Publications

identification and characterization of anticoagulant activities in the saliva of the lone star tick, amblyomma americanum (l.).	anticoagulant activities against both the extrinsic and intrinsic coagulation pathways were identified in the saliva of partially fed female lone star ticks, amblyomma americanum (l.). the activities of factor xa and thrombin in the common pathway of the coagulation cascade were inhibited by tick saliva. the greatest anticoagulant activities were found in the saliva of ticks weighing more than 200 mg. the anticoagulant activities in tick saliva could be detected without preincubation of tick sal ...	1997	9057694
tick-raccoon associations and the potential for lyme disease spirochete transmission in the coastal plain of north carolina.	raccoons (procyon lotor) were live-trapped and examined for ticks from july 1990 to july 1993 in the coastal plain of north carolina on marine corps base, camp lejeune, north carolina (usa). five species of ixodid ticks were found on 351 (78%) of 449 raccoons. amblyomma americanum was the most abundant tick found on raccoons. dermacentor variabilis, ixodes texanus, and ixodes scapularis were frequently collected, while ixodes cookei were rarely collected from raccoons. tick burdens were not affe ...	1997	9027688
cloning and sequence of a gene for a homologue of the c subunit of the v-atpase from the salivary gland of the tick amblyomma americanum (l).	a 1084 base pair partial cdna showing similarity to the c subunit of the vacuolar atpase (v-atpase) was isolated on a clone from a cdna library made from salivary glands from 3-day-old feeding adult amblyomma americanum (l.) female ticks. the 5' end was completed using primer extension and the two pieces joined to form a complete cdna of 1373 bp. this mrna is expressed in embryos and the salivary glands of unfed adults and adult females at all stages of feeding. specific inhibitors of the v-atpa ...	1997	9013257
human ehrlichiosis--maryland, 1994.	ehrlichiosis is an emerging tickborne infectious disease caused by obligate intracellular, gram-negative rickettsia that infect leukocytes. human monocytic ehrlichiosis (hme) is caused by ehrlichia chaffeensis and is believed to be transmitted by amblyomma americanum (the lone star tick). most hme cases have been reported in southeastern and south-central states. during may-july 1994, five cases of serologically confirmed hme were identified among residents of maryland. all five persons lived ne ...	1996	8926996
tick avoidance behaviors associated with a decreased risk of anti-tick salivary gland protein antibody seropositivity in military personnel exposed to amblyomma americanum in arkansas.	during april through september 1990, 399 military personnel who originated from either fort chaffee, arkansas (n = 236) or fort wainwright, alaska (n = 163) were studied during maneuvers in tick-infested areas at fort chaffee. study subjects completed a questionnaire and had pre- and post-maneuvers serum specimens analyzed for antibodies to several rickettsial and ehrlichial agents and to amblyomma americanum (lone star tick) salivary gland proteins (anti-tick saliva antibodies [atsa], a biologi ...	1996	8916798
site-specific geographic association between amblyomma americanum (acari: ixodidae) infestations and ehrlichia chaffeensis-reactive (rickettsiales: ehrlichieae) antibodies in white-tailed deer.	serum samples from white-tailed deer, odocoileus virginianus zimmermann, collected from 1982 through 1992 from the southeastern united states were tested for antibodies reactive to ehrlichia chaffeensis anderson, dawson, jones, & wilson, the causative agent of human ehrlichiosis. results were compared between areas based on known infestations of the lone star tick, amblyomma americanum l., a suspected vector of e. chaffeensis. one hundred and twenty-five of 300 (41.7%) deer tested positive (> or ...	1996	8906920
seasonal activity and relative abundance of amblyomma americanum in mississippi.	ecological investigations of the lone star tick, amblyomma americanum (l.), were conducted in 3 adjacent 60-m2 plots, located in noxubee national wildlife refuge, noxubee county, mississippi. ticks were collected weekly from july 1992 to july 1993 by flagging randomly selected lanes. during the year, larval ticks were collected first in early july, with peak numbers in september, and they were collected no later than late october. nymphal ticks were collected from mid-march to late october, with ...	1996	8906916
survival and water-balance characteristics of unfed adult amblyomma cajennense (acari: ixodidae).	off-host survival, water balance, and cold tolerance of unfed adult, cayenne ticks, amblyomma cajennense (f.), were examined to evaluate species characteristics important to zoogeography and off-host ecology. survivorship decreased when males and females were subjected to progressively drier constant environmental conditions. average maximum survival was 641.2 and 682.5 d at 85% rh and 23 degrees c (2.98 mm hg) for males and females, respectively. mean survival in both sexes was progressively le ...	1996	8906907
effects of pyriproxyfen on engorged females and newly oviposited eggs of the lone star tick (acari:ixodidae).	engorged females and 1- to 3-d-old eggs of the lone star tick, amblyomma americanum (l), were exposed to 9 treatments of pyriproxyfen (4, 8, and 16 micrograms/cm2) in glass vials at exposure periods of 7 d, 14 d, and continuous at each dosage level. treatment of newly engorged females did not affect the number of females ovipositing, but the number of eggs oviposited decreased as dosage and exposure time increased. complete inhibition of egg hatch occurred at all treatment levels except that of ...	1996	8840677
a self-medicating applicator for control of ticks on deer.	a self-medicating applicator for killing ticks on deer and domestic ungulates by passive transfer of acaricides during feeding is described. the applicator consists of a barrel divided into a food bin (above) and a sealed self-contained acaricide reservoir (below) with a vertical, centrally-located ceramic column that extends from the reservoir into the food bin. acaricide is drawn up the column from the sealed reservoir by absorption. animals attracted to the food in the device acquire the acar ...	1996	8744707
cold-hardiness of a laboratory colony of lone star ticks (acari: ixodidae).	the cold-hardiness of a lone star tick, amblyomma americanum (l.), laboratory colony was characterized. fed and unfed larvae, fed and unfed nymphs, and unfed adults did not survive exposure to -17 degrees c for 7 d. after an 8-d exposure to -10 degrees c, adults tolerated cold better than immatures and unfed specimens fared better than fed ticks. exposing unfed 6-wk-old (postmolt) adult males and females to -15 degrees c for increasing intervals up to 2 h suggests that males were more tolerant t ...	1996	8699473
salivary gland changes and host antibody responses associated with feeding of male lone star ticks (acari:ixodidae).	the goal of this study was to demonstrate that male lone star ticks, amblyomma americanum (l.), actively feed on rabbits during attachment and that the host is capable of mounting an immune response against male salivary gland proteins. during attachment, it was shown that male ticks salivary glands hypertrophy. an enzyme-linked immunosorbent assay was used to detect rabbit serum proteins in the midgut of previously attached male ticks. sds-polyacrylamide gel electrophoresis showed that the prot ...	1996	8699458
molecular cloning of delta 9 fatty acid desaturase from the protozoan tetrahymena thermophila and its mrna expression during thermal membrane adaptation.	in response to a decrease in its growth temperature, the protozoan tetrahymena is known to increase the level of unsaturated fatty acids in its membrane phospholipids so as to maintain the correct physical state (fluidity) of the membranes. in this organism, synthesis of unsaturated fatty acids is initiated by delta 9 acyl-coa desaturase. our previous studies have shown that, during cold adaptation, the activity of microsomal palmitoyl- and stearoyl-coa desaturase increases, reaching a maximal l ...	1996	8694777
systemic treatment of white-tailed deer with ivermectin-medicated bait to control free-living populations of lone star ticks (acari:ixodidae).	whole-kernel corn was treated with 10 mg ivermectin per 0.45 kg corn and fed at rate of approximately .45 kg/deer per day to white-tailed deer confined in the treatment pasture, whereas deer in an adjacent control pasture received a similar ration of untreated corn. treatments were dispensed from february through september of 1992 and 1993, and free-living populations of lone star ticks. amblyomma americanum (l.), were monitored in both pastures using dry-ice traps to quantify nymphs and adults ...	1996	8667385
ticks parasitizing humans in georgia and south carolina.	from 1990 through 1995, 913 ticks removed from 460 human patients in georgia or south carolina were identified and recorded. the majority of these specimens (758, 83.0%) were lone star ticks, amblyomma americanum. one hundred and four (11.4%) american dog ticks dermacentor variabilis, 36 (3.9%) blacklegged ticks ixodes scapularis, 9 (1.0%) gulf coast ticks amblyomma maculatum, and 6 (0.7%) brown dog ticks rhipicephalus sanguineus were also recovered. all active stages (larvae, nymphs, and adults ...	1996	8636862
ehrlichia-like 16s rdna sequence from wild white-tailed deer (odocoileus virginianus).	the reservoir hosts of ehrlichia chaffeensis, etiologic agent of human ehrlichiosis are unknown. initially, white-tailed deer (wtd) were serologically implicated as possible reservoirs of e. chaffeensis. subsequent studies showed that wtd were susceptible to infection with e. chaffeensis and that deer-to-deer transmission by a tick vector, amblyomma americanum, is possible under experimental conditions. to determine if wild wtd were infected with e. chaffeensis, whole blood was collected from 10 ...	1996	8627501
dietary modification of host blood lipids affect reproduction in the lone star tick, amblyomma americanum(l.).	the feeding and reproductive performance of female lone star ticks (amblyomma americanum (l.)) infesting guinea pigs on diets containing 15% fish oil (fo) or safflower oil (so) were investigated. replete ticks fed on fo-fed guinea pigs weighed approximately 30% less than those on the so-fed guinea pigs. the lower engorged weight resulted in a similar decrease in the mass and number of eggs laid and number of larvae hatching. no effect of host dietary treatment was observed upon the reproductive ...	1996	8604084
ixodid ticks from panthers and bobcats in florida.	ixodid ticks were present in all 189 samples examined from 53 florida panthers (felis concolor coryi, 104 collections) and 85 bobcats (felis rufus floridana) in florida (usa) between 1974 and 1991. we identified 3,251 ticks from panthers and 918 from bobcats. specimens of dermacentor variabilis, ixodes scapularis, i. affinis, amblyomma maculatum, and a. americanum were present on 49, 39, 17, seven, and two of the 53 florida panthers, respectively, and comprised 36%, 55%, 7%, 1%, and < 1% of the ...	1995	8592378
temporal association of amblyomma americanum with the presence of ehrlichia chaffeensis reactive antibodies in white-tailed deer.	from 1981 through 1993, tick infestations and serum antibodies reactive to ehrlichia chaffeensis, the causative agent of human ehrlichiosis, were monitored among white-tailed deer (odocoileus virginianus) at whitehall experimental forest, clarke county, georgia (usa). neither ticks nor e. chaffeensis antibodies were detected during the first two years of the study. infestations of the lone star tick (amblyomma americanum), a suspected vector of e. chaffeensis, first were noted on deer in 1983. p ...	1995	8583627
identification of an uncultivable borrelia species in the hard tick amblyomma americanum: possible agent of a lyme disease-like illness.	bites from the hard tick amblyomma americanum are associated with a lyme disease-like illness in the southern united states. to identify possible etiologic agents for this disorder, a. americanum ticks were collected in missouri, texas, new jersey, and new york and examined microscopically. uncultivable spirochetes were present in approximately 2% of the ticks. borrelia genus-specific oligonucleotides for the flagellin and 16s rrna genes were used for amplification of dna. products were obtained ...	1996	8568302
hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr.	ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ...	1995	8567911
serologic diagnosis of human monocytic ehrlichiosis by immunoblot analysis.	human monocytic ehrlichiosis is caused by ehrlichia chaffeensis, an intracellular bacterium probably transmitted by the tick amblyomma americanum in the united states. despite its lack of specificity in discriminating among infections by closely related ehrlichia spp., immunofluorescence assay (ifa) is the most frequently used serological diagnostic method. to improve the specificity of the serological diagnosis, we compared antigenic profile of e. canis and e. chaffeensis antigen with homologou ...	1994	8556515
field evaluation of deet and a piperidine repellent (ai3-37220) against amblyomma americanum (acari: ixodidae).	repellent efficacy of deet (n,n-diethyl-3-methylbenzamide) and a piperidine, ai3-37220, was evaluated topically on human volunteers against lone star tick, amblyomma americanum (l.), nymphs and adults in the field. ai3-37220, at 0.5 mg/cm2, provided > 90% repellency against adult and nymphal ticks over a 6-h test period and showed significantly better repellent efficacy than deet. deet, at the same concentration, provided 85% repellency at 0 h and deteriorated to 55% repellency at 6 h.	1995	8551512
prostaglandin biosynthesis and subcellular localization of prostaglandin h synthase activity in the lone star tick, amblyomma americanum.	we report on prostaglandin (pg) biosynthesis in the lone star tick, amblyomma americanum. in vitro preparations of whole female ticks and internal tissues were competent to biosynthesize four pgs: pga2/pgb2, pgd2, pge2, pgf2 alpha. pga2/pgb2 was the major product under optimal conditions. pg biosynthesis by whole tick and internal tissues were sensitive to incubation conditions including, protein concentration, time, temperature, ph, and presence of a co-factor cocktail composed of reduced gluta ...	1995	8541884
alteration of arachidonate levels in tick salivary glands by dietary modification of host blood lipids.	tick saliva contains prostaglandins of the 2-series, believed to facilitate bloodmeal acquisition. because ticks cannot synthesize the prostaglandin precursor, arachidonic acid, investigations were undertaken to study the uptake, incorporation, and distribution of arachidonic acid in the salivary glands of the lone star tick in vitro and in vivo. uptake of [3h]arachidonate by isolated salivary glands was reduced in the presence of low concentrations of arachidonic or eicosapentaenoic acids, but ...	1996	8541571
physiological and nutritional responses of steers infested with varying densities of amblyomma americanum (acari: ixodidae).	the effects of varying densities of lone star tick, amblyomma americanum (l.), on measured physiological parameters of beef cattle in a controlled environment was determined. steers were infested with either 0, 20, 60, or 120 pairs of adult ticks. heart rate, respiration, rectal temperature, fecal and urine excretions, and water and feed consumption were monitored daily. blood samples were taken every 3rd d to measure cortisol, total proteins, urea nitrogen, and glucose levels. hematocrits were ...	1995	8537543
a new borrelia infecting lone star ticks.		1996	8531586
computer-controlled olfactometer system for studying behavioral responses of ticks to carbon dioxide.	an olfactometer system that consisted of a laptop computer, a carbon dioxide analyzer, and an apparatus to control gas flows was designed to study ixodid tick behavioral responses to varying carbon dioxide (co2) concentrations. the system provided a method to regulate and measure stimulatory co2 concentrations (1-99 ppm) above ambient co2 background levels. adult amblyomma americanum (l.) and dermacentor variabilis (say) demonstrated behavioral responses to co2 concentrations as low as 9 ppm abo ...	1993	8510116
implications of selection and hybridization studies on the mode of inheritance of photoperiodically induced developmental diapause in laboratory strains of the lone star tick (acari: ixodidae).	selection of lone star ticks, amblyomma americanum (l.), that were reared in the laboratory under short-day photoperiods of 10:14 (l:d) h resulted in third generation (f3) diapause versus f3 nondiapause strain replete nymphs having significantly different mean molting times (days from detachment to ecdysis) of 100.9 versus 54.7 d, respectively; whereas, the f7 unselected laboratory control strain had an even smaller, significantly different mean molting time of 49.5 d. two hybrid crosses of f2 n ...	1993	8433316
amblyomma americanum: a potential vector of human ehrlichiosis.	polymerase chain reaction primers specific for ehrlichia chaffeensis were used to amplify dna from extracts of pooled ticks. amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. the characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. no specific product was observed after amp ...	1993	8357086
isolation and transmission of the lyme disease spirochete from the southeastern united states.	the isolation of the lyme disease spirochete (borrelia burgdorferi) from the southeastern united states is reported. three isolates, two from cotton mice (peromyscus gossypinus) and one from the black-legged tick (ixodes scapularis), were recovered from sapelo island, georgia, in july and september 1991. the spirochetes were characterized by indirect fluorescent antibody assay using a battery of five monoclonal antibodies, by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (sds/page) o ...	1993	8346258
analysis of lipids in the salivary glands of amblyomma americanum (l.): detection of a high level of arachidonic acid.	analysis of lipids in salivary glands of the lone star tick, amblyomma americanum, demonstrated that arachidonic acid (20:4, n-6) comprises 8% of all fatty acids identified by gas chromatography. the occurrence of arachidonic acid and other c20 polyunsaturated fatty acids in tick salivary glands was confirmed by gas chromatography-mass spectrometry. arachidonate is located entirely in the phospholipid fraction and is associated exclusively with phosphatidylcholine (pc) and phosphatidylethanolami ...	1993	8324244
changes in lipids of the salivary glands of the lone star tick, amblyomma americanum, during feeding.	the lipid composition of salivary glands from male and female lone star ticks, amblyomma americanum, was investigated at progressive stages of tick feeding. the amounts of fatty acids from both phospholipid and neutral lipid fractions increased dramatically during the initial stage of feeding and peaked in partially fed females weighing 100-250 mg. percentage compositions of myristic (14:0) and palmitic acid (16:0) decreased, but stearic (18:0), oleic (18:1), linoleic (18:2), and arachidonic aci ...	1993	8277375
ticks (acari: ixodidae) infesting medium-sized wild mammals in southwestern tennessee.	seven species of ixodid ticks (n = 2,661) were found on medium-sized wild mammals (n = 295) during a 13-mo study in shelby county, tennessee. the seven tick species collected were dermacentor variabilis (say), amblyomma americanum (l.), rhipicephalus sanguineus (latreille), ixodes texanus (banks), i. cookei (packard), i. scapularis (say), and haemaphysalis leporispalustris (packard). the raccoon had the greatest tick species diversity in all of the aforementioned ticks except h. leporispalustris ...	1993	8254637
new version of lstsim for computer simulation of amblyomma americanum (acari: ixodidae) population dynamics.	a previous version of lone star tick simulation model (lstsim) for a wildlife ecosystem was revised and expanded to include a beef cattle forage area and improved handling of tick-host-habitat interactions. relationships between environmental and biological variables were also refined in the new version. general validity of the revised model was established by comparing simulated and observed host-seeking populations of amblyomma americanum (l.) at five geographic locations, three in oklahoma an ...	1993	8254630
prevalence of borrelia (spirochaetaceae) spirochetes in texas ticks.	between 1990 and 1992, ticks from eight texas parks were collected and analyzed to determine the prevalence of spirochete-infected ticks. borrelia spirochetes were detected in 1.03% of 5,141 amblyomma americanum (l.) adults examined, a species texas residents often encounter. no spirochetes were observed in the other tick species tested.	1994	8189421
influence of annual and biennial prescribed burning during march on the abundance of amblyomma americanum (acari: ixodidae) in central georgia.	a 5-yr study to evaluate the influence of annual and biennial prescribed burning in march on the abundance of amblyomma americanum (l.) was conducted on oconee wildlife management area in the piedmont physiographic region of georgia. tick abundance on plots embedded in larger burned and unburned areas were monitored with cloth drags and co2-baited cloth panels monthly during march through september from 1987 through 1991. annual and biennial prescribed burning from 1988 to 1991 significantly red ...	1994	8158633
seasonal and annual abundance of amblyomma americanum (acari: ixodidae) in central georgia.	seasonal and annual changes in the abundance of amblyomma americanum (l.) larvae, nymphs, and adults were monitored over a 5-yr period in the piedmont physiographic region of georgia. tick abundance was monitored with cloth drags (all life stages) and co2-baited cloth panels (nymphs and adults) monthly during march through september from 1987 through 1991. larvae appeared in substantial numbers in july and were most numerous in august and september. small numbers of unfed larvae apparently overw ...	1994	8158632
genome size and organization in the ixodid tick amblyomma americanum (l.).	we used dna reassociation kinetics to determine genome size and organization in the ixodid tick amblyomma americanum. we calculated the genome size of a. americanum to be approximately 1.08 pg or 1.04 x 10(9) base pairs and to consist of 35.8% unique dna, 4.2% foldback sequences, 17.9% highly repetitive sequences, and 42.1% moderately repetitive sequences. comparison of the reassociation kinetics of long and short fragments revealed repetitive sequences to be distributed in a pattern of long per ...	1994	8069417
distribution of arachidonic acid among phospholipid subclasses of lone star tick salivary glands.	the subclass composition of choline- and ethanolamine-containing phospholipids was determined by analysis of acyl-linked fatty acids released by base hydrolysis of diradylglycerobenzoates formed from lone star tick salivary gland diacyl, alkylacyl and alkenylacyl phospholipids. the diacyl subclass comprises 87% of all choline-containing phospholipids, while th alkylacyl subclass comprises c. 9% and the alkenylacyl subclass c. 4%. the diacyl subclass comprises 72-77% of ethanolamine-containing ph ...	1994	8069331
ticks (acari: ixodidae) collected from small and medium-sized kansas mammals.	seven species of hard-bodied ticks were collected from 20 species of small and medium-sized mammals in kansas; amblyomma americanum l., dermacentor variabilis (say), haemaphysalis leporispalustris (packard), ixodes cookei packard, i. kingi bishopp, i. sculptus neumann, and i. texanus banks. dermacentor variabilis was found statewide, a. americanum only in the eastern one-third of the state, and the ixodes spp. and h. leporispalustris were widely scattered. the most common tick found was d. varia ...	1994	8057327
origin, accumulation and mobilization of salivary prostaglandin precursors in the lone star tick.		1994	7958372
evidence supporting the presence of borrelia burgdorferi in missouri.	although lyme disease is commonly seen in the southcentral united states, the epidemiology of the disease is poorly defined there. the purpose of this study was to document the presence of borrelia burgdorferi in ticks collected in southeastern missouri and around the city of st. louis. spirochetes were detected and identified as b. burgdorferi by immunofluorescent antibody (ifa) tests using the monoclonal antibody h5332 in 1.9% of amblyomma americanum and 2.0% of dermacentor variabilis ticks co ...	1994	7943575
integrated management strategies for amblyomma americanum (acari: ixodidae) on pastured beef cattle.	data on tick control and knowledge of the damage caused to beef cattle by tick feeding were incorporated into a computerized dynamic life table model (lstsim) for amblyomma americanum (l.). simulations were made to determine economically feasible, 5-yr integrated pest management (ipm) strategies for a. americanum in forage areas utilized by bos taurus, bos indicus, and crossbred cattle (b. taurus x b. indicus). the effects of host resistance, pasture rotation, habitat conversion, topical acarici ...	1994	7932604
cytosystematics of five north american amblyomma (acarina: ixodidae) species.	the karyotypes of 5 species of amblyomma ticks found in north america were examined for the presence and location of constitutive heterochromatin (c-bands). all specimens examined had 20 autosomes and an xx:xo sex-determining system, with the x being the largest element in the karyotype. except as noted in text, the autosomes of all species were acrocentric and heterochromatin was restricted to the centromeric region. the third largest autosome in 4 of the 5 species displayed a consistent band o ...	1995	7876973
ectoparasites of opossums and raccoons in southeastern georgia.	twelve species of ectoparasites (four fleas, three ticks, three chiggers, one macronyssid mite, and one atopomelid mite) were recovered from 42 opossums, didelphis virginiana kerr, live-trapped from september 1992 through april 1994 in southeastern georgia. the fleas, ctenocephalides felis (bouché) (prevalence = 19%) and polygenis gwyni (c. fox) (36%); the ticks, dermacentor variabilis (say) (40%) and ixodes scapularis say (19%); and the macronyssid mite, ornithonyssus wernecki (fonseca) (21%), ...	1994	7815408
uptake, incorporation and redistribution of arachidonic acid in isolated salivary glands of the lone star tick.	the ability of isolated salivary glands from the lone star tick, amblyomma americanum, to take up, incorporate and redistribute [3h]arachidonic acid was examined. uptake of arachidonic acid was concentration dependent--a single salivary gland incorporated up to approximately 2.8 micrograms arachidonic acid in 60 min. over 90% of the [3h]arachidonate entering the glands was esterified and found only in the phospholipid (approximately 80%) and triglyceride (approximately 10%). essentially no radio ...	1995	7742831
origin of arachidonic acid in the salivary glands of the lone star tick, amblyomma, americanum.	the contribution of synthesis and dietary sequestration to the high arachidonate content of the lone star tick, amblyomma americanum, salivary glands was investigated by assessing the salivary metabolites of various radiolabeled fatty acid substrates administered to partially fed females. a portion of each of the fatty acids studied was incorporated into the fatty acid moiety of the phospholipid fraction. [14c]acetate was metabolized only into myristic, palmitic, palmitoleic, steric, and oleic a ...	1995	7711753
borrelia burgdorferi in eastern virginia: comparison between a coastal and inland locality.	in virginia, borrelia burgdorferi was more prevalent in a site along the atlantic ocean, near maryland, than in an inland site near williamsburg and yorktown. at the coastal site on assateague island, b. burgdorferi was isolated from 4.2% of 475 animals sampled, including four species of small mammals. serologic tests indicated that 25-37% of the small rodents assayed had been exposed to b. burgdorferi. immunofluorescence antibody assays specific for b. burgdorferi showed spirochete infection in ...	1995	7677212
regulation of free arachidonic acid levels in isolated salivary glands from the lone star tick: a role for dopamine.	an important regulatory step for prostaglandin synthesis is the availability of the precursor, free arachidonic acid (aa). in isolated salivary glands of the lone star tick, amblyomma americanum (l.), the level of free aa appears to depend on higher phospholipase a2 (pla2) activity rather than decreased rates of re-esterification by lysophosphatide acyl transferase (lat). this conclusion is supported by experiments where inhibition of lat with merthiolate was without effect, while the calcium io ...	1995	7655056
lower temperature limits for activity of several ixodid ticks (acari: ixodidae): effects of body size and rate of temperature change.	uncoordinated activity threshold temperature, the temperature below which ticks can no longer seek a host in a coordinated manner, and the activity threshold temperature, when all activity ceases, were examined for three species of ticks found in coastal sections of new york. the mean uncoordinated activity threshold and activity threshold temperatures were determined for nymphal, female and male ixodes scapularis say, nymphal, female, and male amblyomma americanum (l.), and for female and male ...	1995	7650705
evaluation of ixodes scapularis, amblyomma americanum, and dermacentor variabilis (acari: ixodidae) from georgia as vectors of a florida strain of the lyme disease spirochete, borrelia burgdorferi.	the ability of three common tick species from georgia to maintain and transmit the causative agent of lyme disease, borrelia burgdorferi, was compared under laboratory conditions. a b. burgdorferi cotton rat isolate (mi-6) from florida was selected as a strain from the south, and the sh2-82 isolate from new york was used as a positive control. amblyomma americanum (l.) and dermacentor variabilis (say) did not transmit the mi-6 isolate from inoculated hamsters to naive laboratory mice, and nympha ...	1995	7650697
biosynthesis of salivary prostaglandins in the lone star tick, amblyomma americanum.	dopamine-induced saliva from ticks fed [3h]arachidonic acid contained the radiolabelled prostaglandins e2, f2 alpha, d2, and b2, the latter probably derived from pge2 owing to the alkalinity of tick saliva. prostaglandin synthetase (pgs) activity in the salivary gland homogenate from the lone star tick, amblyomma americanum, could not be detected by standard radiometric methodologies successfully employed for tissues from many animal species, including numerous arthropods. modifications to the a ...	1995	7627205
epidemiologic and diagnostic studies of patients with suspected early lyme disease, missouri, 1990-1993.	a retrospective case-control study investigated 45 missouri outpatients with annular rashes meeting a surveillance case definition for erythema migrans and with onset in 1990-1991. risk factors included being male, living near a body of water, and hunting. twenty patients (44%) associated their rash with the bite of a tick; of these, 5 described an adult amblyomma americanum. a typical rash was described as expanding over time and measuring 8 cm in diameter at 4 days after onset. mild constituti ...	1995	7622891
ehrlichiosis in a golf-oriented retirement community.	ehrlichiosis due to ehrlichia chaffeensis usually occurs sporadically or in small clusters, with an annual incidence estimated at 3 to 5 cases per 100,000 population in areas of endemic disease. the putative principal vector is the lone star tick (amblyomma americanum). we investigated an outbreak of ehrlichiosis that occurred in june 1993 among members of a golf-oriented retirement community (community a) in tennessee. the community is densely wooded and borders a wildlife-management area where ...	1995	7616991
experimental transmission of ehrlichia chaffeensis (rickettsiales: ehrlichieae) among white-tailed deer by amblyomma americanum (acari: ixodidae).	ehrlichia chaffeensis anderson, dawson & wilson, causative agent of human (predominantly monocytic) ehrlichiosis, was successfully transmitted experimentally by amblyomma americanum (l.) to white-tailed deer, odocoileus virginianus (zimmerman). deer were needle-exposed intravenously to e. chaffeensis in tissue-culture canine macrophage (dh82) cells, and 11 d later were exposed to laboratory-reared a. americanum larvae, nymphs, and adults for acquisition feeding. three months after this feeding, ...	1995	7616529
activity of repellents applied to skin for protection against amblyomma americanum and ixodes scapularis ticks (acari: ixodidae).	twenty-nine repellents were tested on human skin for duration of activity as protectants against nymphal lone star ticks (amblyomma americanum) and against black-legged or deer ticks (ixodes scapularis say). eleven of these repellents, including deet, provided > 2 h of protection against the lone star tick. one repellent, 1-(3-cyclohexenyl-ylcarbonyl) piperidine, was effective > or = 4 h. four repellents (2 pyridines and 2 piperidines with protection lasting 2.3-3 h) showed acaricidal activity t ...	1995	7616181
ectoparasites collected from bobwhite quail in the southeastern united states.	twenty-one species of ectoparasites representing 19 genera were collected from 481 bobwhite quail (colinus virginianus) from nine areas in four southeastern states. sixteen species, amblyomma americanum, haemaphysalis chordeilis, haemaphysalis leporispalustris, eutrombicula alfreddugesi alfreddugesi, neoschoengastia americana, boydaia colini, pterolichus sp., colinophilus wilsoni, megninia sp., apionacarus wilsoni, colinoptes cubanensis, menacanthus pricei, colinicola numidiana, gonoides ortygis ...	1980	7463603
fecundity and development of the lone star tick on woodlot-pastured braford and hereford heifers.		1980	7430489
experimental transmission of african swine fever virus by ornithodoros coriaceus, an argasid tick indigenous to the united states.	three ticks, indigenous to the united states, were assessed for their ability to maintain and transmit african swine fever virus (asfv). amblyomma americanum and a cajennense adults and nymphs maintained virus for 4 to 7 days after engorging on infected swine blood; however, virus was not carried through the subsequent molt of nymphs and it was not transmitted vertically to the eggs and larvae of the infected females. on refeeding of the ticks, infection was not transmitted to healthy swine. orn ...	1980	7406278
amblyomma americanum: sequential histological analysis of adult feeding sites on guinea pigs.		1980	7371734
amblyomma americanum: sequential histological analysis of larval and nymphal feeding sites on guinea pigs.		1980	7364007
evidence for a d1 dopamine receptor in the salivary glands of amblyomma americanum (l.).	adenylate cyclase from the salivary gland of the lone star tick, amblyomma americanum, is stimulated by several derivatives of phenylethylamine; dopamine, noradrenaline, adrenaline and isoproterenol. octopamine and iota-dopa had no effect on basal adenylate cyclase activity. dopamine had the highest potency and the lowest ka, 0.4 micron; followed by adrenaline and noradrenaline, 23 micron; and isoproterenol, 0.15mm. when either noradrenaline or adrenaline was added to dopamine, each at its maxim ...	1981	7346526
neurons sensitive to 2,6-dichlorophenol on the tarsi of the tick amblyomma americanum (acari: ixodidae).		1981	7328604
resistance and cross-resistance of guinea pigs to dermacentor andersoni stiles, d. variabilis (say), amblyomma americanum (linnaeus), and ixodes scapularis say.	the ability of guinea pigs to acquire resistance to dermacentor andersoni and amblyomma americanum was determined by repeatedly infesting separate sets of guinea pigs with tick larvae. resistance was measured in terms of reduced numbers successfully engorging and reduced weight of those ticks that engorged. an 83% reduction in numbers of larvae engorging and a 64.5% reduction in the weight of engorged larvae were seen between the first and second infestations with d. andersoni. guinea pigs exhib ...	1981	7328454
acaricide susceptibility in the lone star tick: assay techniques and baseline data.		1981	7320318
control of the lone star tick in oklahoma parks through vegetative management.		1981	7320314
human 'seed tick' infestation. amblyomma americanum larvae.		1981	7316562
cutaneous basophil responses and immune resistance of guinea pigs to ticks: passive transfer with peritoneal exudate cells or serum.	resistance to infestation by larval amblyomma americanum or rhipicephalus sanguineus ticks was transferred to naive guinea pigs with peritoneal exudate cells (pec) or serum from donors immunized by prior infestation with homologous tick larvae. in the a. americanum system, pec transfer induced 87% tick rejection, which was similar to the level of resistance in actively sensitized hosts. in the r. sanguineus system, pec conferred resistance (39% rejection) that was weaker than in actively sensiti ...	1981	7299125
suitability of birds and mammals as hosts for immature stages of the lone star tick, amblyomma americanum (acari: ixodidae).		1981	7288841
response of hypersensitized guinea pigs to the feeding of amblyomma americanum ticks.	guinea pigs acquired resistance to the feeding of immature amblyomma americanum ticks after a single infestation. the initial larval and nymphal feedings resulted in cumulative mortalities of 27.2 and 28.9%, respectively. the second and third larval infestations yielded cumulative mortalities of 50.5 and 52.4%, compared to 18.9 and 24.4% cumulative mortality from controls. second and third nymphal feedings resulted in 75.7 and 73.4%, and ticks from controls exhibited 36.6 and 34.7% cumulative mo ...	1981	7267146
success of tick feeding on calves immunized with amblyomma americanum (acari: ixodidae) extract.		1981	7265136
alveolar structure of salivary glands of the lone star tick, amblyomma americanum (l.): unfed females.	alveoli in the salivary glands of unfed amblyomma americanum (l.) females (postnymphal ticks that had not yet taken a bloodmeal as an adult) were studied. as in other species of female ixodid ticks, the salivary glands consisted of three alveoli, one agranular and two granular. the agranular alveoli were directly attached to the anterior portion of the main salivary duct, consisted of approximately 13 to 14 cells, and were without valves. six peripheral cells had tortuous, plasma membrane infold ...	1982	7200514
pressurized sprays of permethrin on clothing for personal protection against the lone star tick (acari: ixodidae).		1982	7161438
antibody- and cell-mediated immune resistance by guinea pigs to adult amblyomma americanum ticks.	naive and actively and passively sensitized guinea pigs were infested with adult amblyomma americanum ticks. naive hosts allowed for 75-81% tick yield, 518-581 mg mean tick weight and an average tick feeding period of 12-13 days. actively sensitized and challenged hosts, however, allowed only 47% tick yield (38.9% rejection), replete individuals were significantly reduced in weight (66.1% weight decrease) and required slightly longer time to feed (14 days). passively sensitized hosts were given ...	1982	7149113
immune serum transfer of cutaneous basophil-associated resistance to ticks: mediation by 7sigg1 antibodies.	guinea pigs acquired resistance to amblyomma americanum larval ticks after one infestation, resulting in 46% tick rejection when challenged. intravenous transfer of immune serum from twice-infested hosts to naive animals conferred a significant level of immunity resulting in 18 to 30% tick rejection. the minimum effective dose of serum was 3 ml per recipient, and heating the serum at 56 degrees c for 4 hr had no effect on serum activity. fractionation of whole immune serum by gel filtration chro ...	1982	7142697
comparison of habitat modification, animal control, and standard spraying for control of the lone star tick.		1982	7142558
regulation of feeding and ovipositional success of amblyomma americanum ticks.		1982	7128750
growth in lone star ticks, amblyomma americanum (acari: ixodidae), feeding on cattle: a laboratory study.		1982	7120307
ablation of immunity to amblyomma americanum by anti-basophil serum: cooperation between basophils and eosinophils in expression of immunity to ectoparasites (ticks) in guinea pigs.	basophils infiltrate the skin and other tissues as part of t lymphocyte and/or antibody-mediated immune responses to certain protein antigens, viruses, tumors, and parasites. although basophils may comprise a significant fraction of leukocytes in these reactions, their precise role has been poorly understood. guinea pigs expressing acquired immunity to the tick amblyomma americanum develop basophil- and eosinophil-rich cutaneous inflammatory responses at tick feeding sites, and tick rejection is ...	1982	7086142
blood eosinophil and basophil responses in guinea pigs parasitized by amblyomma americanum ticks.	guinea pigs sensitized to tick feeding by a previous infestation express immune resistance when challenged. this state is associated with large accumulations of eosinophils, and especially of basophils, at cutaneous sites of tick feeding. the present study shows that primary and secondary tick feeding stimulate blood eosinophilia and basophilia that reflect the infiltration of these cells in the skin. primary feeding of amblyomma americanum larvae resulted in a mean tick yield of 81%, mean tick ...	1982	7081550
protein changes in the salivary glands of the female lone star tick, amblyomma americanum, during feeding.		1982	7077436
systematic efficacy of ivermectin mk-933 against the lone star tick.		1982	6896882
pressurized sprays of permethrin and deet on clothing for personal protection against the lone star tick and the american dog tick (acari: ixodidae).		1983	6875081
metazoan parasites of the eastern cottontail rabbit in western kentucky.	forty-five eastern cottontail rabbits (sylvilagus floridanus allen), collected over a 15 mo period from two areas of western kentucky, were examined for disease conditions, helminth and arthropod parasites. a single lymphosarcoma, two cutaneous papillomas and the following parasites were identified: hasstilesia tricolor, taenia pisiformis, cittotaenia variabilis, raillietina stilesiella, obeliscoides cuniculi, trichuris leporis, longistriata noviberiae, trichostrongylus calcaratus, dermatoxys ve ...	1983	6842731
strategic treatment of pastured beef cattle with acaricides: effect on populations of the lone star tick (acari: ixodidae).		1983	6826885
antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut.	blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ...	1982	6803626
ixodid ticks on feral swine in florida.	more than 99% of the 645 feral swine (sus scrofa l.) in southern florida harbored ixodid ticks. dermacentor variabilis (american dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. amblyomma maculatum (gulf coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. amblyomma americanum (lone star tick) and ixodes scapularis (black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. pigs ...	1984	6737605
amblyomma americanum: a potential vector of lyme disease in new jersey.	amblyomma americanum is a likely secondary vector of lyme disease in new jersey. ticks of this species were removed from the site of the characteristic skin lesion known as erythema chronicum migrans on two patients with the disease, and the lyme disease spirochete was isolated from nymphs and adults of this species. that a. americanum is a potential vector is supported by its similarities to ixodes dammini, the known tick vector, in seasonal distribution and host utilization. the extensive rang ...	1984	6710158
effect of host age on the expression of acquired resistance to ticks.	young guinea-pigs (350 g) expressed significantly greater levels of acquired resistance to challenge by larval amblyomma americanum ticks than older guinea-pigs (520-800 g). this finding suggests that younger guinea-pigs are immunologically more responsive to tick infestation than older mature individuals. therefore, host age is an important variable in evaluating acquired resistance to ticks.	1984	6698176
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
lone star tick sighted in newport county.		1983	6578558
bovine resistance to amblyomma americanum ticks: an acquired immune response characterized by cutaneous basophil infiltrates.	purebred holstein calves acquired resistance to amblyomma americanum adult ticks after 1 infestation and expressed resistance during a challenge infestation 26 days later. tick yields from resistant animals were normal, but mean tick weight and egg-mass weight were reduced significantly (31 and 32%, respectively). cutaneous cellular responses at tick feeding sites in primary (naive) hosts consisted almost exclusively of mononuclear cells, until 24-h post-infestation when granulocytes appeared. a ...	1984	6543047
ticks on white-tailed deer fawns from southern illinois.	seventy-six white-tailed deer (odocoileus virginianus (zimmermann] fawns captured on crab orchard national wildlife refuge in southern illinois during june-july 1980-1983 were aged and examined for ticks. the prevalence of ticks (amblyomma americanum (linnaeus, 1758) and dermacentor variabilis (say, 1821] was 80%; intensity of infestation ranged from one to 123 ticks per fawn, averaging 21.6. tick intensity correlated poorly with age suggesting that there were other, more important determinants ...	1984	6530716
aerial application of diazinon granules for area control of the lone star tick (acari: ixodidae).		1984	6512070
characterization of tick antigens inducing host immune resistance. i. immunization of guinea pigs with amblyomma americanum-derived salivary gland extracts and identification of an important salivary gland protein antigen with guinea pig anti-tick antibodies.	guinea pigs immunized by subcutaneous injection of an emulsion of incomplete freund's adjuvant (ifa) containing tick salivary gland extract antigens (sga) from partially fed female ticks expressed a significant level of tick rejection when challenged 17 days later. this level of tick rejection was similar to animals actively sensitized by tick feeding and challenged at the same time. sga emulsified with complete freund's adjuvant (cfa) or administered with saline was ineffective. however, ticks ...	1984	6491289
economic thresholds for lone star ticks (acari: ixodidae) in recreational areas based on a relationship between co2 and human subject sampling.		1983	6408150
immunohistochemical localization of adenosine 3':5'-cyclic monophosphate in female ixodid tick amblyomma americanum (l.) salivary glands.	localization of adenosine 3':5'-cyclic monophosphate (cyclic amp) in alveoli of salivary glands of female amblyomma americanum (l.) was accomplished with an indirect immunofluorescent technique. little cyclic amp fluorescence was seen in type i alveoli in glands of unfed females but considerable fluorescence was seen in type i alveoli of glands obtained from females that had fed. the most intense cyclic amp fluorescence was observed in complex granular cells of type ii and iii alveoli in glands ...	1983	6298395
ultralow-volume mists of chlorpyrifos from a tractor-mounted blower for area control of the lone star tick (acari: ixodidae).		1984	6210316
effect of age, application date, and life stage on the susceptibility of free-living lone star ticks (acari: ixodidae) to acaricides.		1984	6210315