate, measuring 3.2 (3-4) x 1.9 (1.8-2.5) micronm. transmission is transovarial and transstadial. the parasite does not appear to affect adversely the development or reproduction of the tick. dermacentor andersoni stiles was experimentally infected. attempts to infect swiss ... | 1977 | 405484 |
| acquired resistance to ticks: expression of resistance by c4-deficient guinea pigs. | hartley and c4-deficient guinea pigs developed resistance to the ixodid tick. dermacentor andersoni, after one infestation. resistance was characterized by resistant animals of both groups allowing significantly fewer larvae (5--25%) to engorge during a second infestation than during an initial infestation (70--90%). resistant animals in both groups developed cutaneous reactions at the site of tick attachment which were characterized by intraepidermal vesicles containing numerous basophils. in p ... | 1979 | 453452 |
| comparisons of the foveae dorsales in male and female ixodid ticks amblyomma americanum, a. maculatum, dermacentor andersoni and d. variabilis (acari: ixodidae). | | 1979 | 537001 |
| the basophil response in blood and bone marrow of tick-infested guinea pigs. | the concentrations of basophils in blood and bone marrow were monitored in guinea pigs subjected to primary and secondary infestations with larvae of dermacentor andersoni. in these guinea pigs a significant increase of basophils was evident in peripheral blood. the response following the secondary infestation was more rapid and more intense than that following the primary infestation. similar changes were also shown to occur in bone marrow. the possible significance of these responses in relati ... | 1979 | 548160 |
| bovine anaplasmosis transmission studies conducted under controlled natural exposure in a dermacentor andersoni = (venustus) indigenous area of eastern oregon. | in anaplasma marginale transmission studies conducted on the high semi-arid range of eastern oregon during the 1974 and 1975 vector season, a marginale-susceptible calves (principals) were maintained on 2 raised tick-proof platforms. anaplasmosis-susceptible control calves of approximately the same age and latent-infected cows grazed the area surrounding the platforms. one latent-infected steer spent the entire 1975 vector season on a platform with the principals. the 28 principals did not devel ... | 1977 | 557939 |
| biochemical and physiological studies of certain ticks (ixodoidea). phospholipid classes in eggs, larvae, and hemolymph of argas (persicargas) arboreus (argasidae) and dermacentor andersoni (ixodidae). | | 1977 | 564965 |
| biochemical and physiological studies of certain ticks (ixodoidea). total lipids and phospholipids during oogenesis and embryogenesis of dermacentor andersoni (ixodidae) and argas (persicargas) arboreus (argasidae). | | 1977 | 606821 |
| acquired resistance to ticks. iv. skin reactivity and in vitro lymphocyte responsiveness to salivary gland antigen. | | 1978 | 627407 |
| acquired resistance to ticks. iii. cobra venom factor and the resistance response. | guinea-pigs developed resistance to larvae of the ixodid tick, dermacentor andersoni, after one infestation. resistant hosts were characterized by allowing significantly fewer larvae to engorge than non-resistant hosts. larvae engorging on non-resistant hosts had a mean weight six times that of larvae obtained from resistant hosts at the end of a 5-day infestation. this immunologically based resistance was previously shown to have a cell-mediated and a humoral component. in an attempt to ascerta ... | 1978 | 631873 |
| ultrastructure of the foveal glands of the ticks, dermacentor andersoni stiles and d. variabilis (say). | the foveal glands of dermacentor variabilis appear to consist of 2 cell types. the outer cells (type i) are active, with large areas of abundant finely granular material, apparently precursors of the mature secretory granules. the inner cells (type ii) are apparently storage cells. they are highly vacuolated and contain coarsely granular material as well as presumably mature secretory granules. the foveal glands of d. andersoni contain only type ii cells with extensive accumulations of presumabl ... | 1978 | 660384 |
| preparation of primary cultures of tick cells. | primary cell cultures were prepared from preimaginal bodies from the nymphal ticks, rhipicephalus sanguineus, dermacentor andersoni, and amblyomma maculatum, and from the hemocytes of late-stage nymphal and adult ticks, ornithodoros coriaceus. the dissection methods for obtaining preimaginal bodies and hemocytes for culture are described. a culture mediu, designated rml 375, was used for both culture methods. primary cultures were established with minimal contamination. preimaginal body cultures ... | 1978 | 697169 |
| biochemical studies of tick embryogenesis. free amino acid pools during embryogenesis of dermacentor andersoni. | | 1977 | 830483 |
| evaluation of free-roaming mule deer as carriers of anaplasmosis in an area of idaho where bovine anaplasmosis is enzootic. | samples of blood from 87 rocky mountain mule deer (odocoileus hemionus hemionus) were inoculated into 3 susceptible splenectomized calves to determine the anaplasmosis carrier status of the deer. the deer were trapped along the idaho-utah state boundary, near stone, id. acute anaplasmosis was induced in 2 of the 3 inoculated calves, and blood from the 3 calves caused anaplasmosis when inoculated into adult non-splenectomized cattle. serum rapid card agglutination testing revealed 13 (14.9%) posi ... | 1977 | 833034 |
| the distribution in oregon of ixodes pacificus, dermacentor andersoni, and dermacentor occidentalis with a note on dermacentor variabilis (acarina: ixodidae). | | 1977 | 845890 |
| dermacentor andersoni: culture of whole salivary glands. | | 1977 | 862699 |
| the influence of adrenergic agonists and their antagonists on isolated salivary glands of ixodid ticks. | various drugs elicit fluid secretion by isolated salivary glands of two species of ixodid ticks (dermacentor andersoni stiles and amblyomma hebraeum koch). among catecholamines, the following order of potency was observed: dopamine, epinine, noradrenaline = adrenaline and isoprenaline. the following drugs, in order of potency, were also agonists on this preparation: ergonovine, ergotamine, 6-hydroxydopamine, apomorphine, phenylephrine, norphenylephrine, beta-phenylethylamine, tyramine, d, l-dopa ... | 1977 | 891618 |
| distribution of suspected tick vectors and reported cases of rocky mountain spotted fever in california. | evidence is presented for an area of human risk to rocky mountain spotted fever (rmsf) in california extending beyond the range of its classic tick vector, dermacentor andersoni. geographic, seasonal, and host distributions of dermacentor variabilis and dermacentor occidentalis suggest these species as potential vectors of rmsf in california outside the range of dermacentor andersoni. | 1976 | 961695 |
| biochemical and physiological studies of certain ticks (ixodoidea). absence of sterol biosynthesis in dermacentor andersoni stiles (acarina: ixodidae). | | 1976 | 978697 |
| failure of anaplasma marginale theiler to survive natural winter conditions on a dermacentor andersoni = (venustus) infested range. | | 1976 | 1078097 |
| parasites of the black-tailed jackrabbit in north central colorado. | forty-four black-tailed jackrabbits, lepus californicus melanotis mearns, 1890, were collected near denver from august, 1972, through july, 1973, and amined for parasites. recovered parasites and their infection rates were: eimeria sp. 100%, cittotaenia sp.27%, coenuri of multiceps sp. 57%, cediopsylla inaequalis 14%, hoplopsyllus affinis 9%, haemodipsus setoni 2%, dermacentor andersoni 14%, and haemaphysalis leporis-palustris 25%. | 1975 | 1142561 |
| absence of anaplasma marginale infection in american bison raised in an anaplasmosis endemic area. | blood was collected at slaughter from 132 adult american bison (bison bison) raised in an anaplasmosis endemic area where the vector dermacentor andersoni (equals venustus) is indigenous. hematologic studies revealed no indication of clinical anaplasmosis. card agglutination and complement-fixation tests on all bison serums were negative. eleven anaplasmosis-susceptible calves each inoculated with 204 ml of blood pooled from 12 bison did not develop anaplasmosis. results of this study indicate a ... | 1975 | 1152178 |
| acquired resistance to ticks. i. passive transfer of resistance. | guinea-pigs developed resistance to larvae of the ixodid tick, dermacentor andersoni, after one infestation. resistance was characterized by guinea-pigs allowing fewer larvae to engorge (5-15%) during a second exposure than during an initial infestation (70-90%). larvae feeding on resistant hosts weighed less than larvae engorging on a host with no previous exposure to ticks. evidence is presented which indicates that this resistance can be passively transferred with viable lymph node cells, but ... | 1976 | 1254319 |
| contributions to the ecology of colorado tick fever virus. 2. population dynamics and host utilization of immature stages of the rocky mountain wood tick, dermacentor andersoni. | | 1976 | 1263215 |
| acquired resistance to ticks. ii. effects of cyclophosphamide on resistance. | guinea-pig developed resistance to dermacentor andersoni larvae after one infestation. cyclophosphamide administered in one dose (300 mg/kg) 48 hr prior to an initial infestation with larvae blocked the acquisition of resistance. when cyclophosphamide was given in a similar regimen to guinea-pigs which had already acquired resistance, the expressin of resistance was partially blocked. it was proposed that the blockage of the acquisition of resistance further confirmed the immunological nature of ... | 1976 | 1270085 |
| modulation of host-immune responses by ticks (acari: ixodidae): effect of salivary gland extracts on host macrophages and lymphocyte cytokine production. | ixodid tick infestation induces host acquired resistance, which involves immunoglobulin cell-mediated and complement-dependent effector pathways. ticks have developed countermeasures to modulate host antiarthropod responses. ixodid-mediated host immunomodulation results in vitro in reduced responsiveness to t-lymphocyte mitogens for cells obtained from infested hosts and impaired antibody responses to a thymic dependent antigen. salivary gland extracts from days 0-9 of engorgement from unmated, ... | 1992 | 1404261 |
| persistence of anaplasma marginale (rickettsiales: anaplasmataceae) in male dermacentor andersoni (acari: ixodidae) transferred successively from infected to susceptible calves. | the persistence of anaplasma marginale theiler in male dermacentor andersoni stiles ticks exposed to the organism as adults was studied as the ticks were successively transferred to five susceptible calves. all calves fed upon by these ticks rapidly developed clinical anaplasmosis; incubation periods of infection ranged from 19 to 26 d and did not change significantly with successive feedings. development of a. marginale in tick midgut and salivary glands was followed daily during tick feeding ( ... | 1992 | 1495076 |
| detection of rickettsia rickettsii in saliva, hemolymph and triturated tissues of infected dermacentor andersoni ticks by polymerase chain reaction. | the technique of polymerase chain reaction (pcr) is potentially superior to existing methods for detecting rickettsial infections in ticks. for this reason, we developed assays for identifying rickettsial infections in ticks by pcr. our assays amplified a 500 bp fragment from the gene encoding the romp b protein of rickettsia rickettsii. the selected primers amplified fragments of the predicted size from all spotted fever group rickettsiae (r. rickettsii, r. parkeri, r. conorii, r. sibirica) tes ... | 1992 | 1528203 |
| development of anaplasma ovis (rickettsiales: anaplasmataceae) in male dermacentor andersoni (acari: ixodidae) transferred from infected to susceptible sheep. | the development of anaplasma ovis was studied in dermacentor andersoni males transferred from infected to susceptible sheep. laboratory-reared male d. andersoni were allowed to feed for 6 d on a sheep with ascending a. ovis parasitemia. the ticks were removed and held at room temperature in a humidity chamber for 6 d, after which they were allowed to feed on five susceptible sheep for 1, 3, 5, 7, or 9 d. gut and salivary glands were collected from ticks during the 21-d experiment and examined wi ... | 1992 | 1552534 |
| development of anaplasma marginale in male dermacentor andersoni transferred from parasitemic to susceptible cattle. | the development and transmission of anaplasma marginale was studied in dermacentor andersoni males. laboratory-reared male d andersoni were allowed to feed for 7 days on a calf with ascending a marginale parasitemia. the ticks were then held in a humidity chamber for 7 days before being placed on 2 susceptible calves. anaplasmosis developed in the calves after incubation periods of 24 and 26 days. gut and salivary glands were collected from ticks on each day of the 23-day experiment and examined ... | 1992 | 1586018 |
| recent advances in the biology of anaplasma spp. in dermacentor andersoni ticks. | | 1992 | 1626880 |
| ivermectin is not an agonist at a gaba receptor in tick salivary glands. | the avermectins, broad-spectrum anti-parasitic agents which are effective against ticks, act principally by stimulating gamma-aminobutyric acid (gaba) receptors directly or indirectly. gaba is known to potentiate dopamine-induced fluid secretion in the salivary glands of female ixodid ticks. we thus tested whether 10 microm ivermectin would have an effect similar to gaba in the isolated salivary gland preparation of dermacentor andersoni. ivermectin was not an agonist at this gaba receptor. | 1991 | 1660804 |
| horizontal movement of adult ixodes dammini (acari: ixodidae) attracted to co2-baited traps. | the ability of male and female deer ticks, ixodes dammini spielman, clifford, piesman, & corwin, to move horizontally was evaluated by performing a mark-recapture study. in each of two experiments, 120 ticks were marked with fluorescent powder and released at predetermined distances from a co2-baited trap. the mean recruitment distance was 1.8 m after 6 d of trap operation. this distance is appreciably lower than those calculated from previous studies of several other species of ixodid ticks, in ... | 1991 | 1941943 |
| factors v and vii anticoagulant activities in the salivary glands of feeding dermacentor andersoni ticks. | the salivary glands of dermacentor andersoni ticks possess anticoagulant activities that can alter the clotting time of rabbit whole blood. salivary gland extracts from female ticks inhibit both the intrinsic and extrinsic coagulation systems, and maximal activities against both pathways occur when the ticks attain about 250 mg feeding weight. these anticoagulants are directed against both coagulation factors v and vii, but they do not affect factors ii or x. despite this salivary anticoagulant ... | 1991 | 1992089 |
| nonspecific activation of complement factor 5 by isolated dermacentor andersoni salivary antigens. | salivary gland extracts from feeding dermacentor andersoni ticks contain an activity that activated both rabbit and human complement to produce inflammatory cell chemotactic activity. purified salivary antigens (sga), isolated from the glands of female ticks with anti-saliva immunoglobulins from tick-resistant rabbits, also induced chemotactin generation. it has been demonstrated previously that the intradermal injection of such sga into normal animals induces nonspecific inflammatory reactions ... | 1991 | 2010863 |
| rocky mountain spotted fever. | rocky mountain spotted fever is an endemic tickborne disease found throughout the united states and other regions of the world. exposure may result in a spectrum of disease from subclinical infection to severe or fatal multiorgan collapse. the disease is maintained in nature in ixodid tick vectors and their hosts. the most important ticks in the united states are dermacentor variabilis and dermacentor andersoni. small mammals are the natural reservoirs in the wild. dogs become infected when a ti ... | 1991 | 2014623 |
| tick information sheet. the rocky mountain wood tick. dermacentor andersoni. | | 1991 | 2014625 |
| differential effects of photoperiod on development and reproduction in "montane" and "prairie" strains of the rocky mountain wood tick (acari: ixodidae). | progeny of dermacentor andersoni stiles adults collected from one "montane" and two "prairie" sites in southern alberta, canada, were exposed to combinations of 9:15, 11:13 and 13:11 (l:d) daily photoperiods during various stages of their life cycle. time required for developmental and reproductive events was recorded. significant differences in mean molting times of fed larvae were observed, yet the differences were small, and mean times were not attributed to photoperiodic regime. fed nymphal ... | 1991 | 2033610 |
| intermediate site of development of anaplasma marginale in feeding adult dermacentor andersoni ticks that were infected as nymphs. | the development of anaplasma marginale in midgut epithelial cells was studied in feeding, transmitting adult dermacentor andersoni ticks. laboratory-reared ticks experimentally infected as nymphs were allowed to feed from 1 to 9 days on susceptible calves. gut tissues from ticks were collected on each day they fed (total, 9 days) and were processed for light and transmission electron microscopy. colonies of a marginale were abundant during the first 6 days of feeding, after which numbers decreas ... | 1990 | 2301812 |
| development and infectivity of anaplasma marginale in dermacentor andersoni nymphs. | the development of anaplasma marginale was studied in dermacentor andersoni nymphs after they had fed on a calf with ascending anaplasma infection. gut tissues were collected on day 4 of tick feeding, from newly replete (fed) nymphs and on postfeeding days (pfd) 5, 10, 15, 20, and were processed for light and electron microscopy to determine density of a marginale colonies. homogenates of gut tissues were prepared from nymphs collected on the same days and inoculated into susceptible, splenectom ... | 1990 | 2386330 |
| presence of common antigens, including major surface protein epitopes, between the cattle (intraerythrocytic) and tick stages of anaplasma marginale. | epitopes of major surface proteins of the intraerythrocytic cattle stage of anaplasma marginale were demonstrated in the midgut stage of the organism within the infective tick host dermacentor andersoni. these proteins were common to all a. marginale isolates tested and at all stages of parasitemia. sera from cattle immunized with the tick midgut stage of a. marginale immunoprecipitated multiple-erythrocyte-stage proteins, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophore ... | 1985 | 2415457 |
| preliminary studies of the development of anaplasma marginale in salivary glands of adult, feeding dermacentor andersoni ticks. | on each day of feeding on susceptible calves, salivary glands obtained from groups of adult ticks that transmitted anaplasma marginale were examined for a marginale colonies by use of light microscopy and transmission electron microscopy. on day 8 of feeding, salivary glands were examined, using fluorescein-labeled antibody and methyl green-pyronine stain. use of fluorescein-labeled antibody consistently revealed small numbers of fluorescent foci in salivary gland acinar cells obtained from tick ... | 1988 | 2458688 |
| experimental infection of six species of ixodid ticks with dugbe virus (family bunyaviridae, genus nairovirus). | the vector potential of each of 6 species of colonized north american and african ixodid ticks was assessed by intracoelomic inoculation with dugbe virus (ibar 1792, 14th passage in suckling mouse brain) and viral titers were monitored after selected incubation periods. persistence of dugbe virus for greater than or equal to 53 days in 5 species (dermacentor andersoni, d. variabilis, amblyomma americanum, rhipicephalus appendiculatus, and r. sanguineus) indicates that infection occurred. viral t ... | 1989 | 2496609 |
| the population dynamics of two vertically transmitted infections. | the transmission of keystone virus in the mosquito aedes atlanticus and of rickettsia rickettsii in the tick dermacentor andersoni is modeled and analyzed. both of these infections can be transmitted vertically from an infective parent to newborn offspring as well as horizontally via direct or indirect contacts with infected individuals. the vertical transmission mechanism plays a major role in the maintenance of these infections and its effects are analyzed in detail. this same mechanism can ac ... | 1988 | 3148206 |
| hybridization of dna probes to a. marginale isolates from different sources and detection in dermacentor andersoni ticks. | dna from the washington, south-idaho, virginia and florida isolates of anaplasma marginale was hybridized to probes specific for anaplasma centrale and a. marginale. the a. centrale probes ac-2 and ac-4 hybridized to identical bands on all of these isolates. the hybridization patterns suggests that the virginia, florida and the south african isolates are similar. a number of bands were obtained with the washington isolate which differed from those obtained with the other isolates. probe ac-2 cou ... | 1988 | 3217095 |
| isolation and characterization of salivary antigens from the female tick, dermacentor andersoni. | the salivary glands of ixodid ticks are complex organs which are known to contain the antigens responsible for tick resistance in animals. we have identified a large number of proteins from salivary gland extracts (sge), at least some of which are immunologically recognized by tick resistant animals and which are therefore presumed to be secreted salivary components. during the 6 to 10 day feeding process, a number of these antigens alter in concentration according to individual kinetics, and so ... | 1987 | 3299226 |
| the effect of avermectins on feeding, salivary fluid secretion, and fecundity in some ixodid ticks. | we tested the effects of the potent acaricides, avermectin b1a (avm) and 22,23-dihydroavermectin b1 (ivermectin; ivm) when injected directly into partially fed and fully engorged female ticks. when injected into small ticks (amblyomma hebraeum koch), neither drug (up to 100 micrograms/kg b.w.) inhibited subsequent engorgement nor affected oviposition latency, weight of total egg mass laid nor viability of laid eggs. at higher concentrations (1000 and 5000 micrograms/kg b.w.), avm and ivm were ma ... | 1986 | 3451859 |
| biochemical studies on tick embryogenesis: lipovitellin and protease activity in dermacentor andersoni (acari: ixodidae). | | 1986 | 3525840 |
| ectoparasites of black-tailed prairie dogs (cynomys ludovicianus) from south dakota. | during the summers of 1982 and 1983, black-tailed prairie dogs (cynomys ludovicianus) were examined for parasites. those collected and their respective prevalence included linognathoides cynomyis (46.3%), opisocrostis hirsutus (53.7%), opisocrostis tuberculatus cynomuris (2.4%), androlaelaps fahrenholzi (12.2%), ixodes sculptus (2.4%) and dermacentor andersoni (4.9%). the collection data indicated that l. cynomyis, o. hirsutus and a. fahrenholzi were at low population densities during this perio ... | 1987 | 3586214 |
| attempted transmission to cattle of anaplasma marginale from overwintered dermacentor andersoni ticks. | since the 1983 summer outbreak of anaplasmosis in southern saskatchewan, the role of the tick, dermacentor andersoni as an overwintering reservoir for anaplasma marginale has been questioned. the purpose of this study was to determine if spring-collected ticks carried virulent a. marginale. sixteen splenectomized calves were assigned randomly to two groups of 14 principals and two controls. adult d. andersoni, collected in april from areas having high transmission rates of a. marginale, were con ... | 1987 | 3651893 |
| absence of assembly pheromones in the hard ticks dermacentor variabilis and dermacentor andersoni (acari: ixodidae). | | 1987 | 3694628 |
| dot-elisa assessment of guinea pig antibody responses to repeated dermacentor andersoni infestations. | acquired resistance to ixodid tick infestation is expressed by cattle and laboratory animals. humoral factors appear to be involved in host acquired resistance to tick bite; however, specific immune responses have yet to be fully characterized. this study examined tick resistance expressed by hartley guinea pigs upon repeated infestation with dermacentor andersoni, and describes longitudinal development of antigen specific immunoglobulin over approximately 180 days. guinea pigs were infested eit ... | 1986 | 3712171 |
| longevity of colonies of anaplasma marginale in midgut epithelial cells of dermacentor andersoni. | colonies of anaplasma marginale in midgut epithelial cells of experimentally infected dermacentor andersoni were studied in adult ticks 1, 3, and 6 months old. longevity of the parasite in ticks was assessed by evaluating its infectivity for splenectomized calves; calves were exposed by feeding ticks and by inoculation of tick gut homogenates. longevity was also evaluated by determining size, type, and density of colonies in male and female ticks. the effect of incubation (2.5 days at 37 c) on c ... | 1986 | 3752671 |
| percutaneous infection of nymphal dermacentor andersoni with anaplasma marginale. | newly replete nymphal dermacentor andersoni (principals) were percutaneously exposed to anaplasma marginale by injection of either intact or lysed infected bovine erythrocytes. control nymphs were fed on calves with anaplasmosis. the subsequently molted adults were examined for infection by light microscopy, and companion ticks were tested for infectivity by allowing them to feed on susceptible calves. when they fed as adults, both control ticks and percutaneously inoculated principals transmitt ... | 1986 | 3752672 |
| transmission of anaplasma marginale theiler by males of dermacentor andersoni stiles fed on an idaho field-infected, chronic carrier cow. | the role of ticks and carrier cattle in epizootics of bovine anaplasmosis was further clarified by demonstrating unequivocally, for the first time, that male ticks fed on a chronic carrier cow naturally infected with anaplasma marginale can transmit this parasite intrastadially and biologically when subsequently fed on susceptible cattle. these data indicate that field epizootics of acute anaplasmosis may be initiated by males of tick vector species that feed on carrier cattle and subsequently t ... | 1986 | 3777655 |
| infectivity of three anaplasma marginale isolates for dermacentor andersoni. | three isolates of anaplasma marginale--virginia (vam), illinois (iam), and florida (fam)--were compared for infectivity for dermacentor andersoni. the isolates were selected, in part, because of a tail-like appendage that has been demonstrated in the vam and iam, but not in the fam. ticks were exposed to the isolates as nymphs either naturally by feeding on a calf with anaplasmosis or artificially by percutaneous inoculation with infected bovine erythrocytes. they were examined for infectivity a ... | 1987 | 3826850 |
| effects of tick infestation on the plaque-forming cell response to a thymic dependent antigen. | strain-2 guinea-pigs were given two five-day infestations with dermacentor andersoni larvae. each exposure consisted of 100 larvae, and the first and second infestations were separated by a seven-day tick-free period. tick-exposed animals were given an intravenous injection with sheep red blood cells (srbc) at selected times during and after infestation: (a) the last, fifth day, of a first exposure, (b) the second day of a second infestation, (c) the fifth day of a second infestation and (d) fou ... | 1985 | 3913388 |
| epidemiologic aspects of bovine anaplasmosis in semiarid range conditions of south central idaho. | the prevalance of anaplasma marginale-infected cows, as determined by use of the modified rapid card agglutination (mrca) test, was measured during a 4-year period (1980-1983). the prevalence of a marginale-infected cows, defined as positive reactors on the mrca test, remained constant (31%-37%). the apparent incidence of a marginale transmission to susceptible cows was approximately 7% from 1980 to 1981, 8% from 1981 to 1982, and no transmission from 1982 to 1983. the occasional mrca-positive c ... | 1986 | 3963555 |
| acquisition and expression of resistance by bos indicus and bos indicus x bos taurus calves to amblyomma americanum infestation. | purebred and crossbred bos indicus calves were infested 1, 2, or 3 times with 10 female and 5 male amblyomma americanum. resistance was acquired by both the purebred and the crossbred calves after 1 infestation and resulted in statistically significant decreases in the percentages of females that engorged, the mean weights of engorged females, and the mean weights of egg masses. comparisons between breeds of the percent of female ticks that engorged during the first and second infestations indic ... | 1985 | 3998956 |
| discriminant analysis of vegetational and topographical factors associated with the focal distribution of rocky mountain wood ticks, dermacentor andersoni (acari: ixodidae), on cattle range. | | 1985 | 4009628 |
| transmission of anaplasma marginale by adult dermacentor andersoni during feeding on calves. | laboratory-reared dermacentor andersoni ticks experimentally infected as nymphs with anaplasma marginale were allowed to feed as adults from 1 to 9 days on susceptible, splenectomized calves to determine when, during feeding, the hematozoan was transmitted from ticks to cattle. in experiment 1, ticks were allowed to feed on calves for 1, 2, 3, 4, 5, or 6 days and anaplasmosis did not result. the same calves were used for experiment 2, and ticks were allowed to feed for 1, 3, 6, 7, 8, or 9 days a ... | 1985 | 4026042 |
| resistance to ixodid tick infestation induced by administration of tick-tissue culture cells. | primary tissue culture cells of developing larvae of amblyomma americanum were administered to guinea-pigs never previously exposed to ixodid ticks. guinea-pigs were given 1 x 10(6) primary culture cells on days 0, 7 and 21 by subcutaneous injection and challenged with male and female a. americanum on day 35. a significant degree of induced host tick resistance was expressed by reduced engorgement weight of females, reduced oviposition by those females which did obtain a blood meal, and by death ... | 1985 | 4083961 |
| fine structure of rickettsia canada in tissues of dermacentor andersoni stiles. | preliminary observations on growth and developmental fine structure of rickettsia canada in various organs and tissues of the hard tick, dermacentor andersoni stiles, are reported. r. canada is typically rod-shaped, being delimited with a three-layered wall having a velvety coating adsorbed to its exterior surface. a finely reticulated cytoplasmic matrix containing prominent ribosomes is delimited with a three-layered unit membrane. average length and width of these organisms are 1.6 by 0.4 mum. ... | 1971 | 4100833 |
| a proposed site of fluid secretion in the salivary gland of the ixodid tick dermacentor andersoni. | | 1973 | 4127146 |
| recognition of anaplasma marginale theiler in dermacentor andersoni stiles (=d. venustus marx) by the fluorescent antibody method. i. smears of nymphal organs. | | 1970 | 4189907 |
| isolation and characterization of symbiotes from the rocky mountain wood tick, dermacentor andersoni. | | 1973 | 4202564 |
| fine structure of oogonial and oocyte development in dermacentor andersoni stiles (acari: ixodidae). | | 1971 | 4327965 |
| fine structure of normal hemocytes in dermacentor andersoni stiles (acari:ixodidae). | | 1971 | 4332374 |
| creatine phosphokinase elevation in a case of tick paralysis. | the results of studies on a case of tick paralysis in a female child are described. the patient was paralysed by a single female specimen of dermacentor andersoni stiles attached to the left temporal area of the scalp. paralysis of the lower limbs, incoordinate respiration and weakness of the arms were evident.the findings on physical examination and the results of diagnostic laboratory procedures are reported and the possible significance of the results is discussed. the only abnormal laborator ... | 1973 | 4707234 |
| biochemical and physiological studies of certain ticks (ixodoidea). fatty acid composition of the female, eggs, and larva of dermacentor andersoni (stiles) (ixodidae). | | 1973 | 4744042 |
| biochemical and physiological studies of certain ticks (ixodoidea): isolation and partial identification of a new fatty acid in eggs of dermacentor andersoni stiles (ixodidae). | | 1974 | 4837887 |
| localization of powassan virus in dermacentor andersoni ticks by immunofluorescence. | | 1969 | 4905045 |
| sites of attachment of 'prairie' and 'montane' dermacentor andersoni (acarina: ixodidae) on cattle. | | 1972 | 5036197 |
| gross anatomical, histological, and cytological aspects of ovarian development in dermacentor andersoni (stiles (acari: ixodidae). | | 1971 | 5105959 |
| transstadial (nymph-to-adult) infection of anaplasma marginale in dermacentor andersoni stiles. | | 1971 | 5160254 |
| natural history of tick-borne spotted fever in the usa. susceptibility of small mammals to virulent rickettsia rickettsii. | in the ecology of spotted fever rickettsiae, one of the as yet unsolved problems concerns the significance of small animals in the distribution of rickettsia rickettsii in nature. in the bitter root valley of western montana, a great variety of rodents, rabbits and hares are known to serve as the preferred hosts for the immature stages of the vector tick, dermacentor andersoni.the authors analyse the susceptibility of various species of small mammals to virulent r. rickettsii and evaluate their ... | 1966 | 5296999 |
| ecology of tick vectors of american spotted fever. | the author reviews the natural history of the tick vectors of american spotted fever. the discussion concerns the ecology of the rocky mountain wood tick, dermacentor andersoni, the american dog tick, dermacentor variabilis, and the lone-star tick, amblyomma americanum, all of which are proven vectors of rocky mountain spotted fever to man. also included are the rabbit tick, haemaphysalis leporispalustris and dermacentor parumapertus, which very rarely bite man but which are considered of import ... | 1969 | 5306621 |
| anaplasmosis. xix. a preliminary study of anaplasma marginale in dermacentor andersoni (stiles) by fluorescent antibody technique. | | 1966 | 5335865 |
| attempts to transmit bovine anaplasmosis with anopheles quadrimaculatus say (diptera: culicidae) and dermacentor andersoni stiles (acarina: ixodidae). | | 1970 | 5485390 |
| occurrence of colorado tick fever virus in dermacentor andersoni ticks in british columbia. | | 1968 | 5667781 |
| effects of vitamin a deficiency and ked resistance on the feeding of dermacentor andersoni on sheep. | | 1968 | 5690045 |
| phenology, behavior, and host-relations of dermacentor andersoni stiles in outdoor "rodentaria" and in nature. | | 1968 | 5749472 |
| collection of dermacentor andersoni (stiles) with carbon dioxide and its application in studies of colorado tick fever virus. | | 1965 | 5841585 |
| growth of colorado tick fever (ctf) virus in primary tissue cultures of its vector, dermacentor andersoni stiles (acarina: ixodidae), with notes on tick tissue culture. | | 1967 | 6073593 |
| staining characteristics of colonies of anaplasma marginale theiler in dermacentor andersoni stiles. | colonies of anaplasma marginale theiler were studied in midgut epithelial cells of adult dermacentor andersoni stiles that were infected as nymphs. the colonies were demonstrated in plastic sections (1 micrometer) and frozen sections (6 micrometer) with mallory's stain. colonies were also demonstrated in frozen sections, using direct fluorescent antibody technique. colonies were not observed in plastic or frozen sections stained by the giménez method. in all preparations, the colonies were usual ... | 1981 | 6175257 |
| significant changes in epidermal langerhans cells of guinea-pigs infested with ticks (dermacentor andersoni). | resistance to tick feeding has previously been shown to be an acquired, immunologically mediated phenomenon in guinea-pigs, associated with cutaneous basophil hypersensitivity to tick antigens. in this study, langerhans cells (lc) in the epidermis of guinea-pigs were monitored during tick infestations of susceptible and resistant animals. a specific adenosine triphosphatase (atpase) staining technique was used to identify epidermal lc. the numbers of lc decreased significantly around the sites o ... | 1984 | 6228517 |
| the ecology of colorado tick fever in rocky mountain national park in 1974. ii. infection in small mammals. | field studies of colorado tick fever (ctf) in small mammals in rocky mountain national park (rmnp) in 1974 established that eutamias minimus and spermophilus lateralis were the most important hosts for ctf virus and were the source of virus for immature stages of the tick vector, dermacentor andersoni. other species (peromyscus maniculatus, spermophilus richardsonii, eutamias umbrinus) are secondary hosts. the intensity of viral activity in rodents varied greatly from locality to locality. highe ... | 1981 | 6263122 |
| immunocytochemical labeling of anaplasma marginale theiler in dermacentor andersoni stiles with peroxidase- antiperoxidase technique. | colonies of anaplasma marginale in midgut epithelial cells of adult ticks that had been infected as nymphs were specifically labeled, using the unlabeled antibody peroxidase-antiperoxidase method of immunocytochemistry. visual comparison of infected and control tissue sections with the electron microscope demonstrated deposition of ring-like peroxidase-antiperoxidase complexes over organisms within the colonies. the intensity of labeling differed among organisms within a single colony, possibly ... | 1982 | 6285774 |
| demonstration of anaplasma marginale in hemolymph of dermacentor andersoni by animal inoculation and by fluorescent-antibody technique. | hemolymph was collected from adult dermacentor andersoni stiles that had been infected with anaplasma marginale theiler as nymphs. before hemolymph was collected, the adult ticks were either incubated and unfed at 37 c for 2.5 days or fed for 6 days on sheep. hemolymph collected from groups of 100 ticks was inoculated into susceptible splenectomized calves. smears of hemolymph from the same groups of ticks were prepared for examination by fluorescent antibody technique. hemolymph from incubated ... | 1983 | 6346968 |
| biochemical and immunochemical analysis of rickettsia rickettsii strains of various degrees of virulence. | six strains of rickettsia rickettsii from montana and north carolina were examined in an effort to identify rickettsial constituents associated with virulence. fever responses, scrotal reactions, and mortalities of male guinea pigs inoculated intraperitoneally with 1,000 pfu of rickettsial strains revealed that the two montana patient strains ( sheila smith and norgaard ) and one montana strain ( sawtooth female 2) from the wood tick, dermacentor andersoni, could be placed in the group of highes ... | 1984 | 6427110 |
| demonstration of the inclusion appendage of anaplasma marginale in nymphal dermacentor andersoni. | dermacentor andersoni nymphs were placed in stockinettes and allowed to feed on a splenectomized calf with experimentally induced anaplasmosis when the parasitemia was 3%-5%. nymphs were selected on each of the 6 days of feeding and every 5 days from repletion through molting to the adult stage (25 days postrepletion); they were killed and midgut tissues were processed and examined by light and electron microscopies. no stages of a marginale were seen in tissues of feeding ticks. visualization o ... | 1984 | 6497136 |
| some aspects of organic acid metabolism in dermacentor andersoni female. | | 1984 | 6512290 |
| development of colonies of anaplasma marginale in the gut of incubated dermacentor andersoni. | | 1983 | 6625314 |
| radiorespirometric determination of contribution of pentose phosphate cycle to metabolism of glucose in dermacentor andersoni. | | 1983 | 6631086 |
| demonstration of colonies of anaplasma marginale in the midgut of rhipicephalus simus. | rhipicephalus simus nymphs were allowed to feed on a cow experimentally infected with the bw-strain of anaplasma marginale from republic of south africa, and they were studied as adults. colonies were demonstrated by light microscopy in midgut epithelial cells of adult ticks that were unfed (as adults), incubated, or prefed for 72 hours on a cow. the colonies occurred in 5 different morphologic types (1 to 5) that were similar to those described previously for a virginia isolate of a marginale i ... | 1983 | 6660614 |
| tularaemia transmitted by ticks (dermacentor andersoni) in saskatchewan. | common wood ticks (dermacentor andersoni) collected from saskatchewan landing provincial park, saskatchewan in the spring of 1982 transmitted a lethal tularaemia infection to four of six rabbits. francisella tularensis organisms were isolated from tissues taken from the dead rabbits and identified from subcultures using an indirect immunofluorescent antibody assay. one human associated with the animals developed symptoms of tularaemia and, after successful therapy, had a significant increase in ... | 1983 | 6667429 |
| pheromone-induced aggregation of ixodid ticks before host contact. | the presence of a pre-feeding aggregation pheromone was demonstrated in the species dermacentor variabilis, dermacentor andersoni, dermacentor parumapertus, amblyomma americanum and haemaphysalis leporispalustris by assay within a petri dish. however, amblyomma maculatum and amblyomma cajennense did not aggregate in the sector containing discs of presumed pheromone within the hour period. d. andersoni and a. americanum recognized each other's pheromone and a. americanum recognized that of h. lep ... | 1983 | 6683667 |
| serotypes of spotted fever group rickettsiae isolated from dermacentor andersoni (stiles) ticks in western montana. | adult dermacentor andersoni ticks were collected by flagging vegetation in 18 canyons bordering the bitterroot valley, montana, an area where nearly 400 cases of rocky mountain spotted fever (rmsf) have occurred since 1900. three hundred and nine (8.3%) of the 3,705 ticks collected contained hemocyte-associated rickettsia-like organisms of three morphologic types, coccobacillary, fine bacillary, and coarse bacillary (long forms). only the coccobacillary and fine bacillary organisms stained with ... | 1981 | 6782899 |